Minimal states and maximum free energies of materials with memory

Definitions are given of the maximum and minimum free energy associated with a given state of a material with memory. Also, the concept of a minimal state is introduced. These concepts are then explored in detail for a specific isothermal model, where the stress is given by a non-linear elastic part and a memory part which is a linear functional of the strain tensor history. It is shown that the equivalence class constituting a minimal state is a singleton except where only isolated singularities occur in the Fourier transform of the relaxation tensor derivative. If the minimal state is not a singleton, then the maximum free energy is less than the work function and is a function of the minimal state. An explicit expression is given for the maximum free energy.     

混合关系中的函数依赖及其相关规则

在实际应用中有这样一类关系数据库,其中数据项在某个属性上的取值本身又是一个关系。讨论这种混合关系中的函数依赖及其相应的相关规则具有一定的理论意义和实际应用价值。给出这种混合关系的形式定义、混合关系中4种类型的函数依赖关系以及相应的4种类型的相关规则;并给出混合关系到一般关系的转换,通过这个转换说明了混合关系与普通关系的联系及其差别。给出一个实际应用中的例子,来说明混合关系中的函数依赖和相关规则的形式多样性。     

Dual-side see-through integral imaging 3D display system based on lens array holographic optical element

We propose a dual-side see-through integral imaging 3D display based on a lens array holographic optical element (LAHOE). The display system consists of two projectors and a LAHOE. The LAHOE is fabricated according to the theory of reflective volume holograms. An interference pattern is formed by a plane-wave beam and a spherical-wave array beam, and the interference pattern is recorded into a photopolymer material. Thus, the LAHOE is formed. When a reference beam is projected into the LAHOE, the wavefront of a convex micro-lens array is reconstructed. When a phase conjugation reference beam is projected into the LAHOE, the wavefront of a concave micro-lens array is reconstructed. So, the LAHOE possesses the optical properties of a convex micro-lens array and a concave micro-lens array. The proposed display is developed using integral imaging principle and it realizes dual-side see-through integral imaging 3D display.     

Pushdown Processes: Games and Model-Checking

A pushdown game is a two player perfect information infinite game on a transition graph of a pushdown automaton. A winning condition in such a game is defined in terms of states appearing infinitely often in the play. It is shown that if there is a winning strategy in a pushdown game then there is a winning strategy realized by a pushdown automaton. An EXPTIME procedure for finding a winner in a pushdown game is presented. The procedure is then used to solve the model-checking problem for the pushdown processes and the propositional μ-calculus. The problem is shown to be DEXPTIME-complete.     

基于AHP的优化决策模型研究

对于传统的AHP求解模型,存在难以识别比较矩阵中的不一致判断的情况。通过构造两阶段线性规划模型,在第一阶段求出一致性求解范围,利用该一致性范围作为第二阶段的限制条件,借助于LINDO或者MATLAB软件求出了最优的优先权矢量,并举例说明应用这个模型的计算过程。最后,通过具体实例对模型的灵敏性进行了分析,给出了不一致性判断的识别方法。     

二进神经网络中汉明球的逻辑意义及一般判别方法

剖析二进神经元的逻辑意义对二进神经网络的规则提取是十分重要的，在布尔空间中，汉明球是一种线性可分的空间结构，如何从汉明球中提取出具有清晰逻辑意义的规则是二进神经网络研究的一个问题，通过对MofN规则表达形式的扩展，分析了汉明球的逻辑意义，提出了表达汉明球逻辑意义的LEM规则和GEM规则方法，并且讨论了汉明球和汉明补球的等价性，另一个重要的结果是证明了二进神经元和汉明球等价的充要条件，从而建立了判别汉明球的一般方法。     

Fault tolerant control for joint structure in PEMS high speed maglev train

The PEMS high speed maglev train, which features a permanent magnet inside an electromagnet, is a new kind of maglev train for long distance intercity transportation. The joint structure, which consists of two single levitation sub‐systems, is the fundamental levitation unit. Two kinds of faults are considered and corresponding fault tolerant control strategies are proposed. The first fault condition is when a gap sensor that is part of a single levitation system is faulty. For this kind of fault, a fault tolerant control strategy based on signal reconfiguration is proposed. The second fault condition is when the whole of a single levitation sub‐system is faulty. Under this condition, a faulty model is firstly established, then a fault tolerant control strategy is designed. When this kind of fault is detected, a switch from the normal controller to the fault tolerant controller can make the faulty system stable.     

REMARKS ON JOHN DISKS

Let D■R2 be a Jordan domain,D*=R2\D,the exterior of D.In this article,the authors obtained the following results:(1)If D is a John disk,then D is an outer linearly locally connected domain;(2)If D* is a John disk,then D is an inner linearly locally connected domain;(3)A homeomorphism f:R 2 →R 2 is a quasiconformal mapping if and only if f(D)is a John disk for any John disk D■R 2 ;and(4)If D is a bounded quasidisk,then D is a John disk,and there exists an unbounded quasidisk which is not a John disk.     

