Análisis del comportamiento de los viajeros del transporte interurbano en la isla de Gran Canaria

Máster Universitario en Sistemas Inteligentes y Aplicaciones Numéricas en Ingeniería (SIANI)

Aplicación de nuevas tecnologías en los sistemas de alumbrado

A medida que transcurre el tiempo la sociedad evoluciona, las ciudades crecen, se modernizan, mejoran su infraestructura y se ofrecen más y mejores servicios a sus ciudadanos. Esto ha hecho que durante muchos años las ciudades se hayan desarrollado sin pensar en lo que vendrá más adelante, contaminando el medio ambiente y consumiendo mucha energía y de forma ineficiente. Ante esta situación, y gracias a las innovaciones tecnológicas en materia de comunicaciones, se están adoptando medidas para dirigir la evolución de las ciudades hacia un modelo de ciudad inteligente y sostenible. Las redes de comunicaciones constituyen uno de los pilares sobre los que se asienta la sociedad, que se encuentra siempre en contacto con su entorno. Cada vez más, se tiene una mayor necesidad de conocer lo que ocurre en el entorno en tiempo real solicitando información climatológica en una determinada ubicación, permitiendo conocer el estado del tráfico para elegir la ruta hacia el trabajo, saber el tiempo que tardará el autobús en llegar a la parada, etc. Como éstos, se podrían citar muchos más ejemplos de necesidades y servicios que demandan hoy día la sociedad y que, seguramente, nadie pensaba que las iba a necesitar hace unos años. Muchos de estos servicios en tiempo real se consiguen gracias a las redes de sensores inalámbricas. Consiste en desplegar una serie de diminutos sensores en una zona determinada con el objetivo de recoger la información del medio, procesarla y modelarla para que esté disponible para los usuarios. Observando la tendencia seguida por las Tecnologías de la Información y de las Comunicaciones (TIC) se puede constatar una continua evolución hacia los dispositivos embedidos, de cada vez más pequeño tamaño y menor consumo y, al mismo tiempo, con mayor capacidad de proceso y memoria y facilidad para las comunicaciones. Siguiendo esta línea, se está construyendo la ciudad inteligente con capacidad para pensar y tomar decisiones, pero hay que dotarla de cierto grado de eficiencia. Se trata de aprovechar los recursos de la naturaleza para crear fuentes de energías limpias e ilimitadas. Empleando las tecnologías oportunas para transformar, por ejemplo, la energía del Sol o la energía del viento en electricidad, se puede alcanzar el modelo de ciudad que se pretende. ABSTRACT. As time passes society evolves, cities grow, modernize, improve their infrastructure and offer more and better services to their citizens. This has made for many years cities have developed without thinking about what will come later , polluting the environment and high energy consuming and inefficient . Given this situation, and thanks to the Technological innovations in communications, is being taken to direct the evolution of cities towards a smart city model sustainable. Communication networks are one of the pillars on which society rests, which is always in contact with their environment. Increasingly, there is a greater need to know what happens in the real-time environment requesting weather information in a certain location , allowing know the traffic to choose the route to work , namely the time take the bus to get to the bus stop, etc. . As these, you could cite many more Examples of needs and services that society demands today and, surely, no one thought that was going to need a few years ago. Many of these real-time services are achieved through networks wireless sensors. Is to deploy a series of sensors in a tiny given area in order to collect information from the environment, process and shape it to make it available to users. Observing the trend followed by the Information Technology and Communications (ICT ) can finding an evolving toward embeded devices of increasingly small size and lower power consumption and at the same time, higher capacity process and memory ease communications. Following this line, is under construction with capacity smart city to think and make decisions, but you have to give it some degree of efficiency. It seeks to harness the resources of nature to create clean energy sources and unlimited. Using appropriate technologies to transform, for example, energy from the sun or wind energy into electricity, it can achieve the model city intended.

