检索结果-内蒙古大学图书馆

IEEE Conference on Decision and Control

作者： N. Levy MengChu Zhou Yu Quan Department of Mechanical and Industrical Engineering New Jersey Institute of Technology Newark NJ USA Department of Electrical and Computer Engineering New Jersey Institute of Technology Newark NJ USA Manufacturing Engineering Program New Jersey Institute of Technology Newark NJ USA

Real-time identification of tool wear in shop floor environment is essential for optimization of machining processes and implementation of automated manufacturing systems. In this paper. the signals obtained from acoustic emission and power sensors during machining processes are analyzed and a set of feature parameters characterizing the tool wear condition are extracted. In order to realize the realtime tool wear condition monitoring for different cutting conditions, a sensor integration strategy which combines the information from multiple sensors (acoustic emission sensor and power sensor) and machining parameters is proposed. A neural network based on improved back-propogation algorithm is developed and a prototype scheme for realtime identification of tool wear is implemented. Experiments under different conditions have proved that a higher rate of tool wear identification can be achieved by using the sensor integration model with neural network. The results also indicated that the neural network is a very effective method of sensor integration for online monitoring of tool abnormalities.< >

关键词： Wearable sensors Sensor phenomena and characterization Acoustic sensors Machining Neural networks Acoustic emission Real time systems Manufacturing systems Signal processing Signal analysis

来源：评论

学校读者我要写书评

暂无评论

Multimode behavior of a vertical-cavity surface-emitting laser with feedback from an external reflecting surface

Multimode behavior of a vertical-cavity surface-emitting las...

引用

IEEE Photonics Conference (IPC)

作者： S. Jiang M. Dagenais R.A. Morgan Department of Electrical Engineering and Joint Program for Advanced Electronic Material University of Maryland College Park MD USA Department of Electrical Engineering and Joint Program for Advanced Electronic Materials University of Maryland College Park MD USA Honeywell Technology Center Lyndale Avenue South Bloomington MN USA

Vertical-cavity surface-emitting lasers (VCSELs) present many advantages over conventional edge-emitting lasers because of their unique structure. One of the most attractive properties of VCSELs is their single-longitudinal-mode operation due to their very short cavity. On the other hand, it is well known that a conventional edge-emitting semiconductor laser may exhibit many compound-cavity modes when it operates with external optical feedback. The purpose of this paper is to investigate the spectral characteristics of a VCSEL in the presence of optical feedback from an external reflecting mirror.

关键词： Vertical cavity surface emitting lasers Laser feedback Surface emitting lasers Optical feedback Laser modes Semiconductor lasers Mirrors Laser theory Optical attenuators Laser beams

来源：评论

学校读者我要写书评

暂无评论

Optical spectrum sidebands of a vertical-cavity surface-emitting laser

Optical spectrum sidebands of a vertical-cavity surface-emit...

引用

IEEE Photonics Conference (IPC)

作者： S. Jiang M. Dagenais R.A. Morgan Department of Electrical Engineering and Joint Program for Advanced Electronic Materials University of Maryland College Park MD USA Honeywell Technology Center Bloomington MN USA

Important information about the high-speed operation of semiconductor lasers can be extracted from a study of their noise spectral properties. The optical spectrum of a semiconductor laser consists of a main central peak surrounded by sidebands detuned from the main peak by the laser relaxation oscillation frequency. In this paper, we present a detailed study of the optical spectrum of vertical-cavity surface-emitting lasers (VCSELs).

关键词： Vertical cavity surface emitting lasers Surface emitting lasers Optical feedback Optical filters Optical interferometry Semiconductor lasers High speed optical techniques Frequency Laser noise Optical surface waves

来源：评论

学校读者我要写书评

暂无评论

CONTRAROTATING ELECTRIC DRIVE FOR ATTACK SUBMARINES

引用

NAVAL ENGINEERS JOURNAL 1994年第2期106卷 45-50页

作者： DUTTON, JL The Author:is an electrical engineer with NNS ‘s advanced propulsion technology department. This group applies current and future technologies to naval and marine propulsion plant designs. Dutton received his BS degree in electrical engineering from the University of Virginia in 1978 and began working at NNS later that year. His previous tasks have included the AN/BSY-2 Combat System in the NNS Seawolf program and project leader of the NNS superconductivity program. An officer of the Cryogenic Society of America (Hampton Roads Chapter) he is presently working on advanced motor/generator designs and electrical distribution systems for shipboard applications at NNS.

