In this paper, we analyze the data extracted from several open source software repositories. We observe that the change data follows a Zipf distribution. Based on the extracted data, we then develop three probabilisti...
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ISBN:
(纸本)1595933972
In this paper, we analyze the data extracted from several open source software repositories. We observe that the change data follows a Zipf distribution. Based on the extracted data, we then develop three probabilistic models to predict which files will have changes or bugs. the first model is Maximum Likelihood Estimation (MLE), which simply counts the number of events, i.e., changes or bugs, that happen to each file and normalizes the counts to compute a probability distribution. the second model is Reflexive Exponential Decay (RED) in which we postulate that the predictive rate of modification in a file is incremented by any modification to that file and decays exponentially. the third model is called RED-Co-Change. With each modification to a given file, the RED-Co-Change model not only increments its predictive rate, but also increments the rate for other files that are related to the given file through previous co-changes. We then present an information-theoretic approach to evaluate the performance of different prediction models. In this approach, the closeness of model distribution to the actual unknown probability distribution of the system is measured using cross entropy. We evaluate our prediction models empirically using the proposed information-theoretic approach for six large open source systems. Based on this evaluation, we observe that of our three prediction models, the RED-Co-Change model predicts the distribution that is closest to the actual distribution for all the studied systems. Copyright 2006 ACM.
Nowadays, process oriented software systems, like many business information systems, don9;t exist only in one single version, but in many variants for better coverage of the target market. Until now, the correspond...
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Nowadays, process oriented software systems, like many business information systems, don't exist only in one single version, but in many variants for better coverage of the target market. Until now, the corresponding customization has to be done manually, which is a time-consuming and error-prone task, which could be realized much more efficiently by applying process family engineering techniques. Process family engineering is a modern software development approach, which allows for the rapid and cost-effective development and deployment of customer tailored process oriented systems. In this paper we present our findings in the area of process family architectures for e-business systems, described as variant-rich process models in the Business Process Modeling Notation. We moreover address variability implementation issues using Java variability mechanisms and code generators.
In this paper, we propose a architecture of Genetic Algorithms (GAs)-based Polynomial Neural Networks(PNN), discuss a comprehensive design methodology and carry out a series of numeric experiments. GA-based design pro...
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ISBN:
(纸本)3540366679
In this paper, we propose a architecture of Genetic Algorithms (GAs)-based Polynomial Neural Networks(PNN), discuss a comprehensive design methodology and carry out a series of numeric experiments. GA-based design procedure at each stage (layer) of PNN leads to the selection of preferred nodes (or PNs) with optimal parameters (such as the number of input variables, input variables, and the order of the polynomial) available within PNN. A detailed design procedure is discussed in detail. To evaluate the performance of the GA-based PNN, the model is experimented with by using Medical Imaging System (MIS) data for application to Multi-variable software process. A comparative analysis shows that the proposed GA-based PNN is model with higher accuracy as well as more superb predictive capability than other intelligent models presented previously.
In this paper, a statistic language model is put forward to predict the next inputting word to improve the performance of the input method. So this paper constructs a general language model and a user language model, ...
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ISBN:
(纸本)076952611X
In this paper, a statistic language model is put forward to predict the next inputting word to improve the performance of the input method. So this paper constructs a general language model and a user language model, and then combines them into a new language model which was called as dynamic and self-study language model. Using the general language model in our experiment, the average length of input codes (ALIC) is reduced from 2.557 to 2.479 and the hit rate Of first characters (HRFC) is also improved from 78.704% to 96.202%. Using the dynamic and self-study language model in our experiment, when the number of inputted Chinese characters is less then 20 thousand, the HRFC increases rapidly, while the ALIC reduces rapidly. And when the number is greater than 20 thousand, the HRFC and ALIC become steady. thus it's clear that dynamic and self-study language model performs well in input method. Otherwise, we provide a modified Church-Gale smoothing method to reduce the size of general language model. this method can reduce the size to 5 percent in order to fit the request of handheld device.
Component-based Development (CBD) is an important emerging topic in softwareengineering, promising long sought after benefits like increased reuse and reduced time-to-market (and hence software production cost). Howe...
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ISBN:
(纸本)1595933751
Component-based Development (CBD) is an important emerging topic in softwareengineering, promising long sought after benefits like increased reuse and reduced time-to-market (and hence software production cost). However, there are at present many obstacles to overcome before CBD can succeed. For one thing, CBD success is predicated on a standardised market place for software components, which does not yet exist. In fact currently CBD even lacks a universally accepted terminology. Existing component models adopt different component definitions and composition operators. therefore much research remains to be done. We believe that the starting point for this endeavour should be a thorough study of current component models, identifying their key characteristics and comparing their strengths and weaknesses. A desirable side-effect would be clarifying and unifying the CBD terminology. In this tutorial, we present a clear and concise exposition of all the current major software component models, including a taxonomy. the purpose is to distill and present knowledge of current software component models, as well as to present an analysis of their properties with respect to commonly accepted criteria for CBD. the taxonomy also provides a starting point for a unified terminology.
