bluuebunny/crossref_metadata_2025 huggingface dataset:
Urban Traffic Flows and Fourier Transforms
Authors: Dendrinos Dimitrios S.
Published: September 2010

The purpose of this paper is first, to present some evidence indicative of a rough daily periodicity in traffic counts at a cross‐section of an urban road accompanied by a considerable amount of seemingly random additional variation; and second, to attempt an accounting through Fast Fourier Transform and power spectrum density functions of this additional variation beyond the rough daily cycle. Reasons behind the macroscopic variable's dynamic behavior are provided. Relatively extensive traffic counts make them especially suited for investigating various dynamic behaviors, including possibly nonperiodic (chaotic) patterns.
Heterogeneity of Attribute Sampling Error in Spatial Data Sets
Authors: Griffith Daniel A. , Haining Robert , Arbia Giuseppe
Published: September 2010

This paper considers the standard error of the estimate of the mean of a spatially correlated variable in the case where data are obtained by a process of random sampling. Two distinct mean estimation problems are identified: estimating the area mean and estimating the population mean. Methods are described for obtaining standard error estimates in the two cases and, within the limits of publicly available information, the methods are implemented on average household income data at the census tract scale for Syracuse, New York. The purpose of the paper is to draw attention to issues of data precision in relation to sampled geographic information on averages and in particular to consider the problems of estimating standard errors using such data. The paper also examines the extent to which standard errors vary between census tracts.
Generalized Additive Models, Graphical Diagnostics, and Logistic Regression
Authors: Jones Kelvyn , Wrigley Neil
Published: September 2010

Generalized additive models (GAMs), although little known in geographical analysis, have considerable utility. In particular, they allow the conventional linear relationships of multiple regression to be generalized to permit a much broader class of nonlinear, but still additive, relationships between response and predictor variables. This paper illustrates how GAMs can be extended to the important case of logistic regression with binary response. Details of the distinctive form of logistic regression GAMs are provided, and appropriate means of estimation are outlined. The paper provides the first use, in the context of a logistic regression GAM, of the expansion method of assessing parameter variation. These techniques are illustrated by a reanalysis of information on hydrocarbon exploration wells drilled in south‐central Kansas.
Subdividing National Territories: The Drive to Live in a Political Community Whose Boundaries Are Congruent with the Cultural Community
Authors: Keyfitz Nathan
Published: September 2010

Two ideals have dominated world politics for two hundred years. In one, conveniently called liberal, there are no real differences among peoples, and that they speak different languages and have different religions should not be allowed to affect their collaboration in a national state; the United States with its multiethnic, multinational composition has been the concrete expression of this. The opposite ideal, here called nationalist or reactionary, was that language and religion do matter and that people ought to be able to live in a political community whose boundaries reflect that; Iran is an extreme case of this. If the liberal ideal goes back to the eighteenth‐century Enlightenment, nationalism was given its impetus in nineteenth‐century Romanticism. Nationalism has dissolved successively the British, Dutch, and French empires, and then gone on toward breaking down the constituents into which these separated. Despite attempted suppression of breakaway movements by better armed forces of existing states, the number of states in the world has more than doubled since the end of World War II. Only recognized governments can become members of official international bodies. Despite a lack of legitimacy, no right to speak in the councils of the United Nations, and no legal access to arms, the forces of separation seem on the rise, those of union of multicultural nations, on the decline. It is too early to predict ultimate victory for one ideal or the other.
Feminism, Praxis, and Human Geography
Authors: Staeheli Lynn A. , Lawson Victoria A.
Published: September 2010

In this paper, we discuss the methodological implications of combining feminist and geographic research. In feminist research efforts, theory, method, and purpose of research are inextricable. We examine the meaning of this blending for the language, conceptualizations, methods, and scale used in feminist geographic research. Through feminist geographic research, we can build a continuity of women and men as feminist writers inside the academy and in the community. The goal of this more inclusive research and knowledge is the transformation of gendered power relations.
The Artifice of Conviction, or, An Internal Geography of Responsibility
Authors: Hannah Matthew , Strohmayer Ulf
Published: September 2010

This essay addresses one of the defining characteristics of debates within human geography and across the social sciences during the last ten years: the encounter between traditional and postmodern discourses. It is argued that at least one issue has been unduly neglected: the material fact of groundless arguments. Alternatively portrayed as the father of all evils or celebrated as the liberation of scientific creativity, the groundlessness of arguments has to happen before it can be interpreted. The essay discusses examples of texts that accept the groundless happening of their claims head on. Through these examples, it is argued that possible lessons from the encounter with the so‐called “postmodern challenge” include reconsidered notions of both scientific responsibility and argumentative materiality.
Space‐Time Synergetics in Innovation Diffusion: A Nested Network Simulation Approach
Authors: Nijkamp Peter , Reggiani Aura
Published: September 2010

The relevance of evolutionary dynamics theories for investigating the development of sociotechnical systems has recently been recognized. In this framework the logistic growth model is considered by many scientists as an extremely appropriate framework that is able to interpret the dynamics of innovation diffusion.

