Summary form only given. We report the room temperature operation of a novel unipolar self-organized quantum dot FIR laser (13.3 /spl mu/m) based on transitions between discrete bound electron states in self-organized...
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Summary form only given. We report the room temperature operation of a novel unipolar self-organized quantum dot FIR laser (13.3 /spl mu/m) based on transitions between discrete bound electron states in self-organized dots. A typical photoluminescence spectrum of InGaAs-GaAs self-organized quantum dots is shown.
In a psychophysical experiment, a wideband, 4-ms noise is compared with spectrally smoothed versions of the noise. To isolate on the magnitude spectrum, the phase spectrum is controlled by assigning the same random ph...
The AlGaN/GaN heterostructure is important for both electronic and optoelectronic devices. In addition to having a large band gap, the heterostructure has a strong piezoelectric effect and a large spontaneous polariza...
The AlGaN/GaN heterostructure is important for both electronic and optoelectronic devices. In addition to having a large band gap, the heterostructure has a strong piezoelectric effect and a large spontaneous polarization. This allows one to incorporate a large electric field (>106 V/cm) and high sheet charge (>1013 cm−2) without doping. Theoretical studies are done to examine how polarization effects controls the sheet charge density. The studies also focus on how interface roughness, aluminum mole fraction in the barrier, impurity scattering, sheet charge density, and phonon scattering influence mobility. Results are compared with experimental studies on samples grown by both molecular beam epitaxy (MBE) and metalorganic chemical vapor deposition (MOCVD). We find that interface roughness is a dominant source of scattering in the samples reported. Due to the variation in growth techniques we find that the MBE samples have a smoother interface quality compared to the MOCVD samples. By carefully fitting the experimental data we present results on interface roughness parameters for MBE and MOCVD samples.
Grasslands are the largest of the Earth's four major vegetation types and are among the most agriculturally productive lands. Grassland management practices alter biophysical factors, such as plant species composi...
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This article introduces the concept of synthetic cultures. These are role profiles for enacting dimensions of national culture. The full profiles are given for 10 synthetic cultures, based on Gert Hofstede's dimen...
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We apply the modal distribution, a high-resolution time-frequency distribution, to the study of sung musical passages. Evidence is presented comparing the modal distribution with the spectrogram for a set of synthetic...
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作者：
Leite, MJMensh, DRMichael J. Leite:is a Principal Engineer with PRC
Inc. a division of Litton Industries. He supports combat system engineering for theater air and missile defense. His other tasks have included the command and control for the AEGIS shipbuilding program systems engineering for the 21st Century Surface Combatant combat system survivability and the development of NATO standardization agreements for naval ordnance. He was previously a Senior Engineer with San Diego Gas & Electric with responsibility for its energy application and lighting programs. Prior to joining SDG&E Mr. Leite was a commissioned officer in the U.S. Navy where he served in operations and engineering assignments. Following active duty he accepted a Naval Reserve commission and has retired with the rank of Captain. His assignments included command operational and engineering tours. Mr. Leite has also served as an expert witness in admiralty and engineering matters. He is a gradate of the University of California Berkeley with a Bachelor of Science Degree in Engineering and also holds a Masters Degree in Business Administration from National University in San Diego. Mr. Leite is a Registered Professional Engineer in the States of California and Minnesota. Mr. Leite is a member of ASNE ASCE MORS the Illuminating Engineering Society and the U.S. Naval institute. Dennis Roy Mensh:is a Senior Engineer with PRC
Inc. a division of Litton Industries in Crystal City VA where he supports modeling and simulation tasking for combat systems. He received BS and MS degrees in applied Physics from Lopola College in Baltimore MD and the American University in Washington DC. He has also completed the course work towards a Ph.D. degree in computer science specializing in the fields of Operations Reseurch Anabsis Systems Analysis and Computer Modeling and Simulation. Previously he was employed at the White Oak Laboratory of the Naval Surface Warfare Carter in Silver Spring MD where he worked in the areas of naval sensor and weapon system analysis
This paper defines, develops and examines a set of generic analysis tools that can be applied to Models and Simulations at the Systems Engineering level of fidelity. The tools examine the performance and effectiveness...
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This paper defines, develops and examines a set of generic analysis tools that can be applied to Models and Simulations at the Systems Engineering level of fidelity. The tools examine the performance and effectiveness of Sensors;Weapons;and Battle Management, Command, Control, Communications, computers, and Intelligence ((BMCI)-I-4) systems and equipment. The Measures of Performance (MOPs), Measures of Effectiveness (MOEs) and Measures of Force Effectiveness (MOFEs) were extracted from the Modular Command and Control Structure Paradigm which was developed at the Naval Postgraduate School. The paradigm provides for the development of evaluation criteria (MOPs, MOEs, and MOFEs) in a framework that ensures the traceability of system performance and effectiveness to the system operational requirements as specified in the Operational Requirements Document (ORD). Also, the analysis tools provide insight and valid estimates of numerical measures of the defined system functionality threads, which represent the system's operational requirements as specified in the ORD. The tools are directly transferrable and applicable to test and evaluation exercise events which are conducted in support of the development and acquisition of systems and equipment. Once the levels of system performance have been defined, the Paradigm generates a quantitative database that becomes a useful tool in system tradeoffs and selection. Once the alternative system suites have been defined, the suites can be analyzed in terms of system functionality threads and their corresponding performance capabilities versus cost.
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 from MA/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.
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