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Proceedings of the Nineteenth National Radio Science Conference最新文献

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A new technique for enhanced regularized image restoration 一种增强正则化图像恢复新技术
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022638
M. Hadhoud, M. Dessouky, F. A. Abd El-Samie, S. El-Khamy
{"title":"A new technique for enhanced regularized image restoration","authors":"M. Hadhoud, M. Dessouky, F. A. Abd El-Samie, S. El-Khamy","doi":"10.1109/NRSC.2002.1022638","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022638","url":null,"abstract":"The pivoting problem encountered in regularized image restoration is how to evaluate the regularization parameter. Existing methods for evaluating this regularization parameter are categorized to two main groups; methods that require knowledge of the noise variance in the degraded image and methods that do not. This paper suggests a new approach for choosing the regularization parameter. It depends on maximizing the power in the restored image by the coincidence of the passband of the regularization filter with the frequency band in which most of the image power exists. The suggested method has an iterative nature and requires no a priori knowledge of the noise variance, which may be inexact. Results show that the estimated value of the regularization parameter coincides. with the minimum of the mean squared error and results in enhanced image restoration.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124313216","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
Improved method for blocking-artifact reduction in block coded images in wavelet-transform domain 改进的小波变换域分块编码图像的块伪影减少方法
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022636
M. Hadhoud, M. Foaad, H.A. Abd Allah
{"title":"Improved method for blocking-artifact reduction in block coded images in wavelet-transform domain","authors":"M. Hadhoud, M. Foaad, H.A. Abd Allah","doi":"10.1109/NRSC.2002.1022636","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022636","url":null,"abstract":"The paper describes an approach for improving blocking-artifact reduction techniques. We purpose some simple processing methods in the wavelet transform domain that can reduce the blocking effects in block-coded images. The properties of block-coding make the errors appear in two categories: blocky noise, which causes blocking effects, and granular (non-blocky) noise. Once a degraded image is decomposed into subbands by wavelet filters, most energy of the blocky noise exists on the predetermined block boundaries of their corresponding subbands. We can reduce the blocky noise by using an averaging filter, a median filter, or the linear minimum mean square error in each subband. After the blocky noise is reduced, the granular noise can be further decreased. The approach was tested by applying it to images (Lena, cameraman). Results presented provide an improvement in the processed image.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123819259","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
Mapping of land mines using air borne radars 利用机载雷达测绘地雷
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022670
N. Ismail, H.N. Khairallah, M. Metwally
{"title":"Mapping of land mines using air borne radars","authors":"N. Ismail, H.N. Khairallah, M. Metwally","doi":"10.1109/NRSC.2002.1022670","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022670","url":null,"abstract":"The detection of land mines using an air borne radar is investigated. The relation between the height of the radar and the separation distance between regular linear distributed mines is obtained. Bistatic and monostatic radars are employed with different operating frequencies to detect the number of mines and their locations. An E-plane or H-plane horn antenna can be used during the simulation.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130425704","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
Quality improvement of low-bit-rate noisy speech using the subspace method 利用子空间方法提高低比特率噪声语音的质量
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022627
M. El-Mahallawy, W. Fakhr, H. Hamdy
{"title":"Quality improvement of low-bit-rate noisy speech using the subspace method","authors":"M. El-Mahallawy, W. Fakhr, H. Hamdy","doi":"10.1109/NRSC.2002.1022627","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022627","url":null,"abstract":"Additive noise presents a particularly difficult problem for linear predictive-based speech coding (LPC) systems operating at sampling rates up to 4.8 kb/s. The performance. of cascade signal-subspace-based speech enhancement algorithm/code excited linear predictive (CELP) coding system is studied and compared with the conventional cascade spectral-subtraction-based speech enhancement algorithm/CELP system. Both systems have been tested under the same conditions, i.e. the same type of noise (white noise) and the same signal-to-noise-ratios. An LPC-based objective test is used for the evaluation of both systems. Based on this test, it is shown that the signal-subspace-based speech enhancement algorithm outperforms the spectral-subtraction-based speech enhancement algorithm such that it could be recommended as a preprocessor for any LPC speech coding system.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133814399","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 simple analysis of a multimode three optical slab waveguides directional coupler 多模三光板波导定向耦合器的简单分析
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022665
A. Zaghloul
{"title":"A simple analysis of a multimode three optical slab waveguides directional coupler","authors":"A. Zaghloul","doi":"10.1109/NRSC.2002.1022665","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022665","url":null,"abstract":"A new algorithm is presented to analyze three optical slab waveguide directional couplers to obtain the power transferred and field distribution through slabs. Using the effective index method, the coupler is treated as three couplers, each consisting of two slabs and the effect of the remainder waveguide is taken into account. The coupling coefficient between two slabs is derived by approximate coupled mode theory. The power transferred is evaluated by using a coupled wave differential equation system and Laplace transform. The transverse field distribution is calculated by using the power contained through each waveguide. Two coupled waveguides can be isolated by using an intermediate waveguide, which applies the isolation condition with higher values of the propagation constant than that of the original waveguides. A simple calculation of the intermediate waveguide is derived. The effect of coupler parameters on power transferred is applied. The obtained results are compared with other published data and these results can be used as design guide curves.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"29 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125993638","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
An automatic system for the analysis and classification of esophageal motility records 用于分析和分类食管运动记录的自动系统
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022648
