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Full-Text Articles in Physical Sciences and Mathematics

Universal Wormhole Routing, Ronald I. Greenberg, Hyeong-Cheol Oh Dec 1993

Universal Wormhole Routing, Ronald I. Greenberg, Hyeong-Cheol Oh

Computer Science: Faculty Publications and Other Works

We examine the wormhole routing problem in terms of the "congestion" c and "dilation" d for a set of packet paths. We show, with mild restrictions, that there is a simple randomized algorithm for routing any set of P packets in O(cdη + cLηlog P) time, where L is the number of flits in a packet, and η = min {d,L]; only a constant number of flits are stored in each queue at any time. Using this result, we show that a fat-tree network of area Θ(A) can simulate wormhole routing on any network of comparable area with O(log 3 …


Parallel Algorithms For Single-Layer Channel Routing, Ronald I. Greenberg, Shih-Chuan Hung, Jau-Der Shih Dec 1993

Parallel Algorithms For Single-Layer Channel Routing, Ronald I. Greenberg, Shih-Chuan Hung, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

We provide efficient parallel algorithms for the minimum separation, offset range, and optimal offset problems for single-layer channel routing. We consider all the variations of these problems that have linear-time sequential solutions rather than limiting attention to the ``river-routing'' context, where single-sided connections are disallowed. For the minimum separation problem, we obtain O(lgN) time on a CREW PRAM or O(lgN/lglgN) time on a CRCW PRAM, both with optimal work (processor-time product) of O(N), where N is the number of terminals. For the offset range problem, we obtain the same time and processor bounds as long as only one side of …


New Exactly Solvable Hamiltonians - Shape Invariance And Self-Similarity, David T. Barclay, Ranabir Dutt, Asim Gangopadhyaya, Avinash Khare, A. Pagnamenta, Uday P. Sukhatne Oct 1993

New Exactly Solvable Hamiltonians - Shape Invariance And Self-Similarity, David T. Barclay, Ranabir Dutt, Asim Gangopadhyaya, Avinash Khare, A. Pagnamenta, Uday P. Sukhatne

Physics: Faculty Publications and Other Works

We discuss in some detail the self-similar potentials of Shabat and Spiridonov which are reflectionless and have an infinite number of bound states. We demonstrate that these self-similar potentials are in fact shape invariant potentials within the formalism of supersymmetric quantum mechanics. In particular, using a scaling ansatz for the change of parameters, we obtain a large class of new, reflectionless, shape invariant potentials of which the Shabat-Spiridonov ones are a special case. These new potentials can be viewed as q-deformations of the single soliton solution corresponding to the Rosen-Morse potential. Explicit expressions for the energy eigenvalues, eigenfunctions and transmission …


Semiclassical Approach To Quantum-Mechanical Problems With Broken Supersymmetry, Ranabir Dutt, Asim Gangopadhyaya, Avinash Khare, A. Pagnamenta, Uday P. Sukhatne Sep 1993

Semiclassical Approach To Quantum-Mechanical Problems With Broken Supersymmetry, Ranabir Dutt, Asim Gangopadhyaya, Avinash Khare, A. Pagnamenta, Uday P. Sukhatne

Physics: Faculty Publications and Other Works

The semiclassical WKB approximation method is reexamined in the context of nonrelativistic quantum-mechanical bound-state problems with broken supersymmetry (SUSY). This gives rise to an alternative quantization condition (denoted by BSWKB) which is different from the standard WKB formula and also different from the previously studied supersymmetric (SWKB) formula for unbroken SUSY. It is shown that to leading order in ħ, the BSWKB condition yields exact energy eigenvalues for shape-invariant potentials with broken SUSY (harmonic oscillator, Pöschl-Teller I and II) which are known to be analytically solvable. Further, we show explicitly that the higher-order corrections to these energy eigenvalues, up to …


Synthesis Of N-Boc-3-Azabicyclo[3.3.0]Octan-7-One Via Reductive Pauson-Khand Cyclization And Subsequent Conversion To A Novel Diazatricyclic Ring System, Daniel Becker, Daniel L. Flynn Jun 1993

