Physical Sciences and Mathematics Commons^™

Applications Of Parallel I/O, David Kotz

Computer Science Technical Reports

Scientific applications are increasingly being implemented on massively parallel supercomputers. Many of these applications have intense I/O demands, as well as massive computational requirements. This paper is essentially an annotated bibliography of papers and other sources of information about scientific applications using parallel I/O. It will be updated periodically.

Tuning Starfish, David Kotz

Computer Science Technical Reports

STARFISH is a parallel file-system simulator we built for our research into the concept of disk-directed I/O. In this report, we detail steps taken to tune the file systems supported by STARFISH, which include a traditional parallel file system (with caching) and a disk-directed I/O system. In particular, we now support two-phase I/O, use smarter disk scheduling, increased the maximum number of outstanding requests that a compute processor may make to each disk, and added gather/scatter block transfer. We also present results of the experiments driving the tuning effort.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 8, October 1996, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

A ten page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

A Fast Parallel Implementation Of The Wavelet Packet Best Basis Algorithm On The Mp-2 For Real-Time Mri, Sumit Chawla, Dennis M. Healy Jr

Computer Science Technical Reports

Adaptive signal representations such as those determined by best-basis type algorithms have found extensive application in image processing, although their use in real-time applications may be limited by the complexity of the algorithm. In contrast to the wavelet transform which can be computed in O(n) time, the full wavelet packet expansion required for the standard best basis search takes O(n log n) time to compute. In the parallel world, however, both transforms take O(log n) to compute when the number of processors equal the number of data elements, making the wavelet packet expansion attractive to implement. This note describes near …

Scene Change Detection For Video Database Management Systems-A Survey, Haitao Jiang, Abdelsalam (Sumi) Helal, Ahmed K. Elmagarmid, Anupam Joshi

Department of Computer Science Technical Reports

No abstract provided.

An Algorithm For Estimating All Matches Between Two Strings, Mikhail J. Atallah, Frédéric Chyzak, Philippe Dumas

Department of Computer Science Technical Reports

No abstract provided.

A Reference Model For Firewall Technology And Its Implications For Connection Signaling, J. Bryan Lyles, Christoph L. Scuba

Department of Computer Science Technical Reports

No abstract provided.

The 42 Equivalence Classes Of Quadratic Surfaces In Affine N-Space, Jörg Peters, Ulrich Reif

Department of Computer Science Technical Reports

No abstract provided.

Analysis Of Algorithms Generalizing B- Spline Subdivision, Jörg Peters, Ulrich Reif

Department of Computer Science Technical Reports

No abstract provided.

Techniques Of The Average Case Analysis Of Algorithms, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

Backtracking, Alberto Apostolico, Giuseppe F. Italiano

Department of Computer Science Technical Reports

No abstract provided.

Smoothing Polyhedra Using Trimmned Bicubic Patches, Jörg Peters

Department of Computer Science Technical Reports

No abstract provided.

Analytical Depoissonization And Its Applications, Philippe Jacquet, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.

On The Portability Of Behavioral Vhdl-93, Krishnaprasad Thirunarayan, Robert Ewing

Kno.e.sis Publications

Goossens defined a structural operational semantics for a subset of VHDL-87 and proved that the parallelism present in VHDL is benign. We extend this work to include shared variables in VHDL-93 that changes the underlying semantic model. In the presence of shared variables, non-deterministic execution of VHDL-93 processes destroys the unique meaning property. We identify and characterize a class of portable VHDL-93 descriptions for which unique meaning property can be salvaged.

An Evidential Reasoning Approach To Attribute Value Conflict Resolution In Database Integration, Ee Peng Lim, Jaideep Srivastava, Shashi Shekhar

Research Collection School Of Computing and Information Systems

Resolving domain incompatibility among independently developed databases often involves uncertain information. DeMichiel [1] showed that uncertain information can be generated by the mapping of conflicting attributes to a common domain, based on some domain knowledge. In this paper, we show that uncertain information can also arise when the database integration process requires information not directly represented in the component databases, but can be obtained through some summary of data. We therefore propose an extended relational model based on Dempster-Shafer theory of evidence [2] to incorporate such uncertain knowledge about the source databases. The extended relation uses evidence sets to represent …

