Physical Sciences and Mathematics Commons^™

On Clock Routing Techniques For Vlsi Synchronous Systems, Wasim A. Khan

Masters Theses

The clock signal is vital in maintaining proper dataflow, and thus the total throughput, of a high performance synchronous system.

In this thesis, we develop a clock distribution scheme for high performance systems which maximizes the operating clock frequency. We develop an algorithm which routes a planar clock tree with zero skew, minimum source to sink pathlength, and minimal total wirelength. The algorithm also provides a smooth tradeoff between maximum source to sink pathlength and total wirelength while keeping the clock skew at zero.

In many microprocessor designs, multi-phase clocks are used for improved system design. Routing a multiple clock …

Fast Accurate Simulation Of Large Shared Memory Multiprocessors, Bob Boothe Phd

Faculty Publications

Fast computer simulation is an essential tool in the design of large parallel computers. Our Fast Accurate Simulation Tool, FAST, is able to accurately simulate large shared memory multiprocessors and their execution of parallel applications at simulation speeds that are one to two orders of magnitude faster than previous comparable simulators. The key ideas involve execution driven simulation techniques that modify the object code of the application program being studied. This produces an augmented version of the code that is directly executed and performs much of the work of the simulation. We extend the previous work by introducing several new …

Anns An X Window Based Version Of The Afit Neural Network Simulator, Ching-Seh Wu

Theses and Dissertations

This thesis presents an X Window based neural network simulation environment developed at Air Force Institute of Technology (AFIT) using the techniques of modern software engineering. This artificial neural network simulator is a tool running on Sun SPARCstations and supporting two user modes: end-users and client-programmers. End-users interact with neural network paradigms developed by client-programmers for the purpose of studying and analyzing the execution of a particular Neural Network (NN) paradigm, or class of NN algorithms. Client programmers maintain the system and use this environment for the development of new NN paradigms or algorithms for end-users. The development follows a …

A Decision Criteria To Select An Associative-Memory Organization That Minimizes The Execution Time Of A Mix Of Associative-Search Operations, David W. Banton

Theses and Dissertations

The dissertation develops a decision criteria to select an associative-memory organization that minimizes the execution time of a mix of associative-search operations and a decision criteria to estimate the layout dimensions of each organization for a specified memory size. The dissertation reclassifies Feng's associative-search operations into three hardware-influenced categories: bit-position independent (BPI), record-content independent (RCI); bit-position dependent (BPD), RCI; and BPD, record-content dependent (RCD). It develops a relationship between the categories and three associative-memory organizations: the CAM, the bit-serial word-parallel associative memory (BSWPAM) , and the extreme-search associative memory (ESAM). A version of the CAM, three versions of the BSWPAM, …

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 …

Assessment Of The Accuracy Of Three Methods Of Computerized Growth Prediction Of The Soft Tissue Profile, In Untreated Individuals, Pat Diciccio

Loma Linda University Electronic Theses, Dissertations & Projects

This study was performed to determine the accuracy and reliability of the long range growth predictions for profile structures by three computer software systems (QuickCeph™ for Apple Macintosh™ systems. Rocky Mountain Data Systems™ for IBM™ mainframe systems, and Facial Print™ for IBM™ personal computers), on untreated individuals. The total sample consisted of 90 Caucasian children from the Burlington Growth Centre. These were subdivided into groups of 15 children in each of mesiofacial, dolichofacial, and brachyfacial growth types for both males and females, with Angle class I occlusions, normal overbite, and normal overjet. Points measured consisted of 14 skeletal and soft …

Ua66/3/2 Computer Science Alumni Newsletter, Vol. 8, Wku Computer Science

WKU Administration Documents

Newsletter created by WKU Computer Science for alumni of the program. This issue includes list of faculty research and scholarly activity and results of alumni survey.

