An agent-based retail location model on a supply chain network

Clusters of business locations, which considerably impact daily activities, have been prominent phenomena. Yet the question of how and why Þrms cluster in certain areas has not been sufficiently studied. This paper investigates the emergence of clusters of business locations on a supply chain network comprised of suppliers, retailers, and, consumers. Krugman (1996) argued that urban concentration involved a tension between the centripetal and the centrifugal forces. Based on that notion, this research proposes an agent-based model of retailers' location choice in a market of homogeneous products. In this game, retailers endeavor to maximize their proÞts by changing locations. Retailers' distribution patterns are measured by entropy and cluster density. Simulation results reveal that as more retailers engage in the game, clusters autonomously emerge and the entropy of clusters increases. Once retailers exceed a certain number, average density of clusters begins to decline; all discrete clusters gradually merge to a large cluster, spreading out uniformly. This research thus Þnds that the centripetal force attracts retailers to supplier locations; with even more retailers entering the market, the centrifugal force disperses them. The sensitivity results on model parameters and consumers' demand elasticity are also discussed.clustering, supply chain network, location choice, distribution pattern

Modeling phase changes of road networks

Adopting an agent-based approach, this paper explores the topological evolution of road networks from a microscopic perspective. We assume a decentralized decision-making mechanism where roads are built by self-interested land parcel owners. By building roads, parcel owners hope to increase their parcelsÕ accessibility and economic value. The simulation model is performed on a grid-like land use layer with a downtown in the center, whose structure is similar to the early form of many Midwestern and Western (US) cities. The topological attributes for the networks are evaluated by multiple centrality measures such as degree centrality, closeness centrality, and betweenness centrality. Our findings disclose that the growth of road network experiences an evolutionary process where tree-like structure first emerges around the centered parcel before the network pushes outward to the periphery. In addition, road network topology undergoes obvious phase changes as the economic values of parcels vary. The results demonstrate that even without a centralized authority, road networks have the property of self-organization and evolution; furthermore, the rise-and-fall of places in terms of their economic/social values may considerably impact road network topology.road network, land parcel, network evolution, network growth, phase change

Modeling Minneapolis Skyway Network

Adopting an agent-based approach, this paper explores the topological evolution of the Minneapolis Skyway System from a microscopic perspective. Under a decentralized decision-making mechanism, skyway segments are built by self-interested building owners. We measure the accessibility for the blocks from 1962 to 2002 using the size of office space in each block as an indicator of business opportunities. By building skyway segments, building owners desire to increase their buildingsÕ value of accessibility, and thus potential business revenue. The skyway network in equilibrium generated from the agent model displays similarity to the actual skyway system. The network topology is evaluated by multiple centrality measures (e.g., degree centrality, closeness centrality, and betweenness centrality) and a measure of road contiguity, roadness. Sensitivity tests such parameters as distance decay parameter and construction cost per unit length of segments are performed. Our results disclose that the accessibility- based agent model can provide unique insights for the dynamics of the skyway network growth.skyway network, network growth, agent-based modeling

The Effects of Daylight Saving Time on Vehicle Crashes in Minnesota

Daylight saving time (DST), implemented as an energy saving policy, impacts many other aspects of life; one is road safety. Based on vehicle crash data in Minnesota from 2001 to 2007, this paper evaluates long- and short-term effects of DST on daily vehicle crashes. To provide evidence to explain the causes of more/fewer crashes in DST, we examine the impact of DST on crashes in four periods of a day: 3 am-9 am, 9 am-3 pm, 3 pm-9 pm, 9 pm-12 pm. The effects of risk and exposure to traffic are also separated. Our statistical models not only include weather conditions and dummy variables for days in DST as independent variables, but also consider traffic volumes on major roads in different periods of a day. Our major finding is that the short-term effect of DST on crashes on the morning of the first DST is not statistically significant. Moreover, it is interesting to notice that while DST per se is associated with fewer crashes during dusk, this is in part offset because it is also associated with more traffic on roads (and hence more crashes). Our path analysis shows that overall DST reduces crashes.daylight saving time, vehicle crashes, exposure, fatal crashes, traffic volume, Minnesota

