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Robust
Kinds of Robust Terms modified by Robust Selected AbstractsExact and Robust (Self-)Intersections for Polygonal MeshesCOMPUTER GRAPHICS FORUM, Issue 2 2010Marcel Campen Abstract We present a new technique to implement operators that modify the topology of polygonal meshes at intersections and self-intersections. Depending on the modification strategy, this effectively results in operators for Boolean combinations or for the construction of outer hulls that are suited for mesh repair tasks and accurate mesh-based front tracking of deformable materials that split and merge. By combining an adaptive octree with nested binary space partitions (BSP), we can guarantee exactness (= correctness) and robustness (= completeness) of the algorithm while still achieving higher performance and less memory consumption than previous approaches. The efficiency and scalability in terms of runtime and memory is obtained by an operation localization scheme. We restrict the essential computations to those cells in the adaptive octree where intersections actually occur. Within those critical cells, we convert the input geometry into a plane-based BSP-representation which allows us to perform all computations exactly even with fixed precision arithmetics. We carefully analyze the precision requirements of the involved geometric data and predicates in order to guarantee correctness and show how minimal input mesh quantization can be used to safely rely on computations with standard floating point numbers. We properly evaluate our method with respect to precision, robustness, and efficiency. [source] Highly avid, oligoclonal, early-differentiated antigen-specific CD8+ T cells in chronic HIV-2 infectionEUROPEAN JOURNAL OF IMMUNOLOGY, Issue 7 2010Aleksandra Leligdowicz Abstract HIV-1-specific CD8+ T cells are present in most HIV-1-infected people and play an important role in controlling viral replication, but the characteristics of an effective HIV-specific T-cell response are largely unknown. The majority of HIV-2-infected people behave as long-term non-progressors while those who progress to AIDS do so in a manner indistinguishable from HIV-1. A detailed study of HIV-2 infection may identify protective immune responses. Robust gag p26-specific T-cell responses are elicited during HIV-2 infection and correlate with control of viremia. In this study, we analyzed features of an HLA-B*3501-restricted T-cell response to HIV-2 p26 that may contribute to virus control. In contrast to HIV-1, HIV-2-specific T cells are at an early stage of differentiation (CD27+CD28+), a finding that relates directly to CD4+ T-cell levels and inversely to immune activation. The cells demonstrate IFN-, secretion, oligoclonal T-cell receptor V, gene segment usage, exceptional avidity and secretion of pro-inflammatory cytokines. Despite the potentially strong selection pressure imposed on the virus by these cells, there was no evidence of HIV-2 sequence evolution. We propose that in chronic HIV-2 infection, the maintenance of early-differentiated, highly avid CD8+ T cells could account for the non-progressive course of disease. Such responses may be desirable from an HIV vaccine. [source] Somatodendritic autoreceptor regulation of serotonergic neurons: dependence on l -tryptophan and tryptophan hydroxylase-activating kinasesEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 4 2005Rong-Jian Liu Abstract The somatodendritic 5-HT1A autoreceptor has been considered a major determinant of the output of the serotonin (5-HT) neuronal system. However, recent studies in brain slices from the dorsal raphe nucleus have questioned the relevance of 5-HT autoinhibition under physiological conditions. In the present study, we found that the difficulty in demonstrating 5-HT tonic autoinhibition in slice results from in vitro conditions that are unfavorable for sustaining 5-HT synthesis. Robust, tonic 5-HT1A autoinhibition can be restored by reinstating in vivo 5-HT synthesizing conditions with the initial 5-HT precursor l -tryptophan and the tryptophan hydroxylase co-factor tetrahydrobiopterin (BH4). The presence of tonic autoinhibition under these conditions was revealed by the disinhibitory effect of a low concentration of the 5-HT1A antagonist WAY 100635. Neurons showing an autoinhibitory response to l -tryptophan were confirmed immunohistochemically to be serotonergic. Once conditions for tonic autoinhibition had been established in raphe slice, we were able to show that 5-HT autoinhibition is critically regulated by the tryptophan hydroxylase-activating kinases calcium/calmodulin protein kinase II (CaMKII) and protein kinase A (PKA). In addition, at physiological concentrations of l -tryptophan, there was an