Reconfiguration of distribution networks to minimize loss and disruption costs using genetic algorithms

In this paper a computational implementation of an evolutionary algorithm (EA) is shown in order to tackle the problem of reconfiguring radial distribution systems. The developed module considers power quality indices such as long duration interruptions and customer process disruptions due to voltage sags, by using the Monte Carlo simulation method. Power quality costs are modeled into the mathematical problem formulation, which are added to the cost of network losses. As for the EA codification proposed, a decimal representation is used. The EA operators, namely selection, recombination and mutation, which are considered for the reconfiguration algorithm, are herein analyzed. A number of selection procedures are analyzed, namely tournament, elitism and a mixed technique using both elitism and tournament. The recombination operator was developed by considering a chromosome structure representation that maps the network branches and system radiality, and another structure that takes into account the network topology and feasibility of network operation to exchange genetic material. The topologies regarding the initial population are randomly produced so as radial configurations are produced through the Prim and Kruskal algorithms that rapidly build minimum spanning trees. (C) 2009 Elsevier B.V. All rights reserved.

Tariff Equivalent of Technical Barriers to Trade with Imperfect Substitution and Trade Costs, November 2005

The price-wedge method yields a tariff-equivalent estimate of technical barriers to trade (TBT). An extension of this method accounts for imperfect substitution between domestic and imported goods and incorporates recent findings on trade costs. We explore the sensitivity of this revamped TBT estimate to its key determinants (substitution elasticity, preference for home good, and trade cost). We use the augmented approach to investigate the ongoing US-Japan apple trade dispute and find that removing the Japanese TBT would yield limited export gains to the United States. We then draw policy implications of our findings.

Cumulative Costs of Caries Prevention and Treatment in Children - with Special Reference to Work Division and Cohort Effect

Lapsen karieshoidon kustannuskertymän muutokset ja karieshoidon toimintakäytäntöjen yhteys kustannuksiin Tutkimuksen tavoitteena oli mitata terveyskeskuksessa hoidettavien lasten karieshoidon kumulatiivisia kustannuksia ja verrata niitä kahden erilaisen toimintatavan välillä. Lisäksi tarkasteltiin lasten hampaiden terveyttä. Tutkimus tehtiin julkisen palvelutuottajan näkökulmasta. Tutkimusaineisto kerättiin Kemin ja Tornion terveyskeskusten suun terveydenhuollon potilaskertomuksista. Kemin kohortit 1980, 1983 ja 1986 (n = 600) ja Tornion kohortit 1980 ja 1992 (n = 400) edustivat perinteistä ja Kemin kohortit 1989, 1992 ja 1995 (n = 600) uutta toimintatapaa työnjaon ja ehkäisyn ajoituksen suhteen. Kohortteja ja kaupunkeja verrattiin hampaiden terveyden (dmft/DMFT = 0 ja dmft ja DMFT keskiarvot 5 ja 12 vuoden iässä) ja voimavarojen käytön suhteen. Panoskäyttö johdettiin käyntimäärien avulla laskennallisen työajan kautta. Kustannuskertymät muodostettiin käyttämällä henkilöstömenoista laskettuja suorittajakohtaisia yksikkökustannuksia. Panoskäytön ja yksikkökustannusten kautta muodostettiin kustannuskertymät. Kustannusten ja terveysvaikutusten suhteita arvioitiin kustannus-vaikuttavuusanalyysissä. Suuhygienistien työpanosta hyödyntävällä varhaisen ehkäisyn toimintamallilla saavutettiin vähäisemmin kustannuksin alle kouluiässä parempi ja kouluiässä yhtä hyvä hammasterveys kuin perinteisellä, enemmän hammaslääkärien työpanokseen perustuvalla tavalla. Karieksen hoitoon liittyvien käyntien määrä oli nuorimmissa syntymävuosikohorteissa pienempi kuin vanhimmissa kohorteissa. Käynnit hammaslääkärissä vähenivät eniten. Toimintatavalla oli merkittävä vaikutus lapsen karieshoidon kokonaiskustannuksiin. Herkkyysanalyysin mukaan karieshoidon kustannukset olivat työnjakoa hyödyntämällä kolmanneksen pienemmät, kuin jos hoidon suorittajana olisi ollut ainoastaan hammaslääkäri-hoitaja työpari. Lasten karieshoidon kustannusvaikuttavuus kohentui molemmissa terveyskeskuksissa nuoremmissa kohorteissa vanhempiin verrattuna. Suun terveydenhuollon potilaskertomuksia olisi hyödynnettävä toiminnan kehittämisessä. Varhaisen ehkäisyn avulla voitaisiin kaikkien suun terveydenhuollon ammattihenkilöiden työpanos kohdentaa kustannustehokkaasti.

