Pub Date : 2000-02-22DOI: 10.1109/NRSC.2000.838928
M.E. Mostafa, S. Eid
One of the design problems concerning packet switched computer communication networks is the joint optimization of capacity and flow assignment (CFA). In this problem the topology of the network and the traffic requirements between node pairs are given, and the objective is to find the flows on the different links and their capacities that minimize the total network cost and keep its average delay below a certain upper limit. This paper proposes an algorithm based on hybridization of genetic algorithms (GA) and the shortest path routing. The proposed algorithm has shown simplification in implementation and improvement in performance. Computational results indicated a 3.17% reduction in network cost when compared with a previous method.
{"title":"A genetic algorithm for joint optimization of capacity and flow assignment in packet switched networks","authors":"M.E. Mostafa, S. Eid","doi":"10.1109/NRSC.2000.838928","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838928","url":null,"abstract":"One of the design problems concerning packet switched computer communication networks is the joint optimization of capacity and flow assignment (CFA). In this problem the topology of the network and the traffic requirements between node pairs are given, and the objective is to find the flows on the different links and their capacities that minimize the total network cost and keep its average delay below a certain upper limit. This paper proposes an algorithm based on hybridization of genetic algorithms (GA) and the shortest path routing. The proposed algorithm has shown simplification in implementation and improvement in performance. Computational results indicated a 3.17% reduction in network cost when compared with a previous method.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"31 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":"114147761","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":"73 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":"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.2000.838952
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":"3 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":"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.2000.838848
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":"76 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":"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.2000.838957
M. El-Mahy
The use of airborne electronic support measures (ESM) system to detect and track mobile emitters is vital in military operations because of its importance in emitter identification and threat evaluation in a highly dense electromagnetic environment. The aim of this paper is to study whether the three dimensional inputs of azimuth, elevation, and height to an ESM system can detect and track surface mobile emitters at tactically acceptable airborne ESM altitudes. The paper establishes an algorithm that is: (a) non-computationally extensive, (b) can give decision criteria on the transition state of targets from stationary to mobile, and (c) is tactically and operationally acceptable.
{"title":"Mobility detection and tracking of surface emitters at a tactically acceptable airborne ESM altitudes","authors":"M. El-Mahy","doi":"10.1109/NRSC.2000.838957","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838957","url":null,"abstract":"The use of airborne electronic support measures (ESM) system to detect and track mobile emitters is vital in military operations because of its importance in emitter identification and threat evaluation in a highly dense electromagnetic environment. The aim of this paper is to study whether the three dimensional inputs of azimuth, elevation, and height to an ESM system can detect and track surface mobile emitters at tactically acceptable airborne ESM altitudes. The paper establishes an algorithm that is: (a) non-computationally extensive, (b) can give decision criteria on the transition state of targets from stationary to mobile, and (c) is tactically and operationally acceptable.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"71 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":"127096453","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":"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":"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.2000.838943
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":"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":"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.2000.838972
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":"40 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":"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.2000.838969
A. El-Kassas, H. El-Hennawi, R. El-Zanfally, S. Mahrous
In this paper, the effect of multitone jamming (MTJ) on an FHMA/MFSK system is investigated. The channel under consideration is a Rician fading channel, with AWGN included in the analysis. The system capacity is considered as an indicator of the system performance and is calculated for different situations. The capacity is shown to be affected by channel fading state. For no fading, the capacity is 188 users, while with Rician fading it is 108 users and it is 78 users when the fading is Raleigh. The effect of jamming total power was found to have a minor effect on the system capacity. The capacity is affected mainly by number of tones of the multitone jamming (q). When q=2.5% of the frequency hopping bins, the capacity will be 108 users. At q=33% of the hopping frequencies, the capacity decreases to 78 users. When q=50%, the capacity becomes very small (42 users only) compared to the no jamming case.
{"title":"Performance of FHMA, MFSK over Rician fading channel under MTJ","authors":"A. El-Kassas, H. El-Hennawi, R. El-Zanfally, S. Mahrous","doi":"10.1109/NRSC.2000.838969","DOIUrl":"https://doi.org/10.1109/NRSC.2000.838969","url":null,"abstract":"In this paper, the effect of multitone jamming (MTJ) on an FHMA/MFSK system is investigated. The channel under consideration is a Rician fading channel, with AWGN included in the analysis. The system capacity is considered as an indicator of the system performance and is calculated for different situations. The capacity is shown to be affected by channel fading state. For no fading, the capacity is 188 users, while with Rician fading it is 108 users and it is 78 users when the fading is Raleigh. The effect of jamming total power was found to have a minor effect on the system capacity. The capacity is affected mainly by number of tones of the multitone jamming (q). When q=2.5% of the frequency hopping bins, the capacity will be 108 users. At q=33% of the hopping frequencies, the capacity decreases to 78 users. When q=50%, the capacity becomes very small (42 users only) compared to the no jamming case.","PeriodicalId":211510,"journal":{"name":"Proceedings of the Seventeenth National Radio Science Conference. 17th NRSC'2000 (IEEE Cat. No.00EX396)","volume":"36 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":"114773551","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":"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":"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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