A Logical Design Method for Relational Databases Based on Generalization and Aggregation Semantics

In this paper,a series of esign methods for relational databases based on generalization and aggregation semantics is set up.The relationship between a class and its subclass s considered as a scheme constraint.The concept of inheritance dependencies,which describes the multiple inheritance among schemes, is presented in the paper.It is shown that the inference rules for inheritance dependencies are sound and complete.Furthermore,a series of results about the closure of inheritance dependencies and the minimal set of inheritance dependencies,which are analogues to functional dependencies,is obtained.In order to describe the aggregation semantices,the concept of aggregation dependencies is given.It is easy to implement these constraints under relational database management systems.     

XML弱函数依赖及其推理规则

XML函数依赖问题是进行XML数据库后续研究的基础。首先基于M.Arenas等人给定的XML中DTD和XML树的定义，提出空值、不完全树元组、数据值偏序、最小扩展树等概念，在此基础上，给出弱函数依赖及其满足性的定义；其次研究了XML弱函数依赖的逻辑蕴含问题，提出一组适合XML空值模型的函数依赖推理规则集；最后给出推理规则集的正确性和完备性证明。     

面向类集成测试序列生成的强化学习研究

集成测试是软件测试过程中不可缺少的步骤, 针对在集成测试中如何对系统中的类合理排序的问题, 国内外研究者提出了多种生成类集成测试序列的方法, 然而他们大多没有将测试桩复杂度作为评估测试代价的指标.针对该问题, 提出面向类集成测试序列生成的强化学习研究方法, 以总体测试桩复杂度为评价测试代价的指标, 生成测试代价尽可能低...     

A Novel Method for Aggregation of Bayesian Networks without Considering an Ancestral Ordering

A good method of combining Bayesian networks (BNs) should be a generic one that ensures a combined BN meets three important criteria of avoiding cycles, preserving conditional independencies, and preserving the characteristics of individual BN parameters. All combination methods assumed that there is an ancestral ordering shared by individual BNs. If this assumption is violated, then avoiding cycles may be inefficient.

In this paper, without considering an ancestral ordering, we introduce a novel method for aggregation of BNs. For this purpose, we first combine the BNs using the modification of the method introduced by Feng et al. We then use the simulated annealing algorithm for getting an acyclic graph in which the minimum arcs have been removed. Using this method, most of the conditional independencies are preserved. We compare the results of the proposed method with the two classical BNs combination methods; union and intersection, and hence to demonstrate the distinctive advantages of the proposed BNs combination method.     

An approach of class integration test order determination based on test levels

In recent years, many approaches have been developed to determine the order of tested classes in interclass integration test. However, existing approaches are inaccurate, as they ignore the influence of abstract classes and polymorphism. In this paper, we propose a test‐level‐based approach to deal with class‐integration‐test order, in which both abstract classes and polymorphism are taken into account. First, based on interclass dependence analysis, we develop an edge‐removing algorithm to eliminate cycles caused by static and dynamic dependencies, taking abstract classes and polymorphism into account. Then, after eliminating cycles, we propose a class‐integration‐test order algorithm based on test levels, including static and dynamic test levels. In this algorithm, we take into account the fact of some test levels infeasible caused by the characteristic of abstract classes that they cannot be instantiated and offer corresponding adjustment strategy. Finally, we design and implement a test level order generator. The experimental results show that the proposed strategy needs less test stubs than the most typically graph‐based approaches. Copyright © 2014 John Wiley & Sons, Ltd.     

