作者:
Wu, BCYoung, GSschmidt, WChoppella, KDr. Bi-Chu Wu:received a PhD in Mechanical Engineering from the University of Maryland
College Park in 1991. She has worked on projects involving naval architecture design optimization solid mechanics and database development. Presently a senwr engineer with Angle Incorporated Dr Wu's research interests are in design optimization and fuzzy logic applications. Dr. Gin-Shu Young:
a senior engineer with Angle Incorporated holds a PhD in Mechanical Engineering from the University of Maryland College Park. As a guest researcher with National Institute of Standards and Technologies from 1990 to 1993 he worked on vision-based navigation for autonomous vehicles. His experience also includes applications of optimization fuzzy logic neural network and genetic algorithm methods to engineering system design Mr. William Schmidt:co-founded Angle Incorporated in 1990 and has served as Vice PresidentlChiefScientist during this tame. He holds a B.Sc. in Applied Science from the Naval Acadt?my and an M.Sc. in Physics from the Naval Post Graduate School. He has cner 20 years experience in technical leadership
material and personnel management. He has led the application of computer aided design (CAD) and Product Model Information Exchange to the shipbuilding industry. His experience also includes leading the amlication of model based operational analysis to support the Live Fire Test Program for DDG 51 Class Destroyers. Mr. Krishna M. Choppella:is a Sofware Engineer at Eidea Laboratories
Incotporated where he works on componentbased distributed enterpvise frameworks. He has been involved in creating data analysis tools for the US Nay by integrating CAD modeis databases and graphical front ends. His work in the Masters degree program in Mechanical Engineering at the University of Texas at Austin was in di0ddase.r spectroscopy of combustion products in porous-matri burners. He received his Bachelors degree in Electrical Engineering in India. He was a Research Associate at the Centre for Laser Technology and Project Engi
Ship design is often multidisciplinary involving several design elements with various types of objectives and constraints (O/C) some easily described as mathematical formulas, others better modeled as descriptive asse...
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Ship design is often multidisciplinary involving several design elements with various types of objectives and constraints (O/C) some easily described as mathematical formulas, others better modeled as descriptive assertions. This paper describes a method based on fuzzy functions and an integrated performance index to model O/C using descriptive assertions to be used with mathematical formulas in optimization. Another issue addressed in this paper concerns the coordination of design elements when sequentially coupled, that is, when one leads the other and the performance of the follower depends greatly on the design of the leader. Based on neuro-fuzzy techniques, the method described here coordinates and optimizes sequentially coupled elements. The two methods are applied to machinery arrangement (mA) and pipe routing (PR). Preliminary models for optimization of mA and PR are described considering convenience, producibility: engine room size, interference and location as factors in the O/C set. Some test results frommA/PR applications are presented and discussed. The methods are generic and can be extended to other elements in ship design. They are mutually independent and may be used separately Two advantages of their use are an improvement in overall performance and a reduction in the need for redesign of elements.
作者:
malard, FPlenet, SGibert, JFlorian Malard (Groundwater Hydrobiology and Ecology Laboratory
University of Lyon I Bat. 403 43 Bd du 11 Nov. 1918 69622 Villeurbanne France) graduated from the Agricultural Engineering College of Dijon in 1989. He joined the Geography Department of Loughborough University of Technology in 1989 the Ecology Laboratory of the University of Dijon in 1991 the Hydrogeology Laboratory of the University of Montpellier in 1992 and the Groundwater Hydrobiology and Ecology Laboratory of the University of Lyon I in 1993. He received an M.Sc. degree and a Ph.D. in hydrobiology from the University of Lyon I in 1991 and 1995 respectively. His most recent work has been in the field of organic contamination of karstic aquifers as related to ground water invertebrates. Sandrine Plenet (Groundwater Hydrobiology and Ecology Laboratory
University of Lyon I Bat. 403 43 Bd du 11 Nov. 1918 69 622 Villeurbanne France) received her Ph.D. in hydrobiology from the University of Lyon in 1993 where she is currently an assistant lecturer. Her research interest is the influence of environmental variables on the dynamics of invertebrate communities with special emphasis on the impact of contaminants such as heavy metals on interstitial invertebrate assemblages. From 1991 to 1993 her work involved the search for indicator species of ground water contamination within the framework of a French Water Agency environmental program. Janine Gibert (Groundwater Hydrobiology and Ecology Laboratory
University of Lyon I Bat. 403 43 Bd du 11 Nov. 1918 69 622 Villeurbanne France) is a professor at the University of Lyon I. She is also head of the Freshwater and River Ecology Research Unit 1974 of the C.N.R.S. and head of the Groundwater Hydrobiology and Ecology Laboratory of the University of Lyon I. She is engaged in collaborative research projects on a wide range of issues exploring ground water ecology in the perspective of environmental sustainability. She is involved in international programs on the ecology and management of aquat
The use of invertebrates as biomonitors of ground water quality is a relatively new approach that has come of age with the development of ground water ecology. The benefits of such an approach are illustrated by four ...
