Stability of solutions of stochastic functional-differential equations with poisson switchings and entire prehistory

The Markov properties of the solutions of Ito-Skorokhod stochastic functional-differential equations (SFDEs) with entire prehistory are considered, the concept of a weak infinitesimal operator is introduced for a Markov process that is a solution of an SFDE, and the strong solution of the SFDE is analyzed for stability. Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 123–134, January–February 2009.     

Choosing the parameter of a modified additive-averaged splitting algorithm

The problem-solving time and the solution accuracy are expressed as functions of a parameter. An optimization problem of choosing the parameter using a “time cost–solution accuracy” criterion is considered. A Pareto-optimal set of solutions is obtained. The best value of the parameter is chosen by the ideal-point method. Translated from Kibernetika i Sistemnyi Analiz, No. 4, pp. 98–105, July–August 2009.     

A comprehensive decision making structure for partitioning of make-to-order, make-to-stock and hybrid products

Manufacturing systems produce their products by making use of three main strategies: make-to-order, make-to-stock and hybrid (combination of MTO and MTS strategies) systems. Hence, several products must be considered and partitioned in terms of many different conflicting criteria, leading to a large set of subjective or ambiguous data. Thus, an effective evaluation approach is essential to improve decision quality. In this paper a comprehensive decision, making structure is proposed to choose the proper strategy for producing the products. It consists of a novel hybrid methodology, which combines analytical hierarchy process (AHP) and technique for order performance by similarity to ideal solution (TOPSIS) for partitioning of products. In this study, the rating of each alternative regarding different criteria (throughout the TOPSIS technique) is described by means of linguistic variables. Furthermore, fuzzy AHP methodology is applied to determine the weights of evaluation criteria. At the end, the effectiveness of the proposed model is demonstrated through a case study.     

Conference key agreement protocol with non-interactive fault-tolerance over broadcast network

Most conventional conference key agreement protocols have not been concerned with a practical situation. There may exist some malicious conferees who attempt to block conference initiation for some purposes, e.g. commercial, political or military benefit. Instances where conference must be launched immediately due to emergency, efficient detection of malicious behavior would be needed. Recently, Tzeng (IEEE Trans. Comput. 51(4):373–379, 2002) proposed a fault-tolerant conference key agreement protocol to address the issue where a conference key can be established among conferees even though malicious conferees exist. However, his protocol might be complex and inefficient during fault-detection. In the case where a malicious conferee exists and a fault-tolerant mechanism is launched, complicated interactions between conferees will be required. In this paper, we introduce a novel strategy, where any malicious conferee may be identified and removed from the conferee list without any interaction. With such a non-interactive fault-tolerance, conferences could be established and started efficiently. A complete example of our protocol will be given to describe the fascinating fault-tolerance. We analyse the security of our protocol regarding four aspects, i.e. correctness, fault-tolerance, active attack and passive attack. The comparisons of performance between our protocol and that of Tzeng are also shown. As a whole, the advantage of our protocol is superior to that of Tzeng under the situation where malicious conferees exist.

明式有束腰罗汉床的曲线美

明式家具不论是在选材用料、造型设计、榫卯构成,还是在加工制作和装饰手法等方面的造诣直至今天还为人折服,人们认识到其价值的同时,也在不断的仿制明式家具的风格。文章通过具体分析明式家具中罗汉床的曲线造型这一点,使明式罗汉床的特点更明确化、具体化。希望通过分析,为现代家具设计师,特别是罗汉床的设计能提供一个清晰准确的定位。     

基于改进的基因表达式编程算法在作业车间调度问题中的应用

文章提出一种新颖的方法一改进的基因表达式编程算法来求解作业车间调度问题。作业车间调度问题是许多实际生产调度问题的简化模型,基因表达式编程算法结合了遗传算法和遗传编程的优点,具有更强的解决问题能力,对基因表达式编程算法进行改进使其在作业车间调度问题的应用上更加有效;最后应用一个实例来验证提出方法的有效性。     

