Kinematics of stellar populations with RAVE data

We study the kinematics of the Galactic thin and thick disk populations using stars from the RAVE survey’s second data release together with distance estimates from Breddels et al. (2010). The velocity distribution exhibits the expected moving groups present in the solar neighborhood. We separate thick and thin disk stars by applying the X (stellar-population) criterion of Schuster et al. (1993), which takes into account both kinematic and metallicity information. For 1906 thin disk and 110 thick disk stars classified in this way, we find a vertical velocity dispersion, mean rotational velocity and mean orbital eccentricity of (σ_W, 〈V_Φ〉, 〈e〉)_thin = (18 ± 0.3 km s⁻¹, 223 ± 0.4 km s⁻¹, 0.07 ± 0.07) and (σ_W, 〈V_Φ〉, 〈e〉)_thick = (35 ± 2 km s⁻¹, 163 ± 3 km s⁻¹, 0.31 ± 0.16), respectively. From the radial Jeans equation, we derive a thick disk scale length in the range 1.5-2.2 kpc, whose greatest uncertainty lies in the adopted form of the underlying potential. The shape of the orbital eccentricity distribution indicates that the thick disk stars in our sample most likely formed in situ with minor gas-rich mergers and/or radial migration being the most likely cause for their orbits. We further obtain mean metal abundances of 〈[M/H]〉_thin = +0.03 ± 0.17, and 〈[M/H]〉_thick = −0.51 ± 0.23, in good agreement with previous estimates. We estimate a radial metallicity gradient in the thin disk of −0.07 dex kpc⁻¹, which is larger than predicted by chemical evolution models where the disk grows inside-out from infalling gas. It is, however, consistent with models where significant migration of stars shapes the chemical signature of the disk, implying that radial migration might play at least part of a role in the thick disk’s formation.     

基于改进邻域均值的全色影像水域提取

利用传统邻域均值法对全色影像水域进行提取时,所提取的水域边界精确度严重依赖于搜索窗口的大小。本文通过分析水域灰度特征以及提取边界不精确的原因,对方法进行针对性的改进:依据邻域各像素点与种子点的灰度差值分别对其赋予不同的灰度值,以处理后的邻域均值作为特征进行水域提取。实验结果表明:基于改进的邻域均值方法对遥感影像水域有较好的提取结果,提取精度较之改进前有明显改善。     

Making our neighborhoods,making our selves

In this paper, we explore a “grassroots” neighborhood revitalization effort engendered at the national scale without regard to local geographies of race and class. Specifically, we examine the Harambee Great Neighborhood Initiative, convened by the well-known nonprofit Habitat for Humanity together with Milwaukee’s Local Initiatives Support Corporation, in Milwaukee, Wisconsin. Drawing from participant observation, analysis of print and digital media, volunteer surveys, and interviews with area residents and local nonprofit representatives, we demonstrate the ways in which the six-year program of planning and neighborhood development was conceived and driven by an extra-local nonprofit with significant blind spots to local and organizational politics of race and without sufficient collaboration with the Harambee community. Our analysis points to the importance of race in nonprofit governance and community revitalization efforts. Moreover, we contribute to urban geographic scholarship on nonprofit governance by examining the dynamics of privilege, inclusion, and exclusion as they relate to practices of engagement and volunteerism in nonlocal “grassroots” projects.     

WAGE RATES,OCCUPATION STAFFING PATTERNS,AND THE LOCATION OF THE COMPUTER AND SEMICONDUCTOR INDUSTRIES: SOME TESTS OF A CITY-SIZE,INDUSTRIAL LOCATION SORTING MODEL

This research first develops a paradigm relating technology adoption, plant function, and location in different areas. It then examines empirically some of the paradigm's postulates dealing with occupation staffing patterns and wage rates in headquarters and production plants in different size cities and regions of the country using survey data. The research found that plants in large cities, headquarters plants, and plants in innovative regions paid higher wages than plants in small cities, production plants, and those in innovation-lagging regions. Headquarters plants and plants in large cities and innovative regions had a significantly larger number of scientists, engineers, and technicians on their staffs but few production workers. Production plants and those in small cities and towns and lagging regions had few professional workers but a significant number of production workers. For all types of plants an inverse relationship existed between plant size and city size. The postulated direct relationship between plant size and wage rates was not clearly evident in the survey data except for low skilled occupations. Neither was the relationship clearly evident in the U.S. Census data for the computer and semiconductor industries, as it was for total U.S. manufacturing.     