面向对象类簇级测试中控制依赖分析方法研究

类簇控制依赖信息是进行类间数据流测试的基础。本文通过克服已有类控制流分析的不足之处,提出了CCFG算法,依照类间测试序,通过分析继承、聚集和关联等类间关系特 征进而增量式地构造类间控制流图（ICCFG算法）,并初步探讨了动态控制依赖分析方法。实验表明,上述控制流分析方法可方便地用于类间数据流测试,并能有效地探测定义一使用错误。     

A formal method for inheritance graph hierarchy construction

In [M.M. Gammoudi et al., in: Proceedings Lecture Notes of the International Conference on Conceptual Modeling ER'97, Los Angeles, November 1997; M.M. Gammoudi et al., in: The 18th International Conference on Conceptual Modelling (ER'99), Paris, November 15–18, Lecture Notes, Springer, Berlin, 1999] we proposed a semi-automatic method for generating inheritance graph hierarchy for the purpose of assisting the designer during the definition of his conceptual schema. The motivation for this work was the very few approaches which attempt to provide methods and tools for designing inheritance graph in object databases [R. Wille, in: E. Diday (Ed.), Data Analysis, Learning Symbolic and Numeric Knowledge, Nova Science, New York, 1989], and object software [A.L. Winblad et al., Object-Oriented Software, Addison-Wesley, New York, 1990]. To address some limitations found in our work, we propose a new method whose principles are: (i) From a binary relation which represents the links between entities and their properties and methods, our proposed heuristic generates and organizes incrementally a set of optimal rectangles into a brut inheritance graph (BIG). (ii) BIG is refined and submitted to the designer. (iii) The designer can modify, add or remove classes, attributes or methods in the binary relation and activate step (i) until he obtains a proper class hierarchy or an optimal inheritance graph.     

Improved method to generate path-wise test data

Gupta et al.,propsed a method ,which is referred to as the Iterative Relaxation Method ,to generate test data for a given path in a program by linearizing the predicate functions.In this paper,a model language is presented and the properties of static and dynamic data depen-dencies are investigated ,The notions in the Interative Relaxation Method are defined formally.The predicate slice proposed by Gupta et al.is extended to path-wise static slice.The correctness of the constructional algorithm is proved afterward The improvement shows that the constructions of predicate slice and input dependency set can be omitted .The equivalence of systems of constraints generated by both methods is proved ,The prototype of path-wise test data generator is presented in this paper,The experiments show shat our method is practical ,and fits the path-wise automatic generation of test data for both whicte -bos testing and black-blx testing.     

多目标依存建模在特定目标情感分类中的应用

特定目标情感分类旨在准确判别句子中目标的情感极性,现有的方法大多只对单一目标进行分析,而忽略了同一句中多个目标之间存在的依存性。为了有效建模目标之间的依存性,该文提出一种基于多目标依存建模的图卷积网络模型。首先,通过注意力机制对目标进行上下文语义编码;然后,根据句子的依存句法树构建多目标依存图,再根据多目标依存图使用图卷积网络对多个目标之间的依存性进行建模;最后,利用生成的目标表示进行情感分类。该模型在SemEval 2014 Task4 Restaurant和Laptop两个数据集上进行实验,结果表明,该文模型相比基于标准图卷积网络的模型性能有显著提高,在特定目标情感分类任务中更具竞争力。     

图依赖研究与应用综述

图依赖是用于解决图数据的数据一致性问题的数据质量规则。基于图依赖提升数据一致性的过程通常分为图依赖定义与形式化、图依赖自动挖掘、基于图依赖的数据一致性提升三步。介绍了针对数据一致性的图依赖理论,并根据拓展类型将图依赖分为基于结构约束拓展、基于语义约束拓展和基于外部约束拓展的图依赖;综述并对比了从图数据中自动挖掘图依赖及其拓展的算法;分析了应用图依赖提高数据一致性的研究现状;总结了当前研究中仍存在的问题,并依据问题展望了图依赖在数据质量领域的应用前景。     

Multi-objective genetic algorithms based automated clustering for fuzzy association rules mining

