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Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)最新文献

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A new method for the design and synthesis of broadband constant phase shift microwave hybrid couplers 一种宽带恒定相移微波杂化耦合器的设计与合成新方法
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711462
H.I. Al-Anwar, I.M. Motawe, H. El Hennawy, S. Mahrous
{"title":"A new method for the design and synthesis of broadband constant phase shift microwave hybrid couplers","authors":"H.I. Al-Anwar, I.M. Motawe, H. El Hennawy, S. Mahrous","doi":"10.1109/NRSC.1998.711462","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711462","url":null,"abstract":"A new proposed method for the design and synthesis of broad band planar microwave directional couplers is presented. This method of synthesis produces couplers, designed to have almost constant phase shift between its two output ports over its useful bandwidth. Examples of hybrid couplers designed using this method with their analysis are presented. The lumped topologies of these couplers can be realized using MMIC technology. The distributed topologies of these couplers have suitable dimensions for realization using microstrip line and stripline technologies.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"204 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122529886","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 new technique for linear antenna array processing for reduced sidelobes using neural networks 一种基于神经网络的线性天线阵副瓣处理新技术
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711446
M. Aboul-Dahab, K.A. Hijjah, S. El-Khamy
{"title":"A new technique for linear antenna array processing for reduced sidelobes using neural networks","authors":"M. Aboul-Dahab, K.A. Hijjah, S. El-Khamy","doi":"10.1109/NRSC.1998.711446","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711446","url":null,"abstract":"In adaptive antenna arrays (AAA), shaping the array factor is a challenging task where different sophisticated adaptation algorithms might be utilized. Applying these algorithms to AAA results in limited performance, due to slow convergence rates and increased computational complexity. The high cost required is another factor that should be taken into consideration. From another point of view, the synthesis of linear arrays to produce highly reduced sidelobes is a problem of similar complexity and limitations. This paper suggests a new synthesis technique for antenna array systems based on a trained neural network (NN). In particular, the output of a linear array is processed by two NNs, The simulation results show that the NN, when trained to minimize the sidelobe levels of the array, results in highly improved patterns with very deep sidelobes. This method substitutes other tedious conventional algorithms that are usually used in adaptive antenna arrays and array synthesis.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123199704","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: 8
Design of scaling and wavelet filters as FIR and IIR filters and their applications 作为FIR和IIR滤波器的尺度滤波器和小波滤波器的设计及其应用
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711480
N. El-Boghdadly, N. Sadek
{"title":"Design of scaling and wavelet filters as FIR and IIR filters and their applications","authors":"N. El-Boghdadly, N. Sadek","doi":"10.1109/NRSC.1998.711480","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711480","url":null,"abstract":"The scaling and wavelet filters play a great role in the wavelet transform. They are used in the generation of the wavelet function by applying the filter implementation method. They are also used in the computation of DWT coefficients algorithms such as the Mallat algorithm implemented by filter banks. These filters coefficients are commonly computed from Daubechies wavelet bases. In this paper, we present another method for the design of scaling and wavelet filters based on the FIR and IIR PR-QMF bank satisfying the regularity condition. Then we apply the designed filters in speech and image data compression by using the Mallet algorithms, and compute between the obtained results and those obtained from using Daubechies wavelet bases.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"140 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132083399","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
Data compression for Arabic text 阿拉伯语文本的数据压缩
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711471
A. Mohamed, A. El-Sawy, S. Ahmad
{"title":"Data compression for Arabic text","authors":"A. Mohamed, A. El-Sawy, S. Ahmad","doi":"10.1109/NRSC.1998.711471","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711471","url":null,"abstract":"The huge amount of data that are being stored/or communicated between different terminals motivates the need for data compression. The compression of data helps in saving the required storage and transmission bandwidth, Several methods for data compression have been proposed in the literature. A new data compression technique is presented here. Its performance is investigated with respect to both English and Arabic texts. In this paper some of the Arabic text statistics are calculated, then the new technique and the other techniques are applied to different types of Arabic and English texts. A comparison is worked out, and an improvement in the compression ratio is observed.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115693410","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
Adaptive-window adaptive order-statistics LMS filter for impulse noise filtering in images 自适应窗自适应阶数LMS滤波器用于图像的脉冲噪声滤波
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711477
M. Hadhoud
{"title":"Adaptive-window adaptive order-statistics LMS filter for impulse noise filtering in images","authors":"M. Hadhoud","doi":"10.1109/NRSC.1998.711477","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711477","url":null,"abstract":"This paper presents an adaptive filter with adaptive window size that is effective in filtering images corrupted with impulse noise and mixed noise (Gaussian, ..., impulse) with limited blurring effects. The filter is based on an adaptive window technique, the image data order statistics, and the LMS adaptive filter. It can be viewed as a three stages filter, the first stage is to identify impulses and passible edges, then use adaptive size calculation to isolate impulses and the third stage is adaptive filtering the remaining data using the adaptive LMS filter. This process of adaptive windowing reduces the filter size and causes reduction in computations which compensates for the excessive amount of comparisons made in sorting the image data. The proposed filter simultaneously removes both positive and negative impulses as compared to other techniques which deal with only one type of impulses at a time. Comparisons with other filtering illustrate its superiority in removing the mixed noise from images.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122914186","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
