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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
121

NET-CENTRIFYING THE GOULD TA6000 OSCILLOGRAPH

Guadiana, Juan, Benitez, Jesus, Tiqui, Dwight 10 1900 (has links)
ITC/USA 2007 Conference Proceedings / The Forty-Third Annual International Telemetering Conference and Technical Exhibition / October 22-25, 2007 / Riviera Hotel & Convention Center, Las Vegas, Nevada / Migrating analog architectures and equipments to network architectures is underway all across the globe. There is no doubt, a modern instrument must fit the network environment or simply will not be procured. Yet, funding constraints temper wholesale changes to net-centric technologies. The last analog stronghold in our data center is the oscillograph. Over 50 Gould TA 6000 Oscillographs reside at White Sands Missile Range. These are digital implementations of analog recorders, hence require analog signaling. Digital telemetry data (most common format) must be converted to analog to drive an oscillograph that converts analog back to digital to plot the data. The oscillograph’s interface board may be “hacked” by removing the Analog to Digital Converter (ADC) gaining direct access to the digital signal path. This idea was worth attempting as the prospect of replacing that many recorders with the newer network driven oscillographs is costly hence remote. This paper’s topic is the conversion of the hardware and a discussion on software issues. Though not pretty, it does preserve the large recorder investment for the time being. Issues with analog signaling, such as noise, drift and ground loops are gone. A commercial ethernet to digital adapter drives the new digital interface and transforms the recorder into an net-centric instrument.
122

Telemetry Chart Recording Via Direct Digital Link

Smith, Grant M., Alexander, James H. 10 1900 (has links)
International Telemetering Conference Proceedings / October 17-20, 1988 / Riviera Hotel, Las Vegas, Nevada / Mission safety and cost-efficiency concerns have resulted in a resurgence of interest in real-time strip chart recorders. But conventional recorder technologies require inordinate maintenance and daily calibration. Attempts at strip chart emulation involving costly dedicated microcomputers and CRT's have failed, because the chart itself is not real-time, a basic requirement. The concept of an inexpensive, direct digital link to a telemetry processing computer (VAX, e.g.) is discussed. A thorough examination of real-time monitoring of critical, non-repeatable data is presented. Objectives: An automated, turn-key telemetry data system. Reduce the routine maintenance required by conventional recording systems; eliminate the need for digital-to-analog converters (DAC's); and improve the efficiency of range personnel and the integrity of recorded data.
123

Spline finite strip method in the study of plates and shells with special reference to bridges

區達光, Au, Tat-kwong, Francis. January 1994 (has links)
published_or_final_version / Civil and Structural Engineering / Doctoral / Doctor of Philosophy
124

Spline finite strip analysis of arbitrarily shaped plates and shells

李華煜, Li, Wah-yuk. January 1988 (has links)
published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy
125

Nonlinear static and dynamic analysis of plates & shells by spline finite strip method

朱達善, Zhu, Dashan. January 1988 (has links)
published_or_final_version / Civil Engineering / Doctoral / Doctor of Philosophy
126

A hydrogeologic study of an unstable open-pit slope, Miami, Gila County, Arizona.

Earl, Thomas Alexander,1941- January 1973 (has links)
An unstable slope in an open-pit copper mine in Arizona was analyzed after a 250,000-ton slope failure had occurred. Data on all available time-dependent hydrogeologic factors were analyzed utilizing multiple regression techniques in order to build a mathematical model of the slide displacement. This allowed determination of those factors which were most influential in promoting instability. It was determined that a ground-water rise of approximately one foot, and rainfall in the week prior to the failure, were the most important factors contributing to this particular slide. This is believed to be due primarily to an increase in cleft-water, or hydrostatic, pressure, with seepage forces contributing a significant but relatively constant shear component. Because instability was observed to extend beyond the original slope failure, a dewatering analysis was undertaken. A steady-state finite element flow system model series was developed by progressively incorporating subsurface information, as well as water table location. The ground-water flow system within the granitic host rock was then simulated as a continuum, and a flow net derived. Analysis of this flow net, combined with known ground-water discharge into the open pit, comprised the basis to estimate the coefficient of permeability to be approximately 4 gallons/day/foot². This value was then utilized in a preliminary dewatering analysis incorporating standard aquifer equations to predict possible drawdowns. The computed drawdowns suggest that pumping rates on the order of 10 gallons/minute/well from a line of 12 wells spaced 50 feet apart would produce approximately 100 feet of drawdown after 1 year of pumping. Results of stability analyses for various ground-water levels indicated that when the water table is lowered by dewatering, a steeper slope could be maintained in the open pit. Such steepening could be as much as 1° when the water table is lowered one-half to one-quarter the height of the slope (135 feet), and approximately 4½° when the slope area is completely drained.
127