Starting from recent results in the literature on technological dynamics, the present paper focuses on backgrounds leading to different shapes of the conventional logistic function. By embedding these motives in the socio‐attitudinal context of the system at hand, the present paper tries to give a new interpretation for the rapid/slow “take off” and dynamics of a given innovation in a spatial setting. In particular, a nested logistic dynamic model is developed here, with particular emphasis on the dynamic growth rate of the logistic function expressing—by means of an accessibility cost function—the preference intensity concerning a given innovation for a certain region/country.

Finally, various simulation experiments are carried out for the case of both a two‐dimensional and a four‐dimensional network. The possibility of both stable and unstable diffusion patterns, depending on the parameter values in the nested “attitudinal” dynamic function, is also investigated.
Markov Models of Inertia and Dynamism on Two Contiguous Ohio Landscapes
Authors: Boerner Ralph E. J. , DeMers Michael N. , Simpson John W. , Artigas Francisco J. , Silva Alejandra , Berns Leslie A.
Published: September 2010

This study examined landcover change during 1940–1988 in two contiguous landscapes of approximately 12,400 hectares in central Ohio, USA: an inertial till plain area and a more dynamic moraine area. Agriculture dominated both landscapes throughout, however, the cover of natural vegetation and urban‐suburban development increased over time on the moraine while natural vegetation decreased and agriculture increased on the till plain. Markov process models for landcover change were constructed for three 14–17‐year time intervals and for the entire forty‐eight‐year study period. Probabilities of self‐replacement for agricultural lands (0.91–0.97) were higher and those for forests (0.54–0.65) lower than those reported for other landscapes. Predictions of landcover percentages for fifty years in the future were made using Markov process models derived from actual cover changes in 1940–1957, 1971–1988, and 1940–1988. All three models produced similar predictions for the inertial till plain area. In contrast, the three models' predictions differed considerably for the moraine area. Only the 1971–1988 transition matrix was sensitive to increases in urbanization and reforestation which began on the moraine in the 1970s. These results indicate that reliance on lengthy study intervals and net rates of change can obscure spatial and temporal patterns of landcover change that are caused by natural and socioeconomic factors operating on shorter time scales.
Geographically Weighted Regression: A Method for Exploring Spatial Nonstationarity
Authors: Brunsdon Chris , Fotheringham A. Stewart , Charlton Martin E.
Published: September 2010

Spatial nonstationarity is a condition in which a simple “global” model cannot explain the relationships between some sets of variables. The nature of the model must alter over space to reflect the structure within the data. In this paper, a technique is developed, termed geographically weighted regression, which attempts to capture this variation by calibrating a multiple regression model which allows different relationships to exist at different points in space. This technique is loosely based on kernel regression. The method itself is introduced and related issues such as the choice of a spatial weighting function are discussed. Following this, a series of related statistical tests are considered which can be described generally as tests for spatial nonstationarity. Using Monte Carlo methods, techniques are proposed for investigating the null hypothesis that the data may be described by a global model rather than a non‐stationary one and also for testing whether individual regression coefficients are stable over geographic space. These techniques are demonstrated on a data set from the 1991 U.K. census relating car ownership rates to social class and male unemployment. The paper concludes by discussing ways in which the technique can be extended.
Residence and Workplace Relocation: A Bivariate Duration Model Approach
Authors: van Ommeren Jos , Rietveld Piet , Nijkamp Peter
Published: September 2010

Different economic theories suggest that residential and labor market relocations are mutually related. This has been verified in various empirical studies. We analyze this relationship based on a bivariate duration model of residential and labor market mobility. This specification is motivated by a search model that allows for simultaneous search on the labor and housing market, taking commuting costs into account. We investigate this relationship by using information on job and residence durations. In order to be able to analyze properly empirical duration data, we derive the statistical distributions of interest. Our empirical results based on a Dutch sample of full‐time employed workers show that residential and labor market mobility depend positively on one another, which is in line with the theoretical search model presented. Moreover, we present easy‐to‐interpret measures for this dependency.
A Note on the Extremities of Local Moran's Iis and Their Impact on Global Moran's I
Authors: Tiefelsdorf Michael , Boots Barry
Published: September 2010