Beyond Gentrification: Mobilizing Communities and Claiming Space

During the 20th century, neighborhood change and the displacement of low-income residents from their homes has occurred in a variety of ways from the demolition of entire areas to more recent revitalization efforts emphasizing the building of community and new governance structures. In this paper, I argue two interrelated points. First, whereas economic displacement of low-income people from their homes and neighborhoods is one effect of neighborhood revitalization initiatives, there is a wider set of factors that constitutes the marginalization, displacement, and exclusion of certain population groups from effectively making claims on neighborhood space. Second, in an era of neoliberalization, whereby civil society is expected to play a larger role in neighborhood governance and the provision of social welfare, the formation and activities of neighborhood-based communities, and their relation to state and market forces, have become increasingly important factors to examine. In this article, I address these areas of inquiry through a case study of a neighborhood revitalization initiative in Chattanooga, Tennessee that has been under way since 1998.     

Sense of Place in Hamilton,Ontario: Empirical Results of a Neighborhood-Based Survey

Although the concept of sense of place has a long history in the social sciences, relatively few studies have attempted a quantitative analysis of sense of place at the neighborhood level. This study reports on the empirical findings of a sense of place survey developed and tested in two contrasting neighborhoods in Hamilton, Ontario, Canada: Southwest Mountain, an upper-middle-class suburban neighborhood and Northeast Industrial, a lower-income, working-class neighborhood located in the heart of the city's industrial district. The principal objective is to assess the relationship between sense of place and the socio-demographic characteristics of residents living in neighborhoods of very different socioeconomic status. This study also introduces a method for calculating a neighborhood sense of place score derived from a fully tested, validated survey instrument. It was found that sense of place was strongest in Southwest Mountain, and among seniors, long-term residents, unmarried people, and immigrants. In addition, residents with a lower level of education and those in the unpaid labor force had a stronger sense of place.     

Neighborhood size and spatial scale in raster-based slope calculations

Raster-based slope estimation is routine in GIS. Like many other terrain attributes, the slope at a location is determined from elevations of surrounding cells. This spatial extent – ‘neighborhood size’ – is often treated as the ‘spatial scale’ of the calculation. In fact, neighborhood size and spatial scale are two connected yet different concepts, but few studies have investigated the relationship between them. The distinction is important because neighborhood size is under user control whereas spatial scale is merely implicit in the computational method. This article attempts to clarify and provide a more precise meaning of the two terms by considering slope operators from the standpoint of the frequency (or wavenumber) domain. This article derives analytical expressions for the amplitude response functions of four popular slope estimators. These are used to characterize the individual methods and also to show that the neighborhood size and spatial scale of a slope calculation are not numerically the same. In fact, because there is no single spatial scale that can be unambiguously associated with a given neighborhood size, neighborhood size cannot be an adequate indicator of spatial scale. Furthermore, this article shows that different indices of ‘scale’ yield different impressions about the action of a slope estimator and its response to changing neighborhood size. Therefore, it is necessary to examine the amplitude response function when investigating the spatial scale. The article also provides guidance for GIS practitioners when selecting a slope estimation method.     

Regional divisions

A geographic perspective is utilized to test the hypothesis that the legal labels homicide and assault represent essentially similar behaviors. The data base describes some 1200 homicide and 32 000 serious assault victimizations in Dallas, TX, for 1981–85. Detailed comparisons across urban neighborhoods (differentiated by socioeconomic status) examine the demographic, temporal, locational, and weapons characteristics of both types of serious violence. The analysis indicates strong congruence between the offenses with respect to most attributes, implying that violence data should be classified differently for behavioral analyses.     

PATRIMONY OF THE SEA AND FISHERIES DEVELOPMENT IN LATIN AMERICA

Data from transportation studies are used to examine changes in accessibility to employment opportunities in the Milwaukee urban area from 1927 to 1963. Low-status areas of the city tended to experience the greatest decreases in employment accessibility compared with other parts of the urban area. Furthermore, increasing levels of employment accessibility were associated with greater amounts of new housing, whereas decreases in housing vacancies and population occured in areas with declining accessibility to employment.     

