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Big Cities (big + city)
Selected AbstractsBIG CITY, BIG TURNOUT?JOURNAL OF URBAN AFFAIRS, Issue 1 2007ELECTORAL PARTICIPATION IN AMERICAN CITIES ABSTRACT:,This article seeks to describe and explain variation in voter turnout in American big city municipal elections using data from 332 mayoral elections in 38 large U.S. cities over 25 years. In my cross-sectional time-series analysis of turnout in mayoral elections, I find that city-level demographic factors are only weakly correlated with turnout. By contrast, institutional and campaign factors explain much of the variation. The effect of Progressive era reforms on depressing turnout is greatest in the most competitive elections. I conclude by discussing the implication of the overall downward trend in turnout and changes cities can make to increase participation. [source] Seismic microzonation of the greater Bangkok area using microtremor observationsEARTHQUAKE ENGINEERING AND STRUCTURAL DYNAMICS, Issue 2 2004Rabin Tuladhar Abstract Bangkok, the capital city of Thailand, is located at a remote distance from seismic sources. However, it has a substantial risk from these distant earthquakes due to the ability of the underlying soft clay to amplify ground motions. It is therefore imperative to conduct a detailed seismic hazard assessment of the area. Seismic microzonation of big cities, like Bangkok, provides a basis for site-specific hazard analysis, which can assist in systematic earthquake mitigation programs. In this study, a seismic microzonation map for the greater Bangkok area is constructed using microtremor observations. Microtremor observations were carried out at more than 150 sites in the greater Bangkok area. The predominant periods of the ground were determined from the horizontal-to-vertical (H/V) spectral ratio technique. A microzonation map was then developed for the greater Bangkok area based on the observations. Moreover, the transfer functions were calculated for the soil profile at eight sites, using the computer program SHAKE91, to validate the results from the microtremor analysis. The areas near the Gulf of Thailand, underlaid by a thick soft clay layer, were found to have long natural periods ranging from 0.8s to 1.2s. However, the areas outside the lower central plain have shorter predominant periods of less than 0.4s. The study shows that there is a great possibility of long-period ground vibration in Bangkok, especially in the areas near the Gulf of Thailand. This may have severe effects on long-period structures, such as high-rise buildings and long-span bridges. Copyright © 2003 John Wiley & Sons, Ltd. [source] Why Do the Young and Educated in LDCs Concentrate in Large Cities?ECONOMICA, Issue 285 2005Evidence from Migration Data Do the young and educated in LDCs have a greater preference to locate in big cities? If so, this may help to explain how cities spatially concentrate the educated and young, and why the rising share of these workers in many LDCs may contribute to city growth. This paper explores migration flows into and out of Egypt's three largest cities. We study whether the higher shares of such workers in cities arise because these workers perceive relatively greater benefits from living in cities, given relative urban/rural wage rates, or because the relative demand for these workers rises with city size. [source] Potential of biomass-fired combined heat and power plants considering the spatial distribution of biomass supply and heat demandINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 11 2010Johannes Schmidt Abstract Combined heat and power (CHP) plants fired by forest wood can significantly contribute to attaining the target of increasing the share of renewable energy production. However, the spatial distribution of biomass supply and of heat demand limits the potentials of CHP production. This article assesses CHP potentials using a mixed integer programming model that optimizes locations of bioenergy plants. Investment costs of district heating infrastructure are modeled as a function of heat demand densities, which can differ substantially. Gasification of biomass in a combined cycle process is assumed as production technology. Some model parameters have a broad range according to a literature review. Monte-Carlo simulations have therefore been performed to account for model parameter uncertainty in our analysis. The model is applied to assess CHP potentials in Austria. Optimal locations of plants are clustered around big cities in the east of the country. At current power prices, biomass-based CHP production allows producing around 3% of the total energy demand in Austria. Yet, the heat utilization decreases when CHP production increases due to limited heat demand that is suitable for district heating. Production potentials are most sensitive to biomass costs and power prices. Copyright © 2009 John Wiley & Sons, Ltd. [source] Pinpointing users with location estimation techniques and Wi-Fi hotspot