50 Years Ago We Marched: What began on the grounds of Lincoln University, ended on the steps of the Alabama State Capitol

LINCOLN UNIVERSITY - On March 25, 1965, a bus loaded with Lincoln University students and staff arrived in Montgomery, Ala. to join the Selma march for racial and voting equality. Although the Civil Rights Act of 1964 was in force, African-Americans continued to feel the effects of segregation. The 1960s was a decade of social unrest and change. In the Deep South, specifically Alabama, racial segregation was a cultural norm resistant to change. Governor George Wallace never concealed his personal viewpoints and political stance of the white majority, declaring “Segregation now, segregation tomorrow, segregation forever.” The march was aimed at obtaining African-Americans their constitutionally protected right to vote. However, Alabama’s deep-rooted culture of racial bias began to be challenged by a shift in American attitudes towards equality. Both black and whites wanted to end discrimination by using passive resistance, a movement utilized by Dr. Martin Luther King Jr. That passive resistance was often met with violence, sometimes at the hands of law enforcement and local citizens. The Selma to Montgomery march was a result of a protest for voting equality. The Student Nonviolent Coordinating Committee (SNCC) and the Southern Christian Leadership Counsel (SCLC) among other students marched along the streets to bring awareness to the voter registration campaign, which was organized to end discrimination in voting based on race. Violent acts of police officers and others were some of the everyday challenges protesters were facing. Forty-one participants from Lincoln University arrived in Montgomery to take part in the 1965 march for equality. Students from Lincoln University’s Journalism 383 class spent part of their 2015 spring semester researching the historical event. Here are their stories: Peter Kellogg “We’ve been watching the television, reading about it in the newspapers,” said Peter Kellogg during a February 2015 telephone interview. “Everyone knew the civil rights movement was going on, and it was important that we give him (Robert Newton) some assistance … and Newton said we needed to get involve and do something,” Kellogg, a lecturer in the 1960s at Lincoln University, discussed how the bus trip originated. “That’s why the bus happened,” Kellogg said. “Because of what he (Newton) did - that’s why Lincoln students went and participated.” “People were excited and the people along the sidewalk were supportive,” Kellogg said. However, the mood flipped from excited to scared and feeling intimidated. “It seems though every office building there was a guy in a blue uniform with binoculars standing in the crowd with troops and police. And if looks could kill me, we could have all been dead.” He says the hatred and intimidation was intense. Kellogg, being white, was an immediate target among many white people. He didn’t realize how dangerous the event in Alabama was until he and the others in the bus heard about the death of Viola Liuzzo. The married mother of five from Detroit was shot and killed by members of the Ku Klux Klan while shuttling activists to the Montgomery airport. “We found out about her death on the ride back,” Kellogg recalled. “Because it was a loss of life, and it shows the violence … we could have been exposed to that danger!” After returning to LU, Kellogg’s outlook on life took a dramatic turn. Kellogg noted King’s belief that a person should be willing to die for important causes. “The idea is that life is about something larger and more important than your own immediate gratification, and career success or personal achievements,” Kellogg said. “The civil rights movement … it made me, it made my life more significant because it was about something important.” The civil rights movement influenced Kellogg to change his career path and to become a black history lecturer. Until this day, he has no regrets and believes that his choices made him as a better individual. The bus ride to Alabama, he says, began with the actions of just one student. Robert Newton Robert Newton was the initiator, recruiter and leader of the Lincoln University movement to join Dr. Martin Luther King’s march in Selma. “In the 60s much of the civil rights activists came out of college,” said Newton during a recent phone interview. Many of the events that involved segregation compelled college students to fight for equality. “We had selected boycotts of merchants, when blacks were not allowed to try on clothes,” Newton said. “You could buy clothes at department stores, but no blacks could work at the department stores as sales people. If you bought clothes there you couldn’t try them on, you had to buy them first and take them home and try them on.” Newton said the students risked their lives to be a part of history and influence change. He not only recognized the historic event of his fellow Lincolnites, but also recognized other college students and historical black colleges and universities who played a vital role in history. “You had the S.N.C.C organization, in terms of voting rights and other things, including a lot of participation and working off the bureau,” Newton said. Other schools and places such as UNT, Greenville and Howard University and other historically black schools had groups that came out as leaders. Newton believes that much has changed from 50 years ago. “I think we’ve certainly come a long way from what I’ve seen from the standpoint of growing up outside of Birmingham, Alabama,” Newton said. He believes that college campuses today are more organized in their approach to social causes. “The campus appears to be some more integrated amongst students in terms of organizations and friendships.” Barbara Flint Dr. Barbara Flint grew up in the southern part of Arkansas and came to Lincoln University in 1961. She describes her experience at Lincoln as “being at Lincoln when the world was changing.