A Positive Theory of Network Connectivity

This paper develops a positive theory of network connectivity, seeking to explain the micro-foundations of alternative network topologies as the result of self-interested actors. By building roads, landowners hope to increase their parcelsÕ accessibility and economic value. A simulation model is performed on a grid-like land use layer with a downtown in the center, whose structure resembles the early form of many Midwest- ern and Western (US) cities. The topological attributes for the networks are evaluated. This research posits that road networks experience an evolutionary process where a tree-like structure first emerges around the centered parcel before the network pushes outward to the periphery. In addition, road network topology undergoes clear phase changes as the economic values of parcels vary. The results demonstrate that even without a centralized authority, road networks have the property of self-organization and evolution, and, that in the absence of intervention, the tree-like or web-like nature of networks is a result of the underlying economics.road network, land parcel, network evolution, network growth, phase change, centrality measures, degree centrality, closeness centrality, betweenness centrality, network structure, treeness, circuitness, topology

An Agent-based Model of Retail Location with Complementary Goods

This paper examines the emergence of retail clusters on a supply chain network comprised of suppliers, retailers, and consumers. An agent-based model is proposed to investigate retail location distribution in a market of two complementary goods. The methodology controls for supplier locales and unit sales prices of retailers and suppliers; a consumer's willingness to patronize a retailer depends on the total travel distance of buying both goods. On a circle comprised of discrete locations, retailers play a non-cooperative game of location choice to maximize individual proÞts. Our Þndings suggest that the number of clusters in equilibrium follow a power-law distribution and that hierarchical distribution patterns are much more likely to occur than the spread-out ones. In addition, retailers of complementary goods tend to co-locate at supplier locales. Sensitivity tests on the number of retailers and retailers' sequence of moving are also performed.clustering, agent-based model, location choice, power-law distribution pattern, retailing

Microstrip Yagi array for MSAT vehicle antenna application

A microstrip Yagi array was developed for the MSAT system as a low-cost mechanically steered medium-gain vehicle antenna. Because its parasitic reflector and director patches are not connected to any of the RF power distributing circuit, while still contributing to achieve the MSAT required directional beam, the antenna becomes a very efficient radiating system. With the complete monopulse beamforming circuit etched on a thin stripline board, the planar microstrip Yagi array is capable of achieving a very low profile. A theoretical model using the Method of Moments was developed to facilitate the ease of design and understanding of this antenna

Preparing the Hospitality and Tourism Workforce for the Future of Work

The economic restructuring necessitated by the Covid-19 pandemic has ignited a fundamental transformation of the US workforce driven by powerful digital technologies. No sector has been hit harder than the hospitality and tourism industry (H&T), and no industry has more to gain from reinvention. H&T employs about 32% of the US labor force; however, workers’ wages, benefits, and career support are among the lowest of all industries. Moreover, research shows that numerous jobs in H&T are susceptible to automation due to advancements in artificial intelligence (AI). The fears related to job loss resulting from applying advanced technology, such as AI, are rising, and the H&T workforce requires significantly higher levels of research support to advance the workers’ skills and careers

How Hurricanes Impact Florida\u27s Tourism Industry

Almost every year, hurricanes bear down upon the state of Florida. The storms appear to be growing in occurrence and severity. While the media cover the damage and death toll, the impacts on the state\u27s critical tourism sector remain largely anecdotal. The full story lies buried in data. Dr. Arthur Huang from UCF\u27s Rosen College of Hospitality Management has investigated different data sets to understand the impact of hurricanes on the tourism industry. What has been uncovered has significance not only for Florida but for tourism sectors elsewhere affected by these giant storms