Dissertations / Theses on the topic 'Traffic engineering Research Australia'

The most promising switching technique for B-ISDN (broadband integrated service digital network) is the ATM (asynchronous transfer mode). In an ATM network, all information, data, voice and video, is packetized and divided into fixed length data blocks called cells. The cells from different connections are carried through a multiplexer, and asynchronously transmitted through the network. Statistical multiplexing of cells allows the possible reduction of the bandwidth assigned to each single source. That increased flexibility with respect to the bandwidth requirement provides a chance for better, more economical utilization of the network resources. On the other hand, severe network congestion can occur when a large number of traffic sources become active simultaneously. Since most traffic sources in ATM networks are bursty, some congestion control must be applied to each source in order to maintain the required GOS (grade of service) and provide fairness among the users. We introduce the discrete batch Markovian arrival process, which is a versatile and tractable class of Markov renewal processes. This class of processes provides a very powerful modeling tool. The Palm measure, variance time curve, asymptotic normality of the counts are derived. The interarrival time distribution for the single arrivals case are discussed. We also address some issues related to the simulation of this class of processes. Two traffic shaping, or smoothing schemes are investigated in this dissertation: jumping windows with regular placement and an input rate control model, introduced by Ohta et al. (21). The discrete Markovian arrival process with single arrivals serves as the model for the arrival process. In the first model, analytical expressions for the loss probability, packet delay and the interarrival times for the shaped process in steady state are derived. The second model leads to a highly degenerate partitioned Markov chain of QBD (Quasi-Birth-and-Death) type. Special algorithms involving matrices of lower order are obtained by exploiting the special structure of the Markov chain. Some performance measurements are derived. The algorithmic implementation of these results is also discussed. Finally, we examine some specific examples, applying both the analytical results and simulation, to demonstrate the effectiveness of the two traffic shaping schemes.

The Australian road freight industry is moving towards improved efficiency and competitiveness through the use of larger and more innovative multi-combination vehicles (MCVs). However, this move has brought about concern over the interaction of these new vehicles with the environment, existing infrastructure and other road users. The aim of this research project was to assess the impacts of MCVs on traffic operation and safety. This was undertaken by initially reviewing cunent literature on MCVs. It was recognised that the Australian heavy vehicle fleet had modernised since a number of performance levels were established and the review highlighted the need for greater research to obtain current data and either develop new performance levels or validate previous research. This study selected four characteristics for analysis: passenger car equivalence (PCE), clearance time, acceleration, and tracking ability on a straight path. These characteristics were considered to be the most influential on the interaction between MCVs and other road users. Vehicle operational data was collected between April and August 2001, for each characteristic, via a series of three in-field test programs located on controlled road sections in Queensland: south of Charters Towers; west of Toowoomba; and at the Mount Cotton Training Centre, south-east of Brisbane. All tested MCVs recorded a PCE greater than 2 for a through-movement on a flat grade with no adjacent traffic lanes. It was determined that assuming a constant PCE does not account for the variation in values attained for different MCV types. Under circumstances where MCV volumes are significant, it would be more accurate to establish the average PCE value of each relevant movement at the intersection based on PCEs across the traffic spectrum and using the values provided in Table 5.4. Further testing is needed to establish PCE values on grades, turning movements, non-standard lane widths, and for vehicles such as Double Road Trains, AB-Triples and AAB-Quads. The intersection clearance time characteristics proposed by NRTC (2001) were found to be conservative for the MCV s tested. To cover a greater range of operating conditions, clearance time requirements for a MCV on a particular grade may be derived from the trajectory curves provided in Figures 6.3 to 6.6. Further in-field testing should be undertaken to obtain additional trajectory curves for MCVs with lower powered engines. Speed curves were developed (Figures 6.9 to 6.12) which may be used with the above trajectory curves to derive vehicle speeds at specific distances, on particular grades. This would enable assessors to determine the minimum entry lane length required to allow a MCV to attain adequate speed to merge into moving traffic, and also indicate whether an overtaking lane is required on a steep ascending grade. Further testing should be undertaken to establish speed curves over a higher speed and distance range . . Queensland Department of Main Roads (1998b) recommended an average acceleration rate for use in sight distance calculations. This was found from testing to be generally conservative for a B-Double, although too high for all the other MCVs tested. The trajectory curves provided in Figures 6.15 to 6.18 were developed to examine the variation in acceleration as test vehicles depart from rest. These may be used to determine average acceleration rates, over specific distances and on particular grades. Alternatively, sight distance requirements may be determined from equation (6.9), using clearance times established from equation (6.5) or Figures 6.3 to 6.6. Data on tracking ability of MCVs on a straight path was collected. It is recommended that further work be conducted to analyse the data, determine lane width requirements, and variations in tracking ability between separate trailers. The findings should be compared with Prem et al. (2000) and NRTC (2001) values. Further work is also required to identify which factors most influence lateral displacement of the rear trailer. It is expected that the research findings will be used to inform development of Queensland Department of Main Roads' Route Assessment Guidelines and potentially those of other authorities.

This dissertation investigates methods of real-time adaptive traffic signal control in the context of single isolated intersection and coordinated urban network applications. A primary goal in this dissertation is to identify and address scenarios where real-time optimized controllers do not maintain competitive performance with off-line calibrated, vehicle-actuated control techniques. An extensive literature review is supplemented by subsequent simulation experiments. Several strategies were implemented and evaluated, including OPAC, PRODYN, COP, ALLONS-D, Webster's optimized fixed-time control, and vehicle-actuated control. In particular, evaluation is based on simulation of a single, isolated intersection, where all algorithms are required to adopt the exact, deterministic traffic model used by the simulation. This approach eliminates confounding factors in comparison of algorithms, such as detector placement and disparate traffic models, focusing evaluation on the efficiency of the algorithms and their ultimate performance in terms of vehicle delay. A new algorithm is developed, employing neuro-dynamic programming techniques, also known as reinforcement learning techniques. Several very effective pruning strategies are also constructed. The final product is a very efficient algorithm capable of solving problems up to 2000 times faster than the most efficient previously published algorithm tested, with an 8% decrease in delay. This algorithm is then extended to a generalized, multi-ring control formulation. Simulation results with a standard dual-ring, eight-phase controller demonstrate that efficient, real-time solutions are achieved with a corresponding 12--22% reduction in delay relative to dual-ring, vehicle-actuated control. The real-time optimized, multi-ring controller is finally extended for urban network applications, expanding the objective function to consider downstream performance measures, and adopt standard, vehicle-actuated type coordination constraints. Control on an 8-intersection arterial is evaluated using a CORSIM simulation over a range of traffic conditions. Results are compared with TRANSYT optimized fixed-time control, coordinated vehicle-actuated control, and RHODES. Two regimes of control are revealed, where cyclic coordination constraints provide a significant benefit, and where they prevent more effective control. An adaptive coordination layer is prescribed as a unifying architecture with the potential of obtaining effective control under both regimes. The adaptive control layer specification is explicitly distinguished from existing algorithms, such as SCOOT, SCATS, and VFC-OPAC.

Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Civil and Environmental Engineering; and, Thesis (S.M.)--Massachusetts Institute of Technology, Sloan School of Management, Operations Research Center, 2003.
Includes bibliographical references (p. 129).
Most air traffic delay measures assess delays relative to schedule. Over the past decades, however, airline schedules have been adjusted to take into account airspace congestion and yield better on-time performance. In that context, delay measures that are using scheduled times as a benchmark are of very limited use in assessing airport and airspace system congestion, since delay has already been built into the schedule. The primary goal of this thesis is to develop a measure that will estimate "true" delays that are not sensitive to schedule adjustments. In order to calculate "true" delays, we compute the difference between the actual gate-to-gate time and a theoretical benchmark, the "baseline". The baseline time to be used is O-D specific and is defined here as the gate-to-gate time from origin to destination under optimal (non-congested) conditions. We choose the fifteenth percentile of reported statistics on gate-to-gate time as an estimator of the baseline. We then compute baseline times for 618 major O-D pairs. Using the baseline times, we compute "true delays" on these 618 O-D pairs and observe that they are about 40% to 60% larger than delays relative to schedule. We also develop two methods to attribute O-D delays to the origin and destination airports. Using these methods, we determine that airports incurred about 5 to 13 minutes of delay per operation in 2000, depending on the airport under consideration. Airport rankings according to "true" delays are compared to airport rankings obtained from OPSNET delay statistics. The comparison suggests that, although OPSNET statistics underestimate the magnitude of delays, they yield very comparable airport rankings and can therefore be used to rank airports with respect to congestion. Finally, we change perspective and look at the development of probabilistic models for designing flight schedules that minimize delays relative to schedule. We use the simple case of an airline scheduling an aircraft for a round trip to illustrate the complexities and uncertainties associated with optimal scheduling.
by Yasmine E. Alj.
S.M.