augmentation of 5-HT1A receptor-mediated autoinhibition when the firing of 5-HT cells activated with increasing concentrations of the ,1 adrenoceptor agonist phenylephrine. Increased calcium influx at higher firing rates, by activating tryptophan hydroxylase via CaMKII and PKA, can work together with tryptophan to enhance negative feedback control of the output of the serotonergic system. [source] Autism-like behavioral phenotypes in BTBR T+tf/J miceGENES, BRAIN AND BEHAVIOR, Issue 2 2008H. G. McFarlane Autism is a behaviorally defined neurodevelopmental disorder of unknown etiology. Mouse models with face validity to the core symptoms offer an experimental approach to test hypotheses about the causes of autism and translational tools to evaluate potential treatments. We discovered that the inbred mouse strain BTBR T+tf/J (BTBR) incorporates multiple behavioral phenotypes relevant to all three diagnostic symptoms of autism. BTBR displayed selectively reduced social approach, low reciprocal social interactions and impaired juvenile play, as compared with C57BL/6J (B6) controls. Impaired social transmission of food preference in BTBR suggests communication deficits. Repetitive behaviors appeared as high levels of self-grooming by juvenile and adult BTBR mice. Comprehensive analyses of procedural abilities confirmed that social recognition and olfactory abilities were normal in BTBR, with no evidence for high anxiety-like traits or motor impairments, supporting an interpretation of highly specific social deficits. Database comparisons between BTBR and B6 on 124 putative autism candidate genes showed several interesting single nucleotide polymorphisms (SNPs) in the BTBR genetic background, including a nonsynonymous coding region polymorphism in Kmo. The Kmo gene encodes kynurenine 3-hydroxylase, an enzyme-regulating metabolism of kynurenic acid, a glutamate antagonist with neuroprotective actions. Sequencing confirmed this coding SNP in Kmo, supporting further investigation into the contribution of this polymorphism to autism-like behavioral phenotypes. Robust and selective social deficits, repetitive self-grooming, genetic stability and commercial availability of the BTBR inbred strain encourage its use as a research tool to search for background genes relevant to the etiology of autism, and to explore therapeutics to treat the core symptoms. [source] Cover Picture: Synthesis of Gadolinium-Labeled Shell-Crosslinked Nanoparticles for Magnetic Resonance Imaging Applications (Adv. Funct.ADVANCED FUNCTIONAL MATERIALS, Issue 8 2005Mater. Abstract Robust, amphiphilic core,shell nanoparticles that are selectively labeled with gadolinium in the hydrophilic and water-swollen shell layer are depicted in the cover picture. These well-defined nanostructured materials exhibit high relaxivity, a large loading capacity, and are based upon a biocompatible platform for ultimate function in magnetic resonance imaging (MRI) applications, as reported by Wooley and co-workers on p.,1248. Shell-crosslinked knedel-like nanoparticles (SCKs; "knedel" is a Polish term for dumplings) were derivatized with gadolinium chelates and studied as robust magnetic-resonance-imaging-active structures with hydrodynamic diameters of 40,±,3,nm. SCKs possessing an amphiphilic core,shell morphology were produced from the aqueous assembly of diblock copolymers of poly-(acrylic acid) (PAA) and poly(methyl acrylate) (PMA), PAA52,b,PMA128, and subsequent covalent crosslinking by amidation upon reaction with 2,2,-(ethylenedioxy)bis(ethylamine) throughout the shell layer. The properties of these materials, including non-toxicity towards mammalian cells, non-immunogenicity within mice, and capability for polyvalent targeting, make them ideal candidates for utilization within biological systems. The synthesis of SCKs derivatized with GdIII and designed for potential use as a unique nanometer-scale contrast agent for MRI applications is described herein. Utilization of an amino-functionalized diethylenetriaminepentaacetic acid,Gd analogue allowed for direct covalent conjugation throughout the hydrophilic shell layer of the SCKs and served to increase the rotational correlation lifetime of the Gd. In addition, the highly hydrated nature of the shell layer in which the Gd was located allowed for rapid water exchange; thus, the resulting material demonstrated large ionic relaxivities (39,s,1,mM,1) in an applied magnetic field of 0.47,T at 40,°C and, as a result of the large loading capacity of the material, also demonstrated high molecular relaxivities (20,000,s,1,mM,1). [source] Robust and Responsive Dendrimer,Gold Nanoparticle Nanocomposites via Dithiocarbamate CrosslinkingADVANCED MATERIALS, Issue 22 2009Myoung-Hwan Park A simple and reliable one-step technique