F. Abou-Chadi, A. Sif El-Din, N. Gad-el-Hak
{"title":"An automatic system for the analysis and classification of esophageal motility records","authors":"F. Abou-Chadi, A. Sif El-Din, N. Gad-el-Hak","doi":"10.1109/NRSC.2002.1022648","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022648","url":null,"abstract":"Signal processing techniques as well as feature extraction and pattern classification criteria were utilized to develop a system that automatically classifies esophageal motility records into normal and different abnormal cases. The system consists of four parts: processing the recorded signal to remove noise interference, automatic isolation of the different parts of the esophagus, extracting a set of features that quantifies the records, and a classifier to discriminate the different cases. Classification was accomplished using a two-level classifier. A multilayer feedforward neural network trained using the backpropagation algorithm was utilized. Classification of the tubular part and the lower esophageal sphincter was performed separately. The results have shown that 97.4% and 100% correct classification were obtained for the tubular body and the lower sphincter, respectively. It is concluded that the adopted techniques are highly relevant to esophageal data and that the approach followed is feasible and can become a powerful tool for automatic esophageal diagnosis.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121727815","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
Broadband triangle slotted patch antenna for wireless local area network 用于无线局域网的宽带三角形开槽贴片天线
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022620
H. Elkamchouchi, H. Hafez
{"title":"Broadband triangle slotted patch antenna for wireless local area network","authors":"H. Elkamchouchi, H. Hafez","doi":"10.1109/NRSC.2002.1022620","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022620","url":null,"abstract":"A single-layer single-element probe-fed slotted patch antenna is proposed to feature a broad impedance bandwidth and low cross-polarization levels. Detailed investigations are presented through the results obtained using the method of moments technique. The broad band triangle slotted patch antenna (BTSPA) proved many attractive features so that it is recommended to be used in wireless local area networks. The design of the antenna considers simplicity, compact size (77% of the other equivalent slotted plate antenna such as broad band rectangle slotted plate antenna), and low cost. It has highly directed radiation pattern plane with peak in the bore sight achieving great gain. The impedance bandwidth reaches up to the order of 20%. Both of the stable radiation patterns and the high gain levels (more than 9.1 dB) are observed across the pass-band.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"371 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124645319","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
FDTD analysis of wide-band circular and annular-ring patch antennas 宽带圆形和环形贴片天线的时域有限差分分析
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022618
A. Mahmoud, M.M. Abd Elrazzak, A. Mitkees, H. Elmikati
{"title":"FDTD analysis of wide-band circular and annular-ring patch antennas","authors":"A. Mahmoud, M.M. Abd Elrazzak, A. Mitkees, H. Elmikati","doi":"10.1109/NRSC.2002.1022618","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022618","url":null,"abstract":"A finite-difference time-domain (FDTD) analysis of gap-coupled circular patch antennas (GCCPA) on isotropic substrates is presented. The return loss, the input impedance and the radiation pattern are determined. Similar analysis is performed for the stacked-gap coupled (SGC) annular-ring microstrip antennas. About 40% -10 dB bandwidth is achieved which is eight times more than that of the single annular-ring antenna. The results obtained by the FDTD method are found to be in good agreement with the published data.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"2016 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127362874","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
Texture segmentation using Kohonen self organizing feature map 基于Kohonen自组织特征映射的纹理分割
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022637
Mahmoud Elghazali, Hossam Eldin M. Abdelbaki, Abdelslam Fathi
{"title":"Texture segmentation using Kohonen self organizing feature map","authors":"Mahmoud Elghazali, Hossam Eldin M. Abdelbaki, Abdelslam Fathi","doi":"10.1109/NRSC.2002.1022637","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022637","url":null,"abstract":"This paper presents a range of techniques for texture segmentation using Kohonen self organizing feature maps (KSOFM). Various features, based on fractals and energy measures, are extracted from the texture images and then applied to the neural network. First, local features are extracted from the whole image using overlapping windows, then the feature vectors of each window are placed into the feature space. KSOFM is used as a clustering technique to assign a label to the groups that have similar features. A smoothing algorithm is performed followed by edge detection to give an edge map of the segmented image. An integrated software has been developed to illustrate the complete process of texture segmentation.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"67 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126259591","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 computer simulation of the switching effect in superconducting SAW delay lines 超导SAW延迟线开关效应的计算机模拟
Proceedings of the Nineteenth National Radio Science Conference Pub Date : 2002-11-07 DOI: 10.1109/NRSC.2002.1022653
T. E. Taha, M. Elkordy, A. Gomaa
{"title":"A computer simulation of the switching effect in superconducting SAW delay lines","authors":"T. E. Taha, M. Elkordy, A. Gomaa","doi":"10.1109/NRSC.2002.1022653","DOIUrl":"https://doi.org/10.1109/NRSC.2002.1022653","url":null,"abstract":"A novel concept for the interaction between a surface acoustic wave (SAW) and a superconducting thin film deposited on the surface of a piezoelectric substrate is presented. The thin film superconductor complex conductivity is described with the aid of the two-fluid model. The effects of the superconductor complex conductivity on the propagation characteristics of the SAW are given. The obtained results show that the attenuation of the SAW is proportional to the resistivity of the thin film even through the superconductor transitions. It is found that there is an abrupt jump in the SAW attenuation and velocity at the critical conductivity which can be used as an on/off switching mechanism in SAW delay lines. Our simulation results give good agreement with published experimental data. The SAW attenuation and velocity measurements can be used as a useful technique in superconductor characterization.","PeriodicalId":231600,"journal":{"name":"Proceedings of the Nineteenth National Radio Science Conference","volume":"66 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2002-11-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123197433","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
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