bluuebunny/crossref_metadata_2025_split huggingface dataset:
A study on cooperative tap control method for voltage profile maintenance in distribution networks with distributed generators
Authors: Nguyen Tran , Tsuji Takao , Oyama Tsutomu , Hashiguchi Takuhei , Goda Tadahiro , Shinji Takao , Tsujita Shinsuke 
Published: December 2012

AbstractThe introduction of distributed generators (DGs) that can utilize renewable energy is of prime importance to solve the energy and environmental issues. When a distribution network has a large number of DGs, voltage maintenance becomes a serious problem. To solve this problem, we had proposed the ‘voltage profile control method’ using reactive power control of DGs. However, the control is limited to continuous reactive power control so far, and tap control has not been considered. It is important that the conventional voltage control equipment such as the load ratio tap changer (LRT) or step voltage regulator (SVR) is utilized in order to enhance the control efficiency of the voltage profile control method. Therefore, in this paper, we develop a new method that can realize a cooperative work between inverters and tap control of LRT and SVR. The proposed method is tested in 8‐ and 24‐node model systems and its effectiveness is shown. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Accurate one‐terminal fault location algorithm based on the principle of short‐circuit calculation
Authors: Threevithayanon Wutthikorn , Hoonchareon Naebboon 
Published: December 2012

AbstractAn alternative method to find the line fault distance in a transmission network employing only one‐terminal measured data is presented. The proposed method applies Zbus for short‐circuit calculation to find the fault location on a transmission line without the necessity to know the fault type a priori. The well‐known drawback of the standard simple‐reactance one‐terminal algorithm, which neglects the effect of fault impedance, will be minimized by estimating the voltage drop at the fault location by employing the Zbus technique. Accuracy the proposed method is demonstrated using the short‐circuit simulation of the modified IEEE‐14 bus test system on MATLAB/Simulink and the Simpower Toolbox. Compared to the accuracy obtained from the standard one‐terminal algorithm, test results confirm substantially improved accuracy of the proposed method in all cases of the four types of fault categories: single line‐to‐ground fault; double line‐to‐ground fault; line‐to‐line fault; and balance three‐phase fault. While the accuracy has been significantly improved, especially for the case with a relatively high fault impedance, also the simplicity in the involved computation is well preserved when compared to other iterative‐based techniques. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Image‐based visual target following for a nonholonomic wheeled mobile robot with a single fixed camera
Authors: Ito Masahide , Hiratsuka Takahiro , Shibata Masaaki 
Published: December 2012

AbstractThis paper addresses the problem of visual target following for a nonholonomic wheeled mobile robot with a single fixed camera. For the problem, we propose a control scheme composed of vision‐based trajectory planning and tracking control. We present online trajectory planning based on image‐based visual servoing. The key idea is to compensate the target object motion. In particular, we focus on visual feature motion resulting from the target object motion. Tracking control to the generated trajectory can therefore achieve visual target following precisely even if the target object is moving. Our proposed scheme can be applied to, e.g. robotic systems for autonomous guard and observation. The effectiveness of the control system is evaluated experimentally. © 2012 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Resource allocation with interference mitigation in femtocellular networks
Authors: Ali Najah Abu , Ouda Mahmoud , Hassanein Hossam , Kubbar Osama 
Published: December 2012

ABSTRACTThe introduction of femtocells enabled high data rates and better indoor coverage without the need for expanding or increasing the density of cellular networks deployment or upgrading the cellular network infrastructure. Despite this direct advantage, the introduction of femtocells challenges traditional interference mechanisms because of the ad hoc and dense nature of femtocell deployment. In this paper, we propose an optimal downlink frequency assignment scheme. The proposed algorithm is modeled as a transportation problem to optimally allocate frequency subcarriers with the objective of maximizing the system capacity. The scheme can be used as a benchmark for assessing the suitability of interference mitigation schemes in femtocellular networks.Copyright © 2012 John Wiley & Sons, Ltd.
Heavy‐tailed densities
Authors: Rojo Javier 
Published: December 2012

AbstractThe concept of heavy‐ or long‐tailed densities (or distributions) has attracted much well‐deserved attention in the literature. A quick search in Google using the keywords long‐tailed statistics retrieves almost 12 million items. The concept has become a pillar of the theory of extremes, and through its connection with outlier‐prone distributions, long‐tailed distributions also play a central role in the theory of robustness.The concept of tail heaviness is by now ubiquitous, appearing in a diverse set of disciplines that includes: economics, communications, atmospheric sciences, climate modeling, social sciences, physics, modeling of complex systems, etc. Nevertheless, the precise meaning of ‘long‐’ or ‘heavy tails’ remains somewhat elusive. Thus, in a substantial portion of the early literature, long‐tailedness meant that the underlying distribution was capable of producing anomalous observations in the sense that they were ‘too far’ from the main body of observations. Implicit in these informal definitions was the notion that any distribution that behaved that way had to do so because its tails were longer than those of the normal distribution.This paper discusses tail orderings and several approaches for the classification of probability distributions according to tail heaviness. It is concluded that an approach based on the limiting behavior of the residual life function, and its corresponding characterizations based on functions of regular variation and asymptotic distribution of extreme spacings, provides the more natural and illuminating concepts of tail behavior. WIREs Comput Stat 2013, 5:30–40. doi: 10.1002/wics.1236This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Nonparametric Methods
Data: Types and Structure > Traditional Statistical Data
Quadratic programming algorithms for ensemble models
Authors: Xu Jie , Gray J. Brian 
Published: December 2012

