bluuebunny/crossref_metadata_2025 huggingface dataset:
Using Swap‐Based Search Trees to obtain Solutions for Resource Constrained Project Scheduling Problems
Authors: Bügler Maximilian , Borrmann André
Published: December 2014

The high level of complexity in modern construction projects causes the problem of scheduling the involved tasks under precedence and resource constraints to be a great challenge. Additionally applications on real construction sites require non linear and non continuous constraints and objective functions. In order to optimize large scale construction sites in practice, this paper proposes a new optimization approach based on creating search trees from swapping and delaying tasks. The convergence of the proposed algorithm is analyzed and its complexity is compared to other available algorithms. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
On the Convergence Analysis of a Two‐Step Modification of the Gauss‐Newton Method
Authors: Iakymchuk Roman , Shakhno Stepan
Published: December 2014

We investigate the convergence of a two‐step modification of the Gauss‐Newton method applying the generalized Lipschitz condition for the first and second order derivatives. The convergence order as well as the convergence radius of the method are studied and the uniqueness ball of solution of the nonlinear least squares problem is examined. Finally, we carry out numerical experiments on a set of well‐known test problems. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal Parameter Tuning for Multiclass Support Vector Machines in Machinery Health State Estimation
Authors: Kimotho James Kuria , Sextro Walter
Published: December 2014

The increasing demand for high reliability, safety and availability of technical systems calls for innovative maintenance strategies. The use of prognostic health management (PHM) approach where maintenance action is taken based on current and future health state of a component or system is rapidly gaining popularity in the maintenance industry. Multiclass support vector machines (MC‐SVM) has been identified as a promising algorithm in PHM applications due to its high classification accuracy. However, it requires parameter tuning for each application, with the objective of minimizing the classification error. This is a single objective optimization problem which requires the use of optimization algorithms that are capable of exhaustively searching for the global optimum parameters. This work proposes the use of hybrid differential evolution (DE) and particle swarm optimization (PSO) in optimally tuning the MC‐SVM parameters. DE identifies the search limit of the parameters while PSO finds the global optimum within the search limit. The feasibility of the approach is verified using bearing run‐to‐failure data and the results show that the proposed method significantly increases health state classification accuracy. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A Cache‐Aware Implementation of the Spectral Divide‐and‐Conquer Approach for the Non‐Symmetric Generalized Eigenvalue Problem
Authors: Benner Peter , Köhler Martin , Saak Jens
Published: December 2014

We propose a new implementation of the sign function based spectral divide‐and‐conquer method for the generalized non‐symmetric eigenvalue problem. The basic idea is to use the generalized matrix sign function to split the spectrum and the corresponding deflating subspaces and to build a recursive scheme on top of this. The method focuses on an extensive usage of scalable level 3 BLAS operations in order to achieve a good performance on modern computer architectures which makes it computationally superior to current implementations of the classical QZ algorithm. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A numerical example showing that deflations based on rotation leads to higher relative accuracy in QR algorithm
Authors: Mach Thomas , Vandebril Raf
Published: December 2014

We present a numerical example illustrating that the deflation procedure in Francis's implicitly shifted QR algorithm can be improved by a deflation criteria based on the QR decomposition of the upper Hessenberg matrix. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Combined State and Parameter Reduction
Authors: Himpe Christian , Ohlberger Mario
Published: December 2014

This work demonstrates combined state and parameter space reduction for large‐scale control systems. Two methods for combined reduction are briefly introduced and tested on two different models for brain connectivity. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Viscoelasticity at Large Strain Deformations
Authors: Meyer Arnd , Schmidt Hansjörg
Published: December 2014

We present a theory of viscoelasticity at large strain deformations. Starting from a non‐linear weak formulation, we examine the viscoelastic stress‐strain relation and the linearised system of equations. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Domain decomposition methods for nonlinear transmission conditions
Authors: Gsell Matthias A. F. , Steinbach Olaf
Published: December 2014

We consider the transformation of quasilinear partial differential equations to a coupled system of linear equations, but with nonlinear transmission conditions on the interfaces. After deriving a variational formulation, we will discuss Mortar finite element discretization strategies and present a numerical example. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Actual time integration methods for elastic wave propagation analysis
Authors: Asmus Andreas , Lammering Rolf
Published: December 2014

For the simulation of the interaction of elastic waves in CFRP plates with inhomogeneities and defects the spectral finite element method (SEM) is under investigation. The SEM uses high‐order shape functions which are composed of Lagrange polynomials with nodes at the Gauss‐Lobatto quadrature (GLq) points. In this way we obtain a diagonal mass matrix which makes an explicit time scheme more efficient. In this paper we analyse how actual time integration methods perform in combination with the SEM. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Preconditioned defect corrected averaging for parabolic PDEs
Authors: Klöppel Michael , Naumann Andreas , Wensch Jörg
Published: December 2014

