Cover Picture: Proteomics 7-8'13

Cover Image: Background image © Mopic - Fotolia.com. Cover design by SCHULZ Grafik-Design.

     

Cover Picture: Proteomics 9-10'13

Cover Image: Foreground image taken from Tongzhong Ju et al., (pp. 618–631): IgA1 has normalO-glycans with a core 1 O-glycan decorated with sialic acids (purple diamonds) in either mono- or disiaylated structures. But in IgA1 from IgA nephropathy (IgAN) patients it is proposed that Tn and STn antigens lacking the core 1 O-glycan accumulate and contribute to IgAN. IgAN is the most common glomerulonephritis and results in renal failure in 20–40% of patients over 25 years of age. Deposition of IgA1 in the glomerular mesangium is thought to drive the disease. Background image, kindly provided by Tongzhong Ju, Richard D. Cummings, et al.: Human primary colorectal adenocarcinoma cells highly express Tn antigen. A formalin fixed paraffin-embedded tissue section of human primary colorectal adenocarcinoma was immunohistochemically stained with anti-Tn monoclonal antibody (Red) and counter staining with Haemotoxylin (Blue). The tumor cells are highly stained with anti-TnmAb. Cover design by SCHULZGrafik-Design.

     

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The cover image is based on the Research Article Consensus control of output‐constrained multi‐agent systems with unknown control directions under a directed graph by Gang Wang et al., https://doi.org/10.1002/rnc.4852 .

     

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The cover image is based on the Research Article Observer‐Based Cooperative Distributed Fault‐tolerant Model Predictive Control with Imperfect Network Communication and Asynchronous Measurements by Guannan Xiao and Fei Liu, https://doi.org/10.1002/rnc.4994 .

     

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The cover image is based on the Research Article Safe reinforcement learning for dynamical games by Yongliang Yang et al., https://doi.org/10.1002/rnc.4962 .

     

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The cover image is based on the Research Article High‐gain nonlinear observer‐based impedance control for deformable object cooperative teleoperation with nonlinear contact model by Zhenyu Lu et al., https://doi.org/10.1002/rnc.4880 .

     

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The cover image is based on the Research Article Robust control under worst‐case uncertainty for unknown nonlinear systems using modified reinforcement learning by Adolfo Perrusquía and Wen Yu, https://doi.org/10.1002/rnc.4911 .

     

A safe variant of the unsafe integer arithmetic of Java™

Computers are finite machines and, therefore, the arithmetic operations in a programming language are different from their mathematical counterparts. These restrictions seem not to have been, in general, fully appreciated in programming languages and in computer science textbooks. One example is the programming language Java, which makes it difficult to warn the user in cases in which arithmetic operations produce incorrect results. In this paper we look at integer arithmetic in Java and develop a safe variant of the arithmetic operations in Java. The design of the safe variant of , , , , and for the types byte , short , int and long reveals a number of deficiencies of Java in integer arithmetic, floating point arithmetic and program structure. Some of these deficiencies are also present in other contemporary programming languages. The paper therefore ends with some proposals for the design of the arithmetic elements of programming languages. Copyright © 2002 John Wiley & Sons, Ltd.     

ComVis-Sail: Comparative Sailing Performance Visualization for Coaching

During training sessions, sailors rely on feedback provided by the coaches to reinforce their skills and improve their performance. Nowadays, the incorporation of sensors on the boats enables coaches to potentially provide more informed feedback to the sailors. A common exercise during practice sessions, consists of two boats of the same class, sailing side by side in a straight line with different boat handling techniques. Coaches try to understand which techniques are that make one boat go faster than the other. The analysis of the obtained data from the boats is challenging given its multi-dimensional, time-varying and spatial nature. At present, coaches only rely on aggregated statistics reducing the complexity of the data, hereby losing local and temporal information. We describe a new domain characterization and present a visualization design that allows coaches to analyse the data, structuring their analysis and explore the data from different perspectives. A central element of the tool is the glyph design to intuitively represent and aggregate multiple aspects of the sensor data. We have conducted multiple user studies with naive users, sailors and coaches to evaluate the design and potential of the overall tool.

