956 resultados para Multi-Objective
Resumo:
We extend to score, Wald and difference test statistics the scaled and adjusted corrections to goodness-of-fit test statistics developed in Satorra and Bentler (1988a,b). The theory is framed in the general context of multisample analysis of moment structures, under general conditions on the distribution of observable variables. Computational issues, as well as the relation of the scaled and corrected statistics to the asymptotic robust ones, is discussed. A Monte Carlo study illustrates thecomparative performance in finite samples of corrected score test statistics.
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In this paper, we discuss pros and cons ofdifferent models for financial market regulationand supervision and we present a proposal forthe re-organisation of regulatory and supervisoryagencies in the Euro Area. Our arguments areconsistent with both new theories and effectivebehaviour of financial intermediaries inindustrialized countries. Our proposed architecturefor financial market regulation is based on theassignment of different objectives or "finalities"to different authorities, both at the domesticand the European level. According to thisperspective, the three objectives of supervision- microeconomic stability, investor protectionand proper behaviour, efficiency and competition- should be assigned to three distinct Europeanauthorities, each one at the centre of a Europeansystem of financial regulators and supervisorsspecialized in overseeing the entire financialmarket with respect to a single regulatoryobjective and regardless of the subjective natureof the intermediaries. Each system should bestructured and organized similarly to the EuropeanSystem of Central Banks and work in connectionwith the central bank which would remain theinstitution responsible for price and macroeconomicstability. We suggest a plausible path to buildour 4-peak regulatory architecture in the Euro area.
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BACKGROUND AND PURPOSE: Multi-phase postmortem CT angiography (MPMCTA) is increasingly being recognized as a valuable adjunct medicolegal tool to explore the vascular system. Adequate interpretation, however, requires knowledge about the most common technique-related artefacts. The purpose of this study was to identify and index the possible artefacts related to MPMCTA. MATERIAL AND METHODS: An experienced radiologist blinded to all clinical and forensic data retrospectively reviewed 49 MPMCTAs. Each angiographic phase, i.e. arterial, venous and dynamic, was analysed separately to identify phase-specific artefacts based on location and aspect. RESULTS: Incomplete contrast filling of the cerebral venous system was the most commonly encountered artefact, followed by contrast agent layering in the lumen of the thoracic aorta. Enhancement or so-called oedematization of the digestive system mucosa was also frequently observed. CONCLUSION: All MPMCTA artefacts observed and described here are reproducible and easily identifiable. Knowledge about these artefacts is important to avoid misinterpreting them as pathological findings.
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Several studies have reported high performance of simple decision heuristics multi-attribute decision making. In this paper, we focus on situations where attributes are binary and analyze the performance of Deterministic-Elimination-By-Aspects (DEBA) and similar decision heuristics. We consider non-increasing weights and two probabilistic models for the attribute values: one where attribute values are independent Bernoulli randomvariables; the other one where they are binary random variables with inter-attribute positive correlations. Using these models, we show that good performance of DEBA is explained by the presence of cumulative as opposed to simple dominance. We therefore introduce the concepts of cumulative dominance compliance and fully cumulative dominance compliance and show that DEBA satisfies those properties. We derive a lower bound with which cumulative dominance compliant heuristics will choose a best alternative and show that, even with many attributes, this is not small. We also derive an upper bound for the expected loss of fully cumulative compliance heuristics and show that this is moderateeven when the number of attributes is large. Both bounds are independent of the values ofthe weights.
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This paper describes a methodology to estimate the coefficients, to test specification hypothesesand to conduct policy exercises in multi-country VAR models with cross unit interdependencies, unit specific dynamics and time variations in the coefficients. The framework of analysis is Bayesian: a prior flexibly reduces the dimensionality of the model and puts structure on the time variations; MCMC methods are used to obtain posterior distributions; and marginal likelihoods to check the fit of various specifications. Impulse responses and conditional forecasts are obtained with the output of MCMC routine. The transmission of certain shocks across countries is analyzed.
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The old, understudied electoral system composed of multi-member districts, open ballot and plurality rule is presented as the most remote scene of the origin of both political parties and new electoral systems. A survey of the uses of this set of electoral rules in different parts of the world during remote and recent periods shows its wide spread. A model of voting by this electoral system demonstrates that, while it can produce varied and pluralistic representation, it also provides incentives to form factional or partisan candidacies. Famous negative reactions to the emergence of factions and political parties during the 18th and 19th centuries are reinterpreted in this context. Many electoral rules and procedures invented since the second half of the 19th century, including the Australian ballot, single-member districts, limited and cumulative ballots, and proportional representation rules, derived from the search to reduce the effects of the originating multi-member district system in favor of a single party sweep. The general relations between political parties and electoral systems are restated to account for the foundational stage here discussed.
