检索结果-内蒙古大学图书馆

COMPARISON OF STAINLESS-STEEL VS PTFE MINIWELLS FOR MONITORING HALOGENATED ORGANIC SOLUTE TRANSPORT

GROUND WATER MONITORING AND REMEDIATION 1992年第4期12卷 126-131页

作者： BIANCHIMOSQUERA, GC MACKAY, DM Gino Bianchi-Mosquera (51 Claremont Ave. Long Beach CA 90803) is a project geochemist with Watkins-Johnson Environmental Inc. He received a B.A. degree in geochemistry from Occidental College Los Angeles California an M.S. degree in geochemistry from The Pennsylvania State University and a D.Env. degree from the University of California Los Angeles in 1982 1986 and 1992 respectively. His research interests include the transport and fate of organic compounds in the subsurface and in the evaluation of new aquifer cleanup techniques. Douglas Mackay is adjunct professor in the Centre for Groundwater Research at the University of Waterloo (Waterloo Ontario N2L3G1) Canada and a visiting scientist at the UCLA Department of Civil Engineering. From 1986 to mid-1990 he was a faculty member in 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 and ground water decontamination technologies. Dr. Mackay received a B.S. in engineering and M.S. and Ph.D. degrees in civil engineering from Stanford University in 1970 1973 and 1981 respectively.

Field tests of organic solute transport behavior have often been monitored using small-diameter wells (miniwells). To determine if experimental results could be significantly biased by sorption to, desorption from, or diffusion through sampling lines, dissolved concentrations of tetrachloroethene and carbon tetrachloride were measured in ground water samples collected simultaneously from the same spatial location during a forced-gradient test in the Borden aquifer using polytetrafluoroethene (PTFE) and stainless steel miniwells (1/8-inch O.D.). A semiautomated organic analytical system was used on-site to obtain real-time results, which avoided sample holding problems and permitted optimizing sampling times. The breakthrough curves (plots of concentration vs. time) for both organic compounds indicate that under the conditions of this experiment (low organic solute concentrations, short exposure time of sampling lines to the plume. adequate flushing of sampling lines) there is no significant difference between concentration histories (breakthrough curves) collected using a polytetrafluoroethene sampling line and those collected using a stainless steel sampling line. This suggests that organic solute tailing seen in this and also in a similar transport experiment previously conducted at the site is the result of transport processes in the aquifer rather than an artifact introduced by the PTFE miniwells.

关键词：

来源：评论

学校读者我要写书评

暂无评论

The reaction γ +d → π⁺ + π^-+p + n between 570 and 850 MeV and Δ⁺⁺Δ^- production

引用

Zeitschrift für Physik A Hadrons and Nuclei 1992年第3期344卷 335-344页

作者： Asai, M. Endo, I. Harada, M. Kasai, S. Niki, K. Sumi, Y. Kato, S. Maruyama, K. Murata, Y. Muto, M. Yoshida, K. Iwatani, K. Hasai, H. Ito, H. Maki, T. Rangacharyulu, C. Shimizu, H. Wada, Y. Department of Physics Hiroshima University Higashi-Hiroshima 724 Japan Department of Electrical Engineering Hiroshima Institute of Technology Hiroshima 731-51 Japan Ricoh Co. Ltd. Tokyo 112 Bunkyo-ku Japan Institute for Nuclear Study University of Tokyo Tanashi 188 Japan Department of Applied Physics and Chemistry Hiroshima University Higashi-Hiroshima 724 Japan Department of Physics Saga University Saga 840 Japan University of Occupational and Environmental Health Kitakyushu 807 Japan Department of Physics University of Saskatchewan Saskatoon S7N 0W0 Canada Department of Physics Faculty of General Education Yamagata University Yamagata 990 Japan Meiji College of Pharmacy Tokyo 154 Japan Institute for Nuclear Study University of Tokyo Tanashi 188 Japan Sumisho Computer Service Corporation Tokyo 101 Japan

The reaction γ+d → π++π-+p + n has been measured in a kinematically complete way at incident photon energies from 570 to 850 MeV in steps of 40 MeV. From detailed comparison of measured data with results of event ... 详细信息

The reaction γ+d → π⁺+π^-+p + n has been measured in a kinematically complete way at incident photon energies from 570 to 850 MeV in steps of 40 MeV. From detailed comparison of measured data with results of event simulations, it is concluded that three different mechanisms, the quasi-free, double-delta and phase space productions, contribute to the reaction. Each of the cross sections corresponding to these mechanisms is determined separately. © 1993 Springer-Verlag.

