INNOVATION (Strategic alliances) Essay Example | Topics and Well Written Essays - 2000 words

Development (Strategic coalitions) - Essay Example In business, development can be characterized as the abuse of new thoughts that discover acknowledgment in the market. These thoughts, regularly, are consolidated into new procedures, innovation, best practices and structures (Sarkar 2007, p.2). A portion of these thoughts may wind up making a total upgrade an organization’s activity and scope of items. A large portion of the enhanced items depend on the thoughts of others or a change of existing items. In synopsis, development process includes; getting another thought or adjusting an old one, rearrangement of existing chances or those that can be advanced, decision of best other options and utilization of the procedure and the thought (Sarkar 2007, p.2). Development might be because of the need to address the issues of purchasers or improve the method of getting things done. Organizations that neglect to grasp development have frequently wound up left behind by their rivals, prompting the loss of their market specialty. The attention on the hypotheses of advancement fluctuates in light of the fact that there are various perspectives on the procedure of advancement and the components that lead to the improvement of development. The speculations may concentrate on; (a) mechanical turn of events, R&D and specialized research works in an organization, (b) the person who makes and builds up the new components, and (c) issues of advancement in the commercial center (Sundo 1998, p.4). It includes the trading of innovation between at least two organizations. Vital coalitions are portrayed by hazard sharing and common duty in regard to the accomplishment of determined financial and innovative objectives and targets. These unions will in general emerge from the eagerness and want of one firm to help the other in by and large advancement of the firm business or potentially misuse of certain mechanical resources portfolio. A model is the point at which the organizations in the collusion need to (a) structure a joint endeavor in research and dissemination, or (b) enter a joint improvement understanding, or (c) enter

May Day Celebration in New France free essay sample

Also, minor celebrations, primarily strict in character, were various, to such an extent that their recurrence even in the long periods of development was the subject of objection by the common specialists, who felt that these occasions took by and large an excessive amount of time from work. Sunday was a day of love as well as of diversion. Clad in his best attire, each one went to Mass, whatever the separation or the climate. The area church in reality was the symbol of town solidarity, for it assembled inside its dividers every Sunday morning all genders and ages and positions. The habitant didn't separate his religion from his work or his diversions; the outward signs of his confidence were not to his brain things of a different universe; the congregation and its ministers were the middle and soul of his little network. The entire wide open assembled about the congregation entryways after the administration while the capitaine de la cote, the nearby delegate of the intendant, read the pronouncements that had been sent to him from the seals of the forceful at the Chateau de St. We will compose a custom article test on May Day Celebration in New France or on the other hand any comparable subject explicitly for you Don't WasteYour Time Recruit WRITER Just 13.90/page Louis. That obligation over, there was a talkative trade of neighborhood tattle with a retailing of such news as had spilled through from France. The group at that point softened away in gatherings to spend the remainder of the day in games or moving or in agreeable visits of one family with another. Source

How Long Does Phenobarbital Stay in Your System

How Long Does Phenobarbital Stay in Your System Addiction Drug Use Prescription Medications Print How Long Does Phenobarbital Stay in Your System? By Buddy T facebook twitter Buddy T is an anonymous writer and founding member of the Online Al-Anon Outreach Committee with decades of experience writing about alcoholism. Learn about our editorial policy Buddy T Medically reviewed by Medically reviewed by Steven Gans, MD on August 13, 2016 Steven Gans, MD is board-certified in psychiatry and is an active supervisor, teacher, and mentor at Massachusetts General Hospital. Learn about our Medical Review Board Steven Gans, MD Updated on February 16, 2020 Blend Media / Getty Images More in Addiction Drug Use Prescription Medications Cocaine Heroin Marijuana Meth Ecstasy/MDMA Hallucinogens Opioids Alcohol Use Addictive Behaviors Nicotine Use Coping and Recovery Phenobarbital is a long-acting barbiturate typically prescribed to control seizures. In some circumstances, it is used in treating withdrawal and for other purposes.?? Knowing how it acts in your system and for how long can help you understand the precautions to take to avoid dangerous drug interactions and possible overdoses. How Phenobarbital Acts in Your System Phenobarbital can be administered as an injection, a liquid elixir, or tablets. Each has their own speed of taking effect and appropriate dosages. Tablets or elixirs begin to act in 30 to 60 minutes, and their duration lasts for 5 to 12 hours, depending on the dosage and individual metabolism.?? The plasma half-life of phenobarbital in adults is an average of about 79 hours and 110 hours in children. That means that only half of the active ingredients have stopped exerting their effect in that time. It takes five to six half-lives for drugs to be fully eliminated from your system. Phenobarbital is metabolized by the liver and excreted in the urine. It can be detected in the urine for up to 7 days after a dose.?? If you take a urine drug screen while on phenobarbital, it will likely test positive for barbiturates. Phenobarbital can interact with many prescription and nonprescription medications, supplements, and herbal products while it is in your system. It is important to talk to your doctor about all of your medications to avoid these interactions, including ones you might start or stop taking. Some drugs of special concern with phenobarbital include blood thinners, Antabuse, Vibramycin, Fulvicin, hormone replacement therapy, monoamine oxidase inhibitors, oral steroids, sedatives, sleeping pills, tranquilizers, and medications for anxiety, depression, pain, asthma, colds, allergies, and seizures.?? Dont drink alcohol while phenobarbital is in your system as it can worsen side effects. Phenobarbital can harm a fetus, so it shouldnt be used if you plan to become pregnant, and it shouldnt be used if you are breastfeeding.?? Birth control pills and other hormonal contraceptives may be less effective when you are taking phenobarbital, and you may need to use a different form of birth control. Take Phenobarbital Only as Prescribed One reason to know how long phenobarbital remains in your system is that it is addictive which means taking larger doses, taking it more often, or taking it longer than prescribed could increase the risk of addiction.?? Because phenobarbital can become habit-forming, you should not take the medication if you drink or have ever drunk large amounts of alcohol, used illicit drugs, or overused or used for nonmedical purposes any prescription medications. Dont Stop Taking Phenobarbital Suddenly Also, do not stop taking phenobarbital suddenly without consulting your healthcare provider. Stopping suddenly can cause you to experience withdrawal symptoms which can include:?? AnxietyMuscle twitchingUncontrollable shaking  of a part of the bodyWeaknessDizzinessChanges in visionNauseaVomitingSeizuresConfusionDifficulty falling asleep or staying asleepFainting If you wish to stop taking phenobarbital, your doctor will probably gradually decrease your dosage. Overdose Symptoms of phenobarbital overdose include heart failure, low blood pressure, weak pulse, uncontrollable movements of the eyes, loss of coordination,  drowsiness,  slowed breathing, confusion, delirium, headache, sleepiness, coma, and large blisters.?? If you think someone has had a phenobarbital overdose, call the poison control center at 1-800-222-1222. If the person has collapsed or is not breathing, call 9-1-1 immediately.

Preference Travelling - 788 Words

Traveling Experiences Abstract This research studies the relationship between cognitive psychology best suited in studying human behavior and traveling as part of one of our social activities when choosing destination sets: rejection, preferences, behavior in the planning of a pleasure vacation, travel distance to take into consideration, and the possibility of hiring a travel agent to minimize local distances rather than total distance depends on our level of education and personality, how engaging traveling is to our cognitive behavior, and how it affects our states of consciousness will be important to our decisions we take vacations and travel, therefore, making this observational learning a lifetime experience. As we can†¦show more content†¦We have seen how cognitive psychology goes in tandem with psychoanalysis when taking decisions, in traveling, in order to rest and go out of the daily routine that we go through during our adulthood, and the gratifications that come with traveling as therapeutic way. Cognitive psychology has been incorporated to explain these concepts of psychoanalysis without acknowledging this influence. â€Å"Traveling, for instance, for the employees is a defense mechanism where personal conflicts, repressed wishes, wake up our state of consciousness and face those psychological disorders that will eventually fade away with a deserved vacation by travelling no matter how far it might be, (Freud Sismund, Defense Mechanism, late 19th century), in order to deal with neurotic anxiety, reality, and moral anxiety, tiredness, besides physiological problems that comes with putting off vacationing for too long when you work too hard. Participating in open-door activities is more rewarding to our cognitive functions than visiting or participating in traditional sports, or visiting a museum. Being outdoors enjoying natural attractions activated our brains and nervous systems, making us renew and positive in attitude. From a psychological standpoint, all these observational learning brought personal fulfillment as human interaction depends on our relationship to nature. Ankomah, P.K., Crompton, J.L., amp; Baker,Show MoreRelatedNostalgia Marketing3188 Words   |  13 Pagesnostalgia as â€Å"a preference (general liking, positive attitude, or favourable affect) toward objects (people, places, or things) that were more common (popular, fashionable, or widely circulated) when one was younger†, this means a special inclination for products and activities that by one reason or other cannot be commonly experienced or are not available any more. (Schindler and Holbrook, 2003) Holak and Havlena (1998) complement this definition by stating that nostalgia is not a preference for theseRead MoreA Study On Mode Choice Modeling1928 Words   |  8 PagesPij= evij / ∑ N n=1 evij †¢ Vij – utility function of mode j for individual i; †¢ Vin – utility function of any mode n in the choice set for an individual i; †¢ Pij – probability of individual i selecting mode j; and †¢ N– total number of available travelling modes in the choice set for individual i. Multinomial Probit Modal is similar to logit modal but the only difference between these modal lies in the assumption about the distribution of the error. In logit modal, it follows standard logistic distributionRead MoreConsumer Theory and Horizontal Axis45363 Words   |  182 Pagesadvertising budget would be represented by the integer values along a line segment that runs between the two points: (a) (3; 000; 3; 600) and (1; 800; 6; 000). 3. Bella s budget line for x and y depends on all of the following except: (c) her preferences between x and y. 4. Billy Bob wants to gain some weight so that he can play football. Billy eats only milkshakes and spinach. Milkshakes cost him $1 each and spinach costs $2 per serving. A milkshake has 850 calories and a serving of spinachRead MoreThe System Of Working Of Railways1521 Words   |  7 Pagesquestions. So basically my questionnaire is as following: Please tick the answer according to your response†¦ Q1. What is your preference mode of travel for your vacations? †¢ NZ Trains †¢ Own Car / Taxi †¢ Metro Q2. How frequently you travel for vacations? †¢ Once a month †¢ Once in a Quarter †¢ 2-3 times in every six months †¢ Once a year Q3. What’s your budget allocation for travelling? †¢ $ 10-20 †¢ $ 20-30 †¢ $ 30-50 †¢ $ 50-500 †¢ $ 500-1000 Q4. Circle the importance factor influence choosing mode of transportRead MoreA Study Of The Pos Of Tourism?902 Words   |  4 PagesThe above chart shows the average spending of tourists in the UK during their period of travel. Therefore, it can be said that the other economies of the world has been increasing their spending power while they are travelling and availing hospitality services in the UK. It can be proved by the spending pattern of Chinese tourists (Gardiner and Kwek, 2017). The economic base of United Kingdom is very strong that explains that the choice of the tourists for a hotel during length of stay. In accordanceRead MoreMedia Tourism Of Sherlock Holmes Museum1451 Words   |  6 PagesJ ,2000). The Sherlock Holmes Museum was built for the purpose of making money. At the beginning, the founder of the museum had a plan to develop the tourist industry. As a result, everything in this museum has been designed to match tourists’ preferences. I can provide a personal example. I visited the museum myself and read the letters that the museum has received from Sherlock Holmes fans. The museum staff told me that these fans wanted to write letters to Sherlock Holmes but have no true addressRead MoreTop Mobile Travel Apps to Plan Amazing Trips Essay768 Words   |  4 PagesThey can be your best travel guide whether you want to select any holiday spot, book hotels or flights, compare different travel deals, accommodations or attractions and much more. So, here we go— Flights With Friends—If you love the idea of travelling in a group (either family or friends), then this mobile travel app (www.FlightsWithFriends.com) is a must for you. It will provide a list of various travel choices before you on a single page including available flight hotel accommodations, travelRead MoreExternal Factors That Influence Tourism Development And Demand2684 Words   |  11 Pagesmarket in all the developed markets. This makes the senior travelers market a promising market for tourism marketers and managers both at present and in the future because they not only have increased disposable income, but also sufficient time for travelling (Jang Wu, 2006). The majority of these seniors are capable, both physically and financially, of going for vacation trips, and many of them have strong motivation to travel for pleasure. The tourism industry is highly vulnerable and the industryRead MoreEssay about Kinematics1733 Words   |  7 Pagesbring uniform acceleration . The change in velocity should stay the same. Sources of Error: The dynamics cart may not be travelling in a straight line. This travelling causes the velocity to change. This can happen because a straight track is not used. If the dynamics cart is not travelling straight, many other measurements can be affected. This is because if it is not travelling straight, the distance is changed as well as the time. It will take the dynamics cart longer to travel down the 2m boardRead MoreInternational Marketing1398 Words   |  6 PagesEast. The performed surveys through different questioners, including mail surveys, along with face-to-face interviews and numerous phone interviews, exclusively to Mayo Clinic policyholders. The face-to-face interviews focused on demographics, preferences, healthcare behavior, the Mayo brand awareness and the significance of Mayo Clinic coverage as a benefit. The phone surveys however focused mainly on brand awareness and the questions were completely differently structured. The questions were either

