I n the present work, the gaseous and liquid decomposition products of 50 mass% hydroxylamine=wat... more I n the present work, the gaseous and liquid decomposition products of 50 mass% hydroxylamine=water solution were measured for samples subsequent to a thermally induced runaway reaction. The noncondensable gas phase composition was approximately 70 mol% N 2 , 24 mol% N 2 O, 4 mol% NO, and 2 mol% H 2 , and ammonia was detected in the liquid residue. Based on analysis of the gas phase decomposition products, the following overall decomposition reaction (summation of several series and parallel reaction mechanisms taking place during the experiment) was determined: 157NH 2 OH liq ¡! 61NH 3gas ‡ 35N 2gas ‡ 12N 2 O gas ‡ 2NO gas ‡ 143H 2 O gas ‡ H 2gas This reaction has an associated theoretical standard heat of reaction of ¡124 kJ mol ¡1 (¡29:6 kcal mol ¡1), which is consistent with ¡117 kJ mol ¡1 (¡28 kcal mol ¡1) estimated for the hydroxylamine overall heat of decomposition reported previously.
Journal of Loss Prevention in the Process Industries, 2002
Organic heat transfer fluids (HTFs) are widely used because of their low vapor pressures and wide... more Organic heat transfer fluids (HTFs) are widely used because of their low vapor pressures and wide ranges of working temperatures. It is a common misconception that operations involving HTFs below their flash point temperatures do not represent a hazard, but aerosols of combustible liquids at temperatures below their flashpoints have been recognized for their potential to cause fires and explosions. The hazard is further exacerbated by the paucity of experimental information about the formation and behavior of aerosols from HTF releases. This article presents droplet sizes, spray development, and aerosol formation distances for an alkylated aromatic HTF aerosol generated mechanically by means of a leak from a pressurized container into ambient air as functions of HTF temperature, pressure, and orifice size. A Malvern Laser Diffraction Particle Analyzer was used to measure aerosol droplet sizes along the centerline of the liquid sprays, and high-speed photography was used for spray visualization and interpretation of stream atomization. Effects of pressure, temperature, and orifice diameter confirm critical Weber Number theory.
... However, this behavior may also be stimulatory; a quiver by the female may entice a male to f... more ... However, this behavior may also be stimulatory; a quiver by the female may entice a male to fertilize the eggs (Winn, 1958a) and a ... and criticisms; J. Fairbank for data collection and fish care; A. Moretz for technical assistance in writing computer code; and D. Christie and the ...
Proceedings 1992 IEEE International Conference on Computer Design: VLSI in Computers & Processors
... finding covers of products [2]-[4], by looking for parity-like patterns [4], or by modifying ... more ... finding covers of products [2]-[4], by looking for parity-like patterns [4], or by modifying a canonical form [5]. The GMX (Graphical Minimizer for XORS) algo-rithm described here works by "reading-off" and mini-mizing the solution from an augmented OBDD, called an SFG. ...
Proceedings. 'Meeting the Tests of Time'., International Test Conference
Test generation algorithms use search strategies to control decision making whenever the algorith... more Test generation algorithms use search strategies to control decision making whenever the algorithms encounter a choice of a signal value or action. The authors' study of traditional search strategies used in automatic test pattern generation (ATPG) has led to the observation that no single strategy is superior for all faults in a circuit or all circuits. Further experimentation led to
Proceedings of the 34th Annual Hawaii International Conference on System Sciences
The research pilot presented here studied six student groups (N=30) using a CyberCollaboratory to... more The research pilot presented here studied six student groups (N=30) using a CyberCollaboratory to perform the tasks necessary to complete a complex group project assignment in the asynchronous mode of communication. Each group was comprised of students from two major universities located over 500 miles apart and in different states. All students performed the task over a period of approximately four months. The task was comprised of subtask types, which can best be described using the model presented by Fjermestad, Hiltz and Turoff [7]. The group task required students to (1) generate, (2) choose, (3) negotiate, and (4) execute components for project performance. Preliminary findings of the study indicate that students can work productively and collaboratively in the asynchronous mode of communication, even at great distances, to produce exciting and valuable class projects given appropriate tools and process structures such as Group Decision Support Tools, Collaborative Document Production, Group Discussion (Computer Mediated Conferencing), E-mail, and Chat.
