共查询到20条相似文献,搜索用时 15 毫秒
1.
《国际计算机数学杂志》2012,89(1-4):315-345
An operational model which allows the complete formal definition of the full syntax and, particularly, semantics of programming languages is described. Both its syntactic and semantic parts are based on so-called linked-forest manipulation systems which allow the definition of mappings on forests. The idea of “linking” is crucial for the given model, we represent not only abstract programs but also intermediate states of our system (abstract computer) by labelled forests with pointers. 相似文献
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A significant impediment to the uptake of formal refinement-based methods among practitioners is the challenge of validating that the formal specifications of these methods capture the desired intents. Animation of specifications is widely recognized as an effective way of addressing such validation. However, animation tools are unable to directly execute (and thus animate) the typical uses of several of the specification constructs often found in ideal formal specifications. To address this problem, we have developed transformation heuristics that, starting with an ideal formal specification, guide its conversion into an animatable form. We show several of these heuristics and address the need to prove that the application of these transformations preserves the relevant behavior of the original specification. Portions of several case studies illustrate this approach. 相似文献
3.
Cangussu J.W. DeCarlo R.A. Mathur A.P. 《IEEE transactions on pattern analysis and machine intelligence》2002,28(8):782-796
A novel approach to model the system test phase of the software life cycle is presented. This approach is based on concepts and techniques from control theory and is useful in computing the effort required to reduce the number of errors and the schedule slippage under a changing process environment. Results from these computations are used, and possibly revised, at specific checkpoints in a feedback-control structure to meet the schedule and quality objectives. Two case studies were conducted to study the behavior of the proposed model. One study reported here uses data from a commercial project. The outcome from these two studies suggests that the proposed model might well be the first significant milestone along the road to a formal and practical theory of software process control. 相似文献
4.
由于传统工作流技术无法满足时常变更的业务过程,工作流的柔性问题成为研究的热点。从WFMC的过程定义元模型中提取出连接类型和活动状态,封装成新元素,并重定义了转移条件和角色,从而形成一种改进的柔性工作流过程定义元模型。运用工作流过程定义语言对元模型主要元素进行了形式化描述,并通过一个实例说明了该模型在实践中的柔性。 相似文献
5.
为改进传统的软件过程定义模型缺乏动态跟踪机制和专业性的缺陷,将任务和活动进行有效地结合,并引入动态跟踪机制,提出以活动为核心的过程定义模型,模型分为针对软件过程框架的EIDEF0和针对活动的BETVX,分别描述了软件过程的基本要素、过程的测量项、输入和输出以及过程间的关系;过程活动的组成要素、任务及其关系、执行活动的角色、执行者、资源和信息。模型完全符合CMMI-SW的要求,并结合工作流控制的特点,降低了实施软件过程改进和评估的成本。 相似文献
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Hume is a contemporary programming language oriented to systems with strong resource bounds, based on autonomous concurrent
“boxes” interacting across “wires”. Hume’s design reflects the explicit separation of coordination and computation aspects
of multi-process systems, which greatly eases establishing resource bounds for programs. However, coordination and computation
are necessarily tightly coupled in reasoning about Hume programs. Furthermore, in Hume, local changes to coordination or computation,
while preserving input/output correctness, can have profound and unforeseen effects on other aspects of programs such as timing
of events and scheduling of processes. Thus, traditional program calculi prove inappropriate as they tend to focus exclusively
either on the coordination of interacting processes or on computation within individual processes. 相似文献
8.
Siegfried Schönberger Rudolf K. Keller Ismail Khriss 《Concurrency and Computation》2001,13(5):351-383
Current methods for object-oriented software development provide notation for the specification of models, yet do not sufficiently relate the different model types to each other, nor do they provide support for transformations from one model type to another. This makes transformations a manual activity, which increases the risk of inconsistencies among models and may lead to a loss of information. We have developed and implemented an algorithm supporting one of the transitions from analysis to design, the transformation of scenario models into behavior models. This algorithm supports the Unified Modelling Language (UML), mapping the UML's collaboration diagrams into state transition diagrams. We believe that CASE tools implementing such algorithms will be highly beneficial in object-oriented software development. In this paper, we provide an overview of our algorithm and discuss all its major steps. The algorithm is detailed in semi-formal English and illustrated with a number of examples. Furthermore, the algorithm is assessed from different perspectives, such as scope and role in the overall development process, issues in the design of the algorithm, complexity, implementation and experimentation, and related work. Copyright © 2001 John Wiley & Sons, Ltd. 相似文献
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A year-long trial has seen a large lightweight verification problem treated by an ad hoc distributed network of identical solvers. The trialled problem is the semantic analysis of the C code in the Linux kernel to exclude a common deadlock possibility. The aim of the programme behind the experiment is to develop a viable loosely coupled distributed formal method which a community of interested part-time helpers on the net can lend their computing cycles to as they will, or send their own verification problems to for solving. 相似文献
11.