Modelling physical systems with fast moving components leads to PDEs with highly oscillatory sources. Often, the time scale of the oscillation is much below the scale of the interesting variables. Time integrators must follow the scale of the fast motion, leading to long simulation times. For mechanical systems, methods like heterogeneous multiscaling and stroboscopic averaging are quite satisfactory. In case of semidiscretized PDEs, their advantage is limited. Here, we derive a smooth source term which generates a solution that coincides with the solution of the oscillatory system in stroboscopic points. The derivation involves the solution of a linear system with the solution operator of the PDE being the linear operator. Several preconditioners are developed and compared for those systems. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Residual‐based a posteriori error control for Space‐time finite element approximations of parabolic optimal control problems
Authors: Gong Wei , Hinze Michael , Zhou Zhaojie
Published: December 2014

In this paper we investigate a space‐time finite element approximation of parabolic optimal control problems. The first order optimality conditions are transformed into an elliptic equation of fourth order in space and second order in time involving only the state or the adjoint state in the space‐time domain. We derive a priori and a posteriori error estimates for the time discretization of the state and the adjoint state. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Optimal Control of Large Deformation Elasticity by Fiber Tension
Authors: Günnel Andreas , Herzog Roland
Published: December 2014

Object of our interest is an elastic body Ω ⊂ ℝ3 which we can deform by applying a tension along certain given short fibers inside the body. The deformation of the body is desribed by a hyperelastic model with polyconvex energy density and a special energy functional for the tension along the fibers. We seek to apply (possibly large) deformations to the body so that a desired shape is obtained. To this end, we formulate an optimal control problem for the fiber tension field. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Proper orthogonal decomposition in sparse optimal control of some reaction diffusion equations using model predictive control
Authors: Ryll Christopher , Tröltzsch Fredi
Published: December 2014

We investigate optimal sparse control problems for reaction diffusion equations with non‐monotonous cubic non‐linearities. In particular, we consider the Schlöl equation as well as the FitzHugh‐Nagumo system. In these models, the solutions form pattern of traveling wave fronts or spiral waves. To control them turns out to be very challenging and computational difficult. The needed computational times are enormous. The use of sparse optimal control techniques was surprisingly very helpful. On the one hand the optimal control becomes sparse and on the other hand we achieve our control goals with satisfying accuracy for much less computational time then before. Trying to decrease it even more by POD model reduction does not work sufficiently well since too many POD modes are needed to approximate the solutions satisfactorily. Our second approach is the application of model predictive controls. This technique performs very well for the control aim of following a desired trajectory. An additional use of POD model reduction for each ‐ now very small ‐ time horizon yields even better results in computational time with a marginal loss of precession. This result holds for optimal controls as well as for optimal sparse controls. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Real‐time Model Predictive Control of a Pendulum
Authors: Schnelle Fabian , Eberhard Peter
Published: December 2014

In this work, a model predictive approach is applied on a mechanical system with a view on a real‐time capable implementation. The mechanical system is represented by a pendulum, which consists of a sphere at the end of a long, thin rod. The rod is mounted on gimbals on a cross table, which can be moved by two DC motors. The control objective is trajectory tracking of the sphere, which can be realized by the control of these motors. In this work, linear model predictive control techniques are designed for the pendulum and are simulatively compared with regard to an accurate trajectory tracking and a real‐time capable algorithm. A linear time‐invariant approach is implemented on the experiment. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Trajectory generation with rich information content
Authors: Mayr Simon , Grabmair Gernot
Published: December 2014

Often, trajectories for mechanical systems are generated solving some optimization problem. Common approaches include time‐optimal, energy optimal, etc., motion profiles. In order to decrease mechanical wear of real plants this profiles provide, e.g., a smooth movement (rest‐to‐rest) in accordance with restrictions in jerk, acceleration and velocity. There exists a number of methods, to calculate for a given trajectory the plant feed forward action and to design stabilizing controllers. In case of parameter uncertainty the control law often exhibits some adaptive part. Unfortunately, smooth trajectories tend to contain insufficient excitation for adaption and/or identification. Therefore, we propose to consider some measure for the information content concerning some unknown parameters in the trajectory optimization problem. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Discrete mechanics and mixed integer optimal control of dynamical systems
Authors: Ringkamp Maik , Ober‐Blöbaum Sina , Leyendecker Sigrid
Published: December 2014

Mixed integer optimal control problems are a generalization of ordinary optimal control problems that include additional integer valued control functions. The integer control functions are used to switch instantaneously from one system to another. We use a time transformation (similar as in [1]) to get rid of the integer valued functions. This allows to apply gradient based optimization methods to approximate the mixed integer optimal control problem. The time transformation from [1] is adapted such that problems with distinct state domains for each system can be solved and it is combined with the direct discretization method DMOC [2,3] (Discrete Mechanics and Optimal Control) to approximate trajectories of the underlying optimal control problems. Our approach is illustrated with the help of a first example, the hybrid mass oscillator. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Variational integrators for nonlinear electric circuits
Authors: Ober‐Blöbaum Sina , Lindhorst Henning
Published: December 2014

