Hierarchy-Based Access Control In Distributed Environments, Jean-Camille Birget, Xukai Zou, Guevara Noubir, Byrav Ramamurthy

CSE Conference and Workshop Papers

Access control is a fundamental concern in any system that manages resources, e.g., operating systems, file systems, databases and communications systems. The problem we address is how to specify, enforce, and implement access control in distributed environments. This problem occurs in many applications such as management of distributed project resources, e-newspaper and payTV subscription services.

Starting from an access relation between users and resources, we derive a user hierarchy, a resource hierarchy, and a unified hierarchy. The unified hierarchy is then used to specify the access relation in a way that is compact and that allows efficient queries. It is …

Wright State University College Of Engineering And Computer Science Bits And Pcs Newsletter, Volume 17, Number 4, January 2001, 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.

No-Nonsense Guide To Csab/Csac Accreditation, Pete Sanderson

Mathematics Faculty Scholarship

CSAB/CSAC provides professional accreditation of computer science bachelor's degree programs in the United States. As of October 2000, 159 institutions held this accreditation. By our count, over 80% of the accredited programs were offered by departments which also offer graduate programs in computer science. This means that few small colleges are represented. Our intent in this work is to give the small college audience an up-to-date guide to the recently-revised CSAB/CSAC accreditation standards. The guide is not comprehensive; we emphasize those issues we believe to be of greatest interest to small colleges and address them from the perspective we have …

Building An Interactive, Three-Dimensional Virtual World, Raymond Mazza

Senior Scholar Papers

The movement of graphics and audio programming towards three dimensions is to better simulate the way we experience our world. In this project I looked to use methods for coming closer to such simulation via realistic graphics and sound combined with a natural interface. I did most of my work on a Dell OptiPlex with an 800 MHz Pentium III processor and an NVIDlA GeForce 256 AGP Plus graphics accelerator -high end products in the consumer market as of April 2000. For graphics, I used OpenGL [1], an open·source, multi-platform set of graphics libraries that is relatively easy to use, …

On The Nonembeddability And Crossing Numbers Of Some Toroidal Graphs On The Klein Bottle, Adrian Riskin

Mathematics

We show that toroidal polyhedral maps with four or more disjoint homotopic noncontractiblecircuits are not embeddable on the projective plane and that toroidal polyhedral maps with -veor more disjoint homotopic noncontractible circuits are not embeddable on the Klein bottle. Wealso show that the Klein bottle crossing numbers ofCm×Cn(m6n) form=3;4;5;6 are 1,2,4,and 6, respectively, and give upper bounds for all other values ofn. These crossing numbersdispla yat ypical behavior in that the value depends onl yonminstead of on bothmandnas isthe case for the plane and projective plane.

Joachim Castella: Studien Zur Thematik "Kalkül Und Kreativität", Rudolf Kaehr

Rudolf Kaehr

Utopie der Zeichen – Zeichen der Utopie Vilém Flusser und Gotthard Günther als Komplement einer neuen Medienphilosophie Medientheorie als Theoriemedium Prolegomena einer allgemeinenMedientheorie Philosophie des LMR Joachim Castella 2000/2001

Computer Graphics Optique: Optical Superposition Of Projected Computer Graphics, Aditi Majumder

Link Foundation Modeling, Simulation and Training Fellowship Reports

We present some ideas and demonstrations for a hybrid projector-based rendering and display technique we call Computer Graphics Optique. Instead of partially overlapping projected images to achieve a wide-area display, we completely overlap projected images on top of each other to achieve the addition of light and color in an "optical composition buffer''. The idea is to use the optical composition to replace some analytical computation, to increase rendering speed, gain flexibility, intensity range, and intensity resolution. Where projector-based displays are appropriate, potential uses include the optical realization of certain effects normally requiring a digital accumulation buffer, the optical composition …

Complexity As Fitness For Evolved Cellular Automata Update Rules, Em Ward, Doug Blank, Douglas Rolniak, Dale R. Thompson