The use of invertebrates as biomonitors of ground water quality is a relatively new approach that has come of age with the development of ground water ecology. The benefits of such an approach are illustrated by four examples of field biomonitoring from several sites in various hydrogeological settings. Contamination of the interstitial zone by heavy metals in some sectors of the Rhone River (France) was shown by the scarcity of insect species;sewage pollution in the saturated zone of a karstic aquifer was indicated by the low relative abundances of stygobites as compared with those of stygophiles and stygoxenes;and enrichment with organic matter of an underflow was dearly demonstrated by the extremely high density of ground water invertebrates such as oligochaetes, ostracods, and isopods. Examination of the spatial changes in the composition and abundance of invertebrate assemblages was also useful in determining the direction and intensity of water fluxes between a river and its underflow, as well as in delineating the reduced or oxidized zones in a manganese-polluted aquifer. Finally, the selected case studies emphasized the variety of methodological approaches that could be developed in ground water contamination biomonitoring, as well as the complementary and sometimes new information provided by this innovative method in comparison with that obtained by conventional pollution monitoring techniques.
Nitrate levels in the ground water of the Central Valley of Costa Rica have increased in relation to the past. Previous studies determined that the unsewered sanitation systems in the recharge areas are the main sourc...
Nitrate levels in the ground water of the Central Valley of Costa Rica have increased in relation to the past. Previous studies determined that the unsewered sanitation systems in the recharge areas are the main source of nitrogen. Calculations are made in this study to estimate the maximum population density allowable without improved sewage systems in order to keep the nitrogen levels in ground water below the World Health Organization (WHO) criteria. Results were achieved employing a mass balance that involved the concentration and rate of domestic effluents and the flow rate in the aquifer, as well as an estimation of the effects caused by the agricultural activity. It was concluded that, in general terms, the population density must not exceed 45 inhabitants per hectare. Otherwise, sewage systems and treatment plants are necessary. These conclusions provide a basis for urban growth planning, which will protect ground water quality. The method used in this case should apply to similar situations.
This paper describes the implementation of transmission-line matrix (TLm) method algorithms on a massively parallel computer (DECmpp 12000), the technique of distributed computing in the UNIX environment, and the comb...
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This paper describes the implementation of transmission-line matrix (TLm) method algorithms on a massively parallel computer (DECmpp 12000), the technique of distributed computing in the UNIX environment, and the combination of TLm analysis with Prony's method as well as with autoregressive moving average (ARmA) digital signal processing for electromagnetic field modelling. By combining these advanced computation techniques, typical electromagnetic field modelling of microwave structures by TLm analysis can be accelerated by a few orders of magnitude.
作者:
POND, LCLI, VOKCommunication Sciences
Electrical Engineering Systems University of Southern California Los Angeles CA 90089-2565 U.S.A. Lawrence C. Pond received the M.Sc. and Ph.D. degrees in electrical engineering from the University of Southern California in 1983 and 1990
respectively. Dr. Pond is currently a scientist at Hughes Space and Communications Company having joined in 1980. He has worked in the fields of communication system design mobile communication network and spacecraft payload design. He is currently working on the development of satellite-based ATM transport and switching architectures for BISDN and Defense Information System Network amlications. Dr. Pond is a member of IEEE. Victor O. K. Li was born in Hong Kong in 1954. He received his SB
SM and Sc.D. degrees in Electrical Engineering and Computer Science from the Massachusetts Institute of Technology Cambridge Massachusetts in 1977 1979 and 1981 respectively. Since February 1981 he has been with the University of Southern California (USC) LOS Angeles California where he is Professor of Electrical Engineering and Director of the USC Communication Sciences Institute. He has published 150 technical papers and has lectured and consulted extensively around the world. His research interests include high-speed communication networks personal communication networks intelligent networks distributed databases queueing theory graph theory and applied probability. Dr. Li is very active in the Institute of Electrical and Electronic Engineers (IEEE) having been a member of the Computer Communications Technical Committee since 1983 and having served as Chairman from 1987–1989. He served as Chairman of the Los Angeles Chapter of the IEEE Information Theory Group from 1983–1985. He is the Steering Committee Chair of the International Conference on Computer Communications and Networks (IC3 N) General Chair of the 1st Annual IC3N held in San Diego California in June 1992 General Chair and Technical Program Chair of the 4th IEEE Workshop on Comp
In this, the second part of a two-part paper, the required time for establishing a mobile packet radio network using the virtual circuit and time division multiple access protocol developed in Part 1 is analysed. Tool...