By defining local Moran's Ii as a ratio of quadratic forms and making use of its overall additivity to match global Moran's I, we can identify spatial objects with a strong impact on global Moran's I. First, we concentrate on the spatial properties of local Moran's Ii expressed by the local linkage degree. Depending on whether we use the W‐ or C‐coding of the spatial connectivity matrix, the variance of local Moran's Ii for a small local linkage degree will be either large or small. Note that spatial objects associated with a local Moran's Ii with a large variance affect the global statistic much more than spatial objects associated with a local Moran's Ii with a small variance. Counterintuitively, global Moran's I defined in the W‐coding is most influenced by spatial objects with a small number of spatial neighbors. In contrast, spatial objects with a large number of spatial neighbors exert more impact on global Moran's I setup in the C‐coding. Second, we investigate the impact of the empirical data on local Moran's Ii and show that local Moran's Ii will only be significant for extreme absolute residuals at and around the reference location. Clusters of average regression residuals cannot be detected by local Moran's Ii. Consequently, spatial cliques of extreme residuals contribute more to significance tests on global autocorrelation.
Parameterization and Visualization of the Errors in Areal Interpolation
Authors: Cockings Samantha , Fisher Peter F. , Longford Mitchel
Published: September 2010

Areal interpolation involves the transfer of data from one zonation of a region to another, where the two zonations of space are geographically incompatible. By its very nature this process is fraught with errors. However, only recently have there been specific attempts to quantify these errors. Fisher and Langford (1995) employed Monte Carlo simulation methods, based on modifiable areal units, to compare the errors resulting from selected areal interpolation techniques. This paper builds on their work by parameterizing and visualizing the errors resulting from the areal weighting and dasymetric methods of areal interpolation. It provides the basis for further research by developing the methodology to produce predictive models of the errors in areal interpolation. Random aggregation techniques are employed to generate multiple sets of source zones and interpolation takes place from these units onto a fixed set of randomly generated target zones. Analysis takes place at the polygon, or target zone level, which enables detailed analysis of the error distributions, basic visualization of the spatial nature of the errors and predictive modeling of the errors based on parameters of the target zones. Correlation and regression analysis revealed that errors from the areal weighting technique were related to the geometric parameters of the target zones. The dasymetric errors, however, demonstrated more association with the population or attribute characteristics of the zones. The perimeter, total population, and population density of the target zones were shown to be the strongest predictive parameters.
A New Algorithm for Graph‐theoretic Nodal Accessibility Measurement
Authors: Lee Keumsook , Lee Hee‐Yeon
Published: September 2010

Accessibility is a useful concept in the study of the spatial structure of a region, if it can be calibrated appropriately. While graph‐theoretic analysis has been used widely as a measurement scheme for the nodal accessibility in various transport networks, several limitations have been pointed out in the existing graph‐theoretic accessibility measurements. This study proposes a new algorithm for deriving the nodal accessibility measure, as an attempt to improve the conventional graph‐theoretic accessibility measurements. Corrections are made in such a way that irrelevant loops are excluded and relevant indirect connection paths are included selectively. In particular, the new algorithm is developed for intraurban subway networks, and includes the characteristics of intraurban subway traffic behavior. The concept of inconvenience of transfer is introduced, which is one of the most influential factors in the intraurban subway traffic. Nodal differentiation is allowed, if the nodes play different roles in the travel behavior and eventually in the accessibility. For this purpose, we employ a weighting procedure, according to which the influence of transfer on a sequence of linkages is taken into account. The new accessibility measurement scheme is then applied to the Seoul subway network. Here GIS techniques are utilized to generate accessibility surfaces from the discrete nodal accessibility values, and the changes in the spatial structure of the nodal accessibility are analyzed. Finally, based on the resulting changes in the spatial structure of accessibility in the subway network, the direction of changes in the land value and the land use pattern in Seoul is discussed.
Clustering and Dispersion of Duopolists in a Linear Market
Authors: Pitts Timothy C. , Boardman John P.
Published: September 2010

The locations that two sellers will choose in a linear market has long been of interest. It is well accepted that firms will tend to cluster in the center of the market as long as demand for the product is inelastic and the market area is bounded. It has also been stated that clustering is less strong as demand becomes more elastic, but questions of when this dispersion occurs and what affects it remain to be addressed. This paper further explores clustering in spatial duopoly as elastic demand is allowed. Results indicate that the clustering behavior of sellers is related to the price of the product they sell, the cost to the consumer of acquiring the product, and the elasticity of demand. Locations of sellers in a linear market will lie between the median location and the quartiles as these parameters vary.
Models for Spatial Weights: A Systematic Look
Authors: Bavaud François
Published: September 2010