Images 2.1 : An Integrated Model Of An Arid Grazing System, Z G. Yan, K M. Wang

Resource management technical reports

The name IMAGES stands for An Integrated Model of an Arid Grazing Ecological System. The model was initiated by Dr R. Hacker in 1987-8 as an activity to (1) evaluate alternative management strategies and (2) identify key ecological processes and research priorities in shrub rangelands of Western Australia. Version 1 of the model was published in Agriculture Systems in 1991 (Hacker et al. 1991) and here after will be referred to as IMAGES 1. IMAGES 1 is a vegetation model, capable of predicting the prob ility of recruitment and mortality of the desirable species in a given vegetation type under …

An Empirical Comparison Of Networks And Routing Strategies For Parallel Computation, Ronald I. Greenberg, Lee Guan

Computer Science: Faculty Publications and Other Works

This paper compares message routing capabilities of important networks proposed for general-purpose parallel computing. All the networks have been proven to have some type of universality property, i.e., an ability to simulate other networks of comparable cost with modest slowdown, using appropriate cost and communication models. But in this paper we seek an empirical comparison of communication capability under typical direct use rather than an analysis of worst-case results for simulating message traffic of another network.

A Fertility Channel Model For Post-Correction Of Continuous Speech Recognition, Eric K. Ringger, James F. Allen

Faculty Publications

We have implemented a post-processor called SPEECHPP to correct word-level errors committed by an arbitrary speech recognizer. Applying a noisy-channel model, SPEECHPP uses a Viterbi beam-search that employs language and channel models. Previous work demonstrated that a simple word-for-word channel model was sufficient to yield substantial incieases in word accuracy. This paper demonstrates that some improvements in word accuracy result from augmenting the channel model with an account of word fertility in the channel. This work further demonstrates that a modern continuous speech recognizer can be used in "black-box" fashion for robustly recognizing speech for which the recognizer was not …

Procedurally Rational Decision-Making And Control, Richard L. Frost, Michael A. Goodrich, Wynn C. Stirling

Faculty Publications

Substantive rationality requires a decision-maker to be a utility maximizer; under this paradigm, the decision is paramount, and not dependent on the computational process used to obtain it. Procedural rationality is dependent on the method used to make the decision; reasonableness of the procedure is paramount. Well-formed problems are amenable to substantive rationality; ill-formed problems are not, but are amenable to procedural rationality. To qualify as being procedurally rational, a methodology must possess a sound epistemological basis, it must be amenable to a formal design synthesis procedure, and it must be consistent with substantive rationality. Epistemic utility theory forms the …

A Computational Paradigm On Network-Based Models Of Computation, Venkatavasu Bokka

Computer Science Theses & Dissertations

The maturation of computer science has strengthened the need to consolidate isolated algorithms and techniques into general computational paradigms. The main goal of this dissertation is to provide a unifying framework which captures the essence of a number of problems in seemingly unrelated contexts in database design, pattern recognition, image processing, VLSI design, computer vision, and robot navigation. The main contribution of this work is to provide a computational paradigm which involves the unifying framework, referred to as the multiple Query problem, along with a generic solution to the Multiple Query problem.

To demonstrate the applicability of the paradigm, a …

File-Access Characteristics Of Parallel Scientific Workloads, Nils Nieuwejaar, David Kotz, Apratim Purakayastha, Carla Schlatter Ellis, Michael L. Best

Dartmouth Scholarship

Phenomenal improvements in the computational performance of multiprocessors have not been matched by comparable gains in I/O system performance. This imbalance has resulted in I/O becoming a significant bottleneck for many scientific applications. One key to overcoming this bottleneck is improving the performance of multiprocessor file systems. \par The design of a high-performance multiprocessor file system requires a comprehensive understanding of the expected workload. Unfortunately, until recently, no general workload studies of multiprocessor file systems have been conducted. The goal of the CHARISMA project was to remedy this problem by characterizing the behavior of several production workloads, on different machines, …

Resource/Dataflow Graph Operating System Development, Sriram J. Coimbatore

Electrical & Computer Engineering Theses & Dissertations

Implementation of a new dataflow schedule model is the objective of this thesis. The dataflow model algorithm called the resource/dataflow graph model is implemented on a peer-to-peer communication network comprising of six personal computers. This dataflow model is implemented making use of an earlier dataflow model called ATAMM (Algorithm to Architecture Mapping Model) developed by ODU and National Aeronautics and Space Administration (NASA). Development issues include modification of the RDFG testbed operating system and a scheme to transfer data buffers using the ethernet channel from one processor to another processor. This, in turn, equips each sub-module of an application with …

Monte Carlo Simulations Of Photoemission Characteristics From Gaas And Diamond, Abhishek Srivastava

Electrical & Computer Engineering Theses & Dissertations

Monte Carlo based numerical simulations were performed to study photoemission from GaAs and diamond. The central goal was to assess the potential for NEA photoemission from diamond, and to predict its characteristics. The GaAs material system was also included in the simulation study to provide: (i) calibration and validation of the numerical model developed by carefully matching the simulation results with available experimental data, and (ii) quantitative comparisons between the response characteristics of diamond and the better known GaAs system.

