A ship design methodology is presented for developing hull forms that attain improved performance in both seakeeping and resistance. Contrary to traditional practice, the methodology starts with developing a seakeepin...
A ship design methodology is presented for developing hull forms that attain improved performance in both seakeeping and resistance. Contrary to traditional practice, the methodology starts with developing a seakeeping-optimized hull form without making concessions to other performance considerations, such as resistance. The seakeeping-optimized hull is then modified to improve other performance characteristics without degrading the seakeeping. Presented is a point-design example produced by this methodology. Merits of the methodology and the point design are assessed on the basis of theoretical calculations and model experiments. This methodology is an integral part of the Hull Form Design System (HFDS) being developed for computer-supported naval ship design. The modularized character of HFDS and its application to hull form development are discussed.
In this paper the weighted quadratic sum of (formula presented) stable linear discrete system xk+1 = Axk is discussed. The formula of J is obtained from matrix z-transform formulation. Alternatively, it is shown that ...
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作者：
BECKER, LOUIS A.SIEGRIST, FRANKLIN I.Louis A. Becker was born in New Rochelle
N.Y. in 1930 receiving his earlier education in the New Rochelle Public Schools. He completed his undergraduate studies at Manhattan College in 1952 receiving his BCE degree during which time he was also engaged in land surveying. Following this he did postgraduate study at Virginia Polytechnic Institute obtaining his MS in 1954. He joined Naval Ship Research and Development Center in 1953 as a Junior Engineer and is currently the Head of the Engineering & Facilities Division Structures Department. His field of specialization is Structural Research and Development. Franklin I. Siegrist was born in Knoxville
Tenn. in 1937 receiving his earlier education in the Public Schools of Erie Pa. He attended Pennsylvania State University graduating in 1962 with a Bachelor of Science degree in Electrical Engineering having prior to that time served four years in the U. S. Navy. He was a Junior Engineer in the AC Spark Plug Division of General Motors from 1962 until 1964 at which time he came to the David Taylor Model Basin as an Electrical Engineer in the Industrial Department. He is currently Supervisory Engineer for Electrical and Electronics Engineering Structures Department Naval Ship Research and Development Center. His field of specialization is Electrical Engineering Control Systems Data Collection Systems Computer Applications to Structural Research and Hydraulic System Design. In the last of these he holds Patent Rights on a “Hydraulic Supercharge and Cooling Circuit” granted in 1970.
Sufficient conditions for the asymptotic stability in the large of pulse-modulated feedback systems are developed from the operator theoretic viewpoint. Stability here requires that the pulse-modulated feedback system...
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Sufficient conditions for the asymptotic stability in the large of pulse-modulated feedback systems are developed from the operator theoretic viewpoint. Stability here requires that the pulse-modulated feedback system be a Lipschitz continuous operator on the extended space L_{1e} . This strong definition of stability is motivated by an examination of a first-order pulsewidth-modulated system. To provide a unified format for the main development two distinct general classes of pulse modulators are defined. Type I includes the pulsewidth modulator and more general pulsewidth frequency modulators that contain a sampler. Type II includes, for example, the integral pulse frequency modulator and its generalizations. For elements of Type I conditions are derived to bound the incremental gain (on L_{1e} ) of the modulator in cascade with a linear element; a standard transformation of the feedback loop similar to that used in the derivation of the Popov criterion yields sufficient conditions for stability of the feedback system in the above strong sense. Type II modulators are discontinuous on any normed linear space and thus, only conditions for boundedness of the closed-loop system as an operator on L 1 are given for this case.
This paper considers the design of linear time-varying networks and of nonlinear time-invariant networks, the latter being operated in the small-signal mode. In the first part, the design example considered is a netwo...
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This paper considers the design of linear time-varying networks and of nonlinear time-invariant networks, the latter being operated in the small-signal mode. In the first part, the design example considered is a network whose time delay is a prescribed function of time. A quadratic performance criterion 'is formulated and the design is obtained iteratively by steepest descent. The second part of the paper considers the design of a nonlinear timeinvariant network with variable bias sources whose small-signal equivalent network is identical with a given linear time-varying network. Explicit conditions are given under which this can be done.
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