bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimal control of human‐like musculoskeletal arm: Prediction of trajectory and muscle forces
Authors: Sharifi Mojtaba , Pourtakdoust Seid H. , Parnianpour Mohamad 
Published: March 2016

SummaryOptimal trajectory and muscle forces of a human‐like musculoskeletal arm are predicted for planar point‐to‐point movements using optimal control theory. The central nervous system (CNS) is modeled as an optimal controller that performs a reaching motion to final states via minimization of an objective function. For the CNS strategy, a cubic function of muscles stresses is considered as an appropriate objective function that minimizes muscles fatigue. A two‐DOF nonlinear musculoskeletal planar arm model with four states and six muscle actuators is used for the evaluation of the proposed optimal strategy. The nonlinear variational formulation of the corresponding optimal control problem is developed and solved using the method of variation of extremals. The initial and (desired) final states (position and velocity) are used as input kinematic information, while the problem constraints include the motion range of each joint, maximum allowable muscle tension, and stability requirements. The resulting optimal trajectories are compared with experimental data as well as those corresponding to recent researches on model predictions of human arm movements. It is demonstrated that the proposed optimal control strategy using minimum fatigue criterion is more realistic in prediction of motion trajectories in comparison with previous work that has utilized minimum joints' torque criterion. Accordingly, minimization of muscles fatigue is an effective biomechanical criterion for the CNS in prediction of point‐to‐point human arm motions. Copyright © 2016 John Wiley & Sons, Ltd.
Innovative Filter Solutions for Hyperspectral Imaging
Authors: Pust Oliver 
Published: March 2016

AbstractHyperspectral imaging (HSI) has been used for a couple of decades in applications such as satellite imaging, air reconnaissance and other not overly price sensitive markets. Still, there is no clear definition of hyperspectral imaging. Sometimes techniques that produce 2D images with more than the typical three RGB colors or spectral channels — for example by inclusion of a near‐infrared channel — are already called hyperspectral. Mostly though, this is not considered sufficient. Typically, even ten spectral channels are still to be called multi‐spectral rather than hyperspectral.
The tangled bank of amino acids
Authors: Goldstein Richard A. , Pollock David D. 
Published: March 2016

AbstractThe use of amino acid substitution matrices to model protein evolution has yielded important insights into both the evolutionary process and the properties of specific protein families. In order to make these models tractable, standard substitution matrices represent the average results of the evolutionary process rather than the underlying molecular biophysics and population genetics, treating proteins as a set of independently evolving sites rather than as an integrated biomolecular entity. With advances in computing and the increasing availability of sequence data, we now have an opportunity to move beyond current substitution matrices to more interpretable mechanistic models with greater fidelity to the evolutionary process of mutation and selection and the holistic nature of the selective constraints. As part of this endeavour, we consider how epistatic interactions induce spatial and temporal rate heterogeneity, and demonstrate how these generally ignored factors can reconcile standard substitution rate matrices and the underlying biology, allowing us to better understand the meaning of these substitution rates. Using computational simulations of protein evolution, we can demonstrate the importance of both spatial and temporal heterogeneity in modelling protein evolution.
Optimizing the parameter space for increased crystallinity of silicon nanoparticles grown in the gas phase
Authors: Mohan Akshatha , Schropp Ruud E. I. , Poulios Ioannis , Goedheer Wim J. , Rath Jatin K. 
Published: March 2016

Various plasma process parameters such as coupled power, process pressure (p), gas flow, and source gas ratios (SiH4:H2) play crucial roles in determining the size and crystallinity of the synthesized Si nanoparticles (NPs). One of the less studied parameters for NP growth is the inter‐electrode distance, d. Our study focuses on the effect of d and demonstrates how a reactor with larger d (refers to d = 30 mm) is a simple method to enhance the crystalline ratio of NPs produced in them compared with a standard d (refers to d = 10 mm). Increasing d or p is not strictly equivalent, and we show that for our reactor p > 0.8 mbar is most effective at d = 30 mm to obtain purely crystalline NPs. We also establish how the larger d opens up a wider parameter space for the synthesis of crystalline Si NPs.Completely crystalline silicon NPs synthesized in this study at p = 0.8 mbar and larger d of 30 mm.
Effect of superlattice on light output power of InGaN‐based light‐emitting diodes fabricated on underlying GaN substrates with different dislocation densities
Authors: Sugimoto Kohei , Denpo Yusho , Okada Narihito , Tadatomo Kazuyuki 
Published: March 2016

