Dealing with Timing and Synchronization in Opportunities for Joint Activity Participation. 公共活动参与机会中实时性与同步性处理

The ability of people to access opportunities offered by the built environment is circumscribed by various sets of space–time constraints, including the requirements to meet other persons at particular times and places to undertake activities together. While models of space–time accessibility recognize that joint activities may constrain the performance of activities in space and time, their specifications do not explicitly acknowledge the opportunities that individuals of a group have for joint activity participation. Therefore, this article focuses on joint activity participation and argues that collective activity decisions are the outcome of a complex process involving various aspects of timing, synchronization, and social hierarchy. The utility‐theoretic model proposed here quantifies the extent to which opportunities can be jointly accessed by a particular group of people within a specific time period. Central to the approach are three key variables: the attractiveness of an opportunity, the time available for activity participation, and the travel time to an activity location. Because of the multiperson character of joint activities, the determination of these variables is subject to individual preferences, privileges, and power differentials within a group. Specific attention is given to how time‐of‐day and synchronization effects influence the opportunities accessible to a group of individuals. The impact of these factors on joint accessibility is illustrated by a real‐world example of an everyday rendezvous scenario. The outcomes of a simulation exercise suggest that time‐of‐day and synchronization effects significantly affect the benefits that can be gained from opportunities for joint activities.     

An Empirically Based Implementation and Evaluation of a Hierarchical Model for Commuting Flows. 一种基于经验的层状通勤流模型实现与评估

This article provides an empirical evaluation of a hierarchical approach to modeling commuting flows. As the gravity family of spatial interaction models represents a benchmark for empirical evaluation, we begin by reviewing basic aspects of these models. The hierarchical modeling framework is the same that Thorsen, Ubøe, and Nævdal (1999) used. However, because some modifications are required to construct a more workable model, we undertake a relatively detailed presentation of the model, rather than merely referring to the presentation in Thorsen, Ubøe, and Nævdal (1999) . The model uses a hierarchical specification of a transportation network and the individual search procedure. Journeys to work are determined by the effects of distance deterrence and of intervening opportunities, and by the location of potential destinations relative to alternatives at subsequent levels in a transportation network. The model calibration uses commuting data from a region in western Norway. The estimated parameter values are reasonable, and the explanatory power is very satisfactory when compared with the results of a competing destinations approach.     

The notion τὸ πέρας τῆς ἀνακομιδῆς and the location of Ptolemais of the Hunts in the Periplus of the Erythraean Sea

The Periplus of the Erythraean Sea describes the route of a trade ship in the ancient Erythraean Sea following certain reference points. One of these was called τ? π?ρα? τ?? ?νακομιδ??, from which the distance to Ptolemais of the Hunts was given. It was generally understood as the ‘endpoint of return’ and thought to be Berenice. In fact, the phrase is to be understood as ‘the endpoint of sailing/delivery from (Egypt)’ and the place appears to be identifiable with modern Anfile Bay, where the trade ships turned back. The port itself had to be visited on the way back to Egypt. The reason was connected with the primary goal of the establishment of the port: it was much more practical to take elephants aboard on the way back to Egypt. The information on Ptolemais of the Hunts seems to derive from a late Ptolemaic source. The exact route of the ship, referred to by the author of the Periplus, is unknown and even knowledge of the exact distance from the reference point does not allow us to identify a region, where Ptolemais of the Hunts is to be sought.     

Determinants of Variation in Population–Employment Interaction Findings: A Quasi‐Experimental Meta‐Analysis. 人口‐就业相互作用的决定因素研究：一种准实验元分析法