     

Decentralized weighted control for a class of large‐scale systems with multi‐modes

In this paper, the control synthesis problem for a class of large‐scale systems with multi‐modes that are called large‐scale switched systems is addressed. By introducing the concept of decentralized switching signal and the relevant decentralized average dwell time, the asymptotic stability and weighted ?₂ gain performance are investigated. It should be noted that the decentralized switching covers general switching cases for large‐scale switched systems, namely, it admits both time‐dependent switching signal and arbitrary switching signal blended in the decentralized switching. Then, on the basis of the analysis results, the decentralized weighted control scheme including state feedback controller gains and switching signals is studied. Several design algorithms are proposed to meet different controller design problems. Finally, numerical examples are provided to illustrate theoretical findings within this paper. Copyright © 2013 John Wiley & Sons, Ltd.     

Revisiting bounded context block‐sorting transformations

The Burrows–Wheeler Transform (BWT ) produces a permutation of a string X, denoted X^?, by sorting the n cyclic rotations of X into full lexicographical order and taking the last column of the resulting n×n matrix to be X^?. The transformation is reversible in time. In this paper, we consider an alteration to the process, called k‐BWT , where rotations are only sorted to a depth k. We propose new approaches to the forward and reverse transform, and show that the methods are efficient in practice. More than a decade ago, two algorithms were independently discovered for reversing k‐BWT , both of which run in time. Two recent algorithms have lowered the bounds for the reverse transformation to and, respectively. We examine the practical performance for these reversal algorithms. We find that the original approach is most efficient in practice, and investigates new approaches, aimed at further speeding reversal, which store precomputed context boundaries in the compressed file. By explicitly encoding the context boundaries, we present an reversal technique that is both efficient and effective. Finally, our study elucidates an inherently cache‐friendly – and hitherto unobserved – behavior in the reverse k‐BWT , which could lead to new applications of the k‐BWT transform. In contrast to previous empirical studies, we show that the partial transform can be reversed significantly faster than the full transform, without significantly affecting compression effectiveness. Copyright © 2011 John Wiley & Sons, Ltd.     

Controllability of Semilinear Systems of Parabolic Equations with Delay on the State

In this paper we prove the approximate controllability of the following semilinear system parabolic equations with delay on the state variable where Ω is a bounded domain in is a n × n non diagonal matrix whose eigenvalues are semi‐simple with non negative real part, the control u belongs to and B is a n × m matrix. Here τ≥0 is the maximum delay, which is supposed to be finite. We assume that the operator L:L²([?τ,0];Z)→Z is linear and bounded with and the nonlinear function f:[0,r] × IRⁿ×IR^m→IRⁿ is smooth and bounded.     

PIC — A language for typesetting graphics

PIC is a language for specifying pictures so that they can be typeset as an integral part of a document preparation system. The basic objects in PIC are boxes, lines, arrows, circles, ellipses, arcs and splines, which may be placed at positions specified absolutely or in terms of previous objects, and labeled with arbitrary text. The example below illustrates the general capabilities of the language. Most of the effort in designing PIC has gone into making it possible to specify the sizes and positions of objects with minimal use of absolute coordinates. This paper describes PIC, with primary emphasis on those aspects of the language that make it easy to use. The paper was typeset using PIC.     

Spatial camera orientation control by rotation‐minimizing directed frames

The use of rotation‐minimizing directed frames (RMDFs) for defining smoothly varying camera orientations along given spatial paths, in real or virtual environments, is proposed. A directed frame on a space curve is a varying orthonormal basis for ℝ³ such that coincides with the unit polar vector from the origin to each curve point, and such a frame is rotation‐minimizing if its angular velocity vector maintains a vanishing component along o . To facilitate computation of rotation‐minimizing directed frames, it is shown that the basic theory is equivalent to the established theory for rotation‐minimizing adapted frames—for which one frame vector coincides with the tangent at each curve point—if one replaces the given space curve by its anti‐hodograph (i.e., indefinite integral). A family of polynomial curves on which RMDFs can be computed exactly by a rational function integration, the Pythagorean (P) curves, is also introduced, together with algorithms for their construction. Copyright © 2009 John Wiley & Sons, Ltd.     

state estimation with fading measurements,randomly varying nonlinearities and probabilistic distributed delays