AbstractWe evaluated the electrical properties of InGaN‐based light‐emitting diodes (LEDs) with a surperlattice (SL) layer just below the MQWs for forming V‐shaped pits (V‐pits) on underlying GaN substrates with different dislocation densities (DDs). The SL was effective for improving the EL intensity for all the LEDs with different DDs. However, the improvement ratio decreased with decreasing DD. The SL is effective for performance improvement of the LEDs with high DDs. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Exciton recombination in spontaneously formed and artificial quantum wells AlxGa1‐xN/AlyGa1‐yN (x<y∼0.8)
Authors: Toropov A. A. , Shevchenko E. A. , Shubina T. V. , Jmerik V. N. , Nechaev D. V. , Pozina G. , Bergman P. , Monemar B. , Rouvimov S. , Ivanov S. V. 
Published: March 2016

AbstractWe report on photoluminescence (PL) spectroscopy and electron microscopy studies of an AlGaN quantum well (QW) structure grown by molecular beam epitaxy under metal‐rich conditions with substrate rotation. Both techniques reveal unintentional formation within the AlGaN barriers of a quasiperiodic structure of thin Ga‐rich layers, whose period is controlled by both the substrate rotation rate and the AlGaN growth rate. These compositional modulations act as 1‐3 monolayer thick QWs emitting below 250 nm with an internal quantum efficiency (IQE) as high as ∼30% at room temperature under weak excitation. Variational calculations of the QW exciton properties indicate that the observed high IQE can result from strong three‐dimensional localization of the excitons confined in the narrow QWs. (© 2015 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Self‐assembly of tomato bushy stunt viruses on silicon under the influence of the drop shape, drop volume and the virus concentration
Authors: Rink V. , Braun M. , Boonrod K. , Müller‐Renno C. , Krczal G. , Ziegler Ch. 
Published: March 2016

AbstractSelf‐assembled plant viruses, here tomato bushy stunt virus (TBSV), are interesting building blocks in nanobiotechnology. Especially genetically modified virus types show enhanced self‐assembling properties compared to the wild type (wt) virus. In this article important aspects of the self‐assembly of tetra histidine (4xHis) TBSV (histidine side chains on the capsid surface) are presented in detail. Different virus concentrations show a different wetting behavior of the solid substrate. This leads to different coverages depending on the position within the sample. In the center of the virus covered area, the most stable conditions are found and often also the highest coverage. If these central areas are compared to samples prepared with different virus concentrations, a large variation of the coverage can be detected. For the desired homogeneous monolayer of the virus, the concentration has thus to be optimized. In addition, it could be shown that the drop volume does not influence the homogeneity of the surface coverage. (© 2016 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Electride: from computational characterization to theoretical design
Authors: Zhao Songtao , Kan Erjun , Li Zhenyu 
Published: March 2016

Electrides are a class of materials in which anionic electrons are spatially separated from the positively charged crystalline framework. With such a unique structure, electrides show great potential in various applications, such as superconductivity, electronics, and catalysis. A number of organic and inorganic electrides have been successfully synthesized in experiment, and their novel electronic structures are studied both computationally and experimentally. Computational characterization can provide information which is difficult to be obtained from experiment. In electronic structure calculations, charge density, noncovalent interaction (NCI) index, electron localization function (ELF), and electrostatic potential (ESP) can be analyzed to identify anionic electrons in confined space. On the other hand, theoretical studies can also be used to design new electrides, such as in a recent instance of two‐dimensional (2D) electride screening. Alternatively, new applications and novel electron systems based on electrides can be explored theoretically. As an example, based on Ca2N electride, an intrinsic 2D electron gas system in free space (2DEG‐FS) has been proposed. With the aid of computational characterization and theoretical design, electride study will continue to be an important field in materials science. WIREs Comput Mol Sci 2016, 6:430–440. doi: 10.1002/wcms.1258This article is categorized under:

Structure and Mechanism > Computational Materials Science
Extended Virtues and the Boundaries of Persons
Authors: HOWELL ROBERT J. 
Published: March 2016

ABSTRACT:What sorts of things undergird a person's character and what does the answer tell us about the person's relationship to her body, her environment, and the people who surround her? For the purpose of ascribing virtue, vice, and character, what are the boundaries of the person? Traditionally, philosophers have accepted mentalism, the view that only mental features are relevant to character. Even philosophers inclined to say that character is partially constituted by nonmental features would be inclined to accept skindividualism: a person's virtue must involve a disposition that is wholly grounded by features inside the person's skin. Drawing from arguments in the philosophy of mind and data from social psychology, I argue that skindividualism is wrong. Virtues can be extended, in the sense that the grounds for a person's virtues might not be inside that individual's skin. If this is the case, persons are not skindividuals.
Correlation formulas for Markovian network processes in a random environment
Authors: Daduna Hans , Szekli Ryszard 
Published: March 2016

Abstract
We consider Markov processes, which describe, e.g. queueing network processes, in a random environment which influences the network by determining random breakdown of nodes, and the necessity of repair thereafter. Starting from an explicit steady-state distribution of product form available in the literature, we note that this steady-state distribution does not provide information about the correlation structure in time and space (over nodes). We study this correlation structure via one-step correlations for the queueing-environment process. Although formulas for absolute values of these correlations are complicated, the differences of correlations of related networks are simple and have a nice structure. We therefore compare two networks in a random environment having the same invariant distribution, and focus on the time behaviour of the processes when in such a network the environment changes or the rules for travelling are perturbed. Evaluating the comparison formulas we compare spectral gaps and asymptotic variances of related processes.
Duality and complete convergence for multi-type additive growth models
Authors: Foxall Eric 
Published: March 2016

Abstract
We consider a class of multi-type particle systems whose structure is similar to that of a contact process and show that additivity is equivalent to the existence of a dual process, extending a result of Harris. We prove a necessary and sufficient condition for the model to preserve positive correlations. We then show that complete convergence on Zd holds for a large subclass of models including the two-stage contact process and a household model, and give examples.
Theory of segmented particle filters
Authors: Chan Hock Peng , Heng Chiang-Wee , Jasra Ajay 
Published: March 2016

AbstractWe study the asymptotic behavior of a new particle filter approach for the estimation of hidden Markov models. In particular, we develop an algorithm where the latent-state sequence is segmented into multiple shorter portions, with an estimation technique based upon a separate particle filter in each portion. The partitioning facilitates the use of parallel processing, which reduces the wall-clock computational time. Based upon this approach, we introduce new estimators of the latent states and likelihood which have similar or better variance properties compared to estimators derived from standard particle filters. We show that the likelihood function estimator is unbiased, and show asymptotic normality of the underlying estimators.
On comparing coherent systems with heterogeneous components
Authors: Samaniego Francisco J. , Navarro Jorge 
Published: March 2016

Abstract
In this paper we investigate different methods that may be used to compare coherent systems having heterogeneous components. We consider both the case of systems with independent components and the case of systems with dependent components. In the first case, the comparisons are based on the new concept of the survival signature due to Coolen and Coolen-Maturi (2012) which extends the well-known concept of system signatures to the case of components with lifetimes that need not be independent and identically distributed. In the second case, the comparisons are based on the concept of distortion functions. A graphical procedure (called an RR-plot) is proposed as an alternative to the analytical methods when there are two types of components.
Generalised higher-order Kolmogorov scales
Authors: Boschung Jonas , Hennig Fabian , Gauding Michael , Pitsch Heinz , Peters Norbert 
Published: March 2016