Computer Science Faculty Research and Scholarship

We investigate the state change behavior of one-dimensional cellular automata during the solution of the binary density-classification task. Update rules of high, low and un- known fitness are applied to cellular au- tomata, thereby providing examples of high and low rates of successful classification. A spread factor, ω, is introduced and investi- gated as a numerical marker of state change behavior. The nature of ω describes complex or particle-like behavior on the part of the cellular automata over the middle region of initial configuration density-distribution, but breaks down at the ends. Because of the lim- itation on ω, a related …

A Robot Team That Can Search, Rescue, And Serve Cookies: Experiments In Multi-Modal Person Identification And Multi-Robot Sound Localization., Doug Blank, G. Beavers

Computer Science Faculty Research and Scholarship

A team of three robots placed second in both the Urban Search and Rescue and Hors d’Oeuvres Anyone? events at the 2000 American Association of Artificial Intelligence au- tonomous robot competitions. This paper describes the multi- robot, low-cost sound localization technique, and the multi- sensor, person recognition system used in the AAAI contests by the robot team.

Rush Hour® And Dijkstra’S Algorithm, Mark Stamp, Brad Engel, Mcintosh Ewell, Victor Morrow

Faculty Publications, Computer Science

The game of Rush Hour® includes a 6 × 6 grid and game pieces representing cars and trucks. The object of the puzzle is to move a special car out of a gridlocked “traffic jam.” In this note we apply Dijkstra’s algorithm and a breadth-first search to solve any Rush Hour configuration.

Privacy-Preserving Cooperative Statistical Analysis, Wenliang Du, Mikhail J. Atallah

Electrical Engineering and Computer Science - All Scholarship

The growth of the Internet opens up tremendous opportunities for cooperative computation, where the answer depends on the private inputs of separate entities. Sometimes these computations may occur between mutually untrusted entities. The problem is trivial if the context allows the conduct of these computations by a trusted entity that would know the inputs from all the participants; however if the context disallows this then the techniques of secure multi-party computation become very relevant and can provide useful solutions. Statistic analysis is a widely used computation in real life, but the known methods usually require one to know the whole …

Secure Multi-Party Computation Problems And Their Applications: A Review And Open Problems, Wenliang Du, Mikhail J. Atallah

Electrical Engineering and Computer Science - All Scholarship

The growth of the Internet has triggered tremendous opportunities for cooperative computation, where people are jointly conducting computation tasks based on the private inputs they each supplies. These computations could occur between mutually untrusted parties, or even between competitors. For example, customers might send to a remote database queries that contain private information; two competing financial organizations might jointly invest in a project that must satisfy both organizations' private and valuable constraints, and so on. Today, to conduct such computations, one entity must usually know the inputs from all the participants; however if nobody can be trusted enough to know …

Inter-Domain Lsp Setup Using Bandwidth Management Points, Ibrahim Taner Okumus, Junseok Hwang, Haci Ali Mantar, Steve J. Chapin

Electrical Engineering and Computer Science - All Scholarship

Bandwidth Management Points (BMP) are a necessity to manage the intra and inter-domain resources in the Internet. In this paper we propose a way to setup inter-domain Label Switched Path (LSP) with the help of a BMP in a MultiProtocol Label Switching (MPLS) over DiffServ network. We use extended Simple Inter-domain Bandwidth Broker Signalling Protocol (SIBBS) to distribute the labels inter-domain. We also use a BMP to interact with the MPLS to setup the intra-domain LSP and to provision the intra-domain traffic. With the help of a BMP, we show how end-to-end Quality of Service (QoS) can be achieved.

Interdomain Resource Reservation Via Third-Party Agent, Haci Ali Mantar, Junseok Hwang, Ibrahim Taner Okumus, Steve J. Chapin

Electrical Engineering and Computer Science - All Scholarship

This paper describes interdomain resource reservation through a third-party agent called a Bandwidth Management Point (BMP). The BMP of each domain is responsible for admission control, dynamic bandwidth provisioning, DSCP assignment, policy control, etc. We also propose that each domain be free to choose its own intradomain resource reservation protocol.This model solves two significant problems of today's Internet: interdomain dynamic resource provisioning, and scalability of the backbone. The BMP makes bulk reservations with each possible destination domain on behalf of hosts in its domain, and end hosts can join or leave the reservation without being involved with communication protocol between …

