We develop a perturbation theory for strongly continuous semigroups and dual semigroups not based on perturbation of infinitesimal generators but on certain families of bounded linear operators describing the cumulati...
Two kinds of net operations, addition and Cartesian production of P/T nets, are introduced. They are defined on the set of underlying net of P/T systems. The conditions for preserving structural proper- ties of Petri ...
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Two kinds of net operations, addition and Cartesian production of P/T nets, are introduced. They are defined on the set of underlying net of P/T systems. The conditions for preserving structural proper- ties of Petri net after these operations are discussed. It is shown that the set of P/T nets forms an Abelian group for net addition operation and the inverse net of a P/T net in usual meaning of net theo- ry is exactly the inverse of this P/T net as an element of the P/T net group; and that the set of P/T nets forms an Abelian ring for net addition and Cartesian product operations.
We introduce a natural new family of scheduling problems, which allow us to better model data dependencies which occur between program instructions that occur on a synchronous parallel architecture. We look at the pro...
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Higher moment analysis has typically been used to upper bound certain functions. In this paper, we introduce a new combinatorial method to lower bound the expectation of an absolute value by a fourth moment. We presen...
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In this paper, the parallel implementations of two well-known linear state-space filtering algorithms, namely the Kalman and the Lainiotis filters, in MIMD machines are studied from a computational standpoint. The ana...
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In this paper, the parallel implementations of two well-known linear state-space filtering algorithms, namely the Kalman and the Lainiotis filters, in MIMD machines are studied from a computational standpoint. The analysis assumes both time invariant and time varying system models and uses precedence graphs and critical paths. The parallelism efficiency of the implementations is also defined and studied. Results indicate that these algorithms can be implemented in parallel using a comparatively small number of processors. Furthermore, the efficiency of the parallel implementations can be very high or very low, depending on the state and measurement vector dimensions.
Serializability of database transactions is first defined within the framework of linear temporal logic. For commutativity-based serializability, an alternative specification is given in a temporal logic whose semanti...
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Serializability of database transactions is first defined within the framework of linear temporal logic. For commutativity-based serializability, an alternative specification is given in a temporal logic whose semantic interpretation is especially tailored for reasoning about equivalence sequences of histories. The alternative specification method is given in ISTL* and is limited to the specification of concurrency control algorithms based on commutativity. A formal verification system for serializability that uses classical logic reasoning is provided. Within it, proving serializability of transactions executing a concurrency control algorithm is done along the same lines as proving properties of concurrent programs. Serializability for the multiversion-timestamp algorithm is verified.< >
Nonlinear regression is used to fit S-parameter resonance data to a full-circuit model that includes coupling factors and self impedances. This model fits the data better than the simpler Q-circle model that can be de...
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Nonlinear regression is used to fit S-parameter resonance data to a full-circuit model that includes coupling factors and self impedances. This model fits the data better than the simpler Q-circle model that can be derived from the full-circuit model, but a systematic pattern in the residuals persists. This pattern indicates a discrepancy between the full-circuit model and the observed data. By looking at parameter estimates calculated from subsets of the original data, it is demonstrated that the cause of this discrepancy also could introduce significant errors in the model's estimated parameter values.< >
作者：
SKOLNICK, DHSKOLNICK, ADavid H. Skolnickhas practiced naval engineering in both government and industry. He has supported the Military Sealift Command and the Naval Sea Systems Command Ship Design Group and Amphibious Ship Acquisition Program Office
participating in the design and assessment of ship structure evaluation of intact and damaged stability and arrangements during design and construction phases of acquisition conversion and overhaul. He is currently involved in systems engineering and integration. Recent responsibilities have included requirements analyses and feasibility studies interface analyses and computer aided analyses. He received his B.S. in naval architecture and marine engineering from Webb Institute of Naval Architecture in 1982 (as an ASNE scholar) and is currently an M.S. candidate in systems engineering at the University of Virginia. Alfred Skolnickserved over 30 years as an engineering duty officer and retired from the Navy with the rank of captain in 1983. His early assignments included tactical missile engineering
shipboard duty and Polaris submarine inertial navigation. He later served in the Deep Submergence Systems Project was project director
surface effect ships (SES) David Taylor Model Basin director of technology
Joint Navy-Commerce SES Program director
combat systems Naval Sea Systems Command and project manager directed energy weapons. His awards include the Navy League's Parsons Award in 1979 for scientific and technical progress ASNE's Gold Medal in 1981 for high energy laser development the Navy Legion of Merit in 1983 National Capital Engineer of the Year in 1986 and the American Defense Preparedness Association Gold Medal in 1988 for contributions to strategic defense. He was president of ASNE from 1985–1989. He received his B.S. in mathematics from Queens College his M.A. in mathematics from Columbia University his M.S. in electrical engineering from U.S. Naval Postgraduate School and his Ph.D. in electrical engineering/applied mathematics from Polytechnic University. He w
Changing threat requirements and radical budget shifts imply that Navy operational needs will broaden and engineering solutions will face tougher constraints. Existing and emerging technology promise increased combat ...
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Changing threat requirements and radical budget shifts imply that Navy operational needs will broaden and engineering solutions will face tougher constraints. Existing and emerging technology promise increased combat capability in smaller packages;space-based assets will allow operator orchestration of widely dispersed naval units via connectivity attributes previously unavailable. Tactical data relay by downlink may permit reallocation of responsibilities among several platforms, space, air, or seaborne, so ships can be outfitted for custom-use (sensing, unique data processing, high-firepower) and optimized to meet specific mission needs. These evolving capabilities demand a fresh look at ship concepts and prospective force structures consistent with global and fiscal realities. Warfighting performance formerly unknown in small ship design may offer a very effective solution to the intricate, interacting issues of falling defense budgets, diverse operational requirements and complex national priorities. Multimission ships which take advantage of new or current technology to reduce ship size, manning and cost could be affordable in sufficient numbers to meet our continuing worldwide obligations, complement our larger ships' force structure, and produce a balanced fleet. These same ships could satisfy U.S. maritime needs beyond the Navy and improve export trade through foreign military sales (FMS).
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