Modeling the reliability of a group membership protocol for dual-scheduled time division multiple access networks

We present reliability models for a group membership protocol designed for TDMA networks such as FlexRay, a protocol that is likely to become the de facto standard for next generation automotive networks. The models are based on discrete-time Markov chains and consider a comprehensive set of fault scenarios. Furthermore, they are parametric allowing for a sensitivity analysis. The results, obtained by a numeric solution of the models using the PRISM model-checker, show that they are computationally practical for realistic configurations and that the GMP can achieve reliability levels in the range required for safety critical applications.     

传统建筑的再探索——田子坊私宅

正如恩在本次案例中,将一个位于上海田子坊地区的老式弄堂建筑改造成了充分满足现代化生活需要的新式公寓,同时又保留了老建筑本身独特的空间划分方式,从而在设计中真正做到了对传统的扬弃。上海的弄堂保存着老上海的记忆和荣光,但随着城市的发展,这些神奇的建筑却开始逐渐离开人们的视野,被更为现代化的高密度建筑所取代。这次,设计师受托对一个弄堂建筑进行改建,而这座可怜的建筑当     

Target tracking of autonomous robotic vehicles using range‐only measurements: a switched logic‐based control strategy

This paper considers the pursuing or target tracking problem where an autonomous robotic vehicle is required to move towards a maneuvering target using range‐only measurements. We propose a switched logic‐based control strategy to solve the pursuing problem that can be described as comprising a continuous cycle of two distinct phases: (1) the determination of the bearing, and (2) the steering control of the vehicle to follow the direction computed in the previous step while the range is decreasing. We provide guaranteed conditions under which the switched closed‐loop system achieves convergence of the relative distance error to a small neighborhood around zero. Simulation results are presented and discussed.Copyright © 2011 John Wiley & Sons, Ltd.     

Performance of the most common non‐cryptographic hash functions

Non‐cryptographic hash functions (NCHFs) have an immense number of applications, ranging from compilers and databases to videogames and computer networks. Some of the most important NCHF have been used by major corporations in commercial products. This practical success demonstrates the ability of hashing systems to provide extremely efficient searches over unsorted sets. However, very little research has been devoted to the experimental evaluation of these functions. Therefore, we evaluated the most widely used NCHF using four criteria as follows: collision resistance, distribution of outputs, avalanche effect, and speed. We identified their strengths and weaknesses and found significant flaws in some cases. We also discuss our conclusions regarding general hashing considerations such as selection of the compression map. Our results should assist practitioners and engineers in making more informed choices regarding which function to use for a particular problem. Copyright © 2013 John Wiley & Sons, Ltd.     

Specific features of the electrochemical processes in the bath of an ore-smelting furnace

The mechanism of electrolysis in an ore-smelting cell modeling a bath with a conducting solid material in the melt is considered. An analysis suggests that a number of technological parameters of an ore-smelting furnace can be indirectly controlled by a change in the constant component of the phase voltage and the volt-ampere characteristic of the interelectrode gap.     

Analyzing the effects of technological,organizational and competition factors on Web knowledge exchange in SMEs

Internet technologies are increasingly being used within all knowledge management processes, including knowledge acquisition, knowledge exchange and knowledge use. Although technological issues are key drivers for Internet technologies adoption and use, organizational and environmental aspects have been found to be equally important. This paper extends previous studies on the use of Internet technologies and knowledge management by analyzing factors affecting Web knowledge exchange in small and medium-sized enterprises (SMEs). More specifically, by drawing on the technology–organization–environment framework, a model to examine how distinct contextual factors influence Web knowledge exchange in SMEs is developed. The hypotheses are tested by using structural equation modelling on a large sample of Spanish SMEs from different industries. Results suggest that IT expertise and commitment-based human resource practices positively affect Web knowledge exchange, with the latter being the strongest factor in our proposed model. In contrast, a negative relationship is found between competition and Web knowledge exchange.     

浅谈西班牙中型城市绿色基础设施战略如何为公众健康带来福祉：拉科鲁尼亚案例分析

绿色基础设施建设是一个强大的多尺度规划战略,它在全球范围内正以迅猛之势蓬勃发展,并形成了一个能够带来多种利益的复杂系统（法布士,1995;兹欧拉斯,2007,等）,包括公众的健康与福利。证据表明,它能提高生活质量,改善心理健康问题,增加幸福感。在这一战略中,绿色基础设施的选址、大小、质量以及可达性对于公众健康的改善有至关重要的作用。西班牙的拉科鲁尼亚市是一个高密度中型城市,这一案例值得人们关注。关于该市现状及新总体规划的研究阐明了应该如何通过运用景观生态原则来改善绿色规划、增加其带来的尤其是关于公众健康的利益。以SWOT研究为基础,本文将对该案例的不足进行解释说明,并思考其在绿色基础设施战略、实施过程以及设计方案中的影响。目前,已有众多研究突出了在类似于拉科鲁尼亚市的密集城市中整合与实施这些规划战略的必要性,因为它们能够改善公众健康,生活质量与景观,并作为一个有竞争力的全球优势发挥作用。本研究将阐述区域性规划在增强城市网络（西班牙北部）的空间连续性,继而将其开放至大西洋方面的必要性。