TY - BOOK TI - Proceedings of the Cornelius Lanczos International Centenary Conference A3 - Chu, Moody T. A3 - Brown, J. A3 - Ellison, D. A3 - Plemmons, R. DA - 1994/// PY - 1994/// SP - 644 PB - SIAM SN - 9780898713398 ER - TY - JOUR TI - Symmetric Toeplitz Matrices with Two Prescribed Eigenpairs AU - Chu, Moody T. AU - Erbrecht, Melissa A. T2 - SIAM Journal on Matrix Analysis and Applications AB - The inverse problem of constructing a real symmetric Toeplitz matrix based on two prescribed eigenpairs is considered. Two new results are obtained. First, it is shown that the dimension of the subspace of Toeplitz matrices with two generically prescribed eigenvectors is independent of the size of the problem, and, in fact, is either two, three, or four, depending upon whether the eigenvectors are symmetric or skew-symmetric and whether n is even or odd. This result is quite notable in that when only one eigenvector is prescribed the dimension is known to be at least $[ ( n + 1 )/2 ]$. Taking into account the prescribed eigenvalues, the authors then show how each unit vector in the null subspace of a certain matrix uniquely determines a Toeplitz matrix that satisfies the prescribed eigenpairs constraint. The cases where two prescribed eigenpairs uniquely determine a Toeplitz matrix are explicitly characterized. DA - 1994/4// PY - 1994/4// DO - 10.1137/s0895479891221757 VL - 15 IS - 2 SP - 623-635 UR - http://dx.doi.org/10.1137/s0895479891221757 ER - TY - CHAP TI - A list of matrix flows with applications T2 - Hamiltonian and Gradient Flows, Algorithms and Control PY - 1994/// UR - https://bookstore.ams.org/fic-3 ER - TY - CONF TI - Parallel solution of Toeplitz and Toeplitz-like linear systems over fields of small positive characteristic AU - Kaltofen, E. AU - Pan, V. A2 - Hong, H. C2 - 1994/// C3 - Proceedings of the First International Symposium of Parallel Symbolic Computation DA - 1994/// SP - 225–233 PB - World Scientific Publishing Co ER - TY - THES TI - The Immersed Interface Method — A Numerical Approach for Partial Differential Equations with Interfaces AU - Li, Zhilin DA - 1994/// PY - 1994/// M3 - PhD thesis PB - University of Washington ER - TY - CONF TI - Formation and development of shear bands in granular material AU - Shearer, Michael AU - Garaizar, F.X. AU - Schaeffer, D.G. AU - Trangenstein, J. C2 - 1994/// C3 - Transactions of the 11th Army Conference on Applied Mathematics and Computing DA - 1994/// SP - 15–28 PB - Army Research Office ER - TY - CONF TI - Computational speedup for general nonlinear higher index DAE integrators AU - Campbell, Stephen L. AU - Zhong, Y. T2 - 14th IMACS World congress on computation and applied mathematics C2 - 1994/// C3 - IMACS '94 : proceedings of the 14th IMACS World congress on computation and applied mathematics CY - Atlanta, Georgia DA - 1994/// PY - 1994/7// SP - 69–73 PB - Georgia Institute of Technology ER - TY - CONF TI - DAE Approximations of PDE Modeled Control Problems AU - Campbell, Stephen L. T2 - 2nd IEEE Mediterranean Symposium on New Directions in Control and Automation C2 - 1994/// C3 - Proceedings of the 2nd IEEE Mediterranean Symposium on New Directions in Control and Automation CY - Crete, Greece DA - 1994/// PY - 1994/6/19/ SP - 407–414 ER - TY - JOUR TI - Numerical Methods for Unstructured Higher Index DAEs AU - Campbell, Stephen L. T2 - Annals of Numerical Mathematics DA - 1994/// PY - 1994/// VL - 1 SP - 265–278 ER - TY - JOUR TI - UNIDIRECTIONAL WAVES ON RINGS - MODELS FOR CHIRAL PREFERENCE OF CIRCUMNUTATING PLANTS AU - Lubkin, S. T2 - Bulletin of Mathematical Biology DA - 1994/// PY - 1994/// DO - 10.1016/s0092-8240(05)80291-5 VL - 56 IS - 5 SP - 795-810 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:A1994PE77000002&KeyUID=WOS:A1994PE77000002 ER - TY - JOUR TI - OSCILLATORY REACTION-DIFFUSION EQUATIONS ON RINGS AU - Lubkin, S. AU - Rand, R. T2 - Journal of Mathematical Biology DA - 1994/// PY - 1994/// DO - 10.1007/bf00573464 VL - 32 IS - 6 SP - 617-632 UR - http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcAuth=ORCID&SrcApp=OrcidOrg&DestLinkType=FullRecord&DestApp=WOS_CPL&KeyUT=WOS:A1994NZ38700008&KeyUID=WOS:A1994NZ38700008 KW - OSCILLATORS KW - BIFURCATIONS KW - REACTION-DIFFUSION EQUATIONS KW - SPATIAL HETEROGENEITY ER - TY - CONF TI - Relative perturbation bounds for eigenspaces and singular vector subspaces AU - Eisenstat, S.C. AU - Ipsen, I.C.F. T2 - Fifth SIAM Conference on Applied Linear Algebra A2 - Lewis, J.G. C2 - 1994/// C3 - Proceedings of the Fifth SIAM Conference on Applied Linear Algebra CY - Snowbird, Utah DA - 1994/// PY - 1994/6/15/ SP - 62–65 PB - SIAM SN - 9780898713367 ER - TY - CHAP TI - On the singular value decomposition of triangular matrices AU - Chandrasekaran, S. AU - Ipsen, I.C.F. T2 - Numerical algebra : proceedings of '92 