AbstractEnsemble models, such as bagging, random forests, and boosting, have better predictive accuracy than single classifiers. These ensembles typically consist of hundreds of single classifiers, which make future predictions and model interpretation much more difficult than for single classifiers. Recently, research efforts have been directed toward improving ensembles by reducing their size while increasing or maintaining their predictive accuracy. In this article, we review recently proposed methods based on quadratic programming techniques for accomplishing these goals. WIREs Comput Stat 2013, 5:41–47. doi: 10.1002/wics.1237This article is categorized under:

Statistical Learning and Exploratory Methods of the Data Sciences > Modeling Methods
Algorithms and Computational Methods > Quadratic and Nonlinear Programming
Diagnostic tools for hierarchical linear models
Authors: Loy Adam , Hofmann Heike 
Published: December 2012

AbstractHierarchical structures are omnipresent in today's society—this is reflected in the data that we collect on all aspects of this society. Hierarchical linear models allow a representation of structural levels in a statistical modeling framework. Diagnostic tools are used to assess the quality of model estimation and explore features of the data not well described by the model. Residual and influence diagnostics are familiar tools for the classical regression model with independent observations. For hierarchical linear models, these diagnostic tools must be adjusted to reflect the dependence introduced by the nested data structure. Residual analysis now includes the assessment of distributional assumptions at each level of the model. This requires the use of level‐dependent residual quantities. Similarly, the parameter estimates may be influenced at each level of the model, requiring influence diagnostics that can pinpoint specific levels of the model, as well as specific aspects of the model. We present an overview of the diagnostic tools available for hierarchical linear models that are familiar from linear models. Additionally, we discuss the utility of the lineup protocol for residual analysis with complex models.WIREs Comput Stat2013, 5:48–61. doi: 10.1002/wics.1238This article is categorized under:Statistical Models > Bayesian ModelsStatistical and Graphical Methods of Data Analysis > Bayesian Methods and TheoryStatistical and Graphical Methods of Data Analysis > Modeling Methods and AlgorithmsStatistical and Graphical Methods of Data Analysis > Statistical Graphics and Visualization
Partial least squares algorithms and methods
Authors: Esposito Vinzi Vincenzo , Russolillo Giorgio 
Published: December 2012

AbstractPartial least squares (PLS) refers to a set of iterative algorithms based on least squares that implement a broad spectrum of both explanatory and exploratory multivariate techniques, from regression to path modeling, and from principal component to multi‐block data analysis. This article focuses on PLS regression and PLS path modeling, which are PLS approaches to regularized regression and to predictive path modeling. The computational flows and the optimization criteria of these methods are reviewed in detail, as well as the tools for the assessment and interpretation of PLS models. The most recent developments and some of the most promising on going researches are enhanced.WIREs Comput Stat2013, 5:1–19. doi: 10.1002/wics.1239This article is categorized under:Statistical Learning and Exploratory Methods of the Data Sciences > Exploratory Data AnalysisStatistical and Graphical Methods of Data Analysis > Multivariate AnalysisStatistical Models > Linear ModelsAlgorithms and Computational Methods > Least Squares
Hanging Dot Plots and identifying outliers in samples from asymmetrical populations with Hubert and Vandervieren's robust outlier rule
Authors: Bradstreet Thomas E. , Gillespie Amy , Zhang Shuping , Zhu Xingshu 
Published: December 2012

AbstractVisualizing individual data, empirical distributions, and summary statistics for small to moderate sized samples (≤ 500) is critical in early phases of drug research. We developed a customized SAS® macro, %HangingDotPlot, which displays dot plots with parametric or distribution‐free descriptive statistics and confidence intervals simultaneously on the same page for multiple groups of data. Potential statistical outliers are identified with a fence rule adapted from an adjusted box plot for skewed distributions, which incorporates the medcouple, a robust measure of skewness. WIREs Comput Stat 2013, 5:62–67. doi: 10.1002/wics.1241This article is categorized under:

