A philosophical context for methods to estimate origin-destination trip matrices using link counts.

This paper creates a philosophical structure for classifying methods which estimate origin-destination matrices using link counts. It is claimed that the motivation for doing so is to help real-life transport planners use matrix estimation methods effectively, especially in terms of trading-off observational data with prior subjective input (typically referred to as 'professional judgement'). The paper lists a number of applications that require such methods, differentiating between relatively simple and highly complex applications. It is argued that a sound philosophical perspective is particularly important for estimating trip matrices in the latter type of application. As a result of this argument, a classification structure is built up through using concepts of realism, subjectivity, empiricism and rationalism. Emphasis is put on the fact that, in typical transport planning applications, none of these concepts is useful in its extreme form. The structure is then used to make a review of methods for estimating trip matrices using link counts, covering material published over the past 30 years. The paper concludes by making recommendations, both philosophical and methodological, concerning both practical applications and further research

A philosophical context for methods to estimate origin-destination trip matrices using link counts.

This paper creates a philosophical structure for classifying methods which estimate origin-destination matrices using link counts. It is claimed that the motivation for doing so is to help real-life transport planners use matrix estimation methods effectively, especially in terms of trading-off observational data with prior subjective input (typically referred to as 'professional judgement'). The paper lists a number of applications that require such methods, differentiating between relatively simple and highly complex applications. It is argued that a sound philosophical perspective is particularly important for estimating trip matrices in the latter type of application. As a result of this argument, a classification structure is built up through using concepts of realism, subjectivity, empiricism and rationalism. Emphasis is put on the fact that, in typical transport planning applications, none of these concepts is useful in its extreme form. The structure is then used to make a review of methods for estimating trip matrices using link counts, covering material published over the past 30 years. The paper concludes by making recommendations, both philosophical and methodological, concerning both practical applications and further research

Cost-effectiveness of cordon studies for trip matrix estimation from traffic counts

Cordon studies can substantially improve estimation of origin-destination (O/D) trip matrices from link traffic counts. This paper proposes a method for integrating cordon survey results in O/D matrix estimation. This method is applied to 5 inter-urban networks in the Valencia Region, focusing on the specific formulation of the O/D matrix estimation technique, the assignment model to be implemented, the selection of traffic count locations in the cordoned area and, especially, the selection of cordon survey stations and data collection. Cost-effectiveness of cordon survey selection is addressed. The results show that cost-effectiveness ratios tend to decrease with the number of surveyed cordons in the 5 networks analyzed. This is due to non-linear reduction of origin-destination estimation errors and economies of scale on conducting cordon surveys. The results of this study can be useful to assess decision-making when conducting cordon surveys in interurban networks. Once such decisions have been taken, the method presented in this paper can be applied to the whole O/D matrix estimation procedure.Torres Martínez, AJ. (2012). Cost-effectiveness of cordon studies for trip matrix estimation from traffic counts. http://hdl.handle.net/10251/1496

Energy Regulation, Roll Call Votes and Regional Resources: Evidence from Russia

This paper investigates the relative impact of regional energy production on the legislative choices of Russian Duma deputies on energy regulation between 1994 and 2003. We apply Poole’s optimal classification method of roll call votes using an ordered probit model to explain energy law reform in the first decade of Russia’s democratic transition. Our goal is to analyze the relative importance of home energy on deputies’ behavior, controlling for other factors such as party affiliation, electoral mandate, committee membership and socio-demographic parameters. We observe that energy resource factors have a considerable effect on deputies’ voting behavior. On the other hand, we concurrently find that regional economic preferences are constrained by the public policy priorities of the federal center that continue to set the tone in energy law reform in post-Soviet Russia.Energy Regulation, Energy Roll Law Reform, Energy Resources, Roll Call Votes, Legislative Politics, State Duma, Russia

