bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling Residential and Business Telecommunication Flows: A Regional Point‐to‐Point Approach
Authors: Guldmann Jean‐Michel
Published: September 2010

Regional telecommunication flows, measured in terms of numbers of messages and conversation minutes, are analyzed with a systematic random sample of toll calls characterized by their timing, duration, cost, and origin‐destination (O‐D) locations. Point‐to‐point models are econometrically estimated, with such independent variables as destination market size, O‐D distance, and average and time‐of‐day (TOD) prices, for the residential and business sectors separately. The results indicate that (1) the demands for calls and conversation minutes are price‐inelastic and slightly elastic, respectively, (2) business demand is relatively more price‐elastic than residential demand, (3) distance is a strong determinant of telephone demand, and (4) most TOD demand substitutions resulting from TOD price changes would take place between the daily and evening rate periods. Several areas for further research are outlined.
The Analysis of Spatial Association by Use of Distance Statistics
Authors: Getis Arthur , Ord J. K.
Published: September 2010

Introduced in this paper is a family of statistics,G, that can be used as a measure of spatial association in a number of circumstances. The basic statistic is derived, its properties are identified, and its advantages explained. Several of theGstatistics make it possible to evaluate the spatial association of a variable within a specified distance of a single point. A comparison is made between a generalGstatistic and Moran'sIfor similar hypothetical and empirical conditions. The empirical work includes studies of sudden infant death syndrome by county in North Carolina and dwelling unit prices in metropolitan San Diego by zip‐code districts. Results indicate thatGstatistics should be used in conjunction withIin order to identify characteristics of patterns not revealed by theIstatistic alone and, specifically, theGiandGi* statistics enable us to detect local “pockets” of dependence that may not show up when using global statistics.
Simulating Sources of Uncertainty in Policy Forecasting with a Large‐Scale Regional Econometric Model
Authors: Giarratani Frank , Houston David B.
Published: September 2010

Long‐term forecasts may be helpful in establishing the general framework for a region's policy agenda, and a well‐structured economic model offers an opportunity to identify major policy instruments affecting a region's long‐term growth. Nevertheless, the uncertainty of long‐term forecasts should serve to caution policymakers in interpreting and acting upon such information. To offer perspective on this aspect of forecasts, simulations of the Pittsburgh economy are performed to the year 1995 using a large‐scale regional econometric model. The forecasts are based on alternative assumptions concerning the performance of the national economy and the objective conditions characterizing key industries in the region. In this way, the model is used to identify and quantify several major sources of uncertainty in long‐term regional forecasts.
Diversity in Peasant Economic Behavior: Transmigrant Households in South Sumatra, Indonesia
Authors: Leinbach Thomas R. , Bowen John T.
Published: September 2010

An important facet of peasant economics is the diversification of household labor among farm and off‐farm activities. Using a sample of South Sumatran transmigrant households the diversification of household labor among various remunerative activities was analyzed. Employment diversity was related to three sets of theoretically based factors: demographic, human capital, and agricultural. Results from a discriminant analysis model reveal that the demographic set of variables is most powerful in distinguishing households with different levels of employment diversity. The ratio of consumers to workers in a household is particularly important. However, measures of entrepreneurship and on‐farm agricultural intensity are also useful in explaining diversity behavior. Throughout our analysis we find evidence that the role of the spouse as an income producer is especially critical in the household employment diversification process.
The Dynamics of Regional Invention and Innovation: Innovative Capacity and Regional Change in the Twentieth Century
Authors: Suarez‐Villa Luis
Published: September 2010

The twentieth century dynamics of United States regional invention trends are explored in this study. Historically, regions that become major loci of invention have always gained much influence, through innovation diffusion, their human capital infrastructures, and their national economic and political projection. The United States has experienced a remarkable inversion of regional roles on invention since the middle of the twentieth century, where the predominant position of heartland regions (the Northeast and the Midwest) is being overturned. This analysis develops a macro‐level measure of inventive output, innovative capacity, to evaluate changes in regional inventive performance and the potential for innovation. The analysis of patent age cycles provides insights on the temporal structure of the national and regional innovative capacity, and on the dynamics of crisis periods for U.S. scientific and technological invention. A consideration of regional income trends over the twentieth century and of innovative capacity performance shows the potential importance of endogenously generated inventions for regional development.
A Programming Approach to Minimizing and Maximizing Spatial Autocorrelation Statistics
Authors: Boots Barry , Dufournaud Christian
Published: September 2010

