Results 1 - 10 of 6,387

Geographic Concentration in U.S. Manufacturing Industries: A Dartboard Approach

by Glenn Ellison, Edward L. Glaeser - Journal of Political Economy
"... This paper discusses the prevalence of Silicon Valley–style localiza-tions of individual manufacturing industries in the United States. A model in which localized industry-specific spillovers, natural ad-vantages, and pure random chance all contribute to geographic concentration is used to develop a ..."
Abstract - Cited by 599 (16 self) - Add to MetaCart
localized. In many industries, however, the degree of localization is slight. We explore the nature of agglomerative forces in describing patterns of concentration, the geographic scope of localization, and the coagglomeration of related industries and of industries with strong upstream-downstream ties.

Geography-informed Energy Conservation for Ad Hoc Routing

by Ya Xu, John Heidemann, Deborah Estrin - ACM MOBICOM , 2001
"... We introduce a geographical adaptive fidelity (GAF) algorithm that reduces energy consumption in ad hoc wireless networks. GAF conserves energy by identifying nodes that are equivalent from a routing perspective and then turning off unnecessary nodes, keeping a constant level of routing fidelity. GA ..."
Abstract - Cited by 1045 (21 self) - Add to MetaCart
We introduce a geographical adaptive fidelity (GAF) algorithm that reduces energy consumption in ad hoc wireless networks. GAF conserves energy by identifying nodes that are equivalent from a routing perspective and then turning off unnecessary nodes, keeping a constant level of routing fidelity

Reversal of fortune: geography and institutions in the making of modern world income,Quarterly

by Daron Acemoglu , Simon Johnson , James A Robinson - Journal of Economics, , 2002
"... Among countries colonized by European powers during the past 500 years, those that were relatively rich in 1500 are now relatively poor. We document this reversal using data on urbanization patterns and population density, which, we argue, proxy for economic prosperity. This reversal weighs against ..."
Abstract - Cited by 450 (31 self) - Add to MetaCart
Among countries colonized by European powers during the past 500 years, those that were relatively rich in 1500 are now relatively poor. We document this reversal using data on urbanization patterns and population density, which, we argue, proxy for economic prosperity. This reversal weighs

The Geography of Innovation

by Maryann P. Feldman , 1994
"... This research examines spatial patterns of manufacturing product innovation and provides a model of factors contributing to geographic concentration of innovation. The model maintains that innovation is related to concentrations of innovative inputs, including: university R&D, industrial R&D ..."
Abstract - Cited by 310 (15 self) - Add to MetaCart
This research examines spatial patterns of manufacturing product innovation and provides a model of factors contributing to geographic concentration of innovation. The model maintains that innovation is related to concentrations of innovative inputs, including: university R&D, industrial R

Syndication networks and the spatial distribution of venture capital investments

by Olav Sorenson, Toby E. Stuart - American Journal of Sociology , 2001
"... Sociological investigations of economic exchange reveal how institutions and social structures shape transaction patterns among economic actors. This article explores how interfirm networks in the U.S. venture capital (VC) market affect spatial patterns of exchange. Evidence suggests that informatio ..."
Abstract - Cited by 235 (11 self) - Add to MetaCart
Sociological investigations of economic exchange reveal how institutions and social structures shape transaction patterns among economic actors. This article explores how interfirm networks in the U.S. venture capital (VC) market affect spatial patterns of exchange. Evidence suggests

Friendship and Mobility: User Movement In Location-Based Social Networks

by Eunjoon Cho, Seth A. Myers, Jure Leskovec
"... Even though human movement and mobility patterns have a high degree of freedom and variation, they also exhibit structural patterns due to geographic and social constraints. Using cell phone location data, as well as data from two online location-based social networks, we aim to understand what basi ..."
Abstract - Cited by 237 (0 self) - Add to MetaCart
Even though human movement and mobility patterns have a high degree of freedom and variation, they also exhibit structural patterns due to geographic and social constraints. Using cell phone location data, as well as data from two online location-based social networks, we aim to understand what

The Atlantic multidecadal oscillation and its relationship to rainfall and river flows in the continental

by David B. Enfield, Alberto M. Mestas-nufiez, Paul J. Trimble , 2001
"... Abstract. North Atlantic sea surface temperatures for 1856-1999 contain a 65-80 year cycle with a 0.4 øC range, referred to as the Atlantic Multidecadal Oscillation (AMO) by Kerr [2000]. AMO warm phases occurred during 1860-1880 and 1940-1960, and cool phases during 1905-1925 and 1970-1990. The sign ..."
Abstract - Cited by 231 (4 self) - Add to MetaCart
and 1950s. Between AMO warm and cool phases, Mississippi River outflow varies by 10 % while the inflow to Lake Okeechobee, Florida varies by 40%. The geographical pattern of variability is influenced mainly by changes in summer rainfall. The winter patterns of interannual rainfall variability associated

A Few Chirps About Twitter

by Balachander Krishnamurthy, Phillipa Gill, Martin Arlitt
"... Web 2.0 has brought about several new applications that have enabled arbitrary subsets of users to communicate with each other on a social basis. Such communication increasingly happens not just on Facebook and MySpace but on several smaller network applications such as Twitter and Dodgeball. We pre ..."
Abstract - Cited by 215 (5 self) - Add to MetaCart
timeline. We identify distinct classes of Twitter users and their behaviors, geographic growth patterns and current size of the network, and compare crawl results obtained under rate limiting constraints. Categories and Subject Descriptors C.4 [Performance of Systems]: [Measurement techniques, Modeling

INSTITUTIONS DON’T RULE: DIRECT EFFECTS OF GEOGRAPHY ON PER CAPITA INCOME

by Jeffrey D. Sachs , 2003
"... In a series of papers, my colleagues and I have demonstrated that levels of per capita income, economic growth, and other economic and demographic dimensions are strongly correlated with geographical and ecological variables such as climate zone, disease ecology, and distance from the coast. Three r ..."
Abstract - Cited by 212 (2 self) - Add to MetaCart
In a series of papers, my colleagues and I have demonstrated that levels of per capita income, economic growth, and other economic and demographic dimensions are strongly correlated with geographical and ecological variables such as climate zone, disease ecology, and distance from the coast. Three

Discovery of spatial association rules in geographic information databases

by Krzysztof Koperski, Jiawei Han , 1995
"... Abstract. Spatial data mining, i.e., discovery of interesting, implicit knowledge in spatial databases, is an important task for understanding and use of spatial data- and knowledge-bases. In this paper, an e cient method for mining strong spatial association rules in geographic information database ..."
Abstract - Cited by 212 (14 self) - Add to MetaCart
Abstract. Spatial data mining, i.e., discovery of interesting, implicit knowledge in spatial databases, is an important task for understanding and use of spatial data- and knowledge-bases. In this paper, an e cient method for mining strong spatial association rules in geographic information
Results 1 - 10 of 6,387