Fault simulation of VLSI circuits takes considerable computing resources and there have been sign... more Fault simulation of VLSI circuits takes considerable computing resources and there have been significant efforts to speed up the fault simulation process. This paper describes a distributed fault simulator implemented on a loosely-coupled network of general purpose computers. The techniques used result in a close to linear speedup and can be used effectively in most industrial VLSI CAD environments. * ?his work was supported by the Semiconductor Research Corporation under Contract 87-DP-109.
Submissions to the STB, including submissions to the supporting files (programs, datasets, and he... more Submissions to the STB, including submissions to the supporting files (programs, datasets, and help files), are on a nonexclusive, free-use basis. In particular, the author grants to StataCorp the nonexclusive right to copyright and distribute the material in accordance with the Copyright Statement below. The author also grants to StataCorp the right to freely use the ideas, including communication of the ideas to other parties, even if the material is never published in the STB. Submissions should be addressed to the Editor. Submission guidelines can be obtained from either the editor or StataCorp. Copyright Statement. The Stata Technical Bulletin (STB) and the contents of the supporting files (programs, datasets, and help files) are copyright c by StataCorp. The contents of the supporting files (programs, datasets, and help files), may be copied or reproduced by any means whatsoever, in whole or in part, as long as any copy or reproduction includes attribution to both (1) the author and (2) the STB. The insertions appearing in the STB may be copied or reproduced as printed copies, in whole or in part, as long as any copy or reproduction includes attribution to both (1) the author and (2) the STB. Written permission must be obtained from Stata Corporation if you wish to make electronic copies of the insertions. Users of any of the software, ideas, data, or other materials published in the STB or the supporting files understand that such use is made without warranty of any kind, either by the STB, the author, or Stata Corporation. In particular, there is no warranty of fitness of purpose or merchantability, nor for special, incidental, or consequential damages such as loss of profits. The purpose of the STB is to promote free communication among Stata users.
Transportation Research Record: Journal of the Transportation Research Board, 1999
The relationship between physical and mental fatigue is not well understood or well documented, a... more The relationship between physical and mental fatigue is not well understood or well documented, a lapse that affects understanding of the interaction between loading and unloading activities and safe operation in the trucking industry. This experiment addresses the effects of loading and unloading on driving performance by measuring driving impairment in volunteer truck drivers operating a truck-driving simulator. Ten drivers participated, each for 17 days, including 2 driving weeks of 5 days with 14-h duty cycles separated by two 58-h rest periods. During one of the driving weeks, participants were given a significant hand-loading task, 3 hours of hand-loading pallets of boxes on 3 of 5 days; during the remaining week, only driving tasks were scheduled. Performance measurement focused on driver responses to planned and unplanned crash-likely challenges and vigilance tasks, supported by simulator-mediated driving indicators, such as lane-keeping performance. Measures of subjective d...
Theoretical and mathematical issues related to the study of interaction effects are discussed. Co... more Theoretical and mathematical issues related to the study of interaction effects are discussed. Constraints imposed by the theoretical expectation of ordinal or monotone interactions are defined by the general concept of inversion values. The mathematical constraints implied by these values are demonstrated by the derivation of a general formula. Further definitions related to this general formula are discussed for qualitative and quantitative variables. It is argued that interaction effects of substantial magnitude may not be routinely detected in behavioral science because many interactive theories may be implicitly ordinal. Levels of predictability common to behavioral science make such effects mathematically nonexistent, and thus impossible to detect. To have strong ordinal moderation, there must be a strong effect to be moderated.
Coefficient alpha is a widely used and useful index of reliability, but it provides an inappropri... more Coefficient alpha is a widely used and useful index of reliability, but it provides an inappropriate estimate of reliability when used with multidimensional composites. The problematic nature of this inappropriate usage varies primarily as a function of the prominence of distinct factors in a composite and to a lesser extent as a function of the length of the measure. Implications for use of coefficient alpha estimates of reliability as the basis for correcting observed correlations for unreliability are described for a variety of levels of multidimensionality and measure length. Researchers should correct for unreliability to estimate construct interrelationships but must exercise care as to how they conceptualize errors of measurement and how they estimate reliability.