A programming approach is presented for identifying the form of the weights matrix W which either minimizes or maximizes the value of Moran's spatial autocorrelation statistic for a specified vector of data values. Both nonlinear and linear programming solutions are presented. The former are necessary when the sum of the links in W is unspecified while the latter can be used if this sum is fixed. The approach is illustrated using data examined in previous studies for two variables measured for the counties of Eire. While programming solutions involving different sets of constraints are derived, all yield solutions in which the number of nonzero elements in W is considerably smaller than that in W defined using the contiguity relationships between the counties. In graph theory terms, all of the Ws derived define multicomponent graphs. Other characteristics of the derived Ws are also presented.
Interpreting Spatial Economic Structure and Spatial Multipliers: Three Perspectives
Authors: Sonis Michael , Hewings Geoffrey J. D. , Lee Jong Kun
Published: September 2010

The measurement and interpretation of spatial economic structure have presented many problems for analysts. The notion of a spatial multiplier has received even less formal attention; part of the motivation for this paper is the examination of the degree to which sectoral decomposition analysis might prove useful in illuminating the paths of interaction across space that are associated with changes in exogenous activity levels. In this paper, we present three perspectives that examine spatial structure in the context of an aggregated interregional social accounting matrix for Bangladesh. These perspectives examine structure at the micro‐, meso‐, and macrolevels and are interpreted with the assistance of several alternative methods, including structural path analysis, the field of influence, the superposition principle, multiregional feedback loop analysis, and the Matrioshka Principle; the results are interpreted analytically and cartographically. Some attention is also devoted to the formulation of a general approach to spatial multipliers. It is shown that the structure of flows and the structure of influence reveal patterns that, taken together, provide important insights into an understanding of structure and may prove to form the basis for the eventual formal presentation of the spatial multiplier.
Application of Artificial Neural Networks in Climatology: A Case Study of Sunspot Prediction and Solar Climate Trends
Authors: Gopal Sucharita , Scuderi Louis
Published: September 2010

Global temperature trends on time scales of years to centuries have recently been shown to be related to volcanic aerosols, carbon dioxide levels, and solar activity. The most visible and well‐studied indicators of solar variability are dark areas or “sunspots” on the surface of the Sun, with sunspot numbers directly related to the level of solar activity. Prediction of sunspot numbers in advance of the actual event has proven problematic with most methods failing due to nonlinearities in solar activity. An approach using the generation of a feedforward neural network may resolve some of the difficulties inherent in currently utilized statistical and precursor approaches since feedforward networks offer a useful and practical method of approximating nonlinear relations and their derivatives without knowing the actual underlying nonlinear function. In this paper, we show some preliminary findings in using feedforward neural networks for the prediction of peak sunspot cycle amplitude and discuss the climatic implications of the findings.
Data Generation Processes for Spatial Series: The Example of Ephemeral Channel Form
Authors: Alexander C. O. , Rendell H. M.
Published: September 2010

Recently developed techniques for time series analysis are applied to channel width and slope series collected in small ephemeral channels in Southern Italy. Tests for the difference between trend and difference stationarity, although developed in the field of econometrics, are found to be more suitable for data generation processes in geomorphology, where physical causes of deterministic trends are evident. These tests are important because the modeling of causal flows and development of dynamic predictive models depends on the type of data generation process that is identified. The ephemeral channel data exhibit trend stationarity and the results of spectral analysis and vector autoregression analysis of detrended channel width and slope data are described.
Local Spatial Autocorrelation Statistics: Distributional Issues and an Application
Authors: Ord J. K. , Getis Arthur
Published: September 2010

The statisticsGi(d)andGi*(d),introduced in Getis and Ord (1992) for the study of local pattern in spatial data, are extended and their properties further explored. In particular, nonbinary weights are allowed and the statistics are related to Moran's autocorrelation statistic, I. The correlations between nearby values of the statistics are derived and verified by simulation. A Bonferroni criterion is used to approximate significance levels when testing extreme values from the set of statistics. An example of the use of the statistics is given using spatial‐temporal data on the AIDS epidemic centering on San Francisco. Results indicate that in recent years the disease is intensifying in the counties surrounding the city.
Learning in Single Hidden‐Layer Feedforward Network Models: Backpropagation in a Spatial Interaction Modeling Context
Authors: Gopal Sucharita , Fischer Manfred M.
Published: September 2010

Learning in neural networks has attracted considerable interest in recent years. Our focus is on learning in single hidden‐layer feedforward networks which is posed as a search in the network parameter space for a network that minimizes an additive error function of statistically independent examples. We review first the class of single hidden‐layer feedforward networks and characterize the learning process in such networks from a statistical point of view. Then we describe the backpropagation procedure, the leading case of gradient descent learning algorithms for the class of networks considered here, as well as an efficient heuristic modification. Finally, we analyze the applicability of these learning methods to the problem of predicting interregional telecommunication flows. Particular emphasis is laid on the engineering judgment, first, in choosing appropriate values for the tunable parameters, second, on the decision whether to train the network by epoch or by pattern (random approximation), and, third, on the overfitting problem. In addition, the analysis shows that the neural network model whether using either epoch‐based or pattern‐based stochastic approximation outperforms the classical regression approach to modeling telecommunication flows.
Spatial‐Temporal Spread of the AIDS Epidemic, 1982–1990: A Correlogram Analysis of Four Regions of the United States
Authors: Lam Nina Siu‐Ngan , Fan Ming , Liu Kam‐biu
Published: September 2010

