bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiobjective Optimization including Safety of Operation Applied to a Linear Drive System
Authors: Meyer Tobias , Hölscher Christian , Menke Michael , Sextro Walter , Zimmer Detmar 
Published: November 2013

AbstractIn this contribution, we introduce a multiobjective optimization used to calculate safe optimal working points for a mechatronic system by including stochastic safety‐critical signals in an objective function.Our application example consists of a linear drive for a rail‐bound vehicle and an actuation unit. The linear drive's secondary part is fixed; the primary part is vehicle‐mounted and can be adjusted vertically to account for deviations of the height of the secondary part. A small air gap between both parts improves efficiency, but increases the risk of a collision between the two parts.Using height data of the secondary part, a trajectory for the vertical adjustment of the primary part is calculated. However, unexpected deviations necessitate a readjustment of the air gap. The probability of such unexpected height deviations can be calculated from the readjustment data. The system is equipped with sensors to measure the air gap. Assuming that the sensor noise is normally distributed, noise characteristics are determined. Using this information and the probability distribution of unexpected height deviations, the probability of a collision is determined.The sensor noise and the probability of a collision between both parts of the linear drive are included in the dynamical model of the system. Using multiobjective optimization, pareto‐optimal working points for the controller of the air gap are obtained. By selecting an appropriate working point, safe operation can be ensured. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Averaging for switched DAEs
Authors: Iannelli Luigi , Pedicini Carmen , Trenn Stephan , Vasca Francesco 
Published: November 2013

AbstractSwitched differential‐algebraic equations (switched DAEs) $E_{\sigma(t)}\dot{x}(t) = A_{\sigma(t)}x(t)$ are suitable for modeling many practical systems, e.g. electrical circuits. When the switching is periodic and of high frequency, the question arises whether the solutions of switched DAEs can be approximated by an average non‐switching system. It is well known that for a quite general class of switched ordinary differential equations (ODEs) this is the case. For switched DAEs, due the presence of the so‐called consistency projectors, it is possible that the limit of trajectories for faster and faster switching does not exist. Under certain assumptions on the consistency projectors a result concerning the averaging for switched DAEs is presented. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Sensitivity analysis of linear dynamical systems in uncertainty quantification
Authors: Pulch Roland , ter Maten E. Jan W. , Augustin Florian 
Published: November 2013

AbstractWe consider linear dynamical systems including random parameters for uncertainty quantification. A sensitivity analysis of the stochastic model is applied to the input‐output behaviour of the systems. Thus the parameters that contribute most to the variance are detected. Both intrusive and non‐intrusive methods based on the polynomial chaos yield the required sensitivity coefficients. We use this approach to analyse a test example from electrical engineering. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Performance aspects of a mixed s‐v LSFEM for the incompressible Navier‐Stokes equations with improved mass conservation
Authors: Schwarz Alexander , Schröder Jörg , Serdas Serdar , Turek Stefan , Ouazzi Abderrahim , Nickaeen Masoud 
Published: November 2013

AbstractIn the present contribution we propose an improved mixed least‐squares finite element method (LSFEM) and compare it with standard LSFEMs with respect to performance aspects. In detail, we consider an approach for Newtonian fluid flow, which is described by the incompressible Navier‐Stokes equations. The basis for the associated symmetric minimization problem is a reduced stress‐velocity (s‐v) two‐field approach, see e.g. CAI ET AL. [1] and SCHWARZ & SCHRÖDER [2]. The main idea for the proposed formulation is to add an additional equation, which yields an overconstrained first‐order system. This approach does not introduce additional unknowns, so the advantage of two variables (stresses and velocities) remains. Finally, we present a numerical example in order to show the capability of the proposed formulation. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An improved criterion for absence of eigenvalues of one‐dimensional Schrödinger operators
Authors: Seifert Christian , Vogt Hendrik 
Published: November 2013

AbstractWe study one‐dimensional Schrödinger operators with complex measures as potentials and present an improved criterion for absence of eigenvalues which involves a weak local periodicity condition. As an application we consider quasiperiodic measures as potentials. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Class of Fractional Evolutionary Equations
Authors: Picard Rainer 
Published: November 2013