The First Emancipation, The Abolition of Slavery in the North. By Arthur Zilversmit. The Universi... more The First Emancipation, The Abolition of Slavery in the North. By Arthur Zilversmit. The University of Chicago Press: Chicago and London. 1967. $6.95.The Secret City: A History of Race Relations in the Nation's Capital. By Constance McLaughlin Green. Princeton: Princeton University Press. 1967. 389 pp. $8.50.Railroad Labor Disputes. The Beginnings of Federal Strike Policy. By Gerald G. Eggert. Ann Arbor:
Test generation algorithms contain search strategies which are used to control decision making wh... more Test generation algorithms contain search strategies which are used to control decision making when the algorithm encounters a choice of signal value, or what action to perform next. Our study of traditional search strategies used in automatic test pattern generation has led us to the observation that no single strategy is superior for all faults in a circuit and all circuits. Further experimentation led to the conclusion that a combination of search strategies provides better fault coverage and/or faster ATPG for a given backtrack limit. Instead of using just one strategy up to the backtrack limit, a primary strategy is used for the first half of the backtrack limit, then a secondary strategy is used for the second half of the backtrack limit. This article presents a qualitative ATPG cost model based on the number of test generation events, uses this model to explain why search strategy switching is faster, and shows experimental evidence to verify both the cost model and search strategy switching theory. The experiments were performed with the ISCAS circuits and our implementation of the FAN algorithm.
The effects of number of predictors, predictor intercorrelations, validity, and level of subgroup... more The effects of number of predictors, predictor intercorrelations, validity, and level of subgroup difference on composite validity, adverse impact ratios, and mean subgroup difference associated with various predictor composites, including and excluding a ' 'high impact'' ability measure, were assessed. The size of subgroup differences is substantially smaller when low-impact predictors are combined with a high-impact predictor, but hiring ratios for majority and minority groups still indicate a prima facie case of discrimination, using the fourth-fifths rule for most predictor-criterion combinations. However, the validity of a composite of alternate predictors and cognitive ability may exceed the validity of cognitive ability alone and reduce the size of subgroup differences.
International Journal of Behavioral Development, 1998
This paper discusses methods to model the concept of synergy at the level of manifest categorical... more This paper discusses methods to model the concept of synergy at the level of manifest categorical variables. First, a classification of concepts of synergy is presented. A dditive and nonadditive concepts of synergy are distinguished. Most prominent among the nonadditive concepts is superadditive synergy. Examples are given from the natural sciences and the social sciences. M delling focuses on the relationship between the agents involved in a synergetic process. These relationships are expressed in form of contrasts, expressed in effect coding vectors in design matrices for nonstandard log-linear models. A method by Schuster is used to transform design matrices such that parameters reflect the proposed relationships. A n example reanalyses data presented by Bishop, Fienberg, and Holland (1975) that describe the development of thromboembolisms in women who differ in their patterns of contraceptive use and smoking. Alternative methods of analysis are com pared. Implications for devel...
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 1993
A cost model and implementation of a hierarchical test generation technique are presented in this... more A cost model and implementation of a hierarchical test generation technique are presented in this paper. The cost model is based on fundamental test generation activities such as implication, justification, and backtracking. The model shows that the cost of hierarchical test generation grows as G log G under some realistic assumptions, while the cost of gatelevel test generation may grow as fast as G2, where G is the number of gates in a circuit under test. This implies hierarchical test generators should be much faster than flat test generators on large circuits. The implementation of the hierarchical test generation is fan-out-oriented, and uses a minimal hierarchical representation of the circuit and functional level heuristics to perform implication, propagation, and backtracing with high-level functional models. Experiments with three hierarchically described circuits show hierarchical test generation is 1.5 to 8.9 times faster than flat gate-level generation.
