bluuebunny/crossref_metadata_2025 huggingface dataset:
Physical-limits-constrained minimum velocity norm coordinating scheme for wheeled mobile redundant manipulators
Authors: Zhang Yunong , Li Weibing , Zhang Zhijun
Published: April 2014

In order to resolve the redundancy of a wheeled mobile redundant manipulator comprising a two-wheel-drive mobile platform and a 6-degree-of-freedom manipulator, a physical-limits-constrained (PLC) minimum velocity norm (MVN) coordinating scheme (termed as PLC-MVN-C scheme) is proposed and investigated. Such a scheme can not only coordinate the mobile platform and the manipulator to fulfill the end-effector task and to achieve the desired optimal index (i.e., minimizing the norm of the rotational velocities of the wheels and the joint velocities of the manipulator) but also consider the physical limits of the robot (i.e., the joint-angle limits and joint-velocity limits of the manipulator as well as the rotational velocity limits of the wheels). The scheme is then reformulated as a quadratic program (QP) subject to equality and bound constraints, and is solved by a discrete QP solver, i.e., a numerical algorithm based on piecewise-linear projection equations (PLPE). Simulation results substantiate the efficacy and accuracy of such a PLC-MVN-C scheme and the corresponding discrete PLPE-based QP solver.
ECONOMETRIC ANALYSIS OF CONTINUOUS TIME MODELS: A SURVEY OF PETER PHILLIPS’S WORK AND SOME NEW RESULTS
Authors: Yu Jun
Published: April 2014

Econometric analysis of continuous time models has drawn the attention of Peter Phillips for 40 years, resulting in many important publications by him. In these publications he has dealt with a wide range of continuous time models and the associated econometric problems. He has investigated problems from univariate equations to systems of equations, from asymptotic theory to finite sample issues, from parametric models to nonparametric models, from identification problems to estimation and inference problems, and from stationary models to nonstationary and nearly nonstationary models. This paper provides an overview of Peter Phillips’ contributions in the continuous time econometrics literature. We review the problems that have been tackled by him, outline the main techniques suggested by him, and discuss the main results obtained by him. Based on his early work, we compare the performance of three asymptotic distributions in a simple setup. Results indicate that thein-fillasymptotics significantly outperforms thelong-spanasymptotics and thedoubleasymptotics.
A scalable approach for ideation in biologically inspired design
Authors: Vandevenne Dennis , Verhaegen Paul-Armand , Dewulf Simon , Duflou Joost R.
Published: April 2014

This paper presents a bioinspiration approach that is able to scalably leverage the ever-growing body of biological information in natural-language format. The ideation tool AskNature, developed by the Biomimicry 3.8 Institute, is expanded with an algorithm for automated classification of biological strategies into the Biomimicry Taxonomy, a three-level, hierarchical information structure that organizes AskNature's database. In this way, the manual work entailed by the classification of biological strategies can be alleviated. Thus, the bottleneck is removed that currently prevents the integration of large numbers of biological strategies. To demonstrate the feasibility of building a scalable bioideation system, this paper presents tests that classify biological strategies from AskNature's reference database for those Biomimicry Taxonomy classes that currently hold sufficient reference documents.
POLITICS THROUGH POTTERY: A VIEW OF THE PRECLASSIC-CLASSIC TRANSITION FROM BUILDING B, GROUP II, HOLMUL, GUATEMALA
Authors: Callaghan Michael G.
Published: April 2014

Building B of Group II at Holmul, Guatemala, is well known in Maya archaeology for its unique series of superimposed tombs, some of which contain rare large deposits of ceramic material dating to the Terminal Preclassic period (a.d.1–250). However, the building also contains large deposits of early facet Early Classic (a.d.250–400) material, as well as the remains of a potential title holding elite. This article presents the current ceramic sequence for the Holmul region and a re-evaluation of the ceramic material from all rooms in Building B Group II in light of new discoveries at sites within the Holmul region and the greater Maya lowlands. The result is a new hypothesis about what social processes are manifested through Terminal Preclassic period orange slipped pottery, which suggests that the vessels associated with deposits in Buidling B may represent changes in elite diacritical feasting events during this period. These feasts, and the preparations made for them, may have simultaneously integrated social groups within a polity while also reinforcing differences between them during two turbulent epochs of Maya political history—namely, the late facet of the Terminal Preclassic period (a.d.150–250) and the early facet of the Early Classic period (a.d.250–400).
STRUCTURE 5N2 (“GROUP A”): A RÍO BEC PARADIGMATIC PALACE?
Authors: Michelet Dominique , Nondédéo Philippe , Patrois Julie , Gillot Céline , Gómez Emyly González
Published: April 2014

Structure 5N2 (initially named “Group A”) at Río Bec is the first ruin in the region to have been recorded and is its most important towered building. While it is reasonable to question the specific role such emblematic monumental structures played in the region's sociopolitical organization, precise data concerning their dating, construction history, and functions has been lacking. The recent study of Structure 5N2 has improved our understanding of this building type and of the structure itself, which combines a private residential sector (that astonishingly includes a central pyramid-temple) and a public space. The structure's construction history also reveals a great deal. Originally it consisted of only a tandem two-room residence constructed at roughlya.d.700–720. Arounda.d.830–850 the original residence was transformed into a large palace, which remained unfinished until abandonment just aftera.d.950. Analysis of the final building, replaced in the process of transformation to the settlement around Structure 5N2, also enables us to explore the social and economic dimensions of its dramatic but incomplete growth.
On the concept of probability
Authors: MUGUR-SCHÄCHTER MIOARA
Published: April 2014

In this paper, we discuss the crucial but little-known fact that, as Kolmogorov himself claimed, the mathematical theory of probabilities cannot be applied to factual probabilistic situations. This is because it is nowhere specified how, for any given particular random phenomenon, we should construct, effectively and without circularity, the specific and stable distribution law that gives the individual numerical probabilities for the set of possible outcomes. Furthermore, we do not even know what significance we should attach to the simple assertion that such a distribution law “exists”. We call this problem Kolmogorov's aporia†.

