Pub Date : 2000-02-22DOI: 10.1109/NRSC.2000.838839
A. El-Hennawy, N. M. El-Minyawi, T. A. Al-Saeed
An accurate full-wave mode matching approach is used to analyze the dispersion characteristics of shielded microstrip. In contrast to the usual perturbation method it includes metallic loss by a self-consistent description without skin effect approximation. The analysis holds for arbitrary high losses and also for metallization dimensions smaller than the skin depth. The metallic strip is considered to be of finite conductivity with finite metallization thickness. The substrate used is GaAs.
{"title":"Characteristics of shielded microstrip with finite conductivity and finite strip thickness","authors":"A. El-Hennawy, N. M. El-Minyawi, T. A. Al-Saeed","doi":"10.1109/NRSC.2000.838839","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838839","url":null,"abstract":"An accurate full-wave mode matching approach is used to analyze the dispersion characteristics of shielded microstrip. In contrast to the usual perturbation method it includes metallic loss by a self-consistent description without skin effect approximation. The analysis holds for arbitrary high losses and also for metallization dimensions smaller than the skin depth. The metallic strip is considered to be of finite conductivity with finite metallization thickness. The substrate used is GaAs.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128437360","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 : 2000-02-22DOI: 10.1109/NRSC.2000.838943
M. Elbably
A new approach, represented by an algorithm is introduced for asynchronous sequential logic circuits. It provides an efficient procedure to avoiding the race conditions. The algorithm procedures have been developed to identify the race conditions and to prevent the system from malfunctioning. Moreover, it provides convenient and efficient procedures without any complexity in hardware or reduction in the system's speed.
{"title":"State machine transition to avoid the race conditions in asynchronous sequential logic circuits","authors":"M. Elbably","doi":"10.1109/NRSC.2000.838943","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838943","url":null,"abstract":"A new approach, represented by an algorithm is introduced for asynchronous sequential logic circuits. It provides an efficient procedure to avoiding the race conditions. The algorithm procedures have been developed to identify the race conditions and to prevent the system from malfunctioning. Moreover, it provides convenient and efficient procedures without any complexity in hardware or reduction in the system's speed.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130634956","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 : 2000-02-22DOI: 10.1109/NRSC.2000.838931
N. El-Fishawy
The future broadband wireless networks require an efficient access protocol to fulfill varying quality of service (QoS) requirements for multimedia applications. In this paper, the packet reservation multiple access (PRMA) protocol is adopted for the transmission of voice and data over the wireless channel, then the protocol is modified in order to support video traffic. The proposed protocol aims at satisfying the stringent requirements of video traffic as well as achieving better channel utilization. Two models of different traffic weights are considered to evaluate the performance of the proposed protocol. Simulation results show that, the protocol achieves high efficiency and guaranteed QoS.
{"title":"Evaluation of the packet reservation multiple access protocol for supporting multimedia services over wireless networks","authors":"N. El-Fishawy","doi":"10.1109/NRSC.2000.838931","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838931","url":null,"abstract":"The future broadband wireless networks require an efficient access protocol to fulfill varying quality of service (QoS) requirements for multimedia applications. In this paper, the packet reservation multiple access (PRMA) protocol is adopted for the transmission of voice and data over the wireless channel, then the protocol is modified in order to support video traffic. The proposed protocol aims at satisfying the stringent requirements of video traffic as well as achieving better channel utilization. Two models of different traffic weights are considered to evaluate the performance of the proposed protocol. Simulation results show that, the protocol achieves high efficiency and guaranteed QoS.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117108303","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 : 2000-02-22DOI: 10.1109/NRSC.2000.838960
S. El-Khamy, O. Abdel-Alim, M. Saii
Recognition method of human face using statistical analysis feature extraction and a neural network algorithm is proposed. In the preprocessing step we detect the edges of the face image by using the Sobel algorithm. Then we propose a new method to transform the two-dimension black and white image to a one-dimension vector. Finally, based on the statistical analysis, we extract seven features. In the recognition step we use the fast backpropagation (FBP) algorithm. Computer simulation results with 100 test images of 10 persons (the images of each person in a various pauses, facial expression, and facial details) show that the proposed method yields a high recognition rate.