This paper addresses certain issues relating to the viability of contrarotating (CR) electric drive for attack submarines. Topics include CR propulsion's potential benefits, electric drive advantages, and combining contrarotation with electric drive engine room concepts. CR propellers provide propulsive coefficient (PC) increases compared to open-type and performance-enhanced single propellers. The maximum submarine propulsion plant power capacity could therefore be reduced with this PC increase, potentially resulting in a smaller, lighter propulsion plant. This paper concludes, however, that contrarotation shows no propulsion plant weight savings against electric drive attack submarines with performance-enhanced single propeller designs. Weight improvements in the power generation plant and certain steam plant and electric plant systems are offset by weight increases from the additional shafting and bearing requirments for the CR shaft. Contrarotation is currently more advantageous for nonnuclear ships, where significant fuel savings are achievable with its higher PC.

关键词：

来源：评论

学校读者我要写书评

暂无评论

ACQUISITION REFORM AND BEST PRODUCT PROCUREMENT - AN engineering VIEW

引用

NAVAL ENGINEERS JOURNAL 1994年第6期106卷 41-57页

作者： FISHER, DA SKOLNICK, A He has been involved with several weapon system developments. Among these were the Trident II fire control and navigation systems the BSY-I Anti-Submarine Warfare System and the Navy standard computers (UYK44 and EMSP). He served as manager of the Digital Circuits Engineering Branch and was then appointed as manager of the Automatic Test Equipment (ATE) Technology Division. As manager of the ATE Technology Division he was responsible for the SP-23 Fire Control System Support Project the SP-24 Navigation Project and the Fleet Progressive Maintenance Program (2M/ATE). This Division was responsible for selection and application of electronic product technology and for developing fleet test and repair techniques. He holds a B.S. in Electrical Engineering from the University of Evansville and is currently pursuing a Masters of Public Administration at Indiana University-Purdue University Indianapolis. Dr. Alfred Skolnick:retired from the Navy in 1983 with the rank of captain. He is president of System Science Consultants (SSC) specializing in strategic planning technical program definition technology assessment and engineering analyses on selected matters of national interest. Dr. Skolnick taught mathematics and management sciences at University of Virginia and Marymount University. He is adjunct faculty at Northern Virginia Community College. From 1985 to 1989 he was president of the American Society of Naval Engineers. In the Navy he served at Applied Physics Laboratory/The Johns Hopkins University then aboard USSBoston(CAG-1) and played leading roles in several weapon system developments inertial navigation (Polaris) deep submergence (DSRV) and advanced ship designs (SES). He later was director Combat System Integration Naval Sea Systems Command and head Combat Projects Naval Ship Engineering Center. In 1975 he became a major project manager and led the Navy's High Energy Lasers Program in 1981 he was assigned all Navy Directed Energy Weapons development efforts. He was vice president advanced tech

The military services are being moved in the direction of performance-based specifications and standards. They are being steered against dictating ''how to'' produce an item since such action forecloses on the ability to gain access to components or technology that may have a commercial equivalent. Why should the engineering community embrace the new approach? Aside from the obvious weight of it being approved policy, therefore currently mandated, it warrants examination because it is the correct approach at this time when applied to appropriate products. Military specifications and standards are to be displaced then, by acceptable alternative contractor design solutions. Industry bidders will be allowed to propose the particular design details, permitting procurement flexibility by contractually citing only system level or interface requirements, both physical and functional. Hopefully, this can broaden the industrial base and increase competition with reduced costs to follow. Conceptually, the approach appears both performance-sensible and cost-attractive (there are, of course, consequent risks) but how does implementation proceed? Is it possible to pursue the goals envisioned along paths that are not in themselves experimental? Can the American postulate, minimal loss of life and limb to U.S. military people, continue to be honored? Experience and track record elsewhere imply encouraging possibilities in select situations-useful prospects are identified and discussed in practical terms.

