Digital Commons Network^™

The Determination Of Natural Frequencies Of Rectangular Plates With Mixed Boundary Conditions By Discrete Singular Convolution, G. W. Wei, Yibao Zhao, Y. Xiang

Research Collection Lee Kong Chian School Of Business

This paper introduces the discrete singular convolution algorithm for vibration analysis of rectangular plates with mixed boundary conditions. A unified scheme is proposed for the treatment of simply supported, clamped and transversely supported (with nonuniform elastic rotational restraint) boundary conditions. The robustness and reliability of the present approach are tested by a number of numerical experiments. All results agree well with those in the literature.

Autoconfiguration, Registration And Mobility Management For Pervasive Computing, Archan Misra, Subir Das, Anthony Mcauley, Sajal K. Das

Research Collection School Of Computing and Information Systems

In the vision of pervasive computing, users will exchange information and control their environments from anywhere using various wireline/wireless networks and computing devices. We believe that current protocols, such as DHCP, PPP, and Mobile IP, must be enhanced to support pervasive network access. In particular, this article identifies three fundamental functions: autoconfiguration, registration, and mobility management, that need such enhancements. Realizing that the IP autoconfiguration capabilities must be extended to configure routers and large dynamic networks, we first describe our autoconfiguration solution based on the dynamic configuration and distribution protocol (DCDP). Second, we discuss why providing user-specific services over a …

A Method For Fast Revocation Of Public Key Certificates And Security Capabilities, D. Boneh, Xuhua Ding, Gene Tsudik, Chi Ming Wong

Research Collection School Of Computing and Information Systems

We present a new approach to fast certificate revocation centered around the concept of an on-line semi-trusted mediator (SEM). The use of a SEM in conjunction with a simple threshold variant of the RSA cryptosystem (mediated RSA) offers a number of practical advantages over current revocation techniques. Our approach simplifies validation of digital signatures and enables certificate revocation within legacy systems. It also provides immediate revocation of all security capabilities. This paper discusses both the architecture and implementation of our approach as well as performance and compatibility with the existing infrastructure. Our results show that threshold cryptography is practical for …

Representation Of Gyromagnetic Composite Media For Fdtd Modeling, Marina Koledintseva, James L. Drewniak, Xiaoning Ye

Electrical and Computer Engineering Faculty Research & Creative Works

A composite media containing particles with a high internal field of magnetic anisotropy (hexagonal ferrites) useful for numerous EMC applications in a wide frequency band is considered. Effective constitutive parameters of a high-loss composite gyromagnetic media are represented in the Lorentzian form. It is convenient for the numerical analysis using the finite-difference time-domain (FDTD) algorithm with a recursive convolution procedure. The equations for the electric and magnetic field updating in such media are represented.

Life Annuities Under Random Rates Of Interest., Lesley J. Baker

Electronic Theses and Dissertations

We begin by examining the accumulated value functions of some annuities-certain. We then investigate the accumulated value of these annuities where the interest is a random variable under some restrictions. Calculations are derived for the expected value and the variance of these accumulated values and present values. In particular we will examine an annuity-due of k yearly payments of 1. Then we will consider an increasing annuity-due of k yearly payments of 1, 2, ⋯ , k. And finally, we examine a decreasing annuity-due of k yearly payments of n, n - 1, ⋯ , n - k …

Simulation Of Engineering Systems Described By High-Index Dae And Discontinuous Ode Using Single Step Methods, Marc Compere

Publications

This dissertation presents numerical methods for solving two classes of or-dinary diferential equations (ODE) based on single-step integration meth-ods. The first class of equations addressed describes the mechanical dynamics of constrained multibody systems. These equations are ordinary differential equations (ODE) subject to algebraic constraints. Accordinly they are called differential-algebraic equations (DAE).

Specific contributions made in this area include an explicit transforma-tion between the Hessenberg index-3 form for constrained mechanical systems to a canonical state-space form used in the nonlinear control communities. A hybrid solution method was developed that incorporates both sliding-mode control (SMC) from the controls literature and post-stabilization from …

07/31/2001 - Richards Completes Advanced Training.Pdf, University Marketing And Communications

2001

No abstract provided.

2001 (January-June) Performance And Progress Report: Unh/Noaa Joint Hydrographic Center, Larry A. Mayer, Noaa-Unh Joint Hydrographic Center (Jhc/Ccom)

Progress Reports

Report Period: 01/01/2001 – 07/01/2001

The Geochemistry Of Banded Iron Formations In The Sukumaland Greenstone Belt Of Geita, Northern Tanzania: Evidence For Mixing Of Hydrothermal And Clastic Sources Of The Chemical Elements, M A H Maboko