Integrating Theory And Practice In Parallel File Systems, Thomas H. Cormen, David Kotz

Dartmouth Scholarship

Several algorithms for parallel disk systems have appeared in the literature recently, and they are asymptotically optimal in terms of the number of disk accesses. Scalable systems with parallel disks must be able to run these algorithms. We present for the first time a list of capabilities that must be provided by the system to support these optimal algorithms: control over declustering, querying about the configuration, independent I/O, and turning off parity, file caching, and prefetching. We summarize recent theoretical and empirical work that justifies the need for these capabilities. In addition, we sketch an organization for a parallel file …

Algorithms For Generation Of Path-Methods In Object-Oriented Databases, Ashish Mehta

Dissertations

A path-method is a mechanism in object-oriented databases (OODBs) to retrieve or to update information relevant to one class that is not stored with that class but with some other class. A path-method is a method which traverses from one class through a chain of connections between classes to access information at another class. However, it is a difficult task for a user to write path-methods, because it might require comprehensive knowledge of many classes of the conceptual schema, while a typical user has often incomplete or even inconsistent knowledge of the schema.

This dissertation proposes an approach to the …

Dmodel And Dalgebra : A Data Model And Algebra For Office Documents, Fortune Solani Mhlanga

Dissertations

This dissertation presents a data model (called D_model) and an algebra (called D_ algebra) for office documents. The data model adopts a very natural view of modeling office documents. Documents are grouped into classes; each class is characterized by a "frame template", which describes the properties (or attributes) for the class of documents. A frame template is instantiated by providing it with values to form a "frame instance" which becomes the synopsis of the document of the class associated with the frame template. Different frame instances can be grouped into a folder. Therefore, a folder is a set of frame …

Megsdf Mega-System Development Framework, Tamar Zemel

Dissertations

A framework for developing large, complex software systems, called Mega-Systems, is specified. The framework incorporates engineering, managerial, and technological aspects of development, concentrating on an engineering process. MegSDF proposes developing Mega-Systems as open distributed systems, pre-planned to be integrated with other systems, and designed for change.

At the management level, MegSDF divides the development of a Mega-System into multiple coordinated projects, distinguishing between a meta-management for the whole development effort, responsible for long-term, global objectives, and local managements for the smaller projects, responsible for local, temporary objectives.

At the engineering level, MegSDF defines a process model which specifies the tasks …

Implementing A Tool For Designing Portable Parallel Programs, Geetha Chitti

Theses

The Implementation aspects of a novel parallel programming model called Cluster-M is presented in this thesis. This model provides an environment for efficiently designing highly parallel portable software. The two main components of this model are Cluster-M Specifications and Cluster-M Representations. A Cluster-M Specification consists of a number of clustering levels emphasizing computation and communication requirements of a parallel solution to a given problem. A Cluster-M Representation on the other hand, represents a multi-layered partitioning of a system graph corresponding to the topology of the target architecture. A set of basic constructs essential for writing Cluster-M Specifications using PCN are …

Recursive Soft Morphological Filters, Padmaja Puttagunta

Theses

Mathematical morphology which is based on set-theoretic concept, extracts object features by choosing a suitable structuring shape as a probe. Morphological filters are set operations that transform an image into a quantitative description of its geometrical structure: Appropriately used, they can eliminate noises or irrelevancies while preserv¬ing the details of the original image. The applications of morphological filters in image processing and analysis are numerous, which include shape recognition, industrial parts inspection, nonlinear filtering, and biomedical image processing.

Soft morphological filters are used for smoothing signals with the advantage of being less sensitive to additive noises and to small variations …

Techniques Of Petri Net Reduction, Sreeranga Kalavapalli

Theses

Petri Nets have the capability to analyze large and complex concurrent systems. However, there is one constraint. The number of reachability states of the concurrent systems outweighs the capability of Petri Nets. Previous Petri Net reduction techniques focussed on reducing a subnet to a single transition and hence not powerful enough to reduce a Petri Net. This paper presents six reduction rules and discusses their drawbacks. A new reduction technique called Knitting Technique to delete paths of a Petri Net while retaining all the properties of the original net is presented. Further Structural matrix which facilitates reduction is presented.

