Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673344
R.A. Brown, R. Roeder
Satellite scatterometer (microwave radar) normalized radar backscatter measurements (/spl sigma//sup 0/) can be used to infer near-surface ocean wind speed and direction. The feasibility of scatterometer wind speed remote sensing was first proven with RADSCAT on SKYLAB in 1973. The technique was refined with the Seasat scatterometer in 1978 and work in the early 1990s by European and US space agencies has provided the foundation for continuous, global wind vector measurements. This paper discusses the need for improved scatterometer spatial resolution and the design evolution for planned future high resolution spaceborne scatterometers.
{"title":"Evolution of high spatial resolution spaceborne scatterometers","authors":"R.A. Brown, R. Roeder","doi":"10.1109/SECON.1998.673344","DOIUrl":"https://doi.org/10.1109/SECON.1998.673344","url":null,"abstract":"Satellite scatterometer (microwave radar) normalized radar backscatter measurements (/spl sigma//sup 0/) can be used to infer near-surface ocean wind speed and direction. The feasibility of scatterometer wind speed remote sensing was first proven with RADSCAT on SKYLAB in 1973. The technique was refined with the Seasat scatterometer in 1978 and work in the early 1990s by European and US space agencies has provided the foundation for continuous, global wind vector measurements. This paper discusses the need for improved scatterometer spatial resolution and the design evolution for planned future high resolution spaceborne scatterometers.","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130348150","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}
Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673316
O.M. Ba Rukab, M. M. Shahsavari
An itinerant agent is an agent (object) which can roam the Internet in a secure way and which does useful work for the user. The framework allows the agent and the agent's location to mutually authenticate each other. The developed agent infrastructure provides a way to a survivable intelligent agent that can relieve the agent's owner from worrying about illegal access to distributed databases. This infrastructure provides a general-purpose framework that is usable on the Internet. This agent framework incorporates security measures on both the agent and the agent's location. Java and CORBA languages are used, since Java provides the object with mobility and CORBA provides interoperability for the service afforded by each agent location for agents written in different languages.
{"title":"Survivable itinerant object","authors":"O.M. Ba Rukab, M. M. Shahsavari","doi":"10.1109/SECON.1998.673316","DOIUrl":"https://doi.org/10.1109/SECON.1998.673316","url":null,"abstract":"An itinerant agent is an agent (object) which can roam the Internet in a secure way and which does useful work for the user. The framework allows the agent and the agent's location to mutually authenticate each other. The developed agent infrastructure provides a way to a survivable intelligent agent that can relieve the agent's owner from worrying about illegal access to distributed databases. This infrastructure provides a general-purpose framework that is usable on the Internet. This agent framework incorporates security measures on both the agent and the agent's location. Java and CORBA languages are used, since Java provides the object with mobility and CORBA provides interoperability for the service afforded by each agent location for agents written in different languages.","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123666641","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}
Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673317
Jiling Song, J. Yuan
The excess electron barrier height at high current densities is examined. The barrier effects on the collector current, transconductance as well as base-collector junction capacitance are calculated. The analytical results are compared with the experimental data and device simulation results. Temperature-dependent characteristics are also evaluated.
{"title":"Base-collector heterojunction barrier effects at high current densities of Si/SiGe/Si heterojunction bipolar transistors","authors":"Jiling Song, J. Yuan","doi":"10.1109/SECON.1998.673317","DOIUrl":"https://doi.org/10.1109/SECON.1998.673317","url":null,"abstract":"The excess electron barrier height at high current densities is examined. The barrier effects on the collector current, transconductance as well as base-collector junction capacitance are calculated. The analytical results are compared with the experimental data and device simulation results. Temperature-dependent characteristics are also evaluated.","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123816613","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}
Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673309
M. A. Fares, S. C. Fares, C.A. Ventrice
Based on the laser Doppler anemometry technique and Mie scattering theory, the visibility using a circularly polarized backscattered laser beam was derived and computed. A computer model was developed to establish a relationship between the visibility and the particle size. Experimental data are obtained for comparison with the theoretical results for latex particles of known sizes (0.46 /spl mu/m, 0.74 /spl mu/m, 0.9 /spl mu/m, 1.04 /spl mu/m, 2.02 /spl mu/m, and 2.91 /spl mu/m). Various visibility values associated with various signals are obtained for each particle. Preliminary results establish that these experimental data follow the same trend as the theoretical results (visibility versus diameter).
