Projects - Center for Urban and Regional Analysis

Research		Current Porjects
Support Opportunities		Current Porjects
Awards		Current Projects / Past Projects
Roundtables		CURA Research Projects
Publications		Path Reduction for Network Interdiction Model Identify vulnerability in network infrastructure is necessary in planning for enhanced network security. Network infrastructure models are one approach for identifying such vulnerabilities. Many modeling approaches are often premised an identifying all paths of movement between network origins to destinations. However given the complexities associated to the real world networks, identifying all possible O-D paths is not generally possible. Thus, we propose a new model formation which can reduce the number of paths of the network and hence, the complexity associated with searching for network vulnerabilities.
Presentations
Current Projects
Survey Research
Urban Disciplines
		Evaluating Radar Systems: Backup Coverage and Spatial Representation Weather radar is a vital tool in forecasting and disseminating warnings to people at risk of impending inclement weather. The National Weather Service (NWS) has been investigating the implementation of phased array radar technology to improve the performance of weather radar. With costs in the millions of dollars, it behooves planners to assess facility placement in a manner the maximizes coverage of the population, establishes survivability (or redundance) of coverage, and minimizes costs. In this effort we have built upon the Backup Coverage Location Problem (Hogan and Revelle, 1986) to account for complementary partial coverage of an area by multiple radar. Our results show that implementation of this model assesses coverage in a more realistic manner, and suggests radar facility locations which provide coverage and backup coverage to a greater population than both other model formulation results and the current NWS radar locations.
		Placement of Potential Facilities on Continuous Road Networks An issue of facility placement arises in that how facility locations are selected along continuous space. In this research, how public transport stop locations can be placed along continuous road network will be discussed. Many studies have involved to bus stop placements or designs (Wirasingheand Ghoneim1981, Demetskyand Lin 1982, Federal Transit Administration 1996, Furth and Rahbee2000, Saka2001) but methodologies developing stop placements along continuous road network maximizing given demand have not been discussed. Facility placement in continuous space has been a major concern since Weber’s (1909) single sitingproblem in pursuit of minimal transportation costs. This simple but leading work has been followed by various spatial optimization problems locating facilities in continuous space to maximize or minimize its objectives. Church (1994) and Murray and Tong (2007) suggested planar versions of Maximal Covering Location Problem (MCLP), called Planar Maximal Covering Problem (PMC) and Extended Planar Maximal Covering Location Problem-Euclidean (EPMCE) respectively. Both approaches relax the requirement of discrete locations of facility by allowing facilities to be located across continuous space. While PMC maximizes coverage for the point-based demand, EPMCE maximizes coverage for various types of demand objects, such as not only points but also lines and polygons. EPMCE is very useful to provide unbiased and complete coverage for demand objects of lines and polygons without any point representation that possibly misleads the actual coverage. Based on property of EPMCE (Murray and Tong 2007), this research develops such a model as maximizes coverage for polygon-based demand objects when potential facility are to be distributed along road networks. The following figures show thathow those road network are discretizedbased on polygon-based demand obejcts.
		Connectivity Change in Habitat Networks Habitat management is essential for safeguarding important flora and fauna. Further, habitat connectivity is a crucial component for maintaining biodiversity given that it is known to have implications for species persistence. However, damage to habitat due to natural and human induced hazards can alter spatial relationships between habitats, potentially impacting biodiversity. Therefore, the susceptibility of spatial relationships to patch loss and associated connectivity degradation is obviously an important factor in maintaining existing or planned biodiversity networks. Identifying patches vital to connectivity is critical both for effectively prioritizing protection (e.g., enhancing habitat connectivity) and establishing disaster mitigation measures (e.g., stemming the spread of habitat loss). This focus of this project is on developing methodologies for characterizing connectivity change associated with habitat systems. The ultimate goal of this research is to better understand how habitat connectivity can be impacted by site loss, to better inform biodiversity management planning. In particular, work has involved the development of new measurements of landscape connectivity as well as approaches for assessing the distributional aspects of connectivity given the loss of habitat sites.
		p-hub Protection Models for Reliable Hub and Spoke Network Design In this project, we develop a new hub location problem named as the ‘p-hub protection models (PHPRO)’ as an approach of survivable network design in telecommunications. The main goal of the PHPRO models is to build a network which minimizes the total potential loss of flows in the face of network failure. As a protective scheme, the model considers *back-up disjoint routes* for interacting flows between OD pairs.
		Efficient Identification of Geographic Restrictions in Location Modeling Using GIS Spatial separation in located services and activities is often essential. Examples include homeland security, military asset defense, impacts on the environment, franchise outlet location, and promoting public wellbeing. When planning and management is supported by mathematical modeling, a difficulty has been efficient representation of spatial separation requirements. This paper reviews an optimization model, the anti-covering location problem, used to support planning and management problems where spatial separation must be ensured between sited services/activities. An approach is presented for the efficient and effective identification and use of spatial separation conditions in this model based upon the use of a geographic information system (GIS). Results highlight the significance of the developed methodology in terms of computational requirements, tractability and effectiveness. This research enhances capabilities for addressing important practical planning problems.