This thesis focuses on two important problems related to DDDAS: interest management (data distribution) and prediction models. In order to reduce communication overhead, we propose a new interest management mechanism for mobile peer-to-peer systems. This approach involves dividing the entire space into cells and using an efficient sorting algorithm to sort the regions in each cell. A mobile landmarking scheme is introduced to implement this sort-based scheme in mobile peer-to-peer systems. The design does not require a centralized server, but rather, every peer can become a mobile landmark node to take a server-like role to sort and match the regions. Experimental results show that the scheme has better computational efficiency for both static and dynamic matching. In order to improve communication efficiency, we present a travel time prediction model based on boosting, an important machine learning technique, and combine boosting and neural network models to increase prediction accuracy. We also explore the relationship between the accuracy of travel time prediction and the frequency of traffic data collection with the long term goal of minimizing bandwidth consumption. Several different sets of experiments are used to evaluate the effectiveness of this model. The results show that the boosting neural network model outperforms other predictors.

The context of this study is the increasing need for public transport as issues over high private vehicle usage are becoming increasingly obvious. Public transport services need to compete with private transport to improve patronage, and issues with reliability need to be addressed. Bus bunching affects reliability through disruptions to the scheduled headways. The purpose of this study was to collect and analyse data to compare how travel time and dwell time vary, to explore the variation of key variables, and to better understand the sources of these variations. The Orbiter bus service in Christchurch was used as a case study, as it is particularly vulnerable to bus bunching. The dwell time was found to be more variable than travel time. It appeared the Canterbury earthquake had significantly reduced the average speeds for the Orbiter service. In 1964, Newell and Potts described a basic bus bunching theory, which was used as the basis for an Excel bus bunching model. This model allows input variables to vary stochastically. Random values were generated from four specified distributions derived from manually collected data, allowing variance across all bus platforms and buses. However the complexity resulted in stability and difficulty in achieving convergence, so the model was run in single Monte Carlo simulations. The outputs were realistic and showed a higher degree of bunching behaviour than previous models. The model demonstrated bunching phenomena that had not been observed in previous models, including spontaneously un-pairing, overtaking of buses delayed at platforms, and odd-numbered bunches of three buses. Furthermore, the study identified areas of further research for data collection and model development.

No description available.

L’hémophilie est une maladie héréditaire rare qui affecte la coagulation. Elle réclame des soins rapides pour les patients. En raison du degré de spécialisation requis et du coût des médicaments, les lieux de soins sont rares sur le territoire. Il y adonc un fort enjeu relatif à l’accessibilité. En Bretagne, les patients les plus sévèrement atteints par la maladie ont été observés en plus forte proportion que les autres à proximité des centres de traitement de l’hémophilie. Pourtant, ladistance n’est pas le seul critère jouant sur la qualité de l’accès aux soins. L’expérience personnelle, la facilité à se déplacer ou la sévérité de la maladie peuvent contraindre ou faciliter l’accès aux soins. En cas d’urgences, les patientsne rejoignent pas toujours le lieu de soins le plus proche, parce qu’ils privilégient les structures spécialisées dans l’hémophilie. Des cas de mobilités résidentielle provoqués par la mauvaise accessibilité ont été observés en Bretagne. Parailleurs, la maladie limite la mobilité quotidienne et occasionnelle, agit comme une contrainte supplémentaire dans la recherche d’un emploi ou dans le cadre de l’accession à la propriété. La thèse a ouvert des perspectives d’étude surl’accessibilité à l’échelle nationale ou élargies à d’autres maladies hémorragiques. Méthodologiquement, on a montré l’intérêt de l’emploi successif de SIG, d’un questionnaire et d’entretiens auprès des patients / Haemophilia is a rare hereditary disorder affecting blood clotting. It needs quick care for patients. Considering the specialization required for health care and the costs of the medicines, healthcare resources are pretty sparse on theterritory. Accessibility is then a major issue. In Brittany, patients living with a severe form of the disease have been observed in the areas closed to the haemophilia centres in wider proportion than the others. Nevertheless, distance is not the onlycriteria related with the quality of healthcare access. Life experience, ease of movement or severity of the disease can also constraint or facilitate healthcare access. Each patient has its own perception of distance. In case of emergency, patients do not always reach the closest hospital. They prefer to go in a hospital specialized in haemophilia care. Some cases ofresidential mobility have been noticed in Brittany. Otherwise, haemophilia limits the daily and occasional mobility, affecting joins, acts like as an additional constraint in job search or in the pursuit of homeownership. The thesis has openedstudies opportunities at a national scale or extended to others blood clotting disorders. Methodologically, we confirmed the interest in using successively GIS, questionnaires and interviews with patients