General properties of spatial weights models, in particular Markovian properties, are systematically investigated. The role of stationary spatial distribution, interpretable as an importance‐centrality or prominence index, is emphasized. Spatial interaction models, and among them the gravity model, are classified with respect to the time reversal and aggregation invariance properties obeyed by the associated spatial weights. Nine examples, involving connectivity, flows and distance decay analysis, integral geometry, and Dirichlet‐Voronoi tessellations illustrate the main concepts, with a particular geometrical emphasis, and show how traditional, heuristic ingredients aimed at defining spatial weights can be recovered from general models.
Modeling Distance Decay Effects in Web Server Information Flows
Authors: Murnion S. , Healey R. G.
Published: September 2010

Previous studies have shown that there is a direct correlation between the popularity of a medium and the cost in transmitting information through that medium. On this basis the World Wide Web may become more important as a mass medium than radio and television. Yet despite the enormous growth in Internet information and Internet‐supported businesses, there has been, as yet, little in the way of quantitative spatial analysis of information flows on the WWW. One major issue is whether or not distance influences the web sites that a user may visit. If distance is a factor, then the location of servers delivering content becomes important. In this paper an analysis of information flows from U.K. academic web servers to the rest of the world is carried out. Using a UNIX utility called ping, the average time taken for a defined amount of information to travel between the United Kingdom and sixty‐six other countries across the Internet was measured. This time measurement known as latency is used as a measure of distance on the Internet. The latency measurements are combined with counts of visitors from each of these countries to approximately one hundred U. K. academic WWW servers and used to build a simple gravity model of WWW information flows. The latency measurements between the United Kingdom and the other countries were gathered over a week in 1996. The counts of visitors relate to the total number of visits to the web servers over various time‐scales for the years 1995 and 1996. We make the assumption that the distance measurements used are relevant to the visit counts. We also assume that all visitors from the .edu domain are geographically located in the United States. The gravity model is used to determine the effect of Internet distance on the number of expected visits to a web server. The study shows that latency values are a useful metric for measuring Internet distance. The results also demonstrate that the number of visitors to a web site falls off with distance on the Internet, as measured by latency values.
Spatial Analysis in Physical Geography and the Challenge of Deterministic Uncertainty
Authors: Phillips Jonathan D.
Published: September 2010

The application of complex and nonlinear dynamical systems (NDS) theory in physical geography and geosciences has proceeded through several stages, and has recently entered a phase where field‐testable hypotheses and historical or mechanistic explanations are being generated. However, there are some fundamental challenges. It seems clear that chaos and dynamical self‐organization are present, and may be common in earth surface systems, and that these phenomena have spatial manifestations in the landscape. However, NDS theory and methods have been formulated primarily in the temporal domain and are typically ill‐suited to real‐world spatial data. Spatial analytical methods are not generally capable of distinguishing deterministic complexity and uncertainty from noise. Thus, the detection of the signals of complex deterministic dynamics in real landscapes and spatial data is a major challenge. Entropy‐based methods of spatial analysis can be directly linked to nonlinear dynamics, and are at present the best available method to approach this problem. However, there is evidence in the spatial analysis literature suggesting that development of techniques to detect deterministic uncertainty is possible. Pending such a break‐through, three general approaches are described, based on spatial analysis of chronosequences, the characteriziation of changes in spatial structure over time, and the spatial‐domain testing of specific hypotheses relevant to deterministic uncertainty. Current trends generally suggest a shift in mathematical modeling and spatial analysis in physical geography away from traditional determinism toward approaches that incorporate locational, historical, and scale contingency.
Capital Assistance for Small Firms: Some Implications for Regional Economic Welfare
Authors: Felsenstein Daniel , Fleischer Aliza
Published: September 2010

This paper analyzes the role of finance capital in regional economic development. A cost‐benefit approach is invoked in order to estimate the welfare impacts of a regional loan and guarantee program for small firms in Israel. Program‐created employment is treated as a benefit and an employment account that separates net from gross employment, is presented. An estimate of net wage benefits is then derived. This involves adjusting wages across different earnings classes in order to account for the variation in opportunity costs of labor at different levels. The estimation of costs includes the opportunity costs of capital, administration, default, and tax‐raising costs. Results point to substantial regional welfare effects. We stress the need to account for changing regional economic structure in this kind of evaluation framework.
Closed‐Form Maximum Likelihood Estimates of Nearest Neighbor Spatial Dependence
Authors: Pace R. Kelley , Zou Dongya
Published: September 2010

