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Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)最新文献

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Analysis and characteristics of the continuous spectrum of modes of the axially slotted coaxial line 轴向开槽同轴线模态连续谱的分析与特性
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838843
K. Hussein, E. El-Diwany
{"title":"Analysis and characteristics of the continuous spectrum of modes of the axially slotted coaxial line","authors":"K. Hussein, E. El-Diwany","doi":"10.1109/NRSC.2000.838843","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838843","url":null,"abstract":"The discrete modes of the axially slotted coaxial line were investigated in many articles. However, the continuous spectrum of modes has not been investigated before. The complete spectrum (discrete and continuous) is required to solve radiation and discontinuity problems of such cylindrical slot/strip lines using modal methods such as the mode matching technique. In this work, the problem of the continuous spectrum of the relevant line is solved using the Riemann-Hilbert problem technique. The analysis reveals the existence of two sets of modes with perpendicular polarizations: one of Ez-even-Hz-odd symmetry about the plane of symmetry of the line, and the other of Hz-even-Ez-odd symmetry. The continuous modes propagating along the line are standing waves in the radial direction. For each propagation constant of the continuous spectrum there are different possible dependencies on the angular dimension, thereby constituting what may be called \"transverse patterns\" or \"angular modes\". The characteristics and field configurations of a variety of such modes are investigated in this work. Interesting results of continuous transformations of one angular mode to another when varying the longitudinal propagation constant, the operating frequency and the slot width, are shown in this paper.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"15 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126922023","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
Impact of the current global revolution in communication systems and networks on the social and economic lives in the Middle East 当前全球通信系统和网络革命对中东社会和经济生活的影响
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838835
A. Abed
{"title":"Impact of the current global revolution in communication systems and networks on the social and economic lives in the Middle East","authors":"A. Abed","doi":"10.1109/NRSC.2000.838835","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838835","url":null,"abstract":"We have demonstrated, in this paper, the potential of the knowledge-based society, opportunities, challenges and risks. It was noted, that there are many open issues, which need to be well evaluated in order to select the appropriate option for our region. Special emphasis, should be given to improve the infrastructure of the Internet backbone to be able to cope with the growing demand for high capacity transmission. Open issues on content, intellectual property rights (IPR) and privacy should seriously be debated and appropriate legislation should be issued. It is to be noted that the Arab world, could not afford to miss the present opportunities and that all effort should be directed to take advantage on the regional and international level of the current IT achievements.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122324871","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
Linear dipole with parallel-piped metallic reflector 具有平行管道金属反射器的线性偶极子
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838912
H. Elkamchouchi, M. N. Abd El-Salam
{"title":"Linear dipole with parallel-piped metallic reflector","authors":"H. Elkamchouchi, M. N. Abd El-Salam","doi":"10.1109/NRSC.2000.838912","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838912","url":null,"abstract":"A new antenna is proposed in this paper by constructing a simple antenna system, which consists of a /spl lambda//2 dipole antenna parallel to a parallel-piped metallic reflector. This combination led to a great modification in the antenna gain in the horizontal plane, which represents the main radiation plane. The method of moments is used in the analysis via a computer-aided code (NEC). Both the electric field integral equation (EFIE) and the magnetic field integral equation (MFIE) were used to analyze the wire and surfaces respectively.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128689709","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
Scattering of an electromagnetic beam by a radially inhomogeneous sphere 辐射状非均匀球体对电磁波束的散射
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838841
E. Khaled, M. Salem
{"title":"Scattering of an electromagnetic beam by a radially inhomogeneous sphere","authors":"E. Khaled, M. Salem","doi":"10.1109/NRSC.2000.838841","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838841","url":null,"abstract":"A method to calculate the scattering intensities of a multilayered sphere or a radially inhomogeneous sphere is presented. The sphere is illuminated with an electromagnetic wave of an arbitrary spatial distribution. The radially inhomogeneous sphere is modeled by a multilayered sphere. The method uses the technique presented by Wu and Wang (1991) and by Johnson (see Appl. Opt., vol.35, p.3285-96, 1996) to calculate the scattering coefficients of a multilayered sphere and a method that represent an arbitrary incident beam in terms of vector spherical harmonics (VSH). The presented method is used to calculate the backscattered and angular scattering intensities of a multilayered and a radially inhomogeneous spheres illuminated with a Gaussian beam. The method is capable of calculating the scattered field of any scatterer as long as its scattering coefficients are known. Also the method can be used for a tightly focused incident beam. The beam can be focused to an arbitrary position with respect to the sphere.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130631843","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
Laser altimetry and its application in geographic scanning 激光测高及其在地理扫描中的应用
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838966
A. H. Morshed
{"title":"Laser altimetry and its application in geographic scanning","authors":"A. H. Morshed","doi":"10.1109/NRSC.2000.838966","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838966","url":null,"abstract":"Laser altimetry is a technique whereby reflections of a laser beam are used to measure the altitude of an aircraft above the ground based on a round trip delay measurement. With current improvements in short laser pulse generation and high resolution time and amplitude measurements, the same technique is now used to measure topographical features of the ground surface. In addition to surface elevations obtained from high resolution delay measurements, information on the nature of coverage of a target surface can be obtained from high resolution intensity measurements of the returned echo signal. In this technique, global positioning and navigation guidance are needed to provide reference on the position and pointing attitude of the measuring equipment. Both aspects of the altimeter system, namely, echo signal measurements and position referencing, determine the accuracy and resolution of the technique. This paper reviews the principles and basic aspects of a pulsed laser altimeter, and discusses the utilization of data provided by laser altimetry in geographic scanning for urban and environmental studies.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"50 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125640903","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
