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1995

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Articles 1531 - 1560 of 2193

Full-Text Articles in Physical Sciences and Mathematics

Note On Algol And Conservatively Extending Functional Programming, Peter W. O'Hearn Jan 1995

Note On Algol And Conservatively Extending Functional Programming, Peter W. O'Hearn

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

A simple Idealized Algol is considered, based on Reynolds's "essence of Algol." It is shown that observational equivalence in this language conservatively extends observational equivalence in its assignment-free functional sublanguage.


Irregular Personalized Communication On Distributed Memory Machines, Sanjay Ranka, Jhy-Chun Wang Jan 1995

Irregular Personalized Communication On Distributed Memory Machines, Sanjay Ranka, Jhy-Chun Wang

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

In this paper we present several algorithms for performing all-to-many personalized communication on distributed memory parallel machines. We assume that each processor sends a different message (of potentially different size) to a subset of all the processors involved in the collective communication. The algorithms are based on decomposing the communication matrix into a set of partial permutations. We study the effectiveness of our algorithms both from the view of static scheduling and from runtime scheduling.


Run-Time Support For Parallelization Of Data-Parallel Applications On Adaptive And Nonuniform Computational Environments, Maher Kaddoura, Sanjay Ranka Jan 1995

Run-Time Support For Parallelization Of Data-Parallel Applications On Adaptive And Nonuniform Computational Environments, Maher Kaddoura, Sanjay Ranka

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

In this paper we discuss the runtime support required for the parallelization of unstructured data parallel applications on nonuniform and adaptive environments. The approach presented is reasonably general and is applicable to a wide variety of regular as well as irregular applications. We present performance results for the solution of an unstructured mesh on a cluster of heterogeneous workstations.


The Expressiveness Of Locally Stratified Programs, Howard A. Blair, Wiktor Marek, John S. Schlipf Jan 1995

The Expressiveness Of Locally Stratified Programs, Howard A. Blair, Wiktor Marek, John S. Schlipf

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

This paper completes an investigation of the logical expressibility of finite, locally stratified, general logic programs. We show that every hyperarithmetic set can be defined by a suitably chosen locally stratified logic program (as a set of values of a predicate over its perfect model). This is an optimal result, since the perfect model of a locally stratified program is itself an implicitly definable hyperarithmetic set (under a recursive coding of the Herbrand base); hence to obtain all hyperarithmetic sets requires something new, in this case selecting one predicate from the model. We find that the expressive power of programs …


Communication-Efficient And Memory-Bounded External Redistribution, Jang Sun Lee, Sanjay Ranka, Ravi V. Shankar Jan 1995

Communication-Efficient And Memory-Bounded External Redistribution, Jang Sun Lee, Sanjay Ranka, Ravi V. Shankar

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

This paper presents communication-efficient algorithms for the external data redistribution problem. Deterministic lower bounds and upper bounds are presented for the number of I/O operations, communication time and the memory requirements of external redistribution. Our algorithms differ from most other algorithms presented for out-of-core applications in that it is optimal (within a small constant factor) not only in the number of I/O operations, but also in the time taken for communication. A coarse-grained MIMD architecture with I/O subsystems attached to each processor is assumed, but the results are expected to be applicable over a wider variety of architectures.


Mapping Unstructured Computational Graphs For Adaptive And Nonuniform Computational Environments, Maher Kaddoura, Chao Wei Ou, Sanjay Ranka Jan 1995

Mapping Unstructured Computational Graphs For Adaptive And Nonuniform Computational Environments, Maher Kaddoura, Chao Wei Ou, Sanjay Ranka

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

In this paper we study the problem of mapping a large class of irregular and loosely synchronous data-parallel applications in a nonuniform and adaptive computational environment. The computational structure of these applications can be described in terms of a computational graph, where nodes of the graph represent computational tasks and edges describe the communication between tasks. Parallelization of these applications on nonuniform computational environments requires partitioning the graph among the processors in such fashion that the computation load on each node is proportional to its computational power, while communication is minimized. We discuss the applicability of current methods for graph …