IEEE International Conference on Computer-Aided Design, 1989
FANHAT, has been designed and implemented to accelerate test generation for digital circuits. FAN... more FANHAT, has been designed and implemented to accelerate test generation for digital circuits. FANHAT uses a minimal hierarchical representation of the circuit and functional level heuristics to perform implication, propagation, and backtracking with high-level functional model. Experiments with three circuits show hierarchical test generation using FANHAT is 1.5 to 8.9 times faster than flat gate-level test generation
I n the present work, the gaseous and liquid decomposition products of 50 mass% hydroxylamine=wat... more I n the present work, the gaseous and liquid decomposition products of 50 mass% hydroxylamine=water solution were measured for samples subsequent to a thermally induced runaway reaction. The noncondensable gas phase composition was approximately 70 mol% N 2 , 24 mol% N 2 O, 4 mol% NO, and 2 mol% H 2 , and ammonia was detected in the liquid residue. Based on analysis of the gas phase decomposition products, the following overall decomposition reaction (summation of several series and parallel reaction mechanisms taking place during the experiment) was determined: 157NH 2 OH liq ¡! 61NH 3gas ‡ 35N 2gas ‡ 12N 2 O gas ‡ 2NO gas ‡ 143H 2 O gas ‡ H 2gas This reaction has an associated theoretical standard heat of reaction of ¡124 kJ mol ¡1 (¡29:6 kcal mol ¡1), which is consistent with ¡117 kJ mol ¡1 (¡28 kcal mol ¡1) estimated for the hydroxylamine overall heat of decomposition reported previously.
Journal of Loss Prevention in the Process Industries, 2002
Organic heat transfer fluids (HTFs) are widely used because of their low vapor pressures and wide... more Organic heat transfer fluids (HTFs) are widely used because of their low vapor pressures and wide ranges of working temperatures. It is a common misconception that operations involving HTFs below their flash point temperatures do not represent a hazard, but aerosols of combustible liquids at temperatures below their flashpoints have been recognized for their potential to cause fires and explosions. The hazard is further exacerbated by the paucity of experimental information about the formation and behavior of aerosols from HTF releases. This article presents droplet sizes, spray development, and aerosol formation distances for an alkylated aromatic HTF aerosol generated mechanically by means of a leak from a pressurized container into ambient air as functions of HTF temperature, pressure, and orifice size. A Malvern Laser Diffraction Particle Analyzer was used to measure aerosol droplet sizes along the centerline of the liquid sprays, and high-speed photography was used for spray visualization and interpretation of stream atomization. Effects of pressure, temperature, and orifice diameter confirm critical Weber Number theory.
... However, this behavior may also be stimulatory; a quiver by the female may entice a male to f... more ... However, this behavior may also be stimulatory; a quiver by the female may entice a male to fertilize the eggs (Winn, 1958a) and a ... and criticisms; J. Fairbank for data collection and fish care; A. Moretz for technical assistance in writing computer code; and D. Christie and the ...
Proceedings 1992 IEEE International Conference on Computer Design: VLSI in Computers & Processors
... finding covers of products [2]-[4], by looking for parity-like patterns [4], or by modifying ... more ... finding covers of products [2]-[4], by looking for parity-like patterns [4], or by modifying a canonical form [5]. The GMX (Graphical Minimizer for XORS) algo-rithm described here works by "reading-off" and mini-mizing the solution from an augmented OBDD, called an SFG. ...
Proceedings. 'Meeting the Tests of Time'., International Test Conference
Test generation algorithms use search strategies to control decision making whenever the algorith... more Test generation algorithms use search strategies to control decision making whenever the algorithms encounter a choice of a signal value or action. The authors' study of traditional search strategies used in automatic test pattern generation (ATPG) has led to the observation that no single strategy is superior for all faults in a circuit or all circuits. Further experimentation led to
Proceedings of the 34th Annual Hawaii International Conference on System Sciences
The research pilot presented here studied six student groups (N=30) using a CyberCollaboratory to... more The research pilot presented here studied six student groups (N=30) using a CyberCollaboratory to perform the tasks necessary to complete a complex group project assignment in the asynchronous mode of communication. Each group was comprised of students from two major universities located over 500 miles apart and in different states. All students performed the task over a period of approximately four months. The task was comprised of subtask types, which can best be described using the model presented by Fjermestad, Hiltz and Turoff [7]. The group task required students to (1) generate, (2) choose, (3) negotiate, and (4) execute components for project performance. Preliminary findings of the study indicate that students can work productively and collaboratively in the asynchronous mode of communication, even at great distances, to produce exciting and valuable class projects given appropriate tools and process structures such as Group Decision Support Tools, Collaborative Document Production, Group Discussion (Computer Mediated Conferencing), E-mail, and Chat.
