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1.
Semantic oriented ontology cohesion metrics for ontology-based systems   总被引:1,自引:0,他引:1  
Ontologies play a core role to provide shared knowledge models to semantic-driven applications targeted by Semantic Web. Ontology metrics become an important area because they can help ontology engineers to assess ontology and better control project management and development of ontology based systems, and therefore reduce the risk of project failures. In this paper, we propose a set of ontology cohesion metrics which focuses on measuring (possibly inconsistent) ontologies in the context of dynamic and changing Web. They are: Number of Ontology Partitions (NOP), Number of Minimally Inconsistent Subsets (NMIS) and Average Value of Axiom Inconsistencies (AVAI). These ontology metrics are used to measure ontological semantics rather than ontological structure. They are theoretically validated for ensuring their theoretical soundness, and further empirically validated by a standard test set of debugging ontologies. The related algorithms to compute these ontology metrics also are discussed. These metrics proposed in this paper can be used as a very useful complementarity of existing ontology cohesion metrics.  相似文献   

2.
Heuristics for model checking Java programs   总被引:1,自引:0,他引:1  
Model checking of software programs has two goals – the verification of correct software and the discovery of errors in faulty software. Some techniques for dealing with the most crucial problem in model checking, the state space explosion problem, concentrate on the first of these goals. In this paper we present an array of heuristic model checking techniques for combating the state space explosion when searching for errors. Previous work on this topic has mostly focused on property-specific heuristics closely related to particular kinds of errors. We present structural heuristics that attempt to explore the structure (branching structure, thread interdependency structure, abstraction structure) of a program in a manner intended to expose errors efficiently. Experimental results show the utility of this class of heuristics. In contrast to these very general heuristics, we also present very lightweight techniques for introducing program-specific heuristic guidance.  相似文献   

3.
The existing cohesion metrics for classes do not consider the characteristics of dependent instance variables that are commonly used in a class and, thus, do not properly reflect the cohesiveness of the class. This paper presents an approach for improving the cohesion metrics by considering the characteristics of the dependent instance variables in an object-oriented program.  相似文献   

4.
Improving the applicability of object-oriented class cohesion metrics   总被引:1,自引:0,他引:1  

Context

Class cohesion is an important object-oriented quality attribute. It refers to the degree of relatedness between the methods and attributes of a class. Several metrics have been proposed to measure the extent to which the class members are related. Most of these metrics have undefined values for a relatively high percentage of classes, which limits their applicability. The classes that have undefined values lack methods, attributes, or parameter types, or they include only a single method.

Objective

We improve the applicability of the class cohesion metrics by defining their values for such special classes. In addition, we theoretically and empirically validate the improved metrics.

Method

We theoretically examine whether the defined values satisfy the key cohesion properties. In addition, we empirically validate the metrics before and after the improvements to test whether the defined values improve the ability of the metrics to evaluate class cohesion. We also explore the correlation between the metrics and the presence of faulty classes to indirectly determine the strength or weakness of the metrics in indicating class quality.

Results

The results show that our assigned values for the undefined cases do not violate the key cohesion properties and considerably improve the ability of the metrics to explain the presence of faulty classes and may therefore improve their ability to indicate the quality of the class design.

Conclusions

Having the class cohesion metrics defined for all possible cases improves the applicability of the metrics and potentially increases their precision in indicating class quality.  相似文献   

5.
Hall  T. Fenton  N. 《Software, IEEE》1997,14(2):55-65
Increasingly organisations are foregoing an ad hoc approach to metrics in favor of complete metrics programs. The authors identify consensus requirements for metric program success and examine how programs in two organisations measured up  相似文献   

6.
Program mutation is a fault-based technique for measuring the effectiveness of test cases that, although powerful, is computationally expensive. The principal expense of mutation is that many faulty versions of the program under test, called mutants, must be created and repeatedly executed. This paper describes a tool, called JavaMut, that implements 26 traditional and object-oriented mutation operators for supporting mutation analysis of Java programs. The current version of that tool is based on syntactic analysis and reflection for implementing mutation operators. JavaMut is interactive; it provides a graphical user interface to make mutation analysis faster and less painful. Thanks to such automated tools, mutation analysis should be achieved within reasonable costs.  相似文献   