We provide a solution to this aporia in this paper. To do this, we first propose a general interpretation of the concept of probability on the basis of an example, and then develop it into a non-circular and effective general algorithm of semantic integration for the factual probability law involved in a specific factual probabilistic situation. The development of the algorithm starts from the fact that the concept of probability, unlike a statistic, does not apply to naturally pre-existing situations but is a conceptual artefact that ensures, locally in space and time, a predictability that is more stable and definite than that permitted by primary statistical data.

The algorithm, which is constructed within a method of relativised conceptualisation, leads to a probability distribution expressed in rational numbers and involving a sort of quantification of the factual concept of probability. Furthermore, it also provides a definite meaning to the simple assertion that a factual probability law exists. We also show that the semantic integration algorithm is compatible with the weak law of large numbers.

The results we give provide a complete solution to Kolmogorov's aporia. They also define a concept of probability that is explicitly organised into a semantic, epistemological and syntactic whole. In a broader context, our results can be regarded as a strong, pragmatic and operational specification of Karl Popper's propensity interpretation of probabilities.
Cognitive Functioning and Late-Life Depression
Authors: Koenig Aaron M. , Bhalla Rishi K. , Butters Meryl A.
Published: March 2014

This brief report provides an introduction to the topic of cognitive functioning in late-life depression (LLD). In addition to providing a review of the literature, we present a framework for understanding the heterogeneity of cognitive outcomes in this highly prevalent disorder. In addition, we discuss the relationship between LLD and dementia, and highlight the importance of regularly assessing cognitive functioning in older adults who present with depressive symptoms. If cognitive deficits are discovered during a neuropsychological assessment, we recommend referral to a geriatric psychiatrist or cognitive neurologist, for evaluation and treatment of the patient’s symptoms. (JINS, 2014,20, 1–7)
High-Energy Resolution Electron Energy-Loss Spectroscopy Study of Interband Transitions Characteristic to Single-Walled Carbon Nanotubes
Authors: Sato Yohei , Terauchi Masami
Published: March 2014

An electron energy-loss spectroscopic (EELS) study using a monochromator transmission electron microscope was conducted for investigating the dielectric response of isolated single-walled carbon nanotubes (SWCNTs) owing to interband transitions characteristic to chiral structures. Individual chiral structures of the SWCNTs were determined by electron diffraction patterns. EELS spectra obtained from isolated SWCNTs showed sharp peaks below π plasmon energy of 5 eV, which were attributed to the characteristic interband transitions of SWCNTs. In addition, unexpected shoulder structures were observed at the higher energy side of each sharp peak. Simulations of EELS spectra by using the continuum dielectric theory showed that an origin of the shoulder structures was because of the surface dipole mode along the circumference direction of the SWCNT. It was noticed that the electron excitation energies obtained by EELS were slightly higher than those of optical studies, which might be because of the inelastic scattering process with the momentum transfers. To interpret the discrepancy between the EELS and optical experiments, it is necessary to conduct more accurate simulation including the first principle calculation for the band structure of SWCNTs.
b-GENERALIZED DERIVATIONS OF SEMIPRIME RINGS HAVING NILPOTENT VALUES
Authors: TAMER KOŞAN M. , LEE TSIU-KWEN
Published: March 2014

Let $\def \xmlpi #1{}\def \mathsfbi #1{\boldsymbol {\mathsf {#1}}}\let \le =\leqslant \let \leq =\leqslant \let \ge =\geqslant \let \geq =\geqslant \def \Pr {\mathit {Pr}}\def \Fr {\mathit {Fr}}\def \Rey {\mathit {Re}}R$ be a semiprime ring with extended centroid $C$ and with maximal right ring of quotients $Q_{mr}(R)$. Let $d{:}\ R\to Q_{mr}(R)$ be an additive map and $b\in Q_{mr}(R)$. An additive map $\delta {:}\ R\to Q_{mr}(R)$ is called a (left) $b$-generalized derivation with associated map $d$ if $\delta (xy)=\delta (x)y+bxd(y)$ for all $x, y\in R$. This gives a unified viewpoint of derivations, generalized derivations and generalized $\sigma $-derivations with an X-inner automorphism $\sigma $. We give a complete characterization of $b$-generalized derivations of $R$ having nilpotent values of bounded index. This extends several known results in the literature.
Supporting Personalisation: The Challenges in Translating the Expectations of National Policy into Developments in Local Services and Their Underpinning Information Systems
Authors: Hill Penelope
Published: April 2014

