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1991 IEEE Aerospace Applications Conference Digest最新文献

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Systems management of wire and cable 电线电缆系统管理
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154541
T. Scott, N. Riemen
{"title":"Systems management of wire and cable","authors":"T. Scott, N. Riemen","doi":"10.1109/AERO.1991.154541","DOIUrl":"https://doi.org/10.1109/AERO.1991.154541","url":null,"abstract":"The Materials Management System used by Houston Wire & Cable in each of their 12 US warehouses is described. The system is primarily intended for major construction projects. With this system, the wire and cable supplier accepts the tasks of warehousing, quality assurance and quality control, cutting and reeling, overnight shipping, and the elimination of all surplus. The care and custody of the wire and cable are accepted by the supplier. The positive results of this shift of responsibility to the supplier are shown. These include a reduction in purchasing costs, on-time deliveries, reduced storage costs, no cut charges, no minimum lengths, no reel deposits, overnight deliveries, reduction of thefts and damage, accurate quality control and the elimination of surplus. The overall cost reduction using this system was 22% over the life of the project presented.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132090886","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Application of HTSC-thin films in microwave integrated delay lines htsc薄膜在微波集成延迟线中的应用
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154535
A. R. Jha
{"title":"Application of HTSC-thin films in microwave integrated delay lines","authors":"A. R. Jha","doi":"10.1109/AERO.1991.154535","DOIUrl":"https://doi.org/10.1109/AERO.1991.154535","url":null,"abstract":"The author describes the capabilities of high-temperature superconducting thin films (HTSTF) for possible application in microwave integrated delay lines. HTSTF can be characterized as thin-film microstrip (TFMS) lines operating at superconducting temperatures. Low insertion loss, minimum signal delay, and small power dissipation are possible with HTSTF delay lines. The conductor loss, dielectric loss, signal distortion, signal delay, and instantaneous bandwidth are dependent on the film thickness, superconducting film material, and substrate properties. Thin films on yttrium barium copper oxide (YBCO), bismuth strontium calcium copper oxide (BSCCO), and thalium calcium barium copper oxide (TCBCO) appear to be the most suitable for microwave integrated delay lines.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122042112","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
C-band shaped beam hemi/zone antenna c波段形波束半/区天线
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154525
G.H. Schennum, L. Ersoy
{"title":"C-band shaped beam hemi/zone antenna","authors":"G.H. Schennum, L. Ersoy","doi":"10.1109/AERO.1991.154525","DOIUrl":"https://doi.org/10.1109/AERO.1991.154525","url":null,"abstract":"The authors describe, in detail, the design of the Intelsat VII hemi/zone antennas and the measured performance of this pulsed frequency modulation (PFM) hardware relative to the theoretical computer predictions. The hemi/zone C-band communication antennas provide transmission (downlink) in the 3704 to 4073 MHz frequency band and reception (uplink) in the 5929 to 6298 MHz frequency band. The antennas consist of two deployable parabolic offset reflectors, one for the receive band and the other for the transmit band. The good correlation between the measured and computed results substantiates the quality of the hardware design.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127653441","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Structured process flows (SPFs): a process model for metrics 结构化流程流(spf):用于度量的流程模型
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154538
D. Tamanaha
{"title":"Structured process flows (SPFs): a process model for metrics","authors":"D. Tamanaha","doi":"10.1109/AERO.1991.154538","DOIUrl":"https://doi.org/10.1109/AERO.1991.154538","url":null,"abstract":"The author discusses an SPF process flow model that is suitable for communicating process descriptions to a wide audience and that can serve as a platform for metrics for both process and products. Large, complex, distributed command and control systems have been analyzed with a number of coordinated paradigms, including this model. Structured process flows give an integrated overview of systems complementary to the partitioned structure analysis models, as in structured analysis methods for real-time systems. They represent a leveled, end-to-end threaded view of the major processes in a system and provide the necessary first view of the system, while enabling the continuing decomposition for details. The SPFs are examined here as a platform for understanding processes, for exploration of metrics, and as a mechanism for collecting measurements.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122960502","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
A design knowledge support system for Space Station Freedom and beyond? 太空站自由及以后的设计知识支持系统?