A type system for logic programs

A theory for a type system for logic programs is developed which addressesthe question of well-typing, type inference, and compile-time and run-time type checking. A type is a recursively enumerable set of ground atoms, which is tuple-distributive. The association of a type to a program is intended to mean that only ground atoms that are elements of the type may be derived from the program. A declarative definition of well-typed programs is formulated, based on an intuitive approach related to the fixpoint semantics of logic programs. Whether a program is well typed is undecidable in general. We define a restricted class of types, called regular types, for which type checking is decidable. Regular unary logic programs are proposed as a specification language for regular types. An algorithm for type-checking a logic program with respect to a regular type definition is described, and its complexity is analyzed. Finally, the practicality of the type system is discussed, and some examples are shown. The type system has been implemented in FCP for FCP and is incorporated in the Logix system.     

Control design based on a linear state function observer

A control design method based on a linear state function observer is proposed. The method is a semi-inverse design procedure in that the control law is not designed before the observer system, but is a result of the observer design. However, the observer design is not completely independent of the control design, but seeks to yield a feedback signal that is close to a prescribed control law. First, the observer design problem is considered as the reconstruction of a linear function of the state vector. The linear state function to be reconstructed is the given control law. Then, based on the derivation for linear state function observers, the observer design is formulated as a parameter optimization problem. The optimization objective is to generate a matrix that is close to the given feedback gain matrix. Based on that matrix, the form of the observer and a new control law can be determined. The semi-inverse design procedure can yield a reduced-order observer with dimension considerably smaller than that of the system. Two numerical examples are used to demonstrate the proposed design procedure.     

K(Knowledge)-net: building up and its dynamics

The essence of intelligence is to use certain abilities to obtain knowledge, to use that knowledge, and to operate with that knowledge. New knowledge learned by a human is often related to old existing knowledge, and sometimes we could have more conceptual knowledge based on old knowledge. So, the knowledge in the brain exists in a related structural form, and this structure is dynamic, and therefore is evolvable. Based on the understanding of the real process of learning by a human being, we discuss how to make a model to describe the dynamic structure of knowledge. This model is also a principle of artificial brain design. Most of the knowledge a child learns is from natural language and perception information, and we define this as semantic knowledge. The model to describe the process and structure of knowledge growing in a network form is called a K-net. It is a dynamic network with two main dynamics: one is new knowledge added, and the other is aggregating knowledge existing in the network with some probability. Under these very natural conditions, we found that the network is originally a simple random net, and then some characteristics of a complex network gradually appear when more new knowledge is added and aggregated. A more interesting phenomenon is the appearance of a random hierarchical structure. Does this mean emergence?     

Sensor Planning for 3D Object Search

In this paper, we provide a systematic study of the task of sensor planning for object search. The search agent's knowledge of object location is encoded as a discrete probability density which is updated whenever a sensing action occurs. Each sensing action of the agent is defined by a viewpoint, a viewing direction, a field-of-view, and the application of a recognition algorithm. The formulation casts sensor planning as an optimization problem: the goal is to maximize the probability of detecting the target with minimum cost. This problem is proved to be NP-Complete, thus a heuristic strategy is favored. To port the theoretical framework to a real working system, we propose a sensor planning strategy for a robot equipped with a camera that can pan, tilt, and zoom. In order to efficiently determine the sensing actions over time, the huge space of possible actions with fixed camera position is decomposed into a finite set of actions that must be considered. The next action is then selected from among these by comparing the likelihood of detection and the cost of each action. When detection is unlikely at the current position, the robot is moved to another position for which the probability of target detection is the highest.     

Dynamic anti-windup based control method for state constrained systems

Based on the dynamic anti-windup strategy, an alternative control methodology for state constrained systems is presented. The proposed method is an a posteriori approach for state constrained systems, which is differentiated from the usual a priori approach. That is, first a linear controller is designed to show a desirable nominal performance by ignoring state constraints. Then, an additional compensator is introduced to account for state constraints. By minimizing a reasonable performance index, a dynamic compensator is derived explicitly, which is expressed in plant and controller parameters. The proposed method not only provides a graceful performance degradation, but it also guarantees the total stability of the resulting systems. An illustrative example is given to show the effectiveness of the proposed method.     

Some results on subclass containment problems for special classes of DPDA'S related to nonsingular machines

A content-free language is said to be weakly (w-)nonsingular if it is accepted by a nonsingular deterministic pushdown automaton in the sense of Oyamaguchi, Inagaki and Honda (1980). It is undecidable whether a deterministic pushdown automaton (dpda) accepts a w-nonsingular language and whether a dpda is nonsingular in the sense of Valiant (1973). Next, the class of super-nonsingular dpda's (which is a subclass of w-nonsingular dpda's) is introduced. It is decidable whether a dpda is super-nonsingular and whether a dpda accepts a super-nonsingular language. As a consequence, the problem of deciding whether a dpda accepts an LL(k) language reduces to the problem of deciding whether a super-nonsingular dpda accepts an LL(k) language.     