Mental Illness And Its Effects On People s Mood,...

Mental illness, a medical condition, are disorders that can affect people’s mood, thinking, and behavior. Many people don’t pay much attention to these disorders, because they are not familiar with psychiatric illness. Not paying attention to detecting and treating mental illness is an issue, because it can increase the risk of violence more than treated mentally ill people. For example, the failure to treat the ill can have dire consequences because it can increase the risk of mass shootings. Being able to recognize the signs of mental illness is important to help prevent incidents because most people are not informed well and don’t recognize the symptoms of mental illness on time, which can be very risky to the community. Although many crimes could be linked with mental health issues, not all mentally ill are dangerous. Although it is considered a myth by recent discoveries, many people believe that all mentally ill people are dangerous. The majority of people fear mentally ill people because they relate the mentally ill with school massacres and shootings. For example, when the Virginia Tech massacre happened many people started proposing gun policies to prohibit guns from people who had any sort of relation with mental illness for fear of another lose mad man. According to a survey a national public opinion survey that tested the public attitudes about mental illness, Overall and among People with and without Experience with Mental Illness, â€Å"Almost half of respondentsShow MoreRelatedSymptoms And Symptoms Of Multiple Personality Disorder773 Words   |  4 PagesAs an overview, schizophrenia is a brain mental disorder. A schizophrenic person has lost touch with reality. They may also experience hallucinations, delusions, hearing voices, seeing things that are not there.They may believe that other people are threatening to harm them. Sometimes they don t make any sense when they talk. The disorder makes it hard for them to keep a job or take care of themselves. The disorder usually starts in a person’s early twenties to late twenties, and it affects aboutRead MoreWhat Is Bipolar Disorder?1546 Words   |  7 PagesBipolar disorder is a brain disorder that causes uncommon shifts in mood, energy, ability to perform daily routines and another terminology is â€Å"manic-depressive illness†. According to American Psychiatric Association â€Å"Bipolar diagnosed patients can lead full and productive lives†. This isn’t by any means harmful or threatening but can be well managed, controlled and yield positives because it can be treated. How Can Bipolar Behavior Be Recognized? An individual can be in one of the two unalike phasesRead MoreMental Disorders And Criminal Behavior1293 Words   |  6 Pages Running head: MENTAL DISORDERS CRIMINAL BEHAVIOR Mental Disorders and Criminal Behavior Courtney Edwards Thomas University Abstract The purpose of this research paper is to provide information on the distinct types of mental illnesses as they correlate with criminal behavior. There are so many disorders in which exist in today’s society. These include: schizophrenia, delusional disorders, bipolar disorders, obsessive compulsive disorders, and so much more. Through compulsive researchRead MorePsychological Trauma And Behavior Of The Cold Blood By Truman Capote1139 Words   |  5 PagesPsychological Trauma and Behavior â€Å"In 1990, a landmark case went to trial in Redwood City, California. The defendant, George Franklin, Sr., 51 years old, stood trial for a murder that had occurred more than 20 years earlier. The victim, 8-year-old (Susan Kay Nason, was murdered on September 22, 1969). Franklin s daughter, Eileen, only 8 years old herself at the time of the murder, provided the major evidence against her father. What was unusual about the case is that Eileen s memory of witnessing theRead MoreModern Medicine, Traditional Medicine And Complementary And / Or Alternative Medicine1517 Words   |  7 Pages`Mental health has three types of treatments. Western Scientific Medicine, Traditional Medicine and Complementary and/or Alternative Medicine. Western Scientific Medicine Definition: A system in which medical doctors and other healthcare professionals (such as nurses, pharmacists, and therapists) treat symptoms and diseases using drugs, radiation, or surgery. Also allopathic medicine, biomedicine, conventional medicine, mainstream medicine, and orthodox medicine. Traditional Medicine Definition:Read MoreI Am A Mad Genius982 Words   |  4 Pagesgenius, and madness, or is it just a matter of chance? 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Mental health is something a normal, healthy functioning human being has whe n everything in their head is in order. A mental illness is theRead MoreMental Illness Is A Condition That Affects People s Behaviors, Moods, And Thinking1122 Words   |  5 PagesMental illness is a condition that affects people’s behaviors, moods, and thinking. There are many types of mental illnesses like anxiety, depression, dementia, and schizophrenia. 60 million Americans have a mental illness. Mental illness affects one out of four adults and one out of five children. Most mental illnesses can be helped with therapy or medicine, unfortunalty most cannot be cured. Most people with a mental illness do not seek treatment and live with this illness everyday of their livesRead MoreWhat Does It Mean For The Health Of A Nation? Essay1648 Words   |  7 Pagesbut does this mean we are healthy? What does it mean to measure the health of a nation? 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Marshall Williams, of the Centers for Disease Control and Prevention, approximately