Based on a time-use model with a sound theoretical basis and carefully collected data for Austria, the value of leisure (VoL) for different population segments has been estimated. Through the combination of these results with mode-specific values of travel time savings from a related study based on the same data, the first mode-specific values of time assigned to travel (VTAT) were calculated. Data was collected using a Mobility-Activity-Expenditure Diary, a novel survey format which gathers all activities, expenditures, and travel decisions from the same individuals for 1 week in a diary-based format. The average VoL is 8.17 Euro/h, which is below the mean wage of 12.14 Euro/h, indicating that the value of work is, on average, negative. Regarding the reliability of the VoL, we show its sensitivity to the variance of working time in a sample, something that has been ignored in previous studies and could be used to avoid inadequate segmentation. We controlled this effect in the analysis of the heterogeneity of the VoL across the population by estimating the parameters from the total (unsegmented) dataset with single interaction terms. We find that the VTAT is strictly negative for walking, predominantly negative for cycling and car, and predominantly positive for public transport with 0.27 Euro/h on average. The positive VTAT for public transport is a strong indication for the importance of travel conditions, in turn suggesting that improvements in travel conditions of public transport might be as important as investing in shorter travel times.

Two-echelon vehicle routing problems which contain synchronization between vehicles can be deeply impacted by time uncertainty, because one vehicle's delay can propagate to other vehicles. In this paper, we evaluate the deterministic solution of such a problem based on simulated travel time scenarios. The information obtained by simulation is incorporated in the optimization procedure iteratively. Computational results show that the degree of synchronization in an instance is directly correlated with the potential improvements by reoptimization. We present findings on the number of travel time scenarios required to obtain a representative picture of the stochastic solutions. In addition, we demonstrate that time dependent travel times can be aggregated on a city-wide level and linearized as a function of free flow times without major loss of reliability.

Direct left turn (DLT) movements have a lot safety and operation problems. They increase conflicts, delay and reduce capacity of the roadway. Increasing, many states and transportation agencies are considering using right-turns followed by u-turns as an alternative to direct left turns. Recently, Florida state are planning to close median openings in order to reduce the safety and operational problems caused by DLT. The left-turn egress movement would then to be made by turning right to the arterial road and then making a u-turn at an available downstream median opening or a signalized intersection. FDOT sponsored a project in 2001 (Methodology to quantify the Effects of Access Management Treatments on Roadway Operations and Safety) which has provided useful information on operational effect of right-turn followed by u-turn at median opening as an alternative to the direct left turn from driveways. However, the impact of the treatment---right-turn followed by u-turn at signalized intersection as an alternative to direct left turn is still not clear. A operational comparison of this treatment would be valuable. Field data collection was conducted to quantify the operational effects of right turn followed by u-turn at signalized intersection versus direct left turns. Totally eight sites around the Tampa Bay area were selected and more than 300 hours field data including delay, travel time, traffic volume, traffic control, headway, signal timing and geometric data were collected. Data reduction was conducted after that and several statistic models were developed evaluating total travel time, travel delay of these two movements and the ratio of drivers choice of RTUT versus DLT. As the conclusion, the study found that RTUT followed by U-turn at signalized intersection has longer delay and longer travel time as compared to DLT and the existence of long cycle downstream signal will discourage driver's selection of RTUT. There conclusions are very important in that they provided decision makers with useful information regarding the selection of the suitable U-turn location.

This thesis presents an overall picture of demographic and socio-economic characteristics as well as journey to work travel behavior characteristics in Florida. In addition, detailed comparisons of journey to work private vehicle occupancy distribution, travel time distribution, mode choice and departure time distribution by household and individual characteristics are also provided based on three data files: American Community Survey Public Use Microdata Samples data file, Summary File 3 Public Use Microdata Samples 1% and Public Use Microdata Samples 5% data files. Utilizing the three data files, this thesis not only investigates current commuting patterns but also provides more reliable information on current journey to work characteristics and helps to gain knowledge that is useful to identify problems and provide creative solutions on related transportation issues in the state of Florida. In analyzing the data, several socio-economic and journey to work travel behavior characteristics were identified. Interesting findings include the lower utilization of transit, the lower private vehicle occupancies for individuals in Florida, and different journey to work departure time distribution by gender, by young people and by senior citizens from other adult categories. The data analysis shows that the three data files reflect acknowledged demographic trends and capture known changes such as aging of population, smaller household size, and increasing car ownership. The comparison analysis shows that in most cases, ACS PUMS data files approximate SF3 PUMS 1% and 5% data files very well. The detailed comparison of the three data files regarding journey to work travel behavior characteristics in Florida is important to decision makers who will make informed choices when evaluating alternative transportation programs and related policy issues. The knowledge of reliability of data regarding journey to work travel behavior will also help transportation professionals for travel demand modeling, transportation and land use planning and related studies.