This article reports about a metaregression analysis of empirical results generated using data for the northern Netherlands (1988–2002) in order to investigate the ambiguity in results in the population–employment interaction literature. Specifically, the analysis deals with the issue whether “jobs follow people” or “people follow jobs.” The article starts with introducing the basics of quasi‐experimental meta‐analysis and with identifying some advantages of using quasi‐experimental meta‐analysis as compared with the standard meta‐analysis approach. Two subsequent sections document the selection of the population–employment interaction model and salient characteristics of the data set as well as the setup of the primary analyses. A total of 4,050 quasi‐experimental empirical results for the jobs–people direction of causality are generated using different specifications and estimators for a spatial econometric interaction model. The subsequent metaregression analysis reveals that the empirical results are largely shaped by the spatial, temporal, and employment characteristics of the data sampling. The results also appear much more sensitive to different measurements of the model's key variables when compared with alternative specifications of the spatial weights matrix. The main determinant driving empirical results about jobs–people causality are differences in model specification and estimation, as revealed by an inherent bias in parameter estimates and misguided inferences for some of the commonly used specifications. Finally, suggestions for future research are identified.     

The Colocation Quotient: A New Measure of Spatial Association Between Categorical Subsets of Points. 协同区位商：点集分类子集间空间关联性的新度量标准

This article presents a new metric we label the colocation quotient (CLQ), a measurement designed to quantify (potentially asymmetrical) spatial association between categories of a population that may itself exhibit spatial autocorrelation. We begin by explaining why most metrics of categorical spatial association are inadequate for many common situations. Our focus is on where a single categorical data variable is measured at point locations that constitute a population of interest. We then develop our new metric, the CLQ, as a point‐based association metric most similar to the cross‐k‐function and join count statistic. However, it differs from the former in that it is based on distance ranks rather than on raw distances and differs from the latter in that it is asymmetric. After introducing the statistical calculation and underlying rationale, a random labeling technique is described to test for significance. The new metric is applied to economic and ecological point data to demonstrate its broad utility. The method expands upon explanatory powers present in current point‐based colocation statistics.     

A Fractal Approach to Identifying Urban Boundaries. 城市边界识别的分形方法

Fractal geometry can be used for determining the morphological boundaries of metropolitan areas. A two‐step method is proposed here: (1) Minkowski's dilation is applied to detect any multiscale spatial discontinuity and (2) a distance threshold is located on the dilation curve corresponding to a major change in its behavior. We therefore measure the maximum curvature of the dilation curve. The method is tested on theoretical urban patterns and on several European cities to identify their morphological boundaries and to track boundary changes over space and time. Results obtained show that cities characterized by comparable global densities may exhibit different distance thresholds. The less the distances separating buildings differ between an urban agglomeration and its surrounding built landscape, the greater the distance threshold. The fewer the buildings that are connected across scales, the greater the distance threshold.     

A Framework for Exploring Urban Retail Discontinuities. 探索城市零售业不连续性的框架

A key area in the analysis of urban structural evolution is identifying discontinuities. Effective analysis could improve long‐term forecasting and provide a better understanding of how to steer an urban system toward a desirable future state. We use a simple aggregate retail model to demonstrate an algorithm for identifying discontinuities in model parameter space. Explorations of retailing in both Greater London and South Yorkshire in the United Kingdom illustrate how understanding a system's potential for discontinuity can provide insights for both policy makers and retail businesses. The Harris and Wilson model, described in the section so‐named, is used as a simple archetype to illustrate the new framework. This model can be developed in a straightforward way to incorporate further refinement. In “ Executing the model and visualizing the results ,” we describe a single model run and in “ Investigating discontinuities ,” we explain our framework for detecting and analyzing discontinuities. “ Identifying discontinuities in the London retail system ” shows the results of applying this methodology to the Greater London retail system, and in “ Practical applications ,” we explore the policy applications for this technique as related to the decline of town centers in the South Yorkshire retail system. Some concluding comments are offered in “ Conclusions .”     

