18,056 Matching Results

Search Results

Advanced search parameters have been applied.

A Fundamental Study of the Mechanism by Which Hydrogen Enters Metals During Chemical and Electrochemical Processing

Description: Note presenting several known methods of controlling the entry and exit of hydrogen in steel as correlated with the known chemical behavior of atomic and molecular hydrogen. Some of the results of testing and a newly proposed mechanism for hydrogen control are provided.
Date: April 1952
Creator: McGraw, L. D.; Snavely, C. A.; Moore, H. L.; Woodberry, P. T. & Faust, C. L.
Partner: UNT Libraries Government Documents Department

Modern Techniques in Acoustical Signal and Image Processing

Description: Acoustical signal processing problems can lead to some complex and intricate techniques to extract the desired information from noisy, sometimes inadequate, measurements. The challenge is to formulate a meaningful strategy that is aimed at performing the processing required even in the face of uncertainties. This strategy can be as simple as a transformation of the measured data to another domain for analysis or as complex as embedding a full-scale propagation model into the processor. The aims of both approaches are the same--to extract the desired information and reject the extraneous, that is, develop a signal processing scheme to achieve this goal. In this paper, we briefly discuss this underlying philosophy from a ''bottom-up'' approach enabling the problem to dictate the solution rather than visa-versa.
Date: April 4, 2002
Creator: Candy, J V
Partner: UNT Libraries Government Documents Department

Hydrogenation of Petroleum and Lignite Tar Distillates

Description: Report issued by the U.S. Bureau of Mines regarding the operation of the Coal Hydrogenation Demonstration Plant in Missouri. This report summarizes the operating experience gained and the characteristics of the products created during operation of the plant. The report includes graphs, tables, and illustrations.
Date: April 1950
Creator: Clarke, E. A.; Chaffee, C. C. & Hirst, L. L.
Partner: UNT Libraries Government Documents Department

MPX: software for multiplexing hardware performance counters in multithreaded programs

Description: Hardware performance counters are CPU registers that count data loads and stores, cache misses, and other events. Counter data can help programmers understand software performance. Although CPUs typically have multiple counters, each can monitor only one type of event at a time, and some counters can monitor only certain events. Therefore, some CPUs cannot concurrently monitor interesting combinations of events. Software multiplexing partly overcomes this limitation by using time sharing to monitor multiple events on one counter: However; counter multiplexing is harder to implement for multithreaded programs than for single-threaded ones because of certain difficulties in managing the length of the time slices. This paper describes a software library called MPX that overcomes these difficulties. MPX allows applications to gather hardware counter data concurrently for any combination of countable events. MPX data are typically within a few percent of counts recorded without multiplexing.
Date: January 8, 2001
Creator: May, J M
Partner: UNT Libraries Government Documents Department

An Inquiry into the Inevitability of Prediction Error in Investment Portfolio Models

Description: Many mathematical programming models of the selection of investment portfolios assume that the best portfolio at any given level of risk is the portfolio having the highest level of return. The expected level of return is defined as a linear combination of the expected returns of the individual investments contained within the portfolio,and risk is defined in terms of variance of return. This study uses Monte Carlo simulation to establish that if the estimates of the future returns on potential investments are unbiased, the steady-state return on the portfolio is overestimated by the procedure used in the standard models. Under reasonable assumptions concerning the parameters of the estimates of the various returns, this bias is quite sizeable, with the steady-state predicted return often overestimating the steady-state actual return by more than ten percentage points. In addition, it is shown that when the variances of the alternative potential investments are not all equal,a limitation on the variance of the portfolio will reduce the magnitude of the bias. In many reasonable cases, constraining the portfolio variance reduces the bias by a magnitude greater than the amount by which it reduces the predicted portfolio return, causing the steady-state actual return to rise. This implies that return cannot automatically be assumed to be a monotonic function of risk.
Date: December 1972
Creator: Valentine, Jerome Lynn
Partner: UNT Libraries

