TIC: A timed calculus

TIC is a timed algebraic calculus which combines ideas from asynchronous and synchronous calculi. Time is introduced by assigning explicit time restrictions to the events of an asynchronous calculus. The semantics is defined in an operational way. Interleaving of behaviours is defined in such a way that a proper merge of events in time is achieved. Weak timed bisimulation is also defined. Examples are presented to show the applicability of the calculus to the study of timed behaviours.This work was partially supported by CICYT under the TIC program (MEDAS project)     

数字式液压逻辑流量阀的设计

数字工流量阀采用数字控制方式，调节系统流量以达到液压系统调整目的，它本身具有控制响应快、精度高、稳定性好、适应范围大等优点，在行走机械上将会得到广泛地应用。     

可编程控制器在捆扎机自动控制中的应用

介绍了一种用可编程控制器（PLC）实现捆扎机自动控制的设计方案，详细地介绍了设计过程，给出了完整的程序流程图和部分控制程序。     

Parallel branch-and-bound search in Parlog

The concurrent logic languages, of which Parlog is one, have been promoted as a new generation of software languages specifically designed for parallel programming. This paper investigates their application to a search problem commonly used as an illustration of artificial intelligence techniques, the 8-puzzle. It notes that programs written in the concurrent logic languages which do not pay attention to the parallelism can fall into two possible traps: either there is little real parallelism in them due to data dependencies, or there is too much parallelism and any practical architecture will be overwhelmed. A solution which controls the parallelism using user-defined priorities is proposed. This solution has the advantage of being architecture-independent.     

The hierarchies of knowledge and the mathematics of discovery

Rather than attempting to characterize a relation of confirmation between evidence and theory, epistemology might better consider which methods of forming conjectures from evidence, or of altering beliefs in the light of evidence, are most reliable for getting to the truth. A logical framework for such a study was constructed in the early 1960s by E. Mark Gold and Hilary Putnam. This essay describes some of the results that have been obtained in that framework and their significance for philosophy of science, artificial intelligence, and for normative epistemology when truth is relative.I am indebted to Kevin Kelly for several years of happy conversation from which the perspective and views of this paper grew, for comments on a draft of the paper, and for constructing some of the illustrations. A fellowship from the John Simon Guggenheim Memorial Foundation provided the liberty to write this paper. It was first presented in the Turing Colloquium, 1990.     

Integrating integer programming and probabilistic deduction graphs for probabilistic reasoning

Optimal solutions of several variants of the probabilistic reasoning problem were found by a new technique that integrates integer programming and probabilistic deduction graphs (PDG). PDGs are extended from deduction graphs of the and-type via normal deduction graphs. The foregoing variants to be solved can involve multiple hypotheses and multiple evidences where the former is given and the latter is unknown and being found or vice versa. The relationship among these hypotheses and evidences with possible intermediaries is represented by a causal graph. The proposed method can handle a large causal graph of any type and find an optimal solution by invoking a linear integer programming package. In addition, formulating the reasoning problem to fit integer programming takes a polynomial time. H.-L. Li was visiting the Department of Computer Sciences, University of North Texas in 1988–1989. He is with the Institute of Information Management, National Chiao Tung University, Hsinchu, Taiwan, R.O.C.     

Electrical characterization of waterside corrosion films formed on ZrNb(1%)O(0.13%)

Oxide films formed by water oxidation at 360°C on ZrNb(1%)O(0.13%) for several durations (50-300 days) were studied by impedance spectroscopy (IS) in gaseous atmosphere. The electrical behavior of oxide layers was investigated as a function of the temperature (25-300°C) at constant oxygen partial pressure (0.3 Pa). Cole-Cole diagrams suggest a frequency-temperature equivalence. A simple electrical model has been derived from the as-deduced 14 decade master curve. Equivalent circuit includes a series association of two layers exhibiting different dielectric properties: a dense layer near the oxide-metal interface and a porous layer at the waterside. Electronic conductivity is predominant within the whole temperature range, but ionic contribution was proposed to increase for temperature higher than 170°C. During the parabolic oxidation step, the oxide thickness of the barrier layer increases but oxide growth would not be only a geometrical one. The kinetic modification to a constant oxidation rate was observed to be correlated to the increase of the dense layer thickness. Such a behavior suggests that the mechanism controlling oxidation rate is not a pure mechanism of oxygen diffusion through this layer. Finally, a qualitative model of activated electrons transport based on an hopping mechanism was proposed in order to take into account that the Arrhenius diagrams of both total conductivity and dispersion factor are characterized by a break point with two activation energy values.     

XML schema, tree logic and sheaves automata

XML documents may be roughly described as unranked, ordered trees and it is therefore natural to use tree automata to process or validate them. This idea has already been successfully applied in the context of Document Type Definition (DTD), the simplest standard for defining document validity, but additional work is needed to take into account XML Schema, a more advanced standard, for which regular tree automata are not satisfactory. In this paper, we introduce Sheaves Logic (SL), a new tree logic that extends the syntax of the – recursion-free fragment of – W3C XML Schema Definition Language (WXS). Then, we define a new class of automata for unranked trees that provides decision procedures for the basic questions about SL: model-checking; satisfiability; entailment. The same class of automata is also used to answer basic questions about WXS, including recursive schemas: decidability of type-checking documents; testing the emptiness of schemas; testing that a schema subsumes another one.This work was partially supported by the French government research grant ACI TRALALA and by IST Global Computing Profundis.     

On a responsive replenishment system: a fuzzy logic approach

In today's competitive business environment, it is important that customers are able to obtain their preferred items in the shops they visit, particularly for convenience store chains such as 7–Eleven where popular items are expected to be readily available on the shelves of the stores for buyers. To minimize the cost of running such store chains, it is essential that stocks be kept to a minimum and at the same time large varieties of popular items are available for customers. In this respect, the replenishment system needs to be able to cope with the taxing demands of minimal inventory but at the same time keeping large varieties of needed items. This paper proposes a replenishment system which is able to respond to the fluctuating demands of customers and provide a timely supply of needed items in a cost–effective way. The proposed system embraces the principle of fuzzy logic which is able to deal with uncertainties by virtue of its fuzzy rules reasoning mechanism, thereby leveraging the responsiveness of the entire replenishment system for the chain stores. To validate the feasibility of the approach, a case study has been conducted in an emulated environment with promising results.