Sophisticated dependability analysis techniques are being developed in academia and research labs, but few have gained wide acceptance in industry. To be valuable, such techniques must be supported by usable, dependab...
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Sophisticated dependability analysis techniques are being developed in academia and research labs, but few have gained wide acceptance in industry. To be valuable, such techniques must be supported by usable, dependable software tools. We present our approach to addressing these issues in developing a dynamic fault tree analysis tool called Galileo. Galileo is designed to support efficient system-level analysis by automatically decomposing fault trees into modules that are solved separately using appropriate techniques. Usability is addressed by a software architecture based on a component-based design technique that we call package-oriented programming. We integrate multiple, volume-priced mass-market software packages to provide the bulk of the tool superstructure. To address tool dependability, we are developing natural language and partial formal specifications of fault tree elements, and we exploit the inherent redundancy associated with multiple analysis techniques as an aid in testing.
this paper deals with a branching time temporal query language called Min-max CTL which is similar in syntax to the popular temporal logic, CTL according to E. M. Clarke (1986). Min-max CTL can express timing queries ...
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this paper deals with a branching time temporal query language called Min-max CTL which is similar in syntax to the popular temporal logic, CTL according to E. M. Clarke (1986). Min-max CTL can express timing queries on a timed model, whereas CTL is used for untimed systems. Interesting timing queries involving a combination of min and max can be expressed in Min-max CTL. While model checking using most timed temporal logics is PSPACE complete or harder described by R. Alur and T. A. Henzinger (1993) and R. Alur et al. (1993), it is shown in the work of P. Dasgupta et al. (2001) that many practical timing queries, where we are interested in the worst case or best case timings, can be answered in polynomial time by querying the system using Min-max CTL. In this paper, the syntax of Min-max CTL is extended to increase the expressive power of Min-max CTL.
Use case point (UCP) method has been proposed to estimate software development effort in early phase of software project and used in a lot of software organizations. Intuitively, UCP is measured by counting the number...
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Use case point (UCP) method has been proposed to estimate software development effort in early phase of software project and used in a lot of software organizations. Intuitively, UCP is measured by counting the number of actors and transactions included in use case models. Several tools to support calculating UCP have been developed. However, they only extract actors and use cases and the complexity classification of them are conducted manually. We have been introducing UCP method to software projects in Hitachi Systems & Services, Ltd. To effective introduction of UCP method, we have developed an automatic use case measurement tool, called U-EST. this paper describes the idea to automatically classify the complexity of actors and use cases from use case model. We have also applied the U-EST to actual use case models and examined the difference between the value by the tool and one by the specialist. As the results, UCPs measured by the U-EST are similar to ones by the specialist.
A seamless and intuitive data reduction capability for the vast amount of scientific metadata generated by experiments is critical to ensure effective use of the data by domain specific scientists. the portal environm...
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ISBN:
(纸本)9780769540399
A seamless and intuitive data reduction capability for the vast amount of scientific metadata generated by experiments is critical to ensure effective use of the data by domain specific scientists. the portal environments and scientific gateways currently used by scientists provide search capability that is limited to the pre-defined pull-down menus and conditions set in the portal interface. Currently, data reduction can only be effectively achieved by scientists who have developed expertise in dealing with complex and disparate query languages. A common theme in our discussions with scientists is that data reduction capability, similar to web search in terms of ease-of-use, scalability, and freshness/accuracy of results, is a critical need that can greatly enhance the productivity and quality of scientific research. Most existing search tools are designed for exact string matching, but such matches are highly unlikely given the nature of metadata produced by instruments and a user’s inability to recall exact numbers to search in very large datasets. this paper presents research to locate metadata of interest within a range of values. To meet this goal, we leverage the use of XML in metadata description for scientific datasets, specifically the NeXus datasets generated by the SNS scientists. We have designed a scalable indexing structure for processing data reduction queries. Web semantics and ontology based methodologies are also employed to provide an elegant, intuitive, and powerful free-form query based data reduction interface to end users.
Many real-world applications feature data accesses on periodic domains. Manually implementing the synchronizations and communications associated to the data dependences on each case is cumbersome and error-prone. It i...
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Many real-world applications feature data accesses on periodic domains. Manually implementing the synchronizations and communications associated to the data dependences on each case is cumbersome and error-prone. It is increasingly interesting to support these applications in high-level parallel programminglanguages or parallelizing compilers. In this paper, we present a technique that, for distributed-memory systems, calculates the specific communications derived from data-parallel codes with or without periodic boundary conditions on affine access expressions. It makes transparent to the programmer the management of aggregated communications for the chosen data partition. Our technique moves to runtime part of the compile-time analysis typically used to generate the communication code for affine expressions, introducing a complete new technique that also supports the periodic boundary conditions. We present an experimental study to evaluate our proposal using several study cases. Our experimental results show that our approach can automatically obtain communication codes as efficient as those found in MPI reference codes, reducing the development effort.
In recent years, blockchain technology has become widespread, and there are now many related open source blockchain projects and services around the world. However, although blockchains are based on decentralized mech...
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ISBN:
(纸本)9781538626344;9781538626337
In recent years, blockchain technology has become widespread, and there are now many related open source blockchain projects and services around the world. However, although blockchains are based on decentralized mechanisms, the permission management of current systems is privileged and can only be accessed by users with "admin" authority, who (in turn) manage all of the general users. therefore, current blockchain structures are not ideal because most users cannot take full advantage of their features, and current access control methods cannot safeguard against compromised admins. Withthose points in mind, this paper proposes a novel method for decentralized authority management in blockchains that is based on Montesquieu's the Spirit of the Laws. the results of a simulation using the proposed method written in the Prolog programming language are also demonstrated.
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