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System Data (system + data)
Selected AbstractsCalculation of Posterior Probabilities for Bayesian Model Class Assessment and Averaging from Posterior Samples Based on Dynamic System DataCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2010Sai Hung Cheung Because of modeling uncertainty, a set of competing candidate model classes may be available to represent a system and it is then desirable to assess the plausibility of each model class based on system data. Bayesian model class assessment may then be used, which is based on the posterior probability of the different candidates for representing the system. If more than one model class has significant posterior probability, then Bayesian model class averaging provides a coherent mechanism to incorporate all of these model classes in making probabilistic predictions for the system response. This Bayesian model assessment and averaging requires calculation of the evidence for each model class based on the system data, which requires the evaluation of a multi-dimensional integral involving the product of the likelihood and prior defined by the model class. In this article, a general method for calculating the evidence is proposed based on using posterior samples from any Markov Chain Monte Carlo algorithm. The effectiveness of the proposed method is illustrated by Bayesian model updating and assessment using simulated earthquake data from a ten-story nonclassically damped building responding linearly and a four-story building responding inelastically. [source] Accessible and Free: Party System Data on JapanASIAN POLITICS AND POLICY, Issue 4 2010Katie Anne Cahill-Rincón No abstract is available for this article. [source] Using Web 2.0 for scientific applications and scientific communitiesCONCURRENCY AND COMPUTATION: PRACTICE & EXPERIENCE, Issue 5 2009Marlon E. Pierce Abstract Web 2.0 approaches are revolutionizing the Internet, blurring lines between developers and users and enabling collaboration and social networks that scale into the millions of users. As discussed in our previous work, the core technologies of Web 2.0 effectively define a comprehensive distributed computing environment that parallels many of the more complicated service-oriented systems such as Web service and Grid service architectures. In this paper we build upon this previous work to discuss the applications of Web 2.0 approaches to four different scenarios: client-side JavaScript libraries for building and composing Grid services; integrating server-side portlets with ,rich client' AJAX tools and Web services for analyzing Global Positioning System data; building and analyzing folksonomies of scientific user communities through social bookmarking; and applying microformats and GeoRSS to problems in scientific metadata description and delivery. Copyright © 2009 John Wiley & Sons, Ltd. [source] Three-dimensional elastic earthquake modelling based on integrated seismological and InSAR data: the Mw= 7.2 Nuweiba earthquake, gulf of Elat/Aqaba 1995 NovemberGEOPHYSICAL JOURNAL INTERNATIONAL, Issue 3 2003G. Shamir SUMMARY The Nuweiba earthquake (1995 November 22; Mw= 7.2), the largest seismic event along the Dead Sea Transform (DST) in at least 160 yr, ruptured 45,50 km along the Aragonese segment of the left-stepping strike-slip fault system occupying the gulf of Elat/Aqaba (southern segment of the DST). The rupture initiated in a partly normal, low-slip first subevent near the southern end of the fault and propagated unilaterally north-northeastward as a high-slip, nearly pure sinistral second subevent, which was responsible for over 90 per cent of the total seismic moment. The source mechanism and slip distribution, derived from inversion of teleseismic broad-band waveforms, are used to construct a 3-D elastic model of the earthquake based on the boundary elements method, resulting in the full 3-D displacement and stress fields induced by the earthquake. In the absence of sufficient Global Positioning System data, the only other constraints on the geometry and slip distribution of the rupture are provided by interferometric synthetic aperture radar (InSAR) measurements spanning the coseismic and early post-seismic period. We calculate simulated interferograms by transforming the calculated surface displacement field into the satellite coordinate system and comparing them with the observed interferograms. The model parameters are then iteratively modified until a best-fitting model is obtained, providing a refined set of static source parameters for the mainshock. This model is then used to calculate the static Coulomb stress changes induced by the mainshock on the step-over faults, suggesting that the major (Mw, 5) aftershocks in the first eight post-seismic months were triggered by small changes (<1 bar) in the left-lateral Coulomb stress, with effective friction coefficient not higher than 0.2. Aftershock distribution and mechanisms indicate that the available Coulomb stress dropped below the frictional strength of the fault but was not complete. [source] Agricultural