A Spatial Search-Location Model of Retail Centers

Central place theory can be modeled using two types of optimization problems. Location-allocation models have been widely applied to operationalize central place theory as an aggregate optimization problem. This paper constructs a spatial search-location model to formulate central place theory as an individual optimization problem.     

Agglomeration Diseconomies of Traffic Congestion and Agglomeration Economies of Interaction in the Information-Oriented City

This paper presents a partial equilibrium model of land, labor, and transportation markets in an information-oriented city with traffic congestion of commuting and agglomeration economies of interaction. We derive the equilibria by numerical computations using specific utility, production, and congestion functions. The laissez-faire equilibrium is compared with the optimum. In contrast with the results of many previous papers, at the optimum the CBD becomes compact and the city more suburbanized than the laissez-faire equilibrium. We also analyze the effects of a Pigouvian tax system and subsidies on the spatial structure in the city.     

Relative Variability in Streetscape Skeletons and Spatial Association: Application for Identifying Harmonious and Inharmonious Streetscape Skeletons in Tokyo

Whether or not a streetscape skeleton (defined as the 3D street space) is harmonious depends on the degree of difference between heights and setbacks of adjacent buildings, which is called the relative variability in the streetscape skeleton, but this has generally been overlooked. Because streetscape skeletons are ambiguous, evaluating whether or not they are harmonious is thus conceptually and technically challenging. This article, therefore, considers the relative variability in streetscape skeletons and their spatial associations and answers the following question: where are harmonious or inharmonious streetscape skeletons locally clustered? The relative variability in the streetscape skeletons in the districts of the Tokyo metropolitan region was computed, where building heights and setbacks are directly controlled through streetscape promotion district planning stipulated in the City Planning Act. The spatial association of the relative variability in streetscape skeletons was then visualized to identify where streetscape skeletons are harmonious and inharmonious. The results showed that although harmonious streetscape skeletons are spatially clustered inside the domain bounded by wider streets, such clusters are small and spatially scattered. We, therefore, concluded that the effectiveness of direct controls through streetscape-promoting district planning to maintain and create harmonious streetscape skeletons is spatially limited and thus insufficient.     

Cave occupations in Southeastern Arabia in the second millennium BCE: Excavation at Mugharat al-Kahf,North-Central Oman

This paper reports the results of excavation at Mugharat al-Kahf (WTN01) in Wādī Tanūf, North-central Oman. It also provides information on the nonmortuary and nonsedentary activities in central Oman during the Wādī Sūq period (2000–1600 BCE), as the subsistence and social arrangements of this period are the subject of much debate. Previous surveys had discovered a substantial amount of Wādī Sūq pottery at the site. This project took forward the excavation for further exploration. The excavation at Test Pit 1 identified Layers Ia and Ib, wherein pottery sherds, charred date stones and other samples for radiocarbon dating were discovered. These prove the cave's occupation during the early third millennium BCE, early second millennium BCE and the Islamic period. The analysis of artefacts and floral remains provided insights into the sojourn, storage and consumption of dates in the cave, and the mobile lifestyle in central Oman.     

GENERAL EQUILIBRIUM ANALYSIS OF URBAN SPATIAL STRUCTURE. THE PORT-CITY MODEL RECONSIDERED*

In this paper, I consider a general equilibrium urban spatial structure in the setting of a port city by adopting Cobb-Douglas type functional forms for production and utility functions. Unlike previous port-city models, this one can generate four land-use patterns, that is, (1) monocentric, (2) completely integrated, (3) partially integrated (with integration at the center), and (4) partially integrated (with integration at the urban fringe) land-use patterns, and the last pattern suggests a new explanation of suburbanization of employment. The existence and uniqueness of each land-use pattern is proven in a simple constructive way.     

AN ANALYSIS OF TWO-CENTER COMPETITION

This paper analyzes the competition between the two centers which belong to different hierarchical levels. A two-center competition model is constructed by applying the Lotka-Volterra equations. This model includes as parameters the scale economies of central places, the consumer's outflow from the region, as well the distance between centers. As it is assumed in this model that the carrying capacity of the region will be affected by the consumer's outflow rate from it, the outflow rate is estimated by a demand generation model and then incorporated into the two-center competition model.