Distributed optimization in transportation and logistics networks

Many important problems in communication networks, transportation networks, and logistics networks are solved by the minimization of cost functions. In general, these can be complex optimization problems involving many variables. However, physicists noted that in a network, a node variable (such as the amount of resources of the nodes) is connected to a set of link variables (such as the flow connecting the node), and similarly each link variable is connected to a number of (usually two) node variables. This enables one to break the problem into local components, often arriving at distributive algorithms to solve the problems. Compared with centralized algorithms, distributed algorithms have the advantages of lower computational complexity, and lower communication overhead. Since they have a faster response to local changes of the environment, they are especially useful for networks with evolving conditions. This review will cover message-passing algorithms in applications such as resource allocation, transportation networks, facility location, traffic routing, and stability of power grids.

Towards sustainable urban futures : evaluating urban sustainability performance of the Gold coast, Australia

Creating sustainable urban environments is one of the challenging issues that need a clear vision and implementation strategies involving changes in governmental values and decision making process for local governments. Particularly, internalisation of environmental externalities of daily urban activities (e.g. manufacturing, transportation and so on) has immense importance for which local policies are formulated to provide better living conditions for the people inhabiting urban areas. Even if environmental problems are defined succinctly by various stakeholders, complicated nature of sustainability issues demand a structured evaluation strategy and well-defined sustainability parameters for efficient and effective policy making. Following this reasoning, this study involves assessment of sustainability performance of urban settings mainly focusing on environmental problems caused by rapid urban expansion and transformation. By taking into account land-use and transportation interaction, it tries to reveal how future urban developments would alter daily urban travel behaviour of people and affect the urban and natural environments. The paper introduces a grid-based indexing method developed for this research and trailed as a GIS-based decision support tool to analyse and model selected spatial and aspatial indicators of sustainability in the Gold Coast. This process reveals parameters of site specific relationship among selected indicators that are used to evaluate index-based performance characteristics of the area. The evaluation is made through an embedded decision support module by assigning relative weights to indicators. Resolution of selected grid-based unit of analysis provides insights about service level of projected urban development proposals at a disaggregate level, such as accessibility to transportation and urban services, and pollution. The paper concludes by discussing the findings including the capacity of the decision support system to assist decision-makers in determining problematic areas and developing intervention policies for sustainable outcomes of future developments.

El sistema de transporte de carga en la Ciudad de México Factores a considerar en el análisis del transporte de carga y la movilidad de mercancías

El artículo presenta un análisis del sistema de transporte de carga en la Ciudad de México desde el punto de vista sistémico, considerando las variables económicas, políticas, técnicas, sociales que permitan comprender la problemática que actualmente enfrenta esta ciudad en la movilidad de mercancías. Es una reflexión de carácter multidisciplinario basada en el método cualitativo para explicar y comprender la situación actual del transporte de carga en México dentro del contexto de la globalización económica, para identificar así la naturaleza profunda de la estructura dinámica del transporte de carga en la Ciudad y la nueva forma de conceptualizar al transporte de mercancías. Se estudia el comportamiento de los flujos e infraestructura de las redes viales, las características urbanas, los instrumentos jurídicos en las políticas del transporte, la problemática del transporte de carga, así como la movilidad y los diferentes problemas que enfrenta el sector en relación con la ciudad. El objetivo principal de presente artículo es enunciar las razones por las que no existe un sistema de transporte articulado y se privilegia el uso del autotransporte de carga. Finalmente, de acuerdo a las diversas variables analizadas, se establece en las conclusiones que el análisis y la planificación de los transportes debe ser multi e interdisciplinario por naturaleza, con una visión integral para establecer un equilibrio entre los modos de transporte. 

Development of a conceptual model for mass gatherings

In making the arrangements for the visit of Pope John Paul II to San Antonio, Texas, in September, 1987, it was discovered that no comprehensive documents or guidelines are available in the public sector for planning such an event. It was not clear which, if any, laws applied. The literature describes rock concerts, papal masses, and civil disorders. These events are held in stadia, and in the open. There was little agreement on what services, if any, were needed to protect the public's health and the environment; or if needed, how services should be provided, or by whom.^ A literature review and bibliography are given to provide greater understanding of the variety of mass gatherings and the many factors that impinge on temporary groups while away from their homes. Descriptions of past mass gatherings in terms of personnel ratios are provided. This study develops a conceptual model which delineates some of the known parameters necessary for successfully conducting a mass gathering. A study of one such site is given.^ Provisions for public wellness and freedom from disease at a mass gathering include adequate water (fluids), food, sanitary facilities, security, transportation, and medical services. The determination of adequacy of these provisions is discussed. Methods of determining the use of provided facilities are given. ^

Private higher education policy in Ohio, 1980--2006: A case study demonstrating the usefulness of Zumeta's public policy posture model