Shanghai International Numerical Algebra and its Applications Conference A2 - Er-xiong, Jiang PY - 1994/// SP - 85–89 PB - China Science and Technology Press ER - TY - JOUR TI - A divide and conquer algorithm for computing singular values AU - Chandrasekaran, S. AU - Ipsen, I.C.F. T2 - Zeitschrift für Angewandte Mathematik und Mechanik DA - 1994/// PY - 1994/// VL - 74 IS - 6 SP - 532–534 ER - TY - CONF TI - High Pressure Vapour Transport of Binary and Ternary Compound Semiconductors AU - Fiechter, S. AU - Castleberry, R.H. AU - Wood, G. AU - Bachmann, K.J. AU - Tran, H.T. AU - Ito, K. AU - Scroggs, J.S. T2 - 123rd Annual TMS Meeting A2 - Schiffman, R.A. A2 - Andrews, J.B. C2 - 1994/// C3 - 6th International Symposium on Experimental Methods for Microgravity Materials Science : proceedings of the Sixth International Symposium on Experimental Methods for Microgravity Materials Science CY - San Francisco, CA DA - 1994/// PY - 1994/2/28/ SP - 93–100 PB - Minerals, Metals and Materials Society ER - TY - CONF TI - Gasdynamics and Transport in a High-Pressure Reactor Under Microgravity Conditions AU - Banks, H.T. AU - Ito, K. AU - Scroggs, J.S. AU - Tran, H.T. AU - Bachmann, K.J. AU - Castleberry, H. AU - Fiechter, S. T2 - 2nd IEEE Mediterranean Symposium on New Directions in Control and Automation (MED '94) C2 - 1994/// C3 - Proceedings of the 2nd IEEE Mediterranean Symposium on New Directions in Control and Automation (MED '94) CY - Louis Maleme Beach Hotel, Chania, Crete, Greece DA - 1994/// PY - 1994/6/19/ SP - 427–433 PB - IEEE Publications ER - TY - CONF TI - RISC-CLP(CF) Constraint Logic Programming over Complex Functions AU - Hong, Hoon A2 - Pfenning, Frank C2 - 1994/// C3 - Logic Programming and Automated Reasoning, 5th International Conference, LPAR'94, Kiev, Ukraine, July 16-22, 1994, Proceedings DA - 1994/// DO - 10.1007/3-540-58216-9\_32 VL - 822 SP - 99-113 PB - Springer UR - https://doi.org/10.1007/3-540-58216-9\_32 ER - TY - CONF TI - Parallel Computation of Modular Multivariate Polynominal Resultants on a Shared Memory Machine AU - Hong, Hoon AU - Loidl, Hans-Wolfgang A2 - Buchberger, Bruno A2 - Volkert, Jens C2 - 1994/// C3 - Parallel Processing: CONPAR 94 - VAPP VI, Third Joint International Conference on Vector and Parallel Processing, Linz, Austria, September 6-8, 1994, Proceedings DA - 1994/// DO - 10.1007/3-540-58430-7\_29 VL - 854 SP - 325-336 PB - Springer UR - https://doi.org/10.1007/3-540-58430-7\_29 ER - TY - JOUR TI - Safe starting regions by fixed points and tightening AU - Hong, H. AU - Stahl, V. T2 - Computing DA - 1994/9// PY - 1994/9// DO - 10.1007/bf02307383 VL - 53 IS - 3-4 SP - 323-335 UR - http://dx.doi.org/10.1007/bf02307383 KW - NONLINEAR EQUATION SYSTEMS KW - INTERVAL ARITHMETIC KW - SAFE STARTING REGIONS KW - TIGHTENING ER - TY - CONF TI - On a new predictive control strategy: application to a flexible-joint robot AU - von Wissel, D. AU - Nikoukhah, R. AU - Campbell, S.L. T2 - 1994 33rd IEEE Conference on Decision and Control AB - It is shown that it is possible to greatly improve the performance of the predictive control strategy proposed by Jankowski and Van Brussel (1992) by using preliminary linear feedback. This is illustrated using the example of a flexible-joint robot path following problem.< > C2 - 1994/// C3 - Proceedings of 1994 33rd IEEE Conference on Decision and Control DA - 1994/// DO - 10.1109/cdc.1994.411325 PB - IEEE SN - 0780319680 UR - http://dx.doi.org/10.1109/cdc.1994.411325 ER - TY - CONF TI - Numerically generated path stabilizing controllers. I. Theoretical concerns AU - Campbell, S.L. AU - Nikoukhah, R. AU - von Wissel, D. T2 - 1994 American Control Conference - ACC '94 AB - A method for the prescribed path control of robotic arms has previously been proposed which utilizes the ability to numerically integrate higher index DAE models quickly. In this paper the authors examine some of the issues involved with this method in order to effectively apply it to a wider class of path control problems. C2 - 1994/// C3 - Proceedings of 1994 American Control Conference - ACC '94 DA - 1994/// DO - 10.1109/acc.1994.752408 PB - IEEE SN - 0780317831 UR - http://dx.doi.org/10.1109/acc.1994.752408 ER - TY - JOUR TI - Explicit formulae for completions of linear time varying singular systems of differential equations AU - Campbell, Stephen L. AU - Rakowski, Marek T2 - Circuits, Systems, and Signal Processing DA - 1994/6// PY - 1994/6// DO - 10.1007/bf01188105 VL - 13 IS - 2-3 SP - 185-199 J2 - Circuits Systems and Signal Process LA - en OP - SN - 0278-081X 1531-5878 UR - http://dx.doi.org/10.1007/bf01188105 DB - Crossref ER - TY - JOUR TI - The Immersed Interface Method for Elliptic Equations with Discontinuous Coefficients and Singular Sources AU - LeVeque, Randall J. AU - Li, Zhilin T2 - SIAM Journal