Bayes estimates of distance-to-market: Transactions costs, cooperatives and milk-market development in the Ethiopian highlands

Rationalizing non-participation as a resource deficiency in the household, this paper identifies strategies for milk-market development in the Ethiopian highlands. The additional amounts of covariates required for Positive marketable surplus -'distances-to market'-are computed from a model in which production and sales are correlated; sales are left-censored at some Unobserved thresholds production efficiencies are heterogeneous: and the data are in the form of a panel. Incorporating these features into the modeling exercise ant because they are fundamental to the data-generating environment. There are four reasons. First, because production and sales decisions are enacted within the same household, both decisions are affected by the same exogenous shocks, and production and sales are therefore likely to be correlated. Second. because selling, involves time and time is arguably the most important resource available to a subsistence household, the minimum Sales amount is not zero but, rather, some unobserved threshold that lies beyond zero. Third. the Potential existence of heterogeneous abilities in management, ones that lie latent from the econometrician's perspective, suggest that production efficiencies should be permitted to vary across households. Fourth, we observe a single set of households during multiple visits in a single production year. The results convey clearly that institutional and production) innovations alone are insufficient to encourage participation. Market-precipitating innovation requires complementary inputs, especially improvements in human capital and reductions in risk. Copyright (c) 20 08 John Wiley & Sons, Ltd.

Enabling older people to stay at home: The costs of substituting and supplementing care with assistive technology

A wide-ranging multiprofessional research project explored issues relating to the introduction of assistive technology into the existing homes of older people in order to provide them with the opportunity to remain at home. The financial relationship between assistive technology and packages of formal care was also explored. The costs of residential care and those of a number of packages containing differing quantities of assistive technology, formal care and informal care were compared. The analyses provide a strong financial case for substituting and/or supplementing formal care with assistive technology, even for individuals with quite disabling conditions. Although needs and hence the cost of provision rise with an increasing level of disability, the savings in care costs accrue quickly. The consideration of a variety of users with different needs and informal care provision, and occupying a very wide range of housing, leads to the conclusion that in comparison with traditional care packages, at worst, incorporating significant amounts of assistive technology into care packages is cost neutral, but that with careful specification of assistive technology major savings are feasible.

Using ecological thresholds to evaluate the costs and benefits of set-asides in a biodiversity hotspot

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Temporomandibular disorders/myoarthropathy of the masticatory system. Costs of dental treatment and reimbursement by Swiss federal insurance agencies according to the Health Care Benefits Ordinance (KLV)

The goal of the study was to calculate the direct costs of therapy for patients with MAP. This retrospective study included 242 MAP patients treated at the Department of Prosthodontics of the University of Bern between 2003 and 2006. The following parameters were collected from the clinical charts: chief complaint, diagnosis, treatment modalities, total costs, costs of the dental technician, number of appointments, average cost per appointment, length of treatment, and services reimbursed by health insurance agencies. The average age of the patients was 40.4 ± 17.3 years (76.4% women, 23.6% men). The chief complaint was pain in 91.3% of the cases, TMJ noises (61.2%) or limitation of mandibular mobility (53.3%). Tendomyopathy (22.3%), disc displacement (22.4%), or a combination of the two (37.6%) were more often diagnosed than arthropathy alone (7.4%). Furthermore, 10.3% of the MAP patients had another primary diagnosis (tumor, trauma, etc.). Patients were treated with counseling and exercises (36.0%), physiotherapy (23.6%), or occlusal splints (32.6%). The cost of treatment reached 644 Swiss francs for four appointments spread over an average of 21 weeks. In the great majority of cases, patients can be treated with inexpensive modalities. 99.9% of the MAP cases submitted to the insurance agencies were reimbursed by them, in accordance with Article 17d1-3 of the Swiss Health Care Benefits Ordinance (KLV) and Article 25 of the Federal Health Insurance Act (KVG). The costs of treatment performed by dentists remain modest. The more time-consuming services, such as providing information, counseling and instructions, are poorly remunerated. This aspect should be re-evaluated in a future revision of the tariff schedule.