Fault simulation of VLSI circuits takes considerable computing resources and there have been sign... more Fault simulation of VLSI circuits takes considerable computing resources and there have been significant efforts to speed up the fault simulation process. This paper describes a distributed fault simulator implemented on a loosely-coupled network of general purpose computers. The techniques used result in a close to linear speedup and can be used effectively in most industrial VLSI CAD environments. * ?his work was supported by the Semiconductor Research Corporation under Contract 87-DP-109.
Submissions to the STB, including submissions to the supporting files (programs, datasets, and he... more Submissions to the STB, including submissions to the supporting files (programs, datasets, and help files), are on a nonexclusive, free-use basis. In particular, the author grants to StataCorp the nonexclusive right to copyright and distribute the material in accordance with the Copyright Statement below. The author also grants to StataCorp the right to freely use the ideas, including communication of the ideas to other parties, even if the material is never published in the STB. Submissions should be addressed to the Editor. Submission guidelines can be obtained from either the editor or StataCorp. Copyright Statement. The Stata Technical Bulletin (STB) and the contents of the supporting files (programs, datasets, and help files) are copyright c by StataCorp. The contents of the supporting files (programs, datasets, and help files), may be copied or reproduced by any means whatsoever, in whole or in part, as long as any copy or reproduction includes attribution to both (1) the author and (2) the STB. The insertions appearing in the STB may be copied or reproduced as printed copies, in whole or in part, as long as any copy or reproduction includes attribution to both (1) the author and (2) the STB. Written permission must be obtained from Stata Corporation if you wish to make electronic copies of the insertions. Users of any of the software, ideas, data, or other materials published in the STB or the supporting files understand that such use is made without warranty of any kind, either by the STB, the author, or Stata Corporation. In particular, there is no warranty of fitness of purpose or merchantability, nor for special, incidental, or consequential damages such as loss of profits. The purpose of the STB is to promote free communication among Stata users.
Transportation Research Record: Journal of the Transportation Research Board, 1999
The relationship between physical and mental fatigue is not well understood or well documented, a... more The relationship between physical and mental fatigue is not well understood or well documented, a lapse that affects understanding of the interaction between loading and unloading activities and safe operation in the trucking industry. This experiment addresses the effects of loading and unloading on driving performance by measuring driving impairment in volunteer truck drivers operating a truck-driving simulator. Ten drivers participated, each for 17 days, including 2 driving weeks of 5 days with 14-h duty cycles separated by two 58-h rest periods. During one of the driving weeks, participants were given a significant hand-loading task, 3 hours of hand-loading pallets of boxes on 3 of 5 days; during the remaining week, only driving tasks were scheduled. Performance measurement focused on driver responses to planned and unplanned crash-likely challenges and vigilance tasks, supported by simulator-mediated driving indicators, such as lane-keeping performance. Measures of subjective d...
Theoretical and mathematical issues related to the study of interaction effects are discussed. Co... more Theoretical and mathematical issues related to the study of interaction effects are discussed. Constraints imposed by the theoretical expectation of ordinal or monotone interactions are defined by the general concept of inversion values. The mathematical constraints implied by these values are demonstrated by the derivation of a general formula. Further definitions related to this general formula are discussed for qualitative and quantitative variables. It is argued that interaction effects of substantial magnitude may not be routinely detected in behavioral science because many interactive theories may be implicitly ordinal. Levels of predictability common to behavioral science make such effects mathematically nonexistent, and thus impossible to detect. To have strong ordinal moderation, there must be a strong effect to be moderated.
Coefficient alpha is a widely used and useful index of reliability, but it provides an inappropri... more Coefficient alpha is a widely used and useful index of reliability, but it provides an inappropriate estimate of reliability when used with multidimensional composites. The problematic nature of this inappropriate usage varies primarily as a function of the prominence of distinct factors in a composite and to a lesser extent as a function of the length of the measure. Implications for use of coefficient alpha estimates of reliability as the basis for correcting observed correlations for unreliability are described for a variety of levels of multidimensionality and measure length. Researchers should correct for unreliability to estimate construct interrelationships but must exercise care as to how they conceptualize errors of measurement and how they estimate reliability.