{"title":"Neural network face recognition using statistical feature extraction","authors":"S. El-Khamy, O. Abdel-Alim, M. Saii","doi":"10.1109/NRSC.2000.838960","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838960","url":null,"abstract":"Recognition method of human face using statistical analysis feature extraction and a neural network algorithm is proposed. In the preprocessing step we detect the edges of the face image by using the Sobel algorithm. Then we propose a new method to transform the two-dimension black and white image to a one-dimension vector. Finally, based on the statistical analysis, we extract seven features. In the recognition step we use the fast backpropagation (FBP) algorithm. Computer simulation results with 100 test images of 10 persons (the images of each person in a various pauses, facial expression, and facial details) show that the proposed method yields a high recognition rate.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124631567","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 : 2000-02-22DOI: 10.1109/NRSC.2000.838848
A. M. Atiya, E. El-Diwany, A.M. Shaarwai
The problem of transmission and reflection of TE electromagnetic X-waves normally incident on a lossy dispersive half-space is investigated. Such X-waves are represented as a superposition of pulsed plane waves in all azimuth directions and tilted by a constant angle with respect to the X-wave propagation direction. The problem of transmission and reflection of pulsed TE electromagnetic plane waves in the presence of a lossy dispersive half-space is formulated in the frequency domain and is converted to the time domain via Fourier transformation. The transmission coefficient, the reflection coefficient, and the longitudinal propagation function inside the lossy dispersive medium are frequency dependent. A new efficient and accurate method is used to evaluate the inverse Fourier transform where the asymptotic forms of the frequency dependent parameters are obtained, and the corresponding fields are evaluated analytically. The remaining part of the integrand is a fast decaying function of frequency that can be approximated by a series of exponential functions via Prony's method. The Fourier transform of such exponential terms is evaluated analytically in closed form.
{"title":"Transmission and reflection of TE electromagnetic X-wave normally incident on a lossy dispersive half-space","authors":"A. M. Atiya, E. El-Diwany, A.M. Shaarwai","doi":"10.1109/NRSC.2000.838848","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838848","url":null,"abstract":"The problem of transmission and reflection of TE electromagnetic X-waves normally incident on a lossy dispersive half-space is investigated. Such X-waves are represented as a superposition of pulsed plane waves in all azimuth directions and tilted by a constant angle with respect to the X-wave propagation direction. The problem of transmission and reflection of pulsed TE electromagnetic plane waves in the presence of a lossy dispersive half-space is formulated in the frequency domain and is converted to the time domain via Fourier transformation. The transmission coefficient, the reflection coefficient, and the longitudinal propagation function inside the lossy dispersive medium are frequency dependent. A new efficient and accurate method is used to evaluate the inverse Fourier transform where the asymptotic forms of the frequency dependent parameters are obtained, and the corresponding fields are evaluated analytically. The remaining part of the integrand is a fast decaying function of frequency that can be approximated by a series of exponential functions via Prony's method. The Fourier transform of such exponential terms is evaluated analytically in closed form.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124097159","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 : 2000-02-22DOI: 10.1109/NRSC.2000.838952
M. El-Mahlawy, W. Waller
We present an efficient algorithm to design convolved LFSR/SRs (linear feedback shift register/shift registers). Convolved LFSR/SR is considered to be the most efficient pseudoexhaustive test pattern generator as far as the lengths of test set and hardware overhead are concerned. We present an efficient search algorithm to assign the residues to the inputs of the circuit under test (CUT) so as to increase the number of potential solutions and thus reduce the hardware overhead. The experimental results indicate the efficiency of the approach.
{"title":"An efficient algorithm to design convolved LFSR/SR","authors":"M. El-Mahlawy, W. Waller","doi":"10.1109/NRSC.2000.838952","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838952","url":null,"abstract":"We present an efficient algorithm to design convolved LFSR/SRs (linear feedback shift register/shift registers). Convolved LFSR/SR is considered to be the most efficient pseudoexhaustive test pattern generator as far as the lengths of test set and hardware overhead are concerned. We present an efficient search algorithm to assign the residues to the inputs of the circuit under test (CUT) so as to increase the number of potential solutions and thus reduce the hardware overhead. The experimental results indicate the efficiency of the approach.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116882410","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 : 2000-02-22DOI: 10.1109/NRSC.2000.838954
E. Mohammed, E. Emarah, K. El-Shennawy
The use of public key cryptosystems has received considerable attention. They are beneficial in encryption as well as signing which plays an essential role in electronic banking and financial transactions. This paper presents a new generalized blind signature scheme based on ElGamal (1985) signatures. This new scheme has a valuable property that assures that if a message is signed multiple times, the corresponding signatures will be different. This adds to the anonymity of the blind signatures. The new scheme uses number theory operations and modular arithmetic techniques to achieve the desired goal. The current research introduces a generalized signature scheme that could be used to generate blind signatures as well as ordinary ElGamal signatures. The new scheme is found to be comparable to the RSA blinding. Moreover, the new scheme has the advantage of having less computational complexity and is faster than RSA in the blinding procedure.