AbstractA well‐posedness result for a time‐shift invariant class of evolutionary operator equations involving material laws with fractional time‐derivatives is considered and exemplified by an application to a fractional Kelvin‐Voigt type model. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Two‐scale computational homogenization of magneto‐electric composites
Authors: Keip Marc‐André , Labusch Matthias , Schröder Jörg 
Published: November 2013

AbstractThis contribution presents a two‐scale computational homogenization framework for the micro‐macro simulation of magneto‐electro‐mechanically coupled materials. Energetically consistent micro‐macro transition conditions will be derived from a generalized form of the classical Hill‐Mandel condition. A focus of the work is on the computation of effective magneto‐electric moduli which are derived on the basis of an algorithmically consistent linearization of the macroscopic field equations. The method will be applied to the homogenization of magneto‐electric composites which are composed of piezomagnetic and piezoelectric phases. The effective magneto‐electric moduli of two‐phase composites will be computed. (© 2013 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Privatizing health care in times of new public management: Investigating the role of psychological empowerment using cluster analysis
Authors: Hansen Niklas , Baraldi Stephan , Berntson Erik , Andersson Håkan 
Published: November 2013

AbstractAlthough privatization within health care is usually justified using arguments based on efficiency and productivity, the empirical investigations underpinning such arguments are few and ambiguous in their results. Presenting a new theoretical and analytical approach to this research field, we argue that psychological empowerment, reflecting individuals' intrinsic change motivation state, is a crucial prerequisite for the transformation of a nonprofit health care organization to a for‐profit one. The general aims of this study were to explore empowerment cognitions during a privatization, to relate these to a selection of key work‐related outcome variables, and to identify the effects of privatization in terms of individual level changes in empowerment after privatization. A sample of health care workers (n = 210) provided survey longitudinal data that were analyzed using cluster analysis. Eight clusters were identified at both pre‐ and postprivatization with each cluster mirroring specific empowerment patterns: Empowered, In Control, Quasi‐Empowered, Competent/Normed, Reference, Underused, Misfit, and Powerless. The clusters discriminated on positive work attitudes, mental health complaints, and turnover intentions. The analysis also revealed the complexity of privatization in that a homogenization as well as a differentiation tendency was observed, thereby implicating both socio‐structural equality and inequality effects. The results highlighted the relevance of allocating importance to health care workers' psychological empowerment during the privatization process, and of viewing such organizational transformations not as simple shifts in the state of affairs, but as nonlinear processes involving dynamic changes in individual perceptions over time.
Risk of acute myocardial infarction, stroke, or death in patients initiating olmesartan or other angiotensin receptor blockers — a cohort study using the Clinical Practice Research Datalink
Authors: Zhou Esther H. , Gelperin Kate , Levenson Mark S. , Rose Martin , Hsueh Ya‐Hui , Graham David J. 
Published: November 2013

ABSTRACTPurposeResults of two randomized trials (ROADMAP and ORIENT) suggest that high‐dose (40 mg/day) olmesartan (Olm) is associated with increased cardiovascular mortality compared to placebo in diabetic patients. We evaluated the risks of acute myocardial infarction (AMI) and death in patients initiating Olm compared with an active comparator group, other angiotensin receptor blockers (ARBs), with a focus on high‐dose and diabetic subgroups.MethodsWe conducted a cohort study with patients who initiated Olm or another ARB between 2003 and 2011, using the UK Clinical Practice Research Datalink GOLD. We included patients who had no prior ARB or angiotensin converting enzyme inhibitor exposure during the preceding 6 months. Hazard ratios (HRs) were estimated using Cox regression models with both multivariable adjustment and propensity score matching.ResultsThere were 3964 Olm and 54 653 other‐ARB initiators, respectively. Adjusted HRs comparing Olm and other‐ARBs were 1.04 (95% CI: 0.75–1.42) for AMI and 1.16 (0.95–1.42) for death, using multivariable adjustment. Comparing patients initiated with a high‐dose Olm and a high‐dose other‐ARB, HRs were 3.09 (0.94–10.13) for AMI and 2.03 (0.74–5.61) for death, using multivariable adjustment; and 4.38 (0.97–19.66) and 1.99 (0.63–6.32) for AMI and death, using propensity score matching.ConclusionsOverall, no differences in risk were observed in the main cohort analyses comparing Olm initiators with patients initiating therapy with other ARBs; however, HRs were marginally increased for all study endpoints which compared high‐dose subgroups, suggesting potential increased risk may be associated with high‐dose Olm. Published 2013. This article is a U.S. Government work and is in the public domain in the USA.
Self‐assembly of nanorod/nanoparticle mixtures in polymer brushes
Authors: Zhang Dong , Jin Yankang , Cheng Jun , Jiang Yangwei , He Linli , Zhang Linxi 
Published: November 2013