The UbuntuNet Alliance, a consortium of National Research and Education Networks (NRENs) runs an exclusive data network for education and research in east and southern Africa. Despite a high degree of route redundancy in the Alliance's topology, a large portion of Internet traffic between the NRENs is circuitously routed through Europe. This thesis proposes a performance-based strategy for dynamic ranking of inter-NREN paths to reduce latencies. The thesis makes two contributions: firstly, mapping Africa's inter-NREN topology and quantifying the extent and impact of circuitous routing; and, secondly, a dynamic traffic engineering scheme based on Software Defined Networking (SDN), Locator/Identifier Separation Protocol (LISP) and Reinforcement Learning. To quantify the extent and impact of circuitous routing among Africa's NRENs, active topology discovery was conducted. Traceroute results showed that up to 75% of traffic from African sources to African NRENs went through inter-continental routes and experienced much higher latencies than that of traffic routed within Africa. An efficient mechanism for topology discovery was implemented by incorporating prior knowledge of overlapping paths to minimize redundancy during measurements. Evaluation of the network probing mechanism showed a 47% reduction in packets required to complete measurements. An interactive geospatial topology visualization tool was designed to evaluate how NREN stakeholders could identify routes between NRENs. Usability evaluation showed that users were able to identify routes with an accuracy level of 68%. NRENs are faced with at least three problems to optimize traffic engineering, namely: how to discover alternate end-to-end paths; how to measure and monitor performance of different paths; and how to reconfigure alternate end-to-end paths. This work designed and evaluated a traffic engineering mechanism for dynamic discovery and configuration of alternate inter-NREN paths using SDN, LISP and Reinforcement Learning. A LISP/SDN based traffic engineering mechanism was designed to enable NRENs to dynamically rank alternate gateways. Emulation-based evaluation of the mechanism showed that dynamic path ranking was able to achieve 20% lower latencies compared to the default static path selection. SDN and Reinforcement Learning were used to enable dynamic packet forwarding in a multipath environment, through hop-by-hop ranking of alternate links based on latency and available bandwidth. The solution achieved minimum latencies with significant increases in aggregate throughput compared to static single path packet forwarding. Overall, this thesis provides evidence that integration of LISP, SDN and Reinforcement Learning, as well as ranking and dynamic configuration of paths could help Africa's NRENs to minimise latencies and to achieve better throughputs.

The role of walking in the development of healthy, livable communities is being increasingly recognized. In urban areas, intersections represent locations where different modes converge, and are often viewed as deterrents to walking. This is due to the unwarranted and often unnecessary delays imposed by signal timing policies for pedestrians and increased potential for conflicts. Traditional signal timing design prioritizes vehicles over pedestrians leading to undesirable consequences such as large delays and risky pedestrian behaviors. Pedestrians are accommodated in a manner that is designed to cause least interruption to the flow of motor vehicles. This lack of pedestrian accommodation at signalized intersections is the focus of this dissertation. Understanding pedestrian attitudes and perceptions is important because it offers insights into actual crossing behavior at signalized intersections. An intercept survey of 367 crossing pedestrians was undertaken at four signalized intersections in Portland, Oregon, and binary logistic regression models were constructed to quantify the impacts of demographics, trip characteristics and type of infrastructure on pedestrian perceptions and attitudes regarding delay, crossing time and motivators for crossing decisions. Safety was found to have a larger effect than compliance on the decision to cross the street. Pedestrians at recall intersections expressed higher satisfaction with delay than at actuated intersections. Novel methods to measure pedestrian delay using 2070 signal controllers and Voyage software were developed. These methods have been adopted by the City of Portland to record actuation trends and delays at various intersections. In the absence of demand data, pedestrian push button actuations can be considered as a proxy for crossing demand. The micro-simulation software VISSIM was used to analyze delays resulting from varying pedestrian and vehicle volumes on a network of three intersections in Portland, Oregon. From a pedestrian perspective, free operation was found to be always beneficial due to lower pedestrian delays. However, from a system wide perspective, free operation was found to be beneficial only under low-medium traffic conditions from an overall delay reduction viewpoint, while coordinated operation showed benefits under heavy traffic conditions, irrespective of the volume of pedestrians. Control strategies were developed to identify the best mode of signal controller operation that produced the lowest overall average delay per user. A procedure to identify the optimal control strategy based on user inputs (major street volume to capacity ratios and rate of pedestrian phase serviced for the minor street) was developed. The procedure was applied to a network of three intersections in east Portland, OR and the findings were verified. This research offers significant contributions in the field of pedestrian research. The findings related to attitudes and perceptions of crossing pedestrians offer greater insights into pedestrian crossing behavior and add to the body of existing literature. The methods developed to obtain pedestrian actuations and delay data from signal controllers represent an easy and cost-effective way to characterize pedestrian service at intersections. The results pertaining to signal timing strategies represent an important step towards incorporating pedestrian needs at intersections and demonstrate how control strategies employed to benefit pedestrians could benefit the entire system.

Designers of mass produced products require knowledge about anticipated users of their designs in order to make reasonable predictions about how users will interact with a product and how that product will satisfy users??? needs. However, there is little reported study of how industrial designers get the information they need about users, or to what extent they adapt and use information available from fields of study such as ergonomics or market research. Study in this area is important, in order to have a knowledge base that will support development of methods and data sources that may help designers and others bring a better understanding of users into the product design process. In this study, group interviews and a questionnaire were used to ask industrial designers how and where they get information about users, and about their perceptions of the role and value of user research in design. The group discussions involved a total of 45 participants from nine companies in Sydney. A questionnaire that followed was completed by 35 respondents representing at least 15 different design consultancy companies throughout Australia. Results showed that the designers surveyed used many of the methods promoted in the literature of ergonomics, design and market research, but often in a cut-down form. For example, there was widespread use of work colleagues and family members as test subjects. Designers used quantitative information where it was applicable but often sought qualitative information that would provide insights or enable them to develop empathic understanding of the users. Time and cost constraints limited the extent to which designers could engage in user research activity but there was general agreement that user research was a necessary part of design and that in the future designers will require a stronger capability in user research. Further research could focus on the evaluation of user research methods used in design and the potential for further collaboration between designers and other specialists in this area.

The deployment of third generation (3G) cellular systems is resulting in a transition from cellular systems that predominantly carry constant-bit-rate (CBR) voice traffic to multi-service packet based systems that predominantly carry variable-bit-rate (VBR) traffic. With 3G DS-CDMA cellular systems there is a direct relationship between user traffic and propagation dependent performance as additional traffic causes increased system interference. This thesis investigates the impact of VBR traffic on the propagation dependent performance of DS-CDMA cellular systems that utilise frame-by-frame dynamic resource allocation on the radio channel. A DS-CDMA cellular system model is developed and the downlink performance of both outdoor macro-cellular and indoor pico-cellular systems is evaluated with a variety of traffic types. Both traffic scheduling performance and propagation dependent performance are evaluated as the two are inter-linked. Scenarios are identified where propagation dependent performance is sensitive to the statistical properties of the user traffic streams and it is shown that a significant performance difference potentially exists between different traffic types when the number of users per cell is low. When a significant performance difference does exist, burstier more variable traffic generally results in superior propagation dependent performance. The base transceiver station (BTS) transmitter power mean and variance provides a good indication of the level of propagation dependent performance regardless of the specific traffic type. Traffic scheduling policies that deliberately reduce the variability of user traffic streams are considered and in terms of propagation dependent performance these are shown to have a minimal impact on the performance difference between different traffic types. The implications of VBR traffic on DS-CDMA cellular system design are outlined and it is shown that VBR traffic can be approximated as CBR traffic in many scenarios and this is a convenient approximation as it simplifies system design and detailed traffic models do not need to be developed.

Traffic and parking congestion are significant issues at many universities nationwide. The delays experienced result in wasted time, money, and fuel for students, faculty and staff, not to mention the negative contributions to the environment. This paper quantifies the amount of vehicle emissions generated during an average morning peak hour in the university environment. Using VISSIM and CMEM microsimulation packages, a model is created for California Polytechnic State University- San Luis Obispo to aggregate the collective transportation behaviors and practices of the campus and recognize the implications these behaviors pose on the transportation network as a whole. Reasonable estimates are generated for overall HC, CO, and NOx type emissions as well as fuel consumption. Scenarios are proposed which reflect the sensitivity of outputs to key input parameters. The findings of this research can be useful for future campus planning and the ideas can be extended to similar environments with traffic and parking problems such as business parks, corporate campuses, downtown districts, and special event venues.

New dynamic signal control methods such as fuzzy logic and artificial intelligence developed recently mainly focused on isolated intersection. In this study, a Fuzzy Logic Control for a Diamond Interchange incorporating with Fuzzy Ramp System (FLDI) has been developed. The signalization of two closely spaced intersections in a diamond interchange is a complicated problem that includes both increasing the diamond interchange capacity and reduce delays at the same time. The model comprises of three main modules. The Fuzzy Phase Timing module controls the current phase green time extension, the Phase Selection module select the next phase based on the pre-defined phase sequence or phase logics and the Fuzzy Ramp module determines the cycle time of the ramp meter bases on current traffic volumes and conditions of the interchanges and the motorways. The developed FLDI model has been compared with the traffic actuated simulation with respects to flow rates and the average delays of the vehicles. The model of an actual diamond interchange is described and simulated by using AIMSUN (Advanced Interactive Microscopic Simulator for Urban and Non-Urban Network) software. Simulation results show the FLDI model outperformed the traffic actuated models with lower system total travel time, average delay and improvements in downstream average speed and average delay.