Optimization Using Replicators, Anil Ravindran Menon, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka Jan 1995

Optimization Using Replicators, Anil Ravindran Menon, Kishan Mehrotra, Chilukuri K. Mohan, Sanjay Ranka

College of Engineering and Computer Science - Former Departments, Centers, Institutes and Projects

Replicator systems are among the simplest complex systems and can be considered to be at the foundation of many popularly used models ranging from theories of evolution and neurobiology to sociobiology and ecology. This paper presents the first successful application 2 of replicators to optimization problems. For a graph bi-partitioning problem with 50,000 nodes and 300,000 edges, for instance, close to optimal solutions were obtained in a few hundred iterations. Replicators provide a potentially powerful new tool to solve other optimization problems as well.


Bones Of Puffinus Lherminieri Lesson (Aves: Procellaridae) And Two Other Vertebrates From Cueva Del Agua, Mona Isalnd, Puerto Rico (West Indies), Angel M. Nieves-Rivera, John M. Mylroie, Donald A. Mcfarlane Jan 1995

Bones Of Puffinus Lherminieri Lesson (Aves: Procellaridae) And Two Other Vertebrates From Cueva Del Agua, Mona Isalnd, Puerto Rico (West Indies), Angel M. Nieves-Rivera, John M. Mylroie, Donald A. Mcfarlane

WM Keck Science Faculty Papers

From a dive in Cueva del Agua, Mona Island, Puerto Rico, twelve un-mineralized bones of Puffinus Lherminieri Lesson, one of Cyclura stejnegeri Stejneger, and one of Moormops blainvilii Leach were collected. The subfossil evidence confirms that P. Lherminieri was a common species on Mona Island. Cyclura stejnegeri and M. blainvilii probably became trapped and died in the pool chamber.


Passion Runtime Library For The Intel Paragon, Alok Choudhary, Rajesh Bordawekar, Sachin More, K. Sivaram, Rajeev Thakur Jan 1995

Passion Runtime Library For The Intel Paragon, Alok Choudhary, Rajesh Bordawekar, Sachin More, K. Sivaram, Rajeev Thakur

Electrical Engineering and Computer Science - All Scholarship

We are developing a runtime library which provides a number of routines to perform the I/O required in parallel applications in an efficient and convenient manner. This is part of a project called PASSION, which aims to provide software support for high-performance parallel I/O at the compiler, runtime and file system levels. The PASSION Runtime Library uses a high-level interface which makes it easy for the user to specify the I/O required in the program. The user only needs to specify what portion of the data structure needs to read from or written to the file, and the PASSION routines …


A Simulation Model Of A Surveillance Radar Data Processing System Using Hi-Mass, Steven D. Farr, Alex F. Sisti, Douglas G. Fritz, Robert G. Sargent Jan 1995

A Simulation Model Of A Surveillance Radar Data Processing System Using Hi-Mass, Steven D. Farr, Alex F. Sisti, Douglas G. Fritz, Robert G. Sargent

Electrical Engineering and Computer Science - All Scholarship

This paper discusses the model specification, construction of the executable model, model execution, and the simulation results of a simulation model of a surveillance radar data processing system that was developed using the Hierarchical Modeling and Simulation System (HI-MASS). HI-MASS is an object oriented C++ based system that supports model specification (modeling) using the Hierarchical Control Flow Graph Model paradigm and executes simulation models using the sequential synchronous simulation execution algorithm. Models specified in this model paradigm use two complementary hierarchical specification structures, one to specify the model components and their interconnections and the other to specify the behaviors of …


An Evaluation Of Design Tradeoffs In A High Performance Media-On-Demand Server, Divyesh Jadav, Chutimet Srinilta, Alok Choudhary, P. B. Berra Jan 1995

An Evaluation Of Design Tradeoffs In A High Performance Media-On-Demand Server, Divyesh Jadav, Chutimet Srinilta, Alok Choudhary, P. B. Berra

