Analysing the design criteria of charging cordons

The idea of the efficient use of roads, which requires users to pay for the traffic congestion cost that they impose on an urban road network, is long established (Pigou, 1920; Walters, 1961). However, the gap between the constructive theory of road pricing and its real world application is significant due to the issue of public acceptance, technical feasibility, and the cost of implementation (Sharp, 1966; Verhoef et al, 1995; Stenman and Sterner, 1998; and Sumalee, 2000). Different charging regimes have been developed and studied including time or delay based charging, distance based charging, cordon or boundary based charging, and area based charging (Holland and Watson, 1978; May, 1992; Oldridge, 1990; Smith et al, 1994; and Ison, 1998). The cordon charging system is the core of the study in this paper where we are looking for criteria for the judgmental design of cordons. We use the term “judgmental cordon design” to describe the process to identify the best locations to levy the charges and specify the optimal charge levels based on professional judgment. This paper reviews the literature to identify design criteria in section 2, and then it describes a survey with six UK local authorities in section 3. Section 4 presents the results of the survey and finally section 5 discuss the results and draw the conclusions

Multi-concentric optimal charging cordon design

The performance of a road pricing scheme varies greatly by its actual design and implementation. The design of the scheme is also normally constrained by several practicality requirements. One of the practicality requirements which is tackled in this paper is the topology of the charging scheme. The cordon shape of the pricing scheme is preferred due to its user-friendliness (i.e. the scheme can be understood easily). This has been the design concept for several real world cases (e.g. the schemes in London, Singapore, and Norway). The paper develops a methodology for defining an optimal location of a multi-concentric charging cordons scheme using Genetic Algorithm (GA). The branch-tree structure is developed to represent a valid charging cordon scheme which can be coded using two strings of node numbers and number of descend nodes. This branch-tree structure for a single cordon is then extended to the case with multi-concentric charging cordons. GA is then used to evolve the design of a multi-concentric charging cordons scheme encapsulated in the twostring chromosome. The algorithm developed, called GA-AS, is then tested with the network of the Edinburgh city in UK. The results suggest substantial improvements of the benefit from the optimised charging cordon schemes as compared to the judgemental ones which illustrate the potential of this algorithm

Partition-based algorithm for estimating transportation network reliability with dependent link failures.

Evaluating the reliability of a transportation network often involves an intensive simulation exercise to randomly generate and evaluate different possible network states. This paper proposes an algorithm to approximate the network reliability which minimizes the use of such simulation procedure. The algorithm will dissect and classify the network states into reliable, unreliable, and un-determined partitions. By postulating the monotone property of the reliability function, each reliable and/or unreliable state can be used to determine a number of other reliable and/or unreliable states without evaluating all of them with an equilibrium assignment procedure. The paper also proposes the cause-based failure framework for representing dependent link degradation probabilities. The algorithm and framework proposed are tested with a medium size test network to illustrate the performance of the algorithm

A method to assess demand growth vulnerability of travel times on road network links

Many national governments around the world have turned their recent focus to monitoring the actual reliability of their road networks. In parallel there have been major research efforts aimed at developing modelling approaches for predicting the potential vulnerability of such networks, and in forecasting the future impact of any mitigating actions. In practice-whether monitoring the past or planning for the future-a confounding factor may arise, namely the potential for systematic growth in demand over a period of years. As this growth occurs the networks will operate in a regime closer to capacity, in which they are more sensitive to any variation in flow or capacity. Such growth will be partially an explanation for trends observed in historic data, and it will have an impact in forecasting too, where we can interpret this as implying that the networks are vulnerable to demand growth. This fact is not reflected in current vulnerability methods which focus almost exclusively on vulnerability to loss in capacity. In the paper, a simple, moment-based method is developed to separate out this effect of demand growth on the distribution of travel times on a network link, the aim being to develop a simple, tractable, analytic method for medium-term planning applications. Thus the impact of demand growth on the mean, variance and skewness in travel times may be isolated. For given critical changes in these summary measures, we are thus able to identify what (location-specific) level of demand growth would cause these critical values to be exceeded, and this level is referred to as Demand Growth Reliability Vulnerability (DGRV). Computing the DGRV index for each link of a network also allows the planner to identify the most vulnerable locations, in terms of their ability to accommodate growth in demand. Numerical examples are used to illustrate the principles and computation of the DGRV measure

Effective media-utility in learning

Thesis (Ph. D. in Education)--University of Tsukuba, (A), no. 2484, 2001.3.23Includes bibliographical reference

Prevalence of Class 1 Integrons and Antibiotic Resistance Patterns in Bacteria of Swine and Chicken in the US and Thailand