Location â allocation models are designed to seek the concurrent location of a set of service facilities and an allocation scheme to satisfy the demands of a set of customers or users of a given system. If the locationâ allocation model is based on a graph-theoretic formulation, then the demand-fulfilling items will move from a designated origin or origins, through arcs and transshipment nodes, to a set of destinations selected by the model. It is suggested in this research effort that such a modeling structure may be employed to simulate transportation evacuation conditions that may arise in the case of a natural disaster, namely a hurricane. A nonlinear mixed integer mathematical program is formulated to route passengers in automobiles on paths in the transportation network, such that the endangered area is evacuated in the minimum amount of time. One heuristic and two exact, convergent, implicit enumeration algorithms based on the generalized Benders' decomposition method are presented. The algorithms are designed to exploit the inherent problem structure. Computational experience is provided against a set of realistic test problems formulated on the Virginia Beach network. Potential avenues for further research are also explored.

Master of Science

Ramp metering, one of the most effective solutions for improving motorway traffic flows, is playing increasingly important role in traffic management systems. Because of its capability to handle nonlinear and non-stationary problems, fuzzy logic based ramp metering algorithms have been always considered as an extremely suitable control measures to handle a complex nonlinear traffic system. This thesis proposes a genetic fuzzy approach to design a traffic-responsive ramp control algorithm for an isolated onramp. For a local ramp meter algorithm, the problem could be described as the inflow optimization of on-ramp, based on the evaluation of motorway traffic condition. If the inflow of on-ramp is considered as the decision variable, the ramp control problem could be treated as a nonlinear optimization problem of maximizing the evaluation function. The adaptive genetic fuzzy approach is actually a control approach to maximize the inflow of on-ramp under the restriction of evaluation function. In this thesis, a well-known fuzzy logic based ramp metering algorithms developed by Bogenberger is introduced and implemented with an on-ramp congestion model of Constellation Drive Interchange in a stochastic microscopic traffic simulator, Aimsun. To improve the performance of fuzzy control system, genetic algorithm is applied to tune the parameterized membership function of each fuzzy input to maintain the flow density of motorway blow the estimated congestion density. The performances of the genetic fuzzy logic control ramp metering are compared with FLC (fuzzy logic control) ramp metering by means of the percentage change of TTT (Total Travel Time) based on no control condition in Aimsun. The simulation results show the genetic fuzzy ramp metering has a more significant improvement on TTT and more strong stability to maintain system flow density than FLC ramp metering.

Crashes resulting from automobiles running a red light are typically severe in nature. One way to try to reduce the number and severity of these types of crashes is by increasing the red clearance interval of a traffic signal. In Portland, Oregon, eight intersections received a variety of treatments including red extensions. Determining which treatment had what effect can be difficult to weed out. Using a combination of crash analysis and a model simulating an intersection with red extensions, this paper describes the estimated impact of red light running intersection upgrades and red extensions on crashes. By performing a variety of before and after crash analysis, a reduction of angle crashes after treatments was detected, with a crash modification factor of 0.64 +/- 0.28 using the Empirical-Bayes method. Output from the simple simulation also suggest that red light running crashes can be reduced with red extension technology and confirms crash modification values determined from the Empirical-Bayes method.

Hazardous materials are substances that, if not regulated, can pose a threat to human populations and their environmental health, safety or property when transported in commerce. About 1.5 million tons of hazardous material shipments are transported by truck in the US annually, with a steady increase of approximately 5% per year. The objective of this study was to develop a routing tool for hazardous material transport in order to facilitate reduced environmental impacts and less transportation difficulties, yet would also find paths that were still compelling for the shipping carriers as a matter of trucking cost. The study started with identification of inhalation hazard impact zones and explosion protective areas around the location of hypothetical hazardous material releases, considering different parameters (i.e., chemicals characteristics, release quantities, atmospheric condition, etc.). Results showed that depending on the quantity of release, chemical, and atmospheric stability (a function of wind speed, meteorology, sky cover, time and location of accidents, etc.) the consequence of these incidents can differ. The study was extended by selection of other evaluation criteria for further investigation because health risk as an evaluation criterion would not be the only concern in selection of routes. Transportation difficulties (i.e., road blockage and congestion) were incorporated as important factor due to their indirect impact/cost on the users of transportation networks. Trucking costs were also considered as one of the primary criteria in selection of hazardous material paths; otherwise the suggested routes would have not been convincing for the shipping companies. The last but not least criterion was proximity of public places to the routes. The approach evolved from a simple framework to a complicated and efficient GIS-based tool able to investigate transportation networks of any given study area, and capable of generating best routing options for cargos. The suggested tool uses a multi-criteria-decision-making method, which considers the priorities of the decision makers in choosing the cargo routes. Comparison of the routing options based on each criterion and also the overall suitableness of the path in regards to all the criteria (using a multi-criteria-decision-making method) showed that using similar tools as the one proposed by this study can provide decision makers insights in the area of hazardous material transport. This tool shows the probable consequences of considering each path in a very easily understandable way; in the formats of maps and tables, which makes the tradeoffs of costs and risks considerably simpler, as in some cases slightly compromising on trucking cost may drastically decrease the probable health risk and/or traffic difficulties. This will not only be rewarding to the community by making cities safer places to live, but also can be beneficial to shipping companies by allowing them to advertise as environmental friendly conveyors.

Reforms to the national research and research training system by the Commonwealth Government of Australia sought to effectively connect research conducted in universities to Australia's national innovation system. Research training has a key role in ensuring an adequate supply of highly skilled people for the national innovation system. During their studies, research students produce and disseminate a massive amount of new knowledge. Prior to this study, there was no research that examined the contribution of research training to Australia's national innovation system despite the existence of policy initiatives aiming to enhance this contribution. Given Australia's below average (but improving) innovation performance compared to other OECD countries, the inclusion of Finland and the United States provided further insights into the key research question. This study examined three obvious ways that research training contributes to the national innovation systems in the three countries: the international mobility and migration of research students and graduates, knowledge production and distribution by research students, and the impact of research training as advanced human capital formation on economic growth. Findings have informed the concept of a research training culture of innovation that aims to enhance the contribution of research training to Australia's national innovation system. Key features include internationally competitive research and research training environments; research training programs that equip students with economically-relevant knowledge and the capabilities required by employers operating in knowledge-based economies; attractive research careers in different sectors; a national commitment to R&D as indicated by high levels of gross and business R&D expenditure; high private and social rates of return from research training; and the horizontal coordination of key organisations that create policy for, and/or invest in research training.

Rising from the “excess demand” modern societies and economies place on limited road resources, congestion causes increased vehicle emissions, decreases national efficiency, and wastes time (Downs, 2004). In order to minimise congestion’s impacts, traffic management systems gather traffic data and use it to implement efficient management algorithms (Downs, 2004). This dissertation’s purpose has been the development of a distributable vehicle presence detection sensor, which will wirelessly provide vehicle presence information in real time. To address the sensor’s wireless power requirements, the feasibility of self-powering the device via harvested energy has been investigated. Piezoelectric, electrostatic, and electromagnetic energy harvesting devices’ principles of operation and underlying theory has been investigated in detail and an overview presented alongside a literature review of previous vibration energy harvesting research. An electromagnetic energy harvesting device was designed, which consists of: a nylon reinforced rubber bladder, hydraulic piston, neodymium magnets, and wire-wound coil housing. Preliminary testing demonstrated a harvested energy between 100mJ and 205mJ per axle. This amount is able to be transferred to a 100O load when driven over at speeds between 10km/h and 50km/h. Combined with an embedded circuit, the energy harvester facilitated the development of a passive sensor, which is able to wirelessly transmit a vehicle’s presence signal to a host computer. The vehicle detected event is displayed via a graphical user interface. Energy harvesting’s ability to power the embedded circuit’s wireless transmission, demonstrated the feasibility of developing systems capable of harvesting energy from their environment and using it to power discrete electronic components. The ability to wirelessly transmit a vehicle’s presence facilitates the development of distributable traffic monitoring systems, allowing for remote traffic monitoring and management.