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In this, the second part of a two-part paper, the required time for establishing a mobile packet radio network using the virtual circuit and time division multiple access protocol developed in Part 1 is analysed. Tools are developed to determine the virtual circuit and network set-up times in terms of the channel bandwidth allocated to establish and maintain the network. The tools are then extended to include the effects of user mobility. Then these results are combined with the network capacity results of Part 1 to analyse the trade-off between the data rate and set-up time of the network. Next a hierarchical architecture is proposed and the network data rate versus set-up time trade-off of this architecture is analysed using these tools. This architecture is shown to both provide a higher data rate and establish faster than flat networks of the same number of nodes.
In this article a multimedia computer-assisted learning (mCAL) system is presented. The major objective of this work was to investigate the potential of using such systems as tools for transferring instructional cours...
In this article a multimedia computer-assisted learning (mCAL) system is presented. The major objective of this work was to investigate the potential of using such systems as tools for transferring instructional course information through various types of computer media as opposed to the classic CAL systems. The philosophy and techniques employed to design the system are investigated. Usage of the implemented system and its merits have been illustrated through its application to teach engineering students and technicians the theory and concepts of marine radar. System design, implementation, test, and revision phases are presented and discussed.
In this paper the temperature distribution on the section vertical to the axis of an asynchronous machine is calculated. For the calculation the numerical method of “Control Volumes” has been used. The technique use...
作者:
YEARSLEY, ENCROWDER, REIRONS, LAElliot N. Yearsley is a geological engineer and log analyst for Colog Inc. (Borehole Geophysical Services
1019 Eighth St. Golden CO 80401). He received his B.Sc. in geological engineering from the Colorado School of Mines (CSM) in 1981 later returning to CSM to earn a M.Sc. in engineering mechanics in 1989. Between degrees Yearsley was employed as a geological engineer for Tenneco Oil Co. where he pioneered the use of measurement while drilling (MWD) formation evaluation. He is currently working on new borehole geophysical techniques applied to geotechnical and hydrogeological investigations including monitoring well completion evaluation and full waveform acoustic analysis applied to permeability determinations. Robert E. Crowder is president of Colog Inc. (Borehole Geophysical Services
1019 Eighth St. Golden CO 80401) and has 12 years of diversified experience in borehole geophysical applications including environmental geotechnical and mineral investigations. Prior to forming Colog he was operations manager for Colorado Well Logging for eight years. He has taught numerous courses for client groups in borehole geophysical logging and log interpretation both domestic and international. He received his degree in engineering geophysics from Colorado School of Mines in 1978. Larry A. Irons is a senior associate geophysicist at Ebasco Environmental Services (143 Union Blvd.
Ste. 1010 Lakewood CO 80228). He graduated from the University of Nebraska in 1977 with a B.Sc. in geology. During 1977–79 he conducted research for the Antarctic Research Program of the University of Nebraska earning an M.Sc. in geology with a mathematics minor. During 1979–86 Irons worked as an exploration geophysicist for several major oil companies. He is currently conducting remedial investigations of hazardous waste sites using borehole magnetic gravity electromagnetic and seismic geophysical methods.
Grout continuity and the location of the bentonite seal and sand pack in PVC-cased monitoring wells can be evaluated with cased-hole geophysical density logs. This method relies upon density contrasts among various co...
Grout continuity and the location of the bentonite seal and sand pack in PVC-cased monitoring wells can be evaluated with cased-hole geophysical density logs. This method relies upon density contrasts among various completion conditions and annular materials. Notably, the lack of annular material behind pipe (i.e., void space) creates a low-density zone that is readily detected by borehole density measurements. Acoustic cement bond logging has typically been applied to the evaluation of cement in the annular space of completed oil and gas production wells, and in some cases to ground water monitoring wells. These logs, however, can only be obtained in the fluid-filled portion of the borehole, and their interpretation is severely hindered by the presence of the micro-annulus between casing and cement. The influence of the micro-annulus on cement bond logs can be mitigated in steel-cased wells by pressurizing the wellbore during acquisition of the log, but this procedure is not feasible in PVC-cased monitoring wells. The micro-annulus does not affect cased-hole density logs or their interpretation. Empirical measurements made in the laboratory with density probes provide information on their depths of investigation and response to specific completion conditions. These empirical data, and general knowledge of the density of annular completion materials (sand, bentonite, cement), are used to support interpretations of cased-hole density logs acquired in the field. Three field examples demonstrate the applicability of geophysical density logs to the evaluation of PVC-cased monitoring well completions.
