Layout design of manufacturable quantum-dot cellular automata

Quantum-dot cellular automaton (QCA) is an emergent technology that is not hindered by quantum effects that limit the scaling of CMOS technology, but instead employs them to perform computation. However, this brings its own impediments, such as the influence of the thermodynamic effects. Beside that, QCA has to be coupled with CMOS circuitry of different size features to enable clocking. We discussed all these facts and devised a floorplan which would facilitate manufacturability. Based on it we developed the process of QCA layout design and defined the design rules that must be considered in order to ensure correct operation. These instructions enable the automatization of designing a QCA circuit layout.     

Reconfigurable digital controller for a buck converter based on FPGA

This paper presents a complete digitally controlled dc–dc buck converter performed by FPGA circuitry. All tasks, analog to digital conversion, control algorithm and pulse width modulation, were implemented in the FPGA. This approach enables high-speed dynamic response and programmability by the controller, without external passive components. In addition, the controller’s structure can be easily changed without external components. The applied algorithm enables a switching frequency of 100 kHz.     

Impedance of blocking electrodes having parallel cylindrical pores with distributed radii

The impedance of blocking porous electrodes having parallel cylindrical pores with a lognormal distribution of their radii, identical pore depth and identical pore volume is calculated. Electrodes with size distribution of variable width, defined by different standard deviation (σ) values, are compared. The effect of varying σ is illustrated for the following cases: (i) the number of pores per unit surface (n) varies with σ while the median of the pore radius distribution (r_μ) remains constant; (ii) r_μ varies with σ while n remains constant; (iii) both n and r_μ vary with σ. It is shown that, although the general shape of the impedance plots is similar in all cases, the assumptions concerning n and r_μ have a major effect on the calculated frequency dependence. All impedance plots exhibit porous behaviour at high frequency and capacitive behaviour at low frequency, the transition being smoother for larger σ values. However, the frequency around which the porous-to-capacitive transition occurs depends on the additional assumptions: it increases as σ increases in cases (i) and (ii) but, in accordance with other authors’ calculations, decreases as σ increases for case (iii).     

An improved analysis of the potential drop method for measuring crack lengths in compact tension specimens

A single-parameter logarithmic equation is suggested for the calibration of the potential drop method for measuring crack length in compact tension specimens. This equation follows the correct asymptotic solution for long crack lengths and is shown to hold for even very short crack lengths for specimens with a small notch. Use of this equation provides a first step towards evaluation of calibration fata for anomalies such as those associated with variation of electrical conductivity due to plasticity of the crack tip and with uneven crack growth. In addition, use of this equation as a two-parameter model allows determination of the electrical resistivity of the specimen from the calibration data. Data are presented for specimens with large notches which support the results obtained in a previous paper by a numerical method coupled with conformal mapping.

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Résumé On suggère une équation logarithmique à paramètre simple pour l'étalonnage de la méthode de la chute potentielle, applicable à la mesure des longueurs de fissure dans des éprouvettes de traction compactes. Cette équation est conforme à la solution asymptotique correcte pour les fissures longues, et on montre qu'elle est applicable même pour des fissures très courtes dans la cas d'éprouvette comportant une petite entaille.L'utilisation de cette équation permet l'évaluation des données d'étalonnage dans le cas d'anomalies telles que celles qui sont associées à une variation de la conductibilité électrique due à la plasticité à l'extrémité de la fissure, et en présence d'une croissance inégale de celle-ci.En outre, l'utilisation de cette équation comme modèle à deux paramètres permet la détermination de la résistivité électrique d'une éprouvette au départ de données d'étalonnage.Des données sont présentées pour des éprouvettes à grande entaille. Elles viennen àa l'appui des résultats obtenus dans un article précédant par une méthode numérique associée à une représentation conforme.

     

An integrated approach to electrochemical impedance spectroscopy

A philosophy for electrochemical impedance spectroscopy is presented which integrates experimental observation, model development, and error analysis. This approach is differentiated from the usual sequential model development for given impedance spectra by its emphasis on obtaining supporting observations to guide model selection, use of error analysis to guide regression strategies and experimental design, and use of models to guide selection of new experiments. These concepts are illustrated with two examples taken from the literature. This work illustrates that selection of models, even those based on physical principles, requires both error analysis and additional experimental verification.     

Analysis of flooding as a stochastic process in polymer electrolyte membrane (PEM) fuel cells by impedance techniques

Impedance measurements were conducted to gain insight into flooding of a single polymer electrolyte membrane (PEM) fuel cell. The stochastic character of the formation of water droplets and subsequent removal by gas flow is demonstrated to increase the standard deviation of impedance measurements, yielding a sensitive manner to detect onset of flooding. The increase in stochastic noise associated with flooding was more apparent at low frequencies, due to the closer match to the characteristic frequency associated with the growth and removal of water droplets. The onset of flooding was sensitive to the design of the gas diffusion layer.     

Application of the SUSAN filter to wavelet video-coding artifact removal

This paper proposes the application of the Single Univalve Segment Assimilating Nucleus (SUSAN) algorithm for the reduction of coding artifacts in wavelet video-coding schemes. The SUSAN filter is as an image-structure preserving non-linear filter with low computational complexity. The filter adapts its bandwidth and stop-band attenuation based on a simple pixel classification procedure. In addition to this initial proposition, the paper provides two extensions of the original 2-D filter to the temporal domain: a two-stage 2-D+T SUSAN filter and a pure 3-D SUSAN filter. Experimental results provided in the paper provide substantial evidence of the effectiveness of the proposed approaches in terms suppression of artifacts that are typical in wavelet coding. Comparative tests show that SUSAN and its proposed extensions outperform state-of-the-art post-processing algorithms both in terms of objective (PSNR) and perceptual (PQS) quality comparisons.     

高层建筑中的风机盘管机组

概述了高层建筑空调的选择标准，描述了风机盘管机组的设计和性能。以目前风要盘管机组的设计煤地高层建筑的空调提出了建议。提出了一个使用微处理器控制器和遥控装置，且能实现加压和烟控的四和管制风机盘管系统。     

双剪高强螺栓连接研究

对用3个或4个螺栓连接的受拉节点进行26组承载力试验,节点板所用钢材等级为S690。对试验进行数值模拟,研究螺栓间的剪力分布。对文献中由高强型钢制作的类似节点进行试验,并进行数值模拟。数值结果与试验数据非常吻合,以此对规范EN1993-1-8中的承载力公式进行评价。