Epoxy Resin Free Essays

string(37) " no diffraction peaks of GOFO at 10\." Epoxy resin is a type of thermosetting polymer, commercially available in different forms, has a wide range of application in aerospace, coating, electric insulation and marine application due to its outstanding performances, easy handling and low cost [1-5]. Epoxy high inner stress, brittle texture, inferior impact resistance, weak creep resistance and poor moisture resistance, limited its application in other industrial areas [6]. So, the epoxy was mixed with polymers[7], clays, metal [8], carbon nanotube [9], graphene[10], and graphene oxide[11] to overcome its limitations. We will write a custom essay sample on Epoxy Resin or any similar topic only for you Order Now Graphene oxide (GO) is a graphite derivative that produced through oxidation of graphite using various methods. Graphene oxide is a 2D sheet with oxygen functional at the surface (hydroxyl, carbonyl, and epoxide) and (carboxyl) at its edge [12,13]. Graphene oxide is a promising material as polymer reinforcement, due to its high mechanical properties[14], excellent thermal stability[15], and good insulation properties [16]. Moreover, graphene oxide high surface area, high aspect ratio, excellent sheet flexibility, reactivity sites, and good dispersion in most common solvent favored its use a composites material for polymeric material. The Graphene oxide tends to improve the mechanical properties, thermal stability, insulator, and dielectric properties of the various commercial epoxy resin. However, Graphene oxide sheets tend to aggregate either by Van der Waals force or ?-? stacking interaction, which would decrease the improvement effects of graphene sheets in epoxy matrix [17]. Therefore, graphene oxide was modified either through covalent bonds or by ?-? interaction to reduce these aggregation phenomena and enhanced epoxy properties. For instance, Wan et al improved epoxy tensile strength and modulus by 75% and 15% through mixing epoxy with graphene oxide modified with DGEBA (diglycidyl ether of bisphenol-A) [18].Also, Liu et al enhanced epoxy glass temperature and tensile strength by 26oC and 31% using grafted graphene oxide [5]. Sharmila et al prepared Graphene oxide modified with iron oxide nanoparticles, they epoxy composites shown improvements in the tensile, impact, and fracture strength [19]. Fluorinated polymer is polymer contain carbon-fluorine bonds and they has been applied in many domestic and industrial application due there excellent thermal stability, anti-chemical corrosion, weathering resistance, high dielectric conductivity, and low surface energy [20-22]. However, the high market price of the fluoropolymers and poor miscibility in epoxy resin restricted their applications [23]. Thermal stability, roughness, and corrosion resistance were improved for epoxy resin modified with a fluorinated polymer [24-27]. The fluorine atoms reduced the crosslinking density of the epoxy resin and fluoropolymer, reducing the mechanical properties of the epoxy [28]. The grafting of the fluorinated polymer into carbon base material such as carbon nanotube, fluorinated graphene, and fluorinated graphite may combine the excellent properties of carbon base material and fluorine group’s properties. The miscibility was improved with enhancement of the mechanical properties, thermal stability, surface properties, and electric properties. Yang and coworkers grafted fluorinated polymer on reduced graphene oxide coated with dopamine. The modified graphene showed excellent dispersion in the ferroelectric polymer matrix with good high dielectric constant and low dielectric loss [29].Que et al modified epoxy resin (DGEBA) with trifluoromethyl containing polyimide structures. Compared with neat epoxy, they found that the modified epoxy shown better thermal stability with 18 to 55 % char yield at 800 0C, water contact angle (94.9–105.0 °), higher toughness, and lower water absorption (0.47–0.95 %). The tensile shear of modified epoxy was lower than the neat epoxy, the fluorine groups decreased epoxy surface energy which further reduced the adhesion strength compared with unmodified epoxy [7]. In this work, graphene oxide was modified with Hexadecafluoro (1, 10) decanediol through one-step reaction. Modified graphene oxide was mixed with epoxy resin in various loading. Then, the mechanical properties, thermal stability, water contact angle water uptake, and alkaline corrosion resistance were examined for epoxy composites. Results and Discussion:   The surface functionalization of GO was confirmed by FTIR, XRD, XPS, Raman spectroscopy, and TGA. Fig. (1) shows the FTIR spectrum of GO and GOFO. For GO typical peaks were observed at 3390 cm-1 (stretching vibration of C-OH), 1041 cm-1 (stretching vibration of C-O), 1374 cm-1 (deformation vibration of C-OH), 1261 cm-1 and 877 cm-1 (stretching vibration of C-O-C), and 1734cm-1 (stretching vibration of C=O). The peak at 1619 cm-1 is attributed to the skeletal vibration of the graphitic of GO [30]. After reaction with FO new peaks appeared. The peaks at 1178 cm-1 (stretching vibration of C-F) [31], at 2966 cm-1 (bending stretching of C-H), and at 1441 cm-1 (stretching vibration of C-H) from the perfluoro compound. The peak at 1080 cm-1 was related to stretching vibration of ester bond C-O-C. These results indicated that FO was successfully grafted onto GO surface.The XRD patterns of Graphite, GO, and GOFO was shown in Fig. (2) and the interlayer distance was calculated using Bragg equation. Pristine graphite is shown a typical peak at 26.410 with an interlayer spacing of 0.337 nm [32]. This peak shifted to 11.020 (corresponding to an interlayer space of 0.802 nm) after graphite was oxidized to GO, that was due to the formation of oxygen-containing functional groups on a graphite oxide surface and water molecules trapped between the layers [33]. The functionalization of GO with FO shifted the peak from 11.020 to 10.080 (corresponding to an interlayer space of 0.676nm), suggested that GO was modified with FO. Another broad diffraction peak was observed at 22.760, which suggests the formation of few layers of reduced graphite oxide. To further study the structural differences between graphite, GO, and GOFO, the graphitic crystal size was calculated using Sheerer equation and the number of layers was calculated based on crystal size. Graphite had a large crystal size of 21.28nm with 63-64 graphene layers. After oxidation to GO, the crystal size decreased to 10.92nm and the number of layers decreased to 10-11 graphene layers. The crystal size of GOFO was 3.78nm with 5 -6 layers of the modified graphene sheet. In order to study the exfoliation of GOFO into the epoxy matrix, the XRD patterns of EGOFO composites and neat epoxy were investigated as shown in Fig. (3). For neat epoxy, two broads peaks centered at ?70 and ?180 were observed due to the amorphous nature of neat epoxy. All Epoxy composites show the same characteristic diffraction peak as neat epoxy and no diffraction peaks of GOFO at 10. You read "Epoxy Resin" in category "Papers"080 and 22.760 were observed [34]. That’s confirmed that GOFO was highly exfoliated into the epoxy matrix. Although, the highly exfoliated level of GOFO sheets in the epoxy matrix cannot represent a good dispersion was obtained in the epoxy composites [35]. The thermographic analysis in Fig. (4) represents the thermal stability of GO and GOFO under a nitrogen atmosphere. Graphene oxide shows 8.404% weight loss between 50 0C -100 0C, due to evaporation of residual water trapped between the layers. A significant weight loss of 29.53% was observed between 100 0C – 250 0C, that’s due to decomposition of labile oxygen functional groups to H2O, CO, and CO2 [22,10].Compared to GO, GOFO was more stable with 3.48% weight loss was observed between 50 0C -100 0C can be assigned to evaporate of residual water trapped between the layers, which was lower than GO. Between 100 0C – 250 0C, 8.18% weight loss was found due to decomposition of the reaming oxygen functional groups. Then, 12.44% weight loss was observed between 250 0C – 550 0C, that can be assigned to the decomposition of the bond between GO and perfluoro compound. In addition, compared with 48.59% weight loss at 700 0C for GO, GOFO undergoes 20.83% weight loss. The above data can be due to GO, bosses high amount of oxygenated functional groups, while GOFO possesses low oxygenated functional groups due to functionalization by FO. The above results confirmed that GOFO was more stable than GO.Raman spectroscopy was applied to explore the structural variations between GO and GOFO. Generally, the graphitic material shows two characteristic peaks, the G peak (~1575 cm?1) arises from first-order scattering of the E2g photon of sp2 C atoms and the D peak (~1350 cm?1) from a breathing mode of ?-point photons of A1g symmetry. Also, the intensity ratio ID/IG can be used to evaluate the graphitization degree of the graphitic material, the lower value represented a high degree of graphitization [30]. Fig. (5) shows Raman spectrum results of GO and GOFO. The G and D bands of GO were located at 1599.9 and 1357 cm-1 receptivity, as reported in previous reports [30,36,37]. After functionalization with FO, the G band was shifted to a lower wavelength at 1589 cm-1, no obvious changes were observed for the D band. In addition, the ID/IG intensity ratio of GO increases from 0.96 to 1.062 for GOFO. The changes in the intensity ratio imply that GOFO of graphene structure was restored, which can be due to the removal of oxygen functional groups. The GO and GOFO were characterized using X-ray photoelectron spectroscopy (XPS), the results are shown in Fig. (5) and the elemental analysis is tabulated in Table (1). The GO broad spectrum shows two peaks at binding energies around 286.1 eV and 532.4 eV, which were assigned to C1s and O1s, respectively. The atomic composition of graphene oxide was obtained from XPS broad spectrum and revealed the presence of carbon (71.88%) and oxygen (28.12%). In contrast, the GOFO broad spectrum displayed three peaks at binding energies around 286.1 eV, 532.4 eV, and 686 eV, they can be assigned to C1s, O1s, and F1s respectively. The atomic composition of GOFO obtained from the broad spectrum shown the existence of carbon (71.66%), oxygen (27.34%), and fluorine (1%). The carbon-to-oxygen ratio increased from 1.6 for GO to 2.6 for GOFO, due to functionalization with FO. The C1s XPS spectrum of GO and GOFO are shown in Fig. (6). The C1s spectra can be decomposed into four characteristic peaks: C=C/C-C (non-oxygenated carbon, 284.5 eV), C-OH/C-O-C (hydroxyl, epoxy, and 286eV), C=O (carbonyl, 286.8 eV), and COOH (carboxyl, 288.9 eV) [38]. In comparison, the decomposed C1s spectrum of GOFO shows additional peaks at 287.02eV, 290 eV, and 292 eV, assigned to -C-O- (ether bond), C-F (fluorine), and C-F2 (fluorine) respectively[39]. As shown in Fig. (5), compared with XPS C1s spectrum of GO (Fig. (6)), the peak intestines of C-O and C-O-C were significantly decreased, new peaks appeared. The above results indicated the attachment of FO to graphene oxide surfaces via the reaction with hydroxyl groups of FO with C-O groups on the GO surfaces [40]. As shown in the SEM images of EGOFO composites, the GOFO sheets were well dispersed in the epoxy matrix. GOFO nano-sheets were surrounded tightly by epoxy resin, which indicates a good interfacial interaction between GOFO and the epoxy matrix. Such good interfacial bonding improves the stress transfer from the epoxy matrix to the GOFO nano-sheet and thus enhanced the mechanical properties of epoxy composites. However, due to the presence of incompatible fluorine groups on the GOFO, micro-voids can be observed and such voids could enhance crack initiation which leads to decrease the mechanical properties of epoxy composites[41]. SEM analysis of epoxy composites: The SEM images of epoxy and epoxy composites at fracture site after the tensile test are shown in Fig. (7). The images were used to examine the dispersion and the compatibility of GOFO in the epoxy matrix. Fig. (7a,b) shows neat epoxy exhibited relatively smooth surface with a river-like pattern in the fracture direction, confirmed the brittle nature of epoxy [42]. In contrast epoxy composites displayed rougher, fluctuant surfaces with GOFO nano-sheet pulled out of the epoxy matrix Fig. (7 c,e). Also, epoxy composites SEM images shown that GOFO nano-sheets were well dispersed in the epoxy matrix, a well interfacial interaction between the nano-sheets and epoxy composites Fig. (7 d,f). The good interfacial bonds can effectively transfer the stresses from the epoxy matrix to the GOFO nano-sheets and thus enhanced the mechanical properties of epoxy composites [41]. However, several micro-voids can be observed in all epoxy composites that can be due to the presence of fluorine groups. The low compatibility between the epoxy resin and fluorine groups caused the appearances of micro-voids. Cracks can initiate easily in the micro-voids, then spread through epoxy composites reducing epoxy composites strength. Mechanical properties of epoxy composites: Tensile test:The tensile test was conducted to investigate the effects of GOFO on the epoxy resin performance. Fig. (8) shows the stress-strain curves of neat and epoxy composites, and the results were summarized in table (2). The tensile modulus of pure epoxy was 471 MPa and its changes to 486 MPa (increased by 3.2 % with 0.1 wt. %), 507 MPa (increased by 7.6 % with 0.3wt. %), and 530 MPa (increased by 12.52 % with 0.5 wt. %). The highest tensile modulus was 12.52% compared to neat epoxy corresponding to 0.5% GOFO loading. The increase in the tensile modulus was due to the good dispersion and interfacial interaction between the GOFO and epoxy matrix. That’s led to the good transfer of stress from the matrix to GOFO sheets. However, the tensile strength decreased by 18.35%, 22.15%, and 20.25% with 0.1 wt. %, 0.3 wt. %, and 0.5 wt. %. GOFO loading. The formation of micro-voids between the GOFO sheets in the epoxy matrix due to incompatibility between GOFO sheet and epoxy system due to the presence of fluorine groups. Fracture test:  Ã‚  The effects of GOFO loading on the fracture properties are shown in Table (2) and the stress-strain curves of fracture analysis were shown in Fig. (9). EGOFO composites shown a battened in the fracture modulus and strength to those of neat epoxy upon different loading. The fracture modulus was 1510MPa for neat epoxy. With 0.1, 0.3, and 0.5 wt. % loading of FO, the fracture modulus increased to 2340 ±17.61 MPa, 2324 ±73.5 MPa, and 2450 ±45 MPa respectively, these were 54.97, 53.84, and 62.85% respectively. However, for fracture strength, it’s behaved differently with increasing GOFO concentration. The fracture strength decreased by 13.12% with the addition of 0.1 wt.% GOFO loading and then increased to 13.61% and 16.98% with 0.3 wt.% and 0.5 wt.% GOFO loading respectively. The increase in the fracture modulus and strength can be attributed to improvement in the interfacial interaction between the GOFO and epoxy matrix. That’s allowed better load transfer from the epoxy matrix to the GOFO sheets, which increased both fracture modulus and strength. Thermal stability of epoxy composites:The Thermal stability of the GOFO nanocomposites was investigated by TGA as shown in Fig. (10) and Table (3).T10% and T50% are the temperature of sample weight loss reached 10% and 50 % respectively. Tdec is the sample decomposition temperature. All the specimens showed similar thermal degradation behavior with main weight loss between 3500C to 4500C. They exhibited different weight loss during the onset decomposition stages as shown in the enlarged window. The incorporation of GOFO significantly enhanced the thermal stability of epoxy composites in different trends. Epoxy composite 0.3 wt. % GOFO loading has a higher T5%, T50%, and Tdec compared with other epoxy composites. The T5% and T50% increased by ?13 and ?150C respectively based on pure epoxy. The Tdec increased by ?13 with the same loading compared to pure epoxy. According to the literate, there are two factors effects on the thermal stability of polymer composites: the formation of networks via covalent linkages between them and the crosslinking density [43,44]. The existence of the oxygen functional groups at the edge and the surface of the GOFO, can react with the epoxy resin and increased the crosslinking of the composites. The XRD data showed that GOFO doesn’t have a uniform crystal shape compared to graphite, that makes the GOFO has a poor thermal conductivity. Therefore, with good dispersion of GOFO, it will act as a barrier and reduce the thermal conductivity of the epoxy composites [44]. Water uptake epoxy composites:The influences of water absorbed by the polymeric material can be significantly reduced by incorporating nano-size fillers into polymers [45,46].The water uptake of neat epoxy and its composites filled with GOFO were shown in Fig. (11). The addition of GOFO nano-fillers significantly decreased the amount of water absorbed by epoxy composites. The water uptake by neat epoxy was 0.432%, which decreased to 0.317% , 0.304% , and 0.308% for epoxy composites with 0.1wt.% , 0.3wt.% , and 0.5 wt.% GOFO loading respectively. this phenomenon implied that the addition of nano-size sheet with high aspect ratio provided tortuous pathways for water molecules to enter the epoxy composites and acted as a barrier water transportation through epoxy composites [47]. Another reason can be due to the hydrophobic nature of fluorine groups on GOFO, which can immobilized water molecules and prevented it from diffusion in epoxy matrix[47]. The hydrophobic behavior of GOFO composites:Fig. (12). Shown the air/water contact angle of pure epoxy and its composites. The measurement was performed at room temperature with three repetitions for each sample. From Fig. (12), the incorporation of GOFO increased the contact angle of all epoxy composites. The contact angle increased from 68.70 o  ± 1.73 for the pure epoxy to 83.53 o  ± 1.13 for 0.1 wt. % GOFO, 98.65 o  ± 2.49 for 0.3 wt. % GOFO, and 89.22 o ± 0.70 for 0.5 wt. % GOFO. The changes in the contact angle indicate that epoxy composites show more hydrophobic effects compared to pure epoxy [48]. The GOFO tends to immigrate to the surface of epoxy, due to the low surface energy of the fluorine atoms. They altered the surface energy and increased the hydrophobicity of the epoxy surface. But, with 0.5 wt. % GOFO loading, the contact angle decreased to 89.22 o ± 0.70, the aggregated GOFO nano-sheet at the surface can slightly reduce the polarity of the surface and increased the effects of the reaming oxygenated function groups of the graphene sheet. How to cite Epoxy Resin, Papers