{"title":"Theoretical data and experimental measurements comparison of the visibility of latex particles using LDA technique in the backscatter direction","authors":"M. A. Fares, S. C. Fares, C.A. Ventrice","doi":"10.1109/SECON.1998.673309","DOIUrl":"https://doi.org/10.1109/SECON.1998.673309","url":null,"abstract":"Based on the laser Doppler anemometry technique and Mie scattering theory, the visibility using a circularly polarized backscattered laser beam was derived and computed. A computer model was developed to establish a relationship between the visibility and the particle size. Experimental data are obtained for comparison with the theoretical results for latex particles of known sizes (0.46 /spl mu/m, 0.74 /spl mu/m, 0.9 /spl mu/m, 1.04 /spl mu/m, 2.02 /spl mu/m, and 2.91 /spl mu/m). Various visibility values associated with various signals are obtained for each particle. Preliminary results establish that these experimental data follow the same trend as the theoretical results (visibility versus diameter).","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127146436","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}
Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673355
Mark R. Nusekabel
The performance of a local area network (LAN) can be improved in many cases by the installation of LAN switches. Determining how to partition a LAN and estimating the performance improvements from a given partitioning are difficult problems. An objective function is developed to quantify a partitioning of a LAN based on a tree-structured topology as supported by IEEE 802.1d compliant LAN switches. It is shown that the objective function developed and the use of tabu search metaheuristic results in a method that finds better partitionings and does so faster than existing methods.
{"title":"Using tabu search to find optimal switched LAN configurations","authors":"Mark R. Nusekabel","doi":"10.1109/SECON.1998.673355","DOIUrl":"https://doi.org/10.1109/SECON.1998.673355","url":null,"abstract":"The performance of a local area network (LAN) can be improved in many cases by the installation of LAN switches. Determining how to partition a LAN and estimating the performance improvements from a given partitioning are difficult problems. An objective function is developed to quantify a partitioning of a LAN based on a tree-structured topology as supported by IEEE 802.1d compliant LAN switches. It is shown that the objective function developed and the use of tabu search metaheuristic results in a method that finds better partitionings and does so faster than existing methods.","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116515016","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}
Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673369
J. Meza, A. Samra
Three-phase bridge rectifiers are widely used in industry to interface DC loads to the electric utility because of their low ripple content output and high power-handling capability. The nonlinear nature of the diode type switching devices causes significant line-current harmonics resulting in increased distortion, malfunction of sensitive electronic equipment, increased losses, and contributes to inefficient use of electric energy. This paper describes a new approach to reduce those line-current harmonics generated by a three-phase diode rectifier type utility interface. The proposed approach consists of a novel interconnection of a delta-zig zag transformer between the AC and DC sides of the diode rectifier topology. This transformer connection in combination with the conduction intervals of each diode generates automatically a circulating third harmonic current between the AC and DC side of the rectifier bridge. Voltage and current analysis and simulation using the Electro-Magnetic Transients Program (EMTP) showed that the generated circulating current may drastically reduce the line current harmonics of the AC side and smooth out the DC output voltage of the rectifier.