关键词： 13.60.Rj 14.20.Gk 25.20.Lj

来源：评论

学校读者我要写书评

暂无评论

A HYBRID-MODE BOUNDARY INTEGRAL-EQUATION METHOD FOR NORMALCONDUCTING AND SUPERCONDUCTING TRANSMISSION-LINES OF ARBITRARY CROSS-SECTION

引用

INTERNATIONAL JOURNAL OF MICROWAVE AND MILLIMETER-WAVE COMPUTER-AIDED engineering 1992年第4期2卷 314-330页

作者： SCHROEDER, W WOLFF, I Department of Electrical Engineering and Sonderforschungsbereich 254 Duisburg University Bismarckstrasse 81 D-4100 Duisburg 1 Germany Werner L. Schroeder was born in Recklinghausen Germany on July 12 1954. After an apprenticeship as an electrician he collected several years of practical experience in industry before it drew him to study electrical engineering. He obtained his Dipl.-Ing degree from the University of Duisburg Germany in 1986. He then joined the Special Research Program. “Very High Frequency and Very High Speed Circuits based on III-V-Compound Semiconductors” at the Faculty of Electrical Engineering University of Duisburg where he worked on Monte Carlo simulation of electrical transport in III-V compounds and devices numerical modeling of MMIC transmission-line structures and on the explanation of the spurious mode phenomenon in numerical solutions of electromagnetic field eigenvalue problems. He is currently with the Department of Electromagnetic Theory and Engineering working on fullwave boundary integral analysis of general waveguiding structures which is also the subject of his dissertation.

A space domain Boundary Integral Equation (BIE) method for full-wave analysis of general waveguide is presented. The method is demonstrated to be applicable to arbitrary shielded or unshielded waveguide cross-sections ranging from optical waveguide to MMIC transmission lines. It allows for arbitrary isotropic complex media including normal (imperfect) conductors and superconductors as is demonstrated with full-wave loss analysis of coplanar stripline and several thin-film microstrip line configurations employing Au and YBCO conductors. An outline of the theory of the BIE method is given. The implications of nonsmooth boundary curves are considered, and special attention is given to the reliability of the method in being free of spurious solutions.

关键词： Waveguides

来源：评论

学校读者我要写书评

暂无评论

EVALUATING THE EFFECTIVENESS OF GROUND-WATER EXTRACTION SYSTEMS

引用

GROUND WATER MONITORING AND REMEDIATION 1991年第1期11卷 119-124页

作者： HALEY, JL HANSON, B ENFIELD, C GLASS, J Jennifer Haley is a chemical engineer working in the Remedial Operations and Guidance Branch of the Hazardous Site Control Division/Office of Emergency and Remedial Response (U.S. EPA OS-220 401 M St. SW Washington D.C. 20460). One of her responsibilities during her three years at EPA has been completion of the EPA Guidance on Remedial Actions for Contaminated Ground Water at Superfund Sites. Prior to taking her current position at the EPA in May 1987 she worked for two years for the California Regional Water Quality Control Board overseeing ground water contamination investigations and cleanups in the South San Francisco Bay. She received a B.S. in chemical engineering from the University of California in Berkeley and an M.S. in environmental management from the University of San Francisco. Bill Hanson is an engineer with the U.S. Environmental Protection Agency (OS-220 401 M St. SW Washington D.C. 20460). He received both his B.S. in engineering and M.A. in environmental engineering from Duke University. Before joining the Environmental Protection Agency Hanson worked for several consulting engineering firms including CH2M Hill in Res ton Virginia. At EPA he first worked in the Effluent Guidelines Program where he was responsible for developing pretreatment and direct discharge regulations for the electroplating industry. Hanson has been with the Superfund program since its start. He is currently chief of the Remedial Operations and Guidance Branch. His branch is responsible for developing guidance for consistency of approach with respect to selection of remedy land ban treatment requirements and treatability protocols. Carl G. Enfield is a soil scientist at the Robert S. Ken Environmental Research Laboratory (U.S. EPA Office of Research and Development P.O. Box 1198 Ada OK 74820). He earned his B.S.C.E. in civil engineering and M.S. in agronomy at Purdue University and his Ph.D. in agricultural chemistry and soils at the University of Arizona. He currently serves as research director at EP

