Screening and Sufficiency in Multiobjective Decision Problems with Large Alternative Sets

Portfolio selection problems with combinatorially-large alternative sets can be impossible to evaluate precisely on a reasonable timescale. When portfolios require complex modeling for performance assessment, prohibitive computational processing times can result. Eliminating a small number of alternatives through an intelligent screening process can greatly reduce the number of alternative combinations, thereby decreasing a problem\u27s evaluation time and cost. A methodology was developed for the class of hierarchical portfolio selection problems in which multiple objectives are all judged on the same sub-objectives. First, a novel capability-based alternative screening process was devised to identify and remove poor alternatives, thereby reducing the number of portfolios. Then, a performance-based portfolio screening process was explored to estimate portfolio sufficiency according to the performance requirements of the decision maker. Following the establishment of a set of sufficient portfolios, the analyst can employ higher resolution post-analysis methods to choose a final solution. Finally, the methodology was applied to a portfolio selection problem in which the United States Strategic Command attempts to select an ideal mix of intelligence, surveillance, and reconnaissance assets. After deconstructing the actual objective hierarchy, a set of representative alternatives were evaluated and a variety of screening procedures were applied to demonstrate significant reduction in the number of possible portfolios

Alien Registration- Cote, Joseph D. (Lewiston, Androscoggin County)

https://digitalmaine.com/alien_docs/29338/thumbnail.jp

Low-Mass X-Ray Binaries, Millisecond Radio Pulsars, and the Cosmic Star Formation Rate

We report on the implications of the peak in the cosmic star-formation rate (SFR) at redshift z ~ 1.5 for the resulting population of low-mass X-ray binaries(LMXB) and for that of their descendants, the millisecond radio pulsars (MRP). Since the evolutionary timescales of LMXBs, their progenitors, and their descendants are thought be significant fractions of the time-interval between the SFR peak and the present epoch, there is a lag in the turn-on of the LMXB population, with the peak activity occurring at z ~ 0.5 - 1.0. The peak in the MRP population is delayed further, occurring at z < 0.5. We show that the discrepancy between the birthrate of LMXBs and MRPs, found under the assumption of a stead-state SFR, can be resolved for the population as a whole when the effects of a time-variable SFR are included. A discrepancy may persist for LMXBs with short orbital periods, although a detailed population synthesis will be required to confirm this. Further, since the integrated X-ray luminosity distribution of normal galaxies is dominated by X-ray binaries, it should show strong luminosity evolution with redshift. In addition to an enhancement near the peak (z ~ 1.5) of the SFR due to the prompt turn-on of the relatively short-lived massive X-ray binaries and young supernova remnants, we predict a second enhancement by a factor ~10 at a redshift between ~ 0.5 and ~ 1 due to the delayed turn-on of the LMXB population. Deep X-ray observations of galaxies out to z ~ 1 by AXAF will be able to observe this enhancement, and, by determining its shape as a function of redshift, will provide an important new method for constraining evolutionary models of X-ray binaries.Comment: 13 pages, including 1 figure. Accepted for publication in ApJ Letter

Interannual Variability of Landfast Ice Thickness in the Canadian High Arctic, 1950-89

A physical one-dimensional heat transfer model of fast ice growth was used to investigate the interannual variability of maximum fast ice thickness at four sites in the High Arctic over the period 1950-89. The insulating role of snow cover was found to be the most important factor, explaining 30-60% of the variance in maximum ice thickness values. Other snow-related processes such as slushing and density variations were estimated to explain a further 15-30% of the variance. In contrast, annual variation in air temperatures explained less than 4% of the variance in maximum ice thickness. No evidence was found for the systematic ice thinning trend anticipated from greenhouse gas-induced global warming. However, recent ice thinning and thickening trends at two sites (Alert and Resolute) are consistent with changes in the average depth of snow covering the ice and may be explained by changes in cyclone frequencies. A response surface sensitivity analysis following Fowler and de Freitas (1900) indicated the High Arctic landfast ice regime would be more sensitive to air temperature variations under a warmer, snowier environment.Key words: landfast ice, snow, interannual variability, climate change, Canadian High ArcticR&Eacute;SUM&Eacute;. On s&rsquo;est servi d&rsquo;un mod&egrave;le physique de transfert unidimensionnel de chaleur de la croissance de la banquise c&ocirc;ti&egrave;re pour &eacute;tudier la variabilit&eacute; interannuelle de l&rsquo;&eacute;paisseur maximale de la banquise c&ocirc;ti&egrave;re &agrave; quatre stations de l&rsquo;Arctique septentrional au cours de la p&eacute;riode allant de 1950 &agrave; 1989. Le r&ocirc;le d&rsquo;isolant de la couche de neige s&rsquo;est r&eacute;v&eacute;l&eacute; le facteur le plus important, r&eacute;pondant pour 30 &agrave; 60 p. 100 de l&rsquo;&eacute;cart observ&eacute; dans les &eacute;paisseurs maximales de glace. On estime qu&rsquo;une autre partie (15 &agrave; 30 p. 100) de l&rsquo;&eacute;cart d&eacute;coule d&rsquo;autres processus li&eacute;s &agrave; la neige, comme la variation de la densit&eacute; et la gadoue. En revanche, la variation annuelle des temp&eacute;ratures de l&rsquo;air est intervenue pour moins de 4 p. 100 de l&rsquo;&eacute;cart observ&eacute; dans les &eacute;paisseurs maximales de la glace. On n&rsquo;a relev&eacute; aucune tendance &agrave; l&rsquo;amincissement syst&eacute;matique de la glace, tendance pr&eacute;vue du fait du r&eacute;chauffement du globe provoqu&eacute; par les gaz &agrave; effet de serre. Toutefois, les r&eacute;centes tendances &agrave; l&rsquo;amincissement et &agrave; l&rsquo;&eacute;paississement enregistr&eacute;es &agrave; deux stations (Alert et Resolute) sont compatibles avec la hauteur moyenne de la neige qui recouvre la glace. Ce fait tient peut-&ecirc;tre &agrave; la modification de la fr&eacute;quence des cyclones. D&rsquo;apr&egrave;s une analyse de la r&eacute;action de surface ex&eacute;cut&eacute;e suivant la m&eacute;thode de Fowler et de Freitas (1990), le r&eacute;gime de la glace c&ocirc;ti&egrave;re de l&rsquo;Arctique septentrional est plus sensible &agrave; la variation de la temp&eacute;rature de l'air dans un milieu plus neigeux et plus chaud.Mots cl&eacute;s: banquise c&ocirc;ti&egrave;re, neige, variabilit&eacute; interannuelle, changement climatique, Arctique septentrional canadie