The Microprocessor Essays - Microprocessors, Microcomputers

The Microprocessor Microprocessors Evolution Only once in a lifetime will a new invention come about to touch every aspect of our lives. Such a device that changes the way we work, live, and play is a special one, indeed. The Microprocessor has been around since 1971 years, but in the last few years it has changed the American calculators to video games and computers (Givone 1). Many microprocessors have been manufactured for all sorts of products; some have succeeded and some have not. This paper will discuss the evolution and history of the most prominent 16 and 32 bit microprocessors in the microcomputer and how they are similar to and different from each other. Because microprocessors are a subject that most people cannot relate to and do not know much about, this paragraph will introduce some of the terms that will be in- volved in the subsequent paragraphs. Throughout the paper the 16-bit and 32-bit mi- croprocessors are compared and contrasted. The number 16 in the 16-bit microproces- sor refers how many registers there are or how much storage is available for the mi- croprocessor (Aumiaux, 3). The microprocessor has a memory address such as A16, and at this address the specific commands to the microprocessor are stored in the memory of the computer (Aumiaux, 3). So with the 16-bit microprocessor there are 576 places to store data. With the 32-bit microprocessor there are twice as many places to store data making the microprocessor faster. Another common term which is mentioned frequently in the paper is the oscil- lator or the time at which the processors ?clock? ticks. The oscillator is the pace maker for the microprocessor which tells what frequency the microprocessor can proc- ess information, this value is measured in Mega-hertz or MHz. A nanosecond is a measurement of time in a processor, or a billionth of a second. This is used to measure the time it takes for the computer to execute an instructions, other wise knows as a cy- cle. There are many different types of companies of which all have their own family of processors. Since the individual processors in the families were developed over a fairly long period of time, it is hard to distinguish which processors were introduced in order. This paper will mention the families of processors in no particular order. The first microprocessor that will be discussed is the family of microprocessors called the 9900 series manufactured by Texas Instruments during the mid-70s and was developed from the architecture of the 900 minicomputer series (Titus, 178). There were five dif- ferent actual microprocessors that were designed in this family, they were the TMS9900, TMS9980A, TMS9981, TMS9985, and the TMS9940. The TMS9900 was the first of these microprocessors so the next four of the microprocessors where simply variations of the TMS9900 (Titus, 178). The 9900 series microprocessors runs with 64K memory and besides the fact that the 9900 is a 16-bit microprocessor, only 15 of the address memory circuits are in use (Titus, 179). The 16th address is used for the computer to distinguish between word and data functions (Titus, 179. The 9900 series microprocessors runs from 300 nanoseconds to 500 ns from 2MHz to 3.3MHz and even some variations of the original microprocessor where made to go up to 4MHz (Avtar, 115). The next microprocessor that will be discussed is the LSI-11 which was pro- duced from the structural plans of the PDP-11 minicomputer family. There are three microprocessors in the LSI-11 family they are the LSI-11, LSI-11/2, and the much im- proved over the others is the LSI-11/32 (Titus, 131). The big difference between the LSI-11 family of microprocessors and other similar microprocessors of its kind is they have the instruction codes of a microcomputer but since the LSI-11 microprocessor originated from the PDP-11 family it is a multi-microprocessor (Avtar, 207). The fact that the LSI-11 microprocessor is a multi-microprocessor means that many other mi- croprocessors are used in conjunction with the LSI-11 to function properly (Avtar, 207). The LSI-11 microprocessor has a direct processing speed of 16-bit word and 7- bit data, however the improved LSI-11/22 can directly process 64-bit data (Titus, 131). The average time that the LSI-11 and LSI-11/2 process at are 380 nanoseconds, while the LSI-11/23 is clocked at 300 nanoseconds (Titus, 132). There are some great strengths that lie in the LSI-11 family, some of

The eNotes Blog Gabriel Garcí­a Márquez Dead at87

Gabriel Garcà ­Ã‚ ­a Mrquez Dead at87 Celebrated Colombian  author Gabriel Garcà ­Ã‚ ­a Mrquez  died today at the age of 87 after a recent hospitalization for multiple infections. His death comes two years  after it was reported he was suffering from dementia. â€Å"It is not true that people stop pursuing dreams because they grow old, they grow old because they stop pursuing dreams.† ―  Gabriel Garcà ­Ã‚ ­a Mrquez In his extroadinary lifetime Mrquez received widespread acclaim for his novels and short stories, including  One Hundred Years of Solitude,  Love in the Time of Cholera and  Chronicle of a Death Foretold.  One Hundred Years in particular became incredibly popular, selling more than 50 million copies worldwide in over 25 languages. With his works Mrquez  stood as an ambassador for Latin American literature, and the father of magical realism. When he won the Nobel Prize for Literature in 1982, he dedicated his lecture to the spirit of Latin America, and revealed to the world its inextricable ties to his particular writing style: We have had to ask but little of imagination, for our crucial problem has been a lack of conventional means to render our lives believable. Mrquez is survived by his wife Mercedes and his two sons. He died at home in Mexico City. His memoirs remain unfinished. Gabriel Garcà ­Ã‚ ­a Mrquez Biography at Works of  Gabriel Garcà ­Ã‚ ­a Mrquez: Love in the Time of Cholera One Hundred Years of Solitude The Autumn of the Patriarch A Very Old Man with Enormous Wings The General in His Labyrinth and more found here.

Avoid Capital Offenses When Using Job Titles

Avoid Capital Offenses When Using Job Titles Avoid Capital Offenses When Using Job Titles Avoid Capital Offenses When Using Job Titles By Mark Nichol When it comes to mechanical aspects of writing, few details seem to trip writers up as much as capitalization: when to use uppercase letters, and when to use lowercase letters. Specific job titles preceding a person’s name are capitalized, but descriptions are not. For example, â€Å"Marketing Director John Doe† is correct, but â€Å"Marketing Chief John Doe† is not, unless â€Å"marketing chief† is John Doe’s actual title. After a name, titles are lowercase regardless of whether they are specific or general: â€Å"John Doe, marketing director at ABC Industries.† If you modify even a specific job title, such as noting that someone no longer holds a position, what appears to be specific becomes an apposition, part of a job description rather than a title: â€Å"former marketing director John Doe.† Some style guides disregard this last rule, and some publications choose to capitalize â€Å"president† when referring to the head of state even when the word appears in isolation from the title holder’s name, but this is an unnecessary nicety. Likewise, ordinary job titles in isolation are never capitalized. For example, the job title in â€Å"The park ranger asked for our permit† is a mere description, and needs no emphasis. Job titles are at times absurdly attenuated, and placing them before a person’s name can wear readers out. Confronted with a magnificent moniker like â€Å"Oracle Principal Product Manager for Windows Technologies John Doe,† relax the identification a bit: â€Å"John Doe, Oracle’s principal product manager for Windows technologies† (the proper name Windows remains capitalized even after the name), is a gentler approach. Capitalization of job titles and general descriptions alike is permitted in direct address when you are writing to someone (or transcribing a speech directed at them) and using the title or description in place of a name: â€Å"That’s an order, Sergeant†; â€Å"I’ll get right on it, Chief.† Capitalize formal and informal family-relationship labels, too, as in â€Å"If only Father were here† and â€Å"I’ll tell Mom!† but not in â€Å"Wait until your father gets home!† or â€Å"I saw your mom yesterday.† Terms of endearment aren’t capitalized, either: â€Å"I’ll get it, dear.† Most terms of respect are capitalized (â€Å"I object, Your Honor†), but â€Å"sir† or â€Å"ma’am†/†miss† are not (unless you are addressing a letter or an email, in which case you should write â€Å"Dear Sir† or the equivalent). The take-away about titles: Capitalization is seldom called for. Unless you’re using a person’s exact job title, and only the job title, immediately before that person’s name, chances are you shouldn’t capitalize it. Want to improve your English in five minutes a day? Get a subscription and start receiving our writing tips and exercises daily! Keep learning! Browse the Style category, check our popular posts, or choose a related post below:Comparative Forms of Adjectives40 Fish IdiomsThe "Pied" in The Pied Piper