The variational framework for linear electric circuits introduced in [1] is extended to general nonlinear circuits. Based on a constrained Lagrangian formulation that takes the basic circuit laws into account the equations of motion of a nonlinear electric circuit are derived. The resulting differential‐algebraic system can be reduced by performing the variational principle on a reduced space and regularity conditions for the reduced Lagrangian are presented. A variational integrator for the structure‐preserving simulation of nonlinear electric circuits is derived and demonstrated by numerical examples. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Solution of Descriptor Lur'e Equations via Even Matrix Pencils
Authors: Reis Timo , Voigt Matthias
Published: December 2014

Descriptor Lur’e equations are an important tool for the solution of linear‐quadratic optimal control problems for differential‐algebraic systems. In this article we discuss how one can construct all solutions of these equations by the deflating subspaces of associated even matrix pencils. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Efficient Observer Design for Multirate Sampled‐Data Systems
Authors: Voigt Thorsten , Konigorski Ulrich
Published: December 2014

This contribution deals with the observer design for linear multirate sampled systems. The proposed algorithm is fea‐tured by a time‐invariant modelling approach. It is shown that a multirate state observer can be derived by gradually building up the observer gain matrix by means of optimization based design methods in combination with a pole placement observer design. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Open‐loop control of parameter‐dependent discrete‐time systems
Authors: Scherlein Barbara , Schönlein Michael , Helmke Uwe
Published: December 2014

We consider parameter‐dependent linear time‐invariant discrete‐time single input systems, where the system matrix and the input vector are assumed to depend continuously on a parameter varying over a compact interval. We face the problem of steering the zero state simultaneously arbitrarily close towards a given continuous family of desired terminal states with a finite parameter independent open‐loop input sequence. Starting from existing sufficient conditions, which include simplicity of the eigenvalues of the system matrices, we examine the case of multiple eigenvalues. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Parallel time integration with multigrid
Authors: Falgout Robert , Friedhoff Stephanie , Kolev Tzanio , MacLachlan Scott , Schroder Jacob B.
Published: December 2014

With current trends in computer architectures leading towards systems with more, but not faster, processors, faster time‐to‐solution must come from greater parallelism. We present a family of truly multilevel approaches to parallel time integration based on multigrid reduction (MGR) principles. The resulting multigrid‐reduction‐in‐time (MGRIT) algorithms are non‐intrusive approaches, which directly use an existing time propagator and, thus, can easily exploit substantially more computational resources then standard sequential time‐stepping. Furthermore, we demonstrate that MGRIT offers excellent strong and weak parallel scaling up to thousands of processors for solving diffusion equations in two and three space dimensions. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Implementing a discontinuous Galerkin method for the compressible, inviscid Euler equations in the DUNE framework
Authors: Gallego‐Valencia Juan Pablo , Löbbert Johannes , Müthing Steffen , Bastian Peter , Klingenberg Christian , Xia Yinhua
Published: December 2014

A discontinuous Galerkin scheme was implemented in the DUNE framework to solve the compressible, inviscid Euler equations in a multi‐dimensional Cartesian grid. It uses a HLLC Riemann solver for the numerical fluxes in the interfaces, a total variation bounded limiter to handle discontinuities, a positivity preserving limiter for near vacuum conditions, and adaptive mesh refinement (AMR). (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
An adaptive moving mesh approach for hyperbolic conservation laws on time‐dependent domains
Authors: Schiessl Stefan , Marheineke Nicole , Arne Walter , Wegener Raimund
Published: December 2014

The general idea of moving mesh approaches is to improve the approximation quality and the numerical performance by redistributing a fixed number of discretization points. This is called rrefinement. The classical approaches are applied to partial differential equations on fixed domains. An extension to time‐dependent (expanding) domains is presented. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Reducing of birefringence of [111]‐cut crystal rod using side‐pumping and suitable crystal rotation
Authors: Graupeter Thomas , Pflaum Christoph
Published: December 2014

