表层嵌贴预应力CFRP板条加固钢筋混凝土梁的应力传递行为

表层嵌贴预应力FRP板条加固钢筋混凝土结构技术可充分发挥FRP材料强度,且不需设置永久锚具,具有较大的潜力。以试验得到的嵌贴FRP混凝土粘结滑移关系为基础,建立了嵌贴预应力CFRP板条与混凝土的粘结应力微分方程,并根据边界条件推导了方程的解析解,得到了嵌贴预应力CFRP板条放张后界面粘结应力、CFRP拉伸应力的分析模型。与试验结果的比较表明,该模型得出的界面粘结应力及CFRP拉伸应力与试验结果吻合较好。在此基础上,考虑放张后CFRP混凝土界面不出现剥离的条件,分析了粘结界面能抵抗的最大容许预应力。     

Economic design of autoregressive moving average control chart using genetic algorithms

When designing control charts, it is usually assumed that the observations from the process at different time points are independent. However, this assumption may not be true for some production processes, e.g., the continuous chemical processes. The presence of autocorrelation in the process data can result in significant effect on the statistical performance of control charts. Jiang, Tsui, and Woodall (2000) developed a control chart, called the autoregressive moving average (ARMA) control chart, which has been shown suitable for monitoring a series of autocorrelated data. In the present paper, we develop the economic design of ARMA control chart to determine the optimal values of the test and chart parameters of the chart such that the expected total cost per hour is minimized. An illustrative example is provided and the genetic algorithm is applied to obtain the optimal solution of the economic design. A sensitivity analysis shows that the expected total cost associated with the control chart operation is positively affected by the occurrence frequency of the assignable cause, the time required to discover the assignable cause or to correct the process, and the quality cost per hour while producing in control or out of control, and is negatively influenced by the shift magnitude in process mean.     

Study of the digital divide evaluation model for government agencies–a Taiwanese local government’s perspective

Many countries have devoted increasing attention to information infrastructures. However, a gap in digitalization exists among different government agencies, causing unequal opportunities for accessing infrastructures, information, and communication technologies. This paper, based on Gowin’s Vee structure, is an empirical study of the digital divide in the context of local governments in Taiwan. A model for identifying and measuring aforementioned digital divide is constructed in this paper. We first refer to the grounded theory to draft a framework for measuring the digital divide in local governments. Then, through the use of a questionnaire distributed to experts implemented alongside the analytic hierarchy process (AHP), we generate five dimensions (including ICT infrastructure, human resources, external environment, internals of organization, and information) and 42 measures. Finally, we measure the actual levels of the digital divide in local governments with the resulting digital divide evaluation model. This paper aims to generate results that can serve as a reference for government agencies (at all levels) in the formulation of their digitalization strategies. Moreover, the digital divide evaluation model constructed in this study goes beyond existing measures and may serve as a reference for academics in the examination of methods to narrow the digital divide in various levels of governmental bodies. Taken together, the features of integration, comprehensiveness, and wide applicability of this proposed model can be considered the theoretical contributions to digital divide and local government hierarchy research.     

A probabilistic theory of the strength of short-fibre composites with variable fibre length and orientation

This paper adopts a probabilistic approach to examine the effects of fibre length and orientation distribution on the strength of short fibre composites. A general theory has been formulated in terms of fibre length and orientation distribution function as well as the composite geometrical and physical properties. The final result is presented in the form of a modified rule of mixtures. The result has been applied to discuss several special cases of fibre arrangements. They are (a) unidirectional short fibre composites with uniform fibre length, (b) unidirectional short fibre composites with fibre length distribution, (c) random short fibre composites with uniform fibre length and (d) partially-aligned short fibre composites with uniform fibre length. Comparisons of the present results with previous work are also discussed.On leave from the Institute of Space and Aeronautical Science, University of Tokyo, Japan.     

A pseudo-random number assignment strategy for the estimation of quadratic metamodels

Whereas an optimal Pseudo-Random Number (PRN) assignment strategy for simulation experiments involving the estimation of linear metamodels currently exists, no such optimal assignment strategy for quadratic metamodels has been proposed. This situation is now rectified by the introduction of a PRN assignment strategy for a quadratic metamodel for 3^k factorial designs. In addition to extending the theory from linear to quadratic metamodels, the proposed PRN strategy is shown to be superior to a number of existing and competing strategies in terms of various variance measures.     