We applied correlogram analysis to county‐level AIDS data of four regions—the Northeast (Delaware, the District of Columbia, Maryland, New Jersey, New York, and Pennsylvania), California, Florida, and Louisiana—for the period 1982–1990 to characterize the spatial‐temporal spread of the AIDS epidemic. Correlograms computed from yearly incidence rates differ substantially among these four regions, revealing regional differences in the spatial patterns and intensity of AIDS spread. A general trend of increasing spread to rural America, however, can still be detected. Contagious spread was predominant in the Northeast throughout the nine‐year period, whereas California was dominated by hierarchical spread through time. The spatial‐temporal changes of AIDS incidence patterns were most drastic in Florida, where the correlograms show hierarchical spread in the early years and then contagious spread in the later years. As a representative region for most other states in the United States, Louisiana has low spatial autocorrelation and no definite spatial pattern of spread. Grouping data into three‐year periods for states with low yearly incidence rates such as Louisiana should help identify the dominant trends for these states. The correlogram results could provide useful insights into the specification of spatial models for AIDS forecasting.
Aggregation and Ecological Effects in Geographically Based Data
Authors: Holt D. , Steel D. G. , Tranmer M. , Wrigley N.
Published: September 2010

Statistics calculated using the means of geographic areas can differ substantially from the corresponding statistics based on data from individuals. Analysts who base their conclusions about individual‐level relationships on area‐level analyses run the risk of committing the ecological fallacy. Statistical models are proposed that capture the essential features of the structure of a population composed of geographically defined groups and can encompass grouping processes and contextual effects. These models are used to show how small effects in the analysis of individual‐level data can be magnified substantially when the corresponding analysis based on aggregated data is carried out. Thus the source of aggregation effects is exposed. While aggregation effects have been studied by many authors, no general approach has been offered to the problem of adjusting an area‐level analysis so as to correct for aggregation effects and hence remove, or at least reduce, the bias that leads to the ecological fallacy. The statistical models proposed are used to provide an approach to this problem. Data from the 1991 U.K. Census of Housing and Population are used to illustrate the size of the aggregation effects and the extent to which the proposed adjustments succeed in their objective.
Locating Vehicle Inspection Stations to Protect a Transportation Network
Authors: Hodgson M. John , Rosing Kenneth E. , Zhang Jianjun
Published: September 2010

We develop a new conceptual approach to locating inspection stations for hazardous vehicles, prevention, and compare it to the previous, punitive, philosophy of the flow‐capturing location model. We implement this preventive protection philosophy with a new mixed integer program that maximizes hazard avoidance by locating a number of inspection stations to detect and remove hazardous vehicles as early in their trips as possible. We test the model's performance and analyze the spatial characteristics of solutions simulating several potential applications. Our computations demonstrate that a relaxed integer‐linear program is overly demanding computationally and that a simple greedy heuristic lacks robustness. We suggest further approaches to developing more powerful and efficient solution methods.
Application of Hurst Resecaling to Geophysical Serial Data
Authors: Outcalt Samuel I. , Hinkel Kenneth M. , Meyer Erika , Brazel Anthony J.
Published: September 2010

The empirical investigation of several geophysical time series indicates that they are composed of segments representing different natural regimes, or periods when events are strongly autocorrelated. Using a data transformation method developed by Hurst, these regimes are differentiated by rescaling the time series and examining the resulting transformed trace for inflections. As regime signals are not completely mixed and have rather long run lengths, Hurst rescaling produces a clustering of extremes of the same sign and elevates the Hurst exponent to values greater than 0.5. These regimes have a characteristic distribution, as defined by the mean and standard deviation, which differ from the statistical characteristics of the complete record. Analysis of sunspot numbers, monthly precipitation records from the midwestern United States, and annual watershed discharge yield regimes that correlate to well‐documented periods of extreme activity. Rescaling appears to be useful in screening time series of unknown characteristics to differentiate periods dominated by regime‐specific physical processes.
An Angular Version of Spatial Correlations, with Exact Significance Tests
Authors: Simon Gary
Published: September 2010

Spatial correlations are replaced by ordinary correlations by projecting the two‐dimensional coordinates of a map onto a single axis making angle θ with the horizontal (east‐west) axis. This calculation permits the use of exact test statistics. Moreover, the correlations can be plotted in polar coordinate form and the significance of the maximum correlation can be tested. The plot is a useful aid in assessing the reasonableness of the isotropy assumption.
Plant Size and Clustering of Manufacturing Activity
Authors: Sweeney Stuart H. , Feser Edward J.
Published: September 2010