Assignment Example | Topics and Well Written Essays - 1500 words - 12

Assignment Example The difference between the market value per share and the book value per share suggest that the stock at its current is bargain because the stocks are undervalued as the company is trading far much below its book value. The company therefore has a potential for future growth. The loan should be approved. Even though the company is performing below the industry average, it has a potential for future growth. The company has a relatively higher times interest earned hence is able to pay its interest expense with its operating income with ease. The company has a relatively higher working capital implying that it is relatively liquid hence can meet its short-term obligations as they become due with lots of ease. The company only needs to improve its efficiency in using shareholders money and assets for it to reach the level of other companies in the industry. The company’s current assets have increased from 39.92% last year to 45.61% this year. This implies an increase in liquidity of the firm hence ability to meet its short term debt obligations. However, the company’s current assets have increased as well but with a low margin compared to the increase in current liabilities. The company is relatively efficient in its operations. It has reduced its expenses thus increasing its operating income when compared to last year. This translates to the high net income compared to last year. The company has relatively steady overall results as it has relatively small changes in its financials. For instance, the net income has increased by only 1.29% from 4.04% in last year to 5.33% this year. The company therefore has a relatively stable

Should business take care of its superannuated employees Essay

Should business take care of its superannuated employees - Essay Example It is the obligation of the business management board to take care of the superannuated employees through adhering to the set restrictions. The essay below outlines the reasons why businesses should take care of the superannuated employees with a focus on the benefit to both the employee and business. Most employers and business management structures value their superannuation programs according to the assumed manner in which they are valued by the employees. The viability of the scheme should be ascertained formally through comprehensive research. This implies that most of these benefit programs do not satisfy the employee needs. Paying close attention to the improvement of the superannuated benefits will ensure that the benefits are aligned with what employees want and value. Catering for the welfare of the superannuated employees acts as an assurance to other employees that their future benefits are flexible enough to be useful even when outside the work environment (Billing et al, 2010). Superannuation plays a crucial role in the improvement of the retirement benefits. The change in superannuation programs has enabled employees to apply their superannuation benefits in paying off their mortgage and investing in shares. Focus on superannuated employees ensures that improvement of their welfare is maintained through the use resources from the fund. Superannuation is popular among the work force due to the compound interest accrued after a long working life. The business has an obligation of ensuring that the long-term accumulated benefits are paid during retirement. Taking care of superannuated employee ensures that their patience and willingness to get involved in the high-risk investment is rewarded. Employees should be guarded against losses in the case of business failure. Superannuated employees are the most vulnerable to losses in the event

the enforcement of EU law :: essays research papers

To answer this question I will firstly explain how EU law became incorporated within the member states I will then explain the various types of EU legislation's in circulation. This is important to define as the various types of methods will involve different enforcement procedures. Finally I will explain how EU law is enforced and the ways EU law will effect the member state and individual businesses. I will summarise my findings at the end of the essay, this will give details of all the key ideas I have ut across. The Schuman proposal began various European countries setting up the European Coal and Steal Community (ECSC), this was signed in 1951 by six countries. The countries that initially set up the ECSC were France, Germany, Italy, Luxembourg, Belgium and the Netherlands. The idea behind the ECSC was the first serious institutional committee in Europe and was the start of integration, the aim was to provide a common market of coal and steel trade. This meant that each of the states would be able to have access to the various qualities of coal and steel that the members had with no tariff of importing and exporting to the various countries. This let the countries concentrate on their more efficient areas leading to specialisation. The ECSC began the beginning of supranational power because the "High Authority could adopt binding decisions" (1) as elements of decision making were carried out by ECSC committees. A supranational power is where the member state has to abide by the de cisions made of the community, as they have power above the national level. When the EC makes a law it is up to the individual state to implement the legislation. An example of EU law which has been passed which has been adopted in the UK is that of the directive 75/117 which states that men and women should receive equal pay. The UK government adopted this directive with the 1975 Sex discrimination Act. There are a number of methods EU legislation is formed for instance regulations, directives and decisions are three different types of EU legislation. I am going to briefly explain these three as the way they will be enforced are different. Regulations have general application that means that all the member states have to adopt the regulation; the member state is expected to adopt the whole regulation. Regulations are directly applicable which means that the "individuals have rights that they can enforce in their own name through national courts"(2).