The most common process for remediating contaminated ground water is extraction and treatment. Data from 19 on-going and completed ground water extraction systems were collected and analyzed (U.S. EPA 1989b) to evaluate the effectiveness of this process in achieving cleanup concentration goals for ground water. This analysis indicated several trends including (1) containment of ground water plumes was usually achieved;(2) contaminant concentrations dropped significantly initially followed by a leveling out;(3) after the period of initial rapid decline, the continued decreases in concentration were usually slower than anticipated;and (4) certain data important to optimizing system design and operation had often not been collected during the site characterization phase. Factors limiting the achievement of cleanup concentration goals fell into four basic categories: (1) hydrogeological factors, such as subsurface heterogeneity, low-permeability units, and presence of fractures;(2) contaminant-related factors, such as high sorption to soil and presence of non-aqueous phases (dissolution from a separate non-aqueous phases (dissolution from a separate non-aqueous phase or partitioning of contaminants from the residual non-aqueous phase);(3) continued migration from source areas and the size of the plume itself;and (4) system design factors, such as pumping rates, screened intervals, and extraction well locations. The findings of this study indicate that ground water extraction is an effective method for preventing additional migration of contaminant plumes and achieving risk reduction. However, the findings indicate that in many situations, it may not be practicable to rely solely on ground water extraction and treatment to achieve health-based cleanup concentrations throughout the contaminated zone and fulfill the primary goal of returning ground water to beneficial use. This study suggests several recommendations (U.S. EPA 1989a) for improving ground water response acti

关键词：

来源：评论

学校读者我要写书评

暂无评论

A METHOD FOR ASSESSING RESIDUAL NAPL BASED ON ORGANIC-CHEMICAL CONCENTRATIONS IN SOIL SAMPLES

引用

GROUND WATER MONITORING AND REMEDIATION 1991年第2期11卷 128-136页

作者： FEENSTRA, S MACKAY, DM CHERRY, JA Stan 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 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

关键词：

来源：评论

学校读者我要写书评

暂无评论

A NATIONAL EVALUATION OF THE LEACHING POTENTIAL OF ALDICARB .2. AN EVALUATION OF GROUND-WATER MONITORING DATA

引用

GROUND WATER MONITORING AND REMEDIATION 1990年第1期10卷 127-141页

作者： LORBER, MN COHEN, SZ DEBUCHANANNE, GD Matthew Lorber has been with the U.S. Environmental Protection Agency (401 MSt. s. W. WashingtonD.C. 20460) since 1984 working on issues related to pesticides in ground water. He obtained a B.S. and an M.S. in agricultural engineering from Cornell Universitymajoring in soil and water processes with a minor in public policy. He began his career with an EPA research-laboratory in Athens Georgia where he investigated pesticide runoff and leaching processes. He joined the faculty ofthe University of Florida in Gainesville in 1982 where he worked two years on a methane-from-biomass research project. He rejoined EPA at its headquarters in 1984 where he was a member of the Ground- Water Team of the Office of Pesticide Programs. Since the early part of 1989 he has been the project officer on the implementation contract for EPA 's National Survey for Pesticides in Drinking Water Wells. Stuart Cohen is the manager of Ground Water and Environmental Programs at Biospherics Inc. (12051 Indian Creek Ct. Beltsville MD 20705). His program conducts ground water monitoring studies for pesticides and environmental audits for real estate transactions. He received a B.S. in chemistry from the University of Maryland-Baltimore County and a Ph.D. in physical organic chemistry from George Washington University with thesis work in hydrolysis reactions. He joined EPA in 1976 has been working in the area of pesticides in ground water since 1979 and became Ground- Water Team leader in 1984. He joined Biospherics in 1986.Cohen has many publications in the area and is the author of the column “Agricultural Chemicals News” which appears in an issue of Ground Water Monitoring Review. George DeBuchananne obtained a B.S. in geology from the University of Iowa with continuing graduate work at the Universities ofIowa and Tennessee. He spent the next 35 years at USGS Water Resources Division. He worked on topics including the availability of ground water toxic and radioactive waste disposal and artificial recharge. Since 1980 he

