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Design Considerations For High-Pressure Reciprocating Compressors For Refinery Services, S. N. Dwivedi

International Compressor Engineering Conference

No abstract provided.

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Performance Study Of A Prototype Reciprocating Piston Compressor With Special Attention To Valve Design And Gas Pulsation, J. Kim, W. Soedel

International Compressor Engineering Conference

No abstract provided.

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Development Of A Scroll-Type Oil-Free Vacuum Pump, T. Kushiro, K. Miyazaki, H. Kataoka, S. Nii, S. Machida

International Compressor Engineering Conference

No abstract provided.

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Mathematical Model Of Rotary Compressor To Simulate Its Transient Behavior, T. Yanagisawa, T. Shimizu, M. Fukuta, H. Suzuki

International Compressor Engineering Conference

No abstract provided.

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Hermetic Refrigerating Compressors And The Cfc Substitution, E. Heinzelmann, M. S. Ussyk

International Compressor Engineering Conference

No abstract provided.

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Tardis: A Numerical Simulation Package For Drive Systems, W. Suwanwisoot, C. M. Ong

Department of Electrical and Computer Engineering Technical Reports

TARDIS is a digital computer simulation package originally intended to simulate drive systems. Its versatility has proved to be very useful in other areas as well. It is designed to replace the functionality of analog computers so that the user who cannot afford to have one can use the program on a personal or mainframe computer. The author believes that it is one of the most efficient and accurate simulation programs of its kind at this point even though not all of its potential has been exploited to. the fullest. It can handle index 0 and 1 differential-algebraic systems with …

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Fish1d 2.2 User’S Manual, M. S. Lundstrom, M. A. Stettler, T. T. Herman, P. E. Dood

Department of Electrical and Computer Engineering Technical Reports

FISH1D is a computer program that solves the one-dimensional Poisson equation for electrostatic Fields in Semiconductor Heterostructures. The program will print or plot the electrostatic potential, electric field, electron and hole densities, dopant density, ionized dopant density, and other quantities of interest versus position at an applied bias voltage (assuming zero current). A capacitance or sheet carrier concentration versus voltage analysis may also be performed. While FISH1D was originally written for the ternary Alx Ga1 _xAs, it has been modified to simulate CdxHg1^xTe, ZnSe, GexSi1^ , and Si as well, and the program can be readily modified to analyze other …

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Local Epitaxial Overgrowth For Stacked Complementary Mos Transistor Pairs, R. P. Zingg, G. W. Neudeck, B. Hoefflinger

Department of Electrical and Computer Engineering Technical Reports

A three-dimensional silicon processing technology for CMOS circuits was developed and characterized. The first fully depleted SOI devices with individually biasable gates on both sides of the silicon film were realized. A vertically stacked CMOS Inverter built by lateral overgrowth was reported for the first time. Nucleation-free epitaxial lateral overgrowth of silicon over thin oxides was developed for both a pancake and a barrel-type epitaxy reactor: This process was optimized to limit damage to gate oxides and minimize dopant diffusion within the Substrate. Autodoping from impurities of the MOS transistors built in the substrate was greatly reduced. A planarisation technique …

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Automatic Parallelization Of Database Queries, Myong H. Kang, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

Although automatic parallelization of conventional language programs is now widely accepted, relatively little emphasis has been placed on automatic parallelization of database query programs (sometimes referred to as “multiple queries” ). In this paper, we discuss the unique problems associated with automatic parallelization of database programs. From this discussion, we derive a complete approach to automatic parallelization of database programs. Beside integrating a number of existing techniques, our approach relies heavily on several new concepts, including the concepts of “algorithm-level” analysis and hybrid static/dynamic scheduling.