Models of n2potential spatial dependencies among n observations spread irregularly over space seem unlikely to yield simple structure. However, the use of the nearest neighbor leads to a very parsimonious eigenstructure of the associated adjacency matrix which results in an extremely simple closed form for the log determinant. In turn, this leads to a closed‐form solution for the maximum likelihood estimates of the spatially autoregressive and mixed regressive spatially autoregressive models. With the closed‐form solution, one can find the neighbors and compute maximum likelihood estimates for 100,000 observations in under one minute. The model has theoretical, pedagogical, diagnostic, modeling, and methodological applications. For example, the model could serve as a more enlightened null hypothesis for geographic data than spatial independence.
Economic and Environmental Policy Analysis of the Flumen‐Monegros Irrigation System in Huesca, Spain
Authors: Feijoó M. Luisa , Calvo Elena , Albiac José
Published: September 2010

This article describes a behavioral model of the Flumen‐Monegros irrigation area (Spain) and presents the results from the model simulation under various policy scenarios. The model combines agronomic, economic and policy information in a framework built using linear programming and crop growth simulation techniques. An important feature of the model is the classification of crop acreage in various types of soils which have different productive potential. The objective function maximizes net margins of crops and includes direct payments of the Common Agricultural Policy (CAP). The crop activities covered in the model are the main crops cultivated in the area (fallow, wheat, barley, corn, sunflower, alfalfa, rice, other crops, and CAP set‐aside). To validate the model, the results on cropland utilization obtained from the model have been compared with actual cropland utilization, concluding that the model closely approximates the actual data. The model is used to characterize the behavior of the irrigation area under three scenarios which reflect likely changes in agricultural and environmental policies: removal of direct payments, increase in water prices, and reduction of fertilizer use. The results show the large impact of these three scenarios on farmers' production decisions: the elimination of direct payment reduces net margin almost by half; prices corresponding to full recovery of water costs reduce significantly the cultivated acreage; and the reduction in fertilizer use causes a fall of 23 percent in net margins.
Exploring Spatial Process Dynamics Using Irregular Cellular Automaton Models
Authors: O'Sullivan David
Published: September 2010

Cellular automaton models have enjoyed popularity in recent years as easily constructed models of many complex spatial processes, particularly in the natural sciences, and more recently in geography also. Most such models adopt a regular lattice (often a grid) as the basis for the spatial relations of adjacency that govern evolution of the model. A number of variations on the cellular automaton formalism have been introduced in geography but the impact of such variations on the likely behavior of the models has not been explored. This paper proposes a method for beginning to explore these issues and suggests that this is a new approach to the investigation of the relationships between spatial structure and dynamics of spatial processes. A framework for this exploration is suggested, and details of the required methods and measures are provided. In particular, a measure of spatial pattern—spatial information—based on entropy concepts is introduced. Initial results from investigation along the proposed lines are reported, which suggest that a distinction can he made between spatially robust and fragile processes. Some implications of this result and the methodology presented are briefly discussed.
An Approximation for the Rank Adjacency Statistic for Spatial Clustering with Sparse Data
Authors: Ekwaru John Paul , Walter Stephen D.
Published: September 2010

The rank adjacency statistic D provides a simple method to assess regional clustering. It is defined as the weighted average absolute difference in ranks of the data, taken over all possible pairs of adjacent regions. In this paper the usual normal approximation to the D statistic is found to give inaccurate results if the data are sparse and some regions have tied ranks. Adjusted formulae for the moments of D that allow for the existence of ties are derived. An example of analyses of sparse mortality data (with many regions having no deaths, and hence tied ranks) showed satisfactory agreement between the adjusted formulae and the empirical distribution of the D statistic. We conclude that the D statistic, when used with adjusted moments, provides a valid approximate method to evaluate spatial clustering, even in sparse data situations.
Modeling Air Quality in Urban Areas: A Cell‐Based Statistical Approach
Authors: Guldmann Jean‐Michel , Kim Hag‐Yeol
Published: September 2010

Statistical regression models are presented that explain the observed variations, across urban areas, in the concentrations of two major pollutants, ozone and carbon monoxide. Model specification and estimation are based on an explicit and new spatial framework derived from the theoretical concept of well‐mixed cells, whereby the basic Fickian system of diffusion equations is integrated over the regional space partitioned into a grid of large cells. The concentration in each cell results from the balance of pollutant flows into and out of this cell and of pollutant emissions and removal within that cell, and is expressed as the sum of two concentration contributions: (1) the local effect, dependent upon pollution‐related factors around the measuring station, and (2) the regional effect, dependent upon pollutant flows originating outside the local area. A large database is developed, making extensive use of GIS technology, to spatially relate such data as pollution measurements, meteorological factors, land‐use characteristics, census socioeconomic data, and major highway network characteristics. The results confirm the appropriateness of the well‐mixed cell framework, are in line with general knowledge regarding the determinants of ozone and carbon monoxide concentrations, and clarify the role of transportation, residential fuel use, economic activities, natural environments, and meteorological factors such as temperature and solar radiation. About SO percent of the variations in concentrations are explained by these models. Several areas of further research are outlined.
A Statistical Method for the Detection of Geographic Clustering
Authors: Rogerson Peter A.
Published: September 2010

