A novel specification driven and constraints solving based method to automatically generate test programs from simple to complex ones for advanced microprocessors is presented in this paper. Our microprocessor archite...
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A novel specification driven and constraints solving based method to automatically generate test programs from simple to complex ones for advanced microprocessors is presented in this paper. Our microprocessor architectural automatic test program generator (MA/sup 2/TG) can produce not only random test programs but also a sequence of instructions for a specific constraint by specifying a user constraints file. The proposed methodology makes three important contributions. First, it simplifies the microprocessor architecture modeling and eases adoption of architecture modification via architecture description language (ADL) specification. Second, it generates test programs for specific constraints utilizing the power of state-to-art constraints solving techniques. Finally, the number of test program for microprocessor verification and the verification time are dramatically reduced. We applied this method on DLX processor to illustrate the usefulness of our approach.
The goal of this paper is the optimization of the design of electrical wheels. For this, a new approach that automatically generates the optimization software is used. It allows the design to be made with an elaborate...
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The goal of this paper is the optimization of the design of electrical wheels. For this, a new approach that automatically generates the optimization software is used. It allows the design to be made with an elaborated analytical model of the structure chosen for the wheel. Thus it is possible to obtain a very efficient optimization program. This approach is illustrated using the example of an electrical wheel for a bicycle.
Statecharts have been used as a means to communicate behaviors in a precise manner between system engineers and software engineers. Hand-translating a statechart to code, as done on some previous space missions, intro...
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Statecharts have been used as a means to communicate behaviors in a precise manner between system engineers and software engineers. Hand-translating a statechart to code, as done on some previous space missions, introduces the possibility of errors in the transformation from chart to code. To improve auto-coding, we have developed a process that generates flight code from UML statecharts. Our process is being used for the flight software on the Space Interferometer Mission (SIM)
In object classes developed using design-by-contract, contracts contain assertions that formalise pre-conditions, post-conditions and invariants. To be sure that contracts are complete, they can be derived from specif...
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In object classes developed using design-by-contract, contracts contain assertions that formalise pre-conditions, post-conditions and invariants. To be sure that contracts are complete, they can be derived from specifications. For classes in a data structure library, equational specifications are appropriate. However, a conventional equational specification cannot usually be mapped directly to contracts. Instead, a second, contract-oriented, equational specification can be devised, with two key properties: it can be proved that the contract-oriented specification implies the original specification; and the contract-oriented specification can be mapped systematically to contracts. These two properties combine to increase the confidence that the contracts capture the same abstraction as the equational specification.
The design of intricate real-time systems typically involves several notations that describe the system at different levels of abstraction. Graphical notations inspired by timing diagrams are helpful at the requiremen...
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The design of intricate real-time systems typically involves several notations that describe the system at different levels of abstraction. Graphical notations inspired by timing diagrams are helpful at the requirements level, structured automata are common at the design level and dedicated languages are used at the programming level. The question arises how these different notations are linked together in a semantically meaningful way. The author argues that a logic-based approach is making a real contribution.
Summary form only given. The space-time autocoding effect implies that arbitrarily reliable communication is possible within a single coherence interval in Rayleigh flat fading as the symbol-duration of the coherence ...
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ISBN:
(纸本)0780371232
Summary form only given. The space-time autocoding effect implies that arbitrarily reliable communication is possible within a single coherence interval in Rayleigh flat fading as the symbol-duration of the coherence interval and the number of transmit antennas grow simultaneously. For relatively short (e.g., 16-symbol) coherence intervals, a codebook of isotropically random unitary space-time signals theoretically supports transmission rates that are a significant fraction of autocapacity with an extremely low probability of error. However a constellation of the required size (typically L=2/sup 80/) is impossible to generate and store, and due to lack of structure there is little hope of finding a fast decoding scheme. We propose a random, but highly structured, constellation that is completely specified by log/sub 2/ L independent isotropically distributed unitary matrices. The distinguishing property of this construction is that any two signals in the constellation are pairwise statistically independent and isotropically distributed. Thus, the pairwise probability of error, and hence the union bound on the block probability of error, of the structured constellation is identical to that of a fully random constellation of independent signals.
Understanding manipulative hand movements is a critical step toward automatic programming of dexterous robot hands, which, given their large number of degrees of freedom, are difficult to program. Our working hypothes...
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Understanding manipulative hand movements is a critical step toward automatic programming of dexterous robot hands, which, given their large number of degrees of freedom, are difficult to program. Our working hypothesis is that the units of manipulative hand movements are coordinated patterns of movement, and that most of the stable patterns of coordination are either in-phase (zero relative phase) or anti-phase (half-a-cycle relative phase). The phase-plane trajectories projected by these patterns of coordination are straight lines, with either positive or negative slope, respectively. In this paper we develop and demonstrate a method for segmenting the phase-plane trajectories, and thereby the movement, accordingly.
We claim that the role of the decision maker in a DSS is to control a heuristic search. In this context, the models involved in a DSS naturally appear as evaluation functions driving the end-user control. This interpr...
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We claim that the role of the decision maker in a DSS is to control a heuristic search. In this context, the models involved in a DSS naturally appear as evaluation functions driving the end-user control. This interpretation, which seems to be natural for P. Humphreys' (1989) lower representation levels, highlights the links between models and control and explains the prominent role of the "what if" concept in the DSS literature of the seventies. The focus now however, is rather on modelling, and will turn to the control which is related to flexibility. Hence, our analysis paves the way to the design of more flexible knowledge-based or "intelligent" DSSs. We moreover examine the difficult question of the decision support for higher representation levels.< >
The author outlines a taxonomy of methods that identifies some of the discriminating characteristics of the kinds of methods expert systems use and that suggests how methods can be mapped onto tasks. It is suggested t...
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The author outlines a taxonomy of methods that identifies some of the discriminating characteristics of the kinds of methods expert systems use and that suggests how methods can be mapped onto tasks. It is suggested that half-weak methods are an important class of methods because they can have a quite broad scope of applicability, but provide substantially more help than the weak methods do in specifying what task-implementation knowledge needs to be collected to perform a particular task and how that knowledge is appropriately represented. It is claimed that it should be possible to devise a set of inference engines (half-weak methods), each of which defines the roles that the task-implementation knowledge it requires must play and the form in which that knowledge is to be encoded. Two half-weak methods, MOLE and SALT, are considered in support of these points.< >
A control scheme for unity power factor automatic current shapers operating in discontinuous conduction mode uses constant-frequency peak current mode programming instead of the conventional low-bandwidth voltage mode...
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A control scheme for unity power factor automatic current shapers operating in discontinuous conduction mode uses constant-frequency peak current mode programming instead of the conventional low-bandwidth voltage mode programming control. The main advantage is that an input current with very low harmonic distortion (THD<1.5%) can be obtained. A potential stability problem of the control is identified and an elegant solution suggested.
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