A convenient calibration procedure of four-port reflectometers: application on six-port reflectometer and heterodyne network analyzer 一种方便的四端口反射计校准程序:在六端口反射计和外差网络分析仪上的应用
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838844
S. Abou chahine, B. Huyart, L. Jallet
{"title":"A convenient calibration procedure of four-port reflectometers: application on six-port reflectometer and heterodyne network analyzer","authors":"S. Abou chahine, B. Huyart, L. Jallet","doi":"10.1109/NRSC.2000.838844","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838844","url":null,"abstract":"This paper presents a millimeter-wave six-port reflectometer in the W-frequency band (75-110 GHz). A convenient calibration technique requiring two standards is described. The measurement performance of this method is compared with the results of a dual six-port network analyzer using the LRL calibration procedure. Moreover, characterization of some components by the heterodyne network analyzer in the reflection mode using this technique and other calibration methods are presented.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133519339","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
A modified fuzzy Sobel edge detector 一种改进的模糊索贝尔边缘检测器
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838961
S. El-Khamy, M. Lotfy, N. El-Yamany
{"title":"A modified fuzzy Sobel edge detector","authors":"S. El-Khamy, M. Lotfy, N. El-Yamany","doi":"10.1109/NRSC.2000.838961","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838961","url":null,"abstract":"A modified fuzzy Sobel method for edge detection and enhancement is proposed. This method is a modification of the fuzzy Sobel method proposed by Kuo, Lee and Liu see (IEEE Conference on Fuzzy Systems, p.1069-74, 1997). The proposed method overcomes the drawbacks of the conventional gradient methods for edge detection such as Prewitt and Sobel methods. It automatically obtains four threshold values, and apply fuzzy reasoning for edge enhancement. The edges extracted by this method are very clear and provides better representation for image edges and object contours.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"482 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116896663","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: 69
Atomic force microscope image enhancement using human visual system model properties and adaptive filters 原子力显微镜图像增强利用人类视觉系统模型属性和自适应滤波器
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838978
M. Hadhoud, R. Atta
{"title":"Atomic force microscope image enhancement using human visual system model properties and adaptive filters","authors":"M. Hadhoud, R. Atta","doi":"10.1109/NRSC.2000.838978","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838978","url":null,"abstract":"Atomic force microscope (AFM) images are usually of poor quality and need to be interpreted visually. The human visual system (HVS) is generally modeled as an adaptive, multichannel and highly non-linear system. This paper proposes an adaptive image enhancement systems for improving the quality of the AFM images. The proposed method is based on a combination of an adaptive low pass filter and a single channel adaptive high pass filter using homomorphic processing. The proposed system is nonlinear through the use of the homomorphic transformation and the adaptation of contrast enhancement parameters to the change in the input local characteristics and contrast. Comparison with other fixed and adaptive contrast enhancement filters is made to show the improvement obtained using the proposed method.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117196839","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
A new constrained fast null steering algorithm 一种新的约束快速零转向算法
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838950
H. Elkamchouchi, M. A. Elsalam
{"title":"A new constrained fast null steering algorithm","authors":"H. Elkamchouchi, M. A. Elsalam","doi":"10.1109/NRSC.2000.838950","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838950","url":null,"abstract":"A new algorithm is presented based on the constrained fast null steering algorithm. The structure of this new algorithm is simplified compared with that of the tree structure of the constrained fast null steering. A multiplier which is inserted in the structure, multiplies the output of any summing points with the main output. The function of the multiplier is to transfer a zero when occurring at any summing points to the main output. Numerical evaluation proved the validity and simplicity of this algorithm using 3, 4, and 5 elements array.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117267870","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: 4
Optical fiber wavelength division multiplexer based on two-mode interference 基于双模干涉的光纤波分复用器
Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396) Pub Date : 2000-02-22 DOI: 10.1109/NRSC.2000.838971
A. Abou El-fadl, S. Eladl, M. Rageh
{"title":"Optical fiber wavelength division multiplexer based on two-mode interference","authors":"A. Abou El-fadl, S. Eladl, M. Rageh","doi":"10.1109/NRSC.2000.838971","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838971","url":null,"abstract":"An optical fiber wavelength division multiplexer based on two-mode interference has been analyzed. A theoretical model based on solution of the wave equation for a two-mode optical waveguide by computing their propagation characteristics is used. In addition, the coupled power between these two modes has been investigated. The dependence of the coupled power on the wavelength, the core radius and the refractive index is studied. The variations of the beat length against the core radius and the operating wavelength, the variations of the crosstalk against the length of the device and the operating wavelength have been also investigated. The results show that the variations of the wavelength change the coupled power between the two modes from 0% to 100%, and show that this type of model can be exploited as an optical wavelength division multiplexer (WDM) for single-mode optical fiber systems.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"53 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128174651","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
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