Implementation Of An Object-Oriented University Database Using Vodak/Vml Prototype-2/C++, Bheeman Lingan, Madhumathi Tulasiram

Theses

Object-oriented database (OODB) technology has become very popular and successful in recent years. Currently, there are many commercial object-oriented database systems available that are used for developing large and complex real world applications. In addition, there are many research prototypes of object-oriented databases available. In a joint research project of the CIS Dept at NJIT and GMD-IPSI an object-oriented data model called the Dual Model was developed. Using this Dual Model a university environment database schema was designed. This univesity database schema was implemented using the VODAK/VML OODB prototype - 1. The university database was then reimplemented using the C++ …

Classification Of Patterns In Eeg Recordings : A Comparison Of Back-Propagation Networks Vs. Predictive Autoencoder Networks, Brian Armieri

Theses

Recent research exploring the use of neural networks for electro-encephalogram (EEG) pattern classification has found that a three-layer back-propagation network could be successfully trained to identify high voltage spike-and-wave spindle (HVS) patterns caused by epileptic seizures (Jando et. al., in press). However, there is no reason to predict that back-propagation is the best possible network architecture for EEG classification. A back-propagation neural network and a predictive autoencoder neural network were compared to determine which network was better at correct classifying both HVS and non-HVS patterns.

Both networks were able to classify 88%-89% of all patterns using a limited set of …

Graphical Deep Knowledge Representation In Vodak/Vml Object-Oriented Database, Jue Wang

Theses

Applying Object-oriented concepts to the design of complex graphical interface has received great attention in the database and knowledge representation disciplines. Traditional CAD systems can not support efficient environments for design processes because they store information about all the objects for display purposes but do not store any knowledge for reasoning purposes. They are called "knowledge poor". "Graphical Deep Knowledge" in Artificial Intelligence has been proven successful to represent knowledge about objects for display purposes as well as reasoning purposes. We introduwd the theory of "Graphical Deep Knowledge" into the object-oriented database s stem VML to design a "Knowledge rich" …

Throughput Of Existing Multiprocessor File Systems (An Informal Study), David Kotz

Computer Science Technical Reports

Fast file systems are critical for high-performance scientific computing, since many scientific applications have tremendous I/O requirements. Many parallel supercomputers have only recently obtained fully parallel I/O architectures and file systems, which are necessary for scalable I/O performance. Scalability aside, I show here that many systems lack sufficient absolute performance. I do this by surveying the performance reported in the literature, summarized in an informal table.

The State Of Computer Science Facilities Of Schools Across The United States That Are Comparable To Illinois Wesleyan University, Sarah A. Bartz '93

Honors Projects

The purpose of this study is to compare Illinois Wesleyan's academic computer facilities with those at other comparable U.S. colleges and universities. This study also investigates factors affecting these facilities such as the methods other institutions use to deal with and plan for the constantly changing computer world. To obtain this information a survey was mailed to over 250 institutions across the U.S. that were considered comparable to IWU. These institutions include the Associated Colleges of the Midwest, the Oberlin Group, and some of the top colleges and universities in the U.S. as ranked in U.S. News and World Report's …

Diagnosis Of Malignant Melanoma Using A Neural Network, Anurag Chawla, Fikret ErçAl

Computer Science Technical Reports

Malignant melanoma is the deadliest form of all skin cancers. Approximately 32,000 new cases of malignant melanoma were diagnosed in 1991, with approximately 80 percent of patients expected to survive five years [1], Fortunately, if detected early, even malignant melanoma may be treated successfully. Thus, in recent years, there has been a rising interest in the automated detection and diagnosis of skin cancer, particularly malignant melanoma [2]. In this thesis, a novel neural network approach for the automated distinction of melanoma from three benign categories of tumors which exhibit melanoma-like characteristics is presented. The approach is based on devising new …

Cartographic Pattern Recognition Using Template Matching, Angela G. Lammers, Ralph W. Wilkerson, Fikret ErçAl

Computer Science Technical Reports

In creating digital maps from paper maps, the paper map must first be scanned to produce a raster image, and then converted into vector format. Vector format allows non-graphical cartographic information to be stored along with the graphical objects. At the United States Geological Survey, the conversion from raster to vector format is performed by a commercial software package. The package also attempts to classify the graphical objects based on shape, line patterns, and other information gained from the raster file. Since the package frequently fails to classify a significant percentage of the elements in the map, manual map analysis …