{"title":"A blind signature scheme based on ElGamal signature","authors":"E. Mohammed, E. Emarah, K. El-Shennawy","doi":"10.1109/NRSC.2000.838954","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838954","url":null,"abstract":"The use of public key cryptosystems has received considerable attention. They are beneficial in encryption as well as signing which plays an essential role in electronic banking and financial transactions. This paper presents a new generalized blind signature scheme based on ElGamal (1985) signatures. This new scheme has a valuable property that assures that if a message is signed multiple times, the corresponding signatures will be different. This adds to the anonymity of the blind signatures. The new scheme uses number theory operations and modular arithmetic techniques to achieve the desired goal. The current research introduces a generalized signature scheme that could be used to generate blind signatures as well as ordinary ElGamal signatures. The new scheme is found to be comparable to the RSA blinding. Moreover, the new scheme has the advantage of having less computational complexity and is faster than RSA in the blinding procedure.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132582175","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 : 2000-02-22DOI: 10.1109/NRSC.2000.838972
O. Alim, H. Khater
This paper provides an analysis of the echo structures returning from underwater targets, then it describes the effect of turbulence on underwater target recognition. The sonar signal recognition system deals with the echoes received from complex geometrical shapes of underwater targets. Practical measurements were carried out in the Naval Research Center (NRC) in Alexandria that is supported by a standard water tank. When the vibration system in the water tank started, the effect of turbulence on the received echoes that returned from the targets was included.
{"title":"Effect of turbulence on underwater targets recognition","authors":"O. Alim, H. Khater","doi":"10.1109/NRSC.2000.838972","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838972","url":null,"abstract":"This paper provides an analysis of the echo structures returning from underwater targets, then it describes the effect of turbulence on underwater target recognition. The sonar signal recognition system deals with the echoes received from complex geometrical shapes of underwater targets. Practical measurements were carried out in the Naval Research Center (NRC) in Alexandria that is supported by a standard water tank. When the vibration system in the water tank started, the effect of turbulence on the received echoes that returned from the targets was included.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132310459","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 : 2000-02-22DOI: 10.1109/NRSC.2000.838959
S. El-Khamy, E. Gelenbe, H. Abdelbaki
A neural network based direct sequence spread spectrum code synchronization system is proposed. The's system is based on training a recurrent random neural network (RNN) model on all the possible phases of the used spreading code. The trained network can then be used at the receiver for the initial coarse alignment of the local code phase and the received code. One advantage of this technique over the conventional synchronization techniques is that the phase of the received PN code can be decided without searching the potential code phases. Also the RNN, after being trained, can have a simple hardware realization that makes it candidate for implementation as a dedicated chip. This makes the neural network based technique faster and more robust than the conventional techniques. Computer simulations, carried out on maximal length sequences of length N=7 and N=15, show that the proposed system cast effectively indicate the phase of the received code even with very low signal to noise ratios.
{"title":"Neural network based spread spectrum PN code acquisition system","authors":"S. El-Khamy, E. Gelenbe, H. Abdelbaki","doi":"10.1109/NRSC.2000.838959","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838959","url":null,"abstract":"A neural network based direct sequence spread spectrum code synchronization system is proposed. The's system is based on training a recurrent random neural network (RNN) model on all the possible phases of the used spreading code. The trained network can then be used at the receiver for the initial coarse alignment of the local code phase and the received code. One advantage of this technique over the conventional synchronization techniques is that the phase of the received PN code can be decided without searching the potential code phases. Also the RNN, after being trained, can have a simple hardware realization that makes it candidate for implementation as a dedicated chip. This makes the neural network based technique faster and more robust than the conventional techniques. Computer simulations, carried out on maximal length sequences of length N=7 and N=15, show that the proposed system cast effectively indicate the phase of the received code even with very low signal to noise ratios.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122836112","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 : 2000-02-22DOI: 10.1109/NRSC.2000.838962
N. A. Kader
A new algorithm for pitch detection of the speech signal is introduced. The technique is based on the discrete wavelet transform to classify the speech signal into voiced and unvoiced segments. The wavelet parameters of the voiced segments in two frequency bands are extracted and crosscorrelation is performed to generate a correlation function. Then, a peak detection is applied to extract the pitch period. The algorithm is highly immunized to noise. A comparison between the ordinary methods and this new one is presented. The pitch contour is varying through the utterance period rather of being consider as constant through the analysis periods as in ordinary methods. The results are accurate for speech of signal to noise ratio equals to 2 dB.
{"title":"Pitch detection algorithm using a wavelet correlation model","authors":"N. A. Kader","doi":"10.1109/NRSC.2000.838962","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838962","url":null,"abstract":"A new algorithm for pitch detection of the speech signal is introduced. The technique is based on the discrete wavelet transform to classify the speech signal into voiced and unvoiced segments. The wavelet parameters of the voiced segments in two frequency bands are extracted and crosscorrelation is performed to generate a correlation function. Then, a peak detection is applied to extract the pitch period. The algorithm is highly immunized to noise. A comparison between the ordinary methods and this new one is presented. The pitch contour is varying through the utterance period rather of being consider as constant through the analysis periods as in ordinary methods. The results are accurate for speech of signal to noise ratio equals to 2 dB.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2000-02-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126230224","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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