Although a growing number of studies emphasize the advantages small firms gain by co‐locating in space, there is little empirical work that directly examines clustering trends by firm size. This paper presents an empirical analysis of the isolated effects of size on clustering patterns of producers in a major manufacturing state in the southeast United States. Recent developments in point process modeling allow us to control for the critical fact that economic activity is, in general, concentrated in space. Our findings suggest that the relationship between establishment size and clustering in North Carolina is roughly characterized by an inverted u‐shape, that is, clustering increases up to some size threshold and then decreases again.
Representing the Shape and Orientation of Destinations in Spatial Choice Models
Authors: Ferguson Mark R. , Kanaroglou Pavlos S.
Published: September 2010

This paper illustrates the importance of spatial unit shape and orientation in spatial choice analysis. It also examines the implications of assuming spatial units to be dimensionless points in this context. Through theory and simulation experiments, it is shown how these aspects cannot be ignored and how the ordinary multinomial logit model applied at the spatially aggregate level is particularly vulnerable to such oversights. The aggregated spatial logit model in the end is recommended as a general formulation which addresses many of these fundamental issues of interest to geographers and regional scientists.
Outmigration from California: The Role of Migrant Selectivity
Authors: Newbold K. Bruce
Published: September 2010

Frey (1995) noted that California generated two, separate outmigration streams. The first stream was composed of “negatively selected” migrants, or those with low education and low income levels. These migrants usually selected destinations in neighboring states such as Washington, Oregon, or Colorado. The second stream was more typical of interstate migration flows. Migrants were typically better educated, had higher incomes and destinations that were more national in scope (positively selected). The purpose of this paper is to evaluate the income selectivity of outmigrants from California. It was hypothesized that poorly educated migrants are negatively self‐selective and the better educated would be positively self‐selective. Using data derived from the 1990 PUMS data file, this paper studies the effects of expected wage differentials in determining the selectivity of outmigrants from California. Self‐selectivity is accounted for in the modeling process via a two‐stage estimation procedure, since estimated returns to migration based on a comparison of individual migrants may be biased due to self‐selection. Results reveal no significant or systematic selectivity of the better educated migrants, while self‐selection was more important among the poorly educated nonmigrants.
Space‐Time and Integral Measures of Individual Accessibility: A Comparative Analysis Using a Point‐based Framework
Authors: Kwan Mei‐Po
Published: September 2010

Conventional integral measures of accessibility, although valuable as indicators of place accessibility, have several limitations when used to evaluate individual accessibility. Two alternatives for overcoming some of the difficulties involved are explored in this study. One is to adapt these measures for evaluating individual accessibility using a disaggregate, nonzonal approach. The other is to develop different types of measures based on an alternative conceptual framework. To pursue the former alternative, this study specifies and examines eighteen gravity‐type and cumulative‐opportunity accessibility measures using a point‐based spatial framework. For the latter option, twelve space‐time accessibility measures are developed based on the construct of a prism‐constrained feasible opportunity set. This paper compares the relationships and spatial patterns of these thirty measures using network‐based GIS procedures. Travel diary data collected in Columbus, Ohio, and a digital data set of 10,727 selected land parcels are used for all computation. Results of this study indicate that space‐time and integral indices are distinctive types of accessibility measures which reflect different dimensions of the accessibility experience of individuals. Since space‐time measures are more capable of capturing interpersonal differences, especially the effect of space‐time constraints, they are more “gender sensitive” and helpful for unraveling gender/ethnic differences in accessibility. An important methodological implication is that whether accessibility is observed to be important or different between individuals depends heavily on whether the measure used is capable of revealing the kind of differences the analyst intends to observe.
Policy Coalitions in the U.S. Congress: A Spatial Duration Modeling Approach
Authors: Pellegrini Pasquale A. , Grant J. Tobin
Published: September 2010

This paper applies spatial duration models to the analysis of cosponsorship coalitions in the U.S. House of Representatives. This approach provides a unique and simultaneous statistical analysis of ideological space (specifically, coalition formation) and geographical space. Typically, duration models are associated with temporal longitudinal data, but recently have been adapted to the spatial domain (Pellegrini and Reader 1996). In this paper, spatial duration models are further adapted to examine ideological space including a consideration of unobserved sources of spatial variation (or omitted variable bias).

We examine two features of cosponsorship coalitions, breadth and clustering. Breadth is defined as the ideological distance between the two most extreme members of the coalition which is an important “signal” to the rest of Congress regarding the scope and broad appeal of the proposed legislation. In contrast, clustering refers to the distance between individual members of a coalition and reveals the tendency, or not, of ideologically similar members of Congress to support various bills. To examine breadth and clustering, we employspatial durationmodels of cosponsorship that permit a multivariate analysis incorporating both the characteristics of members of Congress and the geographical regions they represent.