Aldicarb was first found in ground water in Suffolk County, New York, in the late 1970s associated with its use on potatoes. Since then, there has been a substantial amount of monitoring associated with aldicarb use on potatoes nationally and on citrus in Florida. A recent monitoring study by the registrant of aldicarb supplemented limited monitoring data on other critical aldicarb uses including cotton and peanuts. This paper reports on monitoring programs and studies encompassing more than 50,000 ground water samples, of which approximately 32 percent are positive and 13 percent are above EPA's Health Advisory Level of 10 ppb. These monitoring results were used in an integrated assessment to identify areas of the United States where aldicarb is likely to leach to ground water (Lorber et al. 1989). Positive findings are reported for 61 counties in 19 states, and findings above 10 ppb are reported for 31 counties in 11 states. Monitoring data associated with the use of aldicarb on potatoes in the Northeast and upper Midwest (Wisconsin, Virginia, New York, Massachusetts, Rhode Island, Maine) are extensive and demonstrate the potential for aldicarb to impact ground water near potato-use sites. In contrast, monitoring associated with potato use in the Northwest (Idaho, Oregon, Washington) and a three-county potato-growing area in Florida have shown negative results. Sampling near cotton use in the South and Southwest (Georgia, Alabama, Tennessee, Arkansa, Louisiana, Texas, Arizona) showed negative findings, while a small number of positives were found in North Carolina and South Carolina. Limited monitoring associated with peanuts showed negative results in the South (North Carolina, South Carolina, Georgia), although sampling beneath a field research site in Georgia showed trace positives. Sampling from monitoring wells established in the shallow water table aquifer beneath and downgradient from citrus use sites in Florida showed both a high frequency and high concent

关键词：

来源：评论

学校读者我要写书评

暂无评论

AN OVERVIEW OF THE ROLE OF THE NAVSEA HUMAN-FACTORS engineering program IN SHIP DESIGN

引用

NAVAL ENGINEERS JOURNAL 1983年第4期95卷 139-152页

作者： STEIN, NI BENEL, RA MALONE, TB Mr. Norman I. Stein:received his degree in mechanical engineering from the University of Iowa in 1943. MK Stein began his career with the Bureau of Ships Department of the Navy. After his military service with the Army of Occupation in Japan he has held positions with the Corps of Engineering Atomic Energy Commission Walter Reed Army General Hospital and the Protective Structures Development Center Department of the Army. He returned to the Naval Sea Systems Command in 1967 and is currently with the Manning and Controls Integration Branch SEA 55 W16. Mr. Stein is a registered professional engineer in New York state and also is a certified fallout shelter analyst with the Department of the Army. He has authored a comprehensive study on air distribution studies in multi-room shelters presentedpapers on human factors engineering to the Association of Scientists and Engineers and recently contributed a chapter on human factors engineering which will be incorporated in the proposed Naval Sea Systems Handbook on Surface Ship Design. Russell A. Benel:received his Ph. D. in engineering psychology from the University of Illinois at Urbana-Champaign. He is currently a Senior Research Scientist with Essex Corporation where he is the manager of the Man-Machine Systems Department. He has been responsible f o r scientific studies associated with the Human Factors Engineering f o r ships program under contract to the Naval Sea Systems Command specifically the development application and validation of human factors engineering technology f o r surface ship systems such as aircraft launch and recovery propulsion engineering combat direction weapons and total ship systems. He is currently providing Human Factors Engineering Support on the DDG-51. His other activities include a variety of research development test and evaluation activities for military systems. He had been with the Crew Performance Branch of the Crew Technology Division at the USAF School of Aerospace Medicine as a National Research Council Postd