基于惩罚函数的演化测试优化方法研究

演化测试是一种有效的测试用例自动生成技术。它将测试用例的生成的过程转化为一个利用遗传算法进行数值优化的问题,可以自动生成高质量的测试用例。目前,演化测试技术已经在许多测试领域被广泛地研究。研究发现,演化测试过程中无效解和局部最优解的存在扰乱了演化正常进行,降低了演化测试的性能。针对演化测试中存在的问题,提出基于惩罚函数的适应值函数F（x）,对无效解和局部最优解进行惩罚,有助于演化过程中根据适应值选择更合适的个体进行遗传操作,提高演化测试的性能。实验结果表明,F（x）有效降低了无效解和局部最优解的适应值,提高了演化测试的性能。     

Iterative control approach to high-speed force-distance curve measurement using AFM: time-dependent response of PDMS example

Force-distance curve measurements using atomic force microscope (AFM) has been widely used in a broad range of areas. However, currently force-curve measurements are hampered the its low speed of AFM. In this article, a novel inversion-based iterative control technique is proposed to dramatically increase the speed of force-curve measurements. Experimental results are presented to show that by using the proposed control technique, the speed of force-curve measurements can be increased by over 80 times--with no loss of spatial resolution--on a commercial AFM platform and with a standard cantilever. High-speed force curve measurements using this control technique are utilized to quantitatively study the time-dependent elastic modulus of poly(dimethylsiloxane) (PDMS). The force-curves employ a broad spectrum of push-in (load) rates, spanning two-order differences. The elastic modulus measured at low-speed compares well with the value obtained from dynamic mechanical analysis (DMA) test, and the value of the elastic modulus increases as the push-in rate increases, signifying that a faster external deformation rate transitions the viscoelastic response of PDMS from that of a rubbery material toward a glassy one.     

Using ROC curves to assess the efficacy of several detectors of damage-induced nonlinearities in a bolted composite structure

We offer a comparison of several different detectors of damage-induced nonlinearities in assessing the connectivity of a composite-to-metal bolted joint. Each detector compares the structure's measured vibrational response to surrogate data, conforming to a general model for the healthy structure. The strength of this approach to detection is that it works in the presence of certain types of varying ambient conditions and is valid for structures excited with any stationary process. Here we employ several such detectors using dynamic strain response data collected near the joint as the structure was driven using simulated wave forcing (taken from the Pierson–Moskowitz frequency distribution for wave height). In an effort to simulate in situ monitoring conditions the experiments were carried out in the presence of strongly varying temperatures. The performance of the detectors was assessed using receiver operating characteristic (ROC) curves, a well known method for displaying detection characteristics. The ROC curve is well suited to the problem of vibration-based structural health monitoring applications where quantifying false positive and false negative errors is essential. The results of this work indicate that using the estimated auto-bicoherence of the systems response produced the best overall detection performance when compared to features based on a nonlinear prediction scheme and another based on information theory. For roughly 10% false alarms, the bicoherence detector gives nearly 90% probability of detection (POD). Conversely, for several of the other detectors 5–10% false alarms leads to 70% POD. While the bicoherence (and bispectrum) have been used previously in the context of damage detection, this work represents the first attempt at using them in a surrogate-based detection scheme.     

Computation of medial axis and offset curves of curved boundaries in planar domain

In this paper, we begin our research from the generating theory of the medial axis. The normal equidistant mapping relationships between two boundaries and its medial axis have been proposed based on the moving Frenet frames and Cesaro’s approach of the differential geometry. Two pairs of adjoint curves have been formed and the geometrical model of the medial axis transform of the planar domains with curved boundaries has been established. The relations of position mapping, scale transform and differential invariants between the curved boundaries and the medial axis have been investigated. Based on this model, a tracing algorithm for the computation of the medial axis has been generated. In order to get the accurate medial axis and branch points, a Two_Tangent_Points_Circle algorithm and a Three_Tangent_Points_Circle algorithm have been generated, which use the results of the tracing algorithm as the initial values to make the iterative process effective. These algorithms can be used for the computation of the medial axis effectively and accurately. Based on the medial axis transform and the envelope theory, the trimmed offset curves of curved boundaries have been investigated. Several numerical examples are given at the end of the paper.