Results indicate that cosponsorship coalition patterns are primarily determined by the content of the legislation, not the actions of the coalition leadership. While the leadership characteristics of sponsors have a limited effect on cosponsorship breadth, the size of the coalition is the primary determinent. Leadership characteristics also have little effect on cosponsorship clustering. Rather, clustering is due to members' policy preferences, as measured by distance to the coalition leader. In addition, the duration analysis results suggest that geographical proximity between members of Congress “overcomes” ideological distance. Finally, the spatial duration approach is noted as a fruitful methodology for examining explicitly spatial patterns in both ideological or geographical space.
Competitive Location and Pricing on Networks
Authors: Serra Daniel , ReVelle Charles
Published: September 2010

In this paper we consider a location and pricing model for a retail firm that wants to enter a spatial market where a competitor firm is already operating as a monopoly with several outlets. The entering firm seeks to determine the optimal uniform mill price and its servers' locations that maximize profits given the reaction in price of the competitor firm to its entrance. A tabu search procedure is presented to solve the model together with computational experience and an example.
Assessing Regional Crop Irrigation Requirements and Streamflow Availability for Irrigation Development in Saginaw Bay, Michigan
Authors: He Chansheng
Published: September 2010

Spatial and temporal variability of soil, crop, and climate significantly affects the estimates of regional irrigation requirements. This paper incorporates soil association data and multiple‐station, multiple‐year climate data into four simulation models, CERES‐MAIZE, SOYGRO, BEANGRO, and YIELD to account for the spatial and temporal variability of the input parameters in estimating the evapotranspiration rates and irrigation requirements of corn, drybean, soybean, and sugarbeet production in the Saginaw Bay basin, Michigan. The Thiessen method was used to delineate the spatial coverage of the weather stations in the study watershed. The results of the simulated crop irrigation requirements at the soil association level were multiplied by the weights of each soil association area to derive regional irrigation requirements. The availability of streamflow at different exceedence probabilities was evaluated to determine the maximum irrigation area the stream is able to sustain without causing water quality degradation. Through a case study of the Saginaw Bay irrigation development, this paper demonstrates that the spatial and temporal variability of soil, crop, and climate can be well represented in the simulation models to provide more realistic simulation results in support of irrigation decision making.
Investigating DEM Error Patterns by Directional Variograms and Fourier Analysis
Authors: Liu Hongxing , Jezek Kenneth C.
Published: September 2010

In many spatial analyses and GIS applications, a Digital Elevation Model (DEM) is often used to derive a variety of new variables and parameters. Previous research shows that the accuracy of derived variables is affected, not merely by the magnitude of DEM errors and the algorithms applied to derive these variables, but also by the spatial structure of DEM errors. However, the lack of knowledge and understanding of the spatial structure of DEM errors often handicaps the analysis of error propagation.

This paper investigates the spatial autocorrelation and anisotropic pattern of DEM error by using directional variograms in the spatial domain and Fourier analysis in the frequency domain. Based on an empirical study, it is concluded that the spatial autocorrelation pattern of DEM errors is anisotropic and scale‐dependent, and that the maximum direction and range of the autocorrelation depends upon the orientation and wavelength of the terrain features. For a smooth terrain, the magnitude of DEM errors is correlated to surface slope. For a rugged terrain, the elevation values in DEMs tend to be underestimated in ridges, and overestimated in valleys, but the correlation between the DEM error and surface slope is quite low.
Capital Accumulation, Economic Restructuring, and Nonequilibrium Regional Growth Dynamics
Authors: Plummer Paul
Published: September 2010

Recently, there has been a resurgence of interest in explaining the significance and persistence of regional growth differentials. Much of the debate in contemporary political economy has focussed on the relative importance of either “weak” or “strong” competition in regulating movements in prices, profits, and investments both within and between economic sectors and regions. However, little attention has been directed toward developing theoretical models that are capable of evaluating the relative importance of (non) equilibrating forces in determining the long‐run accumulation dynamics of capitalist space economies. In this paper, I develop an approach to modeling regional growth that simultaneously theorizes the link between processes of economic restructuring and regional capital accumulation. I examine the stability properties of this model in order to evaluate the theoretical significance of both equilibrating and nonequilibrating forces in determining the trajectory of regional outputs, profits and employment.
Potential Contributions of Spatial Analysis to Geographic Information Systems for Transportation (GIS‐T)
Authors: Miller Harvey J.
Published: September 2010