land use and Skylark Alauda arvensis: a case study linking a habitat association model to spatially explicit change scenariosIBIS, Issue 1 2010NIGEL D. BOATMAN The development of forward scenarios is a useful method of envisaging the environmental implications of potential changes in land use, as a tool for policy development. In this paper, a spatially explicit case study is used to provide insight into the environmental impacts of Common Agricultural Policy reform on Skylark Alauda arvensis, a species which is widespread on arable farmland, breeds in crops and has declined in recent decades. A generalized linear mixed model was used to estimate Skylark breeding population densities in different crops, using survey data collected from farms in the east of England, supplemented by the literature. Model outputs were then used to predict Skylark densities in an East Anglian Joint Character Area dominated by arable cropping. Predicted densities were mapped at field level using GIS, based on actual cropping derived from Integrated Administration and Control System data collected for the administration of subsidy payments. Three future scenarios were then created, based on expert opinion of potential changes in cropping over the next 5 years, and potential changes in Skylark density mapped on the basis of the predicted changes in cropping patterns. Overall, Skylark densities were predicted to decrease on average by 11,14% under ,market-led' (increasing wheat and oilseed rape, reduced set-aside) and ,energy crop' (5% area under short rotation coppice) scenarios, but remained virtually unchanged under an ,environment-led' (diverse cropping) scenario. The ,market-led' scenario is closest to short-term agricultural trajectories, but wider cultivation of biomass energy crops as modelled under the ,energy crop' scenario could occur in the medium term if energy policies are favourable. Appropriate mitigation strategies therefore need to be implemented if a continued decline in the Skylark population on lowland arable farmland is to be averted. The results provide a readily accessible visualization of the potential impacts of land-use change for policy-makers; similar techniques could be applied to visualize effects of changes arising through other drivers, including climate change. [source] Neighborhood Poverty, Racial Composition and Renal Transplant WaitlistAMERICAN JOURNAL OF TRANSPLANTATION, Issue 8 2010M. R. Saunders To date, no study has characterized the association between neighborhood poverty, racial composition and deceased donor kidney waitlist. Using the United States Renal Data System data linked to 2000 U.S. Census Data, we examined Whites (n = 152 788) and Blacks (n = 130 300) initiating dialysis between January 2000 and December 2006. Subjects' neighborhoods were divided into nine strata based on the percent of Black residents and percent poverty. Cox proportional hazards were used to determine the association between time to waitlist and neighborhood characteristics after adjusting for demographics and comorbid conditions. Individuals from poorer neighborhoods had a consistently lower likelihood of being waitlisted. This association was synergistic with neighborhood racial composition for Blacks, but not for Whites. Blacks in poor, predominantly Black neighborhoods (adjusted hazard ratio [HR] 0.57, 95% confidence intervals [CI] 0.53,0.62) were less likely to appear on transplant waitlist than those in wealthy, predominantly Black neighborhoods (HR 0.80, CI 0.67,0.96) and poor, predominantly White neighborhoods (HR 0.79, CI 0.70,0.89). All were all less likely to be waitlisted than their Black counterparts in wealthy, predominantly White or mixed neighborhoods (p < 0.05). Interventions targeted at individuals in poor and minority neighborhoods may represent an opportunity to improve equitable access to the deceased donor kidney waitlist. [source] Prostate cancer incidence among American Indian and Alaska Native men, US, 1999,2004,,§CANCER, Issue S5 2008Jeffrey A. Henderson MD Abstract BACKGROUND. American Indian and Alaska Native (AI/AN) men experience lower incidence of prostate cancer than other race/ethnic populations in the US, but racial misclassification of AI/AN men threatens the validity of these estimates. To the authors' knowledge, little is known concerning prostate-specific antigen (PSA) testing in AI/AN men. METHODS. The authors linked cancer registry data with Indian Health Service enrollment records to improve race classification. Analyses comparing cancer incidence rates and stage at diagnosis for AI/AN and non-Hispanic white (NHW) men for 6 geographic regions focused on counties known to have less race misclassification. The authors also used Behavioral Risk Factors Surveillance System data to characterize PSA testing in AI/AN men. RESULTS. Prostate cancer incidence rates were generally lower in AI/AN than in NHW men for all regions combined (rate ratio of 0.68). However, regional variation was noted among AI/AN men, with incidence rates (per 100,000 population) ranging from 65.7 in the Southwest