The traveling–salesman problem (TSP) is one of the most studied problems in combinatorial optimization [16, 14]. The TSP is simply stated, has practical applications, and is a representative of a large class of important scientific and engineering problems. The TSP can be viewed as a graph–theory problem if the cities are identified with the vertices of a graph, and the links between the cities...

The authors examined whether absolute and relative judgments about global-scale locations and distances were generated from common representations. At the end of a 10-week class on the regional geography of the United States, participants estimated the latitudes of 16 North American cities and all possible pairwise distances between them. Although participants were relative experts, their latit...

I assess the magnitude of human capital spillovers by estimating production functions using a unique firm-worker matched data set. Productivity of plants in cities that experience large increases in the share of college graduates rises more than the productivity of similar plants in cities that experience small increases in the share of college graduates. These productivity gains are offset by ...

In the real world, cities exist because of external economies associated with the geographic concentration of firms within a city. Of course, such a geographic proximity with input providers and consumers, would at first reduce transportation costs. But why cities, information cities, i.e. large agglomerations of people and economic activity emerge in the virtual world? In the Internet, transpo...

The advent of geographic online social networks such as Foursquare, where users voluntarily signal their current location, opens the door to powerful studies on human movement. In particular the fine granularity of the location data, with GPS accuracy down to 10 meters, and the worldwide scale of Foursquare adoption are unprecedented. In this paper we study urban mobility patterns of people in ...

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2014 We study the travelling salesman problem on dilute lattices where the cities are represented by random lattice sites, occupied with concentration p, and the salesman intends to visit a finite fraction f of the total number of cities. The variation of the average optimal travel distance per city L (p, f) against f are investigated here for various values of p. The values of the normalised t...

We reexamine the evidence for “border effects” in deviations from the law of one price, using data for consumer prices from Canadian and U.S. cities. The study parallels Engel and Rogers (1996), except that this study uses actual price data rather than price index data. We find evidence of border effects both in the levels of prices and the percentage change in prices. Even accounting for dista...

China has been undergoing a remarkably rapid urbanization process in the last several decades. Urbanization is a complicated phenomenon involving imbalanced transformation processes, such as population migrations, economic advancements and human activity dynamics. It is important to evaluate the imbalances between transformation processes to support policy making in the realms of environmental ...

This paper examines the spatial structures of commercial real estate buildings (Offices, Retails) in four Chinese cities: Beijing, Shanghai, Shenzhen, and Guangzhou. In contrast to previous studies, this paper focused on the changes of the spatial pattern by involving the time variables to categorize the buildings into 3 time periods (Before 1995, 1996-2005, and 2006-2015). The research questio...