This paper provides a context within which the role of human factors engineering (HFE) for Naval ship design may be understood. HFE is defined and its history as part of engineering design teams is traced. The role of HFE in ship systems design is defined, and the HFE Technology for Ships program, managed by SEA 061R, is described. The rationale for inclusion of HFE in the design process is presented, the methodology whereby it is incorporated into the design process is detailed, methodology to assess the application of HFE is outlined, and the benefits that will accrue as a result of inclusion of HFE considerations in the design process are documented. The counterpoint to inclusion is illustrated through instances of design-induced human errors. A specific application of HFE in the acquisition process is illustrated through use of the Landing Craft, Air Cushion HFE program plan. The difficulties which may be encountered as the size of the target system expands are described. Potential roadblocks to the required incorporation of HFE are examined for their source and possible ameliorative steps.

关键词：

来源：评论

学校读者我要写书评

暂无评论

RUDDER ROLL STABILIZATION FOR COAST GUARD CUTTERS AND FRIGATES

引用

NAVAL ENGINEERS JOURNAL 1983年第3期95卷 267-282页

作者： BAITIS, E WOOLAVER, DA BECK, TA Dr. Erich Baitis: a native of Germany came to the David W. Taylor Naval Ship Research and Development Center in 1957 as a co-operative student/trainee and received his Bachelor of Science Degree in Physics from Virginia Polytechnic Institute. As a 32-year-old naval architect in 1971 he received both the VietnamHonorServiceMedaland the Navy'sMeritoriousCivilianServiceAwardfor his eight months as liaison with the Vietnamese NAVVS ferro-cement ship program. As head of the Seakeeping and Stabilization Group of the Surface Ship Dynamics Branch his work has led to the development of a new standard Ship Motion Computer Program and the application of ship motions to ship habitability operability and survivability problems. A major area of this work has been the ship/aircraft interface which is particularly sensitive to ship motions wind and other environmental factors. Mr. Dennis A. Woolaver:has been employed as a Naval Architect at the David W. Taylor Naval Ship Research and Development Center since 1965 where his work has resulted in numerous patents. He received his Bachelor of Science Degree in Electrical Engineering from George Washington University where he also completed graduate work in Communication Theory. Additional fields of study include Computer Science and Personnel Management. Current efforts are directed toward surface ship motion mitigation data acquisition and statistical analysis. He is a member of the Society of Naval Architects and Marine Engineers. Lt. Tom A. Beck USCG: joined the UnitedStatesCoastGuardin 1966 where he trained as an Electronics Technician. He received a Bachelor of Science Degree in Electrical Engineering from Columbia University in 1978. From 1978 to 1979 he was an Electronics Project Officer at the CoastGuardElectronics Laboratory in Alexandria Virginia. Since 1980 he has been a Research and Development Project Officer in the Sensor Technology Branch of the CoastGuardsOffice of Research and Development. Lt. Beck is a member of the Institute of Electronic and Elect

The potential use of rudders as anti-roll devices has long been recognized. However, the possible interference of this secondary function of the rudder with its primary role as the steering mechanism has prevented, for many years, the development of practical rudder roll stabilizers. The practical feasibility of rudder roll stabilization has, however, in recent years been demonstrated by two systems designed and developed for operational evaluation aboard two different U.S. C oast G uard Cutters, i.e., Jarvis and Mellon of the 3,000-ton, 378-foot HAMILTON Class. The authors describe the major components of the rudder roll stabilization (RRS) system, along with the design goals and methodology as applied to these first two prototypes. In addition, a brief history of the hardware development is provided in order to show some of the lessons learned. The near flawless performance of the prototypes over the past four years of operational use in the North Pacific is documented. Results from various sea trials and reports of the ship operators are cited and discussed. The paper concludes with a discussion of the costs and benefits of roll stabilization achieved using both a modern anti-roll fin system, as well as two different performance level RRS systems. The benefits of roll stabilization are demonstrated by the relative expansion in the operational envelopes of the USS OLIVER HAZARD PERRY (FFG-7) Class. The varying levels of roll stabilization suggest that the merits of fins and RRS systems are strongly dependent on mission requirements and the environment. The demonstrated performance of the reliable RRS system offers the naval ship acquisition manager a good economical stabilization system.