Generalized theory of uncertainty (GTU)—principal concepts and ideas

Uncertainty is an attribute of information. The path-breaking work of Shannon has led to a universal acceptance of the thesis that information is statistical in nature. Concomitantly, existing theories of uncertainty are based on probability theory. The generalized theory of uncertainty (GTU) departs from existing theories in essential ways. First, the thesis that information is statistical in nature is replaced by a much more general thesis that information is a generalized constraint, with statistical uncertainty being a special, albeit important case. Equating information to a generalized constraint is the fundamental thesis of GTU. Second, bivalence is abandoned throughout GTU, and the foundation of GTU is shifted from bivalent logic to fuzzy logic. As a consequence, in GTU everything is or is allowed to be a matter of degree or, equivalently, fuzzy. Concomitantly, all variables are, or are allowed to be granular, with a granule being a clump of values drawn together by a generalized constraint. And third, one of the principal objectives of GTU is achievement of NL-capability, that is, the capability to operate on information described in natural language. NL-capability has high importance because much of human knowledge, including knowledge about probabilities, is described in natural language. NL-capability is the focus of attention in the present paper. The centerpiece of GTU is the concept of a generalized constraint. The concept of a generalized constraint is motivated by the fact that most real-world constraints are elastic rather than rigid, and have a complex structure even when simple in appearance. The paper concludes with examples of computation with uncertain information described in natural language.     

Using genetic algorithm for lot sizing and scheduling problem with arbitrary job volumes and distinct job due date considerations

This paper considers an integrated lot sizing and scheduling problem for a production–distribution environment with arbitrary job volumes and distinct due dates considerations. In the problem, jobs are firstly batch processed on a batching machine at production stage and then delivered to a pre-specified customer at the subsequent delivery stage by a capacitated vehicle. Each job is associated with a distinct due date and a distinct volume, and has to be delivered to the customer before its due date, i.e. delay is not allowed. The processing time of a batch is a constant independent of the jobs it contains. In production, a constant set-up time as well as a constant set-up cost is required before the first job of this batch is processed. In delivery, a constant delivery time as well as a constant delivery cost is needed for each round-trip delivery between the factory and the customer. Moreover, it is supposed that a job that arrives at the customer before its due date will incur a customer inventory cost. The objective is to find a coordinated lot sizing and scheduling scheme such that the total cost is minimised while guaranteeing a certain customer service level. A mixed integer formulation is proposed for this problem, and then a genetic algorithm is developed to solve it. To evaluate the performance of the proposed genetic algorithm, a lower bound on the objective value is established. Computational experiments show that the proposed genetic algorithm performs well on randomly generated problem instances.     

Stability robustness of networked control systems with respect to packet loss

This paper is concerned with stability analysis of discrete-time networked control systems over a communication channel subject to packet loss whose behavior is modeled by an i.i.d Bernoulli process with a packet dropping probability bounded by a constant. A necessary and sufficient condition for stability is obtained. A packet dropping margin is introduced as a measure of stability robustness of a system against packet dropping, and a formula for it is derived. A design method is proposed for achieving a large margin subject to a constraint that the system has a set of prescribed nominal closed-loop poles.     

Distributed self-healing control in SONET

This paper proposes a distributed self-healing architecture which contains two self-healing techniques. In this proposal, a path restoration by Self-Healing Ring (SHR) and a path restoration by Dynamic Self-Healing (DSH) algorithm are jointly applied in a network. In the architecture, SHR is applied for a part of a path which is terminated by an Add-Drop Multiplexer (ADM), and DSH is applied for another part of a path which is terminated by two Digital Cross-Connect Systems (DCSs). Based on the architecture, DSH can be applied for a part of a path which is terminated by an ADM. Next, a network design algorithm is described in order to optimize the amount of spare capacity. As a result, spare capacity reduction is realized by using the algorithm for a network where the proposed architecture is applied.     

基于通用比较模型的t-可诊断系统的特征化及并行诊断算法

文中介绍了一种系统级故障诊断模型－－通用比较模型,该模型处理器作为自身的比较器,综合经典的ＰＭＣ模型和Ｍａｅｎｇ／Ｍａｌｅｋ模型的优点,基于该报多处理器系统的ｔ＿可诊断性问题,给出了ｔ＿可诊断系统的特征化,证明了一个系统成为ｔ－可诊断系统的新的充分必要条件,其次,证明在通用比较模型中,确定故障顺集的问题等价于求解一个超图的最小横切集（Ｍｉｎｉｍｕｍ ｔｒａｖｅｒｓａｌ）,该超图是根据多处理器的通信     

Vague集的模糊逼近与模糊熵

给出了vague集转换为模糊集的一种新的方法,定义了vague集的模糊逼近。利用vague集的模糊逼近研究了vague集的模糊熵及其相关性质。