“ She was an active member of Lincoln’s History Club, which focused on current events and issues and influenced her decision to join the Selma march. “The first idea was to raise some money and then we started talking about ‘why can’t we go?’ I very much wanted to be a living witness in history.” Reflecting on the march and journey to Montgomery, Flint describes it as being filled with tension. “We were very conscious of the fact that once we got on the road past Tennessee we didn’t know what was going to happen,” said Flint during a February 2015 phone interview. “Many of the students had not been beyond Missouri, so they didn’t have that sense of what happens in the South. Having lived there you knew the balance as well as what is likely to happen and what is not likely to happen. As my father use to say, ‘you have to know how to stay on that line of balance.’” Upon arriving in Alabama she remembers the feeling of excitement and relief from everyone on the bus. “We were tired and very happy to be there and we were trying to figure out where we were going to join and get into the march,” Flint said. “There were so many people coming in and then we were also trying to stay together; that was one of the things that really stuck out for me, not just for us but the people who were coming in. You didn’t want to lose sight of the people you came with.” Flint says she was keenly aware of her surroundings. For her, it was more than just marching forward. “I can still hear those helicopters now,” Flint recalled. “Every time the helicopters would come over the sound would make people jump and look up - I think that demonstrated the extent of the tenseness that was there at the time because the helicopters kept coming over every few minutes.” She said that the marchers sang “we are not afraid,” but that fear remained with every step. “Just having been there and being a witness and marching you realize that I’m one of those drops that’s going to make up this flood and with this flood things will move,” said Flint. As a student at Lincoln in 1965, Flint says the Selma experience undoubtedly changed her life. “You can’t expect to do exactly what you came to Lincoln to do,” Flint says. “That march - along with all the other marchers and the action that was taking place - directly changed the paths that I and many other people at Lincoln would take.” She says current students and new generations need to reflect on their personal role in society. “Decide what needs to be done and ask yourself ‘how can I best contribute to it?’” Flint said. She notes technology and social media can be used to reach audiences in ways unavailable to her generation in 1965. “So you don’t always have to wait for someone else to step out there and say ‘let’s march,’ you can express your vision and your views and you have the means to do so (so) others can follow you. Jaci Newsom Jaci Newsom came to Lincoln in 1965 from Atlanta. She came to Lincoln to major in sociology and being in Jefferson City was largely different from what she had grown up with. “To be able to come into a restaurant, sit down and be served a nice meal was eye-opening to me,” said Newsom during a recent interview. She eventually became accustomed to the relaxed attitude of Missouri and was shocked by the situation she encountered on an out-of-town trip. “I took a bus trip from Atlanta to Pensacola and I encountered the worse racism that I have ever seen. I was at bus stop, I went in to be served and they would not serve me. There was a policeman sitting there at the table and he told me that privately owned places could select not to serve you.” Newsom describes her experience of marching in Montgomery as being one with a purpose. “We felt as though we achieved something - we felt a sense of unity,” Newsom said. “We were very excited (because) we were going to hear from Martin Luther King. To actually be in the presence of him and the other civil rights workers there was just such enthusiasm and excitement yet there was also some apprehension of what we might encounter.” Many of the marchers showed their inspiration and determination while pressing forward towards the grounds of the Alabama Capitol building. Newsom recalled that the marchers were singing the lyrics “ain’t gonna let nobody turn me around” and “we shall overcome.” “ I started seeing people just like me,” Newsom said. “I don’t recall any of the scowling, the hitting, the things I would see on TV later. I just saw a sea of humanity marching towards the Capitol. I don’t remember what Martin Luther King said but it was always the same message: keep the faith; we’re going to get where we’re going and let us remember what our purpose is.” Newsom offers advice on what individuals can do to make their society a more productive and peaceful place. “We have come a long way and we have ways to change things that we did not have before,” Newsom said. “You need to work in positive ways to change.” Referencing the recent unrest in Ferguson, Mo., she believes that people become destructive as a way to show and vent anger. Her generation, she says, was raised to react in lawful ways – and believe in hope. “We have faith to do things in a way that was lawful and it makes me sad what people do when they feel without hope, and there is hope,” Newsom says. “Non-violence does work - we need to include everyone to make this world a better place.” Newsom graduated from Lincoln in 1969 and describes her experience at Lincoln as, “I grew up and did more growing at Lincoln than I think I did for the rest of my life.”