Synthesis Of N-Boc-3-Azabicyclo[3.3.0]Octan-7-One Via Reductive Pauson-Khand Cyclization And Subsequent Conversion To A Novel Diazatricyclic Ring System, Daniel Becker, Daniel L. Flynn

Chemistry: Faculty Publications and Other Works

An intramolecular reductive Pauson-Khand reaction of the hexacarbonyldicobalt complex of N-(tert-butyloxycarbonyl)allylpropargylamine under dry-state adsorption conditions directly afforded the saturated N-BOC-3-azabicyclo[3.3.0]octan-7-one when the reaction was performed under an inert atmosphere. This bicyclic ketone was converted in several steps to the novel octahydro-1-azeto[2′,3′:3,4]cyclopenta[1,2-C]pyrrole ring system as confirmed by single crystal X-ray analysis.


Feasible Offset And Optimal Offset For Single-Layer Channel Routing, Ronald I. Greenberg, Jau-Der Shih Jun 1993

Feasible Offset And Optimal Offset For Single-Layer Channel Routing, Ronald I. Greenberg, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

The paper provides an efficient method to find all feasible offsets for a given separation in a VLSI channel routing problem in one layer. The prior literature considers this task only for problems with no single-sided nets. When single-sided nets are included, the worst-case solution time increases from Theta(n) to Omega(n^2), where n is the number of nets. But, if the number of columns c is O(n), one can solve the problem in time O(n^{1.5}lg n ), which improves upon a `naive' O(cn) approach. As a corollary of this result, the same time bound suffices to find the optimal offset …


Supersymmetry And The Tunneling Problem In An Asymmetric Double Well, Asim Gangopadhyaya, Prasanta K. Panigrahi, Uday P. Sukhatne Apr 1993

Supersymmetry And The Tunneling Problem In An Asymmetric Double Well, Asim Gangopadhyaya, Prasanta K. Panigrahi, Uday P. Sukhatne

Physics: Faculty Publications and Other Works

The techniques of supersymmetric quantum mechanics are applied to the calculation of the energy difference between the ground state and the first excited state of an asymmetric double well. This splitting, originating from the tunneling effect, is computed via a systematic, rapidly converging perturbation expansion. Perturbative calculations to any order can be easily carried out using a logarithmic perturbation theory. Our approach yield substantially better results than alternative widely used semiclassical analyses.


A Systolic Simulation And Transformation System, Ronald I. Greenberg, H.-C. Oh Mar 1993

A Systolic Simulation And Transformation System, Ronald I. Greenberg, H.-C. Oh

Computer Science: Faculty Publications and Other Works

This paper presents a CAD tool, SystSim, to ease the design of systolic systems. Given a high-level, functional description of processors, and a high-level description of their interconnection, SystSim will perform simulations and provide graphical output. SystSim will also perform transformations such as retiming, which eases use of the methodology of Leiserson and Saxe of designing a system with broadcasting and then obtaining a systolic system through retiming.


Studies Of The Solid-Phase Pauson-Khand Reaction Selective In-Situ Enone Reduction To 3-Azabicyclo[3.3.0]Oct-Anones, Daniel Becker, Daniel L. Flynn Mar 1993

Studies Of The Solid-Phase Pauson-Khand Reaction Selective In-Situ Enone Reduction To 3-Azabicyclo[3.3.0]Oct-Anones, Daniel Becker, Daniel L. Flynn

Chemistry: Faculty Publications and Other Works

The Smit-Caple DSAC Pauson-Khand cyclization of a series of N-protected allyl propargyl amines in the absence of oxygen gave rise to formation of the saturated azabicyclo[3.3.0]octanones in excellent yields. Standard cyclization in air gave mixtures of saturated and unsaturated ketones.