Tanzania Journal of Science

Major and trace element compositions of samples of Banded Iron Formations (BIF) from the Neoarchaean Sukumaland Greenstone Belt of Geita in northern Tanzania reveal that the BIF precipitated from hydrothermal solutions. Fe-Ti-Al-Mn systematics suggest that the hydrothermal deposits have been contaminated, by up to 20% by weight, with detrital material having a composition similar to modern deep-sea pelagic clays. SiO2 and Fe2O3 contents are 48.2 to 88.5% and 8.9 to 49.1% respectively. Al2O3 contents lie between 0.33 and 2.1% and show no correlation with either Fe2O3 or SiO2. Al2O3 is, however, positively correlated with Ti, Ga, Hf, Rb,Th, Zr and …

Physicochemical Characteristics Of Some Locally Manufactured Edible Vegetable Oils Marketed In Dar Es Salaam, F N Ngassapa, O C Othman

Tanzania Journal of Science

The physicochemical properties (refractive index, saponification value, Free Fatty Acid (FFA) value, iodine value, acid value, peroxide value and tocopherol content) of seven edible vegetable oils manufactured in Tanzania, were assessed using standard procedures of the Association of Official Analytical Chemists (AOAC). Also determined were the levels of these properties with respect to shelf storage of the products. When compared with standard values recommended by the Codex Alimentarius Commission of FAO/WHO and with other published results, the locally produced vegetable oils were found to be of fair quality but of poor storage stability.

Comparison Of Direct Return And Birth-Death Return Receivers, H N Kundaeli

Tanzania Journal of Science

The performance of frame synchronized communication systems is governed largely by the design chosen for the receiver. Some systems employ a structure in which the receiver returns directly to the sync phase when a valid marker is encountered while in the loss verify state. These have been greatly studied. In some systems, the return path in the loss verify phase is implemented as a birth-death process. These systems have not received much attention. In this report, a receiver which employs a birth-death like structure in the loss path is investigated. Expressions for the performance parameters are derived and compared with …

Test Of The Additive-Dominance Model Of Grain Weight And Grain Uniformity Of Oat, Avena Sativa L, Genotypes, Sowm Reuben

Tanzania Journal of Science

An investigation of the genetic mechanisms controlling grain weights for the primary and secondary grains uniformity expressed in primary: secondary individual grain weight (P: S IGW) ratio and % tertiary grains produced was conducted using a backcross experiment'. Two oat, parental genotypes, I.L82-1657 (pistillate) and 10589 Cn (staminate) with different grain weight characteristics were hybridized to obtain 6 backcross generations viz. P1, P2, F1, B1, B2 and F2. The scaling test indicated that overall average, primary and secondary individual grain weights and % tertiary grain weight produced failed to satisfy the additive - dominance model and digenic interactions were detected …

Production Of Biogas From Water Hyacinth: Effect Of Subtrate Concentration, Particle Size And Incubation Period, J H Y Katima

Tanzania Journal of Science

A study was conducted, at constant temperature, to determine the effect of substrate concentration, particle size and incubation time on biogas production from water hyacinth. Substrate concentration was varied between 5-30 g/l of water, particle size between <1 mm - 3 mm and incubation period between 1-6 days. The maximum methane prodction of 72.53% v/v at substrate concentration of 25 g/1 and particle size less than 1 mm for water hyacinth shoots was achieved after five days of incubation. However, for the whole water hyacinth plant, methane content was 65.67% v/v at the same conditions.

The Meaning Of An Information-Centric Computer Environment, Jens G. Pohl

Collaborative Agent Design (CAD) Research Center

It is often lamented that we human beings are suffering from an information overload. This is a myth, as shown in Fig.1 there is no information overload. Instead we are suffering from a data overload. The confusion between data and information is not readily apparent and requires further explanation. Unorganized data are voluminous but of very little value. Over the past 15 years, industry and commerce have made significant efforts to rearrange this unorganized data into purposeful data, utilizing various kinds of database management systems. However, even in this organized form, we are still dealing with data and not information.

University Of Nevada, Las Vegas Advanced Accelerator Applications University Participation Program: Quarterly Report First Quarter (March-May 2001), Anthony Hechanova

Transmutation Research Program Reports (TRP)

This Quarterly Report is a primary deliverable from the University of Nevada, Las Vegas (UNLV) Advanced Accelerator Applications (AAA) University Participation Program (UPP) director to the U.S. Department of Energy Office of Nuclear Energy, Science and Technology (DOE-NE) as defined in the UNLV AAA Proposal.

The foundation of the UNLV AAA University Participation Program started as a grassroots effort in the late 1990s among community members and local, state, and federal representatives to encourage research and development of technical alternatives to direct disposal of used nuclear fuel which had been targeted since the early 1980s for Yucca Mountain, Nevada. A …

Comment On "Observation Of Superluminal Behaviors In Wave Propagation", Harry Ringermacher, Lawrence R. Mead

Faculty Publications

No abstract provided.

Electromagnetics, David V. Arnold, Richard H. Selfridge, Karl F. Warnick

Faculty Publications

Many applications of electrical engineering require a knowledge of the behavior of voltages and currents in electronic devices and within conductors. In many other situations it is not enough to understand the behavior the voltages and currents in just the conductors and other components, but also the influence of the voltage and current on surrounding materials.