作者:
FEENSTRA, SmACKAY, DmCHERRY, JAStan Feenstra is a hydrogeochemist and president of Applied Groundwater Research Ltd. in Mississauga
Ontario He received a B.Sc. in earth sciences and an M.Sc. in hydrogeology from the University of Waterloo in 1978 and 1980 respectively and was designated a Certified Ground Water Professional by AGWSE in 1989. Since 1980 he has been a ground water consultant with Golder Associates in Mississauga Ontario and Zenon Environmental in Burlington Ontario and founded Applied Groundwater Research Ltd. in 1987. Feenstra specializes in the hydrogeochemical evaluation of ground water contamination at waste disposal facilities and chemical spill sites. He is currently a Ph.D. candidate in hydrogeology and research associate in the Waterloo Centre for Ground Water Research at the University of Waterloo (Waterloo Ontario N2L 3G1) and is involved in research related to the behavior of dense organic solvents in ground water. Douglas M. Mackay is an adjunct professor at the Waterloo Centre for Groundwater Research at the University of Waterloo
Waterloo Ontario (N2L3G1). Dr. Mackay received a B.S. in engineering and M.S. and Ph.D. in civil engineering from Stanford University in 1970 1973 and 1981 respectively. From 1986 to 1990 he was a faculty member of the Environmental Science and Engineering Program of the UCLA School of Public Health. His research focuses on field studies of transport and fate of organic chemicals in ground water various scale studies of decontamination of soil and ground water and ground water monitoring technologies. John A. Cherry is a professor at the Waterloo Centre for Groundwater Research at the University of Waterloo
Waterloo Ontario (N2L 3G1). He received his B.S. in geological engineering from the University of Saskatchewan in 1962. He received his M.S. from the University of California at Berkeley in 1964 and his Ph.D. from the Department of Geology at the University of Illinois in 1966. His research interests include the field study and modeling of contaminants in ground wat
Ground water contamination by non-aqueous phase liquid (NAPL) chemicals is a serious concern at many industrial facilities and waste disposal sites. NAPL in the form of immobile residual contamination, or pools of mob...
Ground water contamination by non-aqueous phase liquid (NAPL) chemicals is a serious concern at many industrial facilities and waste disposal sites. NAPL in the form of immobile residual contamination, or pools of mobile or potentially mobile NAPL, can represent continuing sources of ground water contamination. In order to develop rational and cost-effective plans for remediation of soil and ground water contamination at such sites, it is essential to determine if non-aqueous phase liquid (NAPL) chemicals are present in the subsurface and delineate the zones of NAPL contamination. The presence of NAPL pools may be evident as a floating or sinking phase in monitoring wells. The residual NAPL contamination may be identified in soil samples if residual contents are high and contaminated zones in the soil cores are thick. However, visual identification may not be effective if residual contents ar elow or if the NAPL residual is distributed heterogeneously in the samples. The chemical analysis of soil samples provides a measure of the total chemical concentration in the soil but cannot determine directly whether NAPL is present in the samples. Qualitatively, soil analyses that exhibit chemical concentrations in the percent range or > 10,000 mg/kg would generally be considered to indicate the presence of NAPL. However, the results of soil analyses are seldom used in a quantitative manner to assess the possible presence of residual NAPL contamination when chemical concentrations are lower and the presence of NAPL is not obvious. The assessment of the presence of NAPL in soil samples is possible using the results of chemical and physical analyses of the soil, and the fundamental principles of chemical partitioning in unsaturated or saturated soil. The method requires information on the soil of the type typically considered in ground water contamination studies and provides a simple tool for the investigators of chemical spill and waste disposal sites to assess whether soil
This paper reports on an investigation of the applicability of recent hull efficiency improvement concepts to U.S. Navy ships. Among the concepts investigated were stern flaps, Grim Wheels, alternate aftbody configura...
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This paper reports on an investigation of the applicability of recent hull efficiency improvement concepts to U.S. Navy ships. Among the concepts investigated were stern flaps, Grim Wheels, alternate aftbody configurations, bulbous bows, and flow modifying ducts. Extensive model testing was conducted at the David Taylor Research Center (DTRC) for each concept, and care was taken to check out critical propeller cavitation and noise aspects associated with the investigation of alternate stern configurations and Grim Wheel concepts. A guiding principle in this program was to utilize the expertise available both here and abroad so that each design concept would have the greatest chance of success. As a result of these investigations, significant gains in fuel economy were obtained. Specifically, full scale trials of FFG-25 (USS Copeland), equipped with and without a stern flap, demonstrated that fuel savings of 5-9% are achieved at speeds above 12 knots. In addition, fuel savings of 9.4% for T-AGS 39 equipped with a Grim Wheel and 5.6% for the combination of a large bulbous bow and a large diameter/low RPm propeller on AE-36 have been predicted. The paper concludes with a direction for future applications to U.S. Navy, and other ships.
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