Web services, together with service-oriented architectures, are promising integration technology to facilitate legacy system Webification and evolution. However, a service-oriented re-engineering process is still esse...
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ISBN:
(纸本)0769527183
Web services, together with service-oriented architectures, are promising integration technology to facilitate legacy system Webification and evolution. However, a service-oriented re-engineering process is still essential for legacy systems to survive in the service-oriented computing environment. In this service-oriented re-engineering process, understanding and reusing object-oriented code turn to be important activities. In this paper, we proposed a comprehensive approach to support the extraction and integration of reusable object-oriented legacy code. In the extraction phase, formal concept analysis, which is a general and flexible technique for recovering structural design information, and inter-procedural program slicing are adopted as main reverse engineering techniques to recover reusable object-oriented code. In the integration phase, service packaging processes are presented in details. Our approach produces extracted components with core legacy object-oriented code function in Web services by wrapping underlying computing models with XML.
Aspect-oriented concepts are currently introduced in all phases of the software development life cycle. However the complexity, of interactions among different aspects and between aspects and base entities may reduce ...
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ISBN:
(纸本)0769525555
Aspect-oriented concepts are currently introduced in all phases of the software development life cycle. However the complexity, of interactions among different aspects and between aspects and base entities may reduce the value of aspect-oriented separation of cross-cutting concerns. Some interactions may be intended or may be emerging behavior, while others are the source of unexpected inconsistencies. It is therefore desirable to detect inconsistencies as early as possible, preferably at the modeling level. We propose an approachfor analyzing interactions and potential inconsistencies at the level of requirements modeling. We use a variant of UML to model requirements in a use case driven approach. Activities that are used to refine use cases are the join points to compose crosscutting concerns. the activities and their composition are formalized using the theory of graph transformation systems, which provides analysis support for detecting potential conflicts and dependencies between rule-based transformations. this theory is used to effectively reason about potential interactions and inconsistencies caused by aspectoriented composition. the analysis is performed withthe graph transformation tool AGG. the automatically analyzed conflicts and dependencies also serve as an additional view that helps in better understanding the potential behavior of the composed system.
Feature Oriented Programming (FOP) is a design methodology and tools for program synthesis in software product lines. Programs are specified declarad vely in terms of features. FOP has been used to develop product-lin...
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the development of Behavioral Dependency Analysis (BDA) techniques and the visualization of such dependencies have been identified as a high priority in industrial Distributed Real-Time Systems (DRTS). BDA determines ...
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ISBN:
(纸本)3540457720
the development of Behavioral Dependency Analysis (BDA) techniques and the visualization of such dependencies have been identified as a high priority in industrial Distributed Real-Time Systems (DRTS). BDA determines the extent to which the functionality of one system entity (e.g., an object, a node) is dependent on other entities. Among many uses, a BDA is traditionally used to perform risk analysis and assessment, fault tolerance and redundancy provisions (e.g. multiple instances of a system entity) in DRTS. Traditionally, most BDA techniques are based on source code or execution traces of a system. However, as model driven development is gaining more popularity, there is a need for model-based BDA techniques. To address this need, we propose a set of procedures and measures for the BDA of distributed objects based on behavioral models (UML sequence diagrams). In contrast to the conventional code-based and execution-trace-based BDA techniques, this measure can be used earlier in the software development life cycle, when the UML design model of a system becomes available, to provide engineers with early insights into dependencies among entities in a DRTS (e.g., early risk identification). We also present a dependency visualization model to visualize measured dependencies. Our approach is applied to a case study to show its applicability and potential usefulness in predicting behavioral dependencies based on UML models.
this paper presents the Pattern Modeling Framework (PMF), a new metamodeling approach to pattern specification for MOF-compliant modeling frameworks and languages. Patterns need to be precisely specified before a tool...
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ISBN:
(纸本)3540457720
this paper presents the Pattern Modeling Framework (PMF), a new metamodeling approach to pattern specification for MOF-compliant modeling frameworks and languages. Patterns need to be precisely specified before a tool can manipulate them, and though several approaches to pattern specification have been proposed, they do not provide the scalability and flexibility required in practice. PMF provides a pattern specification language called Epattern, which is capable of precisely specifying patterns in MOF-compliant metamodels. the language is defined as an extension to MOF by adding semantics inspired from the UML composite structure diagram. the language also comes with a graphical notation and a recommended iterative specification process. It also contains features to manage the complexity of specifying patterns and simplify their application and detection in user models. Most importantly, the language is implemented using state-of-the-art technologies that are heavily used by major modeling tool vendors, thus facilitating its adoption.
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