The beam quality and output power of high power solid‐state lasers is influenced by birefringence. Inhomogeneous distribution of the thermal field inside the laser crystal rod occurs due to non‐uniform absorption of the pump light inside the crystal and a heat sink only at boundaries. Due to the photoelastic effect, this distribution leads to inhomogeneous thermal strains and birefringence inside the rod. Plane stress and plane strain assumptions for an axially symmetric pumped crystal have been used formerly for analytical models for calculating the birefringence. This model leads in case of an [111]‐cut crystal to an axially symmetric birefringence pattern. However, the shear strains in the axial‐radial plane are neglected in this former models using plane stress and plane strain assumptions. This shear strains are taken into account by full 3D numerical calculations. A threefold symmetry pattern due to the anisotropic behaviour of the photoelastic tensor, which is contradictory to the ideal use of a radial or azimuthal polarized beam, is shown by results of the birefringence simulation. A laser rod pumped at three sides with threefold symmetry is analysed in order to reduce the effect of birefringence. In this case the absorption is not axially symmetric anymore. Within the crystal in regions where pumping is stronger, the pump light absorption and consequently the temperature, the strains and birefringence are higher. The degree of three‐fold symmetry of birefringence will be reduced, if the region having a low birefringence due to the photoelastic effect is more strongly pumped than the rest of domain. This means the birefringence is affected by the rotation of crystal around its [111]‐axis. By an optimal rotation with respect to the edges of the crystal, smallest birefringence can be obtained. For generating radial or azimuthal polarizations, the output beam of this laser device is therefore more suitable. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Error estimates for the Ginzburg‐Landau approximation: an overview and recent results
Authors: Schneider Guido , Zimmermann Dominik
Published: December 2014

We consider quasilinear parabolic systems posed on the real line with a spatially homogeneous ground state which becomes unstable via a Hopf‐, Turing‐, or Turing‐Hopf instability. Then close to the first instability via multiple scaling analysis a Ginzburg‐Landau equation can be derived in order to describe bifurcating solutions which are slow modulations in time and space of the most unstable modes. We give an overview about the mathematical justification and explain recent error estimates. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Convergence of 2D‐Schrödinger operators with local scaled short‐range interactions to a Hamiltonian with infinitely many δ‐point interactions
Authors: Behrndt Jussi , Holzmann Markus , Lotoreichik Vladimir
Published: December 2014

We prove, that a Hamiltonian with infinitely many δ‐point interactions in the plane can be approximated in the norm resolvent sense by a family of Schrödinger operators with regular, local scaled short‐range potentials. Similar well known results from the 1D and the 3D case are complemented thereby. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Kernel estimates for perturbations of positive semigroups
Authors: Seifert Christian
Published: December 2014

Given a positive C0‐semigroup T0 on L2(Ω, m) with a kernel k0, where (Ω, m) is a σ‐finite measure space, we study a suitably perturbed semigroup T and prove existence of a kernel k for T and an estimate of the k in terms of k0. In this way we extend a heat kernel estimate proven by Barlow, Grigor’yan and Kumagai [4] for Dirichlet forms perturbed by jump processes. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Investigation of potential flow using the soap film analogy – a historical review
Authors: Heitkam Sascha , Ihlenfeld Horst , Fröhlich Jochen
Published: December 2014

The soap film analogy is a tool for analysing potential flow in complex geometries. It has been used around 1960 in Dresden to investigate the flow in high‐pressure turbine cascades. The present paper briefly reviews the technique and reports on the comparison between historical results, achieved with the soap film analogy, and numerical simulations. It illustrates the capabilities of the method and the historical progress made since then. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
A one shot method for divertor target shape optimization
Authors: Dekeyser Wouter , Reiter Detlev , Baelmans Martine
Published: December 2014

Shape optimization methods, as commonly applied in aerodynamic design applications, have recently been adapted for use in nuclear fusion divertor target design. The resulting algorithms are very efficient compared to the standard use of numerical edge plasma simulations as analysis tools only. In this paper, we highlight some numerical aspects of the underlying algorithm, focusing on a correct, nine‐point discretization of the fluxes and the need for an adjoint pressure correction equation. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Mathematical Description and Algorithmization of Expert Knowledge for the Support of the Topology Optimization of Crashworthiness Structures
Authors: Ortmann Christopher , Schumacher Axel
Published: December 2014

This contribution deals with the mathematical description and algorithmization of expert knowledge so that this expert knowledge can be used within automatic optimization procedures with a focus on the topology optimization of crashworthiness structures. Up to now, a purely mathematical topology optimization of crashworthiness structures is not possible. The reasons for that are the nonlinearities coming from the large displacements and rotations, contact phenomena and complex material behaviour (e.g. plasticity, failure and strain rate dependency). One approach to overcome these problems by using heuristics based on expert knowledge and an application example are shown in this contribution. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Convergence of Parareal with spatial coarsening
Authors: Ruprecht Daniel
Published: December 2014

The effect is investigated of using a reduced spatial resolution in the coarse propagator of the time‐parallel Parareal method for a finite difference discretization of the linear advection‐diffusion equation. It is found that convergence can critically depend on the order of the interpolation used to transfer the coarse propagator solution to the fine mesh in the correction step. The effect also strongly depends on the employed spatial and temporal resolution. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Prediction of damage in cold bulk forming processes
Authors: Zapara Maksim , Augenstein Eva , Helm Dirk
Published: December 2014