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Image Segmentation Using Human Visual System Properties With Applications In Image Compression, Heidi A. Peterson, Sarah A. Rajala, Edward J. Delp

Department of Electrical and Computer Engineering Technical Reports

In order to represent a digital image, a very large number of bits is required. For example, a 512 X 512 pixel, 256 gray level image requires over two million bits. This large number of bits is a substantial drawback when it is necessary to store or transmit a digital image. Image compression, often referred to as image coding, attempts to reduce the number of bits used to represent an image, while keeping the degradation in the decoded image to a minimum. One approach to image compression is segmentation-based image compression. The image to be compressed is segmented, i.e. the …

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3-D Beamspace Ml Based Bearing Estimator Incorporating Frequency Diversity And Interference Cancellation, Ta-Sung Lee, Michael D. Zoltowski

Department of Electrical and Computer Engineering Technical Reports

The problem of low-angle radar tracking utilizing an array of antennas is considered. In the low-angle environment, echoes return from a low flying target via a specular path as well as a direct path. The problem is compounded by the fact that the two signals arrive within a beamwidth of each other and are usually fully correlated, or coherent. In addition, the SNR at each antenna element is typically low and only a small number of data samples, or snapshots, is available for processing due to the rapid movement of the target. Theoretical studies indicates that the Maximum Likelihood (ML) …

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Commonwealth's Choice: Results From The Massachusetts Public Opinion Survey, Barry Bluestone, Mary Ellen Colten, Thomas Ferguson

McCormack Graduate School General Publications (active until 2013)

From November 11 through December 4, 1989, the Center for Survey Research of the University of Massachusetts at Boston conducted a random digit dial survey of adults aged 18 and over in Massachusetts. A total of 423 individuals were interviewed in a sampling procedure that yielded a 63 percent response rate. In contrast to most media polls, this survey was carried out over a period of four weeks permitting extensive efforts at locating and interviewing difficult-to-reach, reluctant, or less interested respondents. This survey is likely to be more representative of the true population of Massachusetts than most state polls.

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A Comparison Of Refrigerant Constant Monitoring Leak Detectors, D. Mcclure, T. Anderson

International Refrigeration and Air Conditioning Conference

No abstract provided.

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The Cfc Problem, Report Of The Situation In France And Evolution, C. Brian

International Refrigeration and Air Conditioning Conference

No abstract provided.

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Heat Transfer Coefficient, Two-Phase Flow Boiling Of Hfc134a, K. Hambraeus

International Refrigeration and Air Conditioning Conference

No abstract provided.

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Compressor Technologies For R-22 Low Temperature Applications, T. Diab, J. Gephart

International Refrigeration and Air Conditioning Conference

No abstract provided.

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The R-134a Energy Efficiency Problem: Factor Fiction, N. Behrens, T. W. Dekleva, J. G. Hartley, F. T. Murphy, R. L. Powell

International Refrigeration and Air Conditioning Conference

No abstract provided.

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A Pressure Sensitive Mat For Measuring Contact Pressure Distributions Of Patients Lying On Hospital Beds, Charles F. Babbs, Joe D. Bourland, George P. Graber, James T. Jones, William E. Schoenlein

Weldon School of Biomedical Engineering Faculty Publications

The authors describe a novel system for sensing and displaying the distribution of contact pressure caused by a patient's lying on a hospital bed. The system includes a flexible, pressure sensitive mat, electronics to activate the mat, a small computer to process data, and a color video display. The present prototypes can sense pressure at 1,536 discrete locations in a rectangular grid of 24 x 64 nodes, each node representing an area of 4 cm2. The computer receives data from each node and displays the results as a false-color map, refreshable every 5 seconds. The pressure sensitive mat itself includes …

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Quantitation Of The Hydroxyl Radical By Reaction With Dimethyl Sulfoxide, Melissa G. Steiner, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This investigation was conducted to validate the use of dimethyl sulfoxide (DMSO) as a quantitative molecular probe for the generation of hydroxyl radicals (HO) in aqueous systems. Reaction of HO with DMSO produces methane sulfinic acid as a primary product, which can be detected by a simple calorimetric assay. To evaluate this method for estimating total HO production, we studied three model systems, including the Fenton reaction,  irradiation of water, and ultraviolet photolysis of hydrogen peroxide, for which the theoretical maximum yield of HO could be calculated and compared to measured DMSO oxidation. The results confirm that 0.05 to …