This study describes the case of private higher education in Ohio between 1980 and 2006 using Zumeta's (1996) model of state policy and private higher education. More specifically, this study used case study methodology and multiple sources to demonstrate the usefulness of Zumeta's model and illustrate its limitations. Ohio served as the subject state and data for 67 private, 4-year, degree-granting, Higher Learning Commission-accredited institutions were collected. Data sources for this study included the National Center for Education Statistics Integrated Postsecondary Data System as well as database information and documents from various state agencies in Ohio, including the Ohio Board of Regents. ^ The findings of this study indicated that the general state context for higher education in Ohio during the study time period was shaped by deteriorating economic factors, stagnating population growth coupled with a rapidly aging society, fluctuating state income and increasing expenditures in areas such as corrections, transportation and social services. However, private higher education experienced consistent enrollment growth, an increase in the number of institutions, widening involvement in state-wide planning for higher education, and greater fiscal support from the state in a variety of forms such as the Ohio Choice Grant. This study also demonstrated that private higher education in Ohio benefited because of its inclusion in state-wide planning and the state's decision to grant state aid directly to students. ^ Taken together, this study supported Zumeta's (1996) classification of Ohio as having a hybrid market-competitive/central-planning policy posture toward private higher education. Furthermore, this study demonstrated that Zumeta's model is a useful tool for both policy makers and researchers for understanding a state's relationship to its private higher education sector. However, this study also demonstrated that Zumeta's model is less useful when applied over an extended time period. Additionally, this study identifies a further limitation of Zumeta's model resulting from his failure to define "state mandate" and the "level of state mandates" that allows for inconsistent analysis of this component. ^

Responsive multimodal transportation management strategies and IVHS. Final report.

Federal Highway Administration, Office of Safety and Traffic Operations Research and Development, McLean, Va.

Urban transportation policies and activities - a report to the Congress of the U.S. Final report.

Mode of access: Internet.

Selected views and issues related to regulatory reform in the transportation industry.

Mode of access: Internet.

Trends in federal domestic transportation programs, revenues and expenditures by state: fiscal years 1957-1975. Final report.

Mode of access: Internet.

Transportation statistical data and information. Final report.

Transportation Department, Office of Transportation Systems Analysis and Information, Washington, D.C.

Charges for private use of federally-provided transportation services and facilities;

Mode of access: Internet.

Future cenario planning in Brazilian logistics and transportation sector

Nas últimas décadas o setor de logística passou por grandes transformações pelo mundo. Assim, a eficiência do sistema logístico é importante para o crescimento econômico, a diversificação, redução dos custos operacionais e da pobreza. Segundo o Banco Mundial, o Brasil tornou-se uma das maiores economias do mundo, mas os custos logísticos elevados colocam em risco esse crescimento. Estes custos são em grande parte o resultado de diferenças em infraestrutura de cada região, juntamente com os encargos do setor rodoviário, que corresponde por 60% do total do transporte de carga do país. Entretanto, a logística brasileira está às portas de uma nova revolução, em práticas de negócios e eficiência, e também na qualidade e disponibilidade da infraestrutura de transportes e comunicações, e novos projetos e práticas para superar a situação. O objetivo deste estudo não é analisar o presente e as atuais tendências de logística do Brasil e do setor de transporte, mas sim modelar possíveis cenários futuros para os próximos anos. Em outras palavras, este trabalho mostra diferentes possibilidades de como o setor de logística e transporte poderá ser no futuro. Para isso, este trabalho irá utilizar a metodologia de cenários prospectivos e entrevistas com especialistas relacionados da área.

Training in the inland freight transportation sector in Latin America

This issue of the FAL Bulletin covers training in the inland freight transportation and logistical operations sector in Latin America and its role in productivity and competitiveness.

Prevalence and risk factors of asthma and work -related asthma among U.S. adults: Data from the Third National Health and Nutrition Examination Survey, 1988--1994

This cross-sectional analysis of the data from the Third National Health and Nutrition Examination Survey was conducted to determine the prevalence and determinants of asthma and wheezing among US adults, and to identify the occupations and industries at high risk of developing work-related asthma and work-related wheezing. Separate logistic models were developed for physician-diagnosed asthma (MD asthma), wheezing in the previous 12 months (wheezing), work-related asthma and work-related wheezing. Major risk factors including demographic, socioeconomic, indoor air quality, allergy, and other characteristics were analyzed. The prevalence of lifetime MD asthma was 7.7% and the prevalence of wheezing was 17.2%. Mexican-Americans exhibited the lowest prevalence of MD asthma (4.8%; 95% confidence interval (CI): 4.2, 5.4) when compared to other race-ethnic groups. The prevalence of MD asthma or wheezing did not vary by gender. Multiple logistic regression analysis showed that Mexican-Americans were less likely to develop MD asthma (adjusted odds ratio (ORa) = 0.64, 95%CI: 0.45, 0.90) and wheezing (ORa = 0.55, 95%CI: 0.44, 0.69) when compared to non-Hispanic whites. Low education level, current and past smoking status, pet ownership, lifetime diagnosis of physician-diagnosed hay fever and obesity were all significantly associated with MD asthma and wheezing. No significant effect of indoor air pollutants on asthma and wheezing was observed in this study. The prevalence of work-related asthma was 3.70% (95%CI: 2.88, 4.52) and the prevalence of work-related wheezing was 11.46% (95%CI: 9.87, 13.05). The major occupations identified at risk of developing work-related asthma and wheezing were cleaners; farm and agriculture related occupations; entertainment related occupations; protective service occupations; construction; mechanics and repairers; textile; fabricators and assemblers; other transportation and material moving occupations; freight, stock and material movers; motor vehicle operators; and equipment cleaners. The population attributable risk for work-related asthma and wheeze were 26% and 27% respectively. The major industries identified at risk of work-related asthma and wheeze include entertainment related industry; agriculture, forestry and fishing; construction; electrical machinery; repair services; and lodging places. The population attributable risk for work-related asthma was 36.5% and work-related wheezing was 28.5% for industries. Asthma remains an important public health issue in the US and in the other regions of the world. ^