In the present paper a practically relevant extension of the known modelling methods with regard to the description of forming limits of steels typically used in the cold bulk forming is developed and implemented in a commercial finite element code Abaqus. The modeling approach is based on the so‐called micromechanical damage concepts which represent the microstructure evolution more detailed than phenomenological models and, therefore, provide better prediction of damage and failure during the forming process. Particularly, the well‐known damage models of Gurson as well as Gologanu‐Leblond are considered. It is shown that in combination with fracture criteria such models are able to describe failure in bulk forming. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Differential inclusions and Young measures involving prescribed Jacobians
Authors: Rindler Filip
Published: December 2014

In elasticity theory, one naturally requires that the Jacobian determinant of the deformation is positive or even a‐priori prescribed (e.g. for incompressibility). However, such strongly non‐linear and non‐convex constraints are difficult to deal with in mathematical models. This short note, which is based on joint work with K. Koumatos and E. Wiedemann, presents various recent results on how this constraint can be manipulated in subcritical Sobolev spaces, where the integrability exponent is less than the dimension. In particular, we give a characterization theorem for Young measures under this side constraint. This is in the spirit of the celebrated Kinderlehrer–Pedregal Theorem and based on convex integration and “geometry” in matrix space. Finally, applications to approximation in Sobolev spaces and to the failure of lower semicontinuity for certain integral functionals with “realistic” growth conditions are given. (© 2014 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)
High‐efficiency impact modifier prepared by coagulation emulsion polymerization through internal voiding toughening mechanism
Authors: Jiang H. Y. , Liu B. J. , Deng Y. J. , Ma J. Y. , Cao C. L. , Zhang H. X.
Published: December 2014

This paper was an application of our previous study on particle coagulation mechanism (Colloid Polym Sci 291: 2385‐2398, 2013), and the effect of coagulation particle of acrylic impact modifiers (ACR) on polymer blend properties was investigated. The compatibility was relevant with the properties of shell phase rather than the structure of core phase. The rubber content was found to be the main influencing factor for toughening when rubber content less than 5%. However, when it reached to 7%, the dispersion of rubber became the primary parameter to dominate the toughness. The highest impact strength of poly(vinyl chloride) (PVC) toughened by coagulation particles was 1656 J/m, nearly 56 times than pure PVC, whereas only 45 times was reached when toughening by traditional ACR prepared by seeded emulsion polymerization; moreover, the brittle–ductile transition happened in advanced of 2 phr at ACR content. Scanning electron microscopy results showed that the shear yielding of the matrix and rubber cavitation were the major toughening mechanisms. Furthermore, the high performance of blend responsible for coagulation particles was discussed. Copyright © 2014 John Wiley & Sons, Ltd.
Protein tyrosine nitration: A signaling mechanism conserved from yeast to man
Authors: Bottari Serge P.
Published: December 2014

Although protein nitration had already been reported in the late forties and found to specifically affect tyrosine residues 20 years later, it was not until the early nineties that this post‐translational modification was reported to occur in vivo in mammalian cells. Over the years, this protein modification has increasingly proven to play a major role in a variety of physiological mechanisms through redox signaling and pathological conditions through nitro‐oxidative stress, from protozoan parasites to humans. In this issue (Proteomics 2015, 15, 580–590), Kang et al. report the identification of the nitroproteome during mating in the yeast Saccharomyces cerevisiae and most interestingly on the changes in nitration induced by the mating signal α‐factor of several of these proteins. The correlation of these modifications with the biological functions of these proteins strongly suggests a role for protein nitration in mating signal transduction in yeast, thereby confirming the conservation of this pathway throughout the evolution from unicellular eukaryotes to man. The ubiquity of protein tyrosine nitration, whose importance is now also recognized in plants, further highlights its significance as an essential signaling mechanism in eukaryotes.
Thermal Stability of Plasma Generated Oxygenated Functionalities on Carbon Nanotubes
Authors: Hordy Nathan , Meunier Jean‐Luc , Coulombe Sylvain
Published: December 2014

Colloidal suspensions of functionalized carbon nanotubes (CNT nanofluids) have the potential to be used in a variety of applications, many of which require operation at elevated temperatures. In this study, we examine what effect exposure to an argon/oxygen/ethane RF glow discharge plasma has on the surface chemistry and structure of CNTs and what happens to the plasma‐generated functionalities at high temperatures. An analysis performed using X‐ray photoelectron spectroscopy and Raman spectroscopy indicates that longer and higher power plasma treatments decrease the sp2 graphitic nature of the CNTs without increasing the degree of oxygen functional groups. Heating of the functionalized‐CNTs up to 350 °C in air and 600 °C in argon, both lead to a substantial decrease in the surface oxygen concentration, which can be attributed to the decomposition of carboxylic functionalities at low temperatures (< 350 °C).
The contrast‐to‐noise ratio for image quality evaluation in scanning electron microscopy
Authors: Timischl F.
Published: December 2014