Geographic information systems (GIS) are having tremendous impacts on many scientific and application domains. The traditional subfield of spatial analysis is witnessing a major resurgence and enhancement due to GIS andgeographical information science(GISci), an interdisciplinary field focusing on the theory and methodology underlying GIS software. The interdisciplinary field of geographicinformation systems for transportation(GIS‐T)has emerged to focus on the role of GIS in transportaton analysis and planning. This paper suggests the benefits of closer linkages between spatial analysis, GISci, and transportation through a focused review of spatial analytical issues and their potential contributions to GIS‐T. Specifically, this paper reviews the following issues:(i)modifiable areal units;(ii)boundary problems and spatial sampling;(iii)spatial dependence and spatial heterogeneity;and (iv)alternative representations of geographic environments.The discussion highlights the general issues as well as identifies their specific relevance to GIS‐T. In addition, this paper identifies some emerging tools from GISci that can address these spatial analytical issues in GIS‐T.
Accuracy of Count Data Estimated by the Point‐in‐Polygon Method
Authors: Sadahiro Yukio
Published: September 2010

This paper analyzes the accuracy of count data estimated by the point‐in‐polygon method. A point‐in‐polygon interpolation model is proposed, based on a stochastic distribution of points and the target zone, in order to represent a variety of situations. The accuracy of estimates is numerically investigated in relation to the size of the target zone and the distribution of points, and the optimal location of representative points is discussed. The major findings of this paper are as follows: (1) though the relative accuracy of estimates generally increases monotonously with the size of the target zone, the monotoneity is often disturbed by the periodicity in the spatial configuration of source zones and the point distribution; (2) the point‐in‐polygon and the areal weighting interpolation methods have the same accuracy of estimates when points are concentrated in less than 12–15 percent area around the representative point in source zones; (3) the point‐in‐polygon method is not so robust against the locational gap between points and the representative point; (4) the optimal location of representative points is given by the spatial median of points.
The Diurnal Cycle of Regional Commuter Systems: North Wales, 1991
Authors: Akkerman Abraham
Published: September 2010

Places of household residence and places of commuter destination are considered in a contiguous system of subareas constituting a region. An intrahousehold distribution of household members, by subarea of their commuting destination, is considered for each subarea of residence. A household composition matrix is constructed in reference to the average number of commuters to subareas of destination, per household at a subarea of residence, across all subareas. The matrix is a linear transformation from the spatial distribution of households onto the spatial distribution of daytime population, over all subareas of the region. Diurnal population change throughout the region is rendered by this transformation. A linear optimization model extending this transformation formalizes general conditions that relate the diurnal population system to household choice of residence and work. Further, the division of the region into subareas is assumed to be such that the average household in each subarea contains at least one person who remains in the subarea during day and night. Under these conditions, the diurnal system is shown to be analogous to the Leontief input‐output model. An example of eleven counties of North Wales, along with an exogenous area of northwestern England, drawn from the 1991 census of the United Kingdom, illustrates the formal relationships.
Using Multilevel Models to Model Heterogeneity: Potential and Pitfalls
Authors: Duncan Craig , Jones Kelvyn
Published: September 2010

Within the last few years, geographers and researchers in other cognate disciplines with geographic concerns have begun to use multilevel models. While there are several useful existing introductory accounts of these models in the geographical literature, this paper seeks to extend them in three main ways to clarify and emphasize further the substantial opportunities they afford. First, it focuses on how multilevel models are centrally concerned with modeling population heterogeneity as a function of predictor variables. Second, it considers and illustrates a number of specific interpretive issues that can arise when conducting multilevel analyses of place effects. Lastly, it traces some more general, conceptual issues surrounding the use of multilevel models in geographical research. The arguments made are illustrated through an analysis of variations in drinking behavior using data from a typically complex, large‐scale survey; particular attention is given to the inclusion of categorical predictors.
The K‐Function Method on a Network and Its Computational Implementation
Authors: Okabe Atsuyuki , Yamada Ikuho
Published: September 2010

This paper proposes two statistical methods, called the network K‐function method and the network cross K‐function method, for analyzing the distribution of points on a network. First, by extending the ordinary K‐function method defined on a homogeneous infinite plane with the Euclidean distance, the paper formulates the K‐function method and the cross K‐function method on a finite irregular network with the shortest‐path distance. Second, the paper shows advantages of the network K‐function methods, such as that the network K‐function methods can deal with spatial point processes on a street network in a small district, and that they can exactly take the boundary effect into account. Third, the paper develops the computational implementation of the network K‐functions, and shows that the computational order of the K‐function method is O(n2Qlog nQ) and that of the network cross K‐function is O(nQlog U3Q), where nQis the number of nodes of a network.
Measuring Student Perceptions of Blackboard Using the Technology Acceptance Model
Authors: Landry Brett J. L. , Griffeth Rodger , Hartman Sandra
Published: September 2010