An Analysis Of Modern Cryptosystems, Thomas Gerald Sauder, Chung You Ho

Computer Science Technical Reports

Since the ancient Egyptian empire, man has searched for ways to protect information from getting into the wrong hands. Julius Caesar used a simple substitution cipher to protect secrets. During World War II, the Allies and the Axis had codes that they used to protect information. Now that we have computers at our disposal, the methods used to protect data in the past are ineffective. More recently, computer scientists and mathematicians have been working diligently to develop cryptosystems which will provide absolute security in a computing environment.

The three major cryptosystems in use today are DES, RSA, and the Knapsack …

Parallel Genetic Algorithms For The Dag Vertex Splitting Problem, Matthias Mayer, Fikret ErçAl

Computer Science Technical Reports

Directed Acyclic Graphs are often used to model circuits and networks. The path length in such Directed Acyclic Graphs represents circuit or network delays. In the vertex splitting problem, the objective is to determine a minimum number of vertices from the graph to split such that the resulting graph has no path of length greater than a given δ. The problem has been proven to be NP-hard.

A Sequential Genetic Algorithm has been developed to solve the DAG Vertex Splitting Problem. Unlike a standard Genetic Algorithm, this approach uses a variable chromosome length to represent the vertices that split the …

The Interpolating Random Spline Cryptosystem And The Chaotic-Map Public-Key Cryptosystem, Fengi Hwu, Chung You Ho

Computer Science Technical Reports

The feasibility of implementing the interpolating cubic spline function as encryption and decryption transformations is presented. The encryption method can be viewed as computing a transposed polynomial. The main characteristic of the spline cryptosystem is that the domain and range of encryption are defined over real numbers, instead of the traditional integer numbers. Moreover, the spline cryptosystem can be implemented in terms of inexpensive multiplications and additions.

Using spline functions, a series of discontiguous spline segments can execute the modular arithmetic of the RSA system. The similarity of the RSA and spline functions within the integer domain is demonstrated. Furthermore, …

The Design, Analysis, And Implementation Of Parallel Simulated Annealing And Parallel Genetic Algorithms For The Composite Graph Coloring Problem, Brent S. Elmer, Billy E. Gillett

Computer Science Technical Reports

The composite graph coloring problem (CGCP) is similar to the standard graph coloring problem (SGCP). Associated with each vertex of a composite graph is a positive integer which represents the chromaticity of that vertex. This number is the number of consecutive integers (colors) which must be assigned to the vertex. The goal of the CGCP is to color the graph with as few colors as possible. The largest integer used in the coloring is called the chromatic number of the graph. The CGCP is proven to be NP-complete.

Exact, heuristic, and stochastic methods are analyzed and compared. Exact methods are …

Considerations For Rapidly Converging Genetic Algorithms Designed For Application To Problems With Expensive Evaluation Functions, Richard Patrick Rankin, Ralph W. Wilkerson

Computer Science Technical Reports

A genetic algorithm is a technique designed to search large problem spaces using the Darwinian concepts of evolution. Solution representations are treated as living organisms. The procedure attempts to evolve increasingly superior solutions. As in natural genetics, however, there is no guarantee that the optimum organism will be produced.

One of the problems in producing optimal organisms in a genetic algorithm is the difficulty of premature convergence. Premature convergence occurs when the organisms converge in similarity to a pattern which is sub-optimal, but insufficient genetic material is present to continue the search beyond this sub-optimal level, called a local maximum. …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 9, Number 5, May 1993, 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.

On The Multisearching Problem For Hypercubes, Mikhail J. Atallah, Andreas Fabri

Department of Computer Science Technical Reports

No abstract provided.

Broadcast Methods In The Multiswitch Point-To-Point Network, Douglas E. Comer, Victor Norman

Department of Computer Science Technical Reports

No abstract provided.

Some Experiments With A Basic Linear Algebra Routine On Distributed Memory Parallel Systems, H. Byun, Elias N. Houstis, E. A. Vavalis

Department of Computer Science Technical Reports

No abstract provided.