Electrical Engineering and Computer Science - All Scholarship

One of the key components of a multi-user multimedia-on-demand system is the data server. Digitalization of traditionally analog data such as video and audio, and the feasibility of obtaining network bandwidths above the gigabit-per-second range are two important advances that have made possible the realization, in the near future, of interactive distributed multimedia systems. Secondary-to-main memory I/O technology has not kept pace with advances in networking, main memory and CPU processing power. Consequently, the performance of the server has a direct bearing on the overall performance of such a system. In this paper we present a high-performance solution to the …


National Hpcc Software Exchange, Shirley Browne, Jack Dongarra, Stan Green, Keith Moore, Tom Rowan, Reed Wade, Geoffrey .. Fox, Ken Hawick Jan 1995

National Hpcc Software Exchange, Shirley Browne, Jack Dongarra, Stan Green, Keith Moore, Tom Rowan, Reed Wade, Geoffrey .. Fox, Ken Hawick

Electrical Engineering and Computer Science - All Scholarship

This report describes an effort to construct a National HPCC Software Exchange (NHSE). This system shows how the evolving National Information Infrastructure (NII) can be used to facilitate sharing of software and information among members of the High Performance Computing and Communications (HPCC) community. To access the system use the URL: http://www.netlib.org/nse/.


Verification And Validation Of Simulation Models, Douglas G. Fritz, Robert G. Sargent, Thorsten Daum Jan 1995

Verification And Validation Of Simulation Models, Douglas G. Fritz, Robert G. Sargent, Thorsten Daum

Electrical Engineering and Computer Science - All Scholarship

The Hierarchical Modeling and Simulation System (HI-MASS) is a prototype modeling and simulation system that supports modeling based on the Hierarchical Control Flow Graph Model paradigm and simulation execution using a sequential synchronous simulation algorithm. The prototype is an object oriented C++ based system designed for a Unix environment and implemented using freely available software tools. Models are specified using two complementary hierarchical model specification structures, one to specify the components which comprise a model and how those components are interconnected, and the other to specify the behaviors of the individual components. A graphical user interface provides for component and …


Effects Of Technology Mapping On Fault Detection Coverage In Reprogrammable Fpgas, Kevin A. Kwiat, Warren Debany, Salim Hariri Jan 1995

Effects Of Technology Mapping On Fault Detection Coverage In Reprogrammable Fpgas, Kevin A. Kwiat, Warren Debany, Salim Hariri

Electrical Engineering and Computer Science - All Scholarship

Although Field-Programmable Gate Arrays (FPGAs) are tested by their manufacturers prior to shipment, they are still susceptible to failures in the field. In this paper, test vectors generated for the emulated (i.e., mission) circuit are fault simulated on two different models: the original view of the circuit, and the design as it is mapped to the FPGA's logic cells. Faults in the cells and in the programming logic are considered. Experiments show that this commonly-used approach fails to detect most of the faults in the FPGA.


Vorticity Balance Of Outcropping Isopycnals, G. T. Csanady, G. Vittal Jan 1995

Vorticity Balance Of Outcropping Isopycnals, G. T. Csanady, G. Vittal

CCPO Publications

The authors extend Marshall and Nurser's analysis of potential vorticity (PV) flux into outcropping isopycnic layers of the oceanic thermocline to the nonstationary case, allowing for the seasonal migration of isopycnal surfaces under surface heating and cooling. The most important new result is that the bulk of the surface PV flux arising from seasonal heating is used up in creating stratification as an isopycnal outcrop moves northward, extending the stratified layers of the thermocline. Residual PV transport (flux times the separation distance between adjacent isopycnals) reaching the interior thermocline is small in quiescent regions where only mean advection (connecting to …


Transport, Potential Vorticity, And Current/Temperature Structure Across Northwest Providence And Santaren Channels And The Florida Current Off Cay Sal Bank, Kevin D. Leaman, Peter S. Vertes, Larry P. Atkinson, Thomas N. Lee, Peter Hamilton, Evans Waddell Jan 1995