Web Enhanced Instruction (WEI) is not intended to replace the traditional classroom setting, but rather to supplement the traditional lecture with course content that can be accessed from campus or the Internet. WEI has the potential to extend the boundaries of traditional classrooms by providing new opportunities for communication and interaction between students and the instructor. While the potential benefits of augmenting the traditional class with WEI have been recognized and discussed, what has remained largely unknown are student reactions to WEI as an addition to the traditional lecture. The Technology Acceptance Model (TAM) has been widely used in the Information Systems research to gather user reactions to information systems. The TAM examines users' perceptions of Usage, Usefulness, and Ease of Use. This research applied the TAM to the academic setting to measure student reactions to Blackboard, the WEI tool used in this study. Using several multivariate methods, results suggest that students (n = 692) found that the Blackboard elements which are associated with Course Content (Course Documents, Lectures, Student Tools, Announcements, and Quizzes) are used more often and are seen as more useful than those items that provide Course Support and communication (Discussion Board, External Web Sites, Faculty Information, and E‐Mail).
Dancing with the Devil: Partnering with Industry but Publishing in Academia*
Authors: Guide V. Daniel R. , Van Wassenhove Luk N.
Published: September 2010

We believe that partnering with industry can lead to research that is relevant, rigorous, and refreshing. Our experiences show that the potential benefits of partnering with industry are enormous, but that this is not an easy route for academics interested in operations research modeling or empirical methods. The need for grounded business research is greater now than ever, and, while academics have made great progress, there are still numerous opportunities to demonstrate the relevance of our research. We discuss how to establish industry contacts, identify fruitful academic—industry projects, and publish the resulting research.
Returnee Entrepreneurs, Science Park Location Choice and Performance: An Analysis of High–Technology SMEs in China
Authors: Wright Mike , Liu Xiaohui , Buck Trevor , Filatotchev Igor
Published: September 2010

Building on an asset complementarity perspective, human capital and social capital measures are used to examine the science park location decisions of returnee entrepreneurs and the performance of their ventures. The study uses a unique, hand–collected data set of 349 SMEs from Zhongguancun Science Park in China, including 53 SMEs from locations administered by universities. The article considers the antecedents of university and nonuniversity science park location and firm growth with a view to drawing conclusions that go beyond the specific context of Beijing and China. Its findings include the tendency for returning entrepreneurs with academic knowledge in the form of patents transferred from abroad to locate in nonuniversity science parks, and for those with previous firm ownership abroad to choose university science parks. The firms of returnees with patents from abroad enjoyed stronger employment growth in nonuniversity science parks and those with commercial experience abroad with MNCs performed better in university science parks. This evidence is consistent with the view that returning entrepreneurs seek complementary (academic and commercial) assets in their location decisions, although some inconsistencies with this view are also discussed.
Toward a Theory of Familiness: A Social Capital Perspective
Authors: Pearson Allison W. , Carr Jon C. , Shaw John C.
Published: September 2010

In the search for ways in which the family firm context is unique to organizational science, the construct of “familiness” has been identified and defined as resources and capabilities that are unique to the family's involvement and interactions in the business. While identification and isolation of a construct unique to family firms is both groundbreaking and important for family firm research, it is also important that the development of the construct continues to be examined from complementing theoretical viewpoints. As such, we set out to review the development of the familiness construct and identify its dimensions. We also explore the nomological relationships of the construct based on a social capital theory perspective and offer a theory of familiness.
Can Anatomical Left Ventricular Mass Be Estimated Reliably by M‐Mode Echocardiography? A Clinicopathological Study of Ninety‐Three Patients
Authors: BACHENBERG TIMOTHY C. , SHUB CLARENCE , HAUCK ARTHUR J. , EDWARDS WILLIAM D.
Published: September 2010

To evaluate the accuracy ofM‐mode echocardiography in the assessment of left ventricular mass, we compared various echocardiography‐derived regression equations for left ventricular mass to postmortem left ventricular weights in 93 patients (mean age 68 ± 11 years) who had autopsy within 30 days of technically adequate two‐dimensional guided M‐mode echocardiography and who had normal left ventricular shape. The left ventricle was enlarged in 36 patients (39%) and was involved by chronic ischemic disease in 48 patients (52%). Only a modest correlation was found between M‐mode echocardiography and anatomical left ventricular mass (range of correlation coefficients, 0.58 to 0.67). Each echocardiography formula demonstrated increasing deviations as left ventricular mass increased. A previously suggested correction formula lessened overestimation, but considerable data dispersion remained. Regional wall‐motion abnormalities, present in 22%, did not affect the correlation. We conclude that M‐mode echocardiography, performed with standard methods, does not reliably estimate anatomical left ventricular mass, especially in patients with large hearts. (ECHOCARDIOGRAPHY, Volume 8, January 1991)
Assessment of Chest Pain by Nuclear Cardiology Techniques
Authors: ITTI R. , BONTEMPS L.
Published: September 2010