Kolmogorov introduced dissipative scales based on the mean dissipation $\langle {\it\varepsilon}\rangle$ and the viscosity ${\it\nu}$, namely the Kolmogorov length ${\it\eta}=({\it\nu}^{3}/\langle {\it\varepsilon}\rangle )^{1/4}$ and the velocity $u_{{\it\eta}}=({\it\nu}\langle {\it\varepsilon}\rangle )^{1/4}$. However, the existence of smaller scales has been discussed in the literature based on phenomenological intermittency models. Here, we introduce exact dissipative scales for the even-order longitudinal structure functions. The derivation is based on exact relations between even-order moments of the longitudinal velocity gradient $(\partial u_{1}/\partial x_{1})^{2m}$ and the dissipation $\langle {\it\varepsilon}^{m}\rangle$. We then find a new length scale ${\it\eta}_{C,m}=({\it\nu}^{3}/\langle {\it\varepsilon}^{m/2}\rangle ^{2/m})^{1/4}$ and $u_{C,m}=({\it\nu}\langle {\it\varepsilon}^{m/2}\rangle ^{2/m})^{1/4}$, i.e. the dissipative scales depend rather on the moments of the dissipation $\langle {\it\varepsilon}^{m/2}\rangle$ and thus the full probability density function (p.d.f.) $P({\it\varepsilon})$ instead of powers of the mean $\langle {\it\varepsilon}\rangle ^{m/2}$. The results presented here are exact for longitudinal even-ordered structure functions under the assumptions of (local) isotropy, (local) homogeneity and incompressibility, and we find them to hold empirically also for the mixed and transverse as well as odd orders. We use direct numerical simulations (DNS) with Reynolds numbers from $Re_{{\it\lambda}}=88$ up to $Re_{{\it\lambda}}=754$ to compare the different scalings. We find that indeed $P({\it\varepsilon})$ or, more precisely, the scaling of $\langle {\it\varepsilon}^{m/2}\rangle /\langle {\it\varepsilon}\rangle ^{m/2}$ as a function of the Reynolds number is a key parameter, as it determines the ratio ${\it\eta}_{C,m}/{\it\eta}$ as well as the scaling of the moments of the velocity gradient p.d.f. As ${\it\eta}_{C,m}$ is smaller than ${\it\eta}$, this leads to a modification of the estimate of grid points required for DNS.
Comparison of 14C Collected by Precipitation and Gas-Strip Methods for Dating Groundwater
Authors: Nakata Kotaro , Hasegawa Takuma , Iwatsuki Teruki , Kato Toshihiro 
Published: March 2016

AbstractDissolved inorganic carbon (DIC) in groundwater is used to estimate the residence time based on radiocarbon concentration. DIC is usually extracted by a gas-strip or precipitation (SrCO3 or BaCO3) method. In this study, the gas-strip and precipitation methods of DIC were applied to both artificially prepared NaHCO3 solutions and natural groundwater to estimate the certainty of the two methods for 14C dating. 14C values obtained by the gas-strip method for NaHCO3 solutions with distinct salinity, DIC, and 14C concentrations were close to the theoretically predicted 14C value based on the 14C value of NaHCO3 powder. Conversely, the 14C value obtained by the precipitation method always showed higher values than the predicted values. The difference in 14C value between the gas-strip and precipitation methods was assumed to be caused by the contamination of modern carbon in the NaOH solution used in the precipitation method. The contamination of modern carbon derived from the NaOH solution during precipitation was found to range from less than 1 mg/L to about 1 mg/L. The applicability of the precipitation method for groundwater should be considered carefully according to the DIC, 14C concentration of groundwater, and purpose of the study being conducted.
Capturing Accuracy in Second Language Performance: The Case for a Weighted Clause Ratio
Authors: Foster Pauline , Wigglesworth Gillian 
Published: March 2016

ABSTRACTAs increasing numbers of research papers in applied linguistics, language learning, and assessment use discourse analysis techniques to assess accuracy in performance, it is timely to examine at a detailed level the wide variety of measures employed. Ideally, measures need to capture accuracy in as valid and reliable a way as possible, but this has proved elusive. In this article, we systematically review the variety of different measures in used in these fields, both global and local, before presenting a more finely tuned weighted clause ratio measure which classifies errors at different levels, that is, those that seriously impede communication, those that impair communication to some degree, and those that do not impair communication at all. The problem of reliably identifying these levels is discussed, followed by an analysis of samples from written and spoken second language performance data. This new measure, grounded in a comprehensive review of prior practice in the field, has the advantages of being relatively easy to use, measuring accuracy rather than error, and evaluating smaller increases in improved performance than have previously been possible.
Mode in Theoretical and Empirical TBLT Research: Advancing Research Agendas
Authors: Gilabert Roger , Manchón Rosa , Vasylets Olena 
Published: March 2016