COMMENTS ON “SPATIAL VARIATION OF HILLSLOPE PROFILES IN THE CUMBERLAND PLATEAU,KENTUCKY” BY EDMUND B. WOOOS

Book Reviewed in this article:

Main Street: Northeastern Oregon: The Founding and Development of Small Towns. Barbara Ruth Bailey.

Food Politics: The Regional Conflict. David N. Balaam and Michael J. Carey, eds.

The International Economy and Industrial Development: Trade and Investment in the Third World. R. Ballance, J. Ansari and H. Singer.

Neighborhoods in Urban America. Ronald H. Bayor, ed.

The English Heartland. By Robert Beckinsale and Monica Beckinsale.

Regional Dimensions of Industrial Policy. Michael E. Bell and Paul S. Lande, eds.

Tension Areas of the World. D. Gordon Bennett, ed.

Latin America: an Introductory Survey. B. W. Blouet and O. M. Blouet, eds.

Integration and Division: Geographical Perspectives on the Northern Ireland Problem. Frederick W. Boal and J. Neville H. Douglas, eds.

Energy and Land Use. Robert W. Burchell and David Listokin, eds.

Slopes and Weathering. Michael Clarke and John Small.

Alaska's Rural Development. Peter G. Cornwall and Gerald McBeath, eds.

The Politics of Park Design: A History of Urban Parks in America. Galen Cranz.

World Congress on Land Policy, 1980, Proceedings. Matthew Cullen and Sharon Woolery, eds.

Oregon Divided: A Regional Geography. Samuel N. Dicken and Emily F. Dicken.

Urban Food Marketing and Third World Rural Development. T. Scarlett Epstein.

South Africa: Spatial Frameworks for Development. T. J. D. Fair.

Institutions and Geographical Patterns. Robin Flowerdew, ed.

Industrialization of U.S. Agriculture, An Interpretive Atlas. Howard F. Gregor.

Planning Theory: Prospects for the 1980s. Patsy Healy, Glen McDougall and Michael J. Thomas, eds.

Neighborhood Mobilization: Redevelopment and Response. Jeffrey R. Henig.

The American Urban System: A Geographical Perspective. R. J. Johnston.

Climate, History and the Modern World. Hubert H. Lamb.

Climate and History: Studies in Past Climates and Their Impact on Man. T. M. L. Wigley, M. J. Ingram and G. Farmer.

China: Railways and Agricultural Development, 1875–1935. Ernest P. Liang.

A Desirable Energy Future—A National Perspective. Robert S. Livingston, T. D. Anderson, T. M. Besmann, M. Olszewski, A. M. Perry, and C. D. West.

Topothesia: Essays Presented to T. S. Ó Máille. B. S. Mac Aodha, ed.

Transportation for the Poor: Research in Rural Mobility. Hal S. Maggied.

Land Uses in American Cities. Harold M. Mayer and Charles R. Haves.

Industrial Organisation and Location. Philip McDermott and Michael Taylor.

Human Adaptability: an Introduction to Ecological Anthropology. Emilio F. Moran.

Regional Analysis and the New International Division of Labor. Frank Moulaert and Patricia W. Salinas, eds.

The Nuclear War Atlas. Victoriaville, Quebec, Canada:

Urbanization and Environmental Quality. Isao Orishimo.

The Garden of Eden: The Botanic Garden and the Re-Creation of Paradise. John Prest.

Earthfire, The Eruption of Mount St. Helens. Charles Rosenfeld and Robert Cooke.

Contest for the South China Sea. Marwyn S. Samuels.

The Future of the Wetlands: Assessing Visual-Cultural Values. Richard C. Smardon, ed.

Tucson: the Life and Times of An American City. C. L. Sonnichsen.

The Geography of Multinationals. Michael Taylor and Nigel Thrift, eds.

Impact of Marine Pollution on Society. Virginia Tippie and Dana Kester.

Reviving the Industrial City: the Politics of Urban Renewal in Lyon and Birmingham. Jerry A. Webman.

Andean Reflections: Letters from Carl O. Sauer While on a South American Trip under a Grant from the Rockefeller Foundation, 1942. Robert C. West, ed.

Cartographic Drawing with Computers. P. Yoeli.