on Numerical Analysis AB - The authors develop finite difference methods for elliptic equations of the form \[ \nabla \cdot (\beta (x)\nabla u(x)) + \kappa (x)u(x) = f(x)\] in a region $\Omega $ in one or two space dimensions. It is assumed that $\Omega $ is a simple region (e.g., a rectangle) and that a uniform rectangular grid is used. The situation is studied in which there is an irregular surface $\Gamma $ of codimension 1 contained in $\Omega $ across which $\beta ,\kappa $, and f may be discontinuous, and along which the source f may have a delta function singularity. As a result, derivatives of the solution u may be discontinuous across $\Gamma $. The specification of a jump discontinuity in u itself across $\Gamma $ is allowed. It is shown that it is possible to modify the standard centered difference approximation to maintain second order accuracy on the uniform grid even when $\Gamma $ is not aligned with the grid. This approach is also compared with a discrete delta function approach to handling singular sources, as used in Peskin’s immersed boundary method. DA - 1994/8// PY - 1994/8// DO - 10.1137/0731054 VL - 31 IS - 4 SP - 1019-1044 J2 - SIAM J. Numer. Anal. LA - en OP - SN - 0036-1429 1095-7170 UR - http://dx.doi.org/10.1137/0731054 DB - Crossref KW - ELLIPTIC EQUATION KW - FINITE DIFFERENCE METHODS KW - IRREGULAR DOMAIN KW - INTERFACE KW - DISCONTINUOUS COEFFICIENTS KW - SINGULAR SOURCE TERM KW - DELTA FUNCTIONS ER - TY - JOUR TI - Unloading near a shear band in granular material AU - Shearer, Michael AU - Schaeffer, David G. T2 - Quarterly of Applied Mathematics AB - We consider a model for dynamic deformations of granular materials which allows for the localisation of flow and the consequent development of shear bands. We construct solutions, asymptotic in small time, of Riemann initial value problems in one space dimension that include a shear band. An unusual feature of the solutions is that they are not scale invariant DA - 1994/9/1/ PY - 1994/9/1/ DO - 10.1090/qam/1292207 VL - 52 IS - 3 SP - 579-600 J2 - Quart. Appl. Math. LA - en OP - SN - 0033-569X 1552-4485 UR - http://dx.doi.org/10.1090/qam/1292207 DB - Crossref ER - TY - CONF TI - Synthèse ensembliste d’ondelettes AU - Pesquet, J.C. AU - Combettes, P. L. T2 - Actes de la Conférence Temps-Fréquence, Ondelettes et Multirésolution C2 - 1994/3/9/ C3 - Actes de la Conférence Temps-Fréquence, Ondelettes et Multirésolution CY - Lyon, France DA - 1994/3/9/ PY - 1994/3/9/ SP - 14.1–14.10 ER - TY - CONF TI - A fast parallel projection algorithm for set theoretic image recovery AU - Combettes, P.L. AU - Puh, H. T2 - ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing AB - A new projection algorithm for convex set theoretic image recovery [reconstruction and restoration] is presented. This algorithm comprises all serial and parallel projection methods as particular cases and is straightforwardly implementable on concurrent processors. It proceeds by taking convex combinations of selected projections at each iteration and allows extrapolated relaxations far beyond the range [0,2] used in conventional algorithms. These extrapolated, iteration-dependent relaxations result in very fast convergence. Numerical results are provided which show that the proposed algorithm outperforms existing ones, in particular the popular cyclic method of projections onto convex sets [POCS].< > C2 - 1994/4/19/ C3 - Proceedings of ICASSP '94. IEEE International Conference on Acoustics, Speech and Signal Processing CY - Adelaide, Australia DA - 1994/4/19/ PY - 1994/4/19/ DO - 10.1109/icassp.1994.389385 VL - 5 SP - 473–476 PB - IEEE SN - 0780317750 UR - http://dx.doi.org/10.1109/icassp.1994.389385 ER - TY - CONF TI - Selecting Statistical Information In Set Theoretic Signal Processing AU - Combettes, P.L. AU - Chaussalet, T.J. T2 - IEEE Seventh SP Workshop on Statistical Signal and Array Processing C2 - 1994/6/26/ C3 - IEEE Seventh SP Workshop on Statistical Signal and Array Processing CY - Quebec City, Quebec, Canada DA - 1994/6/26/ PY - 1994/6/26/ DO - 10.1109/ssap.1994.572433 SP - 55–58 PB - IEEE UR - http://dx.doi.org/10.1109/ssap.1994.572433 ER - TY - CONF TI - Set Theoretic Signal Processing AU - Combettes, P.L. T2 - IEEE Seventh SP Workshop on Statistical Signal and Array Processing C2 - 1994/6/26/ C3 - IEEE Seventh SP Workshop on Statistical Signal and Array Processing CY - Quebec City, Quebec, Canada DA - 1994/6/26/ PY - 1994/6/26/ DO - 10.1109/ssap.1994.572418 SP - 1–6 PB - IEEE UR - http://dx.doi.org/10.1109/ssap.1994.572418 ER - TY - CONF TI - Convex set theoretic image recovery via chaotic iterations of approximate projections AU - Combettes, P.L. T2 - 1st International Conference on Image Processing AB - Solving a convex set theoretic image recovery problem amounts to finding a point