ABSTRACTIn this article we explore how oral and written modes may differentially influence processes involved in second language acquisition (SLA) in the context of task-based language teaching (TBLT). We first start by reflecting on the differences between spoken and written language. In what follows, we provide a general description of tasks in relation to the SLA processes. We then establish the links between the learning processes and task phases/features in the two modes. Concluding that the role of mode has been underresearched, we call for a more integrative and mode-sensitive TBLT research agenda, in which hybridness of discourse (i.e., mingling of the two modes within one communicative event/task) is taken into account.
Non-Blazar Gamma-Ray Variables in the Galactic Plane: A New Class of Gamma-Ray Sources
Authors: Tavani Marco 
Published: March 2016

AbstractWe discuss recent detections of time-variable gamma-ray sources near the Galactic plane. A new bright gamma-ray transient was detected by EGRET in June 1995 near the Galactic center (GRO J1838-04). Also one of the most interesting unidentified gamma-ray sources in the plane, 2CG 135+1, was recently shown to be variable. Both GRO J1838-04 and 2CG 135+1 share many characteristics: variability of the gamma-ray flux within days/weeks, occasional peak gamma-ray emission of comparable flux (˜ 4 x 10-6ph cm-2s-1), absence of radio-loud spectrally-flat AGNs or prominent radio pulsars within their error boxes, lack of strong X-ray and/or hard X-ray counterparts. These characteristics do not match those of either gamma-ray blazars or isolated pulsars. Therefore, GRO J1838-04 and 2CG 135+1 provide strong evidence for the existence of a new class of variable gamma-ray sources.
Soft X-Ray Transients are Like ER UMA Cataclysmic Variables
Authors: Regső Enikő , Masetti Nicola 
Published: March 2016

AbstractWe discuss how soft X-ray transients exhibit light curves associated with two accretion-disc instabilities that are well known to operate in cataclysmic variables. A thermal instability that is due to hydrogen ionization leads to the transient nature but is modified by X-ray irradiation of the disc. Growth of the disc between the ensuing outbursts leads to a 3:1 commensurability instability at the outer edge of the disc that drives superoutbursts and produces superhumps in the lightcurve if the mass ratio is sufficiently small. Superhumps are observed only in the short period SU UMa CVs but black hole primaries allow SXTs to exhibit superoutbursts and superhumps at much larger periods. We point out similarities between SXT superhump shapes and those of the small class of ER UMa CVs, The similarity between these systems stems from the fact that the mass-transfer rates are almost large enough to stabilize the disc against the thermal instability in both cases.
Latitude Manifestations of the Solar Wind
Authors: Von Steiger R. 
Published: March 2016

AbstractDependencies of solar wind parameters as a function of latitude are presented and discussed, based on measurements of the Ulysses mission during times of declining or minimum solar activity. The heliosphere is found to be structured into a band of slow solar wind at low latitudes and two large high-speed streams from the polar coronal holes. Only small trends of solar wind parameters with heliolatitude are found within these streams. A small but significant temperature difference is seen between the south and the north polar coronal hole.
Large-Scale Structure and Termination of the Heliosphere
Authors: Macek W. M. 
Published: March 2016

AbstractThe question of the boundaries of the heliosphere is considered. The termination heliospheric shock should exist because the solar wind plasma flowing supersonically away from the Sun must make a transition to a subsonic flow. The heliopause is at the outermost extend of the solar wind. Beyond the heliopause lies the (very local) interstellar wind. Intensity of radio emissions at 2 to 3 kHz detected by the Voyager plasma wave instrument in the outer heliosphere can be explained provided that the electron beams generating Langmuir waves exist in the post-shock plasma due to secondary shocks in the compressed solar wind beyond the termination shock. The field strengths of Langmuir waves required to generate the second harmonic emissions are 50 – 100 μ V m-1. Alternatively, the emissions are generated in the vicinity of the heliopause. The Voyager 1 and 2 are proceeding toward a likely source region for Langmuir wave and these waves may be observed in situ in the near future.