Simulation of hydrologic processes for surface mined lands

Fischer, John N. January 1976 (has links)
Natural factors limit the extent to which land disturbed by man's activities such as the strip mining of coal may be returned to productivity. In the western United States, the availability of water is frequently the most important of these factors. To assist decision makers in land restoration efforts, a procedure is developed by which precipitation and the distribution of precipitation water on reclaimed areas may be forecast. With this information, reclamation decisions can be made with increased confidence. The initial phase of the procedure is the development of a sequence-based stochastic precipitation model which provides as output simulated sequences of annual precipitation events. Probability distributions for storm parameters such as precipitation per event, event duration, distribution of events in time, etc. are obtained from analysis of historic climatological data for the study area. From these distributions simulated series of annual events possessing statistical characteristics of the actual event sequences are generated. Statistical analysis shows no significant differences between parameters of the actual events and those generated by the model. The stochastic precipitation model is used to drive a deterministic model simulating other hydrologic processes. In the second model, a finite difference solution records changes in water content within the soil profile. Root extraction, evaporation, infiltration and percolation are also simulated based upon changing hydraulic head at selected depth intervals. The kinematic wave approximation and the continuity of mass equation are used to route overland flow from the watershed. The model accurately predicts the distribution of water resulting from annual series of precipitation and potential evapotranspiration event sequences.
128

Yanawant: Paiute Places and Landscapes in the Arizona Strip Volume One of the Arizona Strip Landscapes and Place Name Study

Stoffle, Richard W., Van Vlack, Kathleen, Carroll, Alex, Chmara-Huff, Fletcher, Martinez, Aja January 2005 (has links)
This report is the product of a study funded by the Bureau of Land Management (BLM) entitled, The Arizona Strip Cultural Landscape and Place Name Study. The study has five main objectives: (1) to provide an overview of American Indian Cultural Landscapes and their relevance for federal agency practices, (2) to describe the ethnographic, historic, and cultural bases for Southern Paiute communities’ access to particular sites within the Arizona Strip, (3) to identify Southern Paiute place names, trails, and stories associated with selected cultural landscape sites within the Arizona Strip, (4) to include descriptions of the cultural significance of natural resources and physical environmental features at selected cultural landscape sites, and (5) to determine the need for future studies based on gaps identified in the historic and ethnographic record. The study is intended to serve as a foundation for identifying and managing Native American resources, cultural sites and cultural landscapes on the Arizona Strip. This report is focused on direct interviews with Southern Paiute people at places in the Arizona Strip. These locations were chosen to represent kinds of places that are culturally significant to Southern Paiute people. These include rock art sites, archaeology sites, springs, rivers, canyons, mountains, lava flows, and areas with special vistas. These places were chosen by representatives of the involved tribes, Arizona Strip BLM staff, and the project director at the Bureau of Applied Research in Anthropology at the University of Arizona. This is a first study of its kind funded by the Arizona Strip and so a study goal was to see what kinds of contemporary cultural importance would be assigned by Indian people to kinds of places. It was thus impossible to go to all places of cultural significance in the Arizona Strip so the study lays a foundation for more comprehensive studies in the future.
129

In situ testing of Gila Conglomerate with application to probabilistic slope stability

Kidd, David Alan, 1956- January 1989 (has links)
In this study the shear strength parameters for a consolidated, well-cemented boulder conglomerate at the Cyprus Miami Copper Mine are determined by a newly developed field test. The values obtained are used to investigate the probability of failure of pit slopes cut into the conglomerate. Any boulder conglomerate is impossible to test accurately with conventional laboratory techniques due to its large particle sizes and the destruction of cementation by conventional sampling methods. For these reasons a simple in situ test was developed which could be used in conjunction with laboratory techniques and analytical procedures to estimate the in situ strength properties of the Gila Conglomerate. The variability in the testing of the shear strength parameters of Gila Conglomerate make a probabilistic approach to design appropriate.
130

Fisher Information in X-ray/Gamma-ray Imaging Instrumentation Design

Salcin, Esen, Salcin, Esen January 2015 (has links)
Signal formation in a photon-counting x-ray/gamma-ray imaging detector is a complex process resulting in detector signals governed by multiple random effects. Recovering maximum possible information about event attributes of interest requires a systematic collection of calibration data and analysis provided by estimation theory. In this context, a likelihood model provides a description of the connection between the observed signals and the event attributes. A quantitative measure of how well the measured signals can be used to produce an estimate of the parameters is given by Fisher Information analysis. In this work, we demonstrate several applications of the Fisher Information Matrix (FIM) as a powerful and practical tool for investigating and optimizing potential next-generation x-ray/gamma-ray detector designs, with an emphasis on medical-imaging applications. Using FIM as a design tool means to explore the physical detector design choices that have a relationship with the FIM through the likelihood function, how are they interrelated, and determining whether it is possible to modify any of these choices to yield or retain higher values for Fisher Information. We begin by testing these ideas by investigating a new type of a semiconductor detector, a Cadmium Telluride (CdTe) detector with double-sided-strip geometry developed by our collaborators at the Japan Aerospace Exploration Agency (JAXA). The statistical properties of the detector signals as a function of interaction positions in 3D (x, y, z) are presented with mathematical expressions as well as experimental data from measurements using synchrotron radiation at the Advanced Photon Source at Argonne National Laboratory. We show the computation of FIM for evaluating positioning performance and discuss how various detector parameters, that are identified to affect FIM, can be used in detector optimization. Next, we show the application of FIM analysis in a detector system based on multi-anode photomultiplier tubes coupled to a monolithic scintillator in the design of smart electronic read-out strategies. We conclude by arguing that a detector system is expected to perform the best when the hardware is optimized jointly with the estimation algorithm (simply referred to as the "software" in this context) that will be used with it. The results of this work lead to the idea of a detector development approach where the detector hardware platform is developed concurrently with the software and firmware in order to achieve optimal performance.

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