Predictions of the energy distribution, temporal response and angular distribution of emitted electrons were obtained. Effects of various parameters, such …

Ua12/2/1 College Heights Herald, Vol. 72, No. 9, Wku Student Affairs

WKU Administration Documents

WKU campus newspaper reporting campus, athletic and Bowling Green, Kentucky news.

Regular features include:

• Just a Second
• Campus Line
• For the Record / Crime Reports
• People Poll
• Sports
• Diversions
• Movie Reviews
• Classifieds

Articles in this issue:

• Brewer, Jerry. NAACP: Blacks Have Obligation to Vote
• VanWinkle, Cara. Houses Hub of Activities – Fraternities & Sororities
• Brown, Karen. Gordon Parks’ Struggle to Success Provides Encouragement
• Stamper, John. Police Continue Hunt for Gunman
• Government Shouldn’t Regulate Morality
• Harbaugh, Jack. School Spirit Strong
• Wilson, Randy. Military Still Needed
• Craig, Ryan. Love is More Than Tight Jeans
• Flanagan, Beth. Greed: The Downfall of America
• Krenzin, …

Run-Time Security Evaluation: Can We Afford It?, Cristina Serban, Bruce M. Mcmillin

Computer Science Faculty Research & Creative Works

The use of the run-time security evaluation (RTSE) method for a distributed application takes a toll in overall application performance. The associated overhead and its major sources are discussed, along with possible solutions for improvements, and questions that remain still open.

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 12, Number 7, September 1996, College Of Engineering And Computer Science, Wright State University

BITs and PCs Newsletter

An eight page newsletter created by the Wright State University College of Engineering and Computer Science that addresses the current affairs of the college.

Prognozowanie Wpływu Motoryzacji Na Poziom Stężenia Ozonu W Przyziemnej Warstwie Atmosfery, Marek Bogacki, Marian Mazur, Robert Oleniacz

Robert Oleniacz

The paper presents an approach for assessing the impact of road transport on the level of ozone concentrations in the ground layer of the atmosphere. The developed method consists in emission inventory on the analyzed area for road transport and calculations using the model of chemical reactions in the troposphere.

Using this method it is possible to display waveforms daily ozone concentrations in the air, and evaluate the effectiveness of the decisions related to the prevention of occurrence of photochemical smog in urban and industrial agglomerations.

English title: Predicting the impact of motoring on the level of ozone concentration in …

Physical Modeling For Interaction In Real-Time Simulation, Curtis Lisle

Link Foundation Modeling, Simulation and Training Fellowship Reports

The goal of this project was to model objects in a simulated environment with a method which allows physically-correct behavior to be calculated in real-time. Our approach studied the interaction between differing object types and used object-oriented software design to create a class hierarchy of objects suitable for interactive speed virtual environment simulation. We studied physical modeling systems and constraint systems as techniques to control the behavior of objects in our simulations. We also studied two different ways to achieve distributed execution of an object-oriented simulation. In our first approach, we designed a set of simulation software which ran built …

Early Experiences In Evaluating The Parallel Disk Model With The Vic* Implementation, Thomas H. Cormen, Melissa Hirschl

Computer Science Technical Reports

Although several algorithms have been developed for the Parallel Disk Model (PDM), few have been implemented. Consequently, little has been known about the accuracy of the PDM in measuring I/O time and total time to perform an out-of-core computation. This paper analyzes timing results on a uniprocessor with several disks for two PDM algorithms, out-of-core radix sort and BMMC permutations, to determine the strengths and weaknesses of the PDM. The results indicate the following. First, good PDM algorithms are usually not I/O bound. Second, of the four PDM parameters, two (problem size and memory size) are good indicators of I/O …

Analysis Of An Asymmetric Leader Election Algorithm, Svante Janson, Wojciech Szpankowski

Department of Computer Science Technical Reports

No abstract provided.