is developed to form robust PAMAM dendrimer,gold nanoparticle nanocomposites using dithiocarbamate-based chemistry. The interparticle spacing and optical properties of films can be readily tuned by controlling the dendrimer generation and/or the mole ratio between dendrimers and nanoparticles. The technique is also used to obtain patterned materials on prepatterned surfaces. [source] Robust and direct evaluation of J2 in linear elastic fracture mechanics with the X-FEMINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 10 2008G. Legrain Abstract The aim of the present paper is to study the accuracy and the robustness of the evaluation of Jk -integrals in linear elastic fracture mechanics using the extended finite element method (X-FEM) approach. X-FEM is a numerical method based on the partition of unity framework that allows the representation of discontinuity surfaces such as cracks, material inclusions or holes without meshing them explicitly. The main focus in this contribution is to compare various approaches for the numerical evaluation of the J2 -integral. These approaches have been proposed in the context of both classical and enriched finite elements. However, their convergence and the robustness have not yet been studied, which are the goals of this contribution. It is shown that the approaches that were used previously within the enriched finite element context do not converge numerically and that this convergence can be recovered with an improved strategy that is proposed in this paper. Copyright © 2008 John Wiley & Sons, Ltd. [source] Robust and efficient domain decomposition preconditioners for adaptive hp finite element approximations of linear elasticity with and without discontinuous coefficientsINTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN ENGINEERING, Issue 3 2004Andrew C. Bauer Abstract Adaptive finite element methods (FEM) generate linear equation systems that require dynamic and irregular patterns of storage, access, and computation, making their parallelization difficult. Additional difficulties are generated for problems in which the coefficients of the governing partial differential equations have large discontinuities. We describe in this paper the development of a set of iterative substructuring based solvers and domain decomposition preconditioners with an algebraic coarse-grid component that address these difficulties for adaptive hp approximations of linear elasticity with both homogeneous and inhomogeneous material properties. Our solvers are robust and efficient and place no restrictions on the mesh or partitioning. Copyright © 2003 John Wiley & Sons, Ltd. [source] Robust, Conducting, and Transparent Polymer Composites Using Surface-Modified and Individualized Double-Walled Carbon Nanotubes,ADVANCED MATERIALS, Issue 23 2008Yong Chae Jung Double-walled carbon nanotubes (DWNTs), consisting of two concentric coaxial tubes, are proposed as the preferable reinforcing filler in polymers. Chemical moieties, which are selectively introduced on the outer tubes, impart the ability to individualize and provide effective anchoring sites for strong bonding with polymers, while the optical properties of the inner tubes of the DWNTs remain unchanged. [source] Robust ,, filtering for uncertain differential linear repetitive processesINTERNATIONAL JOURNAL OF ADAPTIVE CONTROL AND SIGNAL PROCESSING, Issue 3 2008Ligang Wu Abstract The unique characteristic of a repetitive process is a series of sweeps or passes through a set of dynamics defined over a finite duration known as the pass length. At the end of each pass, the process is reset and the next time through the output, or pass profile, produced on the previous pass acts as a forcing function on, and hence contributes to, the dynamics of the new pass profile. They are hence a class of systems where a variable must be expressed in terms of two directions of information propagation (from pass-to-pass and along a pass, respectively) where the dynamics over the finite pass length are described by a matrix linear differential equation and from pass to pass by a discrete updating structure. This means that filtering/estimation theory/algorithms for, in particular, 2D discrete linear systems is not applicable. In this paper, we solve a general robust filtering problem with a view towards use in many applications where such an action will be required. Copyright © 2007 John Wiley & Sons, Ltd. [source] Robust ,2 -gain feedforward control of uncertain systems using dynamic IQCsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 11 2009I. E. Köse Abstract We consider the problem of robust ,2 -gain disturbance feedforward control for uncertain systems described in the standard LFT form. We use integral quadratic constraints (IQCs) for