in the intersection of closed and convex sets in a Hilbert space. Methods employing projections onto the individual sets to build a sequence converging to a point in their intersection have proven most useful to obtain set theoretic solutions. They are nonetheless sometimes difficult to implement because of the theoretical or numerical tedium associated with the computation of projections at each iteration. We propose a general parallel iterative method which processes chaotically approximate projections instead of exact ones. Weak and strong convergence results are presented and subgradient projection methods are discussed as a particular case. > C2 - 1994/11/13/ C3 - Proceedings of 1st International Conference on Image Processing CY - Austin, Texas DA - 1994/11/13/ PY - 1994/11/13/ DO - 10.1109/icip.1994.413863 VL - 3 SP - 182–186 PB - IEEE Comput. Soc. Press SN - 0818669527 UR - http://dx.doi.org/10.1109/icip.1994.413863 ER - TY - JOUR TI - Utilization of automatic differentiation in control algorithms AU - Campbell, S.L. AU - Moore, E. AU - Zhong, Yangchun T2 - IEEE Transactions on Automatic Control AB - Symbolic languages are increasingly being used in the analysis and implementation of control algorithms. Many of these control procedures involve some type of differentiation or Jacobian formulation. Automatic differentiation provides an alternative means of computing this information which is rarely considered in the control literature. This correspondence discusses the use of automatic differentiation. Numerical results comparing the use of automatic differentiation and symbolic approaches in the context of a particular nonlinear control system are given.< > DA - 1994/5// PY - 1994/5// DO - 10.1109/9.284891 VL - 39 IS - 5 SP - 1047-1052 J2 - IEEE Trans. Automat. Contr. OP - SN - 0018-9286 UR - http://dx.doi.org/10.1109/9.284891 DB - Crossref ER - TY - JOUR TI - Progress on a general numerical method for nonlinear higher index DAEs II AU - Campbell, Stephen L. AU - Moore, Edward T2 - Circuits, Systems, and Signal Processing DA - 1994/6// PY - 1994/6// DO - 10.1007/bf01188101 VL - 13 IS - 2-3 SP - 123-138 J2 - Circuits Systems and Signal Process LA - en OP - SN - 0278-081X 1531-5878 UR - http://dx.doi.org/10.1007/bf01188101 DB - Crossref ER - TY - CHAP TI - A Distributed Approach to Problem Solving in Maple AU - Chan, K. C. AU - Díaz, A. AU - Kaltofen, E. T2 - Maple V: Mathematics and its Applications AB - A system is described whereby a Maple computation can be distributed across a network of computers running Unix. The distribution is based on the DSC system, which can ship source code and input data to carefully selected computers for execution and which can retrieve the produced output data. Our code is fully portable and requires no changes of the underlying Maple or Unix systems. Speedup over Maple’ s built-in sequential procedure is demonstrated when computing determinants of integer matrices. PY - 1994/// DO - 10.1007/978-1-4612-0263-9_2 SP - 13-21 OP - PB - Birkhäuser Boston SN - 9780817637910 9781461202639 UR - http://dx.doi.org/10.1007/978-1-4612-0263-9_2 DB - Crossref ER - TY - CONF TI - Factoring high-degree polynomials by the black box Berlekamp algorithm AU - Kaltofen, Erich AU - Lobo, Austin T2 - the international symposium AB - Article Free Access Share on Factoring high-degree polynomials by the black box Berlekamp algorithm Authors: Erich Kaltofen Department of Computer Science, Rensselaer Polytechnic Institute, Troy, New York Department of Computer Science, Rensselaer Polytechnic Institute, Troy, New YorkView Profile , Austin Lobo Department of Computer Science, Rensselaer Polytechnic Institute, Troy, New York Department of Computer Science, Rensselaer Polytechnic Institute, Troy, New YorkView Profile Authors Info & Claims ISSAC '94: Proceedings of the international symposium on Symbolic and algebraic computationAugust 1994 Pages 90–98https://doi.org/10.1145/190347.190371Published:01 August 1994Publication History 14citation740DownloadsMetricsTotal Citations14Total Downloads740Last 12 Months22Last 6 weeks3 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF C2 - 1994/// C3 - Proceedings of the international symposium on Symbolic and algebraic computation - ISSAC '94 DA - 1994/// DO - 10.1145/190347.190371 PB - ACM Press SN - 0897916387 UR - http://dx.doi.org/10.1145/190347.190371 DB - Crossref ER - TY - CONF TI - Asymptotically fast solution of Toeplitz-like singular linear systems AU - Kaltofen, Erich T2 - the international symposium AB - Article Free Access Share on Asymptotically fast solution of Toeplitz-like singular linear systems Author: Erich Kaltofen Department of Computer Science, Rensselaer Polytechnic Institute, Troy, New York Department of Computer Science, Rensselaer Polytechnic Institute, Troy, New