{"title":"A new technique to reduce line-current harmonics generated by a three-phase bridge rectifier","authors":"J. Meza, A. Samra","doi":"10.1109/SECON.1998.673369","DOIUrl":"https://doi.org/10.1109/SECON.1998.673369","url":null,"abstract":"Three-phase bridge rectifiers are widely used in industry to interface DC loads to the electric utility because of their low ripple content output and high power-handling capability. The nonlinear nature of the diode type switching devices causes significant line-current harmonics resulting in increased distortion, malfunction of sensitive electronic equipment, increased losses, and contributes to inefficient use of electric energy. This paper describes a new approach to reduce those line-current harmonics generated by a three-phase diode rectifier type utility interface. The proposed approach consists of a novel interconnection of a delta-zig zag transformer between the AC and DC sides of the diode rectifier topology. This transformer connection in combination with the conduction intervals of each diode generates automatically a circulating third harmonic current between the AC and DC side of the rectifier bridge. Voltage and current analysis and simulation using the Electro-Magnetic Transients Program (EMTP) showed that the generated circulating current may drastically reduce the line current harmonics of the AC side and smooth out the DC output voltage of the rectifier.","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128602239","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}
Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673368
Huai Wei, Issa Batarseh
Basic types of DC-DC converters, when operating in discontinuous conduction mode, have self power factor correction (PFC) property, that is, if these converters are connected to the rectified AC line, they have the capability to give higher power factor by the nature of their topologies. Input current feedback is unnecessary when these converters are employed to improve power factor. In this paper, basic types of DC-DC converter topologies are studied to investigate their self-PFC capabilities. Their input characteristics are compared and their input line current waveforms are predicted.
{"title":"Comparison of basic converter topologies for power factor correction","authors":"Huai Wei, Issa Batarseh","doi":"10.1109/SECON.1998.673368","DOIUrl":"https://doi.org/10.1109/SECON.1998.673368","url":null,"abstract":"Basic types of DC-DC converters, when operating in discontinuous conduction mode, have self power factor correction (PFC) property, that is, if these converters are connected to the rectified AC line, they have the capability to give higher power factor by the nature of their topologies. Input current feedback is unnecessary when these converters are employed to improve power factor. In this paper, basic types of DC-DC converter topologies are studied to investigate their self-PFC capabilities. Their input characteristics are compared and their input line current waveforms are predicted.","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130537242","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}
Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673306
J. Rose, M. Shah
Content-based image retrieval (CBIR) enables a user to extract an image, based on a query, from a database containing a vast amount of pictures. This concept may be applied to many fields of interest including forensic science and image archiving. Current CBIR systems, however, are inaccurate. The purpose of this research project was to improve the accuracy of CBIR. The image's structural properties were examined to distinguish one image from another. By examining the specific gray level of an image, a gradient can be computed at each pixel. Pixels with a magnitude larger than the thresholds are assigned a value of 1. These binary digits are added across the horizontal, vertical, and diagonal directions to compute three projections. These vectors are then compared with the vectors of the image to be matched using the Euclidean distance formula. These numbers are then stored in a bookmark so that the image needs only be examined once. A program has been developed for Matlab on a Sun Sparc Computer with Unix Open Windows that performs this method of projecting gradients. Three databases were amassed for the testing of the proposed system's accuracy: 82 digital camera pictures, 1000 photographic images, and a set of object orientated photos. The program was tested with 100% accuracy with all submitted images to the database, and was able to distinguish between pictures that fooled previous CBIR engines. More importantly, though, was the program's ability to find certain similar scenarios in the database. This CBIR approach has significantly increased the accuracy in obtaining results for image retrieval.