describing the uncertainty blocks in the system. For technical reasons related to the feedforward problem, throughout the paper, we work with the duals of the constraints involved in robustness analysis using IQCs. We obtain a convex solution to the problem using a state-space characterization of nominal stability that we have developed recently. Specifically, our solution consists of LMI conditions for the existence of a feedforward controller that guarantees a given ,2 -gain for the closed-loop system. We demonstrate the effectiveness of using dynamic IQCs in robust feedforward design through a numerical example. Copyright © 2008 John Wiley & Sons, Ltd. [source] Robust and nonlinear control literature survey (No. 9)INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 18 2008Article first published online: 30 OCT 200 First page of article [source] Robust and efficient quantization and coding for control of multidimensional linear systems under data rate constraintsINTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 10-11 2007K. Li Abstract Recently, we reported results on coding strategies for scalar feedback systems with data-rate-limited feedback channels in which the data-rate constraints are time varying. Such rate-varying channels are typically encountered in communication networks in which links between nodes are subject to noise, congestion, and intermittent disruption. The present paper describes results of extending this research into the multidimensional domain. An important consideration is that for systems of dimension greater than one, many classical feedback designs cannot be realized for operation near the theoretical minimum possible data rate. A novel control coding scheme will be presented, and in terms of this, it will be shown that the advantages of coarse signal quantization that had been reported earlier for scalar systems remain in the multidimensional case. The key is to allocate the communication bandwidth efficiently among faster and slower modes. We discuss various strategies that allocate bandwidth by scheduling the time slots assigned to each mode. In particular, we propose a ,robust attention varying' technique, whose merit will be discussed in terms of its robustness with respect to time-varying communication channel capacity and also in terms of how well it operates when the feedback channel capacity is near the theoretical minimum data rate. Copyright © 2006 John Wiley & Sons, Ltd. [source] Robust ,, filtering for uncertain Markovian jump linear systems,INTERNATIONAL JOURNAL OF ROBUST AND NONLINEAR CONTROL, Issue 5 2002Carlos E. de Souza Abstract This paper investigates the problem of ,, filtering for a class of uncertain Markovian jump linear systems. The uncertainty is assumed to be norm-bounded and appears in all the matrices of the system state-space model, including the coefficient matrices of the noise signals. It is also assumed that the jumping parameter is available. We develop a methodology for designing a Markovian jump linear filter that ensures a prescribed bound on the ,2 -induced gain from the noise signals to the estimation error, irrespective of the uncertainty. The proposed design is given in terms of linear matrix inequalities. Copyright © 2002 John Wiley & Sons, Ltd. [source] Insights into the Role of New Palladium Pincer Complexes as Robust and Recyclable Precatalysts for Suzuki,Miyaura Couplings in Neat WaterADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 13 2009Blanca Inés Abstract Suzuki,Miyaura biaryl and diarylmethane syntheses via the coupling of arylboronic acids with aryl and arylmethyl bromides are performed in water by means of two new CNC-type palladium pincer complexes. Good to excellent results (including high TON values and extended recycling procedures) are obtained in most cases for a range of electronically dissimilar halides and boronic acids. On the basis of a series of kinetics studies, transmission electron microscopy (TEM), mercury drop tests, and quantitative poisoning experiments, the real role of the latter palladacycles, closely linked to the formation and active participation of palladium nanoparticles, is discussed. [source] Generation and visualization of large-scale three-dimensional reconstructions from underwater robotic surveysJOURNAL OF FIELD ROBOTICS (FORMERLY JOURNAL OF ROBOTIC SYSTEMS), Issue 1 2010Matthew Johnson-Roberson Robust, scalable simultaneous localization and mapping (SLAM) algorithms support the successful deployment of robots in real-world applications. In many cases these platforms deliver vast amounts of sensor data from large-scale, unstructured environments. These data may be difficult to interpret by end users without further processing and suitable visualization tools. We present a