Motivating the use of public transit through a mobile glanceable display

With increasing concerns about the impact of global warming on human life, policy makers around the world and researchers have sought for technological solutions that have the potential to attenuate this process. This thesis describes the design and evaluation of an information appliance that aims to increase the use of public transportation. We developed a mobile glanceable display that, being aware of the user’s transportation routines, provides awareness cues about bus arrival time, grounded upon the vision of Ambient Intelligence. We present the design process we followed, from ideation to building a prototype and conducting a field study, and conclude with a set of guidelines for the design of relevant personal information systems. More specifically we seek to test the following hypotheses: 1) That the tangible prototype that provides ambient cues will be used more frequently than a similar purpose mobile app, 2) That the tangible prototype will reduce the waiting time at the bus stop, 3) That the tangible prototype will result to reduced anxiety on passengers, 4) That the tangible prototype will result to an increase in the perceived reliability of the transit service, 5) That the tangible prototype will enhance users’ efficiency in reading the bus schedules and 6) That the tangible prototype will make individuals more likely to use public transit. In a field study, we compare the tangible prototype against the mobile app and a control condition where participants were given no external support in obtaining bus arrival information, other than their existing routines. Using qualitative and quantitative data, we test the aforementioned hypotheses and explore users’ reactions to the prototype we developed.

Motivating the use of public transit through a mobile glanceable display

With increasing concerns about the impact of global warming on human life, policy makers around the world and researchers have sought for technological solutions that have the potential to attenuate this process. This thesis describes the design and evaluation of an information appliance that aims to increase the use of public transportation. We developed a mobile glanceable display that, being aware of the user’s transportation routines, provides awareness cues about bus arrival time, grounded upon the vision of Ambient Intelligence. We present the design process we followed, from ideation to building a prototype and conducting a field study, and conclude with a set of guidelines for the design of relevant personal information systems. More specifically we seek to test the following hypotheses: 1) That the tangible prototype that provides ambient cues will be used more frequently than a similar purpose mobile app, 2) That the tangible prototype will reduce the waiting time at the bus stop, 3) That the tangible prototype will result to reduced anxiety on passengers, 4) That the tangible prototype will result to an increase in the perceived reliability of the transit service, 5) That the tangible prototype will enhance users’ efficiency in reading the bus schedules and 6) That the tangible prototype will make individuals more likely to use public transit. In a field study, we compare the tangible prototype against the mobile app and a control condition where participants were given no external support in obtaining bus arrival information, other than their existing routines. Using qualitative and quantitative data, we test the aforementioned hypotheses and explore users’ reactions to the prototype we developed.

Failure to Stop for School Bus Convictions by County of Occurrence 2009-2014, May 8, 2015

Failure to stop for school bus convictions by county from 2009-2014.

Development of a composite line source emission model for traffic interrupted microenvironments and its application in particle number emissions at a bus station

A composite line source emission (CLSE) model was developed to specifically quantify exposure levels and describe the spatial variability of vehicle emissions in traffic interrupted microenvironments. This model took into account the complexity of vehicle movements in the queue, as well as different emission rates relevant to various driving conditions (cruise, decelerate, idle and accelerate), and it utilised multi-representative segments to capture the accurate emission distribution for real vehicle flow. Hence, this model was able to quickly quantify the time spent in each segment within the considered zone, as well as the composition and position of the requisite segments based on the vehicle fleet information, which not only helped to quantify the enhanced emissions at critical locations, but it also helped to define the emission source distribution of the disrupted steady flow for further dispersion modelling. The model then was applied to estimate particle number emissions at a bi-directional bus station used by diesel and compressed natural gas fuelled buses. It was found that the acceleration distance was of critical importance when estimating particle number emission, since the highest emissions occurred in sections where most of the buses were accelerating and no significant increases were observed at locations where they idled. It was also shown that emissions at the front end of the platform were 43 times greater than at the rear of the platform. Although the CLSE model is intended to be applied in traffic management and transport analysis systems for the evaluation of exposure, as well as the simulation of vehicle emissions in traffic interrupted microenvironments, the bus station model can also be used for the input of initial source definitions in future dispersion models.