Genesis And Evolution Of Proterozoic Crustal Boundaries In The Southern Rocky Mountains., Colin Arthur Shaw

Earth and Planetary Sciences ETDs

The lithosphere of the southwestern United States is a mosaic of Proterozoic arc terranes assembled to the southern margin of the Archean Wyoming craton between 1.8 and 1.6 Ga. This mosaic was profoundly transformed by ca. 1.4 Ga intracontinental plutonism, metamorphism, and tectonism. These processes of assembly and tectonic reactivation during the early stages of continental evolution laid the foundation for the development of the continental architecture of the southwestern United States.

This dissertation comprises three independent studies focused on different aspects of the Proterozoic evolution of tectonic boundaries exposed in the Southern Rocky Mountains. The first study is a …

Deafdigest Gold: Vol. 5, No. 52 July 29, 2001, Barry Strassler

DeafDigest Gold 2001

No abstract provided.

43rd Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 43rd annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-sponsored by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Denver, Colorado, July 29 - August 2, 2001.

2001 Summer Commencement, Harding University

Commencement Programs

Program for the Commencement on July 28.

Commencement Speaker: Daryl Bassett

Volume 38, Number 42: July 27, 2001, University Of North Dakota

University Letter Archive

No abstract provided.

Nocturnal Bird-Avoidance Modeling With Mobile-Marine Radar, Edward J. Zakrajsek, John A. Bissonette

Bird Strike Committee-USA/Canada Joint Annual Meeting: 3rd (2001)

To develop a bird-avoidance model for Naval Air Facility El Centro, California, we used a modified marine-radar system to quantify nocturnal (sunset to midnight) bird movements in the area. Previous birdradar studies relied on visual monitoring of the radar screen for data collection. This study represents the first use of computer-aided image analysis of marine-radar bird-data. Radar images were automatically captured, analyzed, and archived with a personal computer. The image analysis eliminated ground clutter, calculated the sample area, identified bird targets, and categorized them into three relative size classes. This made data collection more uniform by eliminating observer bias. We …

The Murray Ledger And Times, July 27, 2001, The Murray Ledger And Times

The Murray Ledger & Times

No abstract provided.

Volume 38, Number 42: July 27, 2001, University Of North Dakota

University Letter Archive

No abstract provided.

New Approaches For Sampling And Modeling Native And Exotic Plant Species Richness, Geneva W. Chong, Robin M. Reich, Mohammed A. Kalkhan, Thomas J. Stohlgren

Western North American Naturalist

We demonstrate new multi-phase, multi-scale approaches for sampling and modeling native and exotic plant species to predict the spread of invasive species and aid in control efforts. Our test site is a 54,000-ha portion of Rocky Mountain National Park, Colorado, USA. This work is based on previous research wherein we developed vegetation sampling techniques to identify hot spots of diversity, important rare habitats, and locations of invasive plant species. Here we demonstrate statistical modeling tools to rapidly assess current patterns of native and exotic plant species to determine which habitats are most vulnerable to invasion by exotic species. We use …

Status And Conservation Of Salmonids In Relation To Hydrologic Integrity In The Greater Yellowstone Ecosystem, Robert W. Van Kirk, Lyn Benjamin

Western North American Naturalist

Native salmonid status was evaluated with an index quantifying distribution and abundance of cutthroat trout (Oncorhynchus clarki) and grayling (Thymallus arcticus) in 41 watersheds comprising the Greater Yellowstone Ecosystem. We assessed hydrologic integrity with a percentile-based index measuring cumulative effects of reservoirs, surface water withdrawals, and consumptive water use. Status of native salmonids was poor in 70% of the watersheds; exceptions occurred in a north-south core extending from the Upper Yellowstone southward through the national parks to Bear Lake. Hydrologic integrity was highest in headwater areas and lowest in lower-elevation watersheds. Status of native and nonnative …

Summer Mustang, July 26, 2001

Cal Poly Student Newspaper

Student newspaper of California Polytechnic State University, San Luis Obispo, CA.

Understanding "Poor" Performance: Palmetto Achievement Challenge Test (Pact) Scores And Poverty, 2001 July 25, H. Gregory Hawkins

Publications

No abstract provided.

Predicting The Effects Of Dimensional And Material Property Variations In Micro Compliant Mechanisms, Jonathan W. Wittwer

Theses and Dissertations

Surface micromachining of micro-electro-mechanical systems (MEMS), like all other fabrication processes, has inherent variation that leads to uncertain material and dimensional parameters. To obtain accurate and reliable predictions of mechanism behavior, the effects of these variations need to be analyzed. This thesis expands already existing tolerance and uncertainty analysis methods to apply to micro compliant mechanisms. For simple compliant members, explicit equations can be used in uncertainty analysis. However, for a nonlinear implicit system of equations, the direct linearization method may be used to obtain sensitivities of output parameters to small changes in known variables. This is done by including …