In this paper, the state estimation problem is investigated for a class of discrete‐time stochastic systems in simultaneous presence of three network‐induced phenomena, namely, fading measurements, randomly varying nonlinearities and probabilistic distributed delays. The channel fading is characterized by the ?th‐order Rice fading model whose coefficients are mutually independent random variables with given probability density functions. Two sequences of random variables obeying the Bernoulli distribution are utilized to govern the randomly varying nonlinearities and probabilistic distributed delays. The purpose of the problem addressed is to design an state estimator such that the dynamics of the estimation errors is stochastically stable and the prespecified disturbance rejection attenuation level is guaranteed. Through intensive stochastic analysis, sufficient conditions are established under which the addressed state estimation problem is recast as a convex optimization one that can be solved via the semi‐definite program method. Finally, a simulation example is provided to show the usefulness of the proposed state estimation scheme. Copyright © 2014 John Wiley & Sons, Ltd.     

Awk — a pattern scanning and processing language

This paper describes the design and implementation of awk, a programming language which searches a set of files for patterns, and performs specified actions upon records or fields of records which match the patterns. Awk makes common data selection and transformation operations easy to express; for example, is a complete awk program that prints all input lines whose length exceeds 72 characters. The program prints each input line with the first field replaced by its logarithm. The program prints all lines in which the first field is different from the first field of the previous line. Patterns may include boolean combinations of regular expressions and of relational operators on strings, numbers, fields, variables, and array elements. Actions may include: the same matching constructions as in patterns; arithmetic and string expressions and assignments; if-else, while, and for statements; formatted output; and multiple output streams.     

A new dual‐mode wideband circularly polarized rectangular dielectric resonator antenna coupled with stubs and asymmetric ground plane for WiMAX applications

In this article, a new radiating stub microstrip feed has been investigated with asymmetrical ground plane for generation of circular polarization (CP) in a dielectric resonator antenna (DRA). Here, asymmetrical ground plane and 3 radiating stubs with microstrip feed line are used for generation of 2 different modes namely TE_11δ and TE_12δ in rectangular DRA. By using mode matching concepts, these modes are responsible for enhancing the impedance bandwidth (TE_12δ ie, and ) and axial ratio (AR) bandwidth (TE_11δ ie, and ) in proposed antenna. Designed antenna offers measured input impedance bandwidth (|S₁₁| < ?10 dB) and AR bandwidth (AR < 3‐dB) of 44.78%, ranging from 4.6 to 6.9 GHz and 23.32%, ranging from 4.6 to 6.9 GHz, respectively. It has been observed that proposed antenna shows left‐handed CP fields in boresight direction with average gain of 3.15 dBic and radiation efficiency of 90.54%. Designed antenna is suitable for Wi‐MAX (3.3‐3.7 GHz) applications.     

Weighted control with ‐stability constraint for switched positive linear systems

This paper is concerned with the problem of control with ‐stability constraint for a class of switched positive linear systems. The ‐stability means that all the poles of each subsystem of the resultant closed‐loop system belong to a prescribed disk in the complex plane. A sufficient condition is derived for the existence of a set of state‐feedback controllers, which guarantees that the closed‐loop system is not only positive and exponentially stable with each subsystem ‐stable but also has a weighted performance for a class of switching signals with average dwell time greater than a certain positive constant. Both continuous‐time and discrete‐time cases are considered, and all of the obtained conditions are formulated in terms of linear matrix inequalities, whose solution also yields the desired controller gains and the corresponding minimal average dwell time. Numerical examples are given to illustrate the effectiveness of the presented approach.Copyright © 2012 John Wiley & Sons, Ltd.     

SIMD Optimization of Linear Expressions for Programmable Graphics Hardware

The increased programmability of graphics hardware allows efficient graphical processing unit (GPU) implementations of a wide range of general computations on commodity PCs. An important factor in such implementations is how to fully exploit the SIMD computing capacities offered by modern graphics processors. Linear expressions in the form of , where A is a matrix, and and are vectors, constitute one of the most basic operations in many scientific computations. In this paper, we propose a SIMD code optimization technique that enables efficient shader codes to be generated for evaluating linear expressions. It is shown that performance can be improved considerably by efficiently packing arithmetic operations into four‐wide SIMD instructions through reordering of the operations in linear expressions. We demonstrate that the presented technique can be used effectively for programming both vertex and pixel shaders for a variety of mathematical applications, including integrating differential equations and solving a sparse linear system of equations using iterative methods.