Quantification of particle emission characteristics and development of an emission model for use in transport microenvironments affected by traffic emissions

Vehicle emitted particles are of significant concern based on their potential to influence local air quality and human health. Transport microenvironments usually contain higher vehicle emission concentrations compared to other environments, and people spend a substantial amount of time in these microenvironments when commuting. Currently there is limited scientific knowledge on particle concentration, passenger exposure and the distribution of vehicle emissions in transport microenvironments, partially due to the fact that the instrumentation required to conduct such measurements is not available in many research centres. Information on passenger waiting time and location in such microenvironments has also not been investigated, which makes it difficult to evaluate a passenger’s spatial-temporal exposure to vehicle emissions. Furthermore, current emission models are incapable of rapidly predicting emission distribution, given the complexity of variations in emission rates that result from changes in driving conditions, as well as the time spent in driving condition within the transport microenvironment. In order to address these scientific gaps in knowledge, this work conducted, for the first time, a comprehensive statistical analysis of experimental data, along with multi-parameter assessment, exposure evaluation and comparison, and emission model development and application, in relation to traffic interrupted transport microenvironments. The work aimed to quantify and characterise particle emissions and human exposure in the transport microenvironments, with bus stations and a pedestrian crossing identified as suitable research locations representing a typical transport microenvironment. Firstly, two bus stations in Brisbane, Australia, with different designs, were selected to conduct measurements of particle number size distributions, particle number and PM2.5 concentrations during two different seasons. Simultaneous traffic and meteorological parameters were also monitored, aiming to quantify particle characteristics and investigate the impact of bus flow rate, station design and meteorological conditions on particle characteristics at stations. The results showed higher concentrations of PN20-30 at the station situated in an open area (open station), which is likely to be attributed to the lower average daily temperature compared to the station with a canyon structure (canyon station). During precipitation events, it was found that particle number concentration in the size range 25-250 nm decreased greatly, and that the average daily reduction in PM2.5 concentration on rainy days compared to fine days was 44.2 % and 22.6 % at the open and canyon station, respectively. The effect of ambient wind speeds on particle number concentrations was also examined, and no relationship was found between particle number concentration and wind speed for the entire measurement period. In addition, 33 pairs of average half-hourly PN7-3000 concentrations were calculated and identified at the two stations, during the same time of a day, and with the same ambient wind speeds and precipitation conditions. The results of a paired t-test showed that the average half-hourly PN7-3000 concentrations at the two stations were not significantly different at the 5% confidence level (t = 0.06, p = 0.96), which indicates that the different station designs were not a crucial factor for influencing PN7-3000 concentrations. A further assessment of passenger exposure to bus emissions on a platform was evaluated at another bus station in Brisbane, Australia. The sampling was conducted over seven weekdays to investigate spatial-temporal variations in size-fractionated particle number and PM2.5 concentrations, as well as human exposure on the platform. For the whole day, the average PN13-800 concentration was 1.3 x 104 and 1.0 x 104 particle/cm3 at the centre and end of the platform, respectively, of which PN50-100 accounted for the largest proportion to the total count. Furthermore, the