robust, automated system for large-scale three-dimensional (3D) reconstruction and visualization that takes stereo imagery from an autonomous underwater vehicle (AUV) and SLAM-based vehicle poses to deliver detailed 3D models of the seafloor in the form of textured polygonal meshes. Our system must cope with thousands of images, lighting conditions that create visual seams when texturing, and possible inconsistencies between stereo meshes arising from errors in calibration, triangulation, and navigation. Our approach breaks down the problem into manageable stages by first estimating local structure and then combining these estimates to recover a composite georeferenced structure using SLAM-based vehicle pose estimates. A texture-mapped surface at multiple scales is then generated that is interactively presented to the user through a visualization engine. We adapt established solutions when possible, with an emphasis on quickly delivering approximate yet visually consistent reconstructions on standard computing hardware. This allows scientists on a research cruise to use our system to design follow-up deployments of the AUV and complementary instruments. To date, this system has been tested on several research cruises in Australian waters and has been used to reliably generate and visualize reconstructions for more than 60 dives covering diverse habitats and representing hundreds of linear kilometers of survey. © 2009 Wiley Periodicals, Inc. [source] ,Robust and Raring to Go?', Judges' Perceptions of Child WitnessesJOURNAL OF LAW AND SOCIETY, Issue 4 2007Fiona E. Raitt This article explores judicial perceptions of child witnesses. It considers the impact of recent legislation in England and Wales as well as in Scotland which classified all child witnesses as vulnerable and introduced a series of special measures to facilitate children's evidence. The article reports the findings of an empirical research study conducted with the judiciary in Scotland which suggests that judicial perceptions of child witnesses extend across a complex spectrum where a child may be viewed as vulnerable but is also likely to be seen as suggestible, reliable or resilient. The article advances two propositions. First, that the statutory conceptualization of children as invariably vulnerable has not displaced established beliefs concerning children's suggestibility and therefore has made little difference to perceptions of their ability to produce reliable testimony. Second, that focusing on children's potential for resilience rather than their vulnerability may prove a more productive conceptualization of children, one which could better support their capability as witnesses. [source] Kinetics of cytomegalovirus (CMV) pp65 and IE-1-specific IFN, CD8+ and CD4+ T cells during episodes of viral DNAemia in allogeneic stem cell transplant recipients: Potential implications for the management of active CMV infectionJOURNAL OF MEDICAL VIROLOGY, Issue 7 2010Nuria Tormo Abstract The dynamics of CMV pp65 and IE-1-specific IFN,-producing CD8+ (IFN, CD8+) and CD4+ (IFN, CD4+) T cells and CMV DNAemia were assessed in 19 pre-emptively treated episodes of active CMV infection. Peripheral counts of IFN, CD8+ and IFN, CD4+ T cells inversely correlated with CMV DNAemia levels (P,=,<0.001 and P,=,0.003, respectively). A threshold value of 1.3,cells/µl predicting CMV DNAemia clearance was established for IFN, CD8+ T cells (PPV, 100%; NPV, 93%) and for IFN, CD4+ T cells (PPV, 100%; NPV, 75%). Undetectable T-cell responses were usually observed at the time of initiation of pre-emptive therapy. Either a rapid (within 7 days) or a delayed (median 31 days) expansion of both T-cell populations concomitant with CMV DNAemia clearance was observed in 5 and 8 episodes, respectively. An inconsistent or a lack of expansion of both T-cell subsets was related to a persistent CMV DNAemia. Robust and maintained CMV-specific T-cell responses after CMV DNAemia clearance and cessation of antiviral therapy were associated with a null incidence of relapsing infections at least during the following month. Data obtained in the present study may be helpful in the design of therapeutic strategies for the management of active CMV infections in the allo-SCT recipient. J. Med. Virol. 