Semantic Web Service, one of the most significant research areas within the Semantic Web vision, has attracted increasing attention from both the research community and industry. The Web Service Modelling Ontology (WSMO) has been proposed as an enabling framework for the total/partial automation of the tasks (e.g., discovery, selection, composition, mediation, execution, monitoring, etc.) involved in both intra- and inter-enterprise integration of Web services. To support the standardisation and tool support of WSMO, a formal model of the language is highly desirable. As several variants of WSMO have been proposed by the WSMO community, which are still under development, the syntax and semantics of WSMO should be formally defined to facilitate easy reuse and future development. In this paper, we present a formal Object-Z formal model of WSMO, where different aspects of the language have been precisely defined within one unified framework. This model not only provides a formal unambiguous model which can be used to develop tools and facilitate future development, but as demonstrated in this paper, can be used to identify and eliminate errors present in existing documentation. 相似文献
12.
Model coupling is an important approach to studying the dynamics of complex systems, but by introducing new feedback loops, the dynamics of coupled models can be artificially distorted. This paper describes a new method of model coupling which addresses this problem through a dynamic form of regularization. The method allows the time series evolution of model variables to be mutually informed by multiple models, and models to influence each other in proportion to their degree of certainty. Uncoupled forms of the coupled models can act as dynamic priors on the trajectory of coupled variables, strengthening model stability and offering additional calibration of the coupling process. Finally, models that describe different spatial scales can be coupled into multi-scale models, so that, for example, spatially-distributed models can be coupled with aggregate models, and influence one another. We apply this technique to a coupled socio-ecological system of population growth and ecosystem harvesting. 相似文献
13.
Claudia Popien Axel Kuepper Bernd Meyer 《Journal of Network and Systems Management》1994,2(4):383-400
New requirements of growing computer networks and information systems have an influence on extended client/server models with increased functionality. This forms the basis for service management in distributed systems which is realized by a service trading concept. This paper studies the requirements derived from the Open Distributed Processing (ODP) Reference Model in order to consider an open service market. Furthermore, it examines management possibilities for describing the service trading scenario. Because of similar architectures and properties ODP services, service offers, types, exporters and traders are mapped onto management components and modeled as managed objects. Therefore, the Guidelines for the Definition of Managed Objects (GDMO) are used. The final concept allows a precise and unambiguous study of the service trading scenario and provides means for exporting and importing of service offers in a distributed environment. 相似文献
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Gyu Sang Choi Author Vitae Chita R. Das Author Vitae 《Journal of Systems and Software》2010,83(10):1823-1837
Design of high-performance servers has become a research thrust to meet the increasing demand of network-based applications. One approach to design such architectures is to exploit the enormous computing power of Multi-Core Processors (MCPs) that are envisioned to become the state-of-the-art in processor architecture. In this paper, we propose a new software architecture model, called SuperScalar, suitable for MCP machines. The proposed SuperScalar model consists of multiple pipelined thread pools, where each pipelined thread pool consists of multiple threads, and each thread takes a different role. The main advantages of the proposed model are global information sharing by the threads and minimal memory requirement due to fewer threads.We have conducted in-depth performance analyses of the proposed scheme along with three prior software architecture schemes (Multi-Process (MP), Multi-Thread (MT) and Event-Driven (ED)) via an analytical model. The performance results indicate that the proposed SuperScalar model shows the best performance across all system and workload parameters compared to the MP, MT and ED models. Although the MT model shows competitive performance with less number of processing cores and smaller data cache size, the advantage of the SuperScalar model becomes obvious as the number of processing cores increases. 相似文献
16.
