Author: Truong X. Nguyen
Publisher:
ISBN:
Category : Anechoic chambers
Languages : en
Pages : 24
Book Description
This paper describes the implementation of mode-stirred method for susceptibility testing according to the current DO-160D standard. Test results on an Engine Data Processor using the implemented procedure and the comparisons with the standard anechoic test results are presented. The comparison experimentally shows that the susceptibility thresholds found in mode-stirred method are consistently higher than anechoic. This is consistent with the recent statistical analysis finding by NIST that the current calibration procedure overstates field strength by a fixed amount. Once the test results are adjusted for this value, the comparisons with the anechoic results are excellent. The results also show that etst method has excellent chamber to chamber repeatability. Several areas for improvements to the current procedure are also identiified and implemented.
Mode-stirred Method Implementation for HIRF Susceptibility Testing and Results Comparison with Anechoic Method
Author: Truong X. Nguyen
Publisher:
ISBN:
Category : Anechoic chambers
Languages : en
Pages : 24
Book Description
This paper describes the implementation of mode-stirred method for susceptibility testing according to the current DO-160D standard. Test results on an Engine Data Processor using the implemented procedure and the comparisons with the standard anechoic test results are presented. The comparison experimentally shows that the susceptibility thresholds found in mode-stirred method are consistently higher than anechoic. This is consistent with the recent statistical analysis finding by NIST that the current calibration procedure overstates field strength by a fixed amount. Once the test results are adjusted for this value, the comparisons with the anechoic results are excellent. The results also show that etst method has excellent chamber to chamber repeatability. Several areas for improvements to the current procedure are also identiified and implemented.
Publisher:
ISBN:
Category : Anechoic chambers
Languages : en
Pages : 24
Book Description
This paper describes the implementation of mode-stirred method for susceptibility testing according to the current DO-160D standard. Test results on an Engine Data Processor using the implemented procedure and the comparisons with the standard anechoic test results are presented. The comparison experimentally shows that the susceptibility thresholds found in mode-stirred method are consistently higher than anechoic. This is consistent with the recent statistical analysis finding by NIST that the current calibration procedure overstates field strength by a fixed amount. Once the test results are adjusted for this value, the comparisons with the anechoic results are excellent. The results also show that etst method has excellent chamber to chamber repeatability. Several areas for improvements to the current procedure are also identiified and implemented.
An Ablation Technique for Enhancing Reentry Antenna Performance; Flight Test Results
Author: Dallas T. Hayes
Publisher:
ISBN:
Category : Ablation (Aerothermodynamics)
Languages : en
Pages : 84
Book Description
To develop alternative solutions to Air Force problems relating to signal transmission in the presence of ionization, AFCRL undertook an extensive investigation of techniques for modifying reentry plasmas. The program included laboratory tests and a series of reentry flight experiments. This report describes the flight test of one successful technique, Teflon ablation, a passive approach that requires no internal support systems. A reentry vehicle fitted with a Teflon-coated nosecap was instrumented to measure antenna impedance mismatch, interantenna coupling, signal attenuation, and charged-particle density. The probe data showed that the local boundary-layer electron density decreased by as much as a factor of 200. The Teflon coating effected a 25-dB decrease in S-band signal attenuation. High-power antenna breakdown was modified by the presence of the ablation products. Details of the vehicle design, flight dynamics, and ablation, are presented, and the results of the Teflon-ablation technique are contrasted with those of a successful liquid-injection technique that was tested on a previous flight.
Publisher:
ISBN:
Category : Ablation (Aerothermodynamics)
Languages : en
Pages : 84
Book Description
To develop alternative solutions to Air Force problems relating to signal transmission in the presence of ionization, AFCRL undertook an extensive investigation of techniques for modifying reentry plasmas. The program included laboratory tests and a series of reentry flight experiments. This report describes the flight test of one successful technique, Teflon ablation, a passive approach that requires no internal support systems. A reentry vehicle fitted with a Teflon-coated nosecap was instrumented to measure antenna impedance mismatch, interantenna coupling, signal attenuation, and charged-particle density. The probe data showed that the local boundary-layer electron density decreased by as much as a factor of 200. The Teflon coating effected a 25-dB decrease in S-band signal attenuation. High-power antenna breakdown was modified by the presence of the ablation products. Details of the vehicle design, flight dynamics, and ablation, are presented, and the results of the Teflon-ablation technique are contrasted with those of a successful liquid-injection technique that was tested on a previous flight.
Survey Questions
Author: Jean M. Converse
Publisher: SAGE
ISBN: 9780803927438
Category : Social Science
Languages : en
Pages : 84
Book Description
This text reviews the literature on crafting survey instruments, and provides both general principles governing question-writing and guidance on how to develop a questionnaire.
Publisher: SAGE
ISBN: 9780803927438
Category : Social Science
Languages : en
Pages : 84
Book Description
This text reviews the literature on crafting survey instruments, and provides both general principles governing question-writing and guidance on how to develop a questionnaire.