YorkView Profile Authors Info & Claims ISSAC '94: Proceedings of the international symposium on Symbolic and algebraic computationAugust 1994 Pages 297–304https://doi.org/10.1145/190347.190431Online:01 August 1994Publication History 15citation299DownloadsMetricsTotal Citations15Total Downloads299Last 12 Months8Last 6 weeks1 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my Alerts New Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF C2 - 1994/// C3 - Proceedings of the international symposium on Symbolic and algebraic computation - ISSAC '94 DA - 1994/// DO - 10.1145/190347.190431 PB - ACM Press SN - 0897916387 UR - http://dx.doi.org/10.1145/190347.190431 DB - Crossref ER - TY - JOUR TI - The spectral radii and norms of large dimensional non-central random matrices AU - Silverstein, Jack W. T2 - Communications in Statistics. Stochastic Models AB - Consider a matrix made up of i.i.d. random variables with positive mean and finite fourth moment. Results are given on its spectral norm and (if it is square) spectral radius as the dimension increases DA - 1994/1// PY - 1994/1// DO - 10.1080/15326349408807308 VL - 10 IS - 3 SP - 525–532 SN - 0882-0287 UR - http://dx.doi.org/10.1080/15326349408807308 ER - TY - JOUR TI - Linear filters and nonlinear forecasting AU - Lloyd, A.L. AU - Gravenor, M.B. T2 - Proceedings of the Royal Society of London. Series B: Biological Sciences AB - We consider the consequences of using linear filters to reduce noise before analysing short time series for low-dimensional chaotic behaviour. We discuss mathematical theory which suggests that certain filters should not affect the results of particular nonlinear analyses. We note that these results have only been proved for purely deterministic systems and need not be true when a stochastic component is present in the time series. In particular, we demonstrate that simple moving average filters can falsely suggest that a white noise data set is chaotic by using a test commonly used by biologists. This incorrect result is not obtained if the method of surrogate data is used together with this test. The results demonstrate the extreme care needed when analysing small data sets by using sophisticated mathematical techniques. The graphical technique we describe may also aid testing for linearity in time series. DA - 1994/5/23/ PY - 1994/5/23/ DO - 10.1098/rspb.1994.0064 VL - 256 IS - 1346 SP - 157-161 SN - 1471-2954 UR - http://dx.doi.org/10.1098/rspb.1994.0064 ER - TY - JOUR TI - Chaos and forecasting AU - Lloyd, Alun L. T2 - Trends in Ecology & Evolution DA - 1994/// PY - 1994/// DO - http://dx.doi.org/10.1016/0169-5347(94)90288-7 VL - 9 IS - 7 SP - 244–245 ER - TY - JOUR TI - Numerical Approximations for Hereditary Systems with Input and Output Delays: Convergence Results and Convergence Rates AU - Manitius, A. AU - Tran, H. T. T2 - SIAM Journal on Control and Optimization AB - In this paper, the averaging approximation scheme for linear retarded functional differential equations with delays in control and observation is considered in the context of the state space theory developed by Pritchard and Salamon [SIAM J. Control Optim., 25 (1987), pp. 121–144]. Using known results from linear semigroup theory, convergence and estimate of convergence rate of the approximating semigroups are established. These extend results due to Banks and Burns [SIAM J. Control Optim., 16 (1978), pp. 169–208] and Lasiecka and Manitius [SIAM J. Numer. Anal., 25 (1988), pp. 883–907] on hereditary systems with delays in state, to the case when delays in control and observation are included. The main difference from the case when delays in input and output are excluded is that unbounded input and output operators must be dealt with in the abstract formulation. Moreover, in the presence of the unboundedness of the input and output operators, new convergence results of the state solutions and the output are also obtained. DA - 1994/9// PY - 1994/9// DO - 10.1137/s0363012989161699 VL - 32 IS - 5 SP - 1332-1363 J2 - SIAM J. Control Optim. LA - en OP - SN - 0363-0129 1095-7138 UR - http://dx.doi.org/10.1137/s0363012989161699 DB - Crossref KW - FUNCTIONAL DIFFERENTIAL EQUATIONS KW - UNBOUNDED INPUT AND OUTPUT OPERATORS KW - AVERAGING APPROXIMATION KW - CONVERGENCE KW - CONVERGENCE RATE ER - TY - CONF TI - A Coordinate Free Approach for Constraint Preserving Higher Index DAE Integrators AU - Campbell, Stephen L. AU - Moore, E. C2 - 1994/// C3 - Proc. 94 IMACS World Congress on Scientific Computation DA - 1994/// SP - 65–68 ER - TY - JOUR TI - Iterations of parallel convex projections in hilbert spaces AU - Combettes, Patrick L. AU - Puh, Hong T2 - Numerical Functional Analysis and Optimization AB - The problem of finding a common point of closed and convex sets in a Hilbert space is considered. A