Social care policy is actively promoting integrated and personalised care. Local organisations are starting to re-engineer their business processes, review front line practice, develop new operational tools and revise their information systems to support and deliver these new approaches. This article draws on a study undertaken in one local organisation as it began to implement its response to these expectations. It uses structuration theory to explore how the macro agendas described by policy and legislation are translated into local perspectives and then further refracted through the lens of operational practice, shaping the business tools which deliver the change. The evidence suggests that there needs to be a better understanding of how the expectations of policy are interpreted – and potentially distorted – through their translation into local practice, and of the role that information and information services play in enabling, or disabling the delivery of those expectations at the front line.
MODALITY AND AXIOMATIC THEORIES OF TRUTH I: FRIEDMAN-SHEARD
Authors: STERN JOHANNES
Published: April 2014

In this investigation we explore a general strategy for constructing modal theories where the modal notion is conceived as a predicate. The idea of this strategy is to develop modal theories over axiomatic theories of truth. In this first paper of our two part investigation we develop the general strategy and then apply it to the axiomatic theory of truth Friedman-Sheard. We thereby obtain the theory Modal Friedman-Sheard. The theory Modal Friedman-Sheard is then discussed from three different perspectives. First, we show that Modal Friedman-Sheard preserves theoremhood modulo translation with respect to modal operator logic. Second, we turn to semantic aspects and develop a modal semantics for the newly developed theory. Third, we investigate whether the modal predicate of Modal Friedman-Sheard can be understood along the lines of a proposal of Kripke, namely as a truth predicate modified by a modal operator.
Labor repertoires, neoliberal regimes and US hegemony: what ‘deviant’ Italy tells us of OECD unions’ paths to power
Authors: Gentile Antonina
Published: March 2014

This paper notes the tendency of ‘social movement unionism’ scholarship on both sides of the Atlantic to focus on and prescribe the citizen repertoire as the single most important repertoire of labor for challenging neoliberal globalization. Consistent with liberal conceptions of civil society and theories of participatory democracy, it implicitly dismisses political unionism as a path to labor’s revitalization. It also assumes epochal change and confines neoliberalism to the post-Washington Consensus era. Deviant case analysis of Italian labor’s use oftworepertoires (the citizen and the labor repertoire) and of its two regimes of capitalism (in succession, a post-WWII neoliberal regime and a post-1970 corporatist regime) over the course of the ‘American Century’ gives pause to both these contentions. This study relates labor’s citizen repertoire to the era of US hegemony that promotes changes in party-government that tend to reproduce the image of the archetypically neoliberal American polity: a polity that is devoid of ‘labor’ as a recognized category of the political community, is low in social rights, and, relatedly, is devoid of a party of labor. In this neoliberal political order, labor is perennially locked into the category of ‘citizen’ and reliant on the citizen repertoire. By contrast, the survival of parties of labor in non-US polities during the post-war wave of neoliberalism permitted union movements a routeawayfrom labor-decategorizing orders – political unionism. Now, in the post-Washington Consensus wave of neoliberal regime change, that route is more onerous owing to Third Way changes in parties of labor. The major challenge for labor movements that have experienced regime change to a neoliberal polity is in directing their efforts and even their new citizen repertoire to the task of recapturing parties of labor or to creating new ones – or risk long-term US-style labor decategorization.
Sectorial substrate-integrated half-mode near-field sensors for biological liquid characterization
Authors: Meyne Nora , Jacob Arne F.
Published: April 2014

Two compact resonant near-field sensors are introduced for the characterization of aqueous solutions at 5 GHz. They are based on folded substrate-integrate circular half-mode resonators with a planar sensing tip. Owing to the planar design, the sensor is simple and cheap to manufacture, and a sample can be easily coupled to the resonator from the top. The operating principle of the sensor is explained and verified by both simulation and measurement. The radiation of the sensors is quantified by means of a quality factor analysis. Finally, a previously introduced calibration method based on the perturbation theory is applied to the sensors and its accuracy is improved by choosing more suitable reference materials.
RF-MEMS multi-mode-matching networks for GaN power transistors
Authors: Figur Sascha A. , van Raay Friedbert , Quay Rüdiger , Vietzorreck Larissa , Ziegler Volker
Published: April 2014

This work presents radio-frequency-microelectromechanical-system (RF-MEMS)-based tunable input- and output-matching networks for a multi-band gallium nitride (GaN) power-amplifier applications. In the first part, circuit designs are shown and characterized for a fixed operation mode of the transistor, i.e. either a maximum-output-power- or a maximum-power-added-efficiency (PAE)-mode, which are finally combined into a multi-mode-matching network (M3N); the M3N allows to tune the operation mode of the transistor independently of its operational frequency. The matching networks are designed to provide optimum matching for the power amplifier at three to six different operating frequencies for maximum-output-power- and maximum-PAE-mode. In the frequency range from 3.5 to 8.5 GHz, return losses of 10 dB and higher were measured and insertion losses of 0.5–1.9 dB were demonstrated for the output-matching networks. Further characterizations were performed to test the dependency on the RF-input power, and no changes were observed up to power levels of 34 dBm when cold-switched.
Circulating CD1c+ DCs are superior at activating Th2 responses upon Phl p stimulation compared with basophils and pDCs
Authors: Rydnert Frida , Lundberg Kristina , Greiff Lennart , Lindstedt Malin
Published: April 2014

