作者：
De Luca, Carlo J.Boston Univ
Neuromuscular Research Cent MA USA Boston Univ Neuromuscular Research Cent MA USA
A history of neuromuscular system biomedical engineering is presented. Developments in the 18th, 19th, and 20th century are chronicled. Progress in the last two decades is highlighted withthe use of selected examples...
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A history of neuromuscular system biomedical engineering is presented. Developments in the 18th, 19th, and 20th century are chronicled. Progress in the last two decades is highlighted withthe use of selected examples grouped in five major areas: signal detection, signal processing, modeling, bioelectric control, and electrical stimulation. Comments on the current status and future of neuromuscular system bioengineers are included in the presentation.
optimization of the design parameters was achieved in three stages. In the first, which involved selection of the optimization criterion, the minimization of the life-cycle cost of the system was chosen. In the second...
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ISBN:
(纸本)0898837251
optimization of the design parameters was achieved in three stages. In the first, which involved selection of the optimization criterion, the minimization of the life-cycle cost of the system was chosen. In the second stage, calculation of the thermal performance of the system was evaluated either with a simulation model or withthe f-charts method. In the third state stage, which involved the optimization method, the Box algorithm, a multivariate direct search method, was used. A general-purpose computer program called SIMENO was developed. SIMENO can be used either for simulation of a given solar system, or for a precise determination of the optimal design parameters of the system. SIMENO includes new system models and an improved computational code for the solar system designer.
作者：
Castles, Stephen H.NASA
Goddard Space Flight Cent Greenbelt MD USA NASA Goddard Space Flight Cent Greenbelt MD USA
the Cosmic Background Explorer (COBE) dewar will be the second long lifetime liquid helium dewar to be used in space. the design of the COBE dewar is based on the design of the dewar used on the Infrared Astronomy Sat...
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the Cosmic Background Explorer (COBE) dewar will be the second long lifetime liquid helium dewar to be used in space. the design of the COBE dewar is based on the design of the dewar used on the Infrared Astronomy Satellite (IRAS) which was launched in 1983. the COBE dewar incorporates a number of design changes to meet shuttle safety and operational requirements, to accomodate the COBE instrument package, to increase lifetime, to lower the operating temperature, to decrease particulate contamination and to improve functional reliability. the fabrication of the COBE dewar was completed in April, 1985. Extensive analytical modeling and in-process testing indicates that the dewar will meet its mission imposed requirements. It is anticipated that the on-orbit lifetime will be approximately 14 months and that the temperature of the cryogen tank will be 1. 45K.
Nonlinear optimization techniques are used to quantify the impact of adding a space fuel inn station and reusable tug to the Space Transportation system (STS). the Shuttle deploys all space traffic to the station at w...
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Defensive Technology Studies have identified several concepts for interceptors which will counter the threat of hostile reentry vehicles. Hypersonic interceptors operating in the sensible atmosphere are one of the mor...
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Defensive Technology Studies have identified several concepts for interceptors which will counter the threat of hostile reentry vehicles. Hypersonic interceptors operating in the sensible atmosphere are one of the more promising near-term options. In such a system, thermal protection of missile’s control systems and the dynamic response of the airframe are key development issues. Jet Interaction Control systems provide viable solutions to both concerns. Aerojet is currently validating the capabilities of JI Control systems for the Army’s Ballistic Missile Defense systems Command. this program has demonstrated the transient and frequency response of pitch, yaw, and roll control thrusters which have exhibited response, thrust modulation, and durability characteristics needed for hypersonic missiles. All design and development efforts were guided by analytical simulations of the response and dynamics of key components and the entire control system. the technology program was structured to address specific control requirements which were determined by detailed missile engagement computer simulations performed by McDonnell Douglas Astronautics Company, the Prime contractor. An integral part of these simulations was the synthesis of the control thruster dynamic behavior to a given command. Because of this dynamic response requirement and the attendant need to structure the design selection process, a detailed, mechanistic, twelve-degree-of-freedom engine response computer model was created. this model was utilized for the simulation, design, and test data analysis of the control thrusters. A fluid dynamics computer model was also established to mechanistically model the dynamic behavior of the pressurization, propellant tankage, and propellant distribution subsystems which are critical to the capabilities of the control engines. this model determines the activation time of the entire system to the first command and was used to evaluate the interactions of the propulsion s
An integral part of these simulations was the synthesis of the control thruster dynamic behavior to a given command. Because of this dynamic response requirement and the attendant need to structure the design selectio...
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An integral part of these simulations was the synthesis of the control thruster dynamic behavior to a given command. Because of this dynamic response requirement and the attendant need to structure the design selection process, a detailed, mechanistic, twelve-degree-of-freedom engine response computer model was created. this model was utilized for the simulation, design, and test data analysis of the control thrusters. A fluid dynamics computer model was also established to mechanistically model the dynamic behavior of the pressurization, propellant tankage, and propellant distribution subsystems which are critical to the capabilities of the control engines. this model determines the activation time of the entire system to the first command and was used to evaluate the interactions of the propulsion system components and their influence on control engines' behavior.
the use of both chemically and ion propelled tugs are evaluated. Applying vector optimization to the latter minimizes boththe average tug flight time and annual Shuttle launches. the resulting efficient operating fro...
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the use of both chemically and ion propelled tugs are evaluated. Applying vector optimization to the latter minimizes boththe average tug flight time and annual Shuttle launches. the resulting efficient operating frontier specifies a set of optimal inclinations, altitudes and tug sizes. the Shuttle launch rates for the chemical and ion systems are potentially less than for current STS projections. Equally important, for existing ion thruster technology the round trip flight time of the tug to geosynchronous orbit can be less than 60 days.
this paper establishes a thermodynamic basis for reducing boiloff losses in cryogenic systems. Implementation of the second law of thermodynamics shows the proportionality between boiloff and entropy production (therm...
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ISBN:
(纸本)0915928752
this paper establishes a thermodynamic basis for reducing boiloff losses in cryogenic systems. Implementation of the second law of thermodynamics shows the proportionality between boiloff and entropy production (thermodynamic irreversibility). the method minimizes entropy production and boiloff by optimizing the location, temperature, and number of cooling stations in the system.
A systemthat automates Programmable Logic Array optimization and synthesis for VLSI design is described. PLA logic is defined via a high level Hardware Definition Language. After translation to table representation c...
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A systemthat automates Programmable Logic Array optimization and synthesis for VLSI design is described. PLA logic is defined via a high level Hardware Definition Language. After translation to table representation comes the logic optimization phase, carried out according to a user defined optimization criterion. the geometrical optimization phase follows, supplemented by a manual interactive graphic PLA editor. the system outputs symbolic Layout of the PLA which can be translated into polygon-level layout.
For the fast growing CAD/CAM technologies, geometric solid modeling plays one of the most important roles. In order to satisfy a variety of engineering applications, an integrated database management system based on s...
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ISBN:
(纸本)9780818600265
For the fast growing CAD/CAM technologies, geometric solid modeling plays one of the most important roles. In order to satisfy a variety of engineering applications, an integrated database management system based on solid modeling is highly desirable. In the proposed approach, a concise object representation scheme, Constructive Solid Geometry (CSG), is adopted as the basis for database design. the underlying generic relational model is found to be more adequate than the conventional relational model in characterizing the embedded data abstraction. A systematic method is devised for converting the CSG scheme into a generic model based on the BNF grammar which depicts the CSG scheme. A relational query language, SEQUEL, has been modified to define, control, and manipulate the flat relations which represent the highly structural generic model.
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