Parallel Suffix Sorting, Natsuhiko Futamura, Srinivas Aluru, Stefan Kurtz

Electrical Engineering and Computer Science - All Scholarship

We present a parallel algorithm for lexicographically sorting the suffixes of a string. Suffix sorting has applications in string processing, data compression and computational biology. The ordered list of suffixes of a string stored in an array is known as Suffix Array, an important data structure in string processing and computational biology. Our focus is on deriving a practical implementation that works well for typical inputs rather than achieving the best possible asymptotic running-time for artificial, worst-case inputs. We experimentally evaluated our algorithm on an IBM SP-2 using genomes of several organisms. Our experiments show that the algorithm delivers good, …

Jobqueue: A Computational Grid-Wide Queuing System, Dimitros Katramatos, Marty Humphrey, Andrew Grimshaw, Steve Chapin

Electrical Engineering and Computer Science - All Scholarship

In a Computational Grid, it is not easy to maintain grid-wide control over the number of executing jobs, as well as a global view of the status of submitting jobs, due to the heterogeneity in resource type, availability, and access policies. This paper describes the design and implementation of JobQueue, which is a Computational Grid-wide queuing system, or metaqueuing system, implemented in Legion. JobQueue is unique because of its ability to span multiple administrative domains. It can also be reconfigured dynamically along a number of dimensions and in the general case does not require special privileges to create, facilitating new …

Time-Domain Electric-Field Integral Equation With Central Finite Difference, Baek Ho Jung, Tapan Kumar Sarkar

Electrical Engineering and Computer Science - All Scholarship

In this paper, we present a new formulation using the time-domain electric-field integral equation (TD-EFIE) to obtain a transient scattering response from arbitrarily shaped conducting bodies. The time derivative of the magnetic vector potential is approximated with a central finite difference, and the scalar potential is time averaged by dividing it into two terms. This approach with an implicit method using central-difference results in accurate and stable transient scattering responses from conducting objects. Detailed mathematical steps are included, and several numerical results are presented.

A "Converse" Of The Banach Contraction Mapping Theorem, Pascal Hitzler, Anthony K. Seda

Computer Science and Engineering Faculty Publications

We prove a type of converse of the Banach contraction mapping theorem for metric spaces: if X is a T₁ topological space and f: X -> X is a function with the unique fixed point a such that fⁿ(x) converges to a for each x is a member of X, then there exists a distance function d on X such that f is a contraction on the complete ultrametric space (X,d) with contractivity factor 1/2. We explore properties of the resulting space (X,d).

Generalized Metrics And Topology In Logic Programming Semantics, Pascal Hitzler

Computer Science and Engineering Faculty Publications

Many fixed-point theorems are essentially topological in nature. Among them are the Banach contraction mapping theorem on metric spaces and the fixed-point theorem for Scott-continuous mappings on complete partial orders. The latter theorem is fundamental in denotational semantics since semantic operators in most programming language paradigms satisfy its requirements. The use of negation in logic programming and non-monotonic reasoning, however, renders some semantic operators to be non-monotonic, hence discontinuous with respect to the Scott topology, and therefore invalidates the standard approach, so that alternative methods have to be sought. In this thesis, we investigate topological methods, including generalized metric fixed-point …

Evolution Of Topology In Axi-Symmetric And 3-D Viscous Flows, Gerik Scheuermann, W. Kollmann, Xavier Tricoche, Thomas Wischgoll

Computer Science and Engineering Faculty Publications

No abstract provided.

Ambiguity-Directed Sampling For Qualitative Analysis Of Sparse Data From Spatially-Distributed Physical Systems, Chris Bailey-Kellogg, Naren Ramakrishnan

Computer Science Technical Reports

A number of important scientific and engineering applications, such as fluid dynamics simulation and aircraft design, require analysis of spatially-distributed data from expensive experiments and complex simulations. In such data-scarce applications, it is advantageous to use models of given sparse data to identify promising regions for additional data collection. This paper presents a principled mechanism for applying domain-specific knowledge to design focused sampling strategies. In particular, our approach uses ambiguities identified in a multi-level qualitative analysis of sparse data to guide iterative data collection. Two case studies demonstrate that this approach leads to highly effective sampling decisions that are also …

Parallel Detection Of Closed Streamlines In Planar Flows, Thomas Wischgoll, Gerik Scheuermann, Hans Hagen

Computer Science and Engineering Faculty Publications

No abstract provided.