<p>Den 13:e juni 2004 invigdes det nya resecentrumet i Sandviken. Det anlades med avsikten att möjliggöra snabba och enkla byten mellan tåg, regionbussar, landsortsbussar och stadsbussar inom en och samma terminal. I samband med detta genomfördes också en linjenätsomläggning av den kommunala busstrafiken inom tätorten. Särskilt stor blev förändringen för stadsbusstrafiken som förutom att den fick en ny knutpunkt också hade</p><p>krav på sig att kostnadseffektiviseras då anslagen inte hade höjts för att täcka de ökande kostnaderna. Resultatet av linjenätsomläggningen för stadsbusstrafiken blev ett resurseffektivt linjenät med fem nya linjer och fyra trafikerande bussar varav endast en buss i trafik på kvällar och helger.</p><p>Resandet med stadsbusstrafiken i Sandviken har minskat med 30,4% sedan linjenätsomläggningen 2004 och även om minskningen för den totala, inomkommunala busstrafiken begränsar sig till drygt 9% under samma tidsperiod är indikationen att resenärerna har känt sig missnöjda med det nya stadsbusslinjenätet. Sedan linjenätsomläggningen har även stadens fysiska struktur förändrats med bland annat ett nytt, halvexternt köpcentra, Mosaiken, som inte tillgodoses med busstrafik idag. Samtidigt har biljettintäkterna minskat i takt med att resandet minskat och kostnadstäckningen (biljettintäkter/utgifter) är idag nere på 41%. Ett antal faktorer har visat sig ha särskild betydelse för ifall människor väljer att åka kollektivt eller inte, de viktigaste är: Restid, komfort, pris, pålitlighet och enkelhet. Syftet med detta arbete har varit att främst identifiera åtgärder i syfte att öka flexibiliteten och minska restiden med stadsbusstrafiken genom att optimera dagens linjenät med avseende på linjesträckning, turtäthet och yttäckning inom begränsade, ekonomiska ramar och på så sätt öka stadsbusstrafikens attraktionskraft. Med restiden menas här den totala restiden från dörr till dörr, även kallat "Hela resan". Metoden för arbetet har varit att dels applicera erfarenheter från andra orter på Sandviken i tillämpbara delar men också att ta resenärernas åsikter i beaktande liksom befolkningsstrukturen och resandemönster för såväl dagens som morgondagens behov. För ändamålet har busshållplatserna lagts in i ett GIS för att skapa underlag för en anpassning av avstånd, hastigheter och bussomlopp till restiderna och utformningen av tidtabellerna.</p><p>Resultatet visar att med några mindre förändringar i linjesträckningen och sex helt nya hållplatser tillsammans med en extra buss i trafik 74 timmar/veckan så kan den totala restiden med stadsbussarna minska mellan nästan alla platser inom tätorten under alla tider, samtidigt som resenärernas önskemål tillgodoses. Driftkostnadsökningen blir ca 24 600 kr/veckan vilket kräver en ökning med ca 930 resenärer/veckan (48 400/år) för att uppnå 50% kostnadstäckning på den resandeökning som förslaget väntas medföra, en ökning som bedöms rimlig. I tillägg erhålls alla de samhällsekonomiska vinster som kollektivtrafiken alltid bidrar med, t.ex. en bättre miljö, bättre folkhälsa, minskat utrymmesbehov etc. Av erfarenheter från andra orter att döma så är en linjenätsomläggning bara en komponent i en lyckad kollektivtrafiksatsning och ska snarare ses som en väg in i en "god cirkel" där resandeökningar och satsningar/förbättringar av busstrafiken avlöser varandra. För en långsiktig helhetslösning krävs att den fysiska planeringen och kollektivtrafiken går hand i hand och kombineras såväl med restriktioner för biltrafiken som med satsningar på kollektivtrafiken.