关键词：

来源：评论

学校读者我要写书评

暂无评论

TECHNICAL ISSUES REGARDING SATELLITE PACKET-SWITCHING

引用

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第3期12卷 257-267页

作者： IVANCIC, WD CHU, P SHYY, DJ National Aeronautics and Space Administration Lewis Research Center Cleveland Ohio 44135 USA. A design engineer in the Digital Technology Branch of the Space Electronics Division. He has extensive experience in satellite communications systems modulation and coding on-board switching and routeing and high speed digital design. Since joining NASA in 1982 Mr. Ivancic has been responsible for the development of a variety of matrix switch controllers ground terminal equipment numerous pieces of special test equipment a beacon controller for the SARSAT program (Search and Rescue Satellite) and a time-shared decoder for a processing satellite. In addition Mr. Ivancic has been technical contract monitor on a number of advanced communications technology contracts including the Advanced Modulation Technology Development a 5 GHz fibre-optic link and multi-programmable modem study. He was awarded the B.S.E.E. and M.S.E.E. degrees by Cleveland State University in 1982 and 1986 respectively. Cleveland State University Cleveland Ohio 44115 USA. Currently an assistant professor of Electrical Engineering Department at Cleveland State University. He obtained the M.S. and Ph.D. degrees from Iowa State University majoring in Electrical and Computer Engineering. His research interests include high-speed computer networks digital systems and neural networks applications. He is a member of Sigma Xi Phi Kappa Phi as well as the IEEE and ACM. ComSearch Reston Virginia 22091 USA. Received the B.S. degree in electrical engineering from National Chiao-Tung University Hsin-Chu Taiwan in 1983 and the M.S. and Ph.D. degrees in electrical engineering from Georgia Institute of Technology Atlanta GA in 1986 and 1990 respectively. From June 1987 to October 1987 he worked for the Department of Neurology Emory University Atlanta as a Programmer. From September 1989 to December 1989 he worked for the Advanced Development Laboratory. AMP Inc. Atlanta as a Test Engineer. From February 1990 to August 1993 he wor

Many concepts for advanced communication satellite networks have recently been proposed. Critical technical issues relating to satellite packet switching for meshed very small aperture terminal networks and broadband ... 详细信息

关键词： FAST PACKET SWITCH BISDN MESHED VSAT ON-BOARD PROCESSING

来源：评论

学校读者我要写书评

暂无评论

AN ARCHITECTURE DESIGN APPROACH FOR LARGE SATELLITE NETWORKS

引用

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第3期12卷 197-210页

作者： COTNER, C INUKAI, T COMSAT World Systems 6560 Rock Spring Drive Bethesda MD 20817 USA. Director Customer Technical Support for COMSAT World Systems. He directs support to U.S. users of the INTELSAT satellite network particularly in the areas of certifying that performance of earth-stations is in accordance with system requirements and in supporting the unique needs of television customers. Mr. Cotner's primary technical interests are earth-station design transmission analysis and high power amplifiers. Mr. Cotner has been with COMSAT for over 25 years. Most recently he served as Director of Technical Liaison and Analysis responsible for much of COMSAT World Systems research and development programme for high-level technical interaction with customers such as AT&T and MCI and for initiatives to improve the quality of international satellite transmission. He has also held technical management positions in COMSAT Laboratories COMSAT General where he was a Division Director Earth Segment Engineering and COMSAT World Systems where he represented the U.S. Signatory on the INTELSAT Board of Governors Technical Advisory Committee for five years. Mr. Cotner is a colonel (retired) in the Signal Corps U.S. Army Reserve where he was assigned to several mobilization positions related to satellite communications including a tour of duty on the Joint Staff. Awarded the degree of B.S.E. (cum-laude) in Electrical Engineering by Princeton University. Mr. Cotner also holds an M.S.E. from Cornell University and is a Commandants List graduate of the U.S. Army Command and General Staff College. He and his wife Sharon live in Silver Spring Maryland. COMSAT Laboratories 22300 COMSAT Drive Clarksburg MD 20871 USA. Received the BS and MS degrees in Communications Engineering from the Tokyo Electrical Engineering College Tokyo Japan and the Ph.D. degree in Electrical Engineering from the City University of New York New York. Dr. Inukai is a Principal Scientist in the Network Technology Division of COMSAT Laboratories. He directs res

Designing a world-wide satellite network that consists of hundreds of user sites and thousands of circuit connections is a complex problem, which involves selecting a set of candidate satellites and satellite beams/frequency bands from among numerous existing and planned satellites, evaluation of circuit connectivity, earth-station compatibility and sizing, and estimating transponder loading. The design process may also require assessment of the impact of a different set of satellites and modified user traffic requirements on the space segment, the earth-station types and quantity, and the total system cost. Although a conventional design approach based on link-by-link and site-by-site analysis provides accurate results, it is time-consuming and impractical for developing high-level network architectures in a time-constrained environment. A design technique is proposed which employs a set of rules for satellite network design, in combination with extensive databases of satellite parameters, earth-station parameters and user traffic requirements, to synthesize a network architecture. The technique is particularly useful for performing high-level trade-offs among alternative architectures in terms of space segment requirements, the number and type of earth-stations and overall system cost. Once the desired architecture has been selected, a detailed design may be developed using conventional methods.