Relationship of hospital volume to patient mortality, length of stay and total costs in patients receiving brain surgery for cancer: A nationwide analysis

Better morbidity and mortality outcomes associated with increased hospital procedural volume have been demonstrated across a number of different medical procedures. Existence of such a volume-outcome relationship is posited to lead to increased specialization of care, such that patients requiring specific procedures are funneled to physicians and hospitals that achieve a minimum volume of such procedures each year. In this study, the 2009 Nationwide Inpatient Sample is used to examine the relationship between hospital volume and patient outcome among patients undergoing procedures related to malignant brain cancer. Multiple regression models were used to examine the impact of hospital volume on length of inpatient stay and cost of inpatient stay; logistic regression was used to examine the impact of hospital volume on morbidity. Hospital volume was found to be a significant predictor of both length of stay and cost of stay. Hospital volume was associated with a lower length of stay, but was also associated with increased costs. Hospital volume was not found to be a statistically significant predictor of morbidity, though less than three percent of this sample died while in the hospital. Volume is indeed a significant predictor of outcome for procedures related to brain malignancies, though further research regarding the cost of such procedures is recommended.^

Development of mathematical models to elaborate strategies, select alternatives and development of plans for adaptation of communities to climate change in different geographical areas including costs to implement it.

There is evidence that the climate changes and that now, the change is influenced and accelerated by the CO2 augmentation in atmosphere due to combustion by humans. Such ?Climate change? is on the policy agenda at the global level, with the aim of understanding and reducing its causes and to mitigate its consequences. In most countries and international organisms UNO (e.g. Rio de Janeiro 1992), OECD, EC, etc . . . the efforts and debates have been directed to know the possible causes, to predict the future evolution of some variable conditioners, and trying to make studies to fight against the effects or to delay the negative evolution of such. The Protocol of Kyoto 1997 set international efforts about CO2 emissions, but it was partial and not followed e.g. by USA and China . . . , and in Durban 2011 the ineffectiveness of humanity on such global real challenges was set as evident. Among all that, the elaboration of a global model was not boarded that can help to choose the best alternative between the feasible ones, to elaborate the strategies and to evaluate the costs, and the authors propose to enter in that frame for study. As in all natural, technological and social changes, the best-prepared countries will have the best bear and the more rapid recover. In all the geographic areas the alternative will not be the same one, but the model must help us to make the appropriated decision. It is essential to know those areas that are more sensitive to the negative effects of climate change, the parameters to take into account for its evaluation, and comprehensive plans to deal with it. The objective of this paper is to elaborate a mathematical model support of decisions, which will allow to develop and to evaluate alternatives of adaptation to the climatic change of different communities in Europe and Latin-America, mainly in especially vulnerable areas to the climatic change, considering in them all the intervening factors. The models will consider criteria of physical type (meteorological, edaphic, water resources), of use of the ground (agriculturist, forest, mining, industrial, urban, tourist, cattle dealer), economic (income, costs, benefits, infrastructures), social (population), politician (implementation, legislation), educative (Educational programs, diffusion) and environmental, at the present moment and the future. The intention is to obtain tools for aiding to get a realistic position for these challenges, which are an important part of the future problems of humanity in next decades.

Development of mathematical models to elaborate strategies, to select alternatives and the development of plans for the adaptation of communities to climate change in different geographical areas including costs to implement it

Climate change is on the policy agenda at the global level, with the aim of understanding and reducing its causes and to mitigate its consequences. In most of the countries and international organisms UNO, OECD, EC, etc … the efforts and debates have been directed to know the possible causes, to predict the future evolution of some variable conditioners, and trying to make studies to fight against the effects or to delay the negative evolution of such. Nevertheless, the elaboration of a global model was not boarded that can help to choose the best alternative between the feasible ones, to elaborate the strategies and to evaluate the costs. As in all natural, technological and social changes, the best-prepared countries will have the best bear and the more rapid recover. In all the geographic areas the alternative will not be the same one, but the model should help us to make the appropriated decision. It is essential to know those areas that are more sensitive to the negative effects of climate change, the parameters to take into account for its evaluation, and comprehensive plans to deal with it. The objective of this paper is to elaborate a mathematical model support of decisions, that will allow to develop and to evaluate alternatives of adaptation to the climatic change of different communities in Europe and Latin-America, mainly, in vulnerable areas to the climatic change, considering in them all the intervening factors. The models will take into consideration criteria of physical type (meteorological, edaphic, water resources), of use of the ground (agriculturist, forest, mining, industrial, urban, tourist, cattle dealer), economic (income, costs, benefits, infrastructures), social (population), politician (implementation, legislation), educative (Educational programs, diffusion), sanitary and environmental, at the present moment and the future.

Investigation of alternative aqueduct systems to serve southern California : Feather River and delta diversion projects : Appendix C, procedure for estimating costs of tunnel construction.

Mode of access: Internet.