1,185,191 research outputs found

    International Conference on Irrigation Management Transfer, Wuhan, China, 20-24 September 1994. Vol.3. Draft conference papers.

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    Irrigation managementIrrigation systemsFarmer participationPrivatizationSocial aspectsFarmers' associationsWater users' associationsTrainingPolicyFarmer participationEconomic aspectsFarmer managed irrigation systemsIrrigation programsRehabilitationWater resource management

    International Conference on Irrigation Management Transfer, Wuhan, China, 20-24 September 1994. Vol.2. Draft conference papers.

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    IndonesiaAustraliaIndiaSri LankaNigeriaVietnamBangladeshDominican RepublicTanzaniaNigerPhilippinesColombiaEgyptUzbekistanPeruNepalMexicoThailandIrrigation managementDamsLocal managementPrivatizationWater users' associationsWater distributionCanal irrigationTube well irrigationSocial aspectsFarmers' associationsLand reformSustainability

    International Conference on Irrigation Management Transfer, Wuhan, China, 20-24 September 1994. Vol. 1. Draft conference papers.

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    Irrigation managementDamsLocal managementPrivatizationWater users' associationsCase studiesTube wellsIrrigation designLarge scale systemsPerformanceCost recoveryUser chargesSustainability

    Hardware Certification for Real-time Safety-critical Systems: State of the Art

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    This paper discusses issues related to the RTCA document DO-254 Design Assurance Guidance for Airborne Electronic Hardware and its consequences for hardware certification. In particular, problems related to circuits’ compliance with DO-254 in avionics and other industries are considered. Extensive literature review of the subject is given, including current views on and experiences of chip manufacturers and EDA industry with qualification of hardware design tools, including formal approaches to hardware verification. Some results of the authors’ own study on tool qualification are presented

    Are Wireless Sensors Feasible for Aircraft?

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    Wireless communications is a preferred way of data transmission in many aerospace applications. Replacing some aircraft sensor wiring with wireless communications is a highly desirable but challenging transformation. The related sensors are referred to as aerospace wireless sensors (AWSs). This replacement can lower the weight of aircraft wiring, improve the overall safety of aircraft, simplify the design of aircraft structures, and lower the sensor installation and maintenance cost. The major concern for using AWSs is the potential negative effects on overall reliability and safety of aircraft. In this paper, the feasibility of using AWSs is discussed. In particular, the appropriate wireless communication schemes are studied in terms of immunity to jamming signals, interference to other on-board wireless systems, simultaneous data transmission from multiple AWSs, and low detectability to unintended parties. We conclude that the code-division multiple-access (CDMA) is a suitable scheme for this application

    Graduate Curricula in Software Engineering and Software Assurance: Need and Recommendations

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    In discussions about the development and use of computer systems and software products, the term “professional software engineer” is used repeatedly. In the last two decades there has been significant effort devoted to enhancing and advancing the state of professional software engineering (SwE) – new software engineering processes, methods, tools, and practices; creation of a software engineering body of knowledge [1]; development of a code of ethics and professional conduct [2], and software certification and licensing programs [3] . In 1989 the Software Engineering Institute (SEI) of Carnegie Mellon University published a landmark report on graduate education in software engineering [4]. The guidelines in that report were used by several universities in establishing graduate software engineering degree programs that helped address the problem of improving professional software engineering. Since then, software’s scale, complexity, and criticality have accelerated; yet, until recently, no significant effort has been made to revisit and update the original SEI guidelines. This paper discusses two related efforts to provide guidance about improving professional software engineering through graduate education: a project which produced the Graduate Software Engineering 2009 (GSwE2009): Curriculum Guidelines for Graduate Degree Programs in Software Engineering [5] and a current SEI project which is developing a Master of Software Assurance Reference Curriculum (MSwA2010)

    Keeping the Skies Safe

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    Professors Massood Towhidnejad and Andrew Kornecki shine a light on how their lab is helping government and the aviation industry to enhance the safety and security of software-intensive systems

    Development of a Master of Software Assurance Reference Curriculum

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    The Next Generation Air Traffic Management system (NextGen) is a blueprint of the future National Airspace System. Supporting NextGen is a nation-wide Aviation Simulation Network (ASN), which allows integration of a variety of real-time simulations to facilitate development and validation of the NextGen software by simulating a wide range of operational scenarios. The ASN system is an environment, including both simulated and human-in-the-loop real-life components (pilots and air traffic controllers).Real Time Distributed Simulation (RTDS) developed at Embry-Riddle Aeronautical University, a suite of applications providing low and medium fidelity en-route simulation capabilities, is one of the simulations contributing to the ASN. To support the interconnectivity with the ASN, we designed and implemented a dedicated gateway acting as an intermediary, providing logic for two-way communication and transfer messages between RTDS and ASN and storage for the exchanged data. It has been necessary to develop and analyze safety/security requirements for the gateway software based on analysis of system assets, hazards, threats and attacks related to ultimate real-life future implementation. Due to the nature of the system, the focus was placed on communication security and the related safety of the impacted aircraft in the simulation scenario. To support development of safety/security requirements, a well-established fault tree analysis technique was used. This fault tree model-based analysis, supported by a commercial tool, was a foundation to propose mitigations assuring the gateway system safety and security

    Measuring Security: A Challenge for the Generation

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    This paper presents an approach to measuring computer security understood as a system property, in the category of similar properties, such as safety, reliability, dependability, resilience, etc. First, a historical discussion of measurements is presented, beginning with views of Hermann von Helmholtz in his 19th century work “Zählen und Messen”. Then, contemporary approaches related to the principles of measuring software properties are discussed, with emphasis on statistical, physical and software models. A distinction between metrics and measures is made to clarify the concepts. A brief overview of inadequacies of methods and techniques to evaluate computer security is presented, followed by a proposal and discussion of a practical model to conduct experimental security measurements
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