The Electrical Journal
Author:
Publisher:
ISBN:
Category : Electric engineering
Languages : en
Pages : 1298
Book Description
Publisher:
ISBN:
Category : Electric engineering
Languages : en
Pages : 1298
Book Description
Standard Forms for Specifications, Tests, Reports, and Methods of Sampling for Road Materials
Author:
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 824
Book Description
Publisher:
ISBN:
Category : Agriculture
Languages : en
Pages : 824
Book Description
Fatigue Testing and Analysis of Results
Author: W. Weibull
Publisher: Elsevier
ISBN: 1483154165
Category : Technology & Engineering
Languages : en
Pages : 322
Book Description
Fatigue Testing and Analysis of Results discusses fundamental concepts of fatigue testing and results analysis. The book begins with a description of the symbols and nomenclature selected for the present book, mainly those proposed by the ASTM Committee E-9 on Fatigue. Fatigue testing methods are then discussed including routine tests, short-life and long-life tests, cumulative-damage tests, and abbreviated and accelerated tests. Separate chapters cover fatigue testing machines and equipment; instruments and measuring devices; and test pieces used in fatigue testing. The factors affecting test results are considered, including material, types of stressing, test machine, environment, and testing technique. The final two chapters cover the planning of test programs and the presentation of results. Test program planning involves the statistical design of a test series; specification and sampling of test pieces; and choice of test pieces, testing machines, and test conditions. The chief purpose of most fatigue tests is the experimental determination of the relation between the endurance and the magnitude of the applied stress range for the material and the specimen under consideration, and final results can be condensed into a table, graph, or analytical expression.
Publisher: Elsevier
ISBN: 1483154165
Category : Technology & Engineering
Languages : en
Pages : 322
Book Description
Fatigue Testing and Analysis of Results discusses fundamental concepts of fatigue testing and results analysis. The book begins with a description of the symbols and nomenclature selected for the present book, mainly those proposed by the ASTM Committee E-9 on Fatigue. Fatigue testing methods are then discussed including routine tests, short-life and long-life tests, cumulative-damage tests, and abbreviated and accelerated tests. Separate chapters cover fatigue testing machines and equipment; instruments and measuring devices; and test pieces used in fatigue testing. The factors affecting test results are considered, including material, types of stressing, test machine, environment, and testing technique. The final two chapters cover the planning of test programs and the presentation of results. Test program planning involves the statistical design of a test series; specification and sampling of test pieces; and choice of test pieces, testing machines, and test conditions. The chief purpose of most fatigue tests is the experimental determination of the relation between the endurance and the magnitude of the applied stress range for the material and the specimen under consideration, and final results can be condensed into a table, graph, or analytical expression.
Compression of an array of similar crash test simulation results
Author: Stefan Peter Müller
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832554440
Category : Mathematics
Languages : en
Pages : 232
Book Description
Big data thrives on extracting knowledge from a large number of data sets. But how is an application possible when a single data set is several gigabytes in size? The innovative data compression techniques from the field of machine learning and modeling using Bayesian networks, which have been theoretically developed and practically implemented here, can reduce these huge amounts of data to a manageable size. By eliminating redundancies in location, time, and between simulation results, data reductions to less than 1% of the original size are possible. The developed method represents a promising approach whose use goes far beyond the application example of crash test simulations chosen here.
Publisher: Logos Verlag Berlin GmbH
ISBN: 3832554440
Category : Mathematics
Languages : en
Pages : 232
Book Description
Big data thrives on extracting knowledge from a large number of data sets. But how is an application possible when a single data set is several gigabytes in size? The innovative data compression techniques from the field of machine learning and modeling using Bayesian networks, which have been theoretically developed and practically implemented here, can reduce these huge amounts of data to a manageable size. By eliminating redundancies in location, time, and between simulation results, data reductions to less than 1% of the original size are possible. The developed method represents a promising approach whose use goes far beyond the application example of crash test simulations chosen here.
Encyclopedia of Research Design
Author: Neil J. Salkind
Publisher: SAGE
ISBN: 1412961270
Category : Philosophy
Languages : en
Pages : 1779
Book Description
"Comprising more than 500 entries, the Encyclopedia of Research Design explains how to make decisions about research design, undertake research projects in an ethical manner, interpret and draw valid inferences from data, and evaluate experiment design strategies and results. Two additional features carry this encyclopedia far above other works in the field: bibliographic entries devoted to significant articles in the history of research design and reviews of contemporary tools, such as software and statistical procedures, used to analyze results. It covers the spectrum of research design strategies, from material presented in introductory classes to topics necessary in graduate research; it addresses cross- and multidisciplinary research needs, with many examples drawn from the social and behavioral sciences, neurosciences, and biomedical and life sciences; it provides summaries of advantages and disadvantages of often-used strategies; and it uses hundreds of sample tables, figures, and equations based on real-life cases."--Publisher's description.
Publisher: SAGE
ISBN: 1412961270
Category : Philosophy
Languages : en
Pages : 1779
Book Description
"Comprising more than 500 entries, the Encyclopedia of Research Design explains how to make decisions about research design, undertake research projects in an ethical manner, interpret and draw valid inferences from data, and evaluate experiment design strategies and results. Two additional features carry this encyclopedia far above other works in the field: bibliographic entries devoted to significant articles in the history of research design and reviews of contemporary tools, such as software and statistical procedures, used to analyze results. It covers the spectrum of research design strategies, from material presented in introductory classes to topics necessary in graduate research; it addresses cross- and multidisciplinary research needs, with many examples drawn from the social and behavioral sciences, neurosciences, and biomedical and life sciences; it provides summaries of advantages and disadvantages of often-used strategies; and it uses hundreds of sample tables, figures, and equations based on real-life cases."--Publisher's description.
Instrumented Impact Testing of Plastics and Composite Materials
Author: Sandra L. Kessler
Publisher: ASTM International
ISBN: 0803109377
Category : Composite materials
Languages : en
Pages : 384
Book Description
Publisher: ASTM International
ISBN: 0803109377
Category : Composite materials
Languages : en
Pages : 384
Book Description
An Investigation of Tests of Iowa Shale Drain Tile
Author: William Japhia Schlick
Publisher:
ISBN:
Category : Drain-tiles
Languages : en
Pages : 76
Book Description
Publisher:
ISBN:
Category : Drain-tiles
Languages : en
Pages : 76
Book Description