• Volume 1,Issue 1,2007 Table of Contents
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    • Editorial

      2007, 1(1):1-2.

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      Abstract:

    • Some Results on Matchgates and Holographic Algorithms

      2007, 1(1):3-36.

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      Abstract:We establish a 1-1 correspondence between Valiant's character theory of match-gate/matchcircuit [13] and his signature theory of planarmatchgate/matchgrid [15], thus unifying the two theories in expressibility. In [3], we established a complete characterization of general matchgates, in terms of a set of useful Grassmann-Plucker identities. The 1-1 correspondence established in this paper gives a corresponding set of identities which completely characterizes planar-matchgates and their signatures. Applying this characterization we prove some negative results for holographic algorithms. On the positive side, we also give a polynomial time algorithm for a simultaneous node-edge deletion problem, using holographic algorithms. Finally we give characterizations of symmetric signatures realizable in the Hadamard basis.

    • Desiderata for Languages to be Used in the Defnition of Reference Business Processes

      2007, 1(1):37-65.

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      Abstract:In many modern enterprises, explicit business process de nitions facilitate the pursuit of business goals in such ways as best practice reuse, process analysis, processe ciency improvement, and automation. Most real-world business processes are large and complex. Successfully capturing, analysing, and automating these processes requires process de nition languages that capture a variety of process aspects with a wealth of details. Mostcurrent process modelling languages, such as Business Process Modelling Notation (BPMN),focus on structural control ows among activities while providing inadequate support for other process de nition needs. In this paper, we rst illustrate these inadequacies through our experiences with a collection of real-world reference business processes from the Aus-tralian lending industry. We observe that the most signi cant inadequacies include lack of resource management, exception handling, process variation, and data ow integration.These identi ed shortcomings led us to consider the Little-JIL language as a vehicle forde ning business processes. Little-JIL addresses the afore-mentioned inadequacies with a number of innovative features. Our investigation concludes that these innovative features are e ective in addressing a number of key reference business process de nition needs.

    • Entropy-Inspired Competitive Clustering Algorithms

      2007, 1(1):67-84.

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      Abstract:In this paper, the well-known competitive clustering algorithm (CA) is revisited and reformulated from a point of view of entropy minimization. That is, the second term of the objective function in CA can be seen as quadratic or second-order entropy. Along this novel explanation, two generalized competitive clustering algorithms inspired by Renyi entropy and Shannon entropy, i.e. RECA and SECA, are respectively proposed in this paper.Simulation results show that CA requires a large number of initial clusters to obtain the right number of clusters, while RECA and SECA require small and moderate number of initial clusters respectively. Also the iteration steps in RECA and SECA are less than that of CA.Further CA and RECA are generalized to CA-p and RECA-p by using the p-order entropy and Renyi's p-order entropy in CA and RECA respectively. Simulation results show that the value of phas a great impact on the performance of CA-p, whereas it has little in uence on that of RECA-p.

    • A Modal Characterization of λ-Bisimilarity

      2007, 1(1):85-99.

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      Abstract:In order to describe approximate equivalence among processes, a notion of λ-bisimilarity has been introduced in the field of process algebra. In this paper, we provide a modal characterization of λ- bisimilarity without the assumption that the metric is an ultra-metric or λ = 0, which is a generalization of one obtained by [M. Ying, Theoret. Comput.Sci., Vol. 275, 1{68].

    • Coordinated Recovery of Middleware Services:A Framework and Experiments

      2007, 1(1):101-128.

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      Abstract:Being the most popular runtime infrastructure for distributed systems, middleware can be viewed as a collection of common services. Since the development, deployment and maintenance of distributed systems rely largely on middleware services, the failure of middleware services puts a significant impact on the reliability and availability of the whole system. Though recovery-based fault tolerance is an effective way to improve the reliability of middleware services, it is far away from practice mainly because of the high complexity and cost of the recovery of correlated failures between interdependent services. In this paper,a framework for detecting and recovering the correlated failures of middleware services in an automated way is presented. First, the problem is investigated from two perspectives, i.e.,analyzing the role and impact of middleware services and illustrating a set of correlated failures in J2EE standard services as motivating examples. Then, a general coordinated recovery model is constructed with the elements necessary and su±cient for detecting and recovering correlated failures in middleware services. The supporting framework is demonstrated on three J2EE application servers, i.e., PKUAS, JBoss and JOnAS, one by one without fundamental modifications. Finally, based on the three enhanced application servers, many cases on J2EE common services, including the transaction service, database service, naming and directory service, security service and messaging service, are studied. The experiment results show the effectiveness and applicability of the framework presented in this paper.

    • An Institutional View on Categorical Logic

      2007, 1(1):129-152.

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      Abstract:We introduce a generic notion of categorical propositional logic and provide a construction of a preorder-enriched institution out of such a logic, following the Curry-Howard-Tait paradigm. The logics are speci ed as theories of a meta-logic within the logical framework LF such that institution comorphisms are obtained from theory morphisms of the meta-logic. We prove several logic-independent results including soundness and completeness theorems and instantiate our framework with a number of examples: classical, intuitionistic,linear and modal propositional logic.