Isolation Of A Highly Functionalized Troeger’S Base Derivative Via A Novel Reaction, Daniel Becker, Patricia M. Finnegan, Paul W. Collins Mar 1993

Isolation Of A Highly Functionalized Troeger’S Base Derivative Via A Novel Reaction, Daniel Becker, Patricia M. Finnegan, Paul W. Collins

Chemistry: Faculty Publications and Other Works

Heating a solution of methyl 5-chloro-4-[(ethoxyoxoacetyl) amino]-2-methoxybenz-oate, 3 in DMSO gave rise to the formation of the highly substitute


Minimizing Channel Density With Movable Terminals, Ronald I. Greenberg, Jau-Der Shih Mar 1993

Minimizing Channel Density With Movable Terminals, Ronald I. Greenberg, Jau-Der Shih

Computer Science: Faculty Publications and Other Works

We give algorithms to minimize density for channels with terminals that are movable subject to certain constraints. The main cases considered are channels with linear order constraints, channels with linear order constraints and separation constraints, channels with movable modules containing fixed terminals, and channels with movable modules and terminals. In each case, previous results for running time and space are improved by a factor of L/lg n and L , respectively, where L is the channel length and n is the number of terminals.


Electrochemical Studies Of Swelling And Shrinking Of Clay Films, Jia Du Jan 1993

Electrochemical Studies Of Swelling And Shrinking Of Clay Films, Jia Du

Master's Theses

No abstract provided.


A Clay Modified Electrode For Ion-Exchange Voltammetry, Thaddeus S. Wielgos Jan 1993

A Clay Modified Electrode For Ion-Exchange Voltammetry, Thaddeus S. Wielgos

Master's Theses

No abstract provided.


Reactions Of 1-Triptycyl Carbinol And Bis-(1-Triptycyl)-Carbinol, Bryce Arthur Milleville Jan 1993

Reactions Of 1-Triptycyl Carbinol And Bis-(1-Triptycyl)-Carbinol, Bryce Arthur Milleville

Master's Theses

No abstract provided.


Nmr Study Of Na+-H+ And Na+-Li+ Exchange In Human Erythrocytes, Suilan Mo Jan 1993

Nmr Study Of Na+-H+ And Na+-Li+ Exchange In Human Erythrocytes, Suilan Mo

Master's Theses

No abstract provided.


Correlation Of 17o Chemical Shifts Of Chromium Carbene Complexes With Moss' Mxy Reacitvity Parameter, Shuyuan Liao Jan 1993

Correlation Of 17o Chemical Shifts Of Chromium Carbene Complexes With Moss' Mxy Reacitvity Parameter, Shuyuan Liao

Master's Theses

No abstract provided.


The Interaction Of Sickle Hemoglobin With Phosphatidylserine Vesicles ; Fourier Transform Infrared Spectroscopic Studies Of Human Erythrocyte Spectrin, Cynthia C. Labrake Jan 1993

The Interaction Of Sickle Hemoglobin With Phosphatidylserine Vesicles ; Fourier Transform Infrared Spectroscopic Studies Of Human Erythrocyte Spectrin, Cynthia C. Labrake

Dissertations

No abstract provided.


A Facile Route To Allylic Phosphonates Via Base-Catalyzed Isomerization Of The Corresponding Vinyl Phosphonates : Remote Dianions In Synthesis, Synthetic Approaches To The Indolizidines, James J. Kiddle Jan 1993

A Facile Route To Allylic Phosphonates Via Base-Catalyzed Isomerization Of The Corresponding Vinyl Phosphonates : Remote Dianions In Synthesis, Synthetic Approaches To The Indolizidines, James J. Kiddle

Dissertations

No abstract provided.


Catecholamine Secretion In Bovine Chromaffin Cells : Influence Of Immune-Derived Factors, Zhaohui Wang Jan 1993

Catecholamine Secretion In Bovine Chromaffin Cells : Influence Of Immune-Derived Factors, Zhaohui Wang

Master's Theses

No abstract provided.


Polynuclear Mixed-Valence Complexes, David A. Rockcliffe Jan 1993

Polynuclear Mixed-Valence Complexes, David A. Rockcliffe

Dissertations

No abstract provided.


Effect Of Solvent On 1,3-Dipolar Cycloaddition Transition States, Sheila Louise Celsor Jan 1993

Effect Of Solvent On 1,3-Dipolar Cycloaddition Transition States, Sheila Louise Celsor

Dissertations

No abstract provided.