Collaboration through computation: incorporating trust model into service-based software systems 总被引:1,自引:0,他引:1
Mohammad Gias Uddin Mohammad Zulkernine Sheikh Iqbal Ahamed 《Service Oriented Computing and Applications》2009,3(1):47-63
The open and dynamic nature of service-based software systems necessitates spontaneous and trustworthy interactions between
collaborating entities. Service providers are exposed to users spanned across multiple organizational domains, so can be exploited
by potentially untrustworthy service requestors. Given that, service providers need to trust requestors before granting them
with services. Trust encompasses a number of quality attributes (e.g., security, competence, honesty) and helps in dynamic
decision making. In this paper, we present a trust-based service collaboration approach, facilitated by the analysis of service-based
interactions between service providers and requestors, and recommendations between service providers. Service providers exchange
recommendations to convey their trust on requestors. This collaboration is quantified using our proposed trust model, called
CAT, a Context-Aware Trust model based on service-based interactions by considering services as contexts. We identify a number
of collaboration-based trust properties including risk and context-awareness and incorporate them in CAT. A context-similarity
parameter is introduced to decide on similar services. A time-based ageing parameter is proposed to decrease trust values
over time without any further interactions. Direct and indirect recommendations from other service providers are included
in total trust calculation, with a path-based ageing parameter applying over indirect recommendations. A mechanism to calculate
the accuracy of recommendations is proposed to differentiate between reliable and unreliable recommendations. These calculation
schemes are employed in a trust-based service collaboration algorithm to automatically decide on granting services to requestors.
The approach is elaborated using examples from file sharing applications, and successfully evaluated by implementing a prototype
service-based file sharing grid.
This research is partially funded by the Natural Sciences and Engineering Research Council of Canada (NSERC). 相似文献
17.
REquirements TRacing On target (RETRO): improving software maintenance through traceability recovery 总被引:1,自引:0,他引:1
Jane Huffman Hayes Alex Dekhtyar Senthil Karthikeyan Sundaram E. Ashlee Holbrook Sravanthi Vadlamudi Alain April 《Innovations in Systems and Software Engineering》2007,3(3):193-202
A number of important tasks in software maintenance require an up-to-date requirements traceability matrix (RTM): change impact
analysis, determination of test cases to execute for regression testing, etc. The generation and maintenance of RTMs are tedious
and error-prone, and they are hence often not done. In this paper, we present REquirements TRacing On-target (RETRO), a special-
purpose requirements tracing tool. We discuss how RETRO automates the generation of RTMs and present the results of a study
comparing manual RTM generation to RTM generation using RETRO. The study showed that RETRO found significantly more correct
links than manual tracing and took only one third of the time to do so.
Work performed while A. Dekhtyar was on the faculty at the University of Kentucky. 相似文献
18.
Isaac Lera Pere P. Sancho Carlos Juiz Ramon Puigjaner Joachim Zottl Günter Haring 《Software Quality Journal》2007,15(1):53-67
In the computer science community there is a growing interest in the field of Ambient Intelligent Systems. This systems surround
their human users with computing and networking technology unobtrusively embedded in their environment. This technology is
aimed to provide the users with useful information and to take action to make the environment more convenient for them. As
the number of users increases the resources that make Ambient Intelligence possible can be easily saturated making the system
unstable and projecting an image of poor QoS to the users. The main goal of this paper is to provide the means for the Ambient
Intelligent Systems to monitor themselves and take corrective action automatically if performance starts to drop. Our approach
uses a Performance Ontology that structures the knowledge about Software Performance Engineering, and a reasoning engine that acts like an expert system
with the Performance Ontology as its foundation. The case study at the end shows the applicability of the developed techniques. 相似文献
19.
Lars-Ola Damm Author Vitae Lars Lundberg Author Vitae 《Journal of Systems and Software》2008,81(11):1968-1982
Analysis of anomalies reported during testing of a project can tell a lot about how well the processes and products work. Still, organizations rarely use anomaly reports for more than progress tracking although projects commonly spend a significant part of the development time on finding and correcting faults. This paper presents an anomaly metrics model that organizations can use for identifying improvements in the development process, i.e. to reduce the cost and lead-time spent on rework-related activities and to improve the quality of the delivered product. The model is the result of a four year research project performed at Ericsson. 相似文献