Bus Frequency Determination Using Passenger Count Data

Tmnspn. Rcs:A Vol. 18A. No. 516. pi. 439153. Printed m ths U. S. A. 1984 0191-2607’81 s3. @3+m Pcr&mon Rss L:d. BUS FREQUENCY DETERMINATION PASSENGER COUNT DATA Department USING of Civil Engineering, Transportation Research Institute, Tcchnion-Israel Technology, Haifa, Israel (Received 21 February 1983; in revised form 5 December 1983) Institute of Abstract-The importance of ridership information has led transit properties to increase the amount of manually collected data or alternatively to introduce automated surveillance techniques.Naturally, the bus operators are expected to gain useful information for operations planning by obtaining more accurate passenger counts. This paper describes and analyzes several appropriate data collection approaches for the bus operator in order to set the bus frequencies/headways efficiently. Four different methods are presented to derive the bus frequency: two are based on point check (maximum load) data and two propose the use of ride check (load profile) data.A ride check provides more complete information than a point check, but at a greater cost, and there is a question as to whether the additional information gained justifies the expense. Based on available old profiles, the four methods provide the bus scheduler with adequate guidance in selecting the type of data collection procedure. In addition, the scheduler can evaluate the minimum expected bus runs when the load standard is released and avoid overcrowding (in an average sense) at the same time.Alternative timetables are also investigated in conjunction with minimizing the required bus runs and number of buses for a single route. In this way, the derived headways can be analyzed within an acceptable range while considering the possible changes incurred indirectly to the fleet size. The integration between resource. saving and frequency determination procedures allows the scheduler’s performance to be improved. 1. IN7’RODUCI’ION AND ORJEC TIVES It is well known that transit demand varies systematically by season, day-of-the-week, time of day, location and direction of travel.However, the absence of accurate data on travel patterns at the route level has made it impossible to deploy transit resources to match these variations and thus to increase the efficiency of system operation. Accurate ridership information is needed for transit planning and scheduling and also to comply with external reporting requirements (e. g. Section 15 of the U. S. Urban Mass Transportation Act). Consequently, some transit operators have started to use automatic passenger counters while others are adding more checkers to collect the data manually.The primary objective of passenger counts, from the transit operator’s viewpoint, is to set vehicle frequencies/headways efficiently on each route. Other uses of ridership information are in revenue estimation and measurement of dynamic patronage trends. The topic addressed in this paper is two-fold. The first segment involves the setting of bus frequencies in order to maintain adequate service quality and minimize the number of buses required by the schedule. The second is an evaluation tool to efficiently allocate the cost for gathering appropriate passenger load data at the route level.It is common to almost all bus operators worldwide for load profile information along the entire iThis study was written while the author was in 1982 at the Transportation Systems Center (IX), Cambridge, Massachusetts, U. S. A. TSC Support is gratefully acknowledged. 439 length of the bus route (ride check) to be gathered annually or every few years. Usually the most recent passenger load information will be at one or more selected stops along the route where the bus carries its heaviest loads (point check).A ride check provides more complete information than a point check, but is more expensive because either additional checkers are needed to provide the required data or an automated surveillance system is used. There is a question as to whether the additional information gained justifies the expense. The objective of this study is to explore the way in which a bus operator can use the old profile to determine whether the ride check method or the point check method is appropriate in collecting the new data. This paper attempts to achieve this objective through three major parts.First, a brief review is introduced, and thereafter four different methods are presented to derive the bus frequency: two are based on point check (max load) data and two propose the use of ride check (load profile) data. Second, a preliminary criterion is established for determining the appropriateness of each of the data collection methods. Third, in order to complete the evaluation of the point check and ride check methods, altemative timetables are derived along with consideration of the minimum fleet size at the route level. 2. POINT CHECK (MAX LOAD) AND RIDE CHECK (LOAD PROFILE) ME THODS . 1 Review Generally, bus operators organize ride check surveys routinely at time intervals greater than or equal to one year and update their point check information 40 AVISHAI CEDER where P, is the average (over days) maximum number of passengers (max load) observed on-board in period j, c represents the capacity of a bus (number of seats plus the maximum allowable standees), and yj is the load factor during period j, 0 < ;: < 1. 0. For convenience, let us refer to the product y,c as d,, the desired occupancy on the bus at period j. The standard yi can be set so that 4. s equal to a desired fraction of the capacity (e. g. d, = number of seats). It is worth noting here that if P, is based on a series of measurements, one can take its variability into account. If the stochastic data allow, this can be done, for example, by replacing the average value in eqn (I) with P, + bZj where b is a predetermined constant and Z, is the standard deviation associated with P,. The max load d ata is usually collected by a trained observer who stands and counts at the bus stop believed to be located at the beginning of the max load section(s).This stop has usually been determined from old ride check data or from information given by a mobile supervisor. Often, these observers are told to count at only one stop during the whole day instead of moving to a different max load point at every period j. In this case the scheduling department identifies the point at which the bus is starting to carry a load associated with the heaviest daily load along the route. This method is referred to as Method I and can be written more explicitly as: $‘=? ,j=l,Z I ,†¦ , 9 several times a year for possible schedule revisions (see Vuchic, 1978).It is important to note that the frequency and the cross-sectional characteristics of these data collection procedures should be determined by the sampling techniques used. This statistical aspect, which is not part of this study, can be app roached through a variety of literature about sampling and is mentioned specifically in Attanucci Ed al. (198 I). Schedule revisions range from completely new timetables for new or revised routes to daily adjustments that accommodate changes in working hours and school dismissal times. The methods used by the bus operator to set headways are commonly based on existing service standards.These standards are based on two requirements: (i) adequate spaces will be provided to meet passenger demand, and (ii) the upper bound value is placed on the headways to assure a minimum frequency of service. The first requirement is appropriate for heavily traveled route hours (e. g. peak period), and the second for lightly traveled hours. The first requirement is usually met by a widely used peak loud fucfor method (point check), which is similar to the max load procedure-both are explained below. The second requirement is met by the policy headway which usually does not exceed 60 min and in some ca ses is restricted to under 30 min.Occasionally, a lower bound value is set on the headway by the bus operator, based on productivity or revenue/cost measures. There are also mathematical programming techniques to approach simultaneously the problems of route design and service frequency (see Lampkin and Saalmans, 1967 for an example). Recently such a technique has been adopted to find the appropriate headway so as to maximize the social benefit subject to the constraints on total subsidy, fleet size, and bus occupancy levels (Furth and Wilson, 1981). This model may be shown to be useful in policy analysis.However, these mathematical programming models have not been generally adopted by transit schedulers since they are not sensitive to a great variety of system specific operational constraints. For example, they cannot simultaneously determine even spaced headways and uneven spaced headways for situations of scheduling exceptions. 2. 2 MUX loud methodr The purpose of the basic stand ard used by bus schedulers is to ensure adequate space to accommodate the maximum number of on-board passengers along the entire route, for a given time period (e. g. one hour).Let the time period be denoted asj. Based on the peak load factor, the number of buses required for period j is: where P, is defined as the load in period j associated with the daily max load point. Additional notations are: max i Pii = f P,, and ES j-1 j-l P, = max P, LS where there are q considered time periods; S represents the set of all bus stops i, and P, is a defined statistical measure (simple average or perhaps with the standard deviation consideration) of the total number of passengers which are on-board all the buses departing stop i during period j.Table 1 displays the ride check information which will be used throughout the paper. This is actual data collected on one route in Jerusalem-route 27(A) of Egged (The Israel National Bus Carrier). In Table 1, the first and second columns are the distanc es (in kilometers) between each two adjacent bus stops and the stop name, respectively. The set of stops S includes 34 i’s excluding the last stop. The first two rows represent the time interval, j = 1,2,. . . , 14, where each period of one hour is associated with a given column. In the third row are the number of buses scheduled in each period.The fourth row Bus frequency determination using passenger 1. Initial data count A data 441 Table for bus No. 27 direction: 12 59 1. 75 75 20 . 5 75 76 5. 9. 93 99 (25 ,511 102 16. to2 (81) (02 (98 ‘08 206 108 19. ,,, 126 (80 (84 192 (92 132 14, (95 195 (55 196 162 19. (93 18. (93 132 159 I. 1 (47 138 (35 (28 I,7 ,,a t,. (3. ‘(1 I32 10. 9 ,,a 108 96 78 78 78 78 53 33 19 20 (2 ____ ____ 158 20. 208 215 220 252 268 259 28. 280 280 250 28. 295 295 29. 299 252 2. 9 235 236 228 22. 212 2,6 (80 l-72 (5. 452 ,. O tar (0. 72 40 ____ 180 223 225 239 2. 5 2. 5 2. 5 250 2. 8 2. 3 2. 2. 5 2. 5 235 240 2. 0 239 203 198 195 200 (98 190 ( 78 159 (53 I38 135 115 105 93 95 90 68 ____ 175 235 220 220 220 220 230 255 2. 0 295 3,s 320 320 320 3m 300 290 290 320 250 290 3t0 310 285 255 210 (90 195 (75 (55 (00 (35 90 20 ____ 239 266 255 270 266 263 259 253 29. 265 270 273 253 259 2. 9 239 228 23, 2,7 (93 $75 ,. , 151 1. 7 t. 0 ,,a 95 8. 60 49 . 9 . 9 32 ,I ____ 280 351 375 379 375 378 37, 36, 36. 399 37, 37, 35. 37, 357 3. 7 335 239 2. 5 210 196 199 192 165 133 102 77 ;; ii 50 10 i; 42 10 –__ 320 411 395 392 397 3,. 395 398 390 387 390 40, 398 403 403 39. 55 339 3. 7 29. 299 270 25. 256 2. 8 209 192 179 136 120 109 (28 (0, 37 ____ 275 4. 1 450 462 . 95 . ,7 455 465 477 495 . BO 47, 455 474 4,. .,, . 50 . 26 120 350 3. 5 336 339 336 303 25. 2. 9 225 (92 183 (68 ‘80 255 26, 25. 273 257 273 285 297 29, 306 32. 3,s 3,2 315 303 29. 2. 9 2. 0 23. 229 20, ,,. ,53 (38 II iii 51 ____ (05 235 295 308 315 3,9 325 329 325 3,s 31. 9 320 320 32. 9 325 335 338 3,9 2. 3 2. 3 239 220 213 200 170 (65 155 153 155 (43 130 129 (15 70 30 . ___ 90 (08 ,. I 14, 150 I. 7 I. 4 I. 7 f50 (50 1. 4 1. 7 153 159 (59 $55 1. 7 ,,, I,, 4 17 123 (1.Il. iO5 93 57 39 36 30 2, 2. I. 9 6 0 ____ 225 2. 9 2. 5 2. 5 2. 0 23. 23, 228 228 219 219 216 215 20. 198 (85 (7, 1,. 3,. ii9 96 90 8, 69 5, ,A ii ii 15 12 ,a 9 i 3 -___ 37 . 2 42 47 50 5, 5, 52 5, 52 50 50 5. 5. 52 . 9 . , 40. 35 32 28 2, 23 1, 15 12 9 8 4 2 2 2 I , ____ 2. 85 3159 3232 33,3 3399 3. 20 3. 85 3557 3597 3575 3696 3732 37,5 3,,9 359. 3610 350. 3092 3096 2950 2793 25,. 25. 3 2356 2170 ,725 ,673 1596 ,376 12,. (07. (02. 7. 3 356 – – – – represents the policy headway which is equal to 60 min, and the fifth row is the desired occupancy, 4.As can be seen, 4 = 65 has been assigned to peak hours and 4 = 47 (the total number of seats) assigned to off-peak hours. The last column in the table represents ? Pv where each entry in the table is Pu j=l (an average value across several checks). Thus, the daily max load point is the 12th stop with a to tal of 3732 passengers and P, in eqn (2) refers only to those entries in the 12th row. The second point check method is based on the max load observed in each time period. That is, This method is called Met/&Z. Table 2 lists the value of P. , and the values of Pi for allj based on the input data given in Table 1.The comparison between methods 1 and 2 and between the point check and ride check methods using more data sets is performed in a following section. 2. 