82: 1208,1215, 2010. © 2010 Wiley-Liss, Inc. [source] Range Unit-Root (RUR) Tests: Robust against Nonlinearities, Error Distributions, Structural Breaks and OutliersJOURNAL OF TIME SERIES ANALYSIS, Issue 4 2006Felipe Aparicio Abstract., Since the seminal paper by Dickey and Fuller in 1979, unit-root tests have conditioned the standard approaches to analysing time series with strong serial dependence in mean behaviour, the focus being placed on the detection of eventual unit roots in an autoregressive model fitted to the series. In this paper, we propose a completely different method to test for the type of long-wave patterns observed not only in unit-root time series but also in series following more complex data-generating mechanisms. To this end, our testing device analyses the unit-root persistence exhibited by the data while imposing very few constraints on the generating mechanism. We call our device the range unit-root (RUR) test since it is constructed from the running ranges of the series from which we derive its limit distribution. These nonparametric statistics endow the test with a number of desirable properties, the invariance to monotonic transformations of the series and the robustness to the presence of important parameter shifts. Moreover, the RUR test outperforms the power of standard unit-root tests on near-unit-root stationary time series; it is invariant with respect to the innovations distribution and asymptotically immune to noise. An extension of the RUR test, called the forward,backward range unit-root (FB-RUR) improves the check in the presence of additive outliers. Finally, we illustrate the performances of both range tests and their discrepancies with the Dickey,Fuller unit-root test on exchange rate series. [source] Multiband multislice GE-EPI at 7 tesla, with 16-fold acceleration using partial parallel imaging with application to high spatial and temporal whole-brain fMRI,MAGNETIC RESONANCE IN MEDICINE, Issue 5 2010Steen Moeller Abstract Parallel imaging in the form of multiband radiofrequency excitation, together with reduced k -space coverage in the phase-encode direction, was applied to human gradient echo functional MRI at 7 T for increased volumetric coverage and concurrent high spatial and temporal resolution. Echo planar imaging with simultaneous acquisition of four coronal slices separated by 44mm and simultaneous 4-fold phase-encoding undersampling, resulting in 16-fold acceleration and up to 16-fold maximal aliasing, was investigated. Task/stimulus-induced signal changes and temporal signal behavior under basal conditions were comparable for multiband and standard single-band excitation and longer pulse repetition times. Robust, whole-brain functional mapping at 7 T, with 2 × 2 × 2mm3 (pulse repetition time 1.25 sec) and 1 × 1 × 2mm3 (pulse repetition time 1.5 sec) resolutions, covering fields of view of 256 × 256 × 176mm3 and 192 × 172 × 176mm3, respectively, was demonstrated with current gradient performance. Magn Reson Med 63:1144,1153, 2010. © 2010 Wiley-Liss, Inc. [source] QD technology and market prospects in the sectors of space exploration, biomedicine, defense, and securityPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2008C. A. Charitidis Abstract Quantum dots (QD) are a unique subset of nanomaterials characterized by their extraordinary quantum confinement behaviour. Even though the quantum dot industry is still in its infancy with revenues now reaching $10 million, it is expected to surpass $500 million in 2009. However, in order to leverage the full potential of the QD technology, new fabrication processes must be developed to attain high detectivity and high operating temperature (HOT) photodetector devices. The Quantum Dot Infrared Photodetectors (QDIPs) possess an immense potential for civilian and military applications due to the distinct characteristics stemming from their dimensionality , which provides 3D carrier confinement and the capacity for normal-incidence detection , and their amenability to bandgap engineering , which allows tailoring the peak and cutoff wavelengths according to custom needs. The QDIPs, especially when optimized to operate at higher temperatures, can become critical components in space exploration, defence and security, optical communication, quantum computing and cryptography, and medical imaging applications. Robust and reliable solutions for these fields will command a premium position in the marketplace as by responding to the societal need for secure electronic transactions, exponentially faster data processing, and higher quality diagnostic tools. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Are Momentum Profits Robust to Trading Costs?THE JOURNAL OF FINANCE, Issue 3 2004Robert A. Korajczyk We test whether momentum strategies remain profitable after considering market frictions induced by trading. Intraday data are used to estimate alternative measures of proportional and non-proportional (price impact) trading costs. The price impact models imply that abnormal returns to portfolio strategies decline with portfolio size. We calculate break-even fund sizes that lead to zero abnormal returns. In addition to equal- and value-weighted momentum strategies, we derive a liquidity-weighted strategy designed to reduce the cost of trades. Equal-weighted strategies perform the best before trading costs and the worst after trading costs. Liquidity-weighted and hybrid liquidity/value-weighted strategies have the largest break-even fund sizes: $5 billion or more (relative to December 1999 market capitalization) may be invested in these momentum strategies before the apparent profit opportunities vanish. [source] Robust l2,l, state feedback control for uncertain discrete-time switched systems with mode-dependent time-varying delays,ASIAN JOURNAL OF CONTROL, Issue 4 2010Guangdeng Zong Abstract This paper deals with the problem of robust l2,l, state feedback control for uncertain discrete-time switched systems with mode-dependent time-varying delays. Attention is focused on the design of a switched state feedback controller, which guarantees the asymptotical stability of the closed-loop system and reduces the effect of the disturbance input on the controlled output to a prescribed level for all admissible uncertainties. By resorting to a descriptor system approach, delay-dependent sufficient conditions are presented in terms of linear matrix inequalities (LMIs). A numerical example is provided to demonstrate the effectiveness of the proposed algorithms. Copyright © 2010 John Wiley and Sons Asia Pte Ltd and Chinese Automatic Control Society [source] ChemInform Abstract: Fe3O4 Nanoparticles: A Robust and Magnetically Recoverable Catalyst for Three-Component Coupling of Aldehyde, Alkyne and Amine.CHEMINFORM, Issue 34 2010Tieqiang Zeng No abstract is available for this article. [source] ChemInform Abstract: Air-Tolerant C,C Bond Formation via Organometallic Ruthenium Catalysis: Diverse Catalytic Pathways Involving (C5Me5)Ru or (C5H5)Ru Are Robust to Molecular Oxygen.CHEMINFORM, Issue 45 2009Lukas Severa Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Air-Tolerant C,C Bond Formation via Organometallic Ruthenium Catalysis: Diverse Catalytic Pathways Involving (C5Me5)Ru or (C5H5)Ru Are Robust to Molecular Oxygen.CHEMINFORM, Issue 45 2009Lukas Severa Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Development of a Robust and Practical Process for the Darzens Condensation and ,,,-Epoxide Rearrangement: Scope and Limitations of the Methodology.CHEMINFORM, Issue 34 2008Jeremy Malcolm Zimbron Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Light-Fluorous Safety-Catch Arylgermanes , Exceptionally Robust, Photochemically Activated Precursors for Biaryl Synthesis by Pd(0)-Catalyzed Cross-Coupling.CHEMINFORM, Issue 46 2007Alan C. Spivey Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Controlling Peptide Structure with Coordination Chemistry: Robust and Reversible Peptide,Dirhodium LigationCHEMISTRY - A EUROPEAN JOURNAL, Issue 36 2009Alexander Mild and reversible: A dirhodium tetracarboxylate reacts with peptides to bridge carboxylate side chains (see scheme). The ligation proceeds under mild aqueous conditions and is readily reversible. Dirhodium adduct formation can be used to control the conformation and supramolecular structure of peptides. [source] Towards Supramolecular Fixation of NOX Gases: Encapsulated Reagents for NitrosationCHEMISTRY - A EUROPEAN JOURNAL, Issue 6 2005Yanlong Kang Abstract The use of simple calix[4]arenes for chemical conversion of NO2/N2O4 gases is demonstrated in solution and in the solid state. Upon reacting with these gases, calixarenes 1 encapsulate nitrosonium (NO+) cations within their cavities with the formation of stable calixarene,NO+ complexes 2. These complexes act as encapsulated nitrosating reagents; cavity effects control their reactivity and selectivity. Complexes 2 were effectively used for nitrosation of secondary amides 5, including chiral derivatives. Unique size,shape selectivity was observed, allowing for exclusive nitrosation of less crowded N -Me amides 5,a,e (up to 95,% yields). Bulkier N -Alk (Alk>Me) substrates 5 did not react due to the hindered approach to the encapsulated NO+ reagents. Robust, silica gel based calixarene material 3 was prepared, which reversibly traps NO2/N2O4 with the formation of NO+ -storing silica gel 4. With material 4, similar size,shape selectivity was observed for nitrosation. The N -Me,N -nitroso derivatives 6,d,e were obtained with ,30,% yields, while bulkier amides were nitrosated with much lower yields (<8,%). Enantiomerically pure encapsulating reagent 2,d was tested for nitrosation of racemic amide 5,t, showing modest but reproducible stereoselectivity and ,15,% ee. Given high affinity to NO+ species, which can be generated by a number of NOX gases, these supramolecular reagents and materials may be useful for NOX entrapment and separation in the environment and biomedical areas. [source] | |||||||||||||||||||||||||||||||||||||||||||||||||||||||