Pub Date : 1995-09-05DOI: 10.1109/CCECE.1995.526586
I.J.H. Leung, J. E. Jordan
Image segmentation of weather satellite imagery is an important first step in an automated weather forecasting system. Accurate cloud extraction is also important in the determination of solar radiative transfer in atmospheric research, where satellite observations are used as inputs to global climate models to predict climatic change. Most of the current cloud extraction algorithms tend to be quite complicated to implement and execution time is potentially slow. The authors present a new algorithm which is simple to implement, fast in execution and provides good results in initial tests.
{"title":"Image processing for weather satellite cloud segmentation","authors":"I.J.H. Leung, J. E. Jordan","doi":"10.1109/CCECE.1995.526586","DOIUrl":"https://doi.org/10.1109/CCECE.1995.526586","url":null,"abstract":"Image segmentation of weather satellite imagery is an important first step in an automated weather forecasting system. Accurate cloud extraction is also important in the determination of solar radiative transfer in atmospheric research, where satellite observations are used as inputs to global climate models to predict climatic change. Most of the current cloud extraction algorithms tend to be quite complicated to implement and execution time is potentially slow. The authors present a new algorithm which is simple to implement, fast in execution and provides good results in initial tests.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114204586","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 : 1995-09-05DOI: 10.1109/CCECE.1995.528080
P. Noutsios, G. Yip
An improved vertical coupling structure, consisting of a graded-index planar buried waveguide in glass and a dielectric overlayer, is designed and realized to provide an optimum edge coupling to a modelled GaAs photodetector. Calculations of the attenuation coefficient and coupling efficiency show an optimum absorption behavior. Normal mode measurements and beam propagation calculations of the coupling length and power transfer ratio are compared.
{"title":"Vertically integrated optical directional couplers in glass for improved edge coupling to a thin-film photodetector","authors":"P. Noutsios, G. Yip","doi":"10.1109/CCECE.1995.528080","DOIUrl":"https://doi.org/10.1109/CCECE.1995.528080","url":null,"abstract":"An improved vertical coupling structure, consisting of a graded-index planar buried waveguide in glass and a dielectric overlayer, is designed and realized to provide an optimum edge coupling to a modelled GaAs photodetector. Calculations of the attenuation coefficient and coupling efficiency show an optimum absorption behavior. Normal mode measurements and beam propagation calculations of the coupling length and power transfer ratio are compared.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"120951115","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 : 1995-09-05DOI: 10.1109/CCECE.1995.526580
Xining Li
This paper presents a distributed logic programming language proposal-Communicating Sequential Prolog* (CSP*). CSP* inherits most its features from Prolog and provides a process-oriented programming environment for distributed discrete event simulations. We discuss some language issues and programming examples to reveal the simplicity, flexibility, and the expressivity.
{"title":"Distributed simulation in CSP*","authors":"Xining Li","doi":"10.1109/CCECE.1995.526580","DOIUrl":"https://doi.org/10.1109/CCECE.1995.526580","url":null,"abstract":"This paper presents a distributed logic programming language proposal-Communicating Sequential Prolog* (CSP*). CSP* inherits most its features from Prolog and provides a process-oriented programming environment for distributed discrete event simulations. We discuss some language issues and programming examples to reveal the simplicity, flexibility, and the expressivity.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121381463","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 : 1995-09-05DOI: 10.1109/CCECE.1995.528202
K. Idir, Liuchen Chang
This paper presents an investigation into the effects of the positions of ventilation holes and mounting holes on the magnetic field of a 1130 kVA synchronous generator, using two-dimensional finite element analysis. The flux densities in the stator yoke, stator teeth and airgap are determined for various positions of ventilation holes and mounting holes. The results of the study are presented and discussed. These results provide technical support to machine design, in particular the calculation of magnetization current.
{"title":"The effects of ventilation and mounting holes on the magnetic field of a synchronous generator","authors":"K. Idir, Liuchen Chang","doi":"10.1109/CCECE.1995.528202","DOIUrl":"https://doi.org/10.1109/CCECE.1995.528202","url":null,"abstract":"This paper presents an investigation into the effects of the positions of ventilation holes and mounting holes on the magnetic field of a 1130 kVA synchronous generator, using two-dimensional finite element analysis. The flux densities in the stator yoke, stator teeth and airgap are determined for various positions of ventilation holes and mounting holes. The results of the study are presented and discussed. These results provide technical support to machine design, in particular the calculation of magnetization current.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"22 6S 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133266841","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 : 1995-09-05DOI: 10.1109/CCECE.1995.526562
M. C. Ghanem, K. Al-haddad, G. Roy
The main objective of this work is a comparison of three nonpollutant AC-DC convertor topologies with unity power factor and high efficiency, in order to derive maximum benefit from the assembly utilised while ensuring AC/DC conversion. Discussion of the principle of comparison is followed by a detailed analysis and tables showing the advantages and disadvantages of each convertor. The results of simulation of the three proposed convertors are presented.
{"title":"Comparative study of AC/DC convertors with unity power factor","authors":"M. C. Ghanem, K. Al-haddad, G. Roy","doi":"10.1109/CCECE.1995.526562","DOIUrl":"https://doi.org/10.1109/CCECE.1995.526