The contrast‐to‐noise ratio (CNR) is presented and characterized as a tool for quantitative noise measurement of scanning electron microscope (SEM) images. Analogies as well as differences between the CNR and the widely used signal‐to‐noise ratio (SNR) are analytically and experimentally investigated. With respect to practical SEM image evaluation using the contrast‐to‐noise ratio, a standard specimen and an evaluation program are presented. SCANNING 37:54–62, 2015. © 2014 Wiley Periodicals, Inc.
Visualizing web server attacks: patterns in PHPIDS logs‡
Authors: Alsaleh Mansour , Alarifi Abdulrahman , Alqahtani Abdullah , Al‐Salman AbdulMalik
Published: December 2014

The prevalence and severity of application‐layer vulnerabilities increase dramatically their corresponding attacks. In this paper, we present an extension to PHPIDS, an open source intrusion detection and prevention system for PHP‐based web applications, to visualize its security log. Our usage of security data visualization is motivated by the fact that most security defense systems are mainly based on text‐based logs for recording security‐related events, which are difficult to analyze and correlate. The proposed extension analyzes PHPIDS logs, correlates these logs with the corresponding web server logs, and plots the security‐related events. We use a set of tightly coupled visual representations of hypertext transfer protocol server requests containing known and suspicious malicious content, to provide system administrators and security analysts with fine‐grained visual‐based querying capabilities. We present multiple case studies to demonstrate the ability of our PHPIDS visualization extension to support security analysts with analytic reasoning and decision making in response to ongoing web server attacks. Experimenting the proposed PHPIDS visualization extension on real‐world datasets shows promise for providing complementary information for effective situational awareness. Copyright © 2014 John Wiley & Sons, Ltd.
Influence of Coke Reactivity on Softening‐Melting Dropping Behavior of Iron‐Bearing Burden
Authors: Tuo Biyang , Wang Jianli , Yao Yanli , Yang Junjie
Published: December 2014

The influences of the different reactivity cokes on softening‐melting dropping of iron‐bearing burden were studied by melting‐dropping experiment. The pressure difference and shrinkage rate of burden layer, as well as the burden reduction degree at the same temperature were also analyzed. The results show that the softening and melting starting temperature reduces from 1200 to 1160 °C, and the softening and melting end temperature increases from 1290 to 1320 °C, while the melting ending temperature is unchanged and the dropping temperature of molten iron reduces from 1413 to 1380 °C, when the coke reactivity increases from 24.76 to 65.16%. Softening‐melting temperature interval increases with the improvement of coke reactivity based on the above temperatures change, meanwhile, melting temperature interval and the dropping temperature interval (ΔT3 = Td − TP) reduces, respectively. In addition, the shrinkage rate of charge column decreases and the permeability of charge column get better when the coke reactivity increases from 24.76 to 65.16%. The softening‐melting and dropping characteristic evaluation of iron‐bearing burden reduces with the improvement of coke reactivity. Appropriately increasing coke reactivity may improve charge column permeability and increase softening‐melting and dropping characteristic of iron‐bearing burden, therefore, it is of great significance for saving energy and reducing consumption of blast furnace smelting.
Narrative Diversity and Sympathetic Abortion: What Online Storytelling Reveals About the Prescribed Norms of the Mainstream Movements
Authors: Allen Mallary
Published: December 2014

Social movement scholarship demonstrates the importance of formula stories in raising awareness for social causes. The stories put forth by the opposing sides of the abortion rights issue in the United States utilize sympathetic narratives in furthering their arguments for and against abortion rights respectively, but differences in each side's narrative strategies are instructive in understanding current reproductive debate discourse. This article is a qualitative examination of abortion narratives published on two websites, one pro‐life and one pro‐choice. Chief among my findings are that narratives for each cause support opposed views of women's appropriate contemporary social roles and that authors' reported approaches to pregnancy and abortion are instrumental in constructing these broader understandings. Narratives posted by pro‐choice authors are confined by circumstantial norms surrounding unintended pregnancy (such as young age, student status, and first‐time pregnancy) as well as by a requirement to attribute empowering outcomes to the abortion decision. Pro‐life authors discuss a broader array of circumstances surrounding their pregnancies with narratives ultimately unified by themes of intense regret followed by atonement.
Risk assessment based on condition and importance criteria for power transformer in Thailand transmission network
Authors: Suwanasri Thanapong Y , Suwanasri Cattareeya , Phadungthin Rattanakorn
Published: December 2014