关键词： SATELLITE NETWORK DESIGN RULE-BASED DESIGN FIXED SATELLITE SERVICES FDMA INTELSAT BANDWIDTH REQUIREMENTS TRANSPONDER CAPACITY

来源：评论

学校读者我要写书评

暂无评论

ANALYSIS OF A MOVABLE BOUNDARY ACCESS TECHNIQUE FOR A MULTISERVICE MULTIBEAM SATELLITE SYSTEM

引用

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第3期12卷 299-312页

作者： BOHM, S ELHAKEEM, AK MURTHY, KMS HACHICHA, M KADOCH, M Department of Electrical and Computer Engineering Concordia University 1455 De Maisonneuve Blvd. West Montreal H3A 1M8 Canada Was born in Montreal Canada on 14 September 1966. He received the B. Eng. degree in electrical engineering from Concordia University Montreal Canada in 1989. He is at present completing the M.A.Sc. degree in electrical engineering at Concordia University. (S'75–S'79–M'79–SM'86) received the Ph.D. degree from Southern Methodist University Dallas TX in 1979. He spent the next two years working as a Visiting Professor in Egypt after which he moved to Ottawa Canada in 1982. He assumed teaching and research positions in Carleton and Manitoba Univerities and later moved to Concordia University Montreal Canada in 1983 where he is now a Professor in the Electrical and Computer Engineering Department. He has published numerous papers in IEEE and international journals in the areas of spread spectrum and networking. He is a well-known expert in these areas and serves as a consultant to many companies. His current research interests include wide-band metropolitan networks switching architectures and performance of on-board multibeam satellites acquisitionless CDMA networks code distribution and orthogonalization of CDMA signals responsive congestion control for ATM-based networks ARQ techniques and investigation of the novel SUGAR CDMA systems in fading channels. Dr. Elhakeem is a Senior Member of the Canadian Electrical Engineering Society and Armed Forces Association. He has chaired numerous technical sessions in IEEE Conferences was the Technical Program Chairman for IEEE Montech 1986 Montreal Canada. Dr. Elhakeem is the key guest editor of theIEEE Journal of Selected Areas in Communicationsfor the May June issues 1993 covering CDMA networks. Advanced Technology & Networks VISTAR Telecommunications Inc. Ottawa Ontario K1G 3J4 Canada . He is ITU's Specialist Consultant and Chief Advisor for a number of ITU/UNDP projects including VSATs Rural Networks Digital Broadc

In this paper, the performance of a new movable boundary accessing (MBA) technique for future integrated services multibeam satellite systems is studied. The multiservice environment considered includes both asynchronous and isochronous traffic consisting of video, voice, file transfer and interactive data. The movable boundary access technique proposed here will maximize the utilization of the up-link frame capacity. It is shown that the potential user population is substantially increased with the use of a moving boundary policy with minimal overhead.

关键词： MOVABLE BOUNDARY ACCESS TECHNIQUE MF-TDMA DAMA MULTIBEAM SATELLITE

来源：评论

学校读者我要写书评

暂无评论

PERFORMANCE OF A PRIORITIZED ON-BOARD BASEBAND SWITCH FOR A MULTISERVICE MULTIBEAM SATELLITE

引用

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第3期12卷 283-297页

作者： BOHM, S ELHAKEEM, AK HACHICHA, M Department of Electrical and Computer Engineering Concordia University 1455 De Maisonneuve Blvd. West Montreal H3A 1M8 Canada Was born in Montreal Canada on 14 September 1966. He received the B. Eng. degree in electrical engineering from Concordia University Montreal Canada in 1989. He is at present completing the M.A.Sc. degree in electrical engineering at Concordia University. (S'75–S'79–M'79–SM'86) received the Ph.D. degree from Southern Methodist University Dallas TX in 1979. He spent the next two years working as a Visiting Professor in Egypt after which he moved to Ottawa Canada in 1982. He assumed teaching and research positions in Carleton and Manitoba Univerities and later moved to Concordia University Montreal Canada in 1983 where he is now a Professor in the Electrical and Computer Engineering Department. He has published numerous papers in IEEE and international journals in the areas of spread spectrum and networking. He is a well-known expert in these areas and serves as a consultant to many companies. His current research interests include wide-band metropolitan networks switching architectures and performance of on-board multibeam satellites acquisitionless CDMA networks code distribution and orthogonalization of CDMA signals responsive congestion control for ATM-based networks ARQ techniques and investigation of the novel SUGAR CDMA systems in fading channels. Dr. Elhakeem is a Senior Member of the Canadian Electrical Engineering Society and Armed Forces Association. He has chaired numerous technical sessions in IEEE Conferences was the Technical Program Chairman for IEEE Montech 1986 Montreal Canada. Dr. Elhakeem is the key guest editor of theIEEE Journal of Selected Areas in Communicationsfor the May June issues 1993 covering CDMA networks. Advanced Technology & Networks VISTAR Telecommunications Inc. Ottawa Ontario K1G 3J4 Canada An Associate Director of Advanced Technology & Networks Group VISTAR Telecommunications Inc. Ottawa Canada. He is also an Adjunct Pr