Statistical and Graphical Methods of Data Analysis > Statistical Graphics and Visualization
Examples of understanding safety data using graphical methods
Authors: Anziano Richard , Gordon Robert 
Published: December 2012

AbstractCardiac and hepatic safety are important considerations in drug development. This article focuses on the examination of laboratory and electrocardiogram data using graphical approaches that enable a better understanding of the data. Useful general principles to keep in mind when developing graphics are followed by sections on cardiovascular and hepatic safety. WIREs Comput Stat 2013, 5:78–95. doi: 10.1002/wics.1243This article is categorized under:

Applications of Computational Statistics > Clinical Trials
Statistical Learning and Exploratory Methods of the Data Sciences > Exploratory Data Analysis
Data: Types and Structure > Data Preparation and Processing
Statistical and Graphical Methods of Data Analysis > Statistical Graphics and Visualization
Factors Associated with Incomplete DASH Questionnaires
Authors: Bot Arjan G. J. , Ferree Steven , Neuhaus Valentin , Ring David 
Published: December 2012

Background Missing data are unavoidable in clinical research. Older age, female gender, and fewer years of education are risk factors for missing items in a questionnaire. This study assessed the differences between patients with complete and incomplete Disabilities of the Arms, Shoulder and Hand (DASH) questionnaires in terms of demographics and psychological factors. Methods We analyzed a convenience sample of 1,204 patients enrolled in eight prospective studies. The DASH and the Pain Catastrophizing Scale were completed by all patients. The Center for Epidemiologic Studies Depression scale, Patient Health Questionnaire, Pain Anxiety Symptoms Scale, and an ordinal pain scale were completed by 745, 493, 545, and 391 patients, respectively. Bivariate analysis and binary logistic regression were used to determine risk factors for incomplete (one or more unanswered question) or invalid (more than three unanswered questions) DASH questionnaires. Results Thirty-one percent of patients did not complete all questions on the DASH. Patients with an incomplete DASH were older, had fewer years of education, and had higher levels of catastrophic thinking, depression, and pain anxiety. Age and catastrophic thinking were retained in the best logistic regression models of predictors of both incomplete and invalid DASH questionnaires. Conclusions The observation that patients who complete disability questionnaires are different from patients who do not may affect the interpretation of clinical research. Computer adaptive testing may be preferable to avoid incomplete questionnaires. Level of Evidence: Prognostic Level II.
Demographic group differences in adolescents' time attitudes
Authors: Andretta James R. , Worrell Frank C. , Mello Zena R. , Dixson Dante D. , Baik Sharon H. 
Published: December 2012

ABSTRACTIn the present study, we examined demographic differences in time attitudes in a sample of 293 adolescents. Time attitudes were measured using the Adolescent Time Attitude Scale (Mello & Worrell, 2007; Worrell, Mello, & Buhl, 2011), which assesses positive and negative attitudes toward the past, the present, and the future. Generally, African Americans and Asian Americans reported higher scores for negative time attitudes and lower scores for positive time attitudes than European Americans and Latinos, with medium sizes. Adolescents in the low socioeconomic status group reported a less favorable evaluation of their past than middle and high SES peers, but there were no meaningful differences in time attitudes by gender. Findings indicate that middle SES adolescents, high school juniors and seniors, Latinos, and European Americans had higher representation in positive time attitude clusters (i.e., Positives and Balanced) than high SES adolescents, high school freshmen and sophomores, and African Americans.
A multicenter, double‐blind, randomized, placebo‐controlled study of rifaximin for the treatment of bacterial vaginosis
Authors: Donders Gilbert G.G. , Guaschino Secondo , Peters Klaus , Tacchi Raffaella , Lauro Vittoria ,   VARIANT 1 Study Group
Published: December 2012

AbstractObjectiveTo compare efficacy and tolerability between different regimens of rifaximin vaginal tablets and a placebo for treatment of bacterial vaginosis.MethodsIn a prospective study carried out at 13 sites in 3 European countries between August 2009 and October 2010, White, non‐pregnant, premenopausal women with bacterial vaginosis were randomly assigned to receive rifaximin at 100 mg for 5 days (100 mg/5 days), 25 mg/5 days, or 100 mg/2 days, or placebo. Women were assessed at 7–10 and 28–35 days. Diagnosis and cure were based on Amsel criteria and Nugent score. Fisher exact test was used to compare cure rates.ResultsAmong 114 women recruited, 103 were evaluable for drug efficacy. Therapeutic cure rate at first follow‐up was higher in the rifaximin 25 mg/5 days (48%, P = 0.04), 100 mg/2 days (36.0%), and 100 mg/5 days (25.9%) groups than in the placebo group (19.0%). At second follow‐up, therapeutic cure rate was 28.0%, 14.8%, and 4.0% in the respective groups versus 7.7% in the placebo group. No difference in adverse events was observed.ConclusionRifaximin at 25 mg/5 days showed better therapeutic cure rates and maintenance of therapeutic cure after 1 month versus placebo. All treatment regimens were well tolerated.EudraCT number: 2009‐011826‐32.
Bericht aus der Vorstandssitzung und Mitgliederversammlung 2012
Authors: Batra Anil 
Published: December 2012