This dissertation develops, presents and tests a new international tool, the so-called Road Safety Development Index (RSDI), which indicates in a comprehensive and easy way the severity of the road safety situation in a specific country and/or in comparison with other countries. There are three pillars of outcomes involved in the framework of RSDI. One pillar is the People focus (road user behaviour). The second is the System focus (safer vehicles, safer roads, enforcement, management, etc). The third is the Product focus in terms of accident death rates. This thesis analyses each of these pillars. In addition, RSDI links the key national practices of road safety to each other and to the end-results (accident death rates). The study suggests a master-list of performance indicators to be implemented for assessing road safety level in a country and for RSDI building. Based on the “master-list”, a short key list of performance indicators is chosen and classified into two primary categories that correspond to two groups of countries: LMCs “Less Motorised Countries” and HMCs “Highly Motorised Countries”. RSDI aggregates the key performance indicators into one single quantitative value (composite index). Four main objective and subjective approaches are used to calculate RSDI and determine which one is the best. One approach uses equal weights for all indicators and countries, whereas the other approaches give different weights depending on the importance of indicators. Two empirical studies were carried out, in different parts of the world, to determine the applicability of this tool in real world applications. The first empirical study comes from eight European countries (HMCs). The second empirical study comes from five Southeast Asian countries (LMCs). The RSDI results from this study indicate a remarkable difference between the selected countries even at the same level of motorisation and/or with close accident death rates. The unavailability of comparable and useful data are problems for deeper analysis of RSDI, especially the index should be as relevant as possible for different parts of the world. The empirical and theoretical assessments prove that RSDI can give a broader picture of the whole road safety situation in a country compared to the traditional models and can offer a simple and easily understandable tool to national policy makers and public.
Denna avhandling utvecklar, presenterar och testar ett nytt internationellt verktyg, det så kallade Road Safety Development Index (RSDI), vilket på ett begripligt och lättillgängligt sätt beskriver trafiksäkerhetsläget i ett visst land jämfört med andra länder. Resultatet av RSDI utgörs av tre grundpelare. Den första pelaren är Fokus på människor (vägtrafikbeteende). Den andra är Fokus på systemet (säkrare fordon, säkrare vägar, beivrande, management, osv). Den tredje pelaren är Fokus på produkten med avseende på antal döda per fordon och per invånare. Arbetet analyserar var och en av dessa tre pelare. RSDI kopplar dessutom samman de viktigaste nationella praxisarna och erfarenheterna med varandra och till slutresultaten (antal dödsfall). Studien föreslår en lista med de viktigaste indikatorerna på hur olika länder vidtar åtgärder för trafiksäkerheten. Grundat på denna “master-lista” kan en kort lista med de viktigaste indikatorerna skapas och klassificeras i två huvudkategorier för två typer av länder: LMC “länder med låg andel fordon” och HMC “länder med hög andel fordon”. RSDI aggregerar de viktigaste performance-indikatorerna till ett enda kvantitativt mått (ett sammansatt index). Fyra olika objektiva och subjektiva huvudangreppssätt används för att beräkna RSDI och bestämma vilket av dem som är det bästa. En metod använder sig av lika stora vikter för alla indikatorer och länder, medan en annan metod ger olika vikter beroende på indikatorernas betydelse. Två empiriska studier genomfördes i olika delar av världen för att bestämma tillämpligheten av detta verktyg i verkliga situationer. Den första empiriska studien kommer från åtta länder i Europa (HMC-länder). Den andra empiriska studien har gjorts i fem länder i Sydostasien (LMC-länder). Resultaten från detta RSDI tyder på en anmärkningsvärd skillnad mellan de valda länderna, också om andelen bilägare och/eller andra variabler för trafiksäkerhet hålls konstanta. Bristen på jämförbara och användbara data medför problem vid en djupare analys av RSDI för olika delar av världen. De empiriska och teoretiska skattningarna visar att RSDI kan ge en bredare bild av hela trafiksäkerhetssituationen i ett land jämfört med traditionella modeller och kan erbjuda ett enkelt och lättförståeligt verktyg för de nationella beslutsfattarna liksom för allmänheten.

Reforms to the national research and research training system by the Commonwealth Government of Australia sought to effectively connect research conducted in universities to Australia's national innovation system. Research training has a key role in ensuring an adequate supply of highly skilled people for the national innovation system. During their studies, research students produce and disseminate a massive amount of new knowledge. Prior to this study, there was no research that examined the contribution of research training to Australia's national innovation system despite the existence of policy initiatives aiming to enhance this contribution. Given Australia's below average (but improving) innovation performance compared to other OECD countries, the inclusion of Finland and the United States provided further insights into the key research question. This study examined three obvious ways that research training contributes to the national innovation systems in the three countries: the international mobility and migration of research students and graduates, knowledge production and distribution by research students, and the impact of research training as advanced human capital formation on economic growth. Findings have informed the concept of a research training culture of innovation that aims to enhance the contribution of research training to Australia's national innovation system. Key features include internationally competitive research and research training environments; research training programs that equip students with economically-relevant knowledge and the capabilities required by employers operating in knowledge-based economies; attractive research careers in different sectors; a national commitment to R&D as indicated by high levels of gross and business R&D expenditure; high private and social rates of return from research training; and the horizontal coordination of key organisations that create policy for, and/or invest in research training.

Thesis (MScEng)--Stellenbosch University, 2013.
ENGLISH ABSTRACT: Road traffic accidents have been a global concern facing all countries. Approximately 1.2 million people are killed annually as a result of traffic accidents and 50 million are injured. More than 90 percent of road fatalities occur in the developing world which has only 48 percent of the world’s registered vehicles. Beyond the problem of road fatalities, road traffic accidents result in disability and long term injury. They also cause considerable economic losses to victims and their families and damage properties and infrastructures. In South Africa, pedestrian fatalities account for about 40 percent of all road traffic accidents. Behaviour patterns of both pedestrians and motorists at pedestrian crossings are the main influential factors of pedestrian accidents. This study investigates behaviour patterns of pedestrians negotiating different types of crossing facilities in the town of Stellenbosch, in South Africa. A total number of 17 pedestrian crossings were selected for the study on the basis of their geometric and operational characteristics. Video-based observations together with on-street interviews were used to understand crossing behaviour patterns, namely pedestrian walking speed, pedestrian delay, gaze behaviour, pedestrian-vehicle conflicts, pedestrian compliance with road traffic rules and gap-acceptance behaviour. Results of the study showed that male pedestrians walk more than female pedestrians. The 15th percentile crossing speed for all pedestrians observed while crossing was found to be 1.13 m/s whereas the mean crossing speed was found to be 1.48 m/s. Demographic variables appeared to significantly influence pedestrian walking speed. Male and younger pedestrians exhibited higher walking speeds than female and older pedestrians. Pedestrian walking speed was also found to be affected by group size, encumbrance, type of pedestrian facility and distraction while walking. However, no effects of conflicts and the presence of a pedestrian refuge on pedestrian walking speed were found in this study. A mean total delay of 5.10 seconds was found in this study. Male and younger pedestrians experienced shorter delay compared to female and older pedestrians. The type of pedestrian facility and traffic signals during which pedestrians arrived at the kerb and crossed appeared to be other influential factors of pedestrian delay. With regard to gaze behaviour, an average number of head movements ranged from 2 to 5 at the kerb and from 3 to 5 while crossing. Conflicts with motorists peaked where crossing distances were longer and traffic volume was heavy. A red light violation ranging from 82 to 87 percent was observed in this study and on-street surveys indicated that beliefs and attitudes towards traffic control devices and traffic environment significantly explained pedestrians’ unsafe crossing behaviour. The calculated critical gap and critical lag ranged from 2.19 to 3.90 seconds and the effect of crossing distance on gap-acceptance emerged in this study. Possible interventions are finally suggested.
AFRIKAANSE OPSOMMING: Padongelukke is 'n wêreldwye probleem wat al die lande in die gesig staar. Ongeveer 1,2 miljoen mense sterf jaarliks as 'n gevolg van verkeersongelukke en 50 miljoen word beseer. Meer as 90 persent van padsterftes kom voor in die ontwikkelende wêreld met slegs 48 persent van die wêreld se geregistreerde voertuie. Bo en behalwe die probleem van padsterftes, het padongelukke gestremdheid en lang termyn beserings tot gevolg. Dit veroorsaak ook aansienlike ekonomiese verliese vir die slagoffers en hul gesinne en skade aan eiendomme en infrastruktuur. In Suid-Afrika is voetgangersterftes verantwoordelik vir sowat 40% van alle padongelukke. Gedragspatrone van beide voetgangers en motoriste by voetoorgange is die belangrikste bepalende faktore van voetganger-ongelukke. Hierdie studie ondersoek gedragspatrone van voetgangers by verskillende tipes kruisings in die dorp van Stellenbosch Suid-Afrika. ʼn Totale aantal van 17 voetoorgange is gekies vir die studie op die basis van hul geometriese en operasionele eienskappe. Video-gebaseerde waarnemings saam met op-straat onderhoude is gebruik om kruising-gedragspatrone, naamlik voetganger stapspoed, voetganger vertraging, kyk gedrag, voetganger-voertuig konflikte, voetganger nakoming van padverkeersreëls en gaping-aanvaarding gedrag te verstaan. Resultate van die studie het getoon dat manlike voetgangers vinniger loop as vroulike voetgangers. Die 15de persentiel kruising spoed vir alle voetgangers waargeneem binne kruisings was 1,13 m/s, terwyl die gemiddelde kruising spoed 1,48 m/s is. Demografiese veranderlikes beïnvloed voetgangers loop-spoed. Manlik en jonger voetgangers loop vinniger as vroulike en ouer voetgangers. Voetgangers loop-spoed word ook geraak deur die grootte van die groep, die dra van items, die tipe voetganger-fasiliteit en afleiding terwyl geloop word. Daar is egter geen gevolge van konflikte op voetgangers loop-spoed in hierdie studie gevind nie. 'n Gemiddelde totale vertraging van 5,10 sekondes is in hierdie studie gevind. Manlik en jonger voetgangers ervaar korter vertraging in vergelyking met die vroulike en ouer voetgangers. Die tipe voetgangerfasiliteit en verkeerseine was ander invloedryke faktore van voetganger vertraging. Vir waarneming van die verkeer is gevind dat die gemiddelde aantal kopbewegings gewissel het van 2 tot 5 teen die randsteen en van 3 tot 5, tydens die kruising. Konflikte met motoriste het ʼn hoogtepunt bereik waar kruising afstande langer en verkeersvolume hoër was. Rooi lig oortredings wat wissel van 82 tot 87 persent is in hierdie studie waargeneem en op-straat opnames het aangedui dat houdings teenoor verkeer-beheer toestelle en die verkeersomgewing die voetgangers se onveilige kruising-gedrag verduidelik. Die berekende kritiese gaping het gewissel van 2,19 tot 3,90 sekondes en die effek van die kruisinglengte op gaping-aanvaarding het in hierdie studie na vore gekom. Moontlike intervensies word voorgestel.