The contributing role of circulating human dendritic cell (DC) populations and basophils in the presentation and augmentation of Th2 responses remains to be determined. The present study aimed at elucidating the functional role of CD1c+ myeloid DCs (mDCs), CD123+ plasmacytoid DCs (pDCs), monocyte‐derived DCs and basophils in allergen presentation and Th2 activation. By coculturing Phleum pratense (Phl p)‐pulsed CD1c+ mDCs, CD123+ pDCs, monocyte‐derived DCs and basophils with autologous CD4+ effector memory T cells, we assessed T‐cell proliferation as well as the frequency of interleukin‐4‐ and interferon‐γ‐producing T cells. Interestingly, a Th2‐stimulating ability was observed for Phl p‐challenged CD1c+ mDCs and monocyte‐derived DCs, while CD123+ pDCs and basophils did not affect the Th‐balance. In addition, both Phl p‐pulsed CD1c+ mDCs and monocyte‐derived DCs stimulated increased T‐cell proliferation compared to basophils and CD123+ pDCs. Together, these results point to a prominent role for circulating CD1c+ mDCs in allergen presentation and augmentation of Th2 responses, making them promising therapeutic targets for Type I hypersensitivity reactions.
Memory Impedance in TiO2 based Metal-Insulator-Metal Devices
Authors: Qingjiang Li , Khiat Ali , Salaoru Iulia , Papavassiliou Christos , Hui Xu , Prodromakis Themistoklis
Published: March 2014

Large attention has recently been given to a novel technology named memristor, for having the potential of becoming the new electronic device standard. Yet, its manifestation as the fourth missing element is rather controversial among scientists. Here we demonstrate that TiO2-based metal-insulator-metal devices are more than just a memory-resistor. They possess resistive, capacitive and inductive components that can concurrently be programmed; essentially exhibiting a convolution of memristive, memcapacitive and meminductive effects. We show how non-zero crossing current-voltage hysteresis loops can appear and we experimentally demonstrate their frequency response as memcapacitive and meminductive effects become dominant.
High-density biosynthetic fuels: the intersection of heterogeneous catalysis and metabolic engineering
Authors: Harvey Benjamin G. , Meylemans Heather A. , Gough Raina V. , Quintana Roxanne L. , Garrison Michael D. , Bruno Thomas J.
Published: March 2014

Renewable multicyclic sesquiterpenes were converted into high density fuels with net heats of combustion up to 13% higher than Jet-A.
Experimental determination of electrostatic properties of Na–X zeolite from high resolution X-ray diffraction
Authors: Porcher F. F. , Souhassou M. , Lecomte C. E. P.
Published: March 2014

High resolution single crystal X-ray diffraction is used to obtain the electron density and atomic charges in Na–X zeolite. The Coulomb potential and interaction energies are calculated for a given Na+distribution and are discussed in connection with cation site affinities and adsorption of water molecules in the zeolite.
Synthesis, structure, spectroscopy of four novel supramolecular complexes and cytotoxicity study by application of multiple parallel perfused microbioreactors
Authors: Guan Qing-Lin , Liu Zhi , Wei Wen-Juan , Xing Yong-Heng , Liu Jing , Zhang Rui , Hou Ya-Nan , Wang Xuan , Bai Feng-Ying
Published: April 2014

Synthesis of four supramolecular complexes and study of their cytotoxicity using multiple parallel perfused microbioreactors.
Highly efficient and bendable organic solar cells using a three-dimensional transparent conducting electrode
Authors: Wang Wei , Bae Tae-Sung , Park Yeon Hyun , Kim Dong Ho , Lee Sunghun , Min Guanghui , Lee Gun-Hwan , Song Myungkwan , Yun Jungheum
Published: April 2014

A highly efficient 3D transparent conducting electrode of bendable organic solar cells is achieved by fabricating a multilayer consisting of an ITO nanoparticle array superimposed on an ITO–AgOx–ITO electrode on a flexible polymer substrate.
Whole cell-SELEX aptamers for fluorescence staining of frozen hepatocellular carcinoma tissues
Authors: Yang Xiaohai , Zhang Xiuzhi , Wang Kemin , Wang Qing , Tan Yuyu , Guo Qiuping , Chen Mian , Zhou Yu
Published: April 2014

A newly developed hepatocellular carcinoma-specific aptamer for highly specific identifying SMMC-7721 carcinoma in real biological samples.
Stability, durability and regeneration ability of a novel Ag-based photocatalyst, Ag2Nb4O11
Authors: Dong Hongjun , Chen Gang , Sun Jingxue , Feng Yujie , Li Chunmei , Lv Chade
Published: April 2014

A novel Ag-based photocatalyst, Ag2Nb4O11, exhibits universal photodegradation activity for dyes as well as high stability, durability and regeneration ability.
Direct access to 1,2,3-triazoles through organocatalytic 1,3-dipolar cycloaddition reaction of allyl ketones with azides
Authors: Li Wenjun , Du Zhiyun , Huang Jiayao , Jia Qianfa , Zhang Kun , Wang Jian
Published: April 2014

A general organocatalytic 1,3-dipolar cycloaddition reaction between allyl ketones and various azides is reported. The reaction is catalyzed by a secondary amine to generate substituted 1,2,3-triazoles with high levels of regioselectivity.
Microfluidics for single-cell genetic analysis
Authors: Thompson A. M. , Paguirigan A. L. , Kreutz J. E. , Radich J. P. , Chiu D. T.
Published: March 2014