3 Load profile methodr The data collected by ride check enables the scheduler to observe the load variability among the bus stops. Usually the distribution ,of loads will suggest possible improvements in route design. The most common operational strategy resulting from observ- ing the various loads is short turning (shortlining). A turnback point before the end of the route may be chosen, creating a new route overlapped by the existing route.Other route design related actions using the load data are route splitting and route s hortening. For the route design considerations, bus operators frequently use the histogram of the average load plotted with respect to each bus stop without relating the loads to the distance between the stops. The only concern of these operators is to identify a sharp increase or decrease in the average load for possible route design changes. This has been observed at SCRTD (Los Angeles), CTA (Chicago)–while using the EZDATA program provided by the company ATE, Egged (Israel), and other bus properties world-wide.A more appropriate way to plot the loads is to establish a passenger load profile. In this technique, the loads are plotted with respect to the distance traveled from the departure stop to the end of the route. It is also possible to replace the distance by the average running time, but in this case it is desirable for the running time to be characterized by low and persistent variations. Two examples of the load profile are given in Figs. 1 and ‘2, exhibiting the data of two time periods appearing in Table 1. Each asterisk in the figures represents five passengers.The area under the load profile curve is simply passenger-miles, or in this example, passenger-kilometers, both of which are AVISHAI CEDER Table 2. Output indication of variables used in methods 1 and 2 320 1259 1359 1459 ,559 284 389 . ,1 0 0. 0 0. 6 ‘†¦Ã¢â‚¬ ¦. *‘†¦ 50 100 150 2po .. *. **.. **†¦.. * †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 2. 1 2. 9 3. 2 3. 5 3. 9 4. t 4. 7 5. 3 5. 5 5. 9 9. 5 5. 7 7. 3 7. 7 9. I 8. 5 9. 1 9. 5 10. 0 10. 4 IO. 6 10. 9 ,,. I 11.. 11. 5 12. 1 ‘2. 5 13. 2 13. 9 I.. 1 14. 8 15. 0 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ ’ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦. †¦ Fig. 1. A load profile for one morning time period (8:00-8: 59) based on the data in Table 1. Bus frequency determination using passenger count data 443 NIJMSER PISSENGERS OF FOR INTERVAL ~500 TO 1559 DlSTlNcE (KY. 1 50 – NUMBEP PAssENGERI OF 200 250 300 ’ 350 400 450 500 I 100 150 L†¦Ã¢â‚¬ ¦.. 1†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ 1†¦Ã¢â‚¬ ¦.. 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†¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚ ¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã ¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. Fig. 2. A load profile for one afternoon time period (15:[email  protected]:59) based on the data in Table 1. measures of productivity.If a straight line is drawn across the load profile at the point where the number of passengers is equal to the observed average hourly max load, then the area below this line but above the load profile is a measure of the non-productive service. When method 2 is used to derive the headways, and dj is equal to the number of seats then this measure is the empty seat-miles (or empty seatkilometers). Figure 1 is characterized by a relatively large value of empty seat-kilometers per bus in comparison to Fig. 2. However, the additio nal information supplied by the load profile enables one to overcome such an undesirable characteristic.This can be done by introducing frequency determination methods which are based on passenger-miles rather than on a max load measure. The first load profile method considers a lower bound level on the frequency or an upper bound on the headway, given that the bus capacity constraint is held. Method 3 is: q? = max One way to look at method 3 is that the ratio A,/L of the load P, (regardless of its statistical definition) as opposed to the max load (P,) in method 2. Method 3 guarantees, on the average basis of P,, that the on-board passengers at the max load section will not experience crowding above the given bus capacity c.This method is appropriate for frequent cases in which the schedulers wish to know the number of bus runs they can expect to reduce by relaxing the desired occupancy standard, avoiding overcrowding at the same time. This allows them to handle the following: (i) demand changes without increasing the available number of buses; (ii) situations in which some buses are needed elsewhere (e. g. breakdown and maintenance problems, or emergencies); (iii) fewer drivers than usual (e. g. due to budget cut, or problems with the drivers’ union).On the other hand, method 3 can result in unpleasant travel for an extended distance in which the occupancy is above 4. To eliminate or to control this possible undesirable phenomenon, another method is introduced. Method 4 establishes a level of service consideration by restricting the total route distance having loads greater than the desired occupancy. Method 4 takes the explicit form: is an average representative A. P. -A-,1 dj. L c 1 [ [ 4. L’ Ai1 pj c where Ii is the distance between stop i and the next stop (i + l), Aj is the area in passenger-miles (km) under the load profile during time period j, and L is the route length.The other notations are previ )usly defined in eqns (l)-(3). 4? =max St. 1 Ii I jJj. L, *I) 444 AVISHAICEDER by time of day are same to that indicated in Table 2, and for all five sets the capacity is c = 80 passengers. In method 4 based on eqn (5), three values are assigned to /I, for all j’s: 0. 1, 0. 2 and 0. 3. That is, 10, 20 or 30% of the route length is allowed to have an observed occupancy, P, exceeding the desired one, 4. The results for route 27(A) appear in Table 3. The headway results of the four methods are compared graphically in Fig. 3 where the results of method 4 are for only the 20% limit case (8, = 0. ). Similarly to Fig. 3, the results of the remaining four data sets are displayed only in the computer generated graphical form in Figs. 4-7. . These illustrations are used for further analysis of the results. The first comparison can be made between method 1 and method 2 for the point check decision. Obviously, it is less costly and more convenient to retain an observer at one bus stop during the entire working day, than to a ssign the same observer or others to a different stop at every period j. This candidate bus stop is the one characteiized by P, (see eqn (2)).The comparison between the two methods is performed by the ,$ test between two sets of actual observations-P. , vs P, for each data set (see Ceder and Dressier, 1980). The results are as follows: where I, = {i: (P,,/F,) > d,} or 4 is the set of all stops i in time period j such that the load Pq exceeds the quantity of 4 times the number of buses determined iteratively by F,, and pj is the allowable portion of the route length at period j in which Pti can exceed the product (4)()(d,). The other notations in eqn (5) are previously defined. By controlling the parameter /Ii it is possible to establish a level of service criterion.Note that for /I, = 0, /I, = 1. 0 method 4 converges to method 2 and method 3, respectively. 2. 4 Results of actual data and comparison A pL/l program has been written for all the four methods. This program, in addition t o calculating the bus frequencies, determines the associated integer headway (in minutes) by simply dividing the length (in minutes) of a considered time period j by 4. , and rounding it to the nearest integer. The headway information is essential for the timetable preparation, as is explained in the next section. The input data presented in Table I and also the data taken from four more routes have been run by the program.The additional data are four Egged routes: 2(A), 2(B), 12(A), and 39(A)—all from Jerusalem. Their policy headway and desired occupancy Route (Direction) 27(A) 2(A) 2(B) d. f. 13 16 18 14 16 X2 63. 24 14. 59 58. 51 492. 82 117. 82 null hypothesis about equal methods (at the 5% significance level) reject don’t reject reject reject reject I&4) 39(A) Bus frequency determination using passenger count data 445 BUS NO. 27 , DIRECTION A LEGEND o – METHOD + – METHOD . – METHOD 1 2 3 L (BY2OP a – METHOD 0’. 7:oO . . 9 . . oo 11-00 . . TIME 13. 00 OF DAY ’ * 15. 00 ’ . 1Ãâ€"00 1 . 19:oo 21 00 g Fig. . Comparison of headway results for route 27(A). Consequently, only in route 2(A) can the daily max load point replace the hourly max load point. The PL/l program provides this comparison. The graphical comparison between the headways in Figs. 3-7 shows the expected result: method 2 always gives the minimum headways while method 3 results in the highest headways (except in 2 out of 82 time periods). Another characteristic of the headways, exhibited particularly in Figs. 4 and 5, is that the given policy headway (60min) is used during off-peak hours. A point worth mentioning is that the esults might be sensitive to the length of the time intervalj and that different time intervals may be used for peak and off-peak hours. Further analysis and comparison of the results are addressed in the following two sections. 3. A PRELIMINARY CRITERION IN DETERMINING FURTHER DATA COLLECTION METHODS In this sec tion an assumption is tested that particular load profile characteristics suggest the data collection method to be used. The basic idea is to BUS NO. 2 , DIRECTION â€Å"A† . – METHOD 3 6, 04.. . . . . . . I a. . -METHOD LCBY20%1 * ’ . ’ 6. 00 800 10 00 12. 00 TIME OF 14. 00 DAY 16:OO 16 00 20. 00 2:oo Fig. 4. Comparison of headway results for route 2(A). 446 AVISHAICEDER BUS NO. 2 , DIRECTION ‘B’ . 6 _ METHOD L CBY20T. l 01 . 5:oo . . 7 00 . 9 00 * 1100 . TIME . 13. 00 _ 15 00 OF DAY .. , 17 00 . 19 00 . . 21 00 23 00 Fig. 5. Comparison of headway results for route 2(B). provide the bus operator with adequate preliminary guidance in selecting the type of method based on old load profiles. The assumption to be investigated is that a relatively flat profile suggests the use of a point check procedure (method 1 or 2) whereas a ride check procedure (method 3 or 4) would be appropriate otherwise.One property of the load profile is its density, p. This is the observed measure of total passenger-miles (total ridership over the route) divided by the product of the length of the route and its maximum load (passenger-miles which would be observed if the max load existed across all the stops). Thus, the load profile density for hour j, pj, is P’=e. The load profile density is used to examine the profile characteristics. High values of p indicate a relatively flat profile, whereas low values of p indicate a significant load variability among the bus stops. A BUS 60 NO. 39 , DIRECTION â€Å"A† LEGEND % $ s 2 L2. 36. METHOD ‘ (BY ZCr%l = 30. p' I 9 i P 12. 6. 24. 18. 0. 1 6 00 . a 00 . 10 00 . 12. 00 TIME OF woo DAY 16 00 18. 00 20 00 2200 Fig. 6. Comparison of headway results for route 12(A). Bus frequency determination using passenger count data 447 BUS NO. 12 , DIRECTION ‘A† LEGEND o _ METHOD + . METHOD METHOD 1 ;/ 2 3 : ,’ / ;* I 8 ’ METHOD L (ByZoZl 0’ 500 I – I 1 7 . oo 9:oo 11:oo I . TpF ;nY15:00 ‘. 17:oo ‘ 19:oo ‘ ‘ Fig. 7. Comparison of headway results for route 39(A). 3. 1 Mathematical analysis One way to approximate the observed shapes of profile curves is by using a mathematical model.The lognormal model has been selected for this purpose since it provides a family of curves which can be controlled by varying the parameters p and u. The lognormal model takes the form: f(x) =. & The equation satisfying (df(x)/dx) = 0, is e-oDX-*~/262; x ; 0. the optimum (7) conditions, x,=d-â€Å"= (8) This continuous model can only approximate some of the observed load profiles since it has only one peak and represents monotonically increasing and decreasing functions before and after this peak, respectively. Nonetheless, this model is useful in observing some general differences between the ride check and point check methods.In order to be able to compare the methods,f(x) is used as a normalized load (the load divided by the max l oad) and x is used as a normalized distance (the distance from the departure stop divided by the length of the route). At a given time interval of one hour, j, the considered max load is Pi = 650 passengers. Given that dj = 65 and that c = 100, the determined frequency and headway for both methods 1 and 2 are 4 = 10 and Hj = 6. By applying this information to methods 3 and 4, using a variety of lognormal curves, one obtains the frequencies and headways shown in Table 4.The results in this table are aranged in increasing order of density. For method 3, the capacity constraint determines the values of F and H up to an including p = 0. 64 and up to different p values (if any) for method 4. Examples of the lognormal normalized curves are shown in the computer generated Figs. 8 and 9 for two p and variety of p values. Note that the relative location of the max load point can be found by eqn (8). From Table 4 it appears that for method 3 the ride check (load profile) data results in the s ame rounded headway as for the point check (max load) data for p 2 a where 0. 4 ; a 5 0. 87. For method 4 the ride check and point check information tend to yield the same headways for p 2 ai where i = 1,2,3, for the 10, 20 and 30% cases, respectively, and 0. 34 ; a, I 0. 43, 0. 50 ; a2 I 0. 56, and 0. 64 ; a, 50. 68. 3. 2 Observed densities and discussion The five data sets mentioned in the previous section were also subject to the load profile density examination. The pi values for each considered hour j, based on eqn (6), were calculated and are shown in Table 5. For example, in Fig. 0, which is part of the PL/l program output, one can visually compare the load profiles associated with the highest and the lowest p value of data collected on route 39(A). As can be seen from Table 5, none of the p values exceed 0. 8. This suggests that one cannot reach, by calculation, same headways for method 3 and method 2. Figures 3-7 reveal that the determined headways of method 3 are always gr eater than those of method 2 excluding the cases of policy headway. However, no clear cut conclusion can be drawn when trying to associate the p values in Table 5 with those 448 Table 4. Frequencies (F) and headways log-normalAVISHAI CEDER (H) for different load profile configurations (derived from the model) using methods 3 and 4’ Method 3 profi 1e density T by 10% H F 7. 