The First Emancipation, The Abolition of Slavery in the North. By Arthur Zilversmit. The Universi... more The First Emancipation, The Abolition of Slavery in the North. By Arthur Zilversmit. The University of Chicago Press: Chicago and London. 1967. $6.95.The Secret City: A History of Race Relations in the Nation's Capital. By Constance McLaughlin Green. Princeton: Princeton University Press. 1967. 389 pp. $8.50.Railroad Labor Disputes. The Beginnings of Federal Strike Policy. By Gerald G. Eggert. Ann Arbor:
Test generation algorithms contain search strategies which are used to control decision making wh... more Test generation algorithms contain search strategies which are used to control decision making when the algorithm encounters a choice of signal value, or what action to perform next. Our study of traditional search strategies used in automatic test pattern generation has led us to the observation that no single strategy is superior for all faults in a circuit and all circuits. Further experimentation led to the conclusion that a combination of search strategies provides better fault coverage and/or faster ATPG for a given backtrack limit. Instead of using just one strategy up to the backtrack limit, a primary strategy is used for the first half of the backtrack limit, then a secondary strategy is used for the second half of the backtrack limit. This article presents a qualitative ATPG cost model based on the number of test generation events, uses this model to explain why search strategy switching is faster, and shows experimental evidence to verify both the cost model and search strategy switching theory. The experiments were performed with the ISCAS circuits and our implementation of the FAN algorithm.
The effects of number of predictors, predictor intercorrelations, validity, and level of subgroup... more The effects of number of predictors, predictor intercorrelations, validity, and level of subgroup difference on composite validity, adverse impact ratios, and mean subgroup difference associated with various predictor composites, including and excluding a ' 'high impact'' ability measure, were assessed. The size of subgroup differences is substantially smaller when low-impact predictors are combined with a high-impact predictor, but hiring ratios for majority and minority groups still indicate a prima facie case of discrimination, using the fourth-fifths rule for most predictor-criterion combinations. However, the validity of a composite of alternate predictors and cognitive ability may exceed the validity of cognitive ability alone and reduce the size of subgroup differences.
International Journal of Behavioral Development, 1998
This paper discusses methods to model the concept of synergy at the level of manifest categorical... more This paper discusses methods to model the concept of synergy at the level of manifest categorical variables. First, a classification of concepts of synergy is presented. A dditive and nonadditive concepts of synergy are distinguished. Most prominent among the nonadditive concepts is superadditive synergy. Examples are given from the natural sciences and the social sciences. M delling focuses on the relationship between the agents involved in a synergetic process. These relationships are expressed in form of contrasts, expressed in effect coding vectors in design matrices for nonstandard log-linear models. A method by Schuster is used to transform design matrices such that parameters reflect the proposed relationships. A n example reanalyses data presented by Bishop, Fienberg, and Holland (1975) that describe the development of thromboembolisms in women who differ in their patterns of contraceptive use and smoking. Alternative methods of analysis are com pared. Implications for devel...
IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems, 1993
A cost model and implementation of a hierarchical test generation technique are presented in this... more A cost model and implementation of a hierarchical test generation technique are presented in this paper. The cost model is based on fundamental test generation activities such as implication, justification, and backtracking. The model shows that the cost of hierarchical test generation grows as G log G under some realistic assumptions, while the cost of gatelevel test generation may grow as fast as G2, where G is the number of gates in a circuit under test. This implies hierarchical test generators should be much faster than flat test generators on large circuits. The implementation of the hierarchical test generation is fan-out-oriented, and uses a minimal hierarchical representation of the circuit and functional level heuristics to perform implication, propagation, and backtracing with high-level functional models. Experiments with three hierarchically described circuits show hierarchical test generation is 1.5 to 8.9 times faster than flat gate-level generation.
IEEE International Conference on Computer-Aided Design, 1989
FANHAT, has been designed and implemented to accelerate test generation for digital circuits. FAN... more FANHAT, has been designed and implemented to accelerate test generation for digital circuits. FANHAT uses a minimal hierarchical representation of the circuit and functional level heuristics to perform implication, propagation, and backtracking with high-level functional model. Experiments with three circuits show hierarchical test generation using FANHAT is 1.5 to 8.9 times faster than flat gate-level test generation
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Papers by William Rogers