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Free Radicals And The Etiology Of Colon Cancer, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

This hypothesis paper reviews diverse evidence suggesting that intracolonic production of oxygen radicals may play a role in carcinogenesis. The hypothesis began to evolve when the author made the chance discovery that 1/10,000 dilutions of feces generated detectable quantities of highly reactive hydroxyl radicals (HO). The rate of HO formation, detected using DMSO as a molecular probe, was quite remarkable, corresponding to that which would be produced by over 10,000 rads of gamma irradiation per day, absorbed in the periphery of the fecal mass adjacent to the mucosa. The relatively high concentrations of iron in feces, together with the ability …

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Accuracy And Precision Of Computer-Simulated Tissue Temperatures In Individual Human Intracranial Tumours Treated With Interstitial Hyperthermia, J A. Deford, Charles F. Babbs, U H. Patel, N E. Fearnot, J A. Marchosky, C J. Moran

Weldon School of Biomedical Engineering Faculty Publications

Accurate knowledge of tissue temperature is necessary for effective delivery of clinical hyperthermia in the treatment of malignant tumours. This report compares computer-predicted versus measured intratumoral temperatures in 11 human subjects with intracranial tumours, treated with a conceptually simple 'conductive' interstitial hyperthermia system. Interstitial hyperthermia was achieved by the use of parallel arrays of implanted, electrically heated catheters. The tissue was warmed by thermal conduction and blood convection. Simulation of intratumoral temperatures was achieved by solving a modified bioheat transfer equation on a digital computer using a finite difference method. Comparison of intratumoral temperatures from simulations and measured values differed …

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Hardware Barrier Synchronization: Static Barrier Mimd (Sbm), Matthew T. O'Keefe, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

In this paper, we give the design, and performance analysis, of a new, highly efficient, synchronization mechanism called “Static Barrier MIMD” or “SBM.” Unlike traditional barrier synchronization, the proposed barriers are designed to facilitate the use of static (compile-time) code scheduling for eliminating some synchronizations. For this reason, our barrier hardware is more general than most hardware barrier mechanisms, allowing any subset of the processors to participate in each barrier. Since code scheduling typically operates on fine-grain parallelism, it is also vital that barriers be able to execute in a small number of clock ticks. The SBM is actually only …

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Surface Passivation Effects Of As2s3 Glass On Self‐Aligned Algaas/Gaas Heterojunction Bipolar Transistors, H. L. Chuang, M. S. Carpenter, Michael R. Melloch, Mark S. Lundstrom, E. Yablonovitch, T. J. Gmitter

Department of Electrical and Computer Engineering Faculty Publications

A recently developed As₂S₃ chemical treatment was used to passivate the perimeters of self‐aligned heterojunction bipolar transistors (HBTs). The As₂S₃chemical treatment significantly lowered the base current resulting in a two order of magnitude reduction in the collector current density at which dc current gain was observed (β=1). No degradation with time has been observed in the electrical characteristics of the chemically treated HBTs. This absence of degradation is attributed to the impermeability to oxygen of the As2S3 glass which coats the perimeter of the HBT after chemical treatment.

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Orientation-Dependent Perimeter Recombination In Gaas Diodes, T. B. Stellwag, Michael R. Melloch, Mark S. Lundstrom, M. S. Carpenter, R. F. Pierret

Department of Electrical and Computer Engineering Faculty Publications

Perimeter recombination currents affect the performance of GaAs-based devices such as solar cells, heterojunction bipolar transistors, and injection lasers. We report that the n SEf 2 perimeter recombination current has a strong orientation dependence. More than a factor of five variation in the surface recombination current at mesa-etched edges has been observed. These results suggest that with proper device design, perimeter recombination currents could be substantially reduced.