to 174.5 on the Northern Plains. The rate of distant stage disease was somewhat higher among AI/AN (7.8) than NHW (6.2) men. Nationally, AI/AN men were less likely than NHW men to have undergone recent PSA testing (48.4% vs 58.0%), with prominent regional variation in screening rates noted. CONCLUSIONS. Prostate cancer incidence rates and the proportion of men with recent PSA testing were lower for AI/AN men than for NHW men. However, incident rates and rate of distant stage varied by region more for AI/AN than for NHW. Further research is needed among AI/AN men to evaluate strategies for better understanding the causes of the regional variation in prostate cancer incidence. Cancer 2008;113(5 suppl):1203,12. Published 2008 by the American Cancer Society. [source] Calculation of Posterior Probabilities for Bayesian Model Class Assessment and Averaging from Posterior Samples Based on Dynamic System DataCOMPUTER-AIDED CIVIL AND INFRASTRUCTURE ENGINEERING, Issue 5 2010Sai Hung Cheung Because of modeling uncertainty, a set of competing candidate model classes may be available to represent a system and it is then desirable to assess the plausibility of each model class based on system data. Bayesian model class assessment may then be used, which is based on the posterior probability of the different candidates for representing the system. If more than one model class has significant posterior probability, then Bayesian model class averaging provides a coherent mechanism to incorporate all of these model classes in making probabilistic predictions for the system response. This Bayesian model assessment and averaging requires calculation of the evidence for each model class based on the system data, which requires the evaluation of a multi-dimensional integral involving the product of the likelihood and prior defined by the model class. In this article, a general method for calculating the evidence is proposed based on using posterior samples from any Markov Chain Monte Carlo algorithm. The effectiveness of the proposed method is illustrated by Bayesian model updating and assessment using simulated earthquake data from a ten-story nonclassically damped building responding linearly and a four-story building responding inelastically. [source] Use of fresh-frozen plasma at Royal Darwin Hospital: a retrospective auditINTERNAL MEDICINE JOURNAL, Issue 9 2008S. Moylan Abstract Background:, The aim of the study was to assess the appropriateness of use of fresh-frozen plasma (FFP) at Royal Darwin Hospital against the National Health and Medical Research Council and Australian and New Zealand Society for Blood Transfusion guidelines. Methods:, A retrospective review of blood product request forms, online pathology storage system data, pathology records and clinical notes between 1 January 2006 and 31 December 2006 was carried out. The appropriateness of requests was assessed against existing guidelines. The percentage of appropriate and inappropriate FFP transfusions was obtained. Results:, Six hundred and forty-eight of 950 units (68%) of FFP were used with an appropriate indication as per National Health and Medical Research Council/Australian and New Zealand Society for Blood Transfusion guidelines. Of the remaining units, 14% (137 units) was given without a clear indication and a decision of appropriateness could not be established for 17% (165 units) because of inadequate clinical or pathology information (e.g. coagulation results). Multiple issues around prescribing practice were identified. Conclusion:, There is significant use of FFP at Royal Darwin Hospital without clear clinical indication. The employment of a transfusion nurse to monitor use of FFP (and other blood products) and provide education is aimed at improving transfusion efficiency and patient safety. [source] Energy and exergy analysis of Salihli geothermal district heating system in Manisa, TurkeyINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2005Leyla Ozgener Abstract This study deals with an energy and exergy analysis of Salihli geothermal district heating system (SGDHS) in Manisa, Turkey. In the analysis, actual system data are used to assess the district heating system performance, energy and exergy efficiencies, specific exergy index, exergetic improvement potential and exergy losses. Energy and exergy losses throughout the SGDHS are quantified and illustrated in the flow diagram. The exergy losses in the system, particularly due to the fluid flow, take place in the pumps and the heat exchanger, as well as the exergy losses of the thermal water (e.g. geothermal fluid) and the natural direct discharge of the system. As a result, the total exergy losses account for 2.22, 17.88 and 20.44%, respectively, of the total exergy input to the entire SGDHS. The overall energy and exergy efficiencies of the SGDHS components are also studied to evaluate their individual performances and determined to be 55.5 and 59.4%, respectively. Copyright © 2005 John Wiley & Sons, Ltd. [source] Wearable Data Collection System for Online Gait Stability AnalysisNEUROMODULATION, Issue 3 2004Tomaz