bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pseudo‐downsampled iterative learning control
Authors: Zhang Bin , Wang Danwei , Zhou Keliang , Ye Yongqiang , Wang Yigang 
Published: June 2007

AbstractIn this paper, a simple and effective multirate iterative learning control (ILC), referred as pseudo‐downsampled ILC, is proposed to deal with initial state error. This scheme downsamples the tracking error and input signals collected from the feedback control system before they are used in the ILC learning law. The output of the ILC is interpolated to generate the input for the next cycle. Analysis shows that the exponential decay of the tracking error can be expected and convergence condition can be ensured by downsampling. Other advantages of the proposed pseudo‐downsampled ILC include no need for a filter design and reduction of memory size and computation. Experimental results demonstrate the effectiveness of the proposed scheme. Copyright © 2007 John Wiley & Sons, Ltd.
Assessing non‐inferiority: A combination approach
Authors: Gao Ping , Ware James H. 
Published: June 2007

AbstractNon‐inferiority designs are growing in importance as a strategy for comparing new drugs with established therapies. Because it is not possible to show that a new drug and the established therapy have identical efficacy profiles, non‐inferiority trials are designed to demonstrate that the new drug is not inferior to an established drug (the ‘control’) relative to a prespecified ‘non‐inferiority margin’. No objective principle guides the choice of the non‐inferiority margin, and controversies about the margin have, in some cases, had important consequences for drug development.We argue that some of these controversies have arisen because non‐inferiority trials must achieve two objectives. They must demonstrate not only that the new drug is not inferior to the control drug by the non‐inferiority margin, but also that the new drug is superior to placebo. When the second objective is not considered explicitly, it can distort the choice of the non‐inferiority margin. Some methods designed to address both objectives through the choice of the non‐inferiority margin lead to overly stringent non‐inferiority criteria.We describe an approach to non‐inferiority analysis that combines two tests, a traditional test for non‐inferiority and a test
for superiority based on a synthetic estimate of the effect of the new treatment relative to placebo. The synthetic estimate may be ‘discounted’ to address concerns about assay inconstancy. We discuss power and sample size considerations for the proposed procedure. Copyright © 2007 John Wiley & Sons, Ltd.
Modeling heterogeneity and dependence for analysis of neuronal data
Authors: Wang Xiaofeng , Sun Jiayang , Gustafson Kenneth J. , Yue Guang H. 
Published: June 2007

AbstractIn this paper, we describe two types of neuroscience problems which challenge the typical statistical models assumed for analyzing neuronal data. This offers an opportunity for new modeling and statistical inference. In the first problem, the data are spatial neural counts which are often over‐dispersed and spatially correlated so that a standard Poisson regression model is inadequate. In the second problem, the data are averaged electroencephalograph signals recorded during muscle fatigue, where a time series AR(1) regression model cannot fully capture all the variation and correlation structure in the data. It is shown that an additional parameter has to be included in the modeling of the correlation structure and that the role of the parameter differs from one channel to the other. We propose appropriate generalized models for these data, develop statistical procedures under the generalized models, and apply these procedures to the real data that motivated this paper. The effect of mis‐specification of a correlation structure is also investigated. Copyright © 2007 John Wiley & Sons, Ltd.
Flexible two‐stage design with sample size reassessment for survival trials
Authors: Desseaux K. , Porcher R. 
Published: June 2007

AbstractFlexible trials with adaptive design modification at interim analyses have been recently proposed as an answer to cope with some limitations of traditional designs for phase III trials. Actually, the sample size and duration of fixed design trials strongly depend on the determination, prior to the study, of key parameters such as the expected treatment effect and the event rates. A misspecification of these parameters may result in an underpowered or overpowered trial. In the flexible framework, the remainder of a design can be modified at an interim analysis, while preserving the initially specified global error rates. In this work, we present a flexible design with sample size re‐evaluation for survival trials and study its properties in practical settings. The results show that, if parameters are initially misspecified, the proposed method allows an improved power control with a reasonable increase in sample size, if any. Practical guidelines concerning the choice of the trial parameters are also given. Copyright © 2007 John Wiley & Sons, Ltd.
The impact of racial diversity on intermediate and long‐term performance: The moderating role of environmental context
Authors: Richard Orlando C. , Murthi B. P. S , Ismail Kiran 
Published: June 2007