This paper proposes an innovative risk‐assessment strategy based on condition and importance criteria for power transformer maintenance in a transmission network. The condition assessment is performed by the analysis of different diagnosis methods such as electrical test, insulating oil test, and visual inspection. The importance assessment is evaluated from various aspects such as load criticality, impact on system stability, possibility of failure, failure consequence, damage to property, as well as social impact and environmental concerns. Weighting and scoring techniques are applied to determine the actual condition and importance of the power transformer with regard to condition and importance aspects. By combining the condition and importance assessment, the overall risk to the power transformer is assessed and differentiated into nine categories in the risk matrix from the lowest to the highest risk. Additionally, by applying distance ‘d’ technique, the risk‐based assessment matrix for the power transformer can be identified into five zones: healthy, good, moderate, bad, and risky. These five zones are also represented by color indicators as green, blue, yellow, orange, and red, which are further interpreted to five steps of maintenance tasks. The transformer with longer distance ‘d’ is subjected to higher risk and should be maintained first. By this method, a total of 19 power transformers were analyzed and are presented as examples for risk‐based maintenance. Then, risks of a total 598 power transformers are shown in the risk matrix. A computerized web application program is developed for practical implementation in a utility in Thailand. Finally, the systematic risk assessment and maintenance task of the power transformer fleet in Thailand are effectively managed. Thereby, the total maintenance cost of power transformer can be reduced. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
Semi‐blind source separation using binary masking and independent vector analysis
Authors: Tachioka Yuuki , Narita Tomohiro , Ishii Jun
Published: December 2014

Recent prevalence of speech recognition system increases the opportunity of simultaneous recognition of multiple speakers' utterances. There are two types of source separation methods: physical and statistical. The former is based on the physical information such as a direction of arrival of sound sources. The latter only uses statistical independence. The advantage of the former is fast computation and effectiveness with precise information; and that of the latter is no need for physical information, which leads to the robustness of measurement errors. In this paper, we propose to combine these approaches effectively. Experiments on a speech recognition task show that the proposed method can achieve the upper limit performance of the two approaches. © 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.
The perception of emotion in body expressions
Authors: de Gelder B. , de Borst A.W. , Watson R.
Published: December 2014

During communication, we perceive and express emotional information through many different channels, including facial expressions, prosody, body motion, and posture. Although historically the human body has been perceived primarily as a tool for actions, there is now increased understanding that the body is also an important medium for emotional expression. Indeed, research on emotional body language is rapidly emerging as a new field in cognitive and affective neuroscience. This article reviews how whole‐body signals are processed and understood, at the behavioral and neural levels, with specific reference to their role in emotional communication. The first part of this review outlines brain regions and spectrotemporal dynamics underlying perception of isolated neutral and affective bodies, the second part details the contextual effects on body emotion recognition, and final part discusses body processing on a subconscious level. More specifically, research has shown that body expressions as compared with neutral bodies draw upon a larger network of regions responsible for action observation and preparation, emotion processing, body processing, and integrative processes. Results from neurotypical populations and masking paradigms suggest that subconscious processing of affective bodies relies on a specific subset of these regions. Moreover, recent evidence has shown that emotional information from the face, voice, and body all interact, with body motion and posture often highlighting and intensifying the emotion expressed in the face and voice. WIREs Cogn Sci 2015, 6:149–158. doi: 10.1002/wcs.1335

This article is categorized under:

Neuroscience > Cognition
Morality Framing in U.S. Drug Control Policy: An Example From Marijuana Decriminalization
Authors: Ferraiolo Kathleen
Published: December 2014

The politics of so‐called “morality policies” including same‐sex marriage, abortion, gambling, and drug control have captured the attention of the public and social scientists in recent years. Drawing on data from journalistic accounts, legislative transcripts, elite interviews, and document analysis, this study examines the extensiveness of morality talk in debates over marijuana decriminalization in the United States. The results indicate that critics deployed moral (decriminalization sends the wrong message to youth, decreases risk perception, and promotes “normalization”), mixed (decriminalization has negative effects for families, communities, and society), and non‐moral (decriminalization negatively impacts individuals vis‐à‐vis physical, mental, and social health) arguments. The results both improve our understanding of the factors that will shape United States marijuana policy in the future and offer theoretical implications for our understanding of morality policy as a substantive category of public policy.
Exploring Leadership Team Behaviors and Subordinate Employee Attitudes in VA Hospitals
Authors: Yanovsky Boris I. , Osatuke Katerine , Shoda Elizabeth A. , Ramsel Dee
Published: December 2014