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154539
J. Gilbert, E.K. Aisawa
{"title":"A design knowledge support system for Space Station Freedom and beyond?","authors":"J. Gilbert, E.K. Aisawa","doi":"10.1109/AERO.1991.154539","DOIUrl":"https://doi.org/10.1109/AERO.1991.154539","url":null,"abstract":"A design knowledge support systems (DKSS) for Space Station Freedom is discussed which is intended to contribute to the success of the Space Station project by helping engineers refine the design without repeatedly 'reinventing the wheel'. The design knowledge necessary to accomplish this task encompasses what the substance of a design is, how it has evolved to its current configuration, and why it satisfies requirements of the design. Use is made of design knowledge capture (DKC), the process of collecting, analyzing, and maintaining design knowledge in a systematic machine-interpretable form. A DKSS is a set of automated tools that supports the DKC process.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"112 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128989660","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Real time systems/software methodologies for large aerospace systems 大型航空航天系统的实时系统/软件方法
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154537
B. Patel, V. Litchfield, D. Tamanaha, A. Davis
{"title":"Real time systems/software methodologies for large aerospace systems","authors":"B. Patel, V. Litchfield, D. Tamanaha, A. Davis","doi":"10.1109/AERO.1991.154537","DOIUrl":"https://doi.org/10.1109/AERO.1991.154537","url":null,"abstract":"An overview of three proven and two emerging real-time methodologies currently available commercially is presented. The methods are described and compared based on criteria relevant to large aerospace projects. These methods are then compared against a typical US DoD system engineering lifecycle to show where individual projects have to enhance these methods with inhouse concepts to be practical. The study was undertaken by Hughes at Fullerton to determine a standardized way of training its systems/software engineers in a relevant method to increase productivity and quality of design. The authors describe the additional enhancements needed for these methods, and propose future direction for vendors to satisfy aerospace needs. The study recommends PSD (Process for System Development) as an interim baseline methodology upon which to add extensions (e.g. reliability engineering, logistics engineering, etc.) to complete the methodology.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"85 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125103194","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 2
Priority-based scheduling of scarce resources 基于优先级的稀缺资源调度
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154536
M.E. McDowell
{"title":"Priority-based scheduling of scarce resources","authors":"M.E. McDowell","doi":"10.1109/AERO.1991.154536","DOIUrl":"https://doi.org/10.1109/AERO.1991.154536","url":null,"abstract":"In the priority scheduling problem limited resources must be assigned to prioritized jobs of fixed duration. The optimal solution to an instance of the priority scheduling problem assigns resources to as many top priority jobs as possible. The priority scheduling problem is formalized, and it is proved that it is computationally difficult, or NP-hard. An exponential though efficient algorithm which obtains optimal solutions is also proposed. The algorithm is demonstrated on several vexing problems. Finally, modifications to the algorithm which would allow it to obtain 'near optimal' solutions in polynomial time are suggested.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"59 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134126492","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 1
Pattern recognition for nondestructive evaluation 无损评价的模式识别
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154534
M. Amirfathi, S. Morris, P. O'Rorke, W. Bond, D. St. Clair
{"title":"Pattern recognition for nondestructive evaluation","authors":"M. Amirfathi, S. Morris, P. O'Rorke, W. Bond, D. St. Clair","doi":"10.1109/AERO.1991.154534","DOIUrl":"https://doi.org/10.1109/AERO.1991.154534","url":null,"abstract":"The issues involved in automating nondestructive evaluation (NDE) techniques are outlined. Attention is given to research focused on the application of machine learning techniques to the construction and maintenance of knowledge-based systems which are capable of evaluating the readings from nondestructive tests that have been performed on aircraft components. Preliminary results obtained from this research are described. In particular, the authors discuss the application of a symbolic machine learning algorithm, ID3, to the NDE problem. ID3 has been used by Douglas Aircraft to classify defects in sets of standard NDE reference blocks. Based on the preliminary results, a need for an improved method of distinguishing features in the test waveforms is identified. The authors also outline a feature extraction approach from pattern recognition, called scale-space filtering, which can be used to preprocess data for input into a classification algorithm such as ID3.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134479538","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 6
Feed for a four-horn monopulse tracking radar 四角单脉冲跟踪雷达的馈源
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154521
M. Evans, S. Louza, N. Audeh
{"title":"Feed for a four-horn monopulse tracking radar","authors":"M. Evans, S. Louza, N. Audeh","doi":"10.1109/AERO.1991.154521","DOIUrl":"https://doi.org/10.1109/AERO.1991.154521","url":null,"abstract":"A pyramidal horn for a four-horn feed and a perfectly conducting parabolic reflector of circular aperture minimizing the angular tracking error have been considered. A nominal frequency of 10 GHz and a focal length to distance ratio of unity were chosen for purposes of numerical evaluation. The analysis of the pyramidal horn is approached from the sectoral horn approximation which is usually used in practice. Following the analysis of the horn, the aperture distribution is decomposed into the horn eigenfunctions, and the waveguide aperture excitations are found. The monopulse sums and difference signals are then defined, and the variance of their ratio is calculated. From this variance, the root-mean-square angular tracking error is calculated which provides the criterion for the design of the pyramidal horn aperture dimensions.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132739338","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 3
Parametric analysis of an ion propulsion system for performing large inclination changes in low Earth circular orbits 近地圆轨道大倾角变化离子推进系统的参数分析
1991 IEEE Aerospace Applications Conference Digest Pub Date : 1991-02-03 DOI: 10.1109/AERO.1991.154530
B. Jackson, G. Hoffman
{"title":"Parametric analysis of an ion propulsion system for performing large inclination changes in low Earth circular orbits","authors":"B. Jackson, G. Hoffman","doi":"10.1109/AERO.1991.154530","DOIUrl":"https://doi.org/10.1109/AERO.1991.154530","url":null,"abstract":"An analytical model has been constructed for an ion propulsion system which performs large changes in the inclination of a satellite in low-earth orbit. A thrusting strategy and the top-level propulsion system design are also presented. The analytical model enables the derivation of requirements for Delta V, propellant, and power. A parametric trade study is presented which explores the relationship of duty cycle and specific impulse to power and propellant requirements. The primary result of this study is a determination of which propulsion system parameters have the greatest effect on overall system performance. It is found that the power processing unit design is the main driver in determining available satellite payload.<<ETX>>","PeriodicalId":158617,"journal":{"name":"1991 IEEE Aerospace Applications Conference Digest","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1991-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133597361","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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