Search Results

Resource Discovery Using Z39.50: Promise and Reality

Description: This paper discusses the Z39.50 protocol. The ANSI/NISO Z39.50 protocol for information retrieval addresses the complex challenges of intersystem communication. Original uses envisioned for the protocol look very little like current implementations and uses. In the 1980s, users on one library catalog system would search and retrieve bibliographic records on a remote system. By the late 1990s, there was a need for discovering networked resources and integrating access to them. Yet, the Z39.50 protocol has addressed both these scenarios. This paper provides a portrayal of Z39.50 that explains its flexibility in response to a variety of information retrieval requirements in the networked environment.
Date: November 2000
Creator: Moen, William E.
Partner: UNT College of Information

Organization of Long-Term Interstellar Distributed Digital Preservation Networks

Description: This presentation discusses the organization of long-term interstellar distributed digital preservation networks. Long term (centuries) management of large growing public bodies of information is both more and less understood. This presentation discusses what we can learn from current efforts to develop long term strategies for digital preservation.
Date: October 1, 2011
Creator: Halbert, Martin
Partner: UNT Libraries

Energy-Aware Time Synchronization in Wireless Sensor Networks

Description: I present a time synchronization algorithm for wireless sensor networks that aims to conserve sensor battery power. The proposed method creates a hierarchical tree by flooding the sensor network from a designated source point. It then uses a hybrid algorithm derived from the timing-sync protocol for sensor networks (TSPN) and the reference broadcast synchronization method (RBS) to periodically synchronize sensor clocks by minimizing energy consumption. In multi-hop ad-hoc networks, a depleted sensor will drop information from all other sensors that route data through it, decreasing the physical area being monitored by the network. The proposed method uses several techniques and thresholds to maintain network connectivity. A new root sensor is chosen when the current one's battery power decreases to a designated value. I implement this new synchronization technique using Matlab and show that it can provide significant power savings over both TPSN and RBS.
Date: December 2006
Creator: Saravanos, Yanos
Partner: UNT Libraries

A Guide to Distributed Digital Preservation

Description: This text is a collection of essays that gives an overview of the reasons for considering distributed digital preservation (a system which maintains copies of digital objects in multiple geographic locations) as well as considerations for implementing this kind of digital preservation. According to the back cover, "Readers may use this guide to gain both a philosophical and practical understanding of the emerging field of distributed digital preservation, including how to establish or join a network."
Date: 2010
Creator: MetaArchive Cooperative
Partner: UNT Libraries

A transaction costs explanation of inter-local government collaboration.

Description: This study develops a model of collaboration choice among city governments. The theoretical model suggests that collaboration is a function of transaction costs that vary with different institutional arrangements utilized in cities, as well as the degree of competition between cities. This study argues that cities facing high transaction costs and high competition are less likely to participate in collaboration and to participate less deeply. Underlying these environmental factors are resource factors that create incentives for cities to collaborate for efficiency gains, which affect both the decision to collaboration and the depth of collaboration. Eleven hypotheses are presented to explain why cities choose to participate in collaboration in the first stage of the analysis and how deeply they collaborate in the second stage. Utilizing a Heckman model of this two-stage process, I find broad support for a number of variables that measure each of these theoretical constructs.
Date: August 2005
Creator: Krueger, Eric L.
Partner: UNT Libraries

Throughput Optimization in Multi-Cell CDMA Networks

Description: In this paper, the authors investigate the performance of a multi-cell CDMA network by determining the maximum throughput that the network can archive for a given grade-of-service requirement, quality-of-service requirement, network topology and call arrival rate profile.
Date: March 2005
Creator: Akl, Robert G.; Naraghi-Pour, Mort & Hegde, Manju V.
Partner: UNT College of Engineering

Electrical stimulation of nerve cell networks growing on microelectrode arrays: stimulation efficiency and entrainment

Description: Presentation for the 2005 University Scholars Day at the University of North Texas discussing research on electrical stimulation of nerve cell networks growing on microelectrode arrays and stimulation efficiency and entrainment.
Date: March 31, 2005
Creator: Jain, Vivek & Gross, Guenter W.
Partner: UNT Honors College

A Non-equilibrium Approach to Scale Free Networks

Description: Many processes and systems in nature and society can be characterized as large numbers of discrete elements that are (usually non-uniformly) interrelated. These networks were long thought to be random, but in the late 1990s, Barabási and Albert found that an underlying structure did in fact exist in many natural and technological networks that are now referred to as scale free. Since then, researchers have gained a much deeper understanding of this particular form of complexity, largely by combining graph theory, statistical physics, and advances in computing technology. This dissertation focuses on out-of-equilibrium dynamic processes as they unfold on these complex networks. Diffusion in networks of non-interacting nodes is shown to be temporally complex, while equilibrium is represented by a stable state with Poissonian fluctuations. Scale free networks achieve equilibrium very quickly compared to regular networks, and the most efficient are those with the lowest inverse power law exponent. Temporally complex diffusion also occurs in networks with interacting nodes under a cooperative decision-making model. At a critical value of the cooperation parameter, the most efficient scale free network achieves consensus almost as quickly as the equivalent all-to-all network. This finding suggests that the ubiquity of scale free networks in nature is due to Zipf's principle of least effort. It also suggests that an efficient scale free network structure may be optimal for real networks that require high connectivity but are hampered by high link costs.
Date: August 2012
Creator: Hollingshad, Nicholas W.
Partner: UNT Libraries

Client/Server Systems Performance Evaluation Measures Use and Importance: a Multi-Site Case Study of Traditional Performance Measures Applied to the Client/Server Environment

Description: This study examines the role of traditional computing performance measures when used in a client/server system (C/SS) environment. It also evaluates the effectiveness of traditional computing measures of mainframe systems for use in C/SS. The underlying problem was the lack of knowledge about how performance measures are aligned with key business goals and strategies. This research study has identified and evaluated client/server performance measurements' importance in establishing an effective performance evaluation system. More specifically, this research enables an organization to do the following: (1) compare the relative states of development or importance of performance measures, (2) identify performance measures with the highest priority for future development, (3) contrast the views of different organizations regarding the current or desired states of development or relative importance of these performance measures.
Date: May 1999
Creator: Posey, Orlando Guy
Partner: UNT Libraries