New tools are needed to study single-cell genetics, and a microfluidic approach offers unique advantages and challenges.
Elucidating structural features of an entirely carbohydrate cancer vaccine construct employing circular dichroism and fluorescent labeling
Authors: Trabbic Kevin R. , De Silva Ravindra A. , Andreana Peter R.
Published: April 2014

Structural changes of PS A1 does not alter function.
Rapid formation of AgnX(X = S, Cl, PO4, C2O4) nanotubes via an acid-etching anion exchange reaction
Authors: Li Jingjing , Yang Wenlong , Ning Jiqiang , Zhong Yijun , Hu Yong
Published: April 2014

A series of silver-compound AgnX nanotubes, including Ag2S, AgCl, Ag3PO4, and Ag2C2O4, were successfully prepared from pregrown Ag2CO3 nanorod templates. The anion exchange process takes place in non-aqueous solutions just at room temperature and completes within 10 minutes.
Nanohelices by shadow growth
Authors: Gibbs John G. , Mark Andrew G. , Lee Tung-Chun , Eslami Sahand , Schamel Debora , Fischer Peer
Published: April 2014

Complex, hybrid nanohelices fabricated by dynamic shadow growth in a high-throughput manner exhibit novel optical, magnetic and mechanical properties.
Efficient simulations of the aqueous bio-interface of graphitic nanostructures with a polarisable model
Authors: Hughes Zak E. , Tomásio Susana M. , Walsh Tiffany R.
Published: April 2014

Simulations of the aqueous interface between graphitic nanostructures and biomolecules are efficiently realised via the polarisable GRAPPA model.
Multifunctional ScF3:Ln3+(Ln = Tb, Eu, Yb, Er, Tm and Ho) nano/microcrystals: hydrothermal/solvothermal synthesis, electronic structure, magnetism and tunable luminescence properties
Authors: Han Lili , Wang Yuhua , Guo Linna , Zhao Lei , Tao Ye
Published: April 2014

ScF3nanocubes as a new matrix for tunable PL, CL, and UC luminescence and ferromagnetic properties are developed.
Enhancing circularly polarised luminescence by extending the π-conjugation of axially chiral compounds
Authors: Kitayama Yoko , Amako Tomoyuki , Suzuki Nozomu , Fujiki Michiya , Imai Yoshitane
Published: April 2014

π-Conjugated (R)- and (S)-2,2′-diphenyl-4-biphenanthrol (VAPOL) exhibited an efficient circularly polarised luminescence (CPL) (∼1.3 × 10−3) at 376 nm. By comparison, (R)- and (S)-3,3-diphenyl-2,2-bi-1-naphthol (VANOL) exhibited no CPL.
ATRP with a light switch: photoinduced ATRP using a household fluorescent lamp
Authors: Zhang Tao , Chen Tao , Amin Ihsan , Jordan Rainer
Published: April 2014

We report on photoinduced ATRP in solution and from surfaces using a standard fluorescent lamp as the light source.
Effects of ionic liquids on the reaction kinetics of a laccase–mediator system
Authors: Harwardt Nora , Stripling Natascha , Roth Simon , Liu Haifeng , Schwaneberg Ulrich , Spiess Antje C.
Published: April 2014

Conductivity and viscosity explain part of the effect of ionic liquids on the laccase–mediator system kinetics, but not all.
A water soluble calcium–sodium based coordination polymer: selective release of calcium at specific binding sites on proteins
Authors: Gaur Ruchi , Susmitha Ambadipudi , Chary K. V. R. , Mishra Lallan
Published: April 2014

A calcium–sodium based water soluble coordination complex, [{Ca4Na(EGTA)2(H2O)13}n·NO3] (EGTA = ethylene bis(oxyethylenenitrilo)tetraaceticacid), has been synthesized hydrothermally and characterized using spectroscopic and single crystal X-ray diffraction techniques.
Nanocomposite coatings with stimuli-responsive catalytic activity
Authors: Koenig Meike , Magerl David , Philipp Martine , Eichhorn Klaus-Jochen , Müller Martin , Müller-Buschbaum Peter , Stamm Manfred , Uhlmann Petra
Published: April 2014

Stimuli-responsive catalytic coatings are fabricated byin situ-synthesis of metallic nanoparticles in binary poly(N-isopropyl acrylamide)–poly(2-vinyl pyridine) brushes.
Optimal power allocation for asymmetric analogue network coding in cognitive radio
Authors: Hu Mi , Ge Jianhua , Shi Xiaoye
Published: April 2014

In this study, the optimal power allocation (OPA) problem is studied for the two‐way relay channel employing the analogue network coding protocol with the asymmetric traffic requirements in a cognitive radio network. The OPA scheme is proposed by maximising the sum‐rate of the success delivery bit from the secondary user (SU) perspective subject to the sum‐power constraint and the interference power threshold (IPT) constraints to the primary user (PU). In particular, for the purpose of accomplishing the power allocation more realistically, the interference to each other between the PU and the SU and the relay is taken into consideration and by solving the optimisation problem composed for each case, the closed form expressions of each node power are obtained. All the simulation results have demonstrated that the system with the proposed scheme outperforms the equal power allocation (EPA) scheme irrespective of the IPT. When the IPT constraint is introduced, the sum‐rate of the success delivery bit of the SU communication converges to a certain level with the increasing total power. Meanwhile, the proposed strategy is superior to the conventional EPA scheme for any relay location, which is more remarkable when the relay is located on either end node regardless of the traffic symmetry or the asymmetry.
Robust object tracking algorithm based on sparse eigenbasis
Authors: Li Jing , Wang Junzheng
Published: April 2014

