Syntax-driven Behavior Partitioning for Model-checking of Esterel Programs

We consider the issue of exploiting the structural form of Esterel programs to partition the algorithmic RSS (reachable state space) fix-point construction used in model-checking techniques. The basic idea sounds utterly simple, as seen on the case of sequential composition: in P; Q, first compute entirely the states reached in P, and then only carry on to Q, each time using only the relevant transition relation part. Here a brute-force symbolic breadth-first search would have mixed the exploration of P and Q instead, in case P had different behaviors of various lengths, and that would result in irregular BBD representation of temporary state spaces, a major cause of complexity in symbolic model-checking.Difficulties appear in our decomposition approach when scheduling the different transition parts in presence of parallelism and local signal exchanges. Program blocks (or “Macro-states”) put in parallel can be synchronized in various ways, due to dynamic behaviors, and considering all possibilities may lead to an excessive division complexity. The goal is here to find a satisfactory trade-off between compositional and global approaches. Concretely we use some of the features of the TiGeR BDD library, and heuristic orderings between internal signals, to have the transition relation progress through the program behaviors to get the same effect as a global RSS computation, but with much more localized transition applications. We provide concrete benchmarks showing the usefulness of the approach.     

基于检测点设置依赖图和属性表的卷回恢复算法

为了解决检测点设置过程中的Domino效应问题及卷回恢复过程中的活锁问题,并最大限度地减小时间开销,提出了基于检测点设置依赖图和属性表的卷回恢复算法。同以前的算法相比较,该算法一方面节省了用于进程之间同步的时间开销,另一方面检测点设置及卷回过程中涉及少量的相关进程。对该算法的正确性进行了证明。     

The contingent role of dependency in predicting the intention to adopt B2B e-commerce

ABSTRACT

A review of existing Electronic Commerce adoption literature reveals that the prevailing theoretical frameworks implicitly assume that organizations are independent and have complete control over their decisions to adopt innovations. Given the fact that organizations are often constrained by and depend on their environment and exchange partners to survive, this paper proposes that Resource Dependency can either be a facilitator or inhibitor of the role of Technological, Organizational, and Environmental (TOE) motivating factors. Using 239 valid responses from supply chain managers in Jordan, the study found partial support for the role of Resource Dependency as a moderator. The findings provide insights on how Resource Dependency between partners drives different patterns of innovation acceptance among potential adopters, regardless of several technological and organizational motivations to innovate. The results suggest that predicting how innovation is diffused within a market needs a detailed understanding of the inter-dependence structure among the supply chain members.     

CONTEXTUAL LANGUAGE MODELS FOR RANKING ANSWERS TO NATURAL LANGUAGE DEFINITION QUESTIONS

Question–answering systems make good use of knowledge bases (KBs, e.g., Wikipedia) for responding to definition queries. Typically, systems extract relevant facts from articles regarding the question across KBs, and then they are projected into the candidate answers. However, studies have shown that the performance of this kind of method suddenly drops, whenever KBs supply narrow coverage. This work describes a new approach to deal with this problem by constructing context models for scoring candidate answers, which are, more precisely, statistical n‐gram language models inferred from lexicalized dependency paths extracted from Wikipedia abstracts. Unlike state‐of‐the‐art approaches, context models are created by capturing the semantics of candidate answers (e.g., “novel,”“singer,”“coach,” and “city”). This work is extended by investigating the impact on context models of extra linguistic knowledge such as part‐of‐speech tagging and named‐entity recognition. Results showed the effectiveness of context models as n‐gram lexicalized dependency paths and promising context indicators for the presence of definitions in natural language texts.     

Updating method for the computation of orbits in parallel and sequential dynamical systems

In this article, we provide a matrix method in order to compute orbits of parallel and sequential dynamical systems on Boolean functions. In this sense, we develop algorithms for systems defined over directed (and undirected) graphs when the evolution operator is a general minterm or maxterm and, likewise, when it is constituted by independent local Boolean functions, so providing a new tool for the study of orbits of these dynamical systems.     

Quality aspects for component‐based systems: A metrics based approach

In component‐based development, software systems are built by assembling components already developed and prepared for integration. To estimate the quality of components, complexity, reusability, dependability, and maintainability are the key aspects. The quality of an individual component influences the quality of the overall system. Therefore, there is a strong need to select the best quality component, both from functional and nonfunctional aspects. The present paper produces a critical analysis of metrics for various quality aspects for components and component‐based systems. These aspects include four main quality factors: complexity, dependency, reusability, and maintainability. A systematic study is applied to find as much literature as possible. A total of 49 papers were found suitable after a defined search criteria. The analysis provided in this paper has a different objective as we focused on efficiency and practical ability of the proposed approach in the selected papers. The various key attributes from these two are defined. Each paper is evaluated based on the various key parameters viz. metrics definition, implementation technique, validation, usability, data source, comparative analysis, practicability, and extendibility. The paper critically examines various quality aspects and their metrics for component‐based systems. In some papers, authors have also compared the results with other techniques. For characteristics like complexity and dependency, most of the proposed metrics are analytical. Soft computing and evolutionary approaches are either not being used or much less explored so far for these aspects, which may be the future concern for the researchers. In addition, hybrid approaches like neuro‐fuzzy, neuro‐genetic, etc., may also be examined for evaluation of these aspects. However, to conclude that one particular technique is better than others may not be appropriate. It may be true for one characteristic by considering different set of inputs and dataset but may not be true for the same with different inputs. The intension in the proposed work is to give a score for each metric proposed by the researchers based on the selected parameters, but certainly not to criticize any research contribution by authors. Copyright © 2012 John Wiley & Sons, Ltd.     

语法依存性与语言习得中的非语法程序安排

语法的基本特征如抽象性、生成性、层次性等是从学术研究的角度归纳出来的．并未真正触及语法的本质属性,即语法实质：语法是人们所使用的语言的表达习惯。语法依存性作为语法的一个本质特点也长期为人们所忽略,它指的是语法在人类大脑里的内化,对语言现实的不可剥离性。而正因为对语法实质及语法依存性的认知不足,使得语言学习者的学习策略和学习重心产生偏误,违背了最初的学习目的。母语习得过程中的非语法程序安排对语言习得理论及其实践应该有更多的指导作用。     

介词结构语序研究回顾与展望

介词结构语序在现代汉语中违背了中心语边缘原则,对普遍语法理论提出了挑战,自《马氏文通》以来一直是学者研究的热点。现代汉语缺少形态标记,语序问题常常又与句法关系联在一起,因此本文首先回顾介词结构的句法功能探讨,然后综述介词结构语序特点的历时和共时研究,同时梳理介词结构语序研究的理论维度。文章最后指出,介词结构语序研究在理论视角、系统性以及对语序变异原因的深入挖掘等方面还存在不足。     

Integrating Standard Dependency Schemes in QCSP Solvers

Quantified constraint satisfaction problems (QCSPs) are an extension to constraint satisfaction problems (CSPs) with both universal quantifiers and existential quantifiers.In this paper we apply variab...     

容错的网络声明式程序

介绍了基于递归规则的网络声明式语言Netlog的语法和分布式不动点语义,定义了强良好的程序,并证明了强良好的程序的计算结果对有限的消息丢失不敏感.