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The taxonomy of Bambusoideae is in a state of flux and phylogenetic studies are required to help resolve systematic issues. Over 60 taxa, representing all subtribes of Bambuseae and related non-bambusoid grasses were sampled. A combined analysis of five plastid DNA regions, trnL intron, trnL-F intergenic spacer, atpB-rbcL intergenic spacer, rps16 intron, and matK, was used to study the phylogenetic relationships among the bamboos in general and the woody bamboos in particular. Within the BEP clade (Bambusoideae s.s., Ehrhartoideae, Pooideae), Pooideae were resolved as sister to Bambusoideae s.s. Tribe Bambuseae, the woody bamboos, as currently recognized were not monophyletic because Olyreae, the herbaceous bamboos, were sister to tropical Bambuseae. Temperate Bambuseae were sister to the group consisting of tropical Bambuseae and Olyreae. Thus, the temperate Bambuseae would be better treated as their own tribe Arundinarieae than as a subgroup of Bambuseae. Within the tropical Bambuseae, neotropical Bambuseae were sister to the palaeotropical and Austral Bambuseae. In addition, Melocanninae were found to be sister to the remaining palaeotropical and Austral Bambuseae. We discuss phylogenetic and morphological patterns of diversification and interpret them in a biogeographic context.
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The Iowa Transportation Improvement Program (Program) is published to inform Iowans of planned investments in our state's transportation system. The Iowa Transportation Commission (Commission) and Iowa Department of Transportation (Iowa DOT) are committed to programming those investments in a fiscally responsible manner. Iowa's transportation system is multi-modal; therefore, the Program encompasses investments in aviation, transit, railroads, trails, and highways. A major component of the Program is the highway section. The FY2009-2013 highway section is financially balanced and was developed to achieve several objectives. The Commission's primary highway investment objective is the safety, maintenance and preservation of Iowa's existing highway system. The Commission has allocated an annual average of $321 million to achieve this objective. This includes $185 million in 2009 and $170 million annually in years 2010-2013 for preserving the interstate system. It includes $114 million in 2009, $100 million in 2010 and $90 million annually in years 2011-2013 for non-interstate pavement preservation. It includes $38 million annually in 2009 and 2010, and $35 million annually in years 2011-2013 for non-interstate bridges. In addition, $15 million annually is allocated for safety projects. However, due to increasing construction costs, flattened revenues and overall highway systems needs, the Commission acknowledges that insufficient funds are being invested in the maintenance and preservation of the existing highway system. Another objective involves investing in projects that have received funding from the federal transportation act and/or subsequent federal transportation appropriation acts. In particular, funding is being used where it will complete a project, corridor or useable segment of a larger project. As an investment goal, the Commission also wishes to advance highway projects that address the state's highway capacity and economic development needs. Projects that address these needs and were included for completion in the previous program have been advanced into this year's Program to maintain their scheduled completion. This program also includes a small number of other projects that generally either represent a final phase of a partially programmed project or an additional segment of a partially completed corridor. The TIME-21 bill, Senate File 2420, signed by Governor Chet Culver on April 22, provides additional funding to cities, counties and the Iowa DOT for road improvements. This will result in additional revenue to the Primary Road Fund beginning in the second half of FY2009 and gradually increase over time. The additional funding will be included in future highway programming objectives and proposals and is not reflected in this highway program. The Iowa DOT and Commission appreciate the public's involvement in the state's transportation planning process. Comments received personally, by letter, or through participation in the Commission's regular meetings or public input meetings held around the state each year are invaluable in providing guidance for the future of Iowa's transportation system. It should be noted that this document is a planning guide. It does not represent a binding commitment or obligation of the Commission or Iowa DOT, and is subject to change. You are invited to visit the Iowa DOT's Web site at iowadot.gov for additional and regular updates about the department's programs and activities.
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The need for integration in the supply chain management leads us to considerthe coordination of two logistic planning functions: transportation andinventory. The coordination of these activities can be an extremely importantsource of competitive advantage in the supply chain management. The battle forcost reduction can pass through the equilibrium of transportation versusinventory managing costs. In this work, we study the specific case of aninventory-routing problem for a week planning period with different types ofdemand. A heuristic methodology, based on the Iterated Local Search, isproposed to solve the Multi-Period Inventory Routing Problem with stochasticand deterministic demand.