To reduce the computation and to improve the performance of object detection and tracking algorithm with object appearance variation, a tracker based on sparse eigenbasis is proposed. According to the compressive sensing theory, the objects are described in a low‐dimensional sub‐space representation based on Karhunen–Loeve transform learned online. Meanwhile, combining the Bayesian inference, an adaptive object tracker is presented. First, the authors represent the appearance of the object in a low‐dimensional sub‐space, then the authors obtain the optimal estimation of the state parameters by Bayesian inference. Finally, the authors update the eigenbasis space using the optimal observations. Experimental results show that the proposed method is able to track the objects effectively and robustly under temporary occlusion and large illumination changes.
Robust visual tracking based on watershed regions
Authors: Yu Wangsheng , Tian Xiaohua , Hou Zhiqiang , Zha Yufei
Published: April 2014

Robust visual tracking is a very challenging problem especially when the target undergoes large appearance variation. In this study, the authors propose an efficient and effective tracker based on watershed regions. As middle‐level visual cues, watershed regions contain more semantics information than low‐level features, and reflect more structure information than high‐level model. First, the authors manually select the target template in initial frame, and predict the target candidate in the next frame using motion prediction. Then, the authors utilise marker‐based watershed algorithm to obtain the watershed regions of target template and candidate template, and describe each region with multiple features. Next, the authors calculate the nearest neighbour in feature space to match the watershed regions and construct an affine relation from target template to candidate template. Finally, the authors resolve the affine relation to calculate the final tracking result, and update the template for the following tracking. The authors test their tracker on some challenging sequences with appearance variation range from illumination change, partial occlusion, pose change to background clutters and compare it with some state‐of‐the‐art works. Experiment results indicate that the proposed tracker is robust to the large appearance variation and exceeds the state‐of‐the‐art trackers in most situations.
Mid‐term electricity market clearing price forecasting using multiple least squares support vector machines
Authors: Yan Xing , Chowdhury Nurul A.
Published: April 2014

Mid‐term electricity market clearing price (MCP) forecasting has become essential for resources reallocation, maintenance scheduling, bilateral contracting, budgeting and planning purposes. Currently, there are many techniques available for short‐term electricity MCP forecasting, but very little has been done in the area of mid‐term electricity MCP forecasting. A multiple least squares support vector machine (LSSVM) based mid‐term electricity MCP forecasting model is proposed in this study. Data classification and price forecasting modules are designed to first pre‐process the input data into corresponding price zones, and then forecast the electricity price. The proposed model showed improved forecasting accuracy on both peak prices and overall system compared to the forecasting model using a single LSSVM. PJM interconnection data are used to test the proposed model.
Wide area measurement/wide area information‐based control strategy to fast relieve overloads in a self‐healing power grid
Authors: Jiao Zaibin , Wang Xiaobing , Gong Heteng
Published: April 2014

Self‐healing is one of the characteristics of the smart grid. A self‐healing power grid can identify and react to disturbance and restore power systems with little or even no human intervention. A wide area measurement (WAM) and wide area information (WAI)‐based control strategy is proposed to fast react to overloads and restore the power grid in the self‐healing power grid. The basic principle is to redistribute the power flow of a contingency transmission line to other lines with unified power flow controller (UPFC). To implement the control strategy, the reverse current network and nodal analysis method, instead of the iteration algorithm and optimisation method, is applied to redistribute the power flow. The proposed WAM/WAI‐based nodal analysis can relieve overloads quickly and effectively while realising the control objective accurately. Moreover, a grid simplification method is applied to further reduce computation cost. IEEE 39‐bus test system‐based simulation is applied to verify the proposed control strategy. The results show that the control strategy can relieve overloads effectively in about tens of milliseconds. Thus, it could be an online controller for a self‐healing power grid to deal with harmful contingencies.
Vehicle trajectory extraction by simple two‐dimensional model matching at low camera angles in intersection
Authors: Lu Guangquan , Kong Longfei , Wang Yunpeng , Tian Daxin
Published: April 2014

Vehicle trajectories are commonly used to analyse driving behaviour and traffic safety. Traditional blob detection methods are limited in providing the accurate locations of vehicles when these are monitored from a low position. The authors propose a novel method of vehicle detection by utilising the projection line between the vehicle side and the ground plane. The line, which is extremely close to the surface of the road plane, provides location and orientation information. Therefore the authors’ method further locates vehicles by matching the two‐dimensional (2D) model with the vehicle bottom by using a projection line and a projective transformation matrix. The model‐based tracking method is used to track the detected vehicles, and a Kalman filter is combined to predict the locations of vehicles. The output is a set of microscopic parameters which include vehicle ID, trajectory, velocity, acceleration, orientation and angular speed, respectively. The experimental results are acceptable in terms of vehicle detection, vehicle tracking, trajectory extraction and computation time, respectively.
Compressive sensing‐based approach to the design of linear robust sparse antenna arrays with physical size constraint
Authors: Hawes Matthew B. , Liu Wei
Published: April 2014

