Jinzhao Wu

A discrete invasive weed optimization algorithm for solving traveling salesman problem

Abstract The Traveling Salesman Problem (TSP) is one of the typical NP-hard problems. Efficient algorithms for the TSP have been the focus on academic circles at all times. This article proposes a discrete invasive weed optimization (DIWO) to solve TSP. Firstly, weeds individuals encode positive integer, on the basis that the normal distribution of the IWO does not change, and then calculate the fitness value of the weeds individuals. Secondly, the 3-Opt local search operator is used. Finally, an improved complete 2-Opt (I2Opt) is selected as a second local search operator for solve TSP. A benchmarks problem selected from TSPLIB is used to test the algorithm, and the results show that the DIWO algorithm proposed in this article can achieve to results closed to the theoretical optimal values within a reasonable period of time, and has strong robustness.

Realizing ternary quantum switching networks without ancilla bits

This paper investigates the synthesis of quantum networks built to realize ternary switching circuits in the absence of ancilla bits. The results we established are twofold. The first shows that ternary Swap, ternary NOT and ternary Toffoli gates are universal for the realization of arbitrary n × n ternary quantum switching networks without ancilla bits. The second result proves that all n×n quantum ternary networks can be generated by NOT, Controlled-NOT, Multiply-Two and Toffoli gates. Our approach is constructive.

Action refinement for true concurrent real time

Action refinement is an essential operation in the design of concurrent systems, real-time or not. In this paper, we develop an action refinement technique in a real-time non-interleaving causality-based setting, a timed extension of bundle event structures that allows for urgent interactions to model time-out. A syntactic action refinement operation is presented in a timed process algebra based on the internationally standardised specification language LOTOS. We show: (1) that the behavior of the refined system can be inferred compositionally from the behavior of the original system; (2) from the behaviors of the processes substituted for actions with explicitly represented start-points, that the timed versions of a linear-time equivalence (pomset trace equivalence) and a branching-time equivalence (history-preserving bisimulation equivalence) are both congruences under our refinement; and (3) that the syntactic and semantic action refinements we developed coincide under these equivalence notions with respect to a metric and a CPO (complete partial order) based denotational semantics. Therefore, our refinement operations behave well. They also meet the commonly expected properties.

Towards action refinement for true concurrent real time

Abstract.Action refinement is an essential operation in the design of concurrent systems, real-time or not. In this paper we develop a theory of action refinement in a real-time non-interleaving causality based setting, a timed extension of bundle event structures that allows for urgent interactions to model timeout. The syntactic action refinement operation is presented in a timed process algebra as incorporated in the internationally standardised specification language LOTOS. We show that the behaviour of the refined system can be inferred compositionally from the behaviour of the original system and from the behaviour of the processes substituted for actions with explicitly represented start points, that the timed versions of a linear-time equivalence, termed pomset trace equivalence, and a branching-time equivalence, termed history preserving bisimulation equivalence, are both congruences under the refinement, and that the syntactic and semantic action refinements developed coincide under these equivalence relations with respect to a metric denotational semantics. Therefore, our refinement operations behave well. They meet the commonly expected properties.

Bundle event structures: a revised cpo approach

Bundle event structures equipped with a partial order ≤ have been used to give a true concurrency denotational semantics for LOTOS. This model has also been extended by time and stochastic information. Unfortunately it fails to yield a complete partial order (cpo) as we illustrate by an example.We propose a subset of all bundle event structures such that it forms a cpo. This subset is closed under the usual operators on bundle event structures. And as a consequence these operators are continuous. Therefore, this subset can be used to give a denotational semantics of LOTOS.

Action Refinement for Probabilistic Processes with True Concurrency Models

In this paper, we develop techniques of action refinement for probabilistic processes within the context of a probabilistic process algebra. A semantic counterpart is carried out in a non-interleaving causality based setting, probabilistic bundle event structures. We show that our refinement notion has the following nice properties: the behaviour of the refined system can be inferred compositionally from the behaviour of the original system and from the behaviour of the systems substituted for actions; the probabilistic extensions of pomset trace equivalence and history preserving bisimulation equivalence are both congruences under the refinement; and with respect to a cpo-based denotational semantics the syntactic and semantic refinements coincide with each other up to the aforementioned equivalence relations when the internal actions are abstracted away.

Refinement of Actions in a Real-Time Process Algebra with a True Concurrency Model

Abstract In this paper, we develop techniques of action refinement in a real-time process algebra that allows urgent interactions to model timeout. Semantic counterpart is carried out in a real-time non-interleaving causality based setting, timed bundle event structures. We show that our refinement notions have the following nice properties: the observable behaviour of the refined system can be inferred compositionally from the observable behaviour of the original system and from the observable behaviour of the processes substituted for the actions; the timed extensions of observational pomset trace equivalence and observational history preserving bisimulation equivalence are both congruences under our refinement; and the syntactic and semantic refinements coincide up to the aforementioned equivalence relations with respect to a cpo-based denotational semantics.

Adding Action Refinement to Stochastic True Concurrency Models

Action refinement is an essential operation in the hierarchical design of concurrent systems, stochastic or not. In this paper we develop techniques of action refinement in a stochastic true concurrency causality based setting, stochastic bundle event structures. A stochastic LOTOS-like process algebra is used as the specification language, where the corresponding syntactic operation of action refinement is carried out. We show that the behaviour of the refined system can be inferred compositionally from the behaviour of the original system and from the behaviour of the systems substituted for actions with explicitly represented start points, that the stochastic versions of pomset trace equivalence and history preserving bisimulation equivalence are both congruences under the refinement, and that the semantic and syntactic action refinements coincide under these equivalence relations with respect to a cpo-based denotational semantics. Therefore, our refinement operations behave well. They meet the commonly expected properties.

Application of Wu's method to symbolic model checking

Model checking is widely used in verifying properties of concurrent systems. As an improvement, symbolic model checking uses OBDDs to alleviate the state explosion problem. However, the size of OBDDs greatly increases with the system becoming larger and more complex. In symbolic computation Wus method is efficient to solve algebraic equations, and has succeeded in geometry theorem proving. In this paper, we present a framework to apply Wus method to symbolic model checking. Briefly, symbolic model checking is carried out by using Wus method to calculate the characteristic sets of polynomials that represent Kripke structures as well as CTL formulas. This is a new approach to model checking, and is a new successful application of Wus method.

On Fuzzy Rough Sets and Their Topological Structures

The core concepts of rough set theory are information systems and approximation operators of approximation spaces. Approximation operators draw close links between rough set theory and topology. This paper is devoted to the discussion of fuzzy rough sets and their topological structures. Fuzzy rough approximations are further investigated. Fuzzy relations are researched by means of topology or lower and upper sets. Topological structures of fuzzy approximation spaces are given by means of pseudoconstant fuzzy relations. Fuzzy topology satisfying (CC) axiom is investigated. The fact that there exists a one-to-one correspondence between the set of all preorder fuzzy relations and the set of all fuzzy topologies satisfying (CC) axiom is proved, the concept of fuzzy approximating spaces is introduced, and decision conditions that a fuzzy topological space is a fuzzy approximating space are obtained, which illustrates that we can research fuzzy relations or fuzzy approximation spaces by means of topology and vice versa. Moreover, fuzzy pseudoclosure operators are examined.