ABSTRACTThe aggregation behavior and phase separation of nanorod (NR)/nanoparticle (NP) nanoinclusions immersed in semiflexible polymer brushes (PBs) are investigated by using molecular dynamics simulations. A variety of phases are formed by varying the size ratio q = σr/σp, where σr and σp are the diameters of NR and NPs, respectively, and the attractive interactions εM between NR/NP nanoinclusions and PBs. Ordered structures of NRs surrounded by large NPs are observed for the small size ratio q, and a dispersed mixture phase appears for the moderate size ratio q at weak attractive interaction. Meanwhile, the crystallization of NRs occurs at strong attractive interaction for the large size ratio q and a main face‐centered cubic (fcc) structure combined with a small amount of hexagonal‐closed packed (hcp) structure is observed. This investigation can provide some insights into the self‐assembly of complex nanoinclusions and promise a new approach for controlling the self‐assemble behavior of NPs. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 299–309
Magnetic field‐induced morphology‐dependent resonances of a coupled composite metglas slab with a polymeric optical resonator
Authors: Ioppolo Tindaro , Rubino Edoardo 
Published: November 2013

ABSTRACTIn this article, the effect of an external magnetic field on the morphology‐dependent resonances (MDRs) of a polymeric dielectric microsphere is investigated. The microsphere is mechanically coupled to a composite polymeric Metglas slab. When an external magnetic field is applied to the slab, it elongates leading to a change in the morphology of the microsphere. This in turn leads to a shift in the excited optical resonances. Experiments are carried out to investigate the effect of an external static and harmonic magnetic field on the MDRs shift. The results show that this configuration can be used as an optical magnetic field sensor or as an optical tuning element. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014, 52, 272–275
Telomere length as a risk factor for hereditary prostate cancer
Authors: Hurwitz Lauren M. , Heaphy Christopher M. , Joshu Corinne E. , Isaacs William B. , Konishi Yuko , De Marzo Angelo M. , Isaacs Sally D. , Wiley Kathy E. , Platz Elizabeth A. , Meeker Alan K. 
Published: November 2013

AbstractBACKGROUNDTelomeres are repetitive nucleotide sequences that stabilize the ends of chromosomes. Critically short telomeres are thought to contribute to cancer development by increasing chromosomal instability. We hypothesized that shorter leukocyte telomere length, a surrogate for inherited prostate cell telomere length, would be associated with increased risk of prostate cancer in hereditary prostate cancer (HPC) families.METHODSOne hundred twelve affected and 63 unaffected men from 28 families were drawn from the Johns Hopkins HPC family database. Relative mean telomere length was measured in isolated peripheral leukocyte DNA by quantitative PCR. Conditional logistic regression was used to estimate the association between quartile of age‐adjusted telomere length and prostate cancer.RESULTSMen in the shortest quartile of telomere length did not have increased odds of prostate cancer compared to men in the other three quartiles (OR = 0.84, 95% CI: 0.32–2.20, P = 0.73). However, when the analysis was restricted to affected men with blood drawn before or within a year of diagnosis (N = 39) and all unaffected men, shorter telomere length was moderately associated with increased odds of prostate cancer (OR = 3.55, 95% CI: 0.82–15.43, P = 0.09).CONCLUSIONSThough we found no association overall, shorter leukocyte telomere length may be associated with increased odds of prostate cancer when measured in pre‐diagnostic samples. Further prospective research is warranted exploring the utility of telomere length as a prostate cancer biomarker. Prostate 74:359–364, 2014. © 2013 Wiley Periodicals, Inc.
Influence of DC bias fields on the linear/nonlinear magnetoelectric effect and the sensitivity in laminate composites
Authors: Liu Yuting , Jiao Jie , Li Lingying , Ma Jiashuai , Ren Bo , Chen Jianwei , Di Wenning , Zhao Xiangyong , Luo Haosu , Shi Ling 
Published: November 2013