Transport, Potential Vorticity, And Current/Temperature Structure Across Northwest Providence And Santaren Channels And The Florida Current Off Cay Sal Bank, Kevin D. Leaman, Peter S. Vertes, Larry P. Atkinson, Thomas N. Lee, Peter Hamilton, Evans Waddell

CCPO Publications

Currents and temperatures were measured using Pegasus current profilers across Northwest Providence and Santaren Channels and across the Florida Current off Cay Sal Bank during four cruises from November 1990 to September 1991. On average, Northwest Providence (1.2 Sv) and Santaren (1.8 Sv) contribute about 3 Sv to the total Florida Current transport farther north (e.g., 27°N). Partitioning of transport into temperature layers shows that about one-half of this transport is of ''18°C'' water (17°C-19.5°C); this can account for all of the ''excess'' 18°C water observed in previous experiments. This excess is thought to be injected into the 18°C layer …


Synthesis, Characterization, And Molecular Structure Of Bis(Tetraphenylcyclopentdienyl)Rhodium(Ii)⊗, James E. Collins, Michael Castellani, Arnold L. Rheingold, Edward J. Miller, William E. Geiger, Anne L. Rieger, Philip H. Rieger Jan 1995

Synthesis, Characterization, And Molecular Structure Of Bis(Tetraphenylcyclopentdienyl)Rhodium(Ii)⊗, James E. Collins, Michael Castellani, Arnold L. Rheingold, Edward J. Miller, William E. Geiger, Anne L. Rieger, Philip H. Rieger

Chemistry Faculty Research

A 5 day diglyme reflux of Rh(acac)3 and K(C5HPh4), followed by treatment with aqueous HPF6, produces orange-yellow [(C5HPh4)2Rh]PF66 in 40 - 50% yield. Reduction of [(C5HPh4)2Rh]PF6 with sodium amalgam in THF yields olive green (C5HPh4)2Rh in 70% yield. (C5HPh4)2Rh crystallizes in the triclinic [Error : unloaded OLE object or mail attachment]space group with unit-cell parameters of a = 8.622 (3) Å, b = 10.778 (4) Å, c = 12.894 (5) Å, a = 65.58 (3)°, b = 72.66 (3)°, g = 83.52 (3)°, and Z = 1. The least squares data refined to RF = 7.63% and …


Positive Solutions For Higher Order Ordinary Differential Equations, Paul W. Eloe, Johnny Henderson Jan 1995

Positive Solutions For Higher Order Ordinary Differential Equations, Paul W. Eloe, Johnny Henderson

Mathematics Faculty Publications

Solutions that are positive with respect to a cone are obtained for the boundary value problem, u(n) + a(t)f(u) = 0, u(i)(0) = u(n−2)(1) = 0, 0 _ i _ n − 2, in the cases that f is either superlinear or sublinear. The methods involve application of a _xed point theorem for operators on a cone.


Multipoint Boundary Value Problems For Functional Differential Equations, Paul W. Eloe, Johnny Henderson, Denise Taunton Jan 1995

Multipoint Boundary Value Problems For Functional Differential Equations, Paul W. Eloe, Johnny Henderson, Denise Taunton

Mathematics Faculty Publications

No abstract provided.


Stability Properties And Integrability Of The Resolvent Of Linear Volterra Equations, Muhammad Islam, Paul W. Eloe Jan 1995

Stability Properties And Integrability Of The Resolvent Of Linear Volterra Equations, Muhammad Islam, Paul W. Eloe

Mathematics Faculty Publications

Integrability of the resolvent and the stability properties of the zero solution of linear Volterra integrodifferential systems are studied. In particular, it is shown that, the zero solution is uniformly stable if and only if the resolvent is integrable in some sense. It is also shown that, the zero solution is uniformly asymptotically stable if and only if the resolvent is integrable and an additional condition in terms of the resolvent and the kernel is satisfied. Finally, the integrability of the resolvent is obtained under an explicit condition.


