The concept of a simulation environment combines different aspects of the simulation process into one complete powerful tool. The environment should provide the necessary state-of-the-art advances and concepts that a ...
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ISBN:
(纸本)9780780321090
The concept of a simulation environment combines different aspects of the simulation process into one complete powerful tool. The environment should provide the necessary state-of-the-art advances and concepts that a modeler may require during the simulation development and execution process. The "environment" requirements must address the end user needs while minimizing the necessity of learning a new language. The requirements must specify the useful features, independent of different platforms and implementation languages. Hence the opportunity exists for standardization of environments. The paper opens a discussion on challenges and rewards awaiting the simulation community with the advent of a standard environment.
When analysing hard real-time systems for their performance properties, most scheduling models either ignore the timing characteristics of the underlying run-time support kernel entirely or have a very simple model of...
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A model-based formal specification directed software testing approach is presented. It provides a test oracle and introduces a new coverage criterion for the functional (black-box) testing based on formal specificatio...
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A model-based formal specification directed software testing approach is presented. It provides a test oracle and introduces a new coverage criterion for the functional (black-box) testing based on formal specifications. Given the source code of an implementation, its formal specification, and the retrieve functions, a test driver can be generated to conduct, evaluate, and measure the functional test. Although the complete specification conformance of an implementation cannot be established by testing alone, our approach provides a strong necessary condition of complete specification conformance.< >
In a federated database environment, different constituents of the federation may use different temporal models or physical representations for temporal information. This paper introduces a new concept, called a tempo...
ISBN:
(纸本)9780897915922
In a federated database environment, different constituents of the federation may use different temporal models or physical representations for temporal information. This paper introduces a new concept, called a temporal module, to resolve these differences, or mismatches, among the constituents. Intuitively, a temporal module hides the implementation details of a temporal relation by exposing its information only through two windowing functions: The first function associates each time point with a set of tuples and the second function links each tuple to a set of time points. A calculus-style language is given to form queries on temporal *** modules are then extended to resolve another type of mismatch among the constituents of a federation, namely, the mismatch involving different time units (e.g., month, week and day) used to record temporal information. Our solution relies on “information conversions” provided by each constituent. Specifically, each temporal module is extended to provide several “windows” to its information, each in terms of a different time unit. The first step to process a query addressed to the federation is to select suitable windows to the underlying temporal modules. In order to facilitate such a process, time units are formally defined and studied. A federated temporal database model and its query language are proposed. The query language is an extension of the above calculus-style language.
In a federated database environment, different constituents of the federation may use different temporal models or physical representations for temporal information. This paper introduces a new concept, called a tempo...
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Several commercial processors, including the Motorola 88110 and the DEC Alpha, are capable of issuing multiple operations per clock cycle. Optimization of the pipeline depth and number of function units in these proce...
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Several commercial processors, including the Motorola 88110 and the DEC Alpha, are capable of issuing multiple operations per clock cycle. Optimization of the pipeline depth and number of function units in these processors has been largely ignored due to limited semiconductor resources. Recently, advances in feature size and packaging technologies have removed these limitations. It is possible that next-generation processor designs may benefit from multiple function unit copies and optimize pipeline depths. The paper investigates the feasibility of performing synthesis at the architectural specification level. The design space is optimized for performance constrained by a hardware model of silicon area. The results of this study indicate that cost-effective high performance can be achieved with the addition of small amounts of function unit duplication. These results are also used to comment on the validity of the "benchmark suite" approach to performance evaluation and machine design.< >
High-Level software Synthesis (HLSS) is an advanced model-based, product-line-oriented software development process being developed by the software Productivity Consortium (Consortium). The HLSS process is based upon ...
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As technology advances and our dependency on software increases, the requirement to develop the correct means to improve quality in both the deveiopment phase and the maintenance phase of software life cycle support b...
As technology advances and our dependency on software increases, the requirement to develop the correct means to improve quality in both the deveiopment phase and the maintenance phase of software life cycle support becomes increasingly significant. The focus of this paper is on the dilemma facing softwareengineering in maintaining quality within the constraints of the maintenance phase. The paper further proposes that the software maintenance process can also be analvzed and improved using statistical process control (SPC) techniques. The methods discussed in this paper have been proposed for use in the software Maintenance project at NUWC Detachment Norfolk. Upon successful testing at NUWC Detachment Norfolk, they will be forwarded to the AN/SQQ-89(V) (interagencv) software Quality Evaluation Committee for use by other agencies which are developing and maintaining AN/SQQ-89(V) software.
The Flooding Casualty Control software (FCCS) was developed under the auspices of the Naval Sea systems Command (NavSea) and is currently being deployed on a variety of ships in the neets of both the U.S. Navy and the...
The Flooding Casualty Control software (FCCS) was developed under the auspices of the Naval Sea systems Command (NavSea) and is currently being deployed on a variety of ships in the neets of both the U.S. Navy and the U.S. Coast Guard. The primary objective of FCCS is to enable damage control personnel to identify critical stability conditions, especially when related to the loss of reserve buoyancy due to battle damage and the destabilizing effects of large quantities of firefighting water, in a timely manner. FCCS was initially deploved in 1990. It utilizes the standard algorithms of the Ship Hull Characteristics Program (SHCP). The user interface was designed to allow quick familiarity for shipboard users, primarily the damage control assistant (DCA) and his staff. Intact stability evaluations include the effects of topside icing, high winds, personnel crowding, heavy lifts over the side, high speed turns, and towing. FCCS also supports ballasting analysis for amphibious ships as well as providing bottom reaction and beached stability data for grounding incidents. Bv providing a tool for the ''fuel king'' and DCA to generate the required daily updates on the current ship load and liquids status, FCCS is assured of an accurate baseline in the event of damage. The design allows the evaluation of the ultimate ship stability status for a damage event using simple compartmentation and flooding status inputs. Evaluation of the adequacy of resulting stabilitv, as well as identification of such critical stability parameters as off center loading, margin line immersion, and negative GM, are accomplished by the program. Guidance is provided for the user to initiate appropriate flooding related damage control activities. Initially fitted on USS Oliver Hazard Perry Class frigates, FCCS databases have been for the USCG Hamilton class high endurance cutters, USS Arleigh Burke class Aegis destroyers, and a variety of other U.S. Navy and U.S. Coast Guard ship classes. The progra
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