In this paper, we study the performance of a prioritized on-board baseband switch in conjunction with a multibeam satellite handling integrated services. The services considered for the analysis include voice, video, file transfer and interactive data. The prioritized switch uses both input and output buffering, switch speed-up as well as a two-phase head-of-line resolution algorithm, in order to reduce the buffer loss while maintaining acceptable user delays. The minimum required buffer capacity and switch speed-up for each service in a prioritized environment are found under uniform traffic conditions. It is shown that under uniform traffic conditions, only minimal buffering and switch speed-up are needed even for the lowest priority users. The performance dependence on the switch size is also substantially reduced with head of line resolution and buffering even in a prioritized environment.

关键词： SWITCH ON-BOARD BASEBAND MULTIBEAM PRIORITIZED HEAD-OF-LINE UNIFORM LOAD SPEED-UP

来源：评论

学校读者我要写书评

暂无评论

HYBRID SATELLITE AND TERRESTRIAL NETWORKS

引用

INTERNATIONAL JOURNAL OF SATELLITE COMMUNICATIONS 1994年第3期12卷 313-327页

作者： CHITRE, DM SHYY, DJ EPHREMIDES, A GUPTA, S COMSAT Laboratories 22300 Comsat Drive Clarksburg MD 20871–9475 USA. Received his B.Sc. from the University of Bombay India an M.A. in mathematics from the University of Cambridge U.K. and a Ph.D. in physics from the University of Maryland. He is currently an Associate Executive Director of the Network Technology Division at COMSAT Laboratories. He has been involved in research and development activities in ISDN VSAT networks data communications and network systems and architectures. Prior to his current positions Dr. Chitre was a Principal Scientist in the Network Technology Division at COMSAT Laboratories. Dr. Chitre joined COMSAT Laboratories in 1980. He has made major contributions to the analysis and architecture of data communication ISDN and BISDN via satellite. Dr. Chitre directs and participates in the international and national standards activities in ISDN BISDN and data communication as they apply to satellite communication. He was Chairman of the Working Group on Protocols and Network Timing Function of the CCIR/CCITT Joint Ad Hoc Group on ISDN/Satellite Matters during 1990–1992. Currently he is the Chairman of the Working Group on New Technologies in the ITU Intersector Coordinating Group (ICG) on Satellite Matters. Dr. Chitre was a programme manager during 1990 and 1991 on a contract from INTELSAT on systems studies on satellite communications systems architectures for ISDN and broadband ISDN systems. Currently he is the technical manager of the DoD Contract on ATM via satellite demonstration and the programme manager for the INTELSAT contract on analysis and top-level specification of INTELSAT ISDN subnetworks and SDH compatible transport network. Received the B.S. degree in electrical engineering from national Chiao-Tung University Hsin-Chu Taiwan in 1983 and the M.S. and Ph.D. degrees in electrical engineering from Georgia Institute of Technology Atlanta GA in 1986 and 1990 respectively. From June 1987 to October 1987 he worked for the Department of Neurology Emory Univers

The role of satellite communications in networks that provide new services, such as frame relay and multimedia, is investigated. Both passive and active (on-board switching/processing) satellite systems are considered. Novel techniques are developed for each system to demonstrate, via detailed analysis and simulation, how the communications bandwidth agility of multipoint/broadcast satellite channels, and the on-board switching/processing, makes it feasible to provide these new services via hybrid satellite and terrestrial networks in a resource-efficient manner.

关键词： HYBRID NETWORKS ON-BOARD PROCESSING FRAME RELAY

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：