60 H Method 4 20% H 9 9 9 9 9 8 7 : 8 -%6 6 6 6 6 6 6 6 6 6 1 by by P F F F 30% H 9 9 9 9 9 9 0. 18 0. 25 0. 27 0. 32 0. 34 0. 43 E 0:48 0. 50 0. 56 0. 57 0. 59 0. 62 0. 64 0. 68 0. 75 0. 76 0. 78 0. 84 0. 87 *For Note: 6. 50 6. 50 6. 50 6:50 6. 50 6. 50 6. 50 6. 50 6. 50 6. 50 6. 50 6. 50 6. 50 6. 77 7. 46 7. 63 7. 77 8. 41 8. 72 9 9 9 9 E% 9’ z 9 9 9 9 9 9 9 : 7 7 -4. 8. 46 6. 50 8. 36 7. 55 9. 00 7 9 7 7 -i5: 6 6 6 6 6 6 6 6 6 6 6 6 6 6. 50 6. 50 6. 50 6. 50 6. 50 7. 05 8:05 E 7. 5 x 9:31 8. 85 9. 04 9. 42 9. 36 9. 68 9. 87 9. 76 9. 92 6. 50 6. 50 6. 50 6. 50 6. 50 6. 50 z! 9:45 9. 05 9. 92 9. 76 9. 81 9. 65 9. 79 9. 87 9. 86 9. 93 9. 97 9. 96 9. 97 constraint ?E 8’ 6:50 9 6. 50 9 9. 27 6 8. 16 7 8. 46 7 7. 80 7 8. 19 7 8. 72 -b 8. 76 6 9. 23 6 9. 72 6 9. 46 6 9. 82 6 Methods 1 and 2: Uhenever F-10. H=6 where d F=6. 50, H=9 the capacity = 65, c-100. is met. in Table 4 regarding the comparison between methods 4 and 2. Figures 3-7 clarify this by illustrating the results of method 4 for the 20% case. The matchings (same headways for methods 2 and 4) across all the five data sets range between p = 0. 38 (route 2(B), for the hour 22:00-22: 59) and p = 0. 744 (route 39(A), for the hour 16:00-l6:59). On the other hand, the non-matching cases range between p = 0. 457 (route 2(B), for the hour 8:00-8:59) and p = 0. 777 (route 12(A), for the hour 15:00-15:59). Consequently, when applying method 4 to the observed load profiles, the results of the lognormal model cannot be explicitly used and an actual comparison between methods 2 and 4 should be performed. In practice, the bus operator wishes to save bus runs and eventually to be able to perform the matching between demand and supply with fewer buses.As is shown in the next section, different headway values do not necessarily save bus runs or reduce the required fleet size. However, the analysis made about the profile density measure can be used by the bus operator as a preliminary check before entering a more comprehensive analysis. The following are practical observations: (i) for densities below 0. 5, p-o 66 OK 0 1 .2 .3 Fig. 8. Four approximated load profiles based on the log-normal model (a = 1. 00). Bus frequency determination using passenger count data Fig. 9. Four approximated load profiles based on the log-normal model (u = 1. 0). savings are likely to result by gathering the load profile information and using either method 3 or 4 (alternatively for such low p values, the profile can be examined for short turn strategies); (ii) for densities between 0. 5 and 0. 85, it is recommended that an actu al comparison be made between the point check and ride check methods-along with further saving considerations (see next section); and (iii) for densities above 0. 85 it is likely that the majority of the required information for the headway calculation can be obtained from a point check procedure (either method 1 or 2). . ALTERNATIVE The TIMETABLES AND FLEET SIZE possible to initiate the task of scheduling buses and crews to the previously determined trips. Naturally, the bus operator wishes to utilize his resources more efficiently by minimizing the number of required buses and the cost of the crew. To accomplish this, the scheduler examines different timetables during the bus and crew assignment processes. This is done by shifting the departure times or by reducing the number of departures without referring usually to the initial source of passenger loads-the profile.Therefore, it is desirable to extend the analysis deriving appropriate headways, to an evaluation of timetables in conjunction with the required resources. 4. 1 Construction of timetables The number of bus runs determined by the timetable and eventually the number of buses required, is sensitive to the procedure used by the scheduler to CONSIDERATION AT THE ROUTE LEVEL products of the derived headways are the timetables for the public, the bus drivers and supervisors. Once the timetables are constructed, it is Table 5. Load profile densities @) for five data sets I 500. ! :00 7:oo 8:00 9:oo lo:oo Time Interval : – 6:59 – 7:59 – 8:59 – 9:59 – 10:59 – 559 : Route Z(A) v-e 0. 489 Route Z(B) Route 12(A) ll:oo 12:oo 13:oo 14:oo 15:oo 16:00 17:oo l 19:oo 20:oo 21:oo 22:oo 23:00 – 11:59 12:59 13:59 14:59 15:59 16:59 17:59 18:59 19:59 20:59 21:59 22:59 23:59 0. 668 0. 557 0. 687 0. 548 0. 687 0. 477 0. 694 0. 652 0. 699 0. 606 0. 632 0. 73j 0. 610 0. 524 0. 588 0. 543 ___ 0. 524 0;702 0. 752 0. 457 0. 586 0. 592 0. 647 0. 620 0. 679 0. 764 0. 662 0. 717 0 . 722 0. 618 0. 673 0. 633 0. 588 0. 538 0. 546 0. 661 0. 705 0. 625 0. 731 0. 637 0. 589 0. 680 0. 39 0. 740 0. 712 0. 777 0. 640 0. 565 0. 650 0. 509 –a _-_ -se -me ___ –0. 563 0. 567 0. 715 0. 765 0. 717 0. 672 0. 636 0. 733 0. 723 0. 641 0. 712 0. 639 0. 576 0. 593 ___ _____ Route 27(A) _-_ 0. 651 0. 561 0. 589 0. 674 0. 594 0. 559 0. 619 0. 644 0. 599 0. 691 0. 744 0. 626 0. 657 0. 544 0. 686 0. 610 0. 577 _-_ Route 39(A) 0. 0 0. 3 0. 4 0. 7 1. 1 1. 3 1. 7 2. 3 ?. I 2. 7 3. 1 3. 5 3. 9 4. 4 4. 9 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. 5. 6 5. 1 ‘6. 2 6. 4 6. 7 7. 1 7. 5 7. 8 8. 2 8. 4 8. 6 9. 0 9. 1 9. 2 9. 5 9. 6 †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. .; †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦ †¦ .* .. ** †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦.. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦ †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. †¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦Ã¢â‚¬ ¦. Fig. 10. Two load profiles of route 39(A) with the highest density @ = 0. 744) on the left and the lowest density @ = 0. 544) on the right. construct the departure times.Some bus operators routinely round the frequency 5 to the next highest integer and then calculate the appropriate headways for the considered time period. By doing so, they increase the number of daily departures beyond what is needed to appropriately match the demand with the supply. Such a procedure may result in nonproductive runs (many empty seat-miles). For example, in Table 3 the number of daily required departures, F 4, is 77. 01, 55. 64 and 73. 24 for methods j=l 2,3 and 4 (20% case), respectively. When the quantity F, is â€Å"rounded up,† one obtains respectively: 85, 65 and 80 daily departures for these three methods.Obviously, by rounding k; to the next highest integer, the sched uler increases the level of passenger comfort but, at the same time, causes an unnecessary operating cost. However, in some cases the â€Å"round up† procedure may be justified if the scheduler uses the Pq quantity as an average load whereas the variance of the load is high. In this case (provided that additional runs are made by rounding up Fj), the possible overcrowding situations may be reduced as opposed to increasing the average empty seat-miles. Nonetheless, to overcome the problem of highly variable oads, one can use a statistical load measure which considers its variance as an input to a frequency method (see remarks in eqn (1)). Another characteristic of the existing timetables is the repetition of departure times, usually every hour (see Vuchic, 1978). These easy-to-memorize departure times are based on the â€Å"clock headways†: 6, 7. 5, 10, 12, 15, 20, 30, 40, 45 and 60 min. Generally, headways less or equal to 5 minutes are not considered by schedulers to influence the timing of passenger arrivals to a bus stop. The clock headway is obtained by rounding the derived headway down to the nearest of the above â€Å"clock† values.Consequently, and similar to the â€Å"round up† frequencies, the clock headways require a higher number of departures than what is actually necessary to meet the demand. In order to keep the total daily number of departures as close as possible to the sum of the obtained Fj’s by the four methods, the derived headways in Table 3 and Figs. 3-7 are simply based on the â€Å"round to the nearest integer† procedure. Note that for a high frequency value it may turn out that rounding Fj result in fewer departures than rounding the derived headway. However, for high frequencies, the timetable is not required.Also, if 5 is rounded first it is necessary to perform a second rounding on its associated headway (since timetables are built by headways-not frequencies). This by itself may ultimately decrease the accuracy of matching the demand with the number of departures. An attempt is made in Table 6 to construct six daily timetables for methods 2,4 and 3 using both the derived and the clock headways based on the information in Table 3. The only incompatability is that Bus frequency determination using passenger count data 451 Table 6. Various timetables for bus 27(A) based on methods used and considered headways Y I9 ii:01 :3a :oa :57 :15 a:17 :22 :3a :29 :59 :36 9:14 :43 ~24 :50 :34 :57 :44 14:04 :54 :I1 10:04 :1s :15 :25 :26 :32 :37 :39 :4a ~46 :59 :53 11:09 15:OO :ia :08 ~27 :I6 ~24 :36 :45 :32 :54 :40 12:03 :4a :13 :56 :23 16:06 :33 :la :43 :30 :si :i5 17:04 :30 :12 :45 :20 a:00 :2a :20 :36 :40 :44 9:oo :52 :lO ia:m :20 :la :30 :36 :40 :54 :50 19:oa 1o:oo :19 :lO :30 :20 :41 :30 :52 :4o 20:24 :50 21:17 11:OO :07. 5 :I5 :22. 5 :30 :37. 5 :45 :52. 5 12:oa :lO :30 :40 :50 13:oo :06 :12 :la ~24 :30 :36 :42 :4a :54 14:oo :06 :12 :la ~24 :30 :36 ~42 :4a :54 1s:oo :07. 5 :15 z 22. :30 :I5 :52. 5 16:Ml :12 ~24 :36 :4a 17:oo :07. 5 :15 :22. 5 :30 :37. 5 :45 :52. 5 la:00 :15 :20 :ll :40 :19 a:03 :27 :29 :35 :55 :43 9:13 :5i :23 :59 :33 14:06 :43 :13 :53 :20 10:03 ~27 :14 :34 :25 :41 :36 :4a :47 :55 :5a 15:oz ii:08 :lO :17 ii; :26 :34 :3s :44 ~42 I :53 :5Ll ! lZ:Oi :G :12 16:oa :21 :34 :34 :44 :47 :12:54 17:W :la ~27 :36 :45 :54 ia:oa ~27 ~46 :59 19:ll :23 :35 :47 2o:zo 21:15 ! uer~ved LIOC): Headway 00 12~30 16 00 7 :12 :23 ~24 :46 :36 a:lo :4a :36 17:w :55 :07. 5 9:oa I:00 :22. s :I5 :21 :10 :30 :34 :20 :37. 5 :22. 5 :46 :30 :30 :45 :37. 1o:oo :40 :52. 5 :15 :45 :50 14:oa :30 :52. 5 I:00 :06 :45 :10 :12 la:00 1l:OO :15 :20 :18 :I2 :30 :30 ~24 :45 :24 :40 :30 :36 19:oo :50 :36 :4a 1:oo ~42 :12 ~24 12:oa :07. 5 ~48 :15 :lS :54 :36 :30 :40 :22. 5 15:oo :45 :30 :07. 5 2o:oo 13:oo :45 ~27. 5 :15 :ll :45 :22. 5 21:30 :52. 5 :30 2:oo z37. 5 :10 :45 :44 :20 :52. 5 20’) i : . I :oo ’ I :lO :2o :Jo :40 :50 2o:oo :45 21:30 ! : z24 i ( i:: ; i ~55 uETmb3 He4dw4y , Clock HeadMy 14:os 7:oo 13:so 19:5 :20 14:oo :4 :14 :40 :07. 5 2o:a :23 :I5 a:00 21:c :32 :20 :22. 5 :41 :40 :30 :50 9:oo :37. 5 :59 :12 :45 15:08 :I4 :52. :ia 15:oo ~36 :2a :4a :10 :3fl 1o:w :20 :4a :15 :30 :5a :30 :40 16:lO :45 :50 :25 11:OO 16:OO :40 :12 :15 :55 ~24 :30 11:08 :36 :45 :20 :48 17:oo :32 . 44 12:oo :12 I56 :15 :I2 :30 :36 la: 16 :44 :45 :48 19:07 13:oo 18:OO :26 :lO :20 :20 :40 :45 :30 20:23 19:oo 21~23 :40 :15 I 1 the clock headway technique includes a value of 7. 5 minutes whereas the derived headways do not allow non-integers. The transition between the hourly periods for the derived headway is based on a smoothing rule that use the rounded down average headway whenever a transition from one hour to another occurs.For example, in method 2 the transition between the departures 8: 59 and 9: 14 is based on rounding down the average headway of 21 and 1Omin. A point worth mentioning here is that the schedulers often have the knowledge of different load patte rns during one period j, e. g. more loads in the first half hour than in the second. In this case they can request splitting or changing the time period j for further data collection. Also, they can insert more departures in the heavy-load interval than in the remaining interval, while ensuring the approximate total of Fj departures.Further consideration about creating timetables appears in a report by Ceder (1983). This includes development of methods to construct timetables with even headways and timetables with even (average) loads on individual buses while the headways are unevenly spaced. 4. 2 Single-route fleet size examination Within a large-scale bus system, buses are often shifted from one route to another (interlining) and they frequently perform deadheading trips in order to operate a given timetable with the minimum required buses.It is desirable to analyze the procedures to construct timetables and scheduling buses to trips simultaneously. However, due to the complexity of this analysis, these two procedures are treated separately. Therefore, in a bus system with interlining routes, the alternative timetables can be evaluated on the basis of the total number of required departures. This can serve as an indicator for the number of buses required, but without inserting each alternative timetable to the scheduling procedure, it will be difficult to predict the effect on the fleet size.One fleet size test that can be performed is based on the assumption that interlinings and deadheading trips are not allowed and that each route operates separately. In this case, given the mean round trip time, the minimum fleet size for that route can be found similar to the formula derived by Salzbom (1972). Let T be the round trip time including the layover and turn around time and that departures occur at discrete time points: t,, t2, r,, . . . , t,.Also, let N, be the number of departures between and including the two departure points t, and t, such that three con ditions (i) are fulfilled: t, ; tr, (ii) t, – tr I T and (iii) t,+, – t, ; T. Given that if t, = t, then the first tk, k = 1,2,. . . , n to agree with the first two conditions is t,. the minimum single-route fleet size, N,,,, is: Nmi,=max k i k=l Nk Following Salzborn arguments, eqn (9) simply means that N,, is the largest number of buses departing in any time interval of length T. This result can