Thesis (PhD)--Stellenbosch University, 2012.
ENGLISH ABSTRACT: The design of railway station environments in South Africa and to a certain extent internationally, is based on rules of thumb. These rules, using general macroscopic principles for determining peak passenger loads are inadequate and misleading for detailed design purposes. The principles advocated in local design guideline documents are erroneous and ignore the highly variable flow nature or “micro-peaking” effects that typically occur within railway station environments. Furthermore, there are no procedures proposed in these guideline documents, which leads to ambiguous assessment techniques used by practitioners in the determination of pedestrian spatial areas. It is evident that the knowledge in the area of pedestrian movement contained within the design guidance is far from comprehensive. Without a reliable method for estimating pedestrian levels-of-service and capacities, design of new facilities does not follow a uniform process, resulting in high levels of uncertainty in determining if the time, money and resources invested in upgrading facilities will actually cater to the demand. The situation is further exacerbated by current industry thinking towards pedestrian modelling in South Africa, where it is perceived by both clients and practitioners to be more cost effective to use macroscopic techniques and designing infrastructure according to a “one-level-up” level-of-service method. Working with architects confirmed that the area of circulation design was lacking in data and guidance and that associated quantified assessments of pedestrian movement was rarely, if ever, carried out. Towards addressing these issues, the development of a Spatial Parameter (SP)-model spreadsheet application became the main objective of the study. The model contributes towards addressing the needs of individual station users based on the trade-off between level-of-service and infrastructure costs. The output of the model allows the designer to avoid the under-provision (detrimental to operations) and oversizing of railway station infrastructure (with obvious financial implications). The author recognised the lack of pedestrian movement data in South Africa and addressed this by conducting extensive video-based pedestrian observations aimed at exploring the macroscopic fundamental relationships and the ways in which these relationships might be influenced by the various personal, situational and environmental factors that characterise the context in which pedestrians move. The movement trajectories of 24,410 pedestrians were investigated over three infrastructure environments at Maitland and Bonteheuwel stations in Cape Town, carefully selected to incorporate the cultural diversity common in South Africa. Tracking of pedestrians was achieved via the use of an in-house developed “video annotator” software tool. Boarding and alighting rates of 7,426 passengers were also observed at these stations incorporating contributory attributes such as age, gender, body size, encumbrance, group size, time of day, and location. The research makes a number of significant advances in the understanding of pedestrian flow behaviour within railway station environments and provides recommendations to industry of what issues to consider. The empirical study has provided comprehensive pedestrian movement characteristics incorporating the relationships between density, speed and flow including the effect of culture and other context factors unique to the local South African environment. New methods for determining spatial requirements are proposed, together with new and unique empirical data for use by the local industry. A calibrated spreadsheet SP-model for assessing the design of concourse type railway stations is developed and presented in the study. The advance in local pedestrian flow knowledge, together with the SP-model, is shown to be practical through application to two real railway station case study projects. The results of this study constitute an important contribution to local pedestrian flow knowledge and is considered a valuable resource for those developing pedestrian models in practice. It is expected that the results will be useful in the planning and design of pedestrian environments in South African railway stations and can be applied to other African metro railway stations with similar pedestrian characteristics. Overall, this research has succeeded in advancing the approach to railway station design, empirical data, knowledge and methods held within the local engineering industry. However, the contribution of this study and associated conference papers is an early step in changing the perceptions in this country towards ensuring fully informed and appropriate performance-based spatial designs.
AFRIKAANSE OPSOMMING: Die ontwerp van areas binne Suid-Afrikaanse spoorweg stasies en ook tot ‘n sekere mate internasionaal, is gebaseer op historiese ondervindings asook riglyne wat tans in die praktyk gebruik word. Die riglyne gebruik algemene makroskopiese beginsels om die spits passasiersvrag te bepaal vir gedetaileerde ontwerp doeleindes. Hierdie riglyne is egter ongeskik en misleidend aangesien dit nie die hoogs wispelturige natuur van vloei en mikrospits effekte wat binne die stasies plaasvind, in ag nie. Die riglyne ontbreek ook van prosedures wat gevolg moet word vir die bepaling van ruimtelike areas vir voetgangers wat die gevolg het dat dubbelsinnige beramingstegnieke deur praktisyne gebruik word. Die kennis oor voetganger bewegings in die ontwerp riglyne is nie omvattend genoeg nie. Sonder ‘n betroubare beramings metode vir die bepaling van voetganger diensvlak en kapasiteit kan daar nie bepaal word of die tyd, geld en hulpbronne wat in die fasilitieit geinvesteer word, aan die behoeftes gaan voldoen nie. Die situasie word verder vererger deur die huidige persepsie oor voetganger modellering in Suid-Afrika, waar dit deur beide kliënte en praktisyne, as ‘n meer koste effektiewe oplossing gesien word om makroskopiese tegnieke te gebruik en om infrastruktuur te ontwerp volgens ‘n metode waar ‘n hoër diensvlak as die teiken diensvlak gebruik word. In samewerking met argitekte is dit bevestig dat die area van sirkulasie ontwerp ‘n tekort het aan data en riglyne en dat die kwantitatiewe skattings verbonde aan voetganger beweging selde, indien ooit, uitgevoer word. Die ontwikkeling van ‘n Spatial Parameters (SP)-model om die bogenoemde problem te oorkom, is die hoofdoel van hierdie tesis. Die model poog om die behoeftes van individuele stasie gebruikers aan te spreek gebaseer op die wisselwerking tussen diensvlak en infrastruktuur kostes. Die uitsette van die model stel die ontwerper in staat om ondervoorsiening en oorvoorsiening van spoorweg stasie infrastruktuur te voorkom wat nadelige vir die bedryf is en ook ooglopende finansiële implikasies tot gevolg het. Die skrywer het die tekort aan data aangaande voetganger bewegings in Suid-Afrika geidentifiseer en dit aangespreek deur omvattende video gebaseerde voetganger waarnemings te maak met die doel om die basiese makroskopiese verhoudings te ondersoek asook in hoe ‘n mate hierdie verhoudings beinvloed word deur verskeie persoonlike, liggings- en omgewingsfaktore wat die konteks waarin voetgangers beweeg, karakteriseer. Die bewegingsprofiel van 24,410 voetgangers is ondersoek by drie infrastruktuur omgewings by Maitland en Bonteheuwel stasies in Kaapstad. Die stasies is noukeurig uitgesoek om Suid-Afrika se kulturele diversiteit te verteenwoordig. Die voetgangers is nagevolg deur gebruik te maak van ‘n selfontwikkelde video-annoteerder sagteware. Waarneming van die opklim- en afklimspoed van 7,426 passasiers is gemaak by hierdie stasies en faktore soos ouderdom, geslag, liggaamsgrootte, mobiliteit, grootte van groepe, tyd van die dag en ligging was ingesluit by die waarnemings. Hierdie navorsing maak belangrike bydraes tot die begrip van die vloei van voetgangers binne spoorweg stasies en aanbevellings word aan die industrie gemaak oor die faktore wat in ag geneem moet word by ontwerp van fasilitieite. Die empiriese studie het omvattende voetganger beweging karakteristieke uitgewys wat die verhoudings tussen digtheid, spoed en vloei inkorporeer asook die effek van kultuur en ander faktore wat verband hou met die unieke konteks van die plaaslike Suid-Afrikaanse omgewing. Nuwe metodes om ruimtelike-vereistes te bepaal word voorgestel, saam met nuwe en unieke empiriese data vir gebruik deur die plaaslike industrie. ‘n Gekalibreerde en gevalideerde SP-model is ontwikkel om die ontwerp van spoorweg stasies te assesseer en word in hierdie tesis beskyf en aangebied. Die studie toon dat akkurate data en kennis oor plaaslike voetganger vloei met die SP-model verkry kan word, soos bewys uit twee spoorweg stasie studiegevalle. Die resultate van hierdie tesis dien as ‘n belangrike bydrae tot die kennis van plaaslike voetganger vloei en word geag as ‘n waardevolle hulpbron vir die ontwikkeling van voetganger modelle in die praktyk. Hierdie resultate mag nuttig wees gedurende die beplanning en ontwerp van voetganger-areas in Suid-Afrikaanse spoorweg stasies. Dit kan ook toegepas word vir spoorweg stasies in die res van Afrika wat soortgelyke voetganger karaktereienskappe het. Die navorsing het daarin geslaag om die benadering tot spoorweg stasie ontwerp te verbeter, asook om empiriese data, kennis en die metodes wat binne die plaaslike ingenieurs industrie voorgehou word, te verbeter. Let egter daarop dat die bydrae wat hierdie tesis maak, asook bydraes deur relevante konferensie verhandelinge, ‘n vroeë stap is in die verandering van persepsies in Suid-Afrika om geskikte prestasie-gebaseerde ruimte ontwerpe te verseker.

In my previous bachelor's thesis I studied an algorithm for the improvement of runway efficiency in normal condition: minimizing the occupation of the runway means serving the greatest number of aircraft with the least possible delay. But other important limitations of airports are the ones in force during low visibility when the number of movements allowed undergoes a relevant reduction. A solution could be the use of technology to support air traffic controllers and pilots to re-establish a good level of situational awareness in order to reduce the limitations in force. In Europe, the technological pillar of the ambitious Single European Sky initiative is the Single European Sky ATM Research project (SESAR). Inside the SESAR project, the RETINA concept is regarding the introduction of augmented reality in aerodrome control tower for the improvement of efficiency and capacity of airports. Within the RETINA concept this thesis aims to study the implementation of new safety nets for aerodrome control tower with the support of augmented reality. This study starts from introduction to air traffic services in order to focus on SESAR project and RETINA concept. Then, concept and graphical solution for Conflicting ATC Clearances Safety Net (CATC) are proposed. Due to Covid-19 pandemic in progress during the thesis work, the implementation and validation activities could not be carried out in RETINA simulator of the University of Bologna labs, so different stand-alone implementation in Unity and validation by questionnaire administered to air traffic controllers are used. This thesis work can be considered as the first iteration in the User-Centered Design process for CATC. After the analysis of the feedback, new iteration in which the design is driven and refined by user-centered evaluation could be setup.