A top management team (TMT) is an integral component of an organization as it serves the role of a primary leader. The dynamics between TMTs and their subordinate organizational units are similar to those between individual leaders and their subordinates in that both (TMTs and individual leaders) exert a level of influence over their subordinate entities. This study sought to investigate a TMT's influence as a leader within the organization, by applying the two‐factor leadership theory to the relationship between TMTs and subordinate units. All but three examined workplace climate measures were significantly related to TMT behaviors. Organizational culture exhibited the strongest relationships, with all significant correlations ranging between 0.17 and 0.27. Our findings suggest that the composition of hospital TMTs can have implications for units providing direct care to patients. These findings may be of particular interest to administrators who are involved in building effective TMTs.
Toward biosensors for the detection of circulating microRNA as a cancer biomarker: an overview of the challenges and successes
Authors: Tavallaie Roya , De Almeida Swahnnya R. M. , Gooding J. Justin
Published: December 2014

Considerable attention has been dedicated to developing feasible point‐of‐care tests for cancer diagnosis and prognosis. An ideal biomarker for clinical use should be easily assayed with minimally invasive medical procedures but possess high sensitivity and specificity. The role of microRNAs (miRNAs) in the regulation of different cellular processes, the unique altered patterns in cancer patients and presence in body fluids in the stable form, points to their clinical utility as blood‐based biomarkers for diagnosis, prognosis, and treatment of cancer. Although a variety of selective and sensitive laboratory‐based methods are already exist for the detection of circulating miRNA, having a simple, low‐cost and rapid assay, which could be routinely used in clinical practice, is still required. Among different approaches that have developed for circulating miRNA detection, biosensors, due to the high sensitivity, ease of use, short assay time, non‐toxic experimental steps, and adaptability to point‐of‐care testing, exhibit very attractive properties for developing portable devices. With this view, we present an overview of some of the challenges that still need to be met to be able to use circulating miRNAs in clinical practice, including their clinical significance, sample preparation, and detection. In particular, we highlight the recent advances in the rapidly developing area of biosensors for circulating miRNA detection, along with future prospects and challenges. WIREs Nanomed Nanobiotechnol 2015, 7:580–592. doi: 10.1002/wnan.1324

This article is categorized under:

Diagnostic Tools > Biosensing

Diagnostic Tools > Diagnostic Nanodevices
Concerns in measurement of healthy eating and physical activity standards implementation
Authors: Hohman Katherine H. , Mantinan Karah D.
Published: December 2014

As part of its 2011 commitment to the Partnership for Healthier America, the YMCA of the USA (Y‐USA) pledged that by 2015, 85 percent of its local Y associations with early childhood or afterschool programs would have at least one program site that met 100 percent of the Y‐USA's healthy eating and physical activity (HEPA) standards. To inform the measurement and monitoring of HEPA standards, the Y‐USA designed a thirty‐three‐item online survey to assess which HEPA standards were being met in afterschool program sites each year in order to track progress over time. Verification activities including direct observation, key informant interviews, and document review generated overall compliance ratings for each standard. Compliance ratings were then compared to the self‐reported survey results to determine the validity of the survey for assessing each HEPA standard. The survey had variable accuracy when compared to the validation methods. This chapter aims to inform the measurement and monitoring of HEPA standards implementation in larger afterschool networks by reporting on learnings from the Y‐USA's early efforts in its network.
Creating healthier afterschool environments in the Healthy Eating Active Communities program
Authors: Hinkle Arnell J. , Yoshida Sallie
Published: December 2014

Afterschool programs in California have the potential to play a major role in obesity prevention given that they serve close to a million low‐income children. A five‐year initiative called the Healthy Eating Active Communities (HEAC) was funded in 2005 by the California Endowment to demonstrate that disparities related to childhood obesity and diabetes could be reduced in communities that offered families accessible and affordable opportunities for healthy eating and physical activity. The afterschool program setting constituted one of five key settings targeted in the initiative. This chapter describes the HEAC afterschool program initiative, reviews findings from the HEAC afterschool program nutrition and physical activity evaluation, and shares strategies that were used to implement the five‐year training and technical assistance intervention.
Effects of a competency‐based professional development training on children's physical activity and staff physical activity promotion in summer day camps
Authors: Weaver R. Glenn , Beets Michael W. , Turner‐McGrievy Gabrielle , Webster Collin A. , Moore Justin
Published: December 2014

The YMCA of the USA serves more than nine million youth in its summer day camping programs nationwide. In spring 2011, the YMCA of Columbia, SC, with support from the University of South Carolina, adopted a competency‐based staff‐level training approach in an attempt to align staff behaviors with the YMCA of the USA new physical activity standards for summer camp programs. This chapter presents findings from a multiyear evaluation of a competency‐based training approach using a single group design with preassessments and multiple postassessments. Training consisted of participatory exercises and video demonstrations. Data on staff physical activity promotion behaviors were collected using SOSPAN, an instrument that utilizes momentary time sampling to record instances of staff physical activity promotion behaviors consistent with physical activity standards. This chapter describes how a competency‐based professional development training may be effective at increasing physical activity promoting and decreasing physical activity discouraging staff behaviors and related child activity levels.