基于内容的图像检索(CBIR)使用户能够根据查询从包含大量图片的数据库中提取图像。这个概念可以应用于许多感兴趣的领域，包括法医学和图像存档。然而，目前的CBIR系统并不准确。本研究项目的目的是提高CBIR的准确性。检查图像的结构属性以区分不同的图像。通过检查图像的特定灰度级，可以在每个像素处计算梯度。大小大于阈值的像素被赋值为1。这些二进制数字在水平、垂直和对角线方向上相加，以计算三个投影。然后将这些矢量与使用欧几里得距离公式进行匹配的图像的矢量进行比较。然后将这些数字存储在书签中，这样图像只需要检查一次。在Sun Sparc计算机和Unix Open Windows上用Matlab编写了一个程序，实现了这种投影梯度的方法。为了测试系统的准确性，收集了三个数据库:82张数码相机照片、1000张摄影图像和一组面向对象的照片。该程序对所有提交到数据库的图像进行了100%的准确率测试，并且能够区分那些欺骗了以前的CBIR引擎的图片。不过，更重要的是，该程序能够在数据库中找到某些类似的场景。该方法显著提高了图像检索结果的准确性。
{"title":"Content-based image retrieval using gradient projections","authors":"J. Rose, M. Shah","doi":"10.1109/SECON.1998.673306","DOIUrl":"https://doi.org/10.1109/SECON.1998.673306","url":null,"abstract":"Content-based image retrieval (CBIR) enables a user to extract an image, based on a query, from a database containing a vast amount of pictures. This concept may be applied to many fields of interest including forensic science and image archiving. Current CBIR systems, however, are inaccurate. The purpose of this research project was to improve the accuracy of CBIR. The image's structural properties were examined to distinguish one image from another. By examining the specific gray level of an image, a gradient can be computed at each pixel. Pixels with a magnitude larger than the thresholds are assigned a value of 1. These binary digits are added across the horizontal, vertical, and diagonal directions to compute three projections. These vectors are then compared with the vectors of the image to be matched using the Euclidean distance formula. These numbers are then stored in a bookmark so that the image needs only be examined once. A program has been developed for Matlab on a Sun Sparc Computer with Unix Open Windows that performs this method of projecting gradients. Three databases were amassed for the testing of the proposed system's accuracy: 82 digital camera pictures, 1000 photographic images, and a set of object orientated photos. The program was tested with 100% accuracy with all submitted images to the database, and was able to distinguish between pictures that fooled previous CBIR engines. More importantly, though, was the program's ability to find certain similar scenarios in the database. This CBIR approach has significantly increased the accuracy in obtaining results for image retrieval.","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130986185","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}
Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673291
J. Ten Eyck, G. Sampath
This paper utilizes the notion of design patterns to provide a description of problem solving. The description provides an object-oriented reference frame for discussing a general problem-solving approach. A design pattern description for the domain of problem solving is presented and the model is developed and explained in terms of an example. The architecture of a reading tool for studying algorithm design is developed from the class model for the problem-solving pattern. This tool is presented as a distributed Web-based application that would allow students to explore design strategies for particular problem sets, and for contributors to expand the capabilities and function of the system in a timely manner.
{"title":"An object model for problem solving and its applications","authors":"J. Ten Eyck, G. Sampath","doi":"10.1109/SECON.1998.673291","DOIUrl":"https://doi.org/10.1109/SECON.1998.673291","url":null,"abstract":"This paper utilizes the notion of design patterns to provide a description of problem solving. The description provides an object-oriented reference frame for discussing a general problem-solving approach. A design pattern description for the domain of problem solving is presented and the model is developed and explained in terms of an example. The architecture of a reading tool for studying algorithm design is developed from the class model for the problem-solving pattern. This tool is presented as a distributed Web-based application that would allow students to explore design strategies for particular problem sets, and for contributors to expand the capabilities and function of the system in a timely manner.","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126023904","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}
Pub Date : 1998-04-24DOI: 10.1109/SECON.1998.673364
J. Zec, W. Linwood Jones
In this paper a simple method for relative antenna calibration is applied to NSCAT (NASA Scatterometer), and the model used is described. Calibration data sets are extracted using high-resolution masks. Results are presented for the Amazon rain forest (traditionally used) and the Siberian plain. Beam correction tables are derived for balancing normalized radar backscatter coefficient measurements from different antennas.
{"title":"Relative calibration of scatterometer antennas using land targets","authors":"J. Zec, W. Linwood Jones","doi":"10.1109/SECON.1998.673364","DOIUrl":"https://doi.org/10.1109/SECON.1998.673364","url":null,"abstract":"In this paper a simple method for relative antenna calibration is applied to NSCAT (NASA Scatterometer), and the model used is described. Calibration data sets are extracted using high-resolution masks. Results are presented for the Amazon rain forest (traditionally used) and the Siberian plain. Beam correction tables are derived for balancing normalized radar backscatter coefficient measurements from different antennas.","PeriodicalId":281991,"journal":{"name":"Proceedings IEEE Southeastcon '98 'Engineering for a New Era'","volume":"117 31","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-04-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120820604","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}
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