Au cours des dernieres decennies, la demande de trafic au niveau des aeroports a augmente regulierement a tel point que le trafic au sol est devenu critique pour la securite et l'efficacite des operations aeroportuaires. Cette these propose une approche a deux niveaux pour l'analyse et l'optimisation du trafic avion au sol sur les aeroports. Elle est divisee en trois parties: - La premiere partie introduit la problematique generale et son environnement - La deuxieme partie traite la gestion a moyen terme du trafic au sol des avions. Une approche globale pour estimer la capacite theorique et la capacite pratique du trafic avion est proposee. Celle-ci met en Suvre une approche d'optimisation du flux dans un reseau qui conduit a la formulation de differents problemes de programmation mathematique - La troisieme partie traite du niveau tactique et une approche adaptative est developpee pour definir les routes et les horaires associes aux mouvement d'arrivee ou de depart des avions. Une approche de resolution operationnelle est alors proposee.

International organisations such as the World Health Organisation highlight the road crash problem in less motorised (or developing, or low income) countries like those in Southeast Asia and recommend the adoption of Western road safety measures. However, there are many differences between highly motorised and less motorised countries which raise questions about how successfully Western road safety knowledge and expertise can be transferred.----- A review of the statistical information on road crashes shows a great deal of uncertainty about both the scale and likely trajectory of road fatalities globally, in less motorised countries and in Asia. It is generally agreed, however, that Asia accounts for around half of all road fatalities, and analysis of the limited available data shows both that Southeast Asia is not an atypical region of Asia in road safety terms, and that Thailand and Vietnam are not atypical of Southeast Asian countries.----- A literature review of recommended practice approaches to road safety transfer in Asia shows that there are many economic, institutional, social and cultural factors which potentially influence the success of transfer. The review also shows that there is no coherent, comprehensive approach which either conceptualises these factors and their relationship to transfer outcomes, or uses an analysis of these factors to plan or modify transfer. To address this gap, this thesis develops a 'road safety space' model as a tool for conceptualisation and analysis, based on a biological metaphor which views the transfer of road safety measures from one context to another as analogous to the transfer of a species into a new ecological space. The road safety space model explicitly considers economic, institutional, social and cultural factors (from specific to broad) which influence the particular road safety issue which a particular road safety transfer effort seeks to address. A central contention of this thesis is that the road safety space model is both a feasible and useful tool to improve the process of road safety transfer to less motorised countries. Road safety space analysis is seen to have a role in a broader process of selection of road safety measures for transfer, along with knowledge of how the measures are considered to operate.----- The research reported in this thesis is comprised of three studies. Study 1 reviewed evaluations of road safety transfer to Thailand and Vietnam. Studies 2 and 3 were case studies of road safety transfer to Thailand and Vietnam respectively.----- Study 1 was an analysis of existing evaluations of road safety transfer to Thailand and Vietnam. The aims were to analyse the evaluations for their consideration of contextual factors, as described in the road safety space model, and to discuss whether the road safety space model assisted in understanding the reasons for success or failure of transfer. However, very few such evaluations exist, and those that were found generally lacked information on whether contextual factors were considered. This indicated the need for a more detailed, in-depth qualitative investigation of particular cases of road safety transfer, in order to investigate the feasibility and utility of the road safety space model.----- Two case studies (Study 2 and Study 3) were conducted to test whether the road safety space approach was both feasible and useful as a means of improving road safety transfer efforts. Study 2 was a case study of the development and implementation in Thailand of a road safety education program for school children, which involved the transfer of Western research and techniques. The transfer agents (i.e. those who effected the road safety transfer) were Australian consultants working for the Australian Road Research Board (ARRB). The transfer was funded by the World Bank and managed by the Thai Ministry of Education (MOE). Study 3 was a case study of the development and implementation of a motorcycle helmet wearing program in Vietnam, which involved the transfer of Western knowledge, techniques and technology. The transfer agents were staff of Asia Injury (AI), a non-government organisation (NGO), and the program was funded initially by a charitable fund, with the intention of becoming self-funding through operation of a helmet factory.----- The case studies employed background research into existing information on economic, institutional, social and cultural factors relevant to the road safety issues (road use behaviour of school children in Thailand and motorcycle helmet purchase and wearing in Vietnam), and collected data through interviews with key informants, analysis of secondary sources and observations. This information was used to derive the road safety space for each road safety issue, to identify the road safety space recognised and addressed by the transfer agents (ARRB and AI), and to determine which factors they missed, or were aware of but took no action on. The focus of this analysis was on the processes used in transfer, not on the road safety outcomes of transfer, although these provided information on the processes as well. Available evaluation information was used to draw links between the omissions and the success of the transfer processes. It was noted that information on how the transferred measures operate should come from a road safety space analysis in the originating country, although this raised questions about selection of country and time (when the measure was first introduced, or in its maturity).----- The feasibility and utility of the road safety space model were discussed. It was clear that the model provided information on the cases which was missed by the transfer agents. The questions examined next were whether this information could have been obtained from an exercise conducted before the transfer had commenced, whether the required effort and cost justified the potential benefits, and whether the information on the road safety space could have been useful for the transfer agents. Comparisons between the road safety spaces for the two cases showed some areas of commonality, e.g. perceptions of police corruption, but also many differences. It was considered likely that some broad factors could be generic, and the possibility was mooted that less motorised countries share issues with police enforcement. This requires further research, however, and at this stage it is better to treat each road safety space as a unique combination of contextual factors influencing the road safety issue of interest.----- It is concluded that the road safety space model is feasible if used in such a way as to minimise the research involved, and useful, although the degree of utility needs to be further explored in a prospective study. The limitation introduced by restricting informants to those who could speak English are discussed. An approach using road safety space analysis is recommended, emphasising analysis of the country to which the road safety measure is being transferred, supplemented by analysis of the originating country road safety space. Gaps in knowledge are identified for further research and development, in particular the theoretical and practical understanding of road use behaviours and their modification in less motorised countries in Southeast Asia. Elaboration of the model is also recommended, to take into account the influence of the type of measure transferred, the role of the transfer agent, the area of road safety (education, engineering or enforcement), and the time dimension (the time which might be needed for a transfer to show its effects).----- The findings of this research are likely to be applicable to road safety transfer in other less motorised regions of the world, however prospective testing is needed. They may also be relevant to issues of transfer for areas other than road safety, in particular public health and traffic engineering, where similar economic, institutional, social and cultural issues come together.

