Optimization of management strategies applied to the national reinforced concrete bridge stock in France

The increasing age of national highway bridge stocks demands novel management policies that can maintain or increase safety levels in the light of reducing and budgets from the government. The French Highways Agency uses its Image Qualité Ouvrages d'Art – Structural Quality Imaging (IQOA) inspection programme to determine the conditions of its bridges. The present paper principally describes the development of a model to predict different trends in bridge condition rating in the light of different management strategies. Whilst the approach described is intended to be a general method for managing bridges, it will be demonstrated by particular reference to the stock of reinforced concrete bridges managed by the French Highways Agency. The prediction model utilises Markov chains, which were chosen because they allow a non-parametric discrete model to be built, to evaluate the varying condition of the whole bridge stock over time. The development of the model is described in detail, together with how the hypotheses for applying the Markov chains were validated to accurately predict the transition matrices between different IQOA states. The paper then goes on to describe how the model is used to differentiate between different management strategies, and to predict how future costs can be optimised to give the most efficient management actions across the whole bridge stock under different constraints.     

An intelligent adaptive system for the optimal variable selections of R&D and quality supply chains

The cost of research & development (R&D) and quality management are always regarded as two major parts of total cost. The variable performance of R&D and quality design is an important index that will reflect the effectiveness of the cost reduction. This research has attempted to simultaneously vary all of the variables to achieve the global optimum for the optimal variable selections of R&D and quality design. Genetic algorithm (GA) can treat all of the variables for the global search. In this study, fuzzy refinement with orthogonal arrays was effective in improving the performance of the GA, and also showed the benefits of a good chromosome structure on the behavior of GA. It is also proposed the postponement design with temporal concept, to select the effective variables for the cost reduction of R&D and quality management design. The experimental results showed that tempo-postponement design will increase the flexibility and quick response for supply chain management. Hence, this approach can act as a useful guideline for researchers working on the optimization of the key variable selections for R&D and quality model design.     

A dynamics formulation of general constrained robots

The complexity of a standard compact-in-form Lagrangian dynamical expression is proportional to the fourth power of the number of degrees of freedom (DOF) of a robotic system. This fact challenges both simulation and control of robots with hyper degrees of freedom. In this paper, a systematic approach for deriving the dynamical expression of so-called general constrained robots is proposed. This proposed approach has two main features. First, it uses the subsystem dynamics such as the dynamics of joints and rigid links to construct the dynamical expression of the entire robotic system in a closed form. The complexity of the resulted dynamic expression is linearly proportional to the number of DOF of a robotic system. Second, it extends the standard dynamical form and properties of the conventional single-arm constrained robots to a class of more general robotic systems including the coordinated multiple-arm robotic systems. Three spaces, namely the general joint space, the general task space, and the extended subsystems space, are connected through corresponding velocity/force mapping matrices.An erratum to this article can be found at     

Tornado API分析及第三方工具链集成技术

分析了Tornado集成开发环境及GCC编译器.重点讨论了Tornado应用程序接口.对Tornado的定制与扩展及第三方工具链的集成技术进行了较深入的探讨.修改GCC-3.3.2部分源码后,采用新的集成策略,把它成功地集成到了Tornado开发环境中.     

中外现代物流发展的历程与比较

文章介绍了物流的起源和概念;着重叙述了中外现代物流发展所经历的不同阶段;并对中外物流发展的不同阶段作了路径比较和原因分析.     

<Emphasis Type="Italic">M/G</Emphasis>/1 System with Adjustment at the Beginning of Its Busy Period

M/G/1 queuing system is considered in which the first incoming request initializes system adjustment. After adjustment, the system services the first and then the next incoming requests. Ergodic probabilities are computed based on the theory of regenerative processes and on the busy period and time of staying in different states. Recurrence is analyzed which corresponds to the mathematical expectation of the time of staying in different states.The study was sponsored by the Hungarian National Fund for Scientific research (Grants OTKA T034110 and T034280/2000) and by the Fund of the Research Group on Number Theory of the Hungarian Academy of Sciences.__________Translated from Kibernetika i Sistemnyi Analiz, No. 1, pp. 117–123, January–February 2005.     

关于可列非齐次马氏链状态三元序组出现频率的一类强大数定律

本文通过可列非齐次马氏链在 Wiener 概率空间中的一种实现,给出了关于状态三元序组出现频率的一类强大数定律.     

α-Sulfonated fatty acid esters: I. Structural effects of sodium α-sulfonated fatty acid higher alcohol esters on surface-active properties and emulsification ability

The surface-active properties and emulsification ability of sodium α-sulfonated fatty acid esters, C_mH_2m+1CH-(SO₃Na)COOC_nH_2n+1, were studied as a function of the hydrophobic alkyl chainlength in the fatty acid (m=8−16) and the alcohol (n=8−18). As a result, it was discovered that sodium α-sulfonated fatty acid esters have a structural effect on the Krafft point different from that of amphiphiles with short alkyl chains. Moreover, some of the α-sulfonated fatty acid esters have quite low interfacial tensions, as well as non-foaming properties, which depend upon the total (m+n) number of carbon atoms in the alkyl chains.     

A complement about almost controllability subspaces

We show that, for any almost controllability subspace, there exist a maximal input chain and a family of state feedbacks which lead to the well known ‘feedback-chain’ expression for this subspace.     

Renewal type bootstrap for Markov chains

In this paper we treat a renewal type of bootstrap for atomic Markov chains under minimal moment conditions on renewal times, i.e.Er ²<∞. Three main results are: a) if a Markov chain satisfies the CLT for the mean then it also satisfies a bootstrap CLT; b) if a Markov chain satisfies a uniform CLT over classes of functions then, it also satisfies bootstrap uniform CLT with minimal condition on envelope functionF; c) we establish second order correctness for this procedure. All results are for “in probability” bootstrap and constitute the final word in this setting.