contribution of exposure at the bus station to the overall daily exposure was assessed using two assumed scenarios of a school student and an office worker. It was found that, although the daily time fraction (the percentage of time spend at a location in a whole day) at the station was only 0.8 %, the daily exposure fractions (the percentage of exposures at a location accounting for the daily exposure) at the station were 2.7% and 2.8 % for exposure to PN13-800 and 2.7% and 3.5% for exposure to PM2.5 for the school student and the office worker, respectively. A new parameter, “exposure intensity” (the ratio of daily exposure fraction and the daily time fraction) was also defined and calculated at the station, with values of 3.3 and 3.4 for exposure to PN13-880, and 3.3 and 4.2 for exposure to PM2.5, for the school student and the office worker, respectively. In order to quantify the enhanced emissions at critical locations and define the emission distribution in further dispersion models for traffic interrupted transport microenvironments, a composite line source emission (CLSE) model was developed to specifically quantify exposure levels and describe the spatial variability of vehicle emissions in traffic interrupted microenvironments. This model took into account the complexity of vehicle movements in the queue, as well as different emission rates relevant to various driving conditions (cruise, decelerate, idle and accelerate), and it utilised multi-representative segments to capture the accurate emission distribution for real vehicle flow. This model does not only helped to quantify the enhanced emissions at critical locations, but it also helped to define the emission source distribution of the disrupted steady flow for further dispersion modelling. The model then was applied to estimate particle number emissions at a bidirectional bus station used by diesel and compressed natural gas fuelled buses. It was found that the acceleration distance was of critical importance when estimating particle number emission, since the highest emissions occurred in sections where most of the buses were accelerating and no significant increases were observed at locations where they idled. It was also shown that emissions at the front end of the platform were 43 times greater than at the rear of the platform. The CLSE model was also applied at a signalled pedestrian crossing, in order to assess increased particle number emissions from motor vehicles when forced to stop and accelerate from rest. The CLSE model was used to calculate the total emissions produced by a specific number and mix of light petrol cars and diesel passenger buses including 1 car travelling in 1 direction (/1 direction), 14 cars / 1 direction, 1 bus / 1 direction, 28 cars / 2 directions, 24 cars and 2 buses / 2 directions, and 20 cars and 4 buses / 2 directions. It was found that the total emissions produced during stopping on a red signal were significantly higher than when the traffic moved at a steady speed. Overall, total emissions due to the interruption of the traffic increased by a factor of 13, 11, 45, 11, 41, and 43 for the above 6 cases, respectively. In summary, this PhD thesis presents the results of a comprehensive study on particle number and mass concentration, together with particle size distribution, in a bus station transport microenvironment, influenced by bus flow rates, meteorological conditions and station design. Passenger spatial-temporal exposure to bus emitted particles was also assessed according to waiting time and location along the platform, as well as the contribution of exposure at the bus station to overall daily exposure. Due to the complexity of the interrupted traffic flow within the transport microenvironments, a unique CLSE model was also developed, which is capable of quantifying emission levels at critical locations within the transport microenvironment, for the purpose of evaluating passenger exposure and conducting simulations of vehicle emission dispersion. The application of the CLSE model at a pedestrian crossing also proved its applicability and simplicity for use in a real-world transport microenvironment.