technologyINTERNATIONAL JOURNAL OF NETWORK MANAGEMENT, Issue 5 2008Kevin Curran Location awareness is becoming an important capability for mobile computing; however, it has not been possible until now to provide cheap pervasive positioning systems. Wide area coverage is most famously achieved by using global positioning systems (GPS). A constellation of low-orbit satellites cover the earth's surface. Unfortunately GPS does not work indoors and has limited success in big cities because of the ,urban canyon' effect. PlaceLab is a research project that attempts to solve the ubiquity issues surrounding 802.11-based location estimation. PlaceLab, like RADAR, uses a device's 802.11 interface; however, it does not require the area to be pre-calibrated. It predicts location via the known positions of the access points detected by the device. Commonly used systems have a number of drawbacks, including cost, accuracy and the ability to work indoors. PlaceLab is a piece of open source software developed by Intel Research that can pinpoint a user within a Wi-Fi network. We set out here to investigate whether PlaceLab can be used as a means of establishing a user's position. This type of investigation could, if successful, pave the way for the development of other location-based applications. This report documents the efforts to answer the above question. PlaceLab was found to work, but only in ideal locations where factors such as the number of floors and the lack of available APs did not affect its use. It was concluded that these factors prevent the system from being effective as a means of establishing a user's position in most locations on campus. Copyright © 2008 John Wiley & Sons, Ltd. [source] Prevalence of obesity and associated socioeconomic factors among Tunisian women from different living environmentsOBESITY REVIEWS, Issue 2 2009L. Beltaïfa Summary Adult Tunisian women aged 20,59 (national random sample, n = 1849), were assessed with respect to environmental and socioeconomic factors associated with obesity (body mass index ,30 kg m,2) and abdominal obesity (waist circumference ,88 cm). At the national level, prevalence of obesity and abdominal obesity were, respectively, 22.6% and 29.2%, but varied markedly (both P < 0.0001) among living environments classified as big cities (30.2% and 36.6%), other cities (25.9% and 32.4%), rural clustered (19.4% and 24.8%) and rural dispersed (9.5% and 16.5%). Adjusted prevalences of both types of obesity increased with age, parity and economic level of the household, while educationally, the risk was greatest in women with intermediate schooling. Differences between the four environments were accounted for by socioeconomic factors, mostly household wealth, except for most rural environment; socio-cultural factors were possibly influential. Observed differences between rural areas confirmed that finer measures of urbanization are necessary for the drivers of obesity prevalence at the national level. Obesity was still more prevalent in wealthy than in poor women, but given the high prevalence in all the environments, actions are needed at the national level before highly prevalent obesity extends into those of lower socioeconomic status and thereby increases health inequities. [source] PERCEPTION OF IRRADIATED FOODS AMONG STUDENTS (SECONDARY, UNIVERSITY [FOOD SCIENCE AND NONFOOD SCIENCE]) AND ADULTS IN ARGENTINAJOURNAL OF FOOD PROCESSING AND PRESERVATION, Issue 3 2008ALEJANDRA FLORES ABSTRACT A survey on beliefs and purchase intent of irradiated foods was conducted among 300 Argentine students, covering secondary/high school, food science and nonfood science university, and 100 nonstudent adults. Other factors considered were the type of information provided (introductory, process description and benefits) and the city of residence (small agricultural city and big city). The most important benefits were considered to be microorganism reduction and improved sanitation. On the other hand, insecurity and doubts were the main reasons why respondents would not buy these foods. Only 14% said they would definitely buy irradiated foods. Considering their doubts and insecurities, it is probable that if these respondents see a food labeled as "irradiated," they would not choose to buy it. Within developing countries such as Argentina, the promotion of this technology by government agencies would be very costly, and at present, these costs would not seem to be justified. PRACTICAL APPLICATIONS The negative perceptions of consumers would hinder the successful implementation of food irradiation. The doubts or insecurities that consumers of developing countries have are similar to those that consumers of developed countries have. Most respondents answered that irradiated foods should be labeled as such. If food irradiation was to be pursued further, the place to start would be in food science curricula as this is the basis of future professionals in charge of researching its use and/or implementing the process. [source] | ||||||||||