关键词：

来源：评论

学校读者我要写书评

暂无评论

THE “TRADE—OFF” BETWEEN LEARNING AND INFLATION IN SHIPBUILDING

引用

Naval Engineers Journal 1978年第4期90卷 23-40页

作者： FRISCH, FRANZ A.P. TODD, CHARLES Dr. Franz A.P. Frischgraduated from the Technical University of Vienna in Austria. He has thirty years' experience in shipbuilding and related subjects. He has worked as a Naval Architect Guarantee Engineer Chief Estimator Production Manager and Director for Shipyard Planning and Maintenance in Austria Denmark Sweden and Germany. In 1956 he was first invited to the United States to testify on foreign cost and production in subsidy cases before the Maritime Administration. From 1957 through 1962 he was associated with several U.S. Naval Architect firms: was Owner's Representative in Europe and Japan conducted studies on transport economy for Venezuela ICC and shipowners and was a consultant for shipyard planning in Brazil and Europe. In 1963 he joined the Staff of the Center for Naval Analysis (CNA) and became Head of the Logistic Section and Study Director. There he originated the FDL ship and ship concept and was assigned as advisor to the Project Manager. From 1968 through 1974 Dr. Frisch was a Faculty member and visiting lecturer at Massachusetts Institute of Technology he lectured on Shipyard Management Ocean Transportation Systems Theory in Transportation and in Interdisciplinary Seminars. In 1972 and 1973 he was consultant to Dubai Drydock. Ltd. for layout of a new shipyard in the Arabian Gulf but since 1973 he has been with the Naval Sea Systems Command mostly involved in special projects. Dr. Frisch is also Adj. Professor for Virginia Polytechnic Institute & State University (VPI) where he teaches graduate courses in Advanced Engineering Economy and Management Concepts. Mr. Charles Toddis a graduate of Howard University School of Engineering Washington D.C where he has also pursued his graduate work. He has fifteen years' experience in New Construction Shipbuilding Acquisition Programs concentrating in the areas of Major Ship Class Project Engineering and Program Management. He worked in this capacity on the LSD 36 and 37 Class ships and in the Special Craft Section of the Combatant Craft

Learning leads to a decrease in program cost and inflation leads to an increase in program cost. At a certain time, the benefits of leaming and the penalty due to inflation will balance each other. This time is defined as the “critical time.” The “critical tune” depends upon the number of ships to be built because this determines the possible gain in learning. The “Critical time” also depends upon the assumed inflation, upon the achievable learning rate, and upon the material/labor ratio of the first ship. Learning expectation can be influenced by planning and the material/labor ration by a make– or buydecision. Assumptions on future learning are as vague as assumptions on inflation. The paper shows that it is almost impossible to beat inflation. It shows that accelerated programs are preferable and that make—decisions supersede the value of buy—decisions. The result is derived from an abstract treatment of the subject. © 1978 American Society of Naval Engineers

关键词：

来源：评论

学校读者我要写书评

暂无评论

Book reviews

引用

Human Ecology 1977年第4期5卷 383-402页

作者： Sussmann, Hector J. Ammerman, Albert J. Hoffpauir, Robert Levandowsky, Michael Ehrenfeld, Joan Shechter, Mordechai Esser, Aristide H. Schuh, Janet C. Department of Mathematics Rutgers University New Brunswick Program in Human Biology Stanford University Stanford Department of Geography California State University Northridge Haskins Laboratories at Pace University New York Center for Coastal and Environmental Studies Rutgers University Piscataway Faculty of Industrial Engineering and Management Technion-Israel Institute of Technology Haifa Israel The Association for the Study of Man-Environment Relations Inc. Orangeburg Department of Human Ecology and Social Sciences Cook College Rutgers University New Brunswick

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：