Evaluation of Suitable Locations for Generation Expansion in Restructured Power Systems: A Novel Concept of T-index Thukaram

In developing countries, a high rate of growth in the demand for electric energy is felt, and so the addition of new generating units becomes inevitable. In deregulated power systems, private generating stations are encouraged to add new generations. Some of the factors considered while placing a new generating unit are: availability of esources, ease of transmitting power, distance from the load centre, etc. Finding the most appropriate locations for generation expansion can be done by running repeated power flows and carrying system studies like analyzing the voltage profile, voltage stability, loss analysis, etc. In this paper a new methodology is proposed which will mainly consider the existing network topology. A concept of T-index is introduced in this paper, which considers the electrical distances between generator and load nodes. This index is used for ranking the most significant new generation expansion locations and also indicates the amount of permissible generations that can be installed at these new locations. This concept facilitates for the medium and long term planning of power generation expansions within the available transmission corridors. Studies carried out on an EHV equivalent 10-bus system and IEEE 30 bus systems are presented for illustration purposes.

Optimization of bus allocation to depots by minimizing dead kilometers

In metropolitan cities, public transportation service plays a vital role in mobility of people, and it has to introduce new routes more frequently due to the fast development of the city in terms of population growth and city size. Whenever there is introduction of new route or increase in frequency of buses, the nonrevenue kilometers covered by the buses increases as depot and route starting/ending points are at different places. This non-revenue kilometers or dead kilometers depends on the distance between depot and route starting point/ending point. The dead kilometers not only results in revenue loss but also results in an increase in the operating cost because of the extra kilometers covered by buses. Reduction of dead kilometers is necessary for the economic growth of the public transportation system. Therefore, in this study, the attention is focused on minimizing dead kilometers by optimizing allocation of buses to depots depending upon the shortest distance between depot and route starting/ending points. We consider also depot capacity and time period of operation during allocation of buses to ensure parking safety and proper maintenance of buses. Mathematical model is developed considering the aforementioned parameters, which is a mixed integer program, and applied to Bangalore Metropolitan Transport Corporation (BMTC) routes operating presently in order to obtain optimal bus allocation to depots. Database for dead kilometers of depots in BMTC for all the schedules are generated using the Form-4 (trip sheet) of each schedule to analyze depot-wise and division-wise dead kilometers. This study also suggests alternative locations where depots can be located to reduce dead kilometers. Copyright (C) 2015 John Wiley & Sons, Ltd.

A mixed-integer linear programming approach to the optimization of event-bus schedules: a scheduling application in the tourism sector

This paper deals with “The Enchanted Journey,” which is a daily event tour booked by Bollywood-film fans. During the tour, the participants visit original sites of famous Bollywood films at various locations in Switzerland; moreover, the tour includes stops for lunch and shopping. Each day, up to five buses operate the tour. For operational reasons, however, two or more buses cannot stay at the same location simultaneously. Further operative constraints include time windows for all activities and precedence constraints between some activities. The planning problem is how to compute a feasible schedule for each bus. We implement a two-step hierarchical approach. In the first step, we minimize the total waiting time; in the second step, we minimize the total travel time of all buses. We present a basic formulation of this problem as a mixed-integer linear program. We enhance this basic formulation by symmetry-breaking constraints, which reduces the search space without loss of generality. We report on computational results obtained with the Gurobi Solver. Our numerical results show that all relevant problem instances can be solved using the basic formulation within reasonable CPU time, and that the symmetry-breaking constraints reduce that CPU time considerably.

Endemic tuberculosis, the homeless, and public transportation: A merging of geographical information systems surveillance and the Houston Tuberculosis Initiative Surveillance project