Researchers realized the importance of integrating fuzziness into association rules mining in databases with binary and quantitative attributes. However, most of the earlier algorithms proposed for fuzzy association rules mining either assume that fuzzy sets are given or employ a clustering algorithm, like CURE, to decide on fuzzy sets; for both cases the number of fuzzy sets is pre-specified. In this paper, we propose an automated method to decide on the number of fuzzy sets and for the autonomous mining of both fuzzy sets and fuzzy association rules. We achieve this by developing an automated clustering method based on multi-objective Genetic Algorithms (GA); the aim of the proposed approach is to automatically cluster values of a quantitative attribute in order to obtain large number of large itemsets in less time. We compare the proposed multi-objective GA based approach with two other approaches, namely: 1) CURE-based approach, which is known as one of the most efficient clustering algorithms; 2) Chien et al. clustering approach, which is an automatic interval partition method based on variation of density. Experimental results on 100 K transactions extracted from the adult data of USA census in year 2000 showed that the proposed automated clustering method exhibits good performance over both CURE-based approach and Chien et al.’s work in terms of runtime, number of large itemsets and number of association rules.     

资源约束下的基于类依赖关系的微服务识别方法

为有效提升基于微服务架构的遗留软件系统重构的自动化水平,根据存在依赖关系的两个类所操作的资源数据之间存在着一定相关性的原则,提出了一种资源约束下基于类依赖关系的微服务识别方法。首先,根据遗留软件程序中的类依赖关系构建类依赖关系图,并设置每个类的资源实体标签;然后,设计了基于资源实体标签的类依赖关系图划分算法,用以划分原软件系统和得到候选微服务;最后,合并依赖程度较高的候选微服务,从而得到最终的微服务集合。基于GitHub的4个开源项目的实验结果表明,所提方法具有高于90%的微服务划分准确率,证实了同时考虑不同类之间的依赖关系和资源约束对于微服务识别是合理和有效的。     

资源约束下的基于类依赖关系的微服务识别方法

为有效提升基于微服务架构的遗留软件系统重构的自动化水平，根据存在依赖关系的两个类所操作的资源数据之间存在着一定相关性的原则，提出了一种资源约束下基于类依赖关系的微服务识别方法。首先，根据遗留软件程序中的类依赖关系构建类依赖关系图，并设置每个类的资源实体标签；然后，设计了基于资源实体标签的类依赖关系图划分算法，用以划分原软件系统和得到候选微服务；最后，合并依赖程度较高的候选微服务，从而得到最终的微服务集合。基于GitHub的4个开源项目的实验结果表明，所提方法具有高于90%的微服务划分准确率，证实了同时考虑不同类之间的依赖关系和资源约束对于微服务识别是合理和有效的。     

从领域需求到产品线体系结构的映射——一种面向特征的方法

领域需求之间的依赖关系对软件产品线的体系结构有很大的影响,在已有的面向特征的管理产品线需求依赖的方法中很少有研究从需求到产品线体系结构的映射.基于一种特征依赖的分类方法,提出了从领域需求到特征,以及从特征到产品线体系结构的映射规则.通过这些映射规则,一致的需求通过映射得到一致的产品线核心资产,从而减少产品线中核心资产的不一致性并增加产品线的复用程度.用金融领域的现货交易产品线作为实例说明这个方法的实用性.     

From the Happened-Before Relation to the Causal Ordered Set Abstraction

Several works in distributed systems have been designed based on the Happened-Before Relation (HBR). Most of these works intend to be efficient in their implementation by identifying and ensuring dependency constraints among single events. Even when the minimal causal dependencies among events have been clearly identified, the evolution of systems, which may involve a high number of processes and a high volume of transmitted data, calls for the need to design even more efficient approaches. This paper proposes the Causal Ordered Set Abstraction (CAOS) where the causally related events are arranged in sets that are strictly causally ordered. As for single events, CAOS establishes that any pair of resultant sets can be, and can only be, causally or concurrently related. We claim that our ordered set abstraction can be used to design more efficient algorithms based on the HBR principle. This assertion is based on two main properties. First, CAOS attains a consistent compact representation of a distributed computation. Second, as a consequence of the causal ordering of the events in the resultant sets, it is sufficient to verify only a pair of single events, one per each set, in order to determine whether these sets are causally or concurrently related, regardless of the cardinality of the sets.     