Unique Supported-Model Classes Of Logic Programs, Pascal Hitzler, Anthony K. Seda

Computer Science and Engineering Faculty Publications

We study classes of programs, herein called unique supported-model classes, with the property that each program in the class has a unique supported model. Elsewhere, the authors examined these classes from the point of view of operators defined relative to certain three-valued logics. In this paper, we complement our earlier results by considering how unique supported-model classes fit into the framework given by various classes of programs in several well-known approaches to semantics.

Kontraktionssatze Auf Verallgemeinerten Metrischen Raumen, Pascal Hitzler

Computer Science and Engineering Faculty Publications

Guidelines For Development Of Courses For Delivery Over The Iowa Communications Network, Gary F. Hasman

CCE Theses and Dissertations

This paper examines the quality of education as it relates to the Iowa Communications Network (ICN). It reviews the literature to determine a working definition of quality that was used to create a list of characteristics desirable in teachers who use technology. A list of such teachers was solicited from three administrative committees of the ICN and from the directors of the state's 15 area education agencies. Four teachers were selected from the list and their approach to creating programs for delivery over the ICN was examined. Personal interviews were used to discover commonalities among the four teachers' approaches to …

Computer Graphics Optique: Optical Superposition Of Projected Computer Graphics, Aditi Majumder

Link Foundation Modeling, Simulation and Training Fellowship Reports

We present some ideas and demonstrations for a hybrid projector-based rendering and display technique we call Computer Graphics Optique. Instead of partially overlapping projected images to achieve a wide-area display, we completely overlap projected images on top of each other to achieve the addition of light and color in an "optical composition buffer''. The idea is to use the optical composition to replace some analytical computation, to increase rendering speed, gain flexibility, intensity range, and intensity resolution. Where projector-based displays are appropriate, potential uses include the optical realization of certain effects normally requiring a digital accumulation buffer, the optical composition …

Form Invariance And Implicit Parallelism, Michael D. Vose, Alden H. Wright

Computer Science Faculty Publications

Holland’s schema theorem (an inequality) may be viewed as an attempt to understand genetic search in terms of a coarse graining of the state space. Stephens and Waelbroeck developed that perspective, sharpening the schema theorem to an equality. Of particular interest is a “form invariance” of their equations; the form is unchanged by the degree of coarse graining. This paper establishes a similar form invariance for the more general model of Vose et al. and uses the attendant machinery as a springboard for an interpretation and discussion of implicit parallelism.

Bookmark Search: A Web-Based Bookmark Search Engine, Yun Sang Lee

Theses Digitization Project

The objective of the project is to create a search engine in which the databases of links are the bookmarks uploaded by the user. The main idea of the BOOKMARK-SEARCH system is the sharing of bookmarks resources required carrying on an Internet search. It aims to provide an affordable search solution to users while sharing bookmarks resouces.

Application Of Active Rules To Support Database Integrity Constraints And View Management, Suwanna Visavapattamawon

Theses Digitization Project

The project demonstrates the enforcement of integrity constraints in both the conventional and active database systems. The project implements a more complex user-defined constraint, a complicated view and more detailed database auditing on the active database system.

Lock-Free Scheduling Of Logical Processes In Parallel Simulation, Xiaowen Liu, David M. Nicol, King Tan Dartmouth College

Computer Science Technical Reports

With fixed lookahead information in a simulation model, the overhead of asynchronous conservative parallel simulation lies in the mechanism used for propagating time updates in order for logical processes to safely advance their local simulation clocks. Studies have shown that a good scheduling algorithm should preferentially schedule processes containing events on the critical path. This paper introduces a lock-free algorithm for scheduling logical processes in conservative parallel discrete-event simulation on shared-memory multiprocessor machines. The algorithm uses fetch\&add operations that help avoid inefficiencies associated with using locks. The lock-free algorithm is robust. Experiments show that, compared with the scheduling algorithm using …