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Theoretical Basis For Controlling Minimal Tumor Temperature During Interstitial Conductive Heat Therapy, Charles F. Babbs, Neal E. Fearnot, J A. Marchosky, C J. Moran, James T. Jones, T D. Plantenga

Weldon School of Biomedical Engineering Faculty Publications

This paper describes simulation of steady-state intratumoral temperatures achieved by a simple modality of local heat therapy: interstitial treatment with parallel arrays of warmed, conductive heating elements. During “conductive heating” power is directly deposited only in the interstitial probes. Adjacent tissue is warmed by heat conduction. Simulations of interstitial conductive heating involved solution of the bioheat transfer equation on a digital computer using a finite difference model of the treated tissue. The simulations suggest that when the complete temperature distributions for conductive interstitial hyperthermia are examined in detail, substantial uniformity of the temperature distributions is evident. Except for a thin …

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Researches On A Cooler And Cleaner Compressor, Z. Jiang, D. Gao, Q. Hu

International Compressor Engineering Conference

No abstract provided.

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Mechanical Efficiency Of A Variable Speed Scroll Compressor, N. Ishii, M. Yamamura, S. Muramatsu, S. Yamamoto, M. Sakai

International Compressor Engineering Conference

No abstract provided.

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Hardware Barrier Synchronization: Static Barrier Mimd (Sbm), Matthew T. O'Keefe, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

In this paper, we give the design, and performance analysis, of a new, highly efficient, synchronization mechanism called “Static Barrier MIMD” or “SBM.” Unlike traditional barrier synchronization, the proposed barriers are designed to facilitate the use of static (compile-time) code scheduling for eliminating some synchronizations. For this reason, our barrier hardware is more general than most hardware barrier mechanisms, allowing any subset of the processors to participate in each barrier. Since code scheduling typically operates on fine-grain parallelism, it is also vital that barriers be able to execute in a small number of clock ticks. The SBM is actually only …

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Optimal Code Scheduling For Multiple-Pipeline Processors, Ashar Nisar, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

Pipelining the functional units and memory interface of processors can result in shorter cycle times and dramatic increases in performance, but only if the pipeline latency can be hidden by other useful operations. The portion of pipeline latency which is not hidden results in an extension of the total execution time, either implemented by hardware interlocks or by compile-time insertion of NOPs (Null Operations). By rearranging instructions, it is possible to minimize the total pipelined execution time, but the problem of finding this optimal code schedule is well known to be NP-complete. In this paper, we describe a code scheduler …

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An Introductory Study Of The Fiction Of Virginia Frazer Boyle / By Melissa Ann Yow, Melissa Ann Yow

Electronic Theses and Dissertations

No abstract provided.

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Full-Text Articles in Entire DC Network

Design Considerations For High-Pressure Reciprocating Compressors For Refinery Services, S. N. Dwivedi

International Compressor Engineering Conference

Performance Study Of A Prototype Reciprocating Piston Compressor With Special Attention To Valve Design And Gas Pulsation, J. Kim, W. Soedel

International Compressor Engineering Conference

Development Of A Scroll-Type Oil-Free Vacuum Pump, T. Kushiro, K. Miyazaki, H. Kataoka, S. Nii, S. Machida

International Compressor Engineering Conference

Mathematical Model Of Rotary Compressor To Simulate Its Transient Behavior, T. Yanagisawa, T. Shimizu, M. Fukuta, H. Suzuki

International Compressor Engineering Conference

Hermetic Refrigerating Compressors And The Cfc Substitution, E. Heinzelmann, M. S. Ussyk

International Compressor Engineering Conference

Tardis: A Numerical Simulation Package For Drive Systems, W. Suwanwisoot, C. M. Ong

Department of Electrical and Computer Engineering Technical Reports

Fish1d 2.2 User’S Manual, M. S. Lundstrom, M. A. Stettler, T. T. Herman, P. E. Dood

Department of Electrical and Computer Engineering Technical Reports

Local Epitaxial Overgrowth For Stacked Complementary Mos Transistor Pairs, R. P. Zingg, G. W. Neudeck, B. Hoefflinger

Department of Electrical and Computer Engineering Technical Reports

Automatic Parallelization Of Database Queries, Myong H. Kang, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

Image Segmentation Using Human Visual System Properties With Applications In Image Compression, Heidi A. Peterson, Sarah A. Rajala, Edward J. Delp