</p> / <p>The 13th of june 2004 the new central station for public transports was inaugurated in Sandviken. It was constructed with intention to connect local, regional and interregional busses to trains in order to enable quick and easy transfers within same terminal. In association to that, a restructure of the bus network within the city was accomplished. Those changes particularly affected the local busses which both got a new central bus stop but also had to be more effective in terms of costs since the subsidies had not been increased to cover the expenses. The new structure resulted in five local bus lines with four available busses of which only one of them in route on evenings and weekends. The local bus traffic travelling in Sandviken has decreased with 30,4% since the route restructure 2004 and even though the total travelling by bus in Sandviken has decreased with merely little more than 9% during same period it gives an indication of a dissatisfaction among the bus travellers. In addition, the physical structure of Sandviken has been changed significantly since 2004 with, among other things, a new shopping centre "Mosaiken" which is not provided by public transports at all today. Also the ticket incomes have decreased because of less travelling and the expense coverage (ticket incomes/expenses) has therefore dropped to 41%. A number of factors have shown to be particularly significant whether people choose public transports or not. The most important are: Travel time, comfort, charge, reliability, understand simplicity etc. The purpose of this paper was to identify measures in order to increase the local bus attraction by ameliorating flexibility and reduce travel times of the local buses. This was made by optimalizing today's bus route network with respect to line structure, travel frequencies and land coverage within specified, economical delimitations.</p><p>In this sense, travel time aim at the time from door to door, also called "The whole journey". The chosen method was to apply experiences from other towns to Sandviken in applicable parts and in conjunction with consideration of traveller's opinions, population structure and both today's travel patterns but also what is expected to arise in the future. For this purpose, every bus stop was put into a GIS in order to create data for analysing distances and velocities to adjust the creation of time tables.</p><p>The result shows that the total travel time to almost any place at any time within the city can be decreased as well as the traveller's requests by adding six new bus stops and adjusting the bus line system slightly together combined with one more bus in route 74 hours/week. That implies an increased running cost of approximately 24 600 SEK/week which requires an increase of roughly 930 passengers/week (48 4000/year) to cover up the expenses by 50%, an amount that is estimated to be plausible. In addition plenty of politic economical benefits like a cleaner environment, better public health, less need of space in urban environment etc, are achieved. Experiences from other cities have shown this kind of restructure of local busses can be one important part of a successful public transport concentration as well as an entry to a "gentle treadmill" where increased travelling and increased ticket incomes give possibilities to ameliorate the bus route standard gradually.</p><p>In order to create a sustainable solution in a longer perspective, the development of physical urban planning and traffic planning need to be collaborated and the suggested bus route restructure need to be combined with car restrictions and further investments and commitments.</p>