International organisations such as the World Health Organisation highlight the road crash problem in less motorised (or developing, or low income) countries like those in Southeast Asia and recommend the adoption of Western road safety measures. However, there are many differences between highly motorised and less motorised countries which raise questions about how successfully Western road safety knowledge and expertise can be transferred.----- A review of the statistical information on road crashes shows a great deal of uncertainty about both the scale and likely trajectory of road fatalities globally, in less motorised countries and in Asia. It is generally agreed, however, that Asia accounts for around half of all road fatalities, and analysis of the limited available data shows both that Southeast Asia is not an atypical region of Asia in road safety terms, and that Thailand and Vietnam are not atypical of Southeast Asian countries.----- A literature review of recommended practice approaches to road safety transfer in Asia shows that there are many economic, institutional, social and cultural factors which potentially influence the success of transfer. The review also shows that there is no coherent, comprehensive approach which either conceptualises these factors and their relationship to transfer outcomes, or uses an analysis of these factors to plan or modify transfer. To address this gap, this thesis develops a 'road safety space' model as a tool for conceptualisation and analysis, based on a biological metaphor which views the transfer of road safety measures from one context to another as analogous to the transfer of a species into a new ecological space. The road safety space model explicitly considers economic, institutional, social and cultural factors (from specific to broad) which influence the particular road safety issue which a particular road safety transfer effort seeks to address. A central contention of this thesis is that the road safety space model is both a feasible and useful tool to improve the process of road safety transfer to less motorised countries. Road safety space analysis is seen to have a role in a broader process of selection of road safety measures for transfer, along with knowledge of how the measures are considered to operate.----- The research reported in this thesis is comprised of three studies. Study 1 reviewed evaluations of road safety transfer to Thailand and Vietnam. Studies 2 and 3 were case studies of road safety transfer to Thailand and Vietnam respectively.----- Study 1 was an analysis of existing evaluations of road safety transfer to Thailand and Vietnam. The aims were to analyse the evaluations for their consideration of contextual factors, as described in the road safety space model, and to discuss whether the road safety space model assisted in understanding the reasons for success or failure of transfer. However, very few such evaluations exist, and those that were found generally lacked information on whether contextual factors were considered. This indicated the need for a more detailed, in-depth qualitative investigation of particular cases of road safety transfer, in order to investigate the feasibility and utility of the road safety space model.----- Two case studies (Study 2 and Study 3) were conducted to test whether the road safety space approach was both feasible and useful as a means of improving road safety transfer efforts. Study 2 was a case study of the development and implementation in Thailand of a road safety education program for school children, which involved the transfer of Western research and techniques. The transfer agents (i.e. those who effected the road safety transfer) were Australian consultants working for the Australian Road Research Board (ARRB). The transfer was funded by the World Bank and managed by the Thai Ministry of Education (MOE). Study 3 was a case study of the development and implementation of a motorcycle helmet wearing program in Vietnam, which involved the transfer of Western knowledge, techniques and technology. The transfer agents were staff of Asia Injury (AI), a non-government organisation (NGO), and the program was funded initially by a charitable fund, with the intention of becoming self-funding through operation of a helmet factory.----- The case studies employed background research into existing information on economic, institutional, social and cultural factors relevant to the road safety issues (road use behaviour of school children in Thailand and motorcycle helmet purchase and wearing in Vietnam), and collected data through interviews with key informants, analysis of secondary sources and observations. This information was used to derive the road safety space for each road safety issue, to identify the road safety space recognised and addressed by the transfer agents (ARRB and AI), and to determine which factors they missed, or were aware of but took no action on. The focus of this analysis was on the processes used in transfer, not on the road safety outcomes of transfer, although these provided information on the processes as well. Available evaluation information was used to draw links between the omissions and the success of the transfer processes. It was noted that information on how the transferred measures operate should come from a road safety space analysis in the originating country, although this raised questions about selection of country and time (when the measure was first introduced, or in its maturity).----- The feasibility and utility of the road safety space model were discussed. It was clear that the model provided information on the cases which was missed by the transfer agents. The questions examined next were whether this information could have been obtained from an exercise conducted before the transfer had commenced, whether the required effort and cost justified the potential benefits, and whether the information on the road safety space could have been useful for the transfer agents. Comparisons between the road safety spaces for the two cases showed some areas of commonality, e.g. perceptions of police corruption, but also many differences. It was considered likely that some broad factors could be generic, and the possibility was mooted that less motorised countries share issues with police enforcement. This requires further research, however, and at this stage it is better to treat each road safety space as a unique combination of contextual factors influencing the road safety issue of interest.----- It is concluded that the road safety space model is feasible if used in such a way as to minimise the research involved, and useful, although the degree of utility needs to be further explored in a prospective study. The limitation introduced by restricting informants to those who could speak English are discussed. An approach using road safety space analysis is recommended, emphasising analysis of the country to which the road safety measure is being transferred, supplemented by analysis of the originating country road safety space. Gaps in knowledge are identified for further research and development, in particular the theoretical and practical understanding of road use behaviours and their modification in less motorised countries in Southeast Asia. Elaboration of the model is also recommended, to take into account the influence of the type of measure transferred, the role of the transfer agent, the area of road safety (education, engineering or enforcement), and the time dimension (the time which might be needed for a transfer to show its effects).----- The findings of this research are likely to be applicable to road safety transfer in other less motorised regions of the world, however prospective testing is needed. They may also be relevant to issues of transfer for areas other than road safety, in particular public health and traffic engineering, where similar economic, institutional, social and cultural issues come together.

The aim of this research is to utilize PhotoModeler, a closerange photogrammetry software package, in various traffic accident reconstruction applications. More specifically, three distinct studies were conducted: 1.) vehicle crush measurement, 2.) road curve measurement, and 3.) an evaluation of common traffic accident reconstruction measurement methodologies. The first study applied the photogrammetric process to controlled crash information generated by the National Highway Traffic Safety Administration (NHTSA). A statistical procedure known as bootstrapping was utilized to generate distributions from which the variability was examined. The “within” subject analysis showed that 44.8% of the variability is due to the technique itself and the “between” subjects analysis demonstrated that 55.2% of the variability is attributable to vehicle type—roughly half and half. Additionally, a 95% CI for the “within” analysis revealed that the mean difference (between this study and NHTSA) fell between -2.52 mph and +2.74 mph; the “between” analysis showed a mean difference between -3.26 and +2.41 mph. The second study focused on photogrammetry in road curve measurement. More particularly, this study applied photogrammetry to (simulated) road curves in lieu of traditional measurement methods, such as measuring tapes and measuring wheels. In this work, thirty (30) different radii of curvature of various known sizes were deliberately constructed. Then photogrammetry was used to measure each of the constructed curves. A comparison of the known “R’s” (control group) and photogrammetry’s value of “R” (treatment group) was then made. Matched Pairs or Paired Comparisons were then used to examine these two populations. The difference between the photogrammetry “R” and the known “R” range is between 0.001% and 0.874%. Additionally, we are 95% confident that the mean difference of the two techniques is between -0.33 and 0.51 feet. Since this interval contains zero, we can conclude that the two techniques do not differ.

碩士
中華大學
科技管理學系(所)
94
Domestic transportation in Taiwan is mainly depending on roads. A high-speed road network has been formed with national highways and 12 east-west express ways. In order to maximize the transportation effects of road network and build intellectual transportation system, the Ministry of Transportation and Communications R.O.C, according to National Freeway Traffic Control System has been planning and building a transportation management system to meet the demands for managing road network at various levels. National highway transportation management system, cooperating to local transportation characteristics, is a highly customized engineering project. Transportation data collected by various channels and equipment is transferred through communication subsystem to the computers in local traffic control centers/sub-centers for the purposes of announcement, pre-alarm, direction, accident handling, emergency treatment, etc. National freeway traffic control system is huge and complicated. It not only builds a new system but incorporates subsystems as well. Moreover, systems of other adjacent local roads and old/new management equipment are to be integrated, too. Thus, the uncertainty of risk from traffic control system project is increased due to various factors at different levels, including dependence, relevancy, partial information disclosure, etc. This research aims to analyze and identify risk factors of highway traffic control engineering from a project implementer’s point of view, starting from case studies which followed by questionnaires under professional assistances distributed to people serving traffic control industries. Both internal and external risk factors are incorporated into questionnaires. With factor analysis and SPSS, sample data collected is analyzed and identified to understand risk factors and relevancy of traffic control project. In the past, researches on traffic control system focused on system techniques instead of project management. This research is the first one to propose the specific structures and factors of risks of high-way traffic control for project managers to avoid expected risks and adjust relative plans and resources. Moreover, it can also serve to improve the performance of risk management and reduce loss from risks as a reference to project risk management mechanism and corresponding strategies.

Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 2008.
Source: Dissertation Abstracts International, Volume: 69-11, Section: B, page: 7009. Adviser: Rahim Benekohal. Includes bibliographical references (leaves 148-151) Available on microfilm from Pro Quest Information and Learning.

Conventional road safety models rely on historical crash data. Locations with high crash injury statistics are given primary interventions. However, crash data are subject to errors, under-reportings, inaccuracy, and requires years to get updated, as crash events are infrequent and partly random(Gettman, Pu, Sayed and Shelby, 2008), as well as road conditions might change. With the advances in connected vehicle technologies, vehicles can be used as mobile sensors that collects driver behavior information. And if found correlated with the crash data, the driver behavior indices can act as safety surrogate measures. This dissertation focuses first on presenting an algorithm for mapping a vehicle sensing big dataset to a digital road network, in a metropolitan city, using the accompanied GPS trajectories. This is a challenging task since the data collected from the on-board-diagnostic port of the vehicle is sampled at a low ping rate, adding to that the excess of GPS noise in urban canyons, which makes the map matching problem even harder. Next, a spatial correlation study is presented. It investigates the spatial relationship between the driver behavior indices (i.e. speed parameters, hard braking and hard acceleration) and crashes (crash frequencies and crash rates, normalized with traffic volume). Highways and non-highway roads are bucketed separately. The other focus of this dissertation is developing an injury-prediction network screening model, that provide safety ranking of road intersections. Novel explanatory variables are derived from the telematics data, such as intersection traffic maneuvers and traffic conflicts. The non-linearity between the explanatory variables as well as the spatial dependency between road intersection is also tested.

碩士
南開科技大學
福祉科技與服務管理所
103
The rates of the elderly population significantly increase due to national life extended with medical progress. By the end of 2013, the population in Taiwan is up to 23,373,517, the elderly people above 65 years old have been up to 2,695,406, having 11.53% of the total population. The following problems to social effects by the elder increase with population aging will increase day by day. According to National Police Agency, Ministry of the Interior statistics, there are 6,085 people died in Taiwan area in 2011 to 2013, the death number of the eider was 1,439,having 23.64% of the deaths. It shows that the rate of death of the elder is higher than other aged people when the car accidents happened. This research is based on the elder encountered 21 A1 class traffic accidents, using a theory "Service Experience Engineering Method, SEE" developed innovated application research institute of funding strategy in 2008.From the view of perpetrators and processing accident police, using the method of service experience observation and the interview carries out service to experience the context insight. To analyze the A1 class car accidents of the elders, get the five big behavior meeting whole model, including “meeting whole interactive model, and sequence model, and tool artifacts model, and culture model, and entity model” together and propose why the elder encountered A1 class car accidents was due to not wearing bright clothing, going through the road and not following the signs and the marks indicate, makes the elder have better traffic environment in the future. The results of this study are as follows: First, through the experience of SEE insight, it helps to understand seniors category A1 traffic style, behavior patterns, and the true cause and obstruction of the accident, engineering assessment for this study, the service experience, identifying seniors category A1 traffic accident cause and hidden service opportunities. Analyze accident factors of the elder to research measures about improving traffic security; By the results of the analysis about the elder encountered A1class car accidents, which are based on environment, walking is the most, what’s more is no-signals condition, the last is riding motorcycles in the slow lane; Based on the causes, not wearing bright clothing, not following the signs and the marks, and making turns are the most, and then is riding motorcycles not following the direction when making a right or a left turn. It obviously shows the elder encountered A1 class car accidents may be improved by the results of the analysis. That will reduce the elder encountered A1 class car accidents, promoting road safety for them. Keywords: Experience project, The elder, A1 class car accidents, Road safety.