Kernel‐based, smoothed estimates of spatial variables are useful in exploratory analyses because they yield a clear visual image of geographic variability in the underlying variable. In this paper I suggest an approach for assessing the significance of peaks in the surface that result from the application of the smoothing kernel. The approach may also be thought of as a method for assessing the maximum among a set of suitably defined local statistics. Local statistics for data on a regular grid of cells are first defined by using a Gaussian kernel. Results from integral geometry are then used to find the probability that the maximum local statistic (M) exceeds a given critical value (M). Approximations are provided that make implementation of the approach straightforward. Future work will address several other issues associated with local statistics that have been defined in this way, including edge effects, and the effects of global spatial autocorrelation on the choice of critical value.
Multidimensional Sequence Alignment Methods for Activity‐Travel Pattern Analysis: A Comparison of Dynamic Programming and Genetic Algorithms
Authors: Joh Chang‐Hyeon , Arentze Theo A. , Timmermans Harry J.P.
Published: September 2010

Quantitative comparisons of space‐time activity‐travel patterns have been made at length in regional science. Traditionally, Euclidean Hamming distances have been widely used to measure the similarity between activity‐travel patterns that involve several attribute dimensions such as activity type, location, travel mode, accompanying person, etc. Other techniques, such as pattern recognition in signal processing theory, have also been introduced for this purpose. All these measures, however, lack the ability to capture the sequential information embedded in activity‐travel patterns. Recently, the sequence alignment methods (SAMs), developed in molecular biology that are concerned with the distances between DNA strings, have been introduced in time use research. These SAMs do capture the similarity of activity‐travel patterns, including sequential information, but based on a single attribute only. Unfortunately, the extension of the unidimensional SAMs to a multidimensional method induces the problem of combinatorial explosion. To solve this problem, this paper introduces effective heuristic methods for the comparison of multidimensional activity‐travel patterns. First, following a brief review of existing measures of activity‐travel pattern comparison, the problem of multidimensional sequential information comparison and the combinatorial nature of the method are discussed. The paper then develops alternative multidimensional SAMs employing heuristics based on dynamic programming and genetic algorithms, respectively. These heuristic SAMs are compared using empirical activity‐travel pattern data. The paper ends by discussing avenues of future research.
Spatiotemporal Analysis of Surface Changes by Tessellations
Authors: Sadahiro Yukio
Published: September 2010

This paper develops a method for analyzing the change of surface, a continuous function defined over the two‐dimensional space. The surface change is represented by a scalar field in a spatiotemporal region. The region is divided into subregions called hills and waves which are based on the local form of the surface. They are both three‐dimensional tessellations of the spatiotemporal region, and provide an overview of the surface change. To summarize the tessellations, four operations are proposed: section, projection, merging, and graph representation. They extract useful information from tessellations to describe the structure of surface change. To test the validity of the method, the change of a retail cluster in Shinjuku and Shibuya area in Tokyo is analyzed. The empirical study yields some interesting findings that help us understand changes in the spatial structure of retailing.
Factors Affecting the Ability to Detect Spreadsheet Errors
Authors: Howe Harry , Simkin Mark G.
Published: September 2010

The extensive computational and formatting capabilities of today's spreadsheets enable users to create sophisticated analytical models with professionally formatted outputs. But good‐looking reports can mask a host of input errors, formula mistakes, and computational problems. This article examines the subject of spreadsheet error detection in detail and describes an experiment designed to identify those factors influencing the error‐detection capabilities of a sample of spreadsheet users.
Interorganizational Governance Value Creation: Coordinating for Information Visibility and Flexibility in Supply Chains*
Authors: Wang Eric T. G. , Wei Hsiao‐Lan
Published: September 2010