AbstractWe conduct a firm‐level, 6‐year longitudinal analysis on the impact that racial diversity in human resources has on financial performance. When considering short‐term performance outcomes, we predict a curvilinear relationship between diversity and performance (i.e., firm productivity). Although we find evidence of a U‐shaped relationship between racial diversity and productivity, the relationship is stronger in service‐oriented relative to manufacturing‐oriented industries and in more stable vs. volatile environments. For longer‐term profitability, we propose and find support for more of a positive linear relationship between diversity and performance (i.e., Tobin's q) than a nonlinear one. This linear effect is stronger and more positive in munificent compared to resource‐scare environments. Thus, we aid in reconciling existing, often contradictory, studies by demonstrating the potential short‐term vs. long‐term impact of racial diversity on performance. We offer implications for future research on diversity considering the current and projected demographic landscape. Copyright © 2007 John Wiley & Sons, Ltd.
Approximate analysis of symmetrical structures consisting of different types of bents
Authors: Georgoussis George K. 
Published: June 2007

AbstractAn approximate analysis is presented for calculating the deflections of individual cantilever bents, under lateral loading, as a sum of deflections of two complementary subsystems: a flexural and a shear–flexure subsystem. The analysis accounts for axial deformations in the vertical members of bents, since it is based on the continuum approach as is used in the coupled wall theory, and is also applicable to other types of cantilever bents used in concrete structures, such as rigid frames and wall frame assemblies. The fact that the deflection equation of a cantilever bent may be decomposed into two components makes possible the development of an approximate method for estimating the deflections of uniform plan‐symmetrical buildings composed of different structural bents. The method provides a rapid estimate of deflections and load distribution in such multi‐bent structures and therefore it is appropriate for preliminary structural design. At this stage, it is desirable for the practising engineer to have a quick estimate of the maximum response, even if the actual sizes of the structural elements are not yet known and only assumptions can be made about the relative stiffnesses of the major structural elements. The proposed analysis, as based on distributed parameter formulations, has the advantage of providing a deep insight into the structural behaviour of high‐rise structures. Its accuracy is evaluated by comparing the approximate results with those obtained by stiffness matrix analyses. Copyright © 2007 John Wiley & Sons, Ltd.
Variability of seismic demands according to different sets of earthquake ground motions
Authors: Han Sang Whan , Kim Eung Soo , Hwang Soo Min 
Published: June 2007

AbstractIt is a challenging task to predict seismic demands for earthquake resistant design, particularly for tall buildings. In current seismic design provisions, seismic demands are expressed as a design base shear of which the key components are linear elastic design response spectra, force reduction factor (‘R factor’), and building weight. For tall buildings, response spectrum analysis or response history analysis is recommended in current design provisions. In recent years, new methods for predicting seismic demands have been developed, such as the capacity spectrum method (CSM) and displacement coefficient method. This study investigates the effect of different earthquake ground motion (EQGM) sets on seismic demands. Key components of the base shear and performance points in the CSM are considered as the seismic demands to be tested. For this purpose three EQGM sets are collected independently at rock sites. This study found that seismic demands can vary significantly according to different EQGM sets even though those sets were obtained at sites with similar soil conditions. This study also attempts to provide a criterion for reducing the variability in seismic demands according to different EQGM sets. Copyright © 2007 John Wiley & Sons, Ltd.
Application of GPS to monitoring of wind‐induced responses of high‐rise buildings
Authors: Park Hyo Seon , Sohn Hong Gyoo , Kim Ill Soo , Park Jae Hwan 
Published: June 2007