In sparse arrays, the randomness of antenna locations avoids the introduction of grating lobes, while allowing adjacent antenna spacings to be greater than half a wavelength. This means a larger array size can be implemented using a relatively small number of antennas. However, careful consideration has to be given to antenna locations to ensure that an acceptable performance level is achieved. Model perturbations can also cause steering vector errors, which in turn cause discrepancies in the array's response, making robust arrays desirable. This study presents various compressive sensing‐based methods that can solve this problem, while also imposing the antenna size as a constraint on the minimum adjacent antenna separations. Narrowband and multiband design examples are presented to verify the effectiveness of the proposed design methods, with comparisons being drawn with a previously proposed genetic algorithm‐based approach.
Near field multifocusing on antenna arrays via non‐convex optimisation
Authors: Álvarez Jana , Ayestarán Rafael G. , León Germán , Herrán Luis F. , Arboleya Ana , López‐Fernández Jesús A. , Las‐Heras Fernando
Published: April 2014

An optimisation framework for near field multifocusing on antenna arrays is proposed. Its aim is to obtain the feeding weights that must be applied to the elements of the array so that the antenna focuses on two or more targets simultaneously. The method is based on the definition of a proper cost function, which is minimised using an optimisation algorithm over an equivalent least squares problem. The success of the technique is noted in the fact that different array parameters can be obtained: magnitude and phase of the array elements or only phase synthesis. In order to show the efficiency of the method, several tests are carried out using different arrays and optimisation parameters. The simulation, manufacture and measurement of an 8 × 8 planar array able to focus on two different targets is also performed. Results show how the framework can be applied to general arrays and demanding requirements, so it may be easily extended to different synthesis problems besides multifocusing.
Effect of non‐pinned carrier density above threshold in InAs quantum dot and quantum dash lasers
Authors: Marko Igor P. , Adams Alf R. , Massé Nicolas F. , Sweeney Stephen J.
Published: April 2014

The impact of carrier density non‐pinning above threshold on laser performance is studied in different quantum dot/dash lasers with room temperature emission wavelengths of 0.98–1.52 µm. Owing to inhomogeneity in the active region, the non‐pinning may be important even above room temperature because of the non‐thermal carrier distribution between the dots. This has a large impact on the external differential efficiency and the output power of the devices. In the presence of non‐radiative recombination, non‐pinning will further decrease the output power and the slope efficiency because of a significant reduction in the number of carriers available for stimulated emission.
Design optimisation of metallic sub‐wavelength nanowire lasers
Authors: Sattar Zubaida A. , Shore Keith Alan , Wang Zengbo
Published: April 2014

Design optimisation of metal‐clad cylindrical nanowire semiconductor lasers is undertaken. Attention is focused on structures having GaN as the material platform and utilising silver for the metal cladding. The lasing characteristics of such structures are explored using both the transfer matrix method and the finite element method for operating wavelengths from 330 to 830 nm and for metal cladding thicknesses in the range of 5–20 nm. Specifically, calculations are performed for the modal confinement factor, modal gain and device length across this wide parameter space. For representative structures, it is shown that lower‐order TE and TM mode lasing can be supported in devices having cavity lengths of the order of 2 and 18 µm, respectively.
Bistability of threshold in quantum dash‐in‐a‐well lasers
Authors: Harnedy Patrick E. , Osborne Simon , Joshi Siddharth , Lelarge François , O'Reilly Eoin P.
Published: April 2014

The authors observe a bistability of threshold in a quantum dash ridge‐waveguide laser diode at temperatures below 230 K. A giant and sometimes negative characteristic temperature, T0, is measured at temperatures between 230 K and 320 K. They analyse the temperature dependent light‐current characteristics of this device, and a similar device with lower barriers, to gain an insight into the mechanism causing bistable behaviour. A rate equation model shows localisation and passive saturable absorption as the causes of the bistable behaviour in the higher barrier laser at low temperature. They find good qualitative agreement between the experimental and the theoretical results.
Modelling and controller design of quasi‐Z‐source inverter with battery‐based photovoltaic power system
Authors: Liu Yushan , Ge Baoming , Abu‐Rub Haitham , Peng Fang Zheng
Published: April 2014

The quasi‐Z‐source inverter (qZSI) with battery can balance the stochastic fluctuations of PV power injected to the grid/load, but there is no literature to disclose its modelling and controller design in detail. This study proposed a dynamic small‐signal model of qZSI with battery and a control strategy for photovoltaic (PV) power generation system. The built model discloses the dynamic relationship of PV panel voltage, battery current, quasi‐Z‐source inductor currents and capacitor voltages. The proposed control method achieves the grid‐tie operation with unity power factor, PV panel's maximum power point tracking and battery management. The novel space vector modulation for the qZSI divides the total shoot‐through time interval into six equal parts per control cycle to be combined into the six switching moments, and lower inductor current ripple and higher inverter efficiency are performed. The experimental and simulation results verify the theoretical analysis and proposed control methods.
Analysis of microgrid inverter droop controller with virtual output impedance under non‐linear load condition
Authors: Wang Wen , Zeng Xiangjun , Tang Xin , Tang Ci
Published: April 2014