COMPARISON OF GASEOUS WASTE HANDLING SYSTEMS FOR PL-3

Description: Gaseous waste handling systems are compared for direct and indirect boiling water and pressurized water reactors for PL-3 application. Areas that are common to the various concepts are not discussed since they do not enter into a comparison study. The major differences present are in the handling of active gases released to or held in the primary system coolant. These gases which could be present, their possibIe release from the system, and the necessary processing requirements are discussed in detail. Sufficient information is presented to enable one to analyze the methcds required to remove gaseous activity present in other size and type pressurized and boiIing water reactors. (auth)
Date: February 28, 1962
Creator: Noble, J.H. & Duke, E.E.
Partner: UNT Libraries Government Documents Department

Scientific Workstation Evaluation Project: Multidisciplinary Experience with a Scientific Workstation

Description: This document is a formal report on the scientific workstation evaluation project. The objective of this project has been to evaluate a scientific workstation. When new computing systems appeared that exhibited the capabilities necessary to do scientific computing work at relatively low equipment cost, both the staff of the Argonne scientific divisions and we (the Computing Services staff) wished to know more about the equipment and the vendor claims.
Date: December 1984
Creator: Raffenetti, Richard C.; Carruthers, Clifford M.; Birgersson, Goran; Blomquist, R. N.; Kennedy, James M.; Koelling, Dale D. et al.
Partner: UNT Libraries Government Documents Department

A word processing curriculum model for post-secondary educational institutions

Description: The subject of this study is a curricular model in word processing for post-secondary programs of business education. The study had the following purposes: to survey the present emphasis upon word processing in programs of business education; to survey the current use of word processing in business; to identify the characteristic form of word processing systems; to survey the need for qualified personnel for employment in word processing; to evaluate current educational practices in educating individuals for positions in word processing; and to utilize findings from both business and education to construct a curricular model for post-secondary educational institutions.
Date: December 1978
Creator: Gillard, Sharlett Kay Wolfe
Partner: UNT Libraries

A fast contour descriptor algorithm for supernova imageclassification

Description: We describe a fast contour descriptor algorithm and its application to a distributed supernova detection system (the Nearby Supernova Factory) that processes 600,000 candidate objects in 80 GB of image data per night. Our shape-detection algorithm reduced the number of false positives generated by the supernova search pipeline by 41% while producing no measurable impact on running time. Fourier descriptors are an established method of numerically describing the shapes of object contours, but transform-based techniques are ordinarily avoided in this type of application due to their computational cost. We devised a fast contour descriptor implementation for supernova candidates that meets the tight processing budget of the application. Using the lowest-order descriptors (F{sub 1} and F{sub -1}) and the total variance in the contour, we obtain one feature representing the eccentricity of the object and another denoting its irregularity. Because the number of Fourier terms to be calculated is fixed and small, the algorithm runs in linear time, rather than the O(n log n) time of an FFT. Constraints on object size allow further optimizations so that the total cost of producing the required contour descriptors is about 4n addition/subtraction operations, where n is the length of the contour.
Date: July 16, 2006
Creator: Aragon, Cecilia R. & Aragon, David Bradburn
Partner: UNT Libraries Government Documents Department

Topic Modeling on Historical Newspapers

Description: Paper for the 2011 ACL Workshop on Language Technology for Cultural Heritage, Social Sciences, and Humanities. This paper discusses topic modeling on historical newspaper.
Date: June 2011
Creator: Yang, Tze-I; Torget, Andrew J., 1978- & Mihalcea, Rada, 1974-
Partner: UNT College of Arts and Sciences

A Programming Language For Concurrent Processing

Description: This thesis is a proposed solution to the problem of including an effective interrupt mechanism in the set of concurrent- processing primitives of a block-structured programming language or system. The proposed solution is presented in the form of a programming language definition and model. The language is called TRIPLE.
Date: August 1972
Creator: Jackson, Portia M.
Partner: UNT Libraries

Research and Development in the Computer and Information Sciences: [Part] 2. Processing, Storage, and Output Requirements in Information Processing Systems: A Selective Literature Review

Description: From Introduction: "This is the second in a series of reports concerned with research and development requirements and areas of continuing concern in the computer and information sciences and technologies."
Date: May 1970
Creator: Stevens, Mary Elizabeth
Partner: UNT Libraries Government Documents Department