general iterative method of parallel projections is presented, in which the current iterate is projected simultaneously onto selected sets and the new iterate is a relaxed convex combination of the projections. Weak and strong convergence results are established and the influence of the relaxation coefficients is discussed. Convergence to a least-squares solution when the sets do not intersect is also proved. DA - 1994/1// PY - 1994/1// DO - 10.1080/01630569408816563 VL - 15 IS - 3-4 SP - 225-243 J2 - Numerical Functional Analysis and Optimization LA - en OP - SN - 0163-0563 1532-2467 UR - http://dx.doi.org/10.1080/01630569408816563 DB - Crossref ER - TY - JOUR TI - Inconsistent signal feasibility problems: least-squares solutions in a product space AU - Combettes, P.L. T2 - IEEE Transactions on Signal Processing AB - Presents parallel projection methods to find least-squares solutions to inconsistent convex set theoretic signal synthesis problems. The problem of finding a signal that minimizes a weighted average of the squares of the distances to constraint sets is reformulated in a product space, where it is equivalent to that of finding a point that lies in a particular subspace and at minimum distance from the Cartesian product of the original sets. A solution is obtained in the product space via methods of alternating projections which naturally lead to methods of parallel projections in the original space. The convergence properties of the proposed methods are analyzed and signal synthesis applications are demonstrated.< > DA - 1994/// PY - 1994/// DO - 10.1109/78.330356 VL - 42 IS - 11 SP - 2955-2966 J2 - IEEE Trans. Signal Process. OP - SN - 1053-587X UR - http://dx.doi.org/10.1109/78.330356 DB - Crossref ER - TY - CONF TI - Preconditioning Via Asymptotically-defined Domain Decomposition AU - Ashby, S F AU - Kelley, C T AU - Saylor, P E AU - Scroggs, J S A2 - Keyes, D A2 - Xu, J C2 - 1994/// C3 - Proceedings of the Seventh International Conference on Domain Decomposition Methods in Science and Engineering CY - Providence DA - 1994/// VL - 180 SP - 139-150 PB - AMS ER - TY - CONF TI - Identification of the Support of Nonsmoothness AU - Kelley, C T A2 - Hager, W W A2 - Hearn, D W A2 - Pardalos, P M C2 - 1994/// C3 - Large Scale Optimization: State of the Art CY - Boston DA - 1994/// SP - 192-205 PB - Kluwer Academic Publishers B.V. ER - TY - CONF TI - A comparison of strongly convergent solution schemes for sharp front infiltration problems AU - Miller, C T AU - Kelley, C T A2 - Peters, A A2 - Wittum, G A2 - Herrling, B A2 - Meissner, U A2 - Brebbia, C A A2 - Gray, W G A2 - Pinder, G F C2 - 1994/// C3 - Computational Methods in Water Resources X, Vol. 1 DA - 1994/// SP - 325-332 PB - Kluwer Academic Publishers ER - TY - JOUR TI - Chaos and forecasting AU - Lloyd, Alun L. T2 - Trends in Ecology & Evolution DA - 1994/7// PY - 1994/7// DO - 10.1016/0169-5347(94)90288-7 VL - 9 IS - 7 SP - 244-245 J2 - Trends in Ecology & Evolution LA - en OP - SN - 0169-5347 UR - http://dx.doi.org/10.1016/0169-5347(94)90288-7 DB - Crossref ER - TY - JOUR TI - Hypothesis: a controlled chaotic attractor constitutes the central oscillator of the circadian clock AU - Lloyd, David AU - Lloyd, Alun L. T2 - Biochemical Society Transactions AB - Conference Article| August 01 1994 Hypothesis: a controlled chaotic attractor constitutes the central oscillator of the circadian clock DAVID LLOYD; DAVID LLOYD *Microbiology Group (PABIO), University of Wales College of Cardiff, P.O. Box 915, Cardiff CF1 3TL, Wales, UK Search for other works by this author on: This Site PubMed Google Scholar ALUN L. LLOYD ALUN L. LLOYD #Department of Zoology, University of Oxford, South Parks Road, Oxford OX1 3PS, UK Search for other works by this author on: This Site PubMed Google Scholar Author and article information Publisher: Portland Press Ltd Online ISSN: 1470-8752 Print ISSN: 0300-5127 © 1994 Biochemical Society1994 Biochem Soc Trans (1994) 22 (3): 322S. https://doi.org/10.1042/bst022322s Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Facebook Twitter LinkedIn Email Cite Icon Cite Get Permissions Citation DAVID LLOYD, ALUN L. LLOYD; Hypothesis: a controlled chaotic attractor constitutes the central oscillator of the circadian clock. Biochem Soc Trans 1 August 1994; 22 (3): 322S. doi: https://doi.org/10.1042/bst022322s Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsBiochemical Society Transactions Search Advanced Search This content is only available as a PDF. © 1994 Biochemical Society1994 Article PDF first page preview Close Modal You do not currently have access to this content. DA - 1994/8// PY - 1994/8// DO - 10.1042/bst022322s VL - 22 IS - 3 SP - 322S-322S J2 - Biochm. Soc. Trans. LA - en OP - SN - 0300-5127 1470-8752 UR - http://dx.doi.org/10.1042/bst022322s DB - Crossref