More thoroughly understanding how interorganizational governance value can be created by information technology and other governance mechanisms is critical for supply chain management. Based primarily on transaction‐cost economics and supplemented by the resource‐based view, this study investigates how interorganizational governance (i.e., relational governance and virtual integration) can create value (i.e., information visibility and supply chain flexibility) in the supply chain context. The findings show that both relational governance and virtual integration benefit information visibility. Those results also support both direct and indirect (via information visibility) effects of relational governance on supply chain flexibility. Although failing to affect supply chain flexibility directly, virtual integration can still improve supply chain flexibility with its ability to enhance information visibility. Thus, interorganizational governance mechanisms emphasizing both control and collaboration can influence the gain from collaboration‐specific capabilities, leading to the competitive advantage of a supply chain. The results of the study suggest that firms can gain greater supply chain flexibility within existing interfirm relationships by enhancing information visibility through virtual integration and relational governance.
Entrepreneurship in Emerging Economies: Where Are We Today and Where Should the Research Go in the Future
Authors: Bruton Garry D. , Ahlstrom David , Obloj Krzysztof
Published: September 2010

Emerging economies are characterized by an increasing market orientation and an expanding economic foundation. The success of many of these economies is such that they are rapidly becoming major economic forces in the world. Entrepreneurship plays a key role in this economic development. Yet to date, little is known about entrepreneurship in emerging economies. This introductory article to the special issue on entrepreneurship in emerging economies examines the literature that exists to date in this important domain. It then reviews the research that was generated as part of this special issue on this topic. The article concludes with a discussion of the critical future research needs in this area.
Corporate Entrepreneurship as Resource Capital Configuration in Emerging Market Firms
Authors: Yiu Daphne W. , Lau Chung–Ming
Published: September 2010

Network–based resource capital such as political capital, social capital, and reputational capital are critical in providing firms with special access to various resources and legitimacy in emerging markets. However, how these generic nonmarket forms of capital are transformed into value–adding, industry–specific, and firm–specific uses, which subsequently enhance firm competitiveness, remained unanswered. Adopting a dynamic capability approach, this paper posits that corporate entrepreneurship performs a unique role of resource capital configuration and transformation in emerging market firms by continuously renewing firm competences so that congruence with the changing environment can be achieved. Building on this conceptualization, we argue that the positive effects of network–based resource capital on firm performance are channeled through the resource configuration process given by various corporate entrepreneurial activities such as product and organizational innovations as well as new venturing. Empirical evidence of the proposed mediation model is obtained from a survey of established firms in China.
What Drives New Ventures to Internationalize from Emerging to Developed Economies?
Authors: Yamakawa Yasuhiro , Peng Mike W. , Deeds David L.
Published: September 2010

The internationalization of new ventures from emerging economies to developed economies remains an unfilled gap at the intersection of the literature between international entrepreneurship and strategy in emerging economies. What drives some (but not all) new ventures from emerging economies to enter developed economies? We address this question by developing a comprehensive framework based on the three leading perspectives on strategy—industry–based, resource–based, and institution–based views. A series of propositions are proposed to explore the underlying logic behind new ventures’ entrepreneurial entries from emerging to developed economies.
Country of Origin and Foreign IPO Legitimacy: Understanding the Role of Geographic Scope and Insider Ownership
Authors: Bell R. Greg , Moore Curt B. , Al–Shammari Hussam A.
Published: September 2010

Foreign firms from emergent economies are increasingly seeking equity capital in developed economies like the United States. Utilizing institutional, signaling, and agency theories this research examines the legitimacy of foreign IPOs (initial public offerings) in the United States. Employing the population of foreign IPOs listed on U.S. stock exchanges between 1997 and 2004, it is demonstrated that firms from countries with governmental policies and institutional practices that protect the economic freedom of its citizens are significantly less underpriced than IPOs of firms originating from countries experiencing lower levels of economic freedom. The evidence further indicates that firms from emerging economies can overcome negative country perceptions associated with lower levels of legitimacy by increasing their international scope of operations prior to beginning the IPO process as well as by retaining acceptable levels of ownership in their respective firms.
Commentary: What Were They Thinking? The Role of Family Firm Mental Models on Threat Recognition
Authors: Kellermanns Franz W. , Barnett Tim
Published: September 2010

In this commentary, we extend Sirmon, Arregle, Hitt, and Webb's work in this issue by introducing shared mental models as antecedents of threat of imitability recognition and as moderators of the relationship between threat recognition and strategic action. Specifically, while Sirmon, Arregle, Hitt, and Webb focus on responses to threat recognition, we develop propositions on how shared mental models related to business issues affect the threat recognition process and on how shared mental models related to family issues influence strategic responses to recognized threats. Implications and areas for future research are discussed.
Commentary: The Prequel to Family Firm Culture and Stewardship: The Leadership Perspective of the Founder
Authors: Eddleston Kimberly A.
Published: September 2010