This article reviews the nuclear cardiology techniques which can be used to assess chest pain. Nuclear techniques can potentially give valuable information on the location and extent of myocardial perfusion abnormalities, the assessment of myocardial viability, and/or presence of myocardial necrosis and the effects, both regional and global, of myocardial ischemia on myocardial function. The article reviews specific tests available and their indications and indicates the usefulness of these techniques for the clinician managing myocardial ischemia. (ECHOCARDIOGRAPHY, Volume 8, January 1991)
Speckle Tracking for Assessment of Cardiac Motion and Dyssynchrony
Authors: Kawagishi Tetsuya
Published: September 2010

Dyssynchrony estimation using echocardiography is increasingly used as a quantitative tool to qualify candidates for cardiac resynchronization therapy (CRT) and evaluate its effect post procedure. Conventionally, tissue Doppler imaging (TDI) has been used for this application, but its utility and accuracy are limited by the angle of incidence‐dependent nature of Doppler velocity measurement. Recently, speckle tracking technology applied to B‐mode images has been developed for wall motion analysis including dyssynchrony estimation. Regional motion is tracked by observing the movement of two‐dimensional (2D) speckle patterns in ultrasound images. Three‐dimensional (3D) speckle tracking is also possible and can be used to evaluate 3D cardiac motion of the entire left ventricle. Speckle tracking can provide assessment of regional strain and dyssynchrony in cardiac motion for more objective diagnosis.
Comparison of Real Time Two‐Dimensional with Live/Real Time Three‐Dimensional Transesophageal Echocardiography in the Evaluation of Mitral Valve Prolapse and Chordae Rupture
Authors: Manda Jayaprakash , Kesanolla Saritha Kumari , Hsuing Ming Chon , Nanda Navin C. , Abo‐Salem Elsayed , Dutta Rajarshi , Laney Charles Allen , Wei Jeng , Chang Chung‐Yi , Tsai Shen‐Kou , Hansalia Sachin , Yin Wei‐Hsian , Young Mason S.
Published: September 2010

We compared live/real time three‐dimensional transesophageal echocardiography (3D TEE) with real time two‐dimensional transesophageal echocardiography (2D TEE) in the assessment of individual mitral valve (MV) segment/scallop prolapse and associated chordae rupture in 18 adult patients with a flail MV undergoing surgery for mitral regurgitation. 2D TEE was able to diagnose the prolapsing segment/scallop and associated chordae rupture correctly in only 9 of 18 patients when compared to surgery. In three of these, 2D TEE diagnosed an additional segment/scallop not confirmed at surgery. In the remaining nine patients, surgical findings were missed by 2D TEE. On the other hand with 3D TEE, the prolapsed segment/scallop and associated ruptured chords correlated exactly with the surgical findings in the operating room in 16 of 18 patients. The exceptions were two patients. In one, 3D TEE diagnosed prolapse and ruptured chordae of the A3 segment and P3 scallop, while the surgical finding was chordae rupture of the A3 segment but only prolapse without chordae rupture of the P3 scallop. In the other patient, 3D TEE diagnosed prolapse and chordae rupture of P1 scallop and prolapse without chordae rupture of the A1 and A2 segments, while at surgery chordae rupture involved A1, A2, and P1. This preliminary study demonstrates the superiority of 3D TEE over 2D TEE in the evaluation of individual MV segment/scallop prolapse and associated ruptured chordae.
What is Queer About Sex?: Expanding Sexual Frames in Theory and Practice
Authors: IASENZA SUZANNE
Published: September 2010

Psychotherapists often believe if couples improve their communication and emotional dynamics, good sex follows. In practice we often find otherwise and have many questions about how to proceed to work with sexuality issues more directly. This paper presents the many challenges working with sex including the following: the fluidity and multidimensionality of sex and gender, the incongruities and paradoxes in sexual behavior, thoughts, attractions, feelings, and sensations, and the powerful feelings, impasses, surprises, and confusion therapists often experience doing the work. In essence, what is queer about sex? Using the couple as client, expansive ways of thinking and working with sexuality are presented including the development of inclusive models of sex, gender, and sexual response, as well as new approaches to standard sex therapy techniques such as sexual history‐taking, redefining sex, and sensate focus. Techniques are presented with an emphasis on the therapist's use of self as sexual change agent including integrating multiple theoretical perspectives (psychodynamic, systemic, and cognitive‐behavioral), co‐creating a safe treatment frame, and how to intervene within the cognitive, affective, behavioral, somatic, and discursive realms.
Human Rights Forum: Climate Change and Human Rights in Bangladesh
Authors: Rahman Siddiqur
Published: September 2010

Gretchen E Schafft is contributing editor of “Human Rights Forum,” the AAA Committee for Human Rights column in Anthropology News.