7.
Evaluating workflow process designs using cohesion and coupling metrics   总被引:1,自引:0,他引:1  
Irene  Hajo A.  Wil M.P.   《Computers in Industry》2008,59(5):420-437
  相似文献   

8.
State-space exploration is a powerful technique for verification of concurrent software systems. Applying it to software systems written in standard programming languages requires powerful abstractions (of data) and reductions (of atomicity), which focus on simplifying the data and control, respectively, by aggregation. We propose a reduction that exploits a common pattern of synchronization, namely, the use of locks to protect shared data structures. This pattern of synchronization is particularly common in concurrent Java programs, because Java provides built-in locks. We describe the design of a new tool for state-less state-space exploration of Java programs that incorporates this reduction. We also describe an implementation of the reduction in Java PathFinder, a more traditional state-space exploration tool for Java programs. Published online: 2 October 2002 RID="*" ID="*"Present address: Computer Science Dept., SUNY at Stony Brook, Stony Brook, NY 11794-4400, USA. The author gratefully acknowledges the support of ONR under Grants N00014-99-1-0358 and N00014-01-1-0109 and the support of NSF under Grant CCR-9876058.  相似文献   

9.
随着多核处理器的发展,多线程并发程序成为现代程序设计的趋势.但并发线程的执行存在不确定性,传统的测试方法很难发现这类错误.针时这个问题,提出了一种直接分析Java源代码,从中提取并发程序模型的方法;并以此方法为基础开发了工具JTS(Java to SPIN),实现了对Java并发程序的自动化分析和模型检测.实验表明JTS能够成功地检测出Java并发程序中存在的错误并给出相应的错误路径.这项工作给Java并发程序的测试与验证提供了新的途径.  相似文献   

10.
This paper distinguishes several different approaches to organising a weakest pre-condition (WP) calculus in a theorem prover. The implementation of two of these approaches for Java within the LOOP project is described. This involves the WP-infrastructures in the higher order logic of the theorem prover PVS, together with associated rules and strategies for automatically proving JML specifications for Java implementations. The soundness of all WP-rules has been proven on the basis of the underlying Java semantics. These WP-calculi are integrated with the existing Hoare logic, and together form a verification toolkit in PVS: typically one uses Hoare logic rules to break a large verification task up into smaller parts that can be handled automatically by one of the WP-strategies.  相似文献   

11.
Safety-Critical Java (SCJ) is a novel version of Java that addresses issues related to real-time programming and certification of safety-critical applications. In this paper, we propose a technique that reveals the issues involved in the formal verification of an SCJ program, and provides guidelines for tackling them in a refinement-based approach. It is based on Circus, a combination of well established notations: Z, CSP, Timed CSP, and object orientation. We cater for the specification of timing requirements and their decomposition towards the structure of missions and event handlers of SCJ. We also consider the integrated refinement of value-based specifications into class-based designs using SCJ scoped memory areas. We present a refinement strategy, a Circus variant that captures the essence of the SCJ paradigm, and a substantial example based approach on a concurrent version of a case study that has been used as a benchmark by the SCJ community: an aircraft collision detector.  相似文献   

12.
Chen  M.K. Olukotun  K. 《Micro, IEEE》2003,23(6):26-35
As instruction-level parallelism with a single thread of control approaches its performance limits, designers must find other architectural improvements to speed up program execution. The Java runtime parallelizing machine (JRPM) system takes advantage of recent developments to enable a new approach to automatic parallelization. JRPM can exploit thread-level parallelism with minimal programmer effort.  相似文献   

13.
Software Quality Journal - Many Java programs encode temporal behaviors in their source code, typically mixing three features provided by the Java language: (1) pausing the execution for a limited...  相似文献   

14.
15.
ContextExisting fault-localization techniques combine various program features and similarity coefficients with the aim of precisely assessing the similarities among the dynamic spectra of these program features to predict the locations of faults. Many such techniques estimate the probability of a particular program feature causing the observed failures. They often ignore the noise introduced by other features on the same set of executions that may lead to the observed failures. It is unclear to what extent such noise can be alleviated.ObjectiveThis paper aims to develop a framework that reduces the noise in fault-failure correlation measurements.MethodWe develop a fault-localization framework that uses chains of key basic blocks as program features and a noise-reduction methodology to improve on the similarity coefficients of fault-localization techniques. We evaluate our framework on five base techniques using five real-life median-scaled programs in different application domains. We also conduct a case study on subjects with multiple faults.ResultsThe experimental result shows that the synthesized techniques are more effective than their base techniques by almost 10%. Moreover, their runtime overhead factors to collect the required feature values are practical. The case study also shows that the synthesized techniques work well on subjects with multiple faults.ConclusionWe conclude that the proposed framework has a significant and positive effect on improving the effectiveness of the corresponding base techniques.  相似文献   