AbstractThe nonlinear and linear properties in Metglas/piezofiber magnetoelectric composites under DC bias fields (Hbias) have been investigated via a frequency‐conversion technique. It was found that the major noise near the carrier frequency (fC) is caused by the driven source. Both linear ME coefficient and noise floor near fC (bandwidth of noise measurement is 10 Hz) were dependent on Hbias, while the nonlinear ME coefficient was independent. A high magnetic‐field sensitivity of 40 pT was obtained after optimizing Hbias. (© 2014 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reduction of the small gain condition for large‐scale interconnections
Authors: Dashkovskiy S. , Kosmykov M. 
Published: November 2013

SummaryThe small gain condition is sufficient for input‐to‐state stability (ISS) of interconnected systems. However, verification of the small gain condition requires large amount of computations in the case of a large size of the system. To facilitate this procedure, we aggregate the subsystems and the gains between the subsystems that belong to certain interconnection patterns (motifs) by using three heuristic rules. These rules are based on three motifs: sequentially connected nodes, nodes connected in parallel, and almost disconnected subgraphs. Aggregation of these motifs keeps the structure of the mutual influences between the subsystems in the network. Furthermore, fulfillment of the reduced small gain condition implies ISS of the large network. Thus, such reduction allows to decrease the number of computations needed to verify the small gain condition. Finally, an ISS‐Lyapunov function for the large network can be constructed using the reduced small gain condition. Applications of these rules is illustrated on an example. Copyright © 2013 John Wiley & Sons, Ltd.
Teachers’ barriers to introducing system dynamics in K‐12 STEM curriculum
Authors: Skaza Heather , Crippen Kent J. , Carroll Kristoffer R. 
Published: November 2013

AbstractSystems thinking tools and system dynamics simulations can provide a valuable means for helping students think their way around complex environmental problems. Using the results of a Web‐based survey and face‐to‐face focus group this study was designed to advance our understanding of teacher adoption of systems thinking and system dynamics modeling by documenting the perspective of a large group in an urban context tasked with a curriculum that included system dynamics simulations. Teachers identified the barriers to implementing simulation activities as both computer access and their own understanding. A test of teachers’ understanding of systems principles reveals inconsistencies in the way they interpret models, based on their previous understanding of the system. Strategies for addressing these issues include professional development that targets teacher self‐efficacy, understanding of systems and system models, as well as the provision of materials for model‐building and simulation use. Copyright © 2013 System Dynamics Society
Federgelenke
Authors: Schacht Gregor , Hoffmann Nora , Marx Steffen 
Published: November 2013

