The Anti-Covering Location Problem: new modeling perspectives and solution approaches

Dispersive strategies and outcomes are readily apparent in many geographic contexts. In particular, dispersive strategies can be seen in activities such as: the scattering of military missile silos and ammunition bunkers, center-pivot crop irrigation systems, location of parks, franchise store location, and territorial species den/nest locations. Spatial optimization models represent dispersion where selected facility locations are maximally "packed" or maximally "separated." The Anti-Covering Location Problem, in particular, is one in which a maximum number of facilities are located within a region such that each facility is separated by at least a minimum distance standard from all others. In this context, facilities are "dispersed" from each other through the use of the minimum separation standard. Solutions to this problem are called maximally "packed" as there exists no opportunity to add facilities without violating minimum separation standards. The Anti-Covering Location Problem (ACLP) can be defined on a continuous space domain, or more commonly, using a finite set of discrete locations. In this dissertation, it is assumed that there exists a discrete set of sites, among which a number will be selected for facility locations, and that this general problem may represent a number of different problems ranging from habitat analysis to public policy analysis. The main objective of this dissertation is to propose a new and improved optimization model for the ACLP when applied to a discrete set of points on a Cartesian plane using a combination of separation conditions called core-and-wedge constraints. This model structure, by its very definition, demonstrates that all planar problems can be defined using at most seven clique constraints for each site. In addition, the use of an added set of facet constraints in reducing computational effort is explored. Anti-covering location model solutions are maximally packed, providing an "optimistic" estimate of what may be possible in dispersing facilities. But, what if less than optimal sites are employed in a dispersive pattern. That is, to what extent can an optimal maximally packed configuration be disrupted? This possibility is explored through the development of a new model, called the Disruptive Anti-Covering location model

Experimental study of visual corona under aeronautic pressure conditions using low-cost imaging sensors

Visual corona tests have been broadly applied for identifying the critical corona points of diverse high-voltage devices, although other approaches based on partial discharge or radio interference voltage measurements are also widely applied to detect corona activity. Nevertheless, these two techniques must be applied in screened laboratories, which are scarce and expensive, require sophisticated instrumentation, and typically do not allow location of the discharge points. This paper describes the detection of the visual corona and location of the critical corona points of a sphere-plane gap configurations under different pressure conditions ranging from 100 to 20 kPa, covering the pressures typically found in aeronautic environments. The corona detection is made with a low-cost CMOS imaging sensor from both the visible and ultraviolet (UV) spectrum, which allows detection of the discharge points and their locations, thus significantly reducing the complexity and costs of the instrumentation required while preserving the sensitivity and accuracy of the measurements. The approach proposed in this paper can be applied in aerospace applications to prevent the arc tracking phenomenon, which can lead to catastrophic consequences since there is not a clear protection solution, due to the low levels of leakage current involved in the pre-arc phenomenon.Peer ReviewedPostprint (published version

Quantifying Resiliency Risk Metrics through Facility Dispersion

During the last century, airbases were attacked at least 26 times in an effort to destroy the enemy at its base. Attacks on military airbases impose prohibitive losses to critical infrastructure, which in turn impacts the maintenance of air power projection. The primary enemy threat facing critical infrastructure today is the use of ballistic and land-attack cruise missiles to disrupt an airbase’s ability to launch and recover aircraft. Over the last decade, ballistic and cruise missile technology has grown to allow the world’s most powerful countries to achieve a nascent threat to forward operating bases used in theater security campaigns worldwide. Planners can reduce the impact of ballistic and cruise missile attacks on aircraft projection platforms by incorporating a number of resiliency measures, including dispersal of critical infrastructure assets, such as aircraft fuel containment and conveyance equipment. The integration of resiliency measures increases construction costs; therefore, planners need to identify an optimum balance between maximizing airbase resiliency and minimizing site costs. This research presents an airbase resiliency assessment capable of quantifying facility dispersal and risk tolerance levels in an environment threatened by missile attack. Model performance was evaluated using a case study from Osan AB, Republic of Korea. The model’s distinctive capabilities are expected to support planners in the critical task of analyzing and selecting the design strategy that maximizes airbase resiliency against the threat of ballistic and cruise missile attack