With the existence of virtual impedance, the load harmonic currents would decrease the detection accuracy of fundamental power calculated in DQ method, thus influence the performance of droop control system in microgrid inverters. Quantitative analysis of the fundamental power detection error is conducted and general expressions of inverter output power in the presence of virtual impedance are established. The concept of virtual harmonic power is proposed to approximately describe the error. Furthermore, the small signal stability analysis method is applied to present a detailed performance analysis of the control system as virtual harmonic power is taken into consideration. The analysis indicates that under the non‐linear load condition, the value of droop coefficients and the type of designed virtual output impedance will influence the stability of the control system, which means that droop coefficients and virtual output impedance should be carefully selected to gain sufficient stability margin. Simulation and experiment are both carried out and comparison of linear and non‐linear load condition is presented in detail which verifies the theoretical analysis.
Performance analysis of natural frequency‐based multiple radar target recognition for multiple‐input–multiple‐output radar application
Authors: Lee Joon‐Ho , Jeong So‐Hee , Park Gun‐Su , Lee Young‐Chul , Cho Sung‐Woo
Published: April 2014

In this study, the authors propose an analytic performance analysis applicable to the case that there are multiple radar responses from distinct radar targets at resonance frequency range. Multistatic radar can employ multiple receivers, which are usually located far away enough not to simultaneously receive the response from the same target. It is assumed that the authors receive returns from M distinct radar targets. In this study, they assume that each receiver receives only one target response, which is reasonable assumption for the multistatic receivers which are separated enough not to receive the same target response together. Using the projections of all the M target responses onto the column space associated with the specific kth radar target, they try to recognise which radar target response is from the kth radar. The derived expressions are validated by comparing the results obtained from the derived expressions with the results from the Monte Carlo simulation.
Comments on ‘Constrained total least‐squares localisation algorithm using time difference of arrival and frequency difference of arrival measurements with sensor location uncertainties’
Authors: Qu Fuyong , Meng Xiangwei
Published: April 2014

In a recent study, Yu et al., a constrained total least‐squares algorithm to estimate the position and velocity of a moving source with sensor location uncertainties was proposed. However, two errors appeared in this study. In the comments, the two errors are discussed and some corrections are presented.
Ionospheric effects on three‐dimensional imaging of L‐band geosynchronous circular synthetic aperture radar
Authors: Kou Leilei , Xiang Maosheng , Wang Xiaoqing
Published: April 2014

Circular synthetic aperture radar (SAR) imaging on the geosynchronous orbit has many potential advantages, such as high‐resolution three‐dimensional (3D) imaging and continuous surveillance of broad area. The mission considered is an L‐band geosynchronous circular SAR (GEOCSAR) with full aperture measurement. Since the integration time of GEOCSAR can be as long as 24 h, the orbit altitude is about 36 000 km and the coverage may reach 1/3 of the Earth's surface. The spatial and temporal variation of the ionosphere may impose significant effects on 3D imaging performance of GEOCSAR. The effects of ionospheric spatial variation including vertical and horizontal structure, the ionospheric turbulence and the ionospheric temporal variation are discussed. The analysis shows that the temporal variation of the ionospheric electron content during the synthetic aperture and the ionospheric turbulence may severely affect the GEOCSAR focusing performance on the XY plane. The vertical and horizontal structure of the ionosphere will cause image shift, and the dispersion effect is negligible.
Unsupervised classification based on non‐negative eigenvalue decomposition and Wishart classifier
Authors: Wang Chunle , Yu Weidong , Wang Robert , Deng Yunkai , Zhao Fengjun , Lu Youchun
Published: April 2014

In this study, the authors propose an unsupervised terrain and land‐use classification algorithm for polarimetric synthetic aperture radar (SAR) image analysis. Under the non‐reflection symmetry condition, the non‐negative eigenvalue decomposition (NNED) employing Arii volume scattering model is derived. They first apply NNED to divide pixels into three categories of surface, volume and double bounce scatterings. Then the pixels in each category are further divided into several classes based on the scattering characteristic parameter of the dominant scattering component. Utilising the initial classification result as training sets, the complex Wishart classifier can then be performed within each category or beyond categories to refine the final classification result. The effectiveness of this algorithm is demonstrated using the German Aerospace Center's E‐SAR polarimetric data acquired over the Oberpfaffenhofen area in Germany.
Discovery of significant pathways in breast cancer metastasis via module extraction and comparison
Authors: Wang Xiaochen , Qian Huajie , Zhang Shuqin
Published: April 2014

Discovering significant pathways rather than single genes or small gene sets involved in metastasis is becoming more and more important in the study of breast cancer. Many researches have shed light on this problem. However, most of the existing works are relying on some priori biological information, which may bring bias to the models. The authors propose a new method that detects metastasis‐related pathways by identifying and comparing modules in metastasis and non‐metastasis gene co‐expression networks. The gene co‐expression networks are built by Pearson correlation coefficients, and then the modules inferred in these two networks are compared. In metastasis and non‐metastasis networks, 36 and 41 significant modules are identified. Also, 27.8% (metastasis) and 29.3% (non‐metastasis) of the modules are enriched significantly for one or several pathways with p ‐value <0.05. Many breast cancer genes including RB1, CCND1 and TP53 are included in these identified pathways. Five significant pathways are discovered only in metastasis network: glycolysis pathway, cell adhesion molecules, focal adhesion, stathmin and breast cancer resistance to antimicrotubule agents, and cytosolic DNA‐sensing pathway. The first three pathways have been proved to be closely associated with metastasis. The rest two can be taken as a guide for future research in breast cancer metastasis.