AbstractGelenkkonstruktionen aus Beton werden seit gut 100 Jahren erfolgreich im Hoch‐ und Brückenbau eingesetzt. Die von Augustin Mesnager entwickelten Federgelenke zählen dabei zu den unvollkommenen Betongelenken. Diese Gelenke sind wartungsfrei, wirtschaftlich und besitzen gegenüber unbewehrten Betongelenken nach Eugène Freyssinet aufgrund der gekreuzten Bewehrungsstähle eine erhöhte Beanspruchbarkeit gegenüber Querkräften.Der Beitrag gibt einen Überblick über die Entwicklung der Gelenkform von der ersten Idee Mesnagers bis zur erfolgreichen Anwendung im Hoch‐ und Brückenbau. Es werden die durchgeführten experimentellen Untersuchungen zum Trag‐ und Verformungsverhalten der Federgelenke vorgestellt. Die wesentlichen Erkenntnisse werden zusammengefasst und Empfehlungen für die Bemessung und Konstruktion von Betongelenken bei großen Querkrafteinwirkungen abgeleitet.Use of semi‐articulations in structural and brigde engineering.Concrete hinges have successfully been used in civil engineering constructions since over 100 years. Semi‐articulations invented by Augustin Mesnager are classified as incomplete concrete hinges. These hinges are maintenance‐free, economically and because of the crossed reinforcing bars in the hinge throat they are able to carry higher shear forces than unreinforced concrete hinges after Eugène Freyssinet.This paper gives an overview of the historical development of this type of hinge from the first idea of Mesnager till the successful use in civil engineering structures and bridges. The known experimental investigations of the bearing and deformation behavior are presented. The main findings are summarized and recommendations for the design and construction of concrete hinges under high shear forces are given.
Bewertung historischer Brückenlager
Authors: Balscheit Hagen , Else Marcus 
Published: November 2013

AbstractDer Beitrag erläutert Durchführung und Ergebnisse von Härte‐ und Verformungsmessungen an Wälzkörpern von historischen 4‐Rollen‐Wälzlagern. Diese Messungen waren Bestandteil eines von der Deutschen Forschungsgemeinschaft geförderten Vorhabens zur realitätsnahen statisch‐konstruktiven Bewertung historischer Brückenlager (LO 568/8‐1, RU 326/7‐1) [1].
Discrete element modelling of one-dimensional compression of cemented sand
Authors: de Bono J. P. , McDowell G. R. 
Published: November 2013

Abstract
It has recently been shown that the one-dimensional normal compression of sand can be modelled effectively in three-dimensions using the discrete element method, and that the slope of the compression curve (in log voids ratio–log stress space) is controlled by the size effect on average particle strength. This paper incorporates soil structure by simulating cemented sand, and the effects of inter-particle bonding (including bond strength and strength distributions) on the one-dimensional compression behaviour and evolving particle size distributions are investigated. The results show that bonding reduces particle crushing, and it is both the magnitude and distribution of bond strengths that influence the compression curve of the structured material.
Condorcet’s principle and the strong no-show paradoxes
Authors: Duddy Conal 
Published: November 2013

Abstract
We consider two no-show paradoxes, in which a voter obtains a preferable outcome by abstaining from a vote. One arises when the casting of a ballot that ranks a candidate in first place causes that candidate to lose the election, superseded by a lower-ranked candidate. The other arises when a ballot that ranks a candidate in last place causes that candidate to win, superseding a higher-ranked candidate. We show that when there are at least four candidates and when voters may express indifference, every voting rule satisfying Condorcet’s principle must generate both of these paradoxes.
Effect of habitat structural complexity on collembolan communities
Authors: Saitoh Seikoh , Fujii Saori , Takeda Hiroshi 
Published: November 2013

AbstractWe investigated soil microarthropod communities in two physically dissimilar inorganic soil materials and in a mixture of these two materials to examine the effect of the structural complexity of a habitat on microarthropod abundance and communities, teasing it out from that of nutritional factors. Mesh boxes were filled with perlite (a highly porous material), similar size of granite gravels (no pores inside), or their mixture, and placed on a forest floor. The boxes were collected after 8 or 20 months, and the microarthropods were extracted and identified to the species level, with a focus on Collembola. We also evaluated fine‐root biomass and the amount of organic matter in the boxes. It was found that the mixture of perlite and granite enhanced microarthropod abundance and root development. A partial redundancy analysis revealed that collembolan communities developed differently among the substrate materials. We also found that variation in the collembolan communities was related to fine‐root development and the abundance of other microarthropods, implying that habitat structural complexity affects collembolan communities indirectly by affecting soil food webs.