abstract: This dissertation studies load balancing algorithms for many-server systems (with N servers) and focuses on the steady-state performance of load balancing algorithms in the heavy traffic regime. The framework of Stein’s method and (iterative) state-space collapse (SSC) are used to analyze three load balancing systems: 1) load balancing in the Sub-Halfin-Whitt regime with exponential service time; 2) load balancing in the Beyond-Halfin-Whitt regime with exponential service time; 3) load balancing in the Sub-Halfin-Whitt regime with Coxian-2 service time. When in the Sub-Halfin-Whitt regime, the sufficient conditions are established such that any load balancing algorithm that satisfies the conditions have both asymptotic zero waiting time and zero waiting probability. Furthermore, the number of servers with more than one jobs is o(1), in other words, the system collapses to a one-dimensional space. The result is proven using Stein’s method and state space collapse (SSC), which are powerful mathematical tools for steady-state analysis of load balancing algorithms. The second system is in even “heavier” traffic regime, and an iterative refined procedure is proposed to obtain the steady-state metrics. Again, asymptotic zero delay and waiting are established for a set of load balancing algorithms. Different from the first system, the system collapses to a two-dimensional state-space instead of one-dimensional state-space. The third system is more challenging because of “non-monotonicity” with Coxian-2 service time, and an iterative state space collapse is proposed to tackle the “non-monotonicity” challenge. For these three systems, a set of load balancing algorithms is established, respectively, under which the probability that an incoming job is routed to an idle server is one asymptotically at steady-state. The set of load balancing algorithms includes join-the-shortest-queue (JSQ), idle-one-first(I1F), join-the-idle-queue (JIQ), and power-of-d-choices (Pod) with a carefully-chosen d.
Dissertation/Thesis
Doctoral Dissertation Electrical Engineering 2019

The quality of Machine Translation (MT) can often be poor due to it appearing incoherent and lacking in fluency. These problems consist of word ordering, awkward use of words and grammar, and translating text too literally. However we should not consider translations such as these failures until we have done our best to enhance their quality, or more simply, their fluency. In the same way various processes can be applied to touch up a photograph, various processes can also be applied to touch up a translation. This research outlines the improvement of MT quality through the application of Fluency Enhancement (FE), which is a process we have created that reforms and evaluates text to enhance its fluency. We have tested our FE process on our own MT system which operates on what we call the SAM fundamentals, which are as follows: Simplicity - to be simple in design in order to be portable across different languages pairs, Adaptability - to compensate for the evolution of language, and Multiplicity - to determine a final set of translations from as many candidate translations as possible. Based on our research, the SAM fundamentals are the key to developing a successful MT system, and are what have piloted the success of our FE process.

Indiana University-Purdue University Indianapolis (IUPUI)
Pedestrian and vehicle interaction analysis in a naturalistic driving environment can provide useful information for designing vehicle-pedestrian crash warning/mitigation systems. Many researchers have used crash data to understand and study pedestrian behaviors and interactions between vehicles and pedestrian during crash. However, crash data may not provide detailed pedestrian-vehicle interaction information for us. In this thesis, we designed an automatic pedestrian tracking and status analysis method to process and study pedestrian and vehicle interactions. The proposed pedestrian tracking and status analysis method includes pedestrian detection, pedestrian tracking and pedestrian status analysis modules. The main contributions of this thesis are: we designed a new pedestrian tracking method by learning the pedestrian appearance and also their motion pattern. We designed a pedestrian status estimation method by using our tracking results and thus helped estimate the possibility of collision. Our preliminary experiment results using naturalistic driving data showed promising results.

The growth of interactive multimedia (IMM) applications is one of the major driving forces behind the swift evolution of next-generation wireless networks where the traffic is expected to be varying and widely diversified. The amalgamation of multimedia applications on high-speed wireless networks is somewhat a natural evolution. Wireless local area network (WLAN) was initially developed to carry non-real time data. Since this type of traffic is bursty in nature, the channel access schemes were based on contention. However real time traffic (e.g. voice, video and other IMM applications) are different from this traditional data traffic as they have stringent constraints on quality of service (QoS) metrics like delay, jitter and throughput. Employing contention free channel access schemes that are implemented on the point coordination function (PCF), as opposed to the numerous works on the contending access schemes, is the plausible and intuitive approach to accommodate these innate requirements. Published researches show that works have been done on improving the distributed coordination function (DCF) to handle IMM traffic. Since the WLAN traffic today is a mix of both, it is only natural to utilize both, DCF and PCF, in a balanced manner to leverage the inherent strengths of each of them. We saw a scope in this technique and develop a scheme that combines both contention and non-contention based phases to handle heterogeneous traffic in WLAN. Standard access scheme, like 802.11e, improves DCF functionality by trying to emulate the functions of PCF. Researchers have made a multitude of improvements on 802.11e to reduce the costs of implementing the scheme on WLAN. We explore improving the PCF, instead, as this is more stable and implementations would be less costly. The initial part of this research investigates the effectiveness of the point coordination function (PCF) for carrying interactive multimedia traffic in WLAN. The performance statistics of IMM traffic were gathered and analyzed. Our results showed that PCF-based setup for IMM traffic is most suitable for high load scenarios. We confirmed that there is a scope in improving IMM transmissions on WLAN by using the PCF. This is supported by published researches on PCF related schemes in carrying IMM traffic on WLAN. Further investigations, via simulations, revealed that partitioning the superframe (SF) duration according to the need of the IMM traffic has considerable impact on the QoS of the WLAN. A theoretical model has been developed to model the two phases, i.e., PCF and DCF, of WLAN medium access control (MAC). With this model an optimum value of the contention free period (CFP) was calculated to meet the QoS requirement of IMM traffic being transmitted. Treating IMM traffic as data traffic or equating both IMM and non-IMM together could compromise a fair treatment that should be given to these QoS sensitive traffic. A self-adaptive scheme, called MAC with Dynamic Superframe Selection (MDSS) scheme, generates an optimum SF configuration according to the QoS requirements of traversing IMM traffic. That particular scheme is shown to provide a more efficient transmission on WLAN. MDSS maximizes the utilization of CFP while providing fairness to contention period (CP). The performance of MDSS is compared to that of 802.11e, which is taken as the benchmark for comparison. Jitter and delay result for MDSS is relatively lower while throughput is higher. This confirms that MDSS is capable of making significant improvement to the standard access scheme.

Indiana University-Purdue University Indianapolis (IUPUI)
Yan, Jiaxiang. M.S.E.C.E., Purdue University, May 2013. Modeling, Monitoring and Optimization of Discrete Event Systems Using Petri Nets. Major Professor: Lingxi Li. In last decades, the research of discrete event systems (DESs) has attracts more and more attention because of the fast development of intelligent control strategies. Such control measures combine the conventional control strategies with discrete decision-making processes which simulate human decision-making processes. Due to the scale and complexity of common DESs, the dedicated models, monitoring methods and optimal control strategies for them are necessary. Among various DES models, Petri nets are famous for the advantage in dealing with asynchronous processes. They have been widely applied in intelligent transportation systems (ITS) and communication technology in recent years. With encoding of the Petri net state, we can also enable fault detection and identification capability in DESs and mitigate potential human errors. This thesis studies various problems in the context of DESs that can be modeled by Petri nets. In particular, we focus on systematic modeling, asynchronous monitoring and optimal control strategies design of Petri nets. This thesis starts by looking at the systematic modeling of ITS. A microscopic model of signalized intersection and its two-layer timed Petri net representation is proposed in this thesis, where the first layer is the representation of the intersection and the second layer is the representation of the traffic light system. Deterministic and stochastic transitions are both involved in such Petri net representation. The detailed operation process of such Petri net representation is stated. The improvement of such Petri net representation is also provided with comparison to previous models. Then we study the asynchronous monitoring of sensor networks. An event sequence reconstruction algorithm for a given sensor network based on asynchronous observations of its state changes is proposed in this thesis. We assume that the sensor network is modeled as a Petri net and the asynchronous observations are in the form of state (token) changes at different places in the Petri net. More specifically, the observed sequences of state changes are provided by local sensors and are asynchronous, i.e., they only contain partial information about the ordering of the state changes that occur. We propose an approach that is able to partition the given net into several subnets and reconstruct the event sequence for each subnet. Then we develop an algorithm that is able to reconstruct the event sequences for the entire net that are consistent with: 1) the asynchronous observations of state changes; 2) the event sequences of each subnet; and 3) the structure of the given Petri net. We discuss the algorithmic complexity. The final problem studied in this thesis is the optimal design method of Petri net controllers with fault-tolerant ability. In particular, we consider multiple faults detection and identification in Petri nets that have state machine structures (i.e., every transition in the net has only one input place and one output place). We develop the approximation algorithms to design the fault-tolerant Petri net controller which achieves the minimal number of connections with the original controller. A design example for an automated guided vehicle (AGV) system is also provided to illustrate our approaches.