AbstractA new monitoring system using GPS is introduced to measure wind‐induced responses of high‐rise buildings. In this paper, wind‐induced responses of a long‐period structure include relative lateral displacements, acceleration records, and torsional displacements at the top of a building. After comparing responses of a test model measured by GPS with responses obtained by the most commonly used laser displacement meters and accelerometers, the wind‐induced responses of a 66‐story high‐rise building subject to the yellow dust storm were measured by the GPS‐based monitoring system. Based on the field measurement, it is concluded that the complete motion history of a high‐rise building can be monitored by GPS. Copyright © 2007 John Wiley & Sons, Ltd.
Semi‐active control for eccentric structures with MR damper based on hybrid intelligent algorithm
Authors: Li Hong‐Nan , Chang Zhi‐Guo 
Published: June 2007

AbstractIn this paper, an application of the hybrid intelligent control algorithm to semi‐active control of the magnetorheological (MR) damper is presented for engineering structures. The control signal is optimized directly by the µGA approach to obtain the numerical relation between the control signal and the system output. This relation is then stored in the weight value of a trained artificial neural network, which can be available for another structure subjected to other seismic inputs. The results of a numerical example indicate that the semi‐active control of the MR damper based on the hybrid algorithm can efficiently reduce the structural responses induced by an earthquake. Copyright © 2007 John Wiley & Sons, Ltd.
Vibration characteristics of tall buildings braced by shear walls and thin‐walled open‐section structures
Authors: Meftah Sid Ahmed , Tounsi Abdelouahed 
Published: June 2007

AbstractAn analytical method is presented for the three‐dimensional frequency analysis of buildings braced by shear walls and thin‐walled open‐section structures. Owing to the asymmetry of the structure, the centre of gravity and the centre of flexural rigidity of the floor plan do not coincide, and hence the flexural vibration in two mutually perpendicular directions and the warping torsional vibrations are all coupled. Based on the continuum approach and D'Alembert's principle, the governing differential equation of free vibration and its corresponding eigenvalue problem for asymmetric shear walls and thin‐walled open‐section structures are derived. Based on the theory of differential equations, an analytical method of solution is proposed to solve the eigenvalue problem and a general solution is derived for determining the natural frequencies of the structures. Results obtained from the proposed method for the example structure show good agreement with those of finite element analysis. It is also shown that the proposed analysis is efficient and accurate enough to be used both at the concept design stage and for final analysis. Copyright © 2007 John Wiley & Sons, Ltd.
Comparative study of structural material quantities of high‐rise residential buildings
Authors: Kim Sang Bum , Lee Young Hak , Scanlon Andrew 
Published: June 2007

AbstractA major factor in the selection of the structural system for a high‐rise building is the initial construction cost of candidate structural systems. In Korea, composite steel and concrete construction, and cast‐in‐place concrete flat plate construction are the most commonly used structural systems. However, there is a lack of data related to the relative construction costs of these two structure types. This paper compares material quantities for representative building models up to 80 stories in height using both types of structural system. Based on a typical floor plan, six models are developed and the buildings are designed for gravity and lateral loading. Quantities of materials for each model are calculated and compared. The information presented can be used with appropriate cost data to compare construction costs for the two structural system types. Copyright © 2007 John Wiley & Sons, Ltd.
Upscaling of variational inequalities arising in nonlinear problems with unilateral constraints
Authors: Timofte C. 
Published: June 2007

AbstractThe aim of this paper is to study the asymptotic behavior of the solution of a nonlinear variational inequality in periodically perforated media. The domain is considered to be a fixed bounded open subset of ℝn, in which identical and periodically distributed perforations of size ϵ are made. The asymptotic behavior of the solution of such a problem is governed by an obstacle problem, associated to the homogenization of a periodic heterogeneous and perforated medium.
Optimal control of the free boundary in a two‐phase Stefan problem with flow driven by convection
Authors: Hinze M. , Ziegenbalg S. 
Published: June 2007

