142,908 research outputs found
Modules and Logic Programming
We study conditions for a concurrent construction of proof-nets in the
framework developed by Andreoli in recent papers. We define specific
correctness criteria for that purpose. We first study closed modules (i.e.
validity of the execution of a logic program), then extend the criterion to
open modules (i.e. validity during the execution) distinguishing criteria for
acyclicity and connectability in order to allow incremental verification
Large liquid rocket engine transient performance simulation system
Phase 1 of the Rocket Engine Transient Simulation (ROCETS) program consists of seven technical tasks: architecture; system requirements; component and submodel requirements; submodel implementation; component implementation; submodel testing and verification; and subsystem testing and verification. These tasks were completed. Phase 2 of ROCETS consists of two technical tasks: Technology Test Bed Engine (TTBE) model data generation; and system testing verification. During this period specific coding of the system processors was begun and the engineering representations of Phase 1 were expanded to produce a simple model of the TTBE. As the code was completed, some minor modifications to the system architecture centering on the global variable common, GLOBVAR, were necessary to increase processor efficiency. The engineering modules completed during Phase 2 are listed: INJTOO - main injector; MCHBOO - main chamber; NOZLOO - nozzle thrust calculations; PBRNOO - preburner; PIPE02 - compressible flow without inertia; PUMPOO - polytropic pump; ROTROO - rotor torque balance/speed derivative; and TURBOO - turbine. Detailed documentation of these modules is in the Appendix. In addition to the engineering modules, several submodules were also completed. These submodules include combustion properties, component performance characteristics (maps), and specific utilities. Specific coding was begun on the system configuration processor. All functions necessary for multiple module operation were completed but the SOLVER implementation is still under development. This system, the Verification Checkout Facility (VCF) allows interactive comparison of module results to store data as well as provides an intermediate checkout of the processor code. After validation using the VCF, the engineering modules and submodules were used to build a simple TTBE
On the anti-Yetter-Drinfeld module-contramodule correspondence
We study a functor from anti-Yetter Drinfeld modules to contramodules in the
case of a Hopf algebra . Some byproducts of this investigation are the
establishment of sufficient conditions for this functor to be an equivalence,
verification that the center of the opposite category of -comodules is
equivalent to anti-Yetter Drinfeld modules, and the observation of two types of
periodicities of the generalized Yetter-Drinfeld modules introduced previously.
Finally, we give an example of a symmetric -contratrace on -comodules
that does not arise from an anti-Yetter Drinfeld module.Comment: 32 page
Steps in modular specifications for concurrent modules
© 2015 Published by Elsevier B.V.The specification of a concurrent program module is a difficult problem. The specifications must be strong enough to enable reasoning about the intended clients without reference to the underlying module implementation. We survey a range of verification techniques for specifying concurrent modules, in particular highlighting four key concepts: auxiliary state, interference abstraction, resource ownership and atomicity. We show how these concepts combine to provide powerful approaches to specifying concurrent modules
SIM-DSP: A DSP-Enhanced CAD Platform for Signal Integrity Macromodeling and Simulation
Macromodeling-Simulation process for signal integrity verifications has become necessary for the high speed circuit system design. This paper aims to introduce a “VLSI Signal Integrity Macromodeling and Simulation via Digital Signal Processing Techniques” framework (known as SIM-DSP framework), which applies digital signal processing techniques to facilitate the SI verification process in the pre-layout design phase. Core identification modules and peripheral (pre-/post-)processing modules have been developed and assembled to form a verification flow. In particular, a single-step discrete cosine transform truncation (DCTT) module has been developed for modeling-simulation process. In DCTT, the response modeling problem is classified as a signal compression problem, wherein the system response can be represented by a truncated set of non-pole based DCT bases, and error can be analyzed through Parseval’s theorem. Practical examples are given to show the applicability of our proposed framework
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