Department of Electrical and Computer Engineering Technical Reports

3-D Beamspace Ml Based Bearing Estimator Incorporating Frequency Diversity And Interference Cancellation, Ta-Sung Lee, Michael D. Zoltowski

Department of Electrical and Computer Engineering Technical Reports

Commonwealth's Choice: Results From The Massachusetts Public Opinion Survey, Barry Bluestone, Mary Ellen Colten, Thomas Ferguson

McCormack Graduate School General Publications (active until 2013)

A Comparison Of Refrigerant Constant Monitoring Leak Detectors, D. Mcclure, T. Anderson

International Refrigeration and Air Conditioning Conference

The Cfc Problem, Report Of The Situation In France And Evolution, C. Brian

International Refrigeration and Air Conditioning Conference

Heat Transfer Coefficient, Two-Phase Flow Boiling Of Hfc134a, K. Hambraeus

International Refrigeration and Air Conditioning Conference

Compressor Technologies For R-22 Low Temperature Applications, T. Diab, J. Gephart

International Refrigeration and Air Conditioning Conference

The R-134a Energy Efficiency Problem: Factor Fiction, N. Behrens, T. W. Dekleva, J. G. Hartley, F. T. Murphy, R. L. Powell

International Refrigeration and Air Conditioning Conference

A Pressure Sensitive Mat For Measuring Contact Pressure Distributions Of Patients Lying On Hospital Beds, Charles F. Babbs, Joe D. Bourland, George P. Graber, James T. Jones, William E. Schoenlein

Weldon School of Biomedical Engineering Faculty Publications

Quantitation Of The Hydroxyl Radical By Reaction With Dimethyl Sulfoxide, Melissa G. Steiner, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Free Radicals And The Etiology Of Colon Cancer, Charles F. Babbs

Weldon School of Biomedical Engineering Faculty Publications

Accuracy And Precision Of Computer-Simulated Tissue Temperatures In Individual Human Intracranial Tumours Treated With Interstitial Hyperthermia, J A. Deford, Charles F. Babbs, U H. Patel, N E. Fearnot, J A. Marchosky, C J. Moran

Weldon School of Biomedical Engineering Faculty Publications

Hardware Barrier Synchronization: Static Barrier Mimd (Sbm), Matthew T. O'Keefe, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

Surface Passivation Effects Of As2s3 Glass On Self‐Aligned Algaas/Gaas Heterojunction Bipolar Transistors, H. L. Chuang, M. S. Carpenter, Michael R. Melloch, Mark S. Lundstrom, E. Yablonovitch, T. J. Gmitter

Department of Electrical and Computer Engineering Faculty Publications

Orientation-Dependent Perimeter Recombination In Gaas Diodes, T. B. Stellwag, Michael R. Melloch, Mark S. Lundstrom, M. S. Carpenter, R. F. Pierret

Department of Electrical and Computer Engineering Faculty Publications

Theoretical Basis For Controlling Minimal Tumor Temperature During Interstitial Conductive Heat Therapy, Charles F. Babbs, Neal E. Fearnot, J A. Marchosky, C J. Moran, James T. Jones, T D. Plantenga

Weldon School of Biomedical Engineering Faculty Publications

Researches On A Cooler And Cleaner Compressor, Z. Jiang, D. Gao, Q. Hu

International Compressor Engineering Conference

Mechanical Efficiency Of A Variable Speed Scroll Compressor, N. Ishii, M. Yamamura, S. Muramatsu, S. Yamamoto, M. Sakai

International Compressor Engineering Conference

Hardware Barrier Synchronization: Static Barrier Mimd (Sbm), Matthew T. O'Keefe, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

Optimal Code Scheduling For Multiple-Pipeline Processors, Ashar Nisar, Henry G. Dietz

Department of Electrical and Computer Engineering Technical Reports

An Introductory Study Of The Fiction Of Virginia Frazer Boyle / By Melissa Ann Yow, Melissa Ann Yow

Electronic Theses and Dissertations