AbstractWe present an optimal control approach for the solidification process of a melt in a container. The process is described by a two phase Stefan problem including flow driven by convection and Lorentz forces. The free boundary (interface between the two phases) is modelled as a graph. We control the evolution of the free boundary using the temperature on the container wall and/or the Lorentz forces. The control goal consists in tracking a prescribed evolution of the free boundary. We achieve this goal by minimizing a appropriate cost functional. The resulting minimization problem is solved numerically by a steepest descent method with step size control, where the gradient of the cost functional is expressed in terms of the adjoint variables. Several numerical examples are presented which illustrate the performance of the method.
Cytoskeleton as a potential target in the neuropathology of maple syrup urine disease: Insight from animal studies
Authors: Pessoa‐Pureur R. , Wajner M. 
Published: June 2007

SummaryIn this short review we provide evidence that the branched‐chain keto acids accumulating in the neurometabolic disorder maple syrup urine disease disturb rat cerebral cytoskeleton in a developmentally regulated manner. Alterations of protein phosphorylation leading to brain cytoskeletal misregulation and neural cell death caused by these metabolites are associated with energy deprivation, oxidative stress and excitotoxicity that may ultimately disrupt normal cell function and viability.
Cardiac abnormalities in adults with the attenuated form of mucopolysaccharidosis type I
Authors: Soliman O. I. I. , Timmermans R. G. M. , Nemes A. , Vletter W. B. , Wilson J. H. P. , ten Cate F. J. , Geleijnse M. L. 
Published: June 2007

SummaryBackground:Cardiac involvement in mucopolysaccharidosis type I (MPS I) has been studied primarily in its most severe forms. Cardiac involvement, particularly left ventricular (LV) systolic and diastolic function, in the attenuated form of MPS I is less well known.Methods:Cardiac function was prospectively investigated in 9 adult patients with the attenuated form of MPS I. All patients underwent 12‐lead electrocardiography, 24 h Holter monitoring and two‐dimensional echocardiography including tissue Doppler imaging (TDI). Eighteen age‐ and sex‐matched healthy volunteers served as a control group.Results:Aortic, mitral and tricuspid valve thickening was seen in, respectively, 5 (56%), 4 (44%) and 2 (22%) patients. Moderate mitral valve stenosis was seen in 1 patient and moderate aortic stenosis in 2 patients. All patients had mild‐to‐moderate aortic and mitral valve regurgitation and 6 patients (67%) had mild‐to‐moderate tricuspid valve regurgitation. Despite normal LV dimensions, ejection fraction and mass index, MPS patients had lower mean systolic mitral annular velocities (6.1±0.6 vs 9.1±1.4 cm/s, p<0.01) compared to normal control subjects. Similarly, mean early diastolic mitral annular velocities were lower in MPS patients (7.8;±0.9 vs 13.3±3.3 cm/s, p<0.01).Conclusion:MPS I patients with the attenuated phenotype have not only valvular abnormalities but also LV diastolic and systolic abnormalities.
First ISNS Reference Preparation for Neonatal Screening for thyrotropin, phenylalanine and 17α‐hydroxyprogesterone in blood spots
Authors: Elvers L. H. , Loeber J. G. , Dhondt J.‐L. , Fukushi M. , Hannon W. H. , Torresani T. , Webster D. 
Published: June 2007