Aggregation of Regional Economic Time Series with Different Spatial Correlation Structures. 具有不同空间相关结构的区域经济时间序列集成

In this article, we compare the relative efficiency of different forecasting methods of space‐time series when variables are spatially and temporally correlated. We consider two cases: (1) univariate forecasting (i.e., a space‐time series aggregated into a single time series) and (2) the more general instance of multivariate forecasting (i.e., a space‐time series aggregated into a coarser spatial partition). We extend the results in the literature by including the consideration of larger datasets and the treatment of edge effects and of negative spatial correlation. We first introduce a statistical framework based on the space‐time autoregressive class of random field models, which constitutes the basis of our simulation study, and we present the various alternative forecasting methods considered in the simulation. We then present the results of a Monte Carlo study related to univariate forecasting. In order to allow a comparison with the findings of Giacomini and Granger (2004), we consider the same forecasting strategies and the same combinations of the parameter values used there, but with a larger parametric set. Finally, we extend our analysis to the case of multivariate forecasting. The outcomes obtained provide operational suggestions about how to choose between alternative forecasting methods in empirical circumstances.     

Gesundheitspolitik im 19. und frühen 20. Jahrhundert — Deutschland und England als Beispiele —Bericht über eine internationale Arbeitstagung am Zentrum für Interdisziplinäre Forschung der Universität Bielefeld, 7.–9. November 1986

Recent German publications on the social history of health policy stress longterm developments. Especially the preconditions, concepts, and anticipated as well as unexpected consequences must be elaborated more clearly. International comparison seems to be a valid scientific tool for this purpose. An international working group met at the Center for Interdisciplinary Studies/University of Bielefeld for a symposium on “Health Policy in the 19th and early 20th Century — Germany and England as examples”. The general subject was divided in several areas of discussion: social reactions to the cholera; hygienization of every-day-life; imperialism, armed forces and health policy; developments in occupational medicine.     

Wissenschaft — Mathematik — Technik: Ihre Wechselwirkung in der Antike

The question whether there exists an interaction between ‘science’ (foreign text ignored) and ‘technology’ (foreign text ignored, esp. foreign text ignored) in Greek and Roman antiquity is discussed controversially until today. Especially representatives of the philologies strictly deny any form of relation, whereas modern scientists tend to take for granted that the current interaction between (exact) natural sciences and technology has always existed, at least since the beginning of real natural science founded by the ancient Greeks. This paper shows that both parties are right — at least in a certain way. Following current terminology and contents of ‘science’ and ‘technology’ there had been such an interaction — particularly with mathematics as linking element in so far as in antiquity especially foreign text ignored (mechanics) was regarded as applied mathematics and not as science. The strong interaction between pure mathematics and such fields of applied mathematics (namely mechanical technology) based on the fact that technological (mechanical) artefacts were properly constructed mathematically. Some of them are mentioned in this paper (astrolabes and sundials, waterclocks, tools and machines — especially lifting gears, bucket elevators, guns, pneumatic tools —, architecture of temples); in so far the supporters of an interaction between science and technology are right. However, the post-Aristotelian Greeks and Romans did not consider mathematics to be part of ‘science (of nature)’ as the post-kantian exact scientists do. Mathematics to them was a mere ‘art’ — consequently, in the mentioned cases there had been an interaction between ‘arts’ and of course not between ‘science’ and ‘art’ (technology); and in so far those are right who deny an interaction between natural science and technology. This shows that the contrariety of the answers to the question depends on the different terminology chosen. Following the current understanding of ‘exact natural science’ the answer is: yes; following the conception of ‘science’ in the self-understanding of Greek and Roman antiquity the answer is: no — and this is right as well! The reason for this apparent contrariety are just the different meanings and contents of ‘science (of nature)’ in antiquity and modern times.     

Cesare Beccaria's influence on English discussions of punishment, 1764–1789

The impact of Beccaria's On Crimes and Punishments on English discussions of punishment in the twenty-five years following its publication is assessed, with attention being paid to Beccaria's combination of contractarian and early utilitarian thinking. It is argued that Beccaria's influence was particularly striking in England in that he stimulated two disparate strands of reform thinking. The first being exemplified in the work of William Eden, and taking the form of a contractarian, humanitarian version, which owed something to William Blackstone, but was ultimately quite distinct. The second represented in Jeremy Bentham's theory of punishment with its emphasis overwhelmingly on utilitarian calculation.