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We address the problem of scheduling a multi-station multiclassqueueing network (MQNET) with server changeover times to minimizesteady-state mean job holding costs. We present new lower boundson the best achievable cost that emerge as the values ofmathematical programming problems (linear, semidefinite, andconvex) over relaxed formulations of the system's achievableperformance region. The constraints on achievable performancedefining these formulations are obtained by formulatingsystem's equilibrium relations. Our contributions include: (1) aflow conservation interpretation and closed formulae for theconstraints previously derived by the potential function method;(2) new work decomposition laws for MQNETs; (3) new constraints(linear, convex, and semidefinite) on the performance region offirst and second moments of queue lengths for MQNETs; (4) a fastbound for a MQNET with N customer classes computed in N steps; (5)two heuristic scheduling policies: a priority-index policy, anda policy extracted from the solution of a linear programmingrelaxation.
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BACKGROUND: To determine the outcome of patients with brain metastasis (BM) from lung cancer treated with an external beam radiotherapy boost (RTB) after whole brain radiotherapy (WBRT). METHODS: A total of 53 BM patients with lung cancer were treated sequentially with WBRT and RTB between 1996 and 2008 according to our institutional protocol. Mean age was 58.8 years. The median KPS was 90. Median recursive partitioning analysis (RPA) and graded prognostic assessment (GPA) grouping were 2 and 2.5, respectively. Surgery was performed on 38 (71%) patients. The median number of BM was 1 (range, 1-3). Median WBRT and RTB combined dose was 39 Gy (range, 37.5-54). Median follow-up was 12.0 months. RESULTS: During the period of follow-up, 37 (70%) patients died. The median overall survival (OS) was 14.5 months. Only 13 patients failed in the brain. The majority of patients (n = 29) failed distantly. The 1-year OS, -local control, extracranial failure rates were 61.2%, 75.2% and 60.8%, respectively. On univariate analysis, improved OS was found to be significantly associated with total dose (< or = 39 Gy vs. > 39 Gy; p < 0.01), age < 65 (p < 0.01), absence of extracranial metastasis (p < 0.01), GPA > or = 2.5 (p = 0.01), KPS > or = 90 (p = 0.01), and RPA < 2 (p = 0.04). On multivariate analysis, total dose (p < 0.01) and the absence of extracranial metastasis (p = 0.03) retained statistical significance. CONCLUSIONS: The majority of lung cancer patients treated with WBRT and RTB progressed extracranially. There might be a subgroup of younger patients with good performance status and no extracranial disease who may benefit from dose escalation after WBRT to the metastatic site.
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Three types of garnet have been distinguished in pelitic schists from an epidote-blueschist-facies unit of the Ambin and South Vanoise Brianconnais massifs on the basis of texture, chemical zoning and mineral inclusion characterization. Type-1 garnet cores with high Mn/Ca ratios are interpreted as pre-Alpine relicts, whereas Type-1 garnet rims, Type-2 inclusion-rich porphyroblasts and smaller Type-3 garnets are Alpine. The latter are all characterized by low Mn/Ca ratios and a coexisting mineral assemblage of blue amphibole, high-Si phengite, epidote and quartz. Prograde growth conditions during Alpine D-1 high-pressure (HP) metamorphism are recorded by a decrease in Mn and increase in Fe (+/-Ca) in the Type-2 garnets, culminating in peak P-T conditions of 14-16 kbar and 500degreesC in the deepest parts of the Ambin dome. The multistage growth history of Type-1 garnets indicates a polymetamorphic history for the Ambin and South Vanoise massifs; unfortunately, no age constraints are available. The new metamorphic constraints on the Alpine event in the massifs define a metamorphic T `gap' between them and their surrounding cover (Brianconnais and upper Schistes Lustres units), which experienced metamorphism only in the stability field of carpholite-lawsonite (T < 400degreesC). These data and supporting structural studies confirm that the Ambin and South Vanoise massifs are slices of `eclogitized' continental crust tectonically extruded within the Schistes Lustres units and Brianconnais covers. The corresponding tectonic contacts with top-to-east movement are responsible for the juxtaposition of lower-grade metamorphic units on the Ambin and South Vanoise massifs.