Studies were conducted to investigate the prevalence and potential for transfer of class 1 integrons and antimicrobial resistance in bacteria of broiler chickens and swine from the US and Thailand. Antibiograms were characterized and integron sequences were detected using standard methods. To determine if transfer of integrons occurred between bacterial species the location of the integrons (plasmid versus chromosome) was determined, and when integron-positive E. coli and Salmonella isolates possessed identical amplicon patterns, PCR products were sequenced to determine homology. Class 1 integrons were detected in 1,732 of 3,824 isolates from broiler chickens and 1,782 of 4,253 isolates from swine. Simultaneous presence of three conserved class 1 integron genes was found in 1,044 and 215 of isolates from chickens and swine, respectively. A high proportion of bacterial isolates from chickens demonstrated resistance to tetracycline, sulfamethoxazole, cephalothin, and ampicillin. A high proportion of isolates from swine demonstrated resistance to tetracycline, sulfamethoxazole, streptomycin, and ampicillin. Nine integron amplicons, with sizes ranging from 0.5 to 2.5 kb, were found, and we discovered a single swine farm on which similar integrons were observed in both E. coli and Salmonella. Sequence analysis revealed that a 1.0 kb amplicon found in both bacterial species contained an aadA1 gene cassette encoding aminoglycosides 3’-adenyltransferase, confering resistance to streptomycin and spectinomycin. A 2.0 kb amplicon was also found in both types of bacteria containing the aadA5 gene encoding aminoglycosides 3’-adenyltransferase, an additional reading frame with unknown function, orfD, as well as a dfrA17 gene encoding dihydrofolate reductase, conferring resistance to trimethoprim. Our results indicate that class 1 integrons are common in commensal and foodborne bacteria in broiler chickens and swine, and that some, but not all antibiotic resistances are associated with the presence of class 1 integrons. Identical integrons found in Salmonella and E. coli from a single farm likely indicate transfer between these two organisms occurs via exchange of plasmids. This work provides additional knowledge regarding the complex nature of antibiotic resistance gene acquisition, reservoirs, and transfer that should aid in development of courses of action and strategies for control of these potential foodborne and zoonotic hazards

A graph-based algorithm for interpersonal ties clustering in signed networks

Social ties are formed as a result of interactions and individual preferences of the people in a social network. There are two opposite types which are interpreted as friendship vs. enmity or trust vs. distrust between people. The aforementioned social network structure can be represented by a signed graph, where people are the graph’s vertices and their interactions are graph’s edges. The edges can be positive and negative signs. To determine trustworthiness, this paper considers the problem of a signed graph partitioning with minimizing the sum of the negative edge\u27s weight and balanced size of its clusters. An efficient algorithm to solve such a problem is proposed. The experimental results show that the proposed algorithm outperforms in terms of the execution times and the accuracy within the given bounds

The association of primary open-angle glaucoma / normal tension glaucoma and obstructive sleep apnea in Thai patients

 Backgrouds: The association of glaucoma and OSA has been published in many reports. Previous study by Mojon et al demonstrated that repeated hypoxia may affect the development of ganglion cell loss. However, it remains unclear whether glaucoma is association with OSA. Thus, objective of this study is to determine the association of primary open-angle glaucoma / normal tension glaucoma and obstructive sleep apnea in Thai patients.Materials and Methods: Eighty-six patients consecutively admitted for polysomnographic evaluation of suspected obstructive sleep apnea were performed complete ophthalmologic examination. The association between glaucoma and OSA was determined by the Chi-square test and Pearson correlation. P-value < 0.05 were considered statistically significant.Results: Forty-four of the eighty-six patients (51.16 %) who had an AHI higher than 10 and were diagnosed with OSA. Eighteen of them had mild OSA, twelve patients had moderated OSA and fourteen patients had severe OSA. The prevalence of glaucoma in normal group was 7.14 %(3/42). The prevalence of glaucoma in patients with OSA was 13.64%(6/44). There was no statistically significant correlation between presence of glaucoma and OSA. (Chi-square = 9.67; df  = 1; p-value = 0.325)Conclusions: This study indicates that there is no statistically significant association between the presence of glaucoma and OSA in Thai patients. Therefore, the screening for glaucoma in patients with OSA might not be necessary unless further data of the relationship is present

A Semilinear Wave Equation with Nonmonotone Nonlinearity

We prove that a semilinear wave equation in which the range of the derivative of the nonlinearity includes an eigenvalue of infinite multiplicity has a solution. The solution is obtained through an iteration scheme which provides a priori estimates