Efficient adaptive error concealment technique for video decoding system

This paper presents a novel error concealment method for video decoding system. The proposed algorithm adaptively combines the spatial interpolation and the temporal prediction technique based on block variance and interframe correlation, to recover the lost data. The adaptive function depends on the scene change detection, motion distance and spatial information from the nearby blocks of the previous and current frames to determine the weighting of the spatial interpolation and the temporal compensation. Simulations demonstrate that the proposed technique can achieve well subjective and quantitative results, and outperforms all the others against which are compared. Even if the scene changes in the videos, this algorithm also can efficiently recover the damaged blocks for Intra(I), Predictive(P), and Bidirectional (B) frames.     

粉末注射成形溶剂脱脂研究进展

简述了粉末注射成形溶剂脱脂的基本过程,介绍了目前使用的一些溶剂脱脂方法及其研究进展,讨论了粉末注射成形溶剂脱脂工艺的发展趋势.     

Development of a molecular imprinting thick film electrochemical sensor for cholesterol detection

A combined molecular imprinting and thick film electrochemical sensor for cholesterol concentration detection had been developed. The ferro-ferric cyanide coupled redox reaction was used as the means to quantify the cholesterol presented in the test medium. This electrochemical sensor employed a modified gold working electrode, a platinum counter electrode and an Ag/AgCl reference electrode. The alkanethiol was used to form the self-assembled monolayer (SAM) on the gold working electrode. The SAM was then used with the cholesterol as the template forming the molecular imprinting layer. This sensor prototype could detect cholesterol concentrations between 66 and 700 nM and only a 1 μL of the sample volume was required.     

A Statistical Model for Simulating the Effect of LTPS TFT Device Variation for SOP Applications

In this paper, the variation characteristics of low-temperature polycrystalline silicon (LTPS) thin-film transistors (TFTs) are investigated with a statistical approach. A special layout is proposed to investigate the device variation with respect to various devices distances. Two non-Gaussian equations are proposed to fit the device parameter distributions, whose the coefficients of determination (R²) are both near 0.9, reflecting the validity of the model. Two benchmark circuits are used to compare the difference between the proposed model and the conventional Gaussian distribution for the device parameter distribution. The output behaviors of the digital and analog circuits show that the variation in the short range would greatly affect the performance of the analog circuits and would instead be averaged in the digital circuits.     

New Family of Ruthenium‐Dye‐ Sensitized Nanocrystalline TiO2 Solar Cells with a High Solar‐Energy‐Conversion Efficiency

A new type of ruthenium complexes 6 – 8 with tridentate bipyridine–pyrazolate ancillary ligands has been synthesized in an attempt to elongate the π‐conjugated system as well as to increase the optical extinction coefficient, possible dye uptake on TiO₂, and photostability. Structural characterization, photophysical studies, and corresponding theoretical approaches have been made to ensure their fundamental basis. As for dye‐sensitized solar cell applications, it was found that 6 – 8 possess a larger dye uptake of 2.4 × 10^–7 mol cm^–2, 1.5 × 10^–7 mol cm^–2, and 1.3 × 10^–7 mol cm^–2, respectively, on TiO₂ than that of the commercial N3 dye (1.1 × 10^–7 mol cm^–2). Compound 8 works as a highly efficient photosensitizer for the dye‐sensitized nanocrystalline TiO₂ solar cell, producing a 5.65 % solar‐light‐to‐electricity conversion efficiency (compare with 6.01 % for N3 in this study), a short‐circuit current density of 15.6 mA cm^–2, an open‐circuit photovoltage of 0.64 V, and a fill factor of 0.57 under standard AM 1.5 irradiation (100 mW cm^–2). These, in combination with its superior thermal and light‐soaking stability, lead to the conclusion that the concomitant tridentate binding properties offered by the bipyridine‐pyrazolate ligand render a more stable complexation, such that extended life spans of DSSCs may be expected.