Effects Of Longwall Mining On Hydrogeology, Leslie County, Kentucky Part 1: Pre-Mining Conditions, Shelley A. Minns, James A. Kipp, Daniel I. Carey, James S. Dinger, Lyle V. A. Sendlein Jan 1995

Effects Of Longwall Mining On Hydrogeology, Leslie County, Kentucky Part 1: Pre-Mining Conditions, Shelley A. Minns, James A. Kipp, Daniel I. Carey, James S. Dinger, Lyle V. A. Sendlein

Report of Investigations--KGS

An investigation of the hydrologic effects of longwall coal mining is in progress in the Eastern Kentucky Coal Field. The study area is located in a first-order watershed in southern Leslie County over Shamrock Coal Company's Beech Fork Mine (Edd Fork Basin on the Helton 7.5-minute quadrangle). Longwall panels approximately 700 feet wide are separated by three-entry gateways 200 feet wide. The mine is operating in the Fire Clay coal (Hazard No. 4); overburden thickness ranges from 300 to 1,000 feet. Mining in the watershed began in late summer 1993. Undermining of the instrumented panel (panel 7) is anticipated for …


Dartcvl: The Dartmouth C Vector Library, Thomas H. Cormen, Sumit Chawla, Preston Crow, Melissa Hirschl, Roberto Hoyle, Keith D. Kotay, Rolf H. Nelson, Nils Nieuwejaar, Scott M. Silver, Michael B. Taylor, Rajiv Wickremesinghe Jan 1995

Dartcvl: The Dartmouth C Vector Library, Thomas H. Cormen, Sumit Chawla, Preston Crow, Melissa Hirschl, Roberto Hoyle, Keith D. Kotay, Rolf H. Nelson, Nils Nieuwejaar, Scott M. Silver, Michael B. Taylor, Rajiv Wickremesinghe

Computer Science Technical Reports

As a class project, we implemented a version of CVL, the C Vector Library, on a DECmpp 12000/Sx 2000, which is equivalent to the MasPar MP-2 massively parallel computer. We compare our implementation, DartCVL, to the University of North Carolina implementation, UnCvl.

DartCVL was designed for the MP-2 architecture and UnCvl was designed for the MP-1. Because the MasPar MP-1 and MP-2 are functionally equivalent, both DartCVL and UnCvl will run on either. Differences in the designs of the two machines, however, may lead to different software design decisions. DartCVL differs from UnCvl in two key ways. First, DartCVL uses …


Santa Clara Magazine, Volume 37 Number 1, Winter 1995, Santa Clara University Jan 1995

Santa Clara Magazine, Volume 37 Number 1, Winter 1995, Santa Clara University

Santa Clara Magazine

6 - THE JESUIT CASE DECLASSIFIED Secret documents reveal what the United States knew.... and what it failed to do about the Jesuit murders in El Salvador. By Peter Kornbluh

10 - EASTERN ENLIGHTENMENT SCU's new religion chair draws from her latest book to discuss how Christians can derive a greater understanding of their own faith through an appreciation of Buddhism. By Denise Lardner Carmody

13 - WASTE NOT As part of SCU's Institute on Ecology, students, faculty, and staff assess how well the University is using its own environmental resources.

17 - THE DOMESTIC CHURCH MEETS THE PARISH CHURCH …


Collection Of Athermal Phonons Into Doped Germanium Thermistors Using Quasiparticle Trapping, S. M. Grannan, Betty A. Young, Andrew E. Lange, S. Labov, Bernard Sadoulet, J. Emes, Eugene E. Haller Jan 1995

Collection Of Athermal Phonons Into Doped Germanium Thermistors Using Quasiparticle Trapping, S. M. Grannan, Betty A. Young, Andrew E. Lange, S. Labov, Bernard Sadoulet, J. Emes, Eugene E. Haller