SummaryBackgroundNeonatal screening for congenital disorders like phenylketonuria (PKU), congenital hypothyroidism (CH) and congenital adrenal hyperplasia (CAH) is generally performed in dried blood spots on filter paper. The analytes of interest for testing for PKU, CH and CAH are phenylalanine, thyrotropin (TSH) and 17α‐hydroxyprogesterone (17OHP), respectively. The International Society for Neonatal Screening (ISNS) decided to prepare a combined reference preparation for the three analytes on filter paper Schleicher & Schuell #903, Whatman BFC180 and Toyo Roshi 545. This ‘First ISNS Reference Preparation for Neonatal Screening for TSH, phenylalanine and 17OHP in blood spots’ (1st ISNS‐RPNS) has been prepared by the RIVM (Bilthoven).MethodThe number of filter paper cards prepared, each with two sets of six blood spot calibrators, was 480, 42 and 69 for Schleicher & Schuell #903, Whatman BFC180 and Toyo Roshi 545, respectively. The volume of blood dispensed was 50 μl. The range of concentrations for TSH was 1–121 mIU/L blood, for phenylalanine 65–865 μmol/L blood and for 17OHP 2.2–302 nmol/L blood.ResultsThe linearity of the blood spot calibrators and the homogeneity of the batch (only tested for Schleicher & Schuell) were good. The differences between the three filter papers were small: i.e. the potency of the ISNS‐RPNS on Whatman and Toyo Roshi in terms of Schleicher & Schuell was between 0.98 and 1.09 for the three analytes.ConclusionThe 1st ISNS‐RPNS for TSH, phenylalanine and 17OHP can be said to be suitable as formal reference preparation and as a source for (re)calibrating kit calibrators.
Primary Biodegradation of Commercial Fatty‐Alcohol Ethoxylate Surfactants: Characteristic Parameters
Authors: Jurado E. , Fernández‐Serrano M. , Núñez‐Olea J. , Lechuga M. 
Published: June 2007

AbstractThis paper concerns the primary biodegradation of different commercial fatty‐alcohol ethoxylate surfactants (FAEs), applying the OECD 301 E test for ready biodegradability. Changes were made both in the carbon‐chain length of the surfactants as well as in the number of units of ethylene oxide (EO) in its molecule. The biodegradation were monitored, analysing the colony‐forming units (CFU) formed during this process. From the biodegradation profiles drawn for the FAEs, parameters characteristic of the biodegradation process were defined: latency time (tL), biodegradability at 50 h of assay (B), half‐life (t1/2), mean biodegradation rate until reaching biodegradability of 85% (VM), and the residual concentration of the surfactant (SR). The analysis of these parameters enabled the establishment of the influence of surfactant concentration and structure during the biodegradation process. The increase in the surfactant concentration lowered the rate of the biodegradation process and the biodegradability of the surfactant in addition to the half‐life and residual concentration of the surfactant. The mean biodegradation rate,VM, for fatty‐alcohol ethoxylates increased with the number of EO units and molecular weight of the surfactant. At low initial test concentrations (less than 25 mg/L), the concentration of the residual surfactant rapidly diminished with biodegradation time. For higher concentrations, after an adaptation period of the microorganisms, the surfactant concentration declined exponentially and the biodegradation rate became far slower for all the surfactants. The parameters characteristic of the growth curves: specific growth‐rate,k, and the yield of biomass production per gram of surfactant,Yap, made possible the quantification and corroboration of the results during the biodegradation process.
Effects of In Ovo Administration of DHEA on Lipid Metabolism and Hepatic Lipogenetic Genes Expression in Broiler Chickens During Embryonic Development
Authors: Zhao Sumei , Ma Haitian , Zou Sixiang , Chen Weihua 
Published: June 2007

AbstractIn order to study the mechanism of DHEA (Dehydroepiandrosterone) in reducing fat in broiler chickens during embryonic development, fertilized eggs were administrated with DHEA before incubation and its effect on lipid metabolism and expression of hepatic lipogenetic genes was investigated. The mRNA levels of acetyl CoA carboxylase (ACC), fatty acid synthase (FAS), malic enzyme (ME), apolipoprotein B100 (apoB100) and sterol regulator element binding protein‐1c (SREBP‐1c) were determined using real time quantitative PCR. Samples of livers were collected from the chickens on days 9, 14, and 19 of embryonic development as well as at hatching. Blood samples were extracted on days 14, 19 of incubation and at hatching. The results showed that DHEA decreased the concentration of triacyglycerol in the blood and the content in liver, and the mRNA levels of ACC, FAS, ME, SREBP‐1c and apoB. This suggested that DHEA decreased the expression of hepatic lipogenetic genes and suppressed triglycerols transport, by which it reduced the deposition of fat in adipose tissue in broiler chickens during embryonic development and hatching.