Design and investigation of a very wide dynamic microwave electronic counter entirely intergrated using traditional MOSFET technology (/spl sim/1E4 Hz to 1E11 Hz) 完全采用传统MOSFET技术集成的超宽动态微波电子计数器(/spl sim/1E4 Hz至1E11 Hz)的设计与研究
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711507
A. El-Hennawy, H. Abd El-Hameed, A. Ramadan, M.A. El-Ftah
{"title":"Design and investigation of a very wide dynamic microwave electronic counter entirely intergrated using traditional MOSFET technology (/spl sim/1E4 Hz to 1E11 Hz)","authors":"A. El-Hennawy, H. Abd El-Hameed, A. Ramadan, M.A. El-Ftah","doi":"10.1109/NRSC.1998.711507","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711507","url":null,"abstract":"The paper presents a new MOSFET IC frequency to frequency converter (FFC) which can measure frequency, period, frequency ratio, time interval, event counting, rise and fall time, pulse width, duty cycle and statistical information (repeating mode, software, storage memory). The proposed FFC is based on a new technique of operation comprising transformation from high (upper microwave frequencies) to appropriate easily measurable frequencies (/spl sim/1 Hz to 1 E6 Hz) with excellent resolution (/spl sim/0.1 ppm). It uses a very low level current to frequency converter (CFC) operating in its exponential mode. The FFC is entirely integrated using the standard 2 /spl mu/m MOSFET technology.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129720493","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 novel MOSFET FM-detector circuit entirely integrated on a single chip 一种完全集成在单芯片上的新型MOSFET fm检测器电路
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711511
A. El Hennawy, A. Zekry, S. Bayomi, S. Saafan
{"title":"A novel MOSFET FM-detector circuit entirely integrated on a single chip","authors":"A. El Hennawy, A. Zekry, S. Bayomi, S. Saafan","doi":"10.1109/NRSC.1998.711511","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711511","url":null,"abstract":"Already known FM demodulator circuits are limited in use because of some associated drawbacks. Inherent nonlinearity and response to undesired amplitude variations are examples of these limitations. Also, realization of such circuits on a single chip is impossible because they need to employ transformers, inductors and/or large capacitors. A novel FM detector circuit, which is entirely integrated using MOSFET technology, on a single chip is developed in this paper. It is precise, linear over a wide frequency range (>200 kHz), reliable and providing stable characteristics. It is also simple to design, easy to use and inexpensive to realize. Moreover, it is compatible with the recent scaling down trends.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"136 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116717827","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
Effect of number of labels on the accuracy of function approximation 标签数对函数逼近精度的影响
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711500
I. Khalifa, A. El-Assal, M. Saleh
{"title":"Effect of number of labels on the accuracy of function approximation","authors":"I. Khalifa, A. El-Assal, M. Saleh","doi":"10.1109/NRSC.1998.711500","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711500","url":null,"abstract":"The approximation problem of any nonlinear map using a fuzzy basis function is discussed. This fuzzy basis function (FBF) has the capability of combining both numerical data and linguistic information. The main design objective is to construct an output error for which the number of labels can be varied. In this work, an optimal fuzzy approach is proposed which is capable of matching all the training input-output pairs. The advantage of this approach is that, it produces a simple well-performed method to minimize an objective function in the output error. Simulation results demonstrate the effectiveness of determining the proper number of labels that help drastically in reducing errors between the real function and its representation.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"23 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123757567","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
Video signal compression using prenonlinear filtering and a novel error correction technique 视频信号压缩采用预非线性滤波和一种新的纠错技术
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711460
H. Elkamchouchi, H. Hafez
{"title":"Video signal compression using prenonlinear filtering and a novel error correction technique","authors":"H. Elkamchouchi, H. Hafez","doi":"10.1109/NRSC.1998.711460","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711460","url":null,"abstract":"In this paper, a nonlinear filter with a suitable transfer function is used at the front of the video compression transmitter. This filter reduces the range of relative amplitudes between the input sample amplitudes which results in increasing the discrete cosine transform (DCT) and discrete wavelet transform (DWT) abilities to concentrate the signal information in the lower frequency band and hence increasing the image compression ratio. In the receiver, an inverse filter is used after the inverse discrete cosine transform (IDCT) or inverse discrete wavelet transform (IDWT) to regain the signal information. The error due to neglecting high frequency bands was found to be approximately equal for each of the samples. Because the error is either positive or negative, using one bit of the quantization word will be very helpful to add the transmitted average error correctly at the receiving end with a very small negative effect on the quantization error due to the small difference between the sample amplitudes.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"89 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127138698","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
Absolute parametric instability in a nonuniform cylindrical plasma waveguide 非均匀圆柱形等离子体波导的绝对参数不稳定性
Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109) Pub Date : 1998-02-24 DOI: 10.1109/NRSC.1998.711520
V. Demchenko, K. El-Shorbagy, S. Khalil, N. G. Zaki
{"title":"Absolute parametric instability in a nonuniform cylindrical plasma waveguide","authors":"V. Demchenko, K. El-Shorbagy, S. Khalil, N. G. Zaki","doi":"10.1109/NRSC.1998.711520","DOIUrl":"https://doi.org/10.1109/NRSC.1998.711520","url":null,"abstract":"The paper reports an analysis of the effect of spatial plasma nonuniformity on the parametric instability of electrostatic waves in magnetized cylindrical waveguides subjected to an intense HF electric field. It is shown that allowance for the spatial nonuniformity leads: (1) to localization of an unstable wave in a finite region of the plasma volume, (2) to an increase in the threshold value of the pump wave amplitude above which parametric amplification occurs and (3) to a decrease in the value of the growth rate of the unstable waves.","PeriodicalId":128355,"journal":{"name":"Proceedings of the Fifteenth National Radio Science Conference. NRSC '98 (Cat. No.98EX109)","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1998-02-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131275726","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
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