34,827 research outputs found
An Institutional Framework for Heterogeneous Formal Development in UML
We present a framework for formal software development with UML. In contrast
to previous approaches that equip UML with a formal semantics, we follow an
institution based heterogeneous approach. This can express suitable formal
semantics of the different UML diagram types directly, without the need to map
everything to one specific formalism (let it be first-order logic or graph
grammars). We show how different aspects of the formal development process can
be coherently formalised, ranging from requirements over design and Hoare-style
conditions on code to the implementation itself. The framework can be used to
verify consistency of different UML diagrams both horizontally (e.g.,
consistency among various requirements) as well as vertically (e.g.,
correctness of design or implementation w.r.t. the requirements)
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Technical Review of Residential Programmable Communicating Thermostat Implementation for Title 24-2008
KBS for Desktop PC Troubleshooting
Abstract: Background: In spite of the fact that computers continue to improve in speed and functions operation, they remain complex to use. Problems frequently happen, and it is hard to resolve or find solutions for them. This paper outlines the significance and feasibility of building a desktop PC problems diagnosis system. The system gathers problem symptoms from users’ desktops, rather than the user describes his/her problems to primary search engines. It automatically searches global databases of problem symptoms and solutions, and also allows ordinary users to contribute exact problem reports in a structured manner. Objectives: The main goal of this Knowledge Based System is to get the suitable problem desktop PC symptoms and the correct way to solve the errors. Methods: In this paper the design of the proposed Knowledge Based System which was produced to help users of desktop PC in knowing many of the problems and error such as : Power supply problems, CPU errors, RAM dumping error, hard disk errors and bad sectors and suddenly restarting PC. The proposed Knowledge Based System presents an overview about desktop PC hardware errors are given, the cause of fault are outlined and the solution to the problems whenever possible is given out. CLIPS Knowledge Based System language was used for designing and implementing the proposed expert system. Results: The proposed PC desktop troubleshooting Knowledge Based System was evaluated by IT students and they were satisfied with its performance
Framework for a space shuttle main engine health monitoring system
A framework developed for a health management system (HMS) which is directed at improving the safety of operation of the Space Shuttle Main Engine (SSME) is summarized. An emphasis was placed on near term technology through requirements to use existing SSME instrumentation and to demonstrate the HMS during SSME ground tests within five years. The HMS framework was developed through an analysis of SSME failure modes, fault detection algorithms, sensor technologies, and hardware architectures. A key feature of the HMS framework design is that a clear path from the ground test system to a flight HMS was maintained. Fault detection techniques based on time series, nonlinear regression, and clustering algorithms were developed and demonstrated on data from SSME ground test failures. The fault detection algorithms exhibited 100 percent detection of faults, had an extremely low false alarm rate, and were robust to sensor loss. These algorithms were incorporated into a hierarchical decision making strategy for overall assessment of SSME health. A preliminary design for a hardware architecture capable of supporting real time operation of the HMS functions was developed. Utilizing modular, commercial off-the-shelf components produced a reliable low cost design with the flexibility to incorporate advances in algorithm and sensor technology as they become available
Analysis of shear test method for composite laminates
An elastic plane stress finite element analysis of the stress distributions in four flat test specimens for in-plane shear response of composite materials subjected to mechanical or thermal loads is presented. The shear test specimens investigated include: slotted coupon, cross beam, losipescu, and rail shear. Results are presented in the form of normalized shear contour plots for all three in-plane stess components. It is shown that the cross beam, losipescu, and rail shear specimens have stress distributions which are more than adequate for determining linear shear behavior of composite materials. Laminate properties, core effects, and fixture configurations are among the factors which were found to influence the stress distributions
Design criteria for a PC-based common user interface to remote information systems