Management of incidentally detected heart murmurs in dogs and cats

A dog or a cat has an incidentally detected heart murmur if the murmur is an unexpected discovery during a veterinary consultation that was not initially focused on the cardiovascular system. This document presents approaches for managing dogs and cats that have incidentally-detected heart murmurs, with an emphasis on murmur characteristics, signalment profiling, and multifactorial decision-making to choose an optimal course for a given patient

A Megacam Survey of Outer Halo Satellites. IV. Two foreground populations possibly associated with the Monoceros substructure in the direction of NGC2419 and Koposov2

The origin of the Galactic halo stellar structure known as the Monoceros ring is still under debate. In this work, we study that halo substructure using deep CFHT wide-field photometry obtained for the globular clusters NGC2419 and Koposov2, where the presence of Monoceros becomes significant because of their coincident projected position. Using Sloan Digital Sky Survey photometry and spectroscopy in the area surrounding these globulars and beyond, where the same Monoceros population is detected, we conclude that a second feature, not likely to be associated with Milky Way disk stars along the line-of-sight, is present as foreground population. Our analysis suggests that the Monoceros ring might be composed of an old stellar population of age t ~ 9Gyr and a new component ~ 4Gyr younger at the same heliocentric distance. Alternatively, this detection might be associated with a second wrap of Monoceros in that direction of the sky and also indicate a metallicity spread in the ring. The detection of such a low-density feature in other sections of this halo substructure will shed light on its nature.Comment: 10 pages, 10 figures, accepted for publication in Ap

Satellite data relay and platform locating in oceanography. Report of the In Situ Ocean Science Working Group

The present and future use of satellites to locate offshore platforms and relay data from in situ sensors to shore was examined. A system of the ARGOS type will satisfy the increasing demand for oceanographic information through data relay and platform location. The improved ship navigation provided by the Global Positioning System (GPS) will allow direct observation of currents from underway ships. Ocean systems are described and demand estimates on satellite systems are determined. The capabilities of the ARGOS system is assessed, including anticipated demand in the next decade

Patient Perspectives on Medication Assisted Therapy in Vermont

Introduction. Medication-Assisted Therapy (MAT) for opioid addiction has dramatically increased in Vermont, supported by a novel statewide system that integrates specialty treatment centers ( Hubs ) with primary care office-based opioid therapy ( Spokes ). In 2010, Vermont had the highest per capita buprenorphine use in the US. Previous studies of patient perspectives of MAT have identified social barriers, rigid program rules, and concerns about withdrawal and relapse as common causes of treatment failure. Our goal was to elicit patient perspectives on barriers and enablers of successful MAT to further inform system refinement. Methods. An interview guide was developed based on previous literature as well as discussions with program leadership, staff and clinicians, and community stakeholders. Responses were organized using thematic content analysis with consensus across seven interviewers and two analysts. The interviews were conducted with 44 patients enrolled in MAT at two Hub sites in Burlington, VT in October 2016. Results. The median age of subjects was 34 years, 34% were employed at least part-time, and 72% were female. Half reported a mental health condition and 20% reported chronic pain. Barriers included transportation (25%), lack of stable housing, and stigma (41%). Enablers included feeling supported (82% felt well-supported; 52% felt supported by healthcare professionals). Subjects expressed high confidence in the treatment system and high self-efficacy for sobriety. Conclusions. Patients in MAT have complex medical, mental health, social, personal, and work lives. A comprehensive system that addresses this wide range of domains is critical to achieving optimal outcomes.https://scholarworks.uvm.edu/comphp_gallery/1245/thumbnail.jp