ER - TY - JOUR TI - Multilevel Algorithms for Constrained Compact Fixed Point Problems AU - Kelley, C. T. AU - Sachs, E. W. T2 - SIAM Journal on Scientific Computing AB - In this paper the authors extend the multilevel algorithm of Atkinson and Brakhage for compact fixed point problems and the projected Newton method of Bertsekas to create a fast multilevel algorithm for parabolic boundary control problems having bound constraints on the control. Results are extended from finite dimension on constraint identification. This approach permits both adaptive integration in time and inexact evaluation of the cost functional. DA - 1994/5// PY - 1994/5// DO - 10.1137/0915042 VL - 15 IS - 3 SP - 645-667 J2 - SIAM J. Sci. Comput. LA - en OP - SN - 1064-8275 1095-7197 UR - http://dx.doi.org/10.1137/0915042 DB - Crossref KW - PROJECTED NEWTON METHOD KW - CONSTRAINT IDENTIFICATION KW - COLLECTIVE COMPACTNESS KW - PARABOLIC OPTIMAL CONTROL PROBLEMS ER - TY - JOUR TI - Uniform Stability of Markov Chains AU - Ipsen, Ilse C. F. AU - Meyer, Carl D. T2 - SIAM Journal on Matrix Analysis and Applications AB - By deriving a new set of tight perturbation bounds, it is shown that all stationary probabilities of a finite irreducible Markov chain react essentially in the same way to perturbations in the transition probabilities. In particular, if at least one stationary probability is insensitive in a relative sense, then all stationary probabilities must be insensitive in an absolute sense. New measures of sensitivity are related to more traditional ones, and it is shown that all relevant condition numbers for the Markov chain problem are small multiples of each other. Finally, the implications of these findings to the computation of stationary probabilities by direct methods are discussed, and the results are applied to stability issues in nearly transient chains. DA - 1994/10// PY - 1994/10// DO - 10.1137/s0895479892237562 VL - 15 IS - 4 SP - 1061-1074 J2 - SIAM J. Matrix Anal. & Appl. LA - en OP - SN - 0895-4798 1095-7162 UR - http://dx.doi.org/10.1137/s0895479892237562 DB - Crossref KW - MARKOV CHAINS KW - STATIONARY DISTRIBUTION KW - STOCHASTIC MATRIX KW - SENSITIVITY ANALYSIS KW - PERTURBATION THEORY KW - STABILITY OF A MARKOV CHAIN KW - CONDITION NUMBERS ER - TY - JOUR TI - Backward errors for eigenvalue and singular value decompositions AU - Chandrasekaran, S. AU - Ipsen, I.C.F. T2 - Numerische Mathematik DA - 1994/7/1/ PY - 1994/7/1/ DO - 10.1007/s002110050057 VL - 68 IS - 2 SP - 215-223 J2 - Numerische Mathematik OP - SN - 0029-599X 0945-3245 UR - http://dx.doi.org/10.1007/s002110050057 DB - Crossref ER - TY - JOUR TI - On Rank-Revealing Factorisations AU - Chandrasekaran, Shivkumar AU - Ipsen, Ilse C. F. T2 - SIAM Journal on Matrix Analysis and Applications AB - The problem of finding a rank-revealing QR (RRQR) factorisation of a matrix A consists of permuting the columns of A such that the resulting QR factorisation contains an upper triangular matrix whose linearly dependent columns are separated from the linearly independent ones. In this paper a systematic treatment of algorithms for determining RRQR factorisations is presented. In particular, the authors start by presenting precise mathematical formulations for the problem of determining a RRQR factorisation, all of them optimisation problems. Then a hierarchy of “greedy” algorithms is derived to solve these optimisation problems, and it is shown that the existing RRQR algorithms correspond to particular greedy algorithms in this hierarchy. Matrices on which the greedy algorithms, and therefore the existing RRQR algorithms, can fail arbitrarily badly are presented. Finally, motivated by an insight from the behaviour of the greedy algorithms, the authors present “hybrid” algorithms that solve the optimisation problems almost exactly (up to a factor proportional to the size of the matrix). Applying the hybrid algorithms as a follow-up to the conventional greedy algorithms may prove to be useful in practice. DA - 1994/4// PY - 1994/4// DO - 10.1137/s0895479891223781 VL - 15 IS - 2 SP - 592-622 J2 - SIAM J. Matrix Anal. & Appl. LA - en OP - SN - 0895-4798 1095-7162 UR - http://dx.doi.org/10.1137/s0895479891223781 DB - Crossref KW - CONDITION ESTIMATION KW - PIVOTING KW - ORTHOGONAL FACTORIZATION KW - NUMERICAL RANK KW - SINGULAR VALUES ER - TY - JOUR TI - Modeling and Control of Acoustic Structure Interaction Problems Via Piezoceramic Actuators: 2-D Numerical Examples AU - Banks, H. T. AU - Silcox, R. J. AU - Smith, R. C. T2 - Journal of Vibration and Acoustics AB - The modeling and active control of acoustic pressure in a 2-D cavity with a flexible boundary (a beam) is considered. Control is implemented in the model via piezoceramic patches on the beam, which are excited in a manner so as to produce