Den 13:e juni 2004 invigdes det nya resecentrumet i Sandviken. Det anlades med avsikten att möjliggöra snabba och enkla byten mellan tåg, regionbussar, landsortsbussar och stadsbussar inom en och samma terminal. I samband med detta genomfördes också en linjenätsomläggning av den kommunala busstrafiken inom tätorten. Särskilt stor blev förändringen för stadsbusstrafiken som förutom att den fick en ny knutpunkt också hade krav på sig att kostnadseffektiviseras då anslagen inte hade höjts för att täcka de ökande kostnaderna. Resultatet av linjenätsomläggningen för stadsbusstrafiken blev ett resurseffektivt linjenät med fem nya linjer och fyra trafikerande bussar varav endast en buss i trafik på kvällar och helger. Resandet med stadsbusstrafiken i Sandviken har minskat med 30,4% sedan linjenätsomläggningen 2004 och även om minskningen för den totala, inomkommunala busstrafiken begränsar sig till drygt 9% under samma tidsperiod är indikationen att resenärerna har känt sig missnöjda med det nya stadsbusslinjenätet. Sedan linjenätsomläggningen har även stadens fysiska struktur förändrats med bland annat ett nytt, halvexternt köpcentra, Mosaiken, som inte tillgodoses med busstrafik idag. Samtidigt har biljettintäkterna minskat i takt med att resandet minskat och kostnadstäckningen (biljettintäkter/utgifter) är idag nere på 41%. Ett antal faktorer har visat sig ha särskild betydelse för ifall människor väljer att åka kollektivt eller inte, de viktigaste är: Restid, komfort, pris, pålitlighet och enkelhet. Syftet med detta arbete har varit att främst identifiera åtgärder i syfte att öka flexibiliteten och minska restiden med stadsbusstrafiken genom att optimera dagens linjenät med avseende på linjesträckning, turtäthet och yttäckning inom begränsade, ekonomiska ramar och på så sätt öka stadsbusstrafikens attraktionskraft. Med restiden menas här den totala restiden från dörr till dörr, även kallat "Hela resan". Metoden för arbetet har varit att dels applicera erfarenheter från andra orter på Sandviken i tillämpbara delar men också att ta resenärernas åsikter i beaktande liksom befolkningsstrukturen och resandemönster för såväl dagens som morgondagens behov. För ändamålet har busshållplatserna lagts in i ett GIS för att skapa underlag för en anpassning av avstånd, hastigheter och bussomlopp till restiderna och utformningen av tidtabellerna. Resultatet visar att med några mindre förändringar i linjesträckningen och sex helt nya hållplatser tillsammans med en extra buss i trafik 74 timmar/veckan så kan den totala restiden med stadsbussarna minska mellan nästan alla platser inom tätorten under alla tider, samtidigt som resenärernas önskemål tillgodoses. Driftkostnadsökningen blir ca 24 600 kr/veckan vilket kräver en ökning med ca 930 resenärer/veckan (48 400/år) för att uppnå 50% kostnadstäckning på den resandeökning som förslaget väntas medföra, en ökning som bedöms rimlig. I tillägg erhålls alla de samhällsekonomiska vinster som kollektivtrafiken alltid bidrar med, t.ex. en bättre miljö, bättre folkhälsa, minskat utrymmesbehov etc. Av erfarenheter från andra orter att döma så är en linjenätsomläggning bara en komponent i en lyckad kollektivtrafiksatsning och ska snarare ses som en väg in i en "god cirkel" där resandeökningar och satsningar/förbättringar av busstrafiken avlöser varandra. För en långsiktig helhetslösning krävs att den fysiska planeringen och kollektivtrafiken går hand i hand och kombineras såväl med restriktioner för biltrafiken som med satsningar på kollektivtrafiken. / The 13th of june 2004 the new central station for public transports was inaugurated in Sandviken. It was constructed with intention to connect local, regional and interregional busses to trains in order to enable quick and easy transfers within same terminal. In association to that, a restructure of the bus network within the city was accomplished. Those changes particularly affected the local busses which both got a new central bus stop but also had to be more effective in terms of costs since the subsidies had not been increased to cover the expenses. The new structure resulted in five local bus lines with four available busses of which only one of them in route on evenings and weekends. The local bus traffic travelling in Sandviken has decreased with 30,4% since the route restructure 2004 and even though the total travelling by bus in Sandviken has decreased with merely little more than 9% during same period it gives an indication of a dissatisfaction among the bus travellers. In addition, the physical structure of Sandviken has been changed significantly since 2004 with, among other things, a new shopping centre "Mosaiken" which is not provided by public transports at all today. Also the ticket incomes have decreased because of less travelling and the expense coverage (ticket incomes/expenses) has therefore dropped to 41%. A number of factors have shown to be particularly significant whether people choose public transports or not. The most important are: Travel time, comfort, charge, reliability, understand simplicity etc. The purpose of this paper was to identify measures in order to increase the local bus attraction by ameliorating flexibility and reduce travel times of the local buses. This was made by optimalizing today's bus route network with respect to line structure, travel frequencies and land coverage within specified, economical delimitations. In this sense, travel time aim at the time from door to door, also called "The whole journey". The chosen method was to apply experiences from other towns to Sandviken in applicable parts and in conjunction with consideration of traveller's opinions, population structure and both today's travel patterns but also what is expected to arise in the future. For this purpose, every bus stop was put into a GIS in order to create data for analysing distances and velocities to adjust the creation of time tables. The result shows that the total travel time to almost any place at any time within the city can be decreased as well as the traveller's requests by adding six new bus stops and adjusting the bus line system slightly together combined with one more bus in route 74 hours/week. That implies an increased running cost of approximately 24 600 SEK/week which requires an increase of roughly 930 passengers/week (48 4000/year) to cover up the expenses by 50%, an amount that is estimated to be plausible. In addition plenty of politic economical benefits like a cleaner environment, better public health, less need of space in urban environment etc, are achieved. Experiences from other cities have shown this kind of restructure of local busses can be one important part of a successful public transport concentration as well as an entry to a "gentle treadmill" where increased travelling and increased ticket incomes give possibilities to ameliorate the bus route standard gradually. In order to create a sustainable solution in a longer perspective, the development of physical urban planning and traffic planning need to be collaborated and the suggested bus route restructure need to be combined with car restrictions and further investments and commitments.