基于不确定使用边的间接依赖过滤方法

起源过滤是通过改造起源图中的节点、边或间接依赖关系,隐藏起源图中的敏感信息,实现起源安全发布的新兴技术。针对现有起源过滤研究主要关注节点和边的过滤,较少研究间接依赖的过滤问题。扩展现有“删除+修复”的间接依赖过滤策略,提出了一种起源间接依赖过滤方法。形式地定义不确定的使用边,并阐明引入不确定的使用边修复被误断的间接依赖的基本原理;提出一种基于不确定使用边的间接依赖过滤机制,该机制先删除敏感路径中的恰当的使用边断开敏感间接依赖,再采用最小代价法引入恰当的不确定的使用边修复被误断的非敏感间接依赖。实验结果表明,与现有的间接依赖过滤机制相比,该方法可以在满足结构约束的同时保持过滤视图的溯源效用。     

INCREASING RADIUS SEARCH SCHEMES FOR THE MOST SIMILAR STRINGS ON THE BURKHARD-KELLER TREE

In this work, search schemes are proposed for the most strings similar to a given one, based on the Levenshtein directional distance (Levenshtein, 1966), working on a Burkhard-Keller structure (Burkhard and Keller, 1973; Nevalainen and Ka-tajainen, 1982), organized by the transposition-invariant distance (Santana et al., 1987), and using an increasing search radius as opposed to the decreasing search radius schemes (Santana et al., 1988). Some organization approaches are studied to find the best way to improve search performance. The test results are analyzed, comparing these approaches and the different search schemes.     

多域间动态角色转换的职责分离

两个或多个管理域间的安全互操作是一个重要的研究课题．Kapadia等人提出的IRBAC 2000模型通过动态角色转换灵活地实现了域间安全互操作．在IRBAC 2000模型中每个管理域均采用RBAC模型，职责分离是RBAC模型支持的最基本的3个安全原则之一，并可用一组静态互斥角色约束来表示．而IRBAC 2000模型没有考虑职责分离．因此，对动态角色转换违背静态互斥角色约束的各种情形进行了详细分析，并抽象出各种情形的本质特征；对动态角色转换是否会违背静态互斥角色约束提供了一种判定方法并给出了相应的算法；提出了使用先决条件来加强IRBAC 2000模型安全性的保护机制．     

Structure-sensitive semantic matching for aggregate question answering over knowledge base

Aggregate question answering essentially returns answers for given questions by obtaining query graphs with unique dependencies between values and corresponding objects. Word order dependency, as the key to uniquely identify dependency of the query graph, reflects the dependencies between the words in the question. However, due to the semantic gap caused by the expression difference between questions encoded with word vectors and query graphs represented with logical formal elements, it is not trivial to match the correct query graph for the question. Most existing approaches design more expressive query graphs for complex questions and rank them just by directly calculating their similarities, ignoring the semantic gap between them. In this paper, we propose a novel Structure-sensitive Semantic Matching(SSM) approach that learns aligned representations of dependencies in questions and query graphs to eliminate their gap. First, we propose a cross-structure matching module to bridge the gap between two modalities(i.e., textual question and query graph). Then, we propose an entropy-based gated AQG filter to remove the structural noise caused by the uncertainty of dependencies. Finally, we present a two-channel query graph representation that fuses the semantics of abstract structure and grounding content of the query graph explicitly. Experimental results show that SSM could learn aligned representations of questions and query graphs to eliminate the gaps between their dependencies, and improves up to 12% (F1 score) on aggregation questions of two benchmark datasets.     

Word-Level Parallel Architecture of JPEG 2000 Embedded Block Coding Decoder

This paper presents a word-level decoding architecture of embedded block coding in JPEG 2000. This architecture decodes one coefficient per cycle based on the proposed word-level decoding algorithm. This algorithm eliminates state variable memories by decoding all bit-planes in parallel. The proposed column- switching scan order overcomes intra bit-plane dependency and inter bit-plane dependency to enable parallel processing. Implementation results show that the proposed architecture is capable of decoding 54 MSamples/s at 54 MHz, which can support HDTV 720p (1280 times 720, 4:2:2) decoding at 30 frames/s.