pure bending moments. Approximation techniques are discussed and, by writing the resulting system as an abstract Cauchy equation, the problem of reducing interior pressure fluctuations can be posed in the context of an LQR time domain state space formulation. Examples illustrating the dynamic behavior of the coupled system, as well as demonstrating the viability of the control method on a variety of problems with periodic forcing functions, are presented. DA - 1994/// PY - 1994/// DO - 10.1115/1.2930440 VL - 116 IS - 3 SP - 386 J2 - J. Vib. Acoust. LA - en OP - SN - 0739-3717 UR - http://dx.doi.org/10.1115/1.2930440 DB - Crossref ER - TY - JOUR TI - Feedback control of noise in a 2-D nonlinear structural acoustics model AU - Smith, R.C. AU - Banks, H.T. T2 - Discrete and Continuous Dynamical Systems AB - A time domain feedback control methodology for reducing sound pressure levels in a nonlinear 2-D structural acoustics application is presented. The interior noise in this problem is generated through vibrations of one wall of the cavity (in this case a beam), and control is implemented through the excitation of piezoceramic patches which are bonded to the beam. These patches are mounted in pairs and are wired so as to create pure bending moments which directly affect the manner in which the structure vibrates. Th application of control in this manner leads to an unbounded control input term and the implications of this are discussed. The coupling between the beam vibrations and the interior acoustic response is inherently nonlinear, and this is addressed when developing a control scheme for the problem. Gains for the problem are calculated using a periodic LQR theory and are then fed back into the nonlinear system with results being demonstrated by a set of numerical examples. In particular, these examples demonstrate the viability of the method in cases involving excitation involving a large number of frequencies through both spatially uniform and nonuniform exterior forces. DA - 1994/10// PY - 1994/10// DO - 10.3934/dcds.1995.1.119 VL - 1 IS - 1 SP - 119-149 J2 - DCDS-A LA - en OP - SN - 1078-0947 UR - http://dx.doi.org/10.3934/dcds.1995.1.119 DB - Crossref ER - TY - JOUR TI - FRACTAL APPROACH TO LIGHTNING RADIATION ON A TORTUOUS CHANNEL AU - VECCHI, G AU - LABATE, D AU - CANAVERO, F T2 - RADIO SCIENCE AB - In this paper the radiation from a geometrically fractal (i.e., arbitrarily irregular) discharge channel is investigated from the point of view of engineering applications of fractal geometry. Numerical results are presented for lightning return stroke radiation, which demonstrate that the time waveform of radiated field (in the Fraunhofer region) is a fractal, and within the framework of employed approximations, it has the same fractal dimension as the channel path. Some implications of this finding are discussed along with the limitations of the model. DA - 1994/// PY - 1994/// DO - 10.1029/93RS03030 VL - 29 IS - 4 SP - 691-704 SN - 0048-6604 ER - TY - PCOMM TI - A COMPARISON OF FRACTAL DIMENSION AND SPECTRUM COEFFICIENT CHARACTERIZATION OF 1/F-ALPHA NOISE AU - LABATE, D AU - CANAVERO, F AU - DEMARCHI, A DA - 1994/4// PY - 1994/4// DO - 10.1088/0026-1394/31/1/011 SP - 51-53 ER - TY - JOUR TI - NUMERICAL-ANALYSIS OF A NONCONVEX VARIATIONAL PROBLEM RELATED TO SOLID-SOLID PHASE-TRANSITIONS AU - GREMAUD, PA T2 - SIAM JOURNAL ON NUMERICAL ANALYSIS AB - The description of equilibria of shape memory alloys or other ordered materials gives rise to nonconvex variational problems. In this paper, a two-dimensional model of such materials is studied. Due to the fact that the corresponding functional has two symmetry-related (martensitic) energy wells, the numerical approximation of the deformation gradient does not converge, but tends to oscillate between the two wells, as the size of the mesh is refined. These oscillations may be interpreted in terms of microstructures. Using a nonconforming $\mathcal{P}_1 $ finite element, an estimate is given for the rate of convergence of the probability for the approximated deformation to have its gradient “near” one of the two (martensitic) wells. DA - 1994/2// PY - 1994/2// DO - 10.1137/0731006 VL - 31 IS - 1 SP - 111-127 SN - 0036-1429 KW - FINITE ELEMENT METHOD KW - RATE OF CONVERGENCE KW - NUMERICAL APPROXIMATION KW - NONCONVEX KW - VARIATIONAL PROBLEM ER - TY - CONF TI - Exact SPICE model of field coupling to multiconductor transmission lines AU - Dilece, B. AU - Isnardi, L. AU - Labate, D. AU - Canavero, F. G. C2 - 1994/// C3 - 1994 International Symposium on Electromagnetic Compatibility, Hotel Sendai Plaza, Sendai, Japan, May 16-20, 1994 DA - 1994/// SP - 12-15 PB - Tokyo: Institute of Electronics, Information and Communication Engineers; Institute of Electrical Engineers of Japan SN - 078032000X ER -