To reach the goals established by the Institute of Medicine (IOM) and the Centers for Disease Control's (CDC) STOP TB USA, measures must be taken to curtail a future peak in Tuberculosis (TB) incidence and speed the currently stagnant rate of TB elimination. Both efforts will require, at minimum, the consideration and understanding of the third dimension of TB transmission: the location-based spread of an airborne pathogen among persons known and unknown to each other. This consideration will require an elucidation of the areas within the U.S. that have endemic TB. The Houston Tuberculosis Initiative (HTI) was a population-based active surveillance of confirmed Houston/Harris County TB cases from 1995–2004. Strengths in this dataset include the molecular characterization of laboratory confirmed cases, the collection of geographic locations (including home addresses) frequented by cases, and the HTI time period that parallels a decline in TB incidence in the United States (U.S.). The HTI dataset was used in this secondary data analysis to implement a GIS analysis of TB cases, the locations frequented by cases, and their association with risk factors associated with TB transmission. ^ This study reports, for the first time, the incidence of TB among the homeless in Houston, Texas. The homeless are an at-risk population for TB disease, yet they are also a population whose TB incidence has been unknown and unreported due to their non-enumeration. The first section of this dissertation identifies local areas in Houston with endemic TB disease. Many Houston TB cases who reported living in these endemic areas also share the TB risk factor of current or recent homelessness. Merging the 2004–2005 Houston enumeration of the homeless with historical HTI surveillance data of TB cases in Houston enabled this first-time report of TB risk among the homeless in Houston. The homeless were more likely to be US-born, belong to a genotypic cluster, and belong to a cluster of a larger size. The calculated average incidence among homeless persons was 411/100,000, compared to 9.5/100,000 among housed. These alarming rates are not driven by a co-infection but by social determinants. The unsheltered persons were hospitalized more days and required more follow-up time by staff than those who reported a steady housing situation. The homeless are a specific example of the increased targeting of prevention dollars that could occur if TB rates were reported for specific areas with known health disparities rather than as a generalized rate normalized over a diverse population. ^ It has been estimated that 27% of Houstonians use public transportation. The city layout allows bus routes to run like veins connecting even the most diverse of populations within the metropolitan area. Secondary data analysis of frequent bus use (defined as riding a route weekly) among TB cases was assessed for its relationship with known TB risk factors. The spatial distribution of genotypic clusters associated with bus use was assessed, along with the reported routes and epidemiologic-links among cases belonging to the identified clusters. ^ TB cases who reported frequent bus use were more likely to have demographic and social risk factors associated with poverty, immune suppression and health disparities. An equal proportion of bus riders and non-bus riders were cultured for Mycobacterium tuberculosis, yet 75% of bus riders were genotypically clustered, indicating recent transmission, compared to 56% of non-bus riders (OR=2.4, 95%CI(2.0, 2.8), p<0.001). Bus riders had a mean cluster size of 50.14 vs. 28.9 (p<0.001). Second order spatial analysis of clustered fingerprint 2 (n=122), a Beijing family cluster, revealed geographic clustering among cases based on their report of bus use. Univariate and multivariate analysis of routes reported by cases belonging to these clusters found that 10 of the 14 clusters were associated with use. Individual Metro routes, including one route servicing the local hospitals, were found to be risk factors for belonging to a cluster shown to be endemic in Houston. The routes themselves geographically connect the census tracts previously identified as having endemic TB. 78% (15/23) of Houston Metro routes investigated had one or more print groups reporting frequent use for every HTI study year. We present data on three specific but clonally related print groups and show that bus-use is clustered in time by route and is the only known link between cases in one of the three prints: print 22. (Abstract shortened by UMI.)^

A Ride-Sharing System with High Capacity Vehicles and Flexible Meeting Points

In many major cities, fixed route transit systems such as bus and rail serve millions of trips per day. These systems have people collect at common locations (the station or stop), and board at common times (for example according to a predetermined schedule or headway). By using common service locations and times, these modes can consolidate many trips that have similar origins and destinations or overlapping routes. However, the routes are not sensitive to changing travel patterns, and have no way of identifying which trips are going unserved, or are poorly served, by the existing routes. On the opposite end of the spectrum, personal modes of transportation, such as a private vehicle or taxi, offer service to and from the exact origin and destination of a rider, at close to exactly the time they desire to travel. Despite the apparent increased convenience to users, the presence of a large number of small vehicles results in a disorganized, and potentially congested road network during high demand periods. The focus of the research presented in this paper is to develop a system that possesses both the on-demand nature of a personal mode, with the efficiency of shared modes. In this system, users submit their request for travel, but are asked to make small compromises in their origin and destination location by walking to a nearby meeting point, as well as slightly modifying their time of travel, in order to accommodate other passengers. Because the origin and destination location of the request can be adjusted, this is a more general case of the Dial-a-Ride problem with time windows. The solution methodology uses a graph clustering algorithm coupled with a greedy insertion technique. A case study is presented using actual requests for taxi trips in Washington DC, and shows a significant decrease in the number of vehicles required to serve the demand.

Diesel bus emissions of submicrometer particles measured in a tunnel study

The emission factors of a bus fleet consisting of approximately three hundreds diesel powered buses were measured in a tunnel study under well controlled conditions during a two-day monitoring campaign in Brisbane. The number concentration of particles in the size range 0.017-0.7 m was monitored simultaneously by two Scanning Mobility Particle Sizers located at the tunnel’s entrance and exit. The mean value of the number emission factors was found to be (2.44±1.41)×1014 particles km-1. The results are in good agreement with the emission factors determined from steady-state dynamometer testing of 12 buses from the same Brisbane City bus fleet, thus indicating that when carefully designed, both approaches, the dynamometer and on-road studies, can provide comparable results, applicable for the assessment of the effect of traffic emissions on airborne particle pollution.