Physics

We have developed a low‐temperature particle detector that uses a novel quasiparticle trapping mechanism to funnel athermal phonon energy from an 80 mg Ge absorber into a 1.6 mg doped Ge thermistor via a superconducting Al film. We report on pulse height spectra obtained at 320 mK by scanning a 241Am alpha source along the device, and show that up to 20% of the energy deposited in the Ge absorber by a 5.5 MeV alpha particle interaction can be collected into a thermistor via quasiparticle trapping. We show that this device is sensitive to the position of an alpha …


Gender Patterns In Science Course Enrollment And Course Drop Patterns In An Iowa Senior High School, Sandra L. Stephen, Elizabeth D. Riesz Jan 1995

Gender Patterns In Science Course Enrollment And Course Drop Patterns In An Iowa Senior High School, Sandra L. Stephen, Elizabeth D. Riesz

Journal of the Iowa Academy of Science: JIAS

In order to ascertain whether local patterns corresponded to the national trends, which show fewer female and minority students enrolling in and completing high school physical science courses, the Cedar Rapids Community School District studied the course enrollment and drop patterns of seniors in one of the District high schools. Male students predominated in physics and AP Chemistry, and the proportion of males in AP Physics was significantly greater than the proportion of females. The proportion of females in chemistry was significantly greater than their proportion in the senior class. Course dropping patterns revealed a statistically significant relationship between gender …


Editorial Board & Iowa Academy Of Science Officers And Directors Jan 1995

Editorial Board & Iowa Academy Of Science Officers And Directors

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Back Cover Jan 1995

Back Cover

Journal of the Iowa Academy of Science: JIAS

No abstract provided.


Paleokarst And Associated Mineralization At The Linwood Mine, Scott County Iowa, Paul L. Garvin Jan 1995

Paleokarst And Associated Mineralization At The Linwood Mine, Scott County Iowa, Paul L. Garvin

Journal of the Iowa Academy of Science: JIAS

Operations at the Linwood Mine in Scott County, Iowa, have exposed, on two working levels, extensive pre-Pennsylvanian paleokarst and associated sediment fillings and mineralization in Middle Devonian limestones. Cavities in Davenport-Spring Grove host rocks range up to 270 meters in length and are virtually all filled with fluviatile sediment. Cavities in Cedar Rapids host rocks, on average, are smaller and some are unfilled. Limestone dissolution was controlled by high-angle fractures with a wide variety of orientations and by bedding plane and stylolitic partings. Dissolutional features on both levels of the mine provide evidence for phreatic and vadose processes. Most of …


Critical Success Factors For Organizational Case Success, Chad Strauss Jan 1995

Critical Success Factors For Organizational Case Success, Chad Strauss

Presidential Scholars Theses (1990 – 2006)

Practitioners and researchers have suggested that Computer Aided Software Engineering (CASE) technology can significantly improve the productivity of systems analysts and the quality of systems development. Before CASE can succeed, however, specific components must exist. This paper explores CASE and the components necessary for its widespread acceptance and use within information systems departments. Specifically, this paper will examine the systems development life cycle (SDLC), the possible benefits of CASE, the current state of CASE, critical success factors for CASE, and finally CASE use.


Biological Processes: Relationships Between Earthworms And Soil Temperature, Edwin C. Berry, Jerry K. Radke Jan 1995

Biological Processes: Relationships Between Earthworms And Soil Temperature, Edwin C. Berry, Jerry K. Radke

Journal of the Minnesota Academy of Science

Soil fauna play important roles in many soil processes and conditions which relate to agricultural systems. Earthworms are credited with enhancing soil fertility and soil physical properties by their feeding and burrowing activities. Most research on earthworms has focused on the warmer seasons of the year and relatively little is known about earthworm activity and survival during the portion of the year with frozen soils. Earthworms may survive winter by acclimatization, aestivation, or by burrowing to deeper depths where the soil is not frozen. More research is needed on the fate of earthworms in frozen soils. Suggested research areas include: …