Karcnik DSc Abstract We had shown in our previous research that the stability assessment and control are essential for generation of faster and more energy efficient functional electrical stimulation (FES) and/or crutch-assisted gait. The objective of our recent research work has been to design a wearable and portable system for gait stability analysis with online capabilities that is also applicable to crutch-assisted gait modes. The developed wearable stability assessment system for as yet only biped gait consists of foot switches and goniometers attached to the leg joints. The instantaneous static and dynamic stability is, within the wearable system, assessed from the trajectory of the estimated body center of gravity (COGHAT) and the supporting area shape/size as derived from step length and foot-floor contact state. We used motion analysis system data as reference for testing the wearable system accuracy. The wearable system was tested on five healthy subjects and one above-knee amputee. It proved to be reasonably accurate if compared to the classical, motion analysis system based method. However, additional work is required to port the system to the FES assisted and/or crutch assisted gait. [source] Attack,norm separation for detecting attack-induced quality problems on computers and networksQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 5 2007Nong Ye Abstract Cyber attacks on computer and network systems induce system quality and reliability problems, and present a significant threat to the computer and network systems that we are heavily dependent on. Cyber attack detection involves monitoring system data and detecting the attack-induced quality and reliability problems of computer and network systems caused by cyber attacks. Usually there are ongoing normal user activities on computer and network systems when an attack occurs. As a result, the observed system data may be a mixture of attack data and normal use data (norm data). We have established a novel attack,norm separation approach to cyber attack detection that includes norm data cancelation to improve the data quality as an important part of this approach. Aiming at demonstrating the importance of norm data cancelation, this paper presents a set of data modeling and analysis techniques developed to perform norm data cancelation before applying an existing technique of anomaly detection, the chi-square distance monitoring (CSDM), to residual data obtained after norm data cancelation for cyber attack detection. Specifically, a Markov chain model of norm data and an artificial neural network (ANN) of norm data cancelation are developed and tested. This set of techniques is compared with using CSDM alone for cyber attack detection. The results show a significant improvement of detection performance by CSDM with norm data cancelation over CSDM alone. Copyright © 2006 John Wiley & Sons, Ltd. [source] National rates of birth defects among hospitalized newborns,,§BIRTH DEFECTS RESEARCH, Issue 11 2006T.M. Bird Abstract BACKGROUND: The Healthcare Cost and Utilization Project (HCUP) family of hospital discharge databases offer an unprecedented opportunity to generate national estimates of newborn infants with birth defects. This report estimates national hospital admissions for newborn infants diagnosed with birth defects computed from HCUP and compares them to pooled prevalence figures computed from state birth defect surveillance systems. METHODS: HCUP-derived rates of 36 birth defects from 1997 through 2001 were compared to rates derived from pooled data reported by 26 state-based surveillance systems stratified by inclusion of elective terminations in case definitions. Rate ratios (RRs) were calculated for each birth defect by dividing the rate derived from HCUP by the rate derived from the relevant surveillance systems. RESULTS: HCUP newborn hospitalization rates for birth defects closely approximate pooled birth defect rates for surveillance systems that do not include elective terminations. HCUP rates were not significantly different for 35 of 36 defects. Overall, 20 HCUP rates were within 10% of state rates, 11 more were within 20% of state rates, and only 1 differed by more than 50%. HCUP rates compared most closely to state rates for cardiovascular (VSD RR = 0.98, ASD = 0.96, pulmonary valve atresia and stenosis = 0.92), orofacial (cleft palate RR = 1.10, cleft lip = 1.06), and genitourinary defects (obstructive genitourinary RR = 1.01, bladder exstrophy = 0.97). HCUP rates compared less favorably to rates derived from surveillance systems that included elective terminations. CONCLUSIONS: HCUP data approximate state-based surveillance system data for defects that are easily recognized in the newborn period and infrequently a cause for elective termination. HCUP data can be used to examine the impact of public health efforts on the number of infants born with birth defects as well as the cost and consequences of variations in the hospital management of birth defects. Birth Defects Research (Part A), 2006. © 2006 Wiley,Liss, Inc. [source] | ||||||||||||||||