热采数值模拟的快速自适应组合网格方法

本文用快速自适应组合网格方法(FAC)和逐次收据方法分别计算了一个三维、三相、二组分的热采数值模拟.计算结果表明,FAC方法和逐次收缩方法的结果接近全局加密网格上的结果(其中FAC的结果更为理想),而CPU时间仅分别为后者的22.35%和10.8%.     

Analysis of shear walls using higher order finite elements

Shear walls can be simply and conveniently modelled by using higher order plane tress finite elements which have a higher degree of variation in the displacement (and consequently the stress) function. The derivation and generation of the stiffness matrices by a computer subroutine for a series of higher order plane stress rectangular elements with any number of nodes is explained in detail and the elements are applied in the idealization of different types of shear walls in which the spandrel beams and openings are treated as a continuum. Three examples of shear wall problems are analysed to illustrate the simplicity, versatility and accuracy of this method as compared with the results of other available methods.     

铁酸锌纳米晶体的制备及表面光伏特性研究

采用偶合的共沉淀法和水热法相结合的方法,制备出ZnFe2O4纳米晶体,并利用DRS、XRD、FTIR、TEM等技术对其结构和谱学特性进行了研究,并在其基础上利用表面光电压谱(SPS)深入探讨了所制样品的表面光伏特性,研究表明样品具有较窄的禁带宽度,晶型为正尖晶石型结构,大小均匀(7nm),无团聚,表面光伏特性研究显示ZnFe2O4纳米晶体具有明显的表面和量子限域效应,有一定的捕获电子能力,在外加电场下光伏响应变化明显,在正电场下有一个最佳响应值,而当负电场达到一定值时,外电场的光伏响应将占据主导地位.     

聚砜分散胆甾型液晶研究

采用溶剂共溶法，将合成的两类胆甾型液晶分别以不同比例与合成的聚砜相混，并用差示扫描量热法和温控式偏振光显微技术测试该材料的液晶特性．结果表明，这类液晶共混材料属典型的聚合物分散液晶体系．     

An in-depth investigation into the relationships between structural metrics and unit testability in object-oriented systems

There is a common belief that structural properties of classes are important factors to determine their unit testability.However,few empirical studies have been conducted to examine the actual impact of structural properties of classes.In this paper,we employ multiple linear regression(MLR) and partial least square regression(PLSR) to investigate the relationships between the metrics measuring structural properties and unit testability of a class.The investigated structural metrics cover five property dimensions,including size,cohesion,coupling,inheritance,and complexity.Our results from open-source software systems show that:(1) most structural metrics are statistically related to unit testability in an expected direction,among which size,complexity,and coupling metrics are the most important predictors;that(2) multivariate regression models based on structural metrics cannot accurately predict unit testability of classes,although they are better able to rank unit testability of classes;that(3) the transition from MLR to PLSR could significantly improve the ability to rank unit testability of classes but cannot improve the ability to predict the unit testing effort of classes.     

基于主动支持向量机的乳腺癌微钙化簇检测

乳腺微钙化簇是早期乳腺癌的重要征象,计算机辅助的微钙化簇检测是医学影像领域的难题。为了提高检测系统的准确率,往往需要大量病灶标记,除了搜集样本本身的难度外,还需花费专家的大量时间。目前的研究工作很少涉及这个问题的解决方法。首次将基于主动学习的支持向量机技术应用到该领域,针对钙化簇感兴趣区域的特点,提出了选择训练集合的样本应该满足的基本条件。标准数据库上的实验证明,提出的方法能够大量地减轻样本标记的工作,并使乳腺癌微钙化簇检测系统的分类性能基本不变。     

A generalized model of fuzzy rough sets

The consideration of approximation problem of fuzzy sets in fuzzy information systems results in theory of fuzzy rough sets. This paper focuses on models of generalized fuzzy rough sets, a generalized model of fuzzy rough sets based on general fuzzy relations are studied, properties and algebraic characterization of the model are revealed, and relationships between this model and related models are also discussed.     

802. 11网络中一种自适应的基于预测的平滑切换算法

针对802.11网络中的平滑切换算法无法适应动态变化的网络环境的缺陷,提出了一种自适应的基于预测的平滑切换算法(adaptive predictive-based smooth handoff,APBSH).其核心思想是依据当前网络环境的变化预测下一时刻的网络环境(使用扫描紧迫性和数据传输紧迫性两个参数定量表示不同的网络环境),接着依据预测结果自适应调整扫描子阶段和数据传输子阶段的时间,不但将平滑切换控制在与当前连接的接入点(AP)失去连接之前,而且提高了切换时的数据服务质量.从实验结果看出,APBSH算法较标准的802.11切换算法和平滑切换算法,更能适应动态变化的网络环境,确保切换性能的最优化.     

An approach for business process model registration based on ISO/IEC 19763-5

To facilitate business collaboration and interoperation among enterprises, it is critical to discover and reuse appropriate business processes modeled in different languages and stored in different repositories. However, the formats of business process models are very different, which makes it a challenge to fuse them in a unified way without changing their original representations and semantics. To solve this problem, this paper uses semantic interoperability technique which is able to transform heterogeneous process models into uniform registered items. Based on the general and unambiguous metamodel for process model registration (PMR for short) in ISO/IEC 19763-5 that we proposed before, in this article, we provide a generic process model registration framework for registering heterogeneous business process models to facilitate semantic discovery of business processes across enterprises, and promote process interoperation and business collaboration. Considering that Event-driven Process Chain (EPC) is a popular process model widely used in the industry, we focus on the mapping rules and related specific transformation algorithms from EPC to PMR as an instantiation of our framework and develop an automatic process model registration tool for EPC. Moreover, we conduct a series of experiments to verify the correctness and efficiency of our proposed framework by leveraging the real data set of 604 EPCs from SAP.     

Backlight dimming based on saliency map acquired by visual attention analysis

Displays have been used in various applications from mobile phones to tablets, and the low power consumption is one of their most important factors. Backlight dimming is the most promising technique to achieve this because it significantly reduces the display power by controlling only the transmittance of liquid crystal. This paper proposes a new backlight dimming algorithm using visual attention analysis. Conventional algorithms have a serious saturation error in some images when performing backlight dimming, thereby degrading image quality. In contrast, the proposed algorithm analyzes image characteristics based on the saliency map, which considers human visual attention. It then truncates the meaningless information of the saliency map using an adaptive saliency level selection approach and calculates the maximum amount of saturation error that humans will not perceive. In addition, the proposed algorithm defines the objective function and computes the optimal starting gray level in that function to calculate the saturation error. Simulation results show that the proposed algorithm using the adaptive saliency level selection approach performs best. In addition, the average peak signal-to-noise ratio of the proposed algorithm was up to 3.762 dB higher than that of the conventional algorithm while slightly increasing the power consumption.