This commentary considers the role of the founder in establishing a family firm's culture. Drawing from transformational leadership theory, it is argued that a founder who displays transformational leadership behaviors may be more likely to establish a family firm culture that reflects family commitment, stewardship, and strategic flexibility. As such, this commentary extends the article by Zahra, Hayton, Neubaum, Dibrell, and Craig by linking stewardship theory with transformational leadership theory, and viewing family firm culture as an intervening mechanism between leadership behaviors and strategic flexibility.
Commentary and Extension: Moderating the Outcome of Identity Confirmation in Family Firms
Authors: Klein Sabine B.
Published: September 2010

In this commentary, I provide suggestions for further refining the way we view and apply the identity confirmation concept to family businesses. I distinguish different family types, such as the core family, the extended family, the patchwork family, and the multigenerational kinship family. In addition, I concentrate on crucial life cycle points in the sense that a business family stays and works together usually much longer than any other work–related group. From a dynamic perspective, certain opportunities and risks in applying the identity confirmation concept become obvious for families in family businesses. Different moderating variables might distinguish whether identity confirmation results in positive or negative outcomes. These moderators point to important future research projects in the area of family business.
Examining the Link between “Familiness” and Performance: Can the F–PEC Untangle the Family Business Theory Jungle?
Authors: Rutherford Matthew W. , Kuratko Donald F. , Holt Daniel T.
Published: September 2010

Family business research appears to be caught in a “jungle” of competing theories in regards to familiness and performance. This study provides a further empirical examination into that relationship. We employ a family influence scale (the familiness–power, experience, and culture scale [F–PEC]) presented by Klein, Astrachan, and Smyrnios in an attempt to assess the relationship between familiness and performance in 831 family businesses. The resulting regression analysis adds to the current state of the literature by demonstrating significant and interesting results. Specifically, familiness showed associations with revenue, capital structure, growth, and perceived performance; however, the relationships were both positive and negative, thus casting doubt upon the F–PEC as a vehicle for untangling the jungle. We conclude with discussion and implications.
Practitioner Commentary: Moving from Theory to Practice in Family Business Research
Authors: Vought Kimber L. , Baker LaKami T. , Smith Garry D.
Published: September 2010

This paper examines the papers presented at the 2007 Theories of Family Enterprise Conference for their applicability to practice and presents some ideas to make family business research more appropriate to practitioners. In general, we found the papers are not immediately useful to practitioners; however, the papers of a theory conference should not necessarily be immediately useful to practitioners. We identify several areas for future research, which include the development of a concrete definition for family business, a thorough analysis of the positive and negative effects of the concept of familiness, a close look at failed family business, as well as other issues.
How Does Valvular Regurgitation Alter Left Ventricular Function as Demonstrated by Noninvasive Techniques? Comparisons with Invasive Hemodynamic Studies
Authors: SCHROEDER E. , MARCHANDISE B. , KREMER R.
Published: September 2010

This article reviews the effects of acute and chronic valvular regurgitation on the function of the left ventricle. The article reviews methods and problems in the quantitation of valvular regurgitation, the assessment of left ventricular dimension and ejection fraction, and predictors of surgical outcome. This frequent and important clinical problem can be well addressed by echocardiography. (ECHOCARDIOGRAPHY, Volume 8, January 1991)
Experimental Observations on Intracavitary Imaging of Cardiac Structures with 20‐MHz Ultrasound Catheters
Authors: PANDIAN NATESA G. , SCHWARTZ STEVEN L. , HSU TSUI L. , WEINTRAUB ANDREW R. , KATZ SARAH E. , ARONOVITZ MARK , KONSTAM MARVIN A. , SALEM DEEB N. , KREIS ANDREAS
Published: September 2010

Recently catheter‐based ultrasound devices have become available for obtaining high‐resolution images of blood vessels. In this study we evaluated the feasibility of imaging cardiac structures using 20‐MHz ultrasound catheters. In 25 dogs, the ultrasound catheter was advanced into the right and left heart chambers percutaneously. The intravascular devices yielded images of the right atrial wall, right and left ventricular myocardia, tricuspid, pulmonic, and aortic valves, and the great vessels. Although the small depth of field inherent to the frequency range of 20 MHz limited the visualization to only portions of the cardiac chambers, the images obtained were of high resolution and allowed easy identification of the various cardiac structures. Intracardiac echocardiography was easy to perform and did not result in damage to the cardiac structures. We conclude that intracardiac echocardiography using ultrasound catheters provides a new approach to cardiac imaging and that the development of lower frequency catheters could aid in extending the potential utility of intracardiac echocardiography. (ECHOCARDIOGRAPHY, Volume 8, January 1991)