Students with Disabilities in Dutch VET: An Exploratory Study

[Excerpt] The inclusion of persons with disabilities in general programmes of vocational training has been called for by the ILO in international labour standards over many years, including standards relating to Human Resources Development and disability-related standards. This call is taken up strongly in the UN Convention on the Rights of Persons with Disabilities which calls on States Parties to take appropriate steps to enable persons with disabilities to have effective access to general tertiary education, vocational and life-long learning without discrimination and on an equal basis with others, and to ensure that reasonable accommodation is provided to that effect. While many countries have expressed commitment to this vision of inclusive vocational training, progress has been limited, even in countries which have adopted policies to promote, and there has been limited analysis of the factors hindering the effective implementation of such policies. It was thus appropriate for the ILO to undertake this exploratory study, to seek to pinpoint elements of policy and practice that might need to be addressed, if these policies on inclusion are to make a difference to persons with disabilities seeking to develop their skills with a view to obtaining decent jobs. The issues identified in this study will hopefully contribute to the wider policy debate, particularly on the matter of instructor preparation for disability inclusion and on the impact of funding arrangements. It will also hopefully stimulate further research to establish whether the patterns identified here are general patterns to be found and tackled elsewhere

Radio Spectrum and the Disruptive Clarity OF Ronald Coase.

In the Federal Communications Commission, Ronald Coase (1959) exposed deep foundations via normative argument buttressed by astute historical observation. The government controlled scarce frequencies, issuing sharply limited use rights. Spillovers were said to be otherwise endemic. Coase saw that Government limited conflicts by restricting uses; property owners perform an analogous function via the "price system." The government solution was inefficient unless the net benefits of the alternative property regime were lower. Coase augured that the price system would outperform the administrative allocation system. His spectrum auction proposal was mocked by communications policy experts, opposed by industry interests, and ridiculed by policy makers. Hence, it took until July 25, 1994 for FCC license sales to commence. Today, some 73 U.S. auctions have been held, 27,484 licenses sold, and $52.6 billion paid. The reform is a textbook example of economic policy success. We examine Coase‘s seminal 1959 paper on two levels. First, we note the importance of its analytical symmetry, comparing administrative to market mechanisms under the assumption of positive transaction costs. This fundamental insight has had enormous influence within the economics profession, yet is often lost in current analyses. This analytical insight had its beginning in his acclaimed early article on the firm (Coase 1937), and continued into his subsequent treatment of social cost (Coase 1960). Second, we investigate why spectrum policies have stopped well short of the property rights regime that Coase advocated, considering rent-seeking dynamics and the emergence of new theories challenging Coase‘s property framework. One conclusion is easily rendered: competitive bidding is now the default tool in wireless license awards. By rule of thumb, about$17 billion in U.S. welfare losses have been averted. Not bad for the first 50 years of this, or any, Article appearing in Volume II of the Journal of Law & Economics.

Supporting looked after children in education

This chapter, aimed principally at teachers and managers in education services, outlines the context and practice issues in relation to looked after children in education in Scotland. The chapter is structured around these headings: the context; looked after children in education; readiness to learn; support at school; joint working

Complex networks and public funding: the case of the 2007-2013 Italian program

In this paper we apply techniques of complex network analysis to data sources representing public funding programs and discuss the importance of the considered indicators for program evaluation. Starting from the Open Data repository of the 2007-2013 Italian Program Programma Operativo Nazionale 'Ricerca e Competitivit\`a' (PON R&C), we build a set of data models and perform network analysis over them. We discuss the obtained experimental results outlining interesting new perspectives that emerge from the application of the proposed methods to the socio-economical evaluation of funded programs.Comment: 22 pages, 9 figure

Ethical and Social Aspects of Self-Driving Cars

As an envisaged future of transportation, self-driving cars are being discussed from various perspectives, including social, economical, engineering, computer science, design, and ethics. On the one hand, self-driving cars present new engineering problems that are being gradually successfully solved. On the other hand, social and ethical problems are typically being presented in the form of an idealized unsolvable decision-making problem, the so-called trolley problem, which is grossly misleading. We argue that an applied engineering ethical approach for the development of new technology is what is needed; the approach should be applied, meaning that it should focus on the analysis of complex real-world engineering problems. Software plays a crucial role for the control of self-driving cars; therefore, software engineering solutions should seriously handle ethical and social considerations. In this paper we take a closer look at the regulative instruments, standards, design, and implementations of components, systems, and services and we present practical social and ethical challenges that have to be met, as well as novel expectations for software engineering.Comment: 11 pages, 3 figures, 2 table