E-Mental Health Interventions for Harmful Alcohol Use: Research Methods and Questions 2.5 million yearly deaths and 4.6% of the global burden of disease are attributable to the harmful use of alcohol, according to the World Health Organization in 2011. Brief interventions have become increasingly valuable in the management of individuals with alcohol-related problems. The availability and uptake of these brief interventions is however limited. This so-called treatment gap may be narrowed through accessible, effective, and inexpensive treatment programmes. E-mental health interventions would be one promising approach for developing such treatment options, if they are shown to be effective. In this dissertation, the (cost-)effectiveness of two interventions based on cognitive behavioural therapy is subjected to research in three consecutive studies. The two interventions are a non-therapist involved Internet-based self-help programme, and a therapist led Internet therapy, based on textual-chat interaction. The aim of this dissertation is twofold. First, there is a clinical aim: to identify effective and cost-effective e-mental health interventions for harmful alcohol use. Second, there is a methodological aim: to address methodological challenges in the design, execution, and analysis of e-mental health randomized controlled trials. In the coming years, it is expected that the development and dissemination of e-mental health interventions will advance. This dissertation hopes to contribute valuably to the current knowledge base, upon which future research and interventions will build.
Quantifying the Effects of Aging Bias in Atlantic Striped Bass Stock Assessment
Authors: Liao Hongsheng , Sharov Alexei F. , Jones Cynthia M. , Nelson Gary A. 
Published: December 2012

AbstractThe effects of aging bias on stock assessment have been evaluated in many simulation studies. However, simulated data cannot be used to quantify the magnitude of aging biases in a real data set and thus their effects on an ongoing stock assessment. In this study, we validated scale and otolith aging using Striped Bass Morone saxatilis of known age collected from the Chesapeake Bay between 1997 and 2006. Otoliths provided more accurate (74% agreement) and precise (average CV = 1.9%) age estimates than scales, which overestimated the ages of young fish and underestimated the ages of old fish (22% agreement; average CV = 9.8%). Based on their accuracy, otolith ages were subsequently used to quantify aging biases in the scale ages and effects of bias in the stock assessment of Atlantic Striped Bass. We converted scale‐age to otolith‐age input using paired scale and otolith ages of Striped Bass collected by commercial fisheries in Virginia waters of the Chesapeake Bay and the mid‐Atlantic from 1999 to 2010. A statistical catch‐at‐age model was run with the scale‐ and otolith‐age input data and the results were compared. We found that aging biases from scale ages resulted in underestimates of population abundance (15%) and female spawning stock biomass (19%) and overestimates of fishing mortality in the terminal year (19%) and made strong age‐1 recruitment years appear weaker and weak ones stronger. Our study demonstrates how aging bias in a large scale‐age sample can be corrected with a relatively small sample of paired scale–otolith ages and provides fisheries management with a quantitative evaluation of aging bias and its effects on the assessment of the Atlantic Striped Bass stock.
Evaluation of Electrofishing Catch per Unit Effort for Indexing Fish Abundance in Florida Lakes
Authors: Hangsleben Matt A. , Allen Micheal S. , Gwinn Daniel C. 
Published: December 2012

AbstractElectrofishing CPUE data are commonly used to index temporal trends in abundance in fish monitoring programs, but the reliability of this index requires the assumption that the fraction of fish stock caught per unit effort (catchability, q) is relatively precise and constant through time. We evaluated how fish species, season, and lake affected electrofishing catchability in Florida lakes using a field study. We used the field study results to simulate how variable electrofishing q affects statistical power and type I error rate (i.e., the probability of detecting a difference when in fact no difference occurred). Model selection showed that electrofishing catchability varied by species, season, and lake, and submodels showed that catchability varied by lake for Largemouth Bass Micropterus salmoides and by season for Lake Chubsucker Erimyzon sucetta, and was constant across season and lake for Bluegill Lepomis macrochirus. Our results revealed that statistical power decreased and the type I error rate increased substantially if q varied through time as we observed for Largemouth Bass and Lake Chubsucker. Type I error rates were well above the expected value of 0.05, reaching as high as 0.7 for Largemouth Bass and 0.55 for Lake Chubsucker at high sample sizes. This resulted because increasing sample size improves the ability to detect real changes, but also increases the probability of detecting spurious changes due to variable q (i.e., type I error). Thus, variable catchability hinders our ability to use CPUE data to index trends in fish abundance, and monitoring programs should consider how q varies before relying on CPUE data to index fish abundance.