Traffic modeling, forecasting and assignment in large-scale networks

Today, the development and evaluation of traffic management strategies heavily relies on microscopic traffic simulation models. In case detailed input (i.e. od matrix, signal timings, etc.) is extracted and incorporated in these simulators, they can provide valuable traffic state predictions. However, as this type of information is almost never available at the large-scale and traffic represents chaotic behavior in saturated networks, microscopic simulation models remain intractable and unstable. An alternative is a recently discovered network traffic model; macroscopic fundamental diagram (MFD). Nevertheless, large-scale traffic management strategies remain a big challenge partly due to unpredictability of choices of travelers (e.g. route, departure time and mode choice). Part I of the thesis is an attempt to fill this gap. Chapter 2, 3 and 4 elaborate new aspects of large-scale traffic modeling, and integrate route choice behavior into the modeling. Chapter 2 proposes a dynamic traffic assignment (DTA) model to establish equilibrium conditions in multi-region urban networks where the modeling is done through MFD dynamics. The method handles the stochastic components of the aggregated model through a sampling approach. In addition, the assignment model enables us to consider the response of drivers to changing traffic conditions in an aggregated modeling framework. Chapter 3 extends the DTA model presented in Chapter 2 to a route guidance system, where drivers are given a sequence of subregions to follow. Two aggregated models, region- and subregion-based models, are introduced to develop the guidance scheme and to test its effect, respectively. Notably, the challenge here is to translate certain variables across the traffic models without a loss of significance and assure certain degree of consistency. Chapter 4 extracts and reconstructs aggregated route choice patterns through an extensive GPS data set from taxis in a mega city. Observed GPS trajectories are first grouped together to provide a physical evidence for consistent route patterns. Second, in order to investigate the consistency of equilibrium assumptions considered in Chapter 2, observed trajectories are replaced with shortest path trajectories, and aggregated route choice patterns are reconstructed. Part II introduces novel travel time prediction and variability models. Travel time is a crucial performance measure in assessing the efficiency of transportation systems, and it provides a common index for both practitioners and travelers. Chapter 5 develops a travel time prediction model that jointly exploits traffic flow fundamentals and advanced data mining techniques. The prediction method detects the congestion patterns through the identification of active bottlenecks, and clusters the days with similar traffic patterns. This approach basically allows the model to train its predictions with relevant historical data sets. The method is applicable in oversaturated conditions and consistent with physics of traffic flow. Nevertheless, travelers not only consider travel time on average, but also value its variation. Day-to-day travel time variability, addressing the travel time variations of vehicles crossing the same route at the same period of time on different days, reveals interesting patterns. Departure time periods with similar mean travel times in the onset and offset of congestion exhibit quite different variance values. This phenomenon causes counter-clockwise hysteresis loops on the mean-variance curves. Chapter 6 investigates the empirical implications of hysteresis shape within the context of day-to-day travel time variability

Vertical specialisation and new regionalism

The increased spread in the location of value added coupled with the growing impetus for new forms of bilateral integration are re-shaping international economic activity. The world is becoming more regional and more fragmented but little empirical work has been dedicated to examining the nature of the links between these processes. This thesis aims to fill this gap in the literature. The primary aim of the first essay of this thesis is to extend current indicators of international production so that the bilateral degree of vertical specialisation can be captured. This has been one of the major hurdles in examining the links between vertical specialisation and Free Trade Agreements (FTAs). The comparative static analysis of this first essay reveals that there appears to be a high incidence of regional value chain activity and this motivates the aims of the second essay. It attempts to isolate the impact of an FTA on these flows through a theoretically derived gravity model of input trade. The results suggest that an FTA increases the use of intermediate inputs that are part of a bilateral value chain by 65%. Moreover, the results identify the presence of ‘magnification’ which implies that this type of trade is also more responsive to changes in trade costs and income variables. The third essay then looks at how the changing nature of trade affects the formation of new FTAs. It suggests that the propagation of international production alters the political economy dynamics of countries towards favouring further liberalisation. It also identifies regulatory quality and a growing FTA ‘contagion’ as determinants of new FTAs

An Information-Theoretic Framework for Consistency Maintenance in Distributed Interactive Applications

Distributed Interactive Applications (DIAs) enable geographically dispersed users to interact with each other in a virtual environment. A key factor to the success of a DIA is the maintenance of a consistent view of the shared virtual world for all the participants. However, maintaining consistent states in DIAs is difficult under real networks. State changes communicated by messages over such networks suffer latency leading to inconsistency across the application. Predictive Contract Mechanisms (PCMs) combat this problem through reducing the number of messages transmitted in return for perceptually tolerable inconsistency. This thesis examines the operation of PCMs using concepts and methods derived from information theory. This information theory perspective results in a novel information model of PCMs that quantifies and analyzes the efficiency of such methods in communicating the reduced state information, and a new adaptive multiple-model-based framework for improving consistency in DIAs. The first part of this thesis introduces information measurements of user behavior in DIAs and formalizes the information model for PCM operation. In presenting the information model, the statistical dependence in the entity state, which makes using extrapolation models to predict future user behavior possible, is evaluated. The efficiency of a PCM to exploit such predictability to reduce the amount of network resources required to maintain consistency is also investigated. It is demonstrated that from the information theory perspective, PCMs can be interpreted as a form of information reduction and compression. The second part of this thesis proposes an Information-Based Dynamic Extrapolation Model for dynamically selecting between extrapolation algorithms based on information evaluation and inferred network conditions. This model adapts PCM configurations to both user behavior and network conditions, and makes the most information-efficient use of the available network resources. In doing so, it improves PCM performance and consistency in DIAs

Total Quality Management and Six Sigma

In order to survive in a modern and competitive environment, organizations need to carefully organize their activities regarding quality management. TQM and six sigma are the approaches that have been successful in solving intricate quality problems in products and services. This volume can help those who are interested in the quality management field to understand core ideas along with contemporary efforts done in the field and authored as case studies in this volume. This volume may be useful to students, academics and practitioners across diversified disciplines