A set of design criteria are presented which will allow the implementation of an interface to multiple remote information systems on a microcomputer. The focus of the design description is on providing the user with the functionality required to retrieve, store and manipulate data residing in remote information systems through the utilization of a standardized interface system. The intent is to spare the user from learning the details of retrieval from specific systems while retaining the full capabilities of each system. The system design includes multi-level capabilities to enhance usability by a wide range of users and utilizes microcomputer graphics capabilities where applicable. A data collection subsystem for evaluation purposes is also described
Amalan pentaksiran untuk pembelajaran guru-guru sekolah kluster kecemerlangan sekolah rendah zon selatan
Pentaksiran untuk pembelajaran merupakan sebahagian daripada proses pengajaran dan pembelajaran. Kajian ini bertujuan untuk mengkaji amalan pentaksiran untuk pembelajaran bagi guru-guru sekolah kluster kecemerlangan (SKK) sekolah rendah Zon Selatan Semenanjung Malaysia. Secara terperinci, ia memberi maklumat tentang tahap pemahaman konsep asas pentaksiran dalam pendidikan dan menilai amalan pentaksiran untuk pembelajaran yang dilaksanakan. Kajian juga turut menilai hubungan amalan pentaksiran untuk pembelajaran mengikut profil demografi serta menentukan sumbangan yang signifikan strategi pentaksiran untuk pembelajaran terhadap amalan pentaksiran yang dilaksanakan di bilik darjah. Kaedah kajian menggunakan pendekatan kuantitatif dan kualitatif. Pendekatan kuantitatif melibatkan kaedah tinjauan dijalankan pada fasa pertama kajian. Pendekatan kualitatif melibatkan kajian kes dijalankan pada fasa kedua untuk menyokong dan menerangkan lebih lanjut dapatan kajian fasa pertama. Pada fasa pertama seramai 152 orang guru dari 9 buah sekolah SKK sekolah rendah Zon Selatan, Semenanjung yang mengajar mata pelajaran teras iaitu Bahasa Malaysia, Bahasa Inggeris, Matematik dan Sains untuk menjawab satu set soal selidik. Pada fasa kedua seramai 8 orang guru yang terdiri daripada 4 orang guru mata pelajaran teras dan 4 orang guru yang terlibat dalam pengurusan pentaksiran dipilih berdasarkan persampelan bertujuan untuk ditemu bual dan 8 orang guru mata pelajaran teras dipilih untuk pemerhatian pengajaran. Dapatan kajian terhadap tahap pemahaman konsep asas dan tujuan pentaksiran menunjukkan tahap pemahaman yang sangat jelas. Dapatan amalan pentaksiran untuk pembelajaran berdasarkan tujuh strategi amalan pentaksiran untuk pembelajaran menunjukkan secara keseluruhannya berapa pada tahap tinggi dengan amalan yang kerap dilakukan kecuali pada strategi keempat dan ketujuh mempunyai tahap amalan yang sederhana dengan amalan sesekali sahaja dilaksanakan oleh guru-guru tersebut. Berdasarkan profil demografi, dapatan menunjukkan tidak terdapat perbezaan yang signifikan antara faktor jantina guru, pengalaman guru, dan mata pelajaran yang diajar dengan amalan pentaksiran untuk pembelajaran. Sebagai sumbangan, kajian ini mencadangkan satu panduan dan kerangka pentaksiran untuk pembelajaran yang boleh digunapakai oleh semua guru di sekolah
Multiple Benefits of Carbon-Friendly Agricultural Practices: Empirical Assessment of Conservation Tillage in Iowa
In this study, we estimate empirically the multiple benefits of a subsidy policy that would offer payments to farmers in return for the adoption of conservation tillage and compare the outcomes of alternative targeting designs for such a policy. Using data for roughly 12,000 National Resource Inventory (NRI) points, we simulate for the state of Iowa the least-cost policy schemes for offering payment incentives. We use an economic model of conservation tillage adoption to evaluate the costs of adoption, and we use a model that simulates physical processes (Environmental Policy Integrated Climate, or EPIC) to estimate the environmental benefits of adoption at each of the NRI points. We assess the costs and environmental consequences of two targeting options. The first is a practice-based policy instrument that maximizes the acres of land in conservation tillage, regardless of the level of environmental benefits achieved. The second is a performance-based instrument that yields the highest amount of environmental benefits per dollar spent. We consider four performance-based benefits: carbon sequestration in agricultural soils, reduction in nitrogen runoff, reduction of erosion of soil by wind, and reduction of erosion of soil by water. We find that the practice-based instrument provides high proportions of the four benefits relative to the performance-based instrument, especially at higher budget levels. Similarly, we estimate that targeting one of the four benefits provides high percentages of the other benefits compared to the amounts obtainable if they were targeted directly.conservation tillage, multiple benefits, subsidy policy, targeting.
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