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Electronic Systems (electronic + system)
Selected AbstractsUsing a PCT-wide electronic system called the Deadly Trio databaseÔ to provide safety alerts about prescribing of metformin in renal diseaseDIABETIC MEDICINE, Issue 10 2010A. C. Burden No abstract is available for this article. [source] Approximate lower bounds of the Weinstein and Temple varietyINTERNATIONAL JOURNAL OF QUANTUM CHEMISTRY, Issue 6 2007M. G. Marmorino Abstract By using the Weinstein interval or coupling the Temple lower bound to a variational upper bound one can in principle construct an error bar about the ground-state energy of an electronic system. Unfortunately there are theoretical and calculational issues which complicate this endeavor so that at best only an upper bound to the electronic energy has been practical in systems with more than a few electrons. The calculational issue is the complexity of ,H2, which is necessary in the Temple or Weinstein approach. In this work we provide a way to approximate the ,H2, to any desired accuracy using much simpler ,H,-like information so that the lower bound calculations are more practical. The helium atom is used as a testing ground in which we obtain approximate error bars for the ground-state energy of [,2.904230, ,2.903721] hartree using the variational energy with the Temple lower bound and [,2.919098, ,2.888344] hartree for the Weinstein interval. For comparison, the slightly larger error bars using the exact value of ,H2, are: [,2.904358, ,2.903721] hartree and [,2.919765, ,2.887677] hartree, respectively. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2007 [source] Report of the Editor-in-ChiefJOURNAL OF AGRICULTURAL ECONOMICS, Issue 1 2006David Harvey Summary 2005 has been a year of transition for the Journal , the editorial management was transferred from Nottingham to the team at Newcastle, we moved to Blackwell Publishing, and the management of the editorial process was moved from a paper-based system to an electronic system and then, in January 2006, to an on-line submission and web-based management system under Manuscript Central by ©ScholarOne. Submissions to the Journal increased during 2005, though we published rather fewer papers (22) than in recent years. We continue to improve the average turnround time between submission and first decision, reaching 3 months in 2005. Our ISI citation ranking continues to be disappointing, but we will continue to publish the very best of our submissions, and maintain the well-established quality of JAE. [source] Atom Transfer Radical Polymerization and Third-Order Nonlinear Optical Properties of New Azobenzene-Containing Side-Chain PolymersMACROMOLECULAR CHEMISTRY AND PHYSICS, Issue 4 2007Najun Li Abstract The atom transfer radical polymerization (ATRP) technique has been successfully applied to synthesize a series of nonlinear optically (NLO) active homopolymers, 4-(4-nitrophenyl-diazenyl) phenyl acrylate (P - NPAPA) and 4-(4-methoxyphenyl-diazenyl) phenyl acrylate (P - MPAPA), containing azobenzene groups on the side chain. The third-order NLO properties of the polymer films were measured by the degenerated four-wave mixing (DFWM) technique. A dependence of the ,(3) values and response times of polymers on their number-average molecular weight and the electronic effect of the substituent (nitro- or methoxy-) on the azobenzene group have been evidenced. The increasing ,(3) value of the polymer films at the magnitude of about 10,10 was displayed with increasing molecular weight and the presence of the push-pull electronic system contributes much in enhancing the third-order NLO susceptibility of polymers. [source] The dressed nonrelativistic electron in a magnetic fieldMATHEMATICAL METHODS IN THE APPLIED SCIENCES, Issue 10 2006Laurent Amour Abstract We consider a nonrelativistic electron interacting with a classical magnetic field pointing along the x3 -axis and with a quantized electromagnetic field. When the interaction between the electron and photons is turned off, the electronic system is assumed to have a ground state of finite multiplicity. Because of the translation invariance along the x3 -axis, we consider the reduced Hamiltonian associated with the total momentum along the x3 -axis and, after introducing an ultraviolet cutoff and an infrared regularization, we prove that the reduced Hamiltonian has a ground state if the coupling constant and the total momentum along the x3 -axis are sufficiently small. We determine the absolutely continuous spectrum of the reduced Hamiltonian and, when the ground state is simple, we prove that the renormalized mass of the dressed electron is greater than or equal to its bare one. We then deduce that the anomalous magnetic moment of the dressed electron is nonnegative. Copyright © 2006 John Wiley & Sons, Ltd. [source] Hartree,Fock interactions in the integer quantum Hall effectPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 2 2008Rudolf A. Römer Abstract We report on numerical studies into the interplay of disorder and electron,electron interactions within the integer quantum Hall regime, where the presence of a strong magnetic field and two-dimensional confinement of the electronic system profoundly affects thermodynamic and transport properties. We emphasise the behaviour of the electronic compressibility, the local density of states, and the Kubo conductivity. Our treatment of the electron,electron interactions relies on the Hartree-Fock approximation so as to achieve system sizes comparable to experimental situations. Our results clearly exhibit manifestations of various interaction-mediated features, such as non-linear screening, local charging, and g -factor enhancement, implying the inadequacy of independent-particle models for comparison with experimental results. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Low-temperature electrical conductivity of heavily boron-doped diamond single crystalsPHYSICA STATUS SOLIDI (B) BASIC SOLID STATE PHYSICS, Issue 1 2007V. D. Blank Abstract Single crystal diamonds 0.2,0.7 cm large doped with boron concentration 1019,1020 cm,3 were grown by temperature gradient method on the seed under pressure P = 5.5 GPa, temperature T = 1650 K. Temperature dependence of electrical resistance had been measured in the range of 0.5,297 K. Boltzmann activation type of conductivity and Mott's VRH law observed in samples in the temperature ranges ,200,297 K and ,70,297 K respectively. The temperature rise of conductivity in the range of ,0.5,50 K for most heavily doped crystals was proportional to T1/2. This rule indicates the vicinity of the electronic system to metal,insulator transition. (© 2007 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Controlled Synthesis of CdSe Nanowires by Solution,Liquid,Solid MethodADVANCED FUNCTIONAL MATERIALS, Issue 22 2009Zhen Li Abstract Semiconductor nanowires prepared by wet chemical methods are a relatively new field of 1D electronic systems, where the dimensions can be controlled by changing the reaction parameters using solution chemistry. Here, the solution,liquid,solid approach where the nanowire growth is governed by low-melting-point catalyst particles, such as Bi nanocrystals, is presented. In particular, the focus is on the preparation and characterization of CdSe nanowires, a material which serves a prototype structure for many kinds of low dimensional semiconductor systems. To investigate the influence of different reaction parameters on the structural and optical properties of the nanowires, a comprehensive synthetic study is presented, and the results are compared with those reported in literature. How the interplay between different reaction parameters affects the diameter, length, crystal structure, and the optical properties of the resultant nanowires are demonstrated. The structural properties are mainly determined by competing reaction pathways, such as the growth of Bi nanocatalysts, the formation and catalytic growth of nanowires, and the formation and uncatalytic growth of quantum dots. Systematic variation of the reaction parameters (e.g., molecular precursors, concentration and concentration ratios, organic ligands, or reaction time, and temperature) enables control of the nanowire diameter from 6 to 33,nm, while their length can be adjusted between several tens of nanometers and tens of micrometers. The obtained CdSe nanowires exhibit an admixture of wurtzite (W) and zinc blende (ZB) structure, which is investigated by X-ray diffraction. The diameter-dependent band gaps of these nanowires can be varied between 650 and 700,nm while their fluorescence intensities are mainly governed by the Cd/Se precursor ratio and the ligands used. [source] Analog circuit design by nonconvex polynomial optimization: Two design examplesINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 1 2010Siu-Hong Lui Abstract We present a framework for synthesizing low-power analog circuits through global optimization over generally nonconvex multivariate polynomial objective function and constraints. Specifically, a nonconvex optimization problem is formed, which is then efficiently solved through convex programming techniques based on linear matrix inequality (LMI) relaxation. The framework allows both polynomial inequality and equality constraints, thereby facilitating more accurate device modelings and parameter tuning. Compared to traditional nonlinear programming (NLP), the proposed methodology exhibits superior computational efficiency, and guarantees convergence to a globally optimal solution. As in other physical design tasks, circuit knowledge and insight are critical for initial problem formulation, while the nonconvex optimization machinery provides a versatile tool and systematic way to locate the optimal parameters meeting