16.
A method for an introductory optimization of multithreaded Java programs for execution on clusters of Java Virtual Machines (JVMs) inside desktop grids is presented. It is composed of two stages. In the first stage, a clustering algorithm is applied to extended macro data flow graphs generated on the basis of the byte-code compiled for multithreaded Java programs. These graphs account for data and control dependencies in programs including conditional branch instructions annotated by branch statistics driven from execution traces for representative sets of data. In the second stage, a list scheduling is performed based on the Earliest Task First (ETF) heuristics in which node mapping on JVMs accounts for mutually exclusive paths outgoing from conditional branch nodes. The presented object placement optimization algorithm is a part of the DG-ADAJ environment.  相似文献   

17.
We present a static analysis-based technique for reverse engineering finite state machine models from a large subset of sequential Java programs. Our approach enumerates all feasible program paths in a class using symbolic execution and records execution summary for each path. Subsequently, it creates states and transitions by analyzing symbolic execution summaries. Our approach also detects any unhandled exceptions.  相似文献   

18.

Context

Several metrics have been proposed to measure the extent to which class members are related. Connectivity-based class cohesion metrics measure the degree of connectivity among the class members.

Objective

We propose a new class cohesion metric that has higher discriminative power than any of the existing cohesion metrics. In addition, we empirically compare the connectivity and non-connectivity-based cohesion metrics.

Method

The proposed class cohesion metric is based on counting the number of possible paths in a graph that represents the connectivity pattern of the class members. We theoretically and empirically validate this path connectivity class cohesion (PCCC) metric. The empirical validation compares seven connectivity-based metrics, including PCCC, and 11 non-connectivity-based metrics in terms of discriminative and fault detection powers. The discriminative-power study explores the probability that a cohesion metric will incorrectly determine classes to be cohesively equal when they have different connectivity patterns. The fault detection study investigates whether connectivity-based metrics, including PCCC, better explain the presence of faults from a statistical standpoint in comparison to other non-connectivity-based cohesion metrics, considered individually or in combination.

Results

The theoretical validation demonstrates that PCCC satisfies the key cohesion properties. The results of the empirical studies indicate that, in contrast to other connectivity-based cohesion metrics, PCCC is much better than any comparable cohesion metric in terms of its discriminative power. In addition, the results also indicate that PCCC measures cohesion aspects that are not captured by other metrics, wherein it is considerably better than other connectivity-based metrics but slightly worse than some other non-connectivity-based cohesion metrics in terms of its ability to predict faulty classes.

Conclusion

PCCC is more useful in practice for the applications in which practitioners need to distinguish between the quality of different classes or the quality of different implementations of the same class.  相似文献   

19.
This paper presents an approach for the automated debugging of reactive and concurrent Java programs, combining model checking and runtime monitoring. Runtime monitoring is used to transform the Java execution traces into the input for the model checker, the purpose of which is twofold. First, it checks these execution traces against properties written in linear temporal logic (LTL), which represent desirable or undesirable behaviors. Second, it produces several execution traces for a single Java program by generating test inputs and exploring different schedulings in multithreaded programs. As state explosion is the main drawback to model checking, we propose two abstraction approaches to reduce the memory requirements when storing Java states. We also present the formal framework to clarify which kinds of LTL safety and liveness formulas can be correctly analysed with each abstraction for both finite and infinite program executions. A major advantage of our approach comes from the model checker, which stores the trace of each failed execution, allowing the programmer to replay these executions to locate the bugs. Our current implementation, the tool TJT, uses Spin as the model checker and the Java Debug Interface (JDI) for runtime monitoring. TJT is presented as an Eclipse plug-in and it has been successfully applied to debug complex public Java programs.  相似文献   

20.
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