design specifications. Two circuit design examples are given, namely, a nested transconductance(Gm),capacitance compensation (NGCC) amplifier and a delta,sigma (,,) analog-to-digital converter (ADC), both of them being the key components in many electronic systems. Copyright © 2008 John Wiley & Sons, Ltd. [source] On models of fractal networksINTERNATIONAL JOURNAL OF CIRCUIT THEORY AND APPLICATIONS, Issue 5 2009Walter Arrighetti Abstract A couple of iterative models for the theoretical study of fractal networks whose topologies are generated via iterated function systems is presented: a lumped-parameter impedor-oriented one and a two-port-network-oriented one. With the former, the voltage and current patterns give a detailed understanding of the electromagnetic fields' self-similar distribution throughout the network; on the other hand, model complexity exponentially increases with the prefractal iteration order. The latter ,black-box' model only controls port-oriented global parameters that are the ones commonly used in the integration of different electronic systems, and its complexity is independent of prefractal order. Sierpinski gasket and carpet topologies are reported as examples. Copyright © 2008 John Wiley & Sons, Ltd. [source] Optimization of a finned heat sink array based on thermoeconomic analysisINTERNATIONAL JOURNAL OF ENERGY RESEARCH, Issue 5 2007S. Z. Shuja Abstract The design and specification of heat sinks for electronic systems is not easily accomplished through the use of standard thermal design and analysis tools since geometric and boundary conditions are not typically known in advance. A second-law based thermoeconomic optimization procedure is presented for a finned heat sink array. This involves including costs associated with material, and irreversible losses due to heat transfer and pressure drop. The influence of important physical, geometrical and unit cost parameters on the overall finned array are optimized for some typical operating conditions that are representative of electronic cooling applications. The optimized cost results are presented in terms of ReD, ReL, ,P / ,H, and q for a finned system in a graphical form. In addition the methodology of obtaining optimum parameters for a finned heat sink system which will result in minimum operating cost is demonstrated. Copyright © 2006 John Wiley & Sons, Ltd. [source] Role of the temperature distribution on the PN junction behaviour in the electro-thermal simulationINTERNATIONAL JOURNAL OF NUMERICAL MODELLING: ELECTRONIC NETWORKS, DEVICES AND FIELDS, Issue 6 2004Hatem Garrab Abstract Electro-thermal simulations of a PIN-diode based on the finite-element method, show a non-uniform temperature distribution inside the device during switching transients. Hence, the implicit assumption of a uniform temperature distribution when coupling an analytical electrical model and a thermal model yields inaccurate electro-thermal behaviour of the PIN-diode so far. The idea of including non-uniform temperature distribution into power semiconductor device models is not new, as accurate electro-thermal simulations are required for designing compact power electronic systems (as IC or MCM). Instead of using a one-dimensional finite difference or element method, the bond graphs and the hydrodynamic method are utilized to build an electro-thermal model of the PIN-diode. The results obtained by this original technique are compared with those obtained by a commercial finite-element simulator. The results are similar but the computation effort of the proposed technique is a fraction of that required by finite-element simulators. Moreover, the proposed technique may be applied easily to other power semiconductor devices. Copyright © 2004 John Wiley & Sons, Ltd. [source] Perceptions of Effective and Ineffective Nurse,Physician Communication in HospitalsNURSING FORUM, Issue 3 2010F. Patrick Robinson PhD PROBLEM., Nurse,physician communication affects patient safety. Such communication has been well studied using a variety of survey and observational methods; however, missing from the literature is an investigation of what constitutes effective and ineffective interprofessional communication from the perspective of the professionals involved. The purpose of this study was to explore nurse and physician perceptions of effective and ineffective communication between the two professions. METHODS., Using focus group methodology, we asked nurses and physicians with at least 5 years' acute care hospital experience to reflect on effective and ineffective interprofessional communication and to provide examples. Three focus groups were held with 6 participants each (total sample 18). Sessions were audio recorded and transcribed verbatim. Transcripts were coded into categories of effective and ineffective communication. FINDINGS., The following themes were found. For effective communication: clarity and precision of message that relies on verification, collaborative problem solving, calm and supportive demeanor under stress, maintenance of mutual respect, and authentic understanding of the unique role. For ineffective communication: making someone less than, dependence on electronic systems, and linguistic and cultural barriers. CONCLUSION., These themes may be useful in designing learning activities to promote effective interprofessional communication. [source] The prescribed duration algorithm: utilising ,free text' from multiple primary care electronic systemsPHARMACOEPIDEMIOLOGY AND DRUG SAFETY, Issue 9 2010Caroline J. Brooks Abstract Purpose To develop and test an algorithm that translates total dose and daily regimen, inputted as ,free text' on a prescription, into numerical values to calculate the prescribed treatment duration. Method The algorithm was developed using antibiotic prescriptions (n,=,711,714) from multiple primary care computer systems. For validation, the prescribed treatment duration of an independent sample of antibiotic scripts was calculated in two ways: (a) computer algorithm, (b) manually reviewed by a researcher blinded to the results of (a). The outputs of the two methods were compared and the level of agreement assessed, using confidence intervals for differences in proportions. This was repeated on sample of antidepressant scripts to test generalisabilty of the algorithm. Results For the antibiotic prescriptions, the algorithm processed 98.5% with an accuracy of 99.8% and the manual review processed 98.5% with 98.9% accuracy. The differences between these proportions are 0.0% (95%CI of ,0.9, 0.9%) and 1.0% (95%CI of ,0.1, 2.3%), respectively. For the antidepressant prescriptions, the algorithm processed 91.5% with an accuracy of 96.6% compared to the manual review with 96.4% processed and 99.8% accuracy; difference between these proportions is 4.9% (95%CI of 2.0, 8.0%) and 3.2% (95%CI of 1.6, 5.3%), respectively. Conclusion The algorithm proved to be applicable and efficient for assessing prescribed duration, with sensitivity and specificity values close to the manual review, but with the added advantage that the computer can process large volume of scripts rapidly and automatically. Copyright © 2010 John Wiley & Sons, Ltd. [source] Design of electronic systems based on functional capabilityQUALITY AND RELIABILITY ENGINEERING INTERNATIONAL, Issue 1 2008James M. Gilbert Abstract An important measure of design quality is the extent to which a circuit design is able to meets its specification in the presence of component parameter variations. Of equal importance is knowing how to improve this capability most effectively. This paper presents an analysis technique and visualization method which give the designer information about design quality and possible routes to improved quality. The paper introduces two new measures of functional capability, based on the process capability measure Cpk, and shows how these may be linked to the statistical variations in individual component parameters. It then shows how this information may be used to assess the effectiveness of altering the nominal value and variability in each of the component parameters in order to improve circuit performance capability. The analysis required is straightforward and the information is presented in a clear manner which can readily be interpreted by the designer. The effectiveness of the technique has been evaluated through analysis of a number of printed circuit board level analogue and mixed signal circuits and the results of a case study are shown. Copyright © 2007 John Wiley & Sons, Ltd. [source] Reversing the lead, or a series of unfortunate events?THE JOURNAL OF FUTURES MARKETS, Issue 12 2009Amaranth, NYMEX A number of studies compare the efficiency and transparency of floor trading with automated/electronic trading systems in the competition for order flow. Although most of these studies find that electronic systems lead price discovery, a few studies highlight the weaknesses of electronic trading in highly volatile market conditions. A series of unusual events in 2006, sparking extreme volatility in natural gas futures trading, provide an ideal setting to revisit the resilience of trading system price leadership in the face of high volatility. We estimate time-varying Hasbrouck-style information shares to investigate the intertemporal and cross-sectional dynamics in price discovery. The results strongly suggest that the information share is time-dependent and contract-dependent. Floor trading dominates price discovery in the less liquid longer-maturity contracts, whereas electronic trading dominates price discovery in the most liquid spot-month contract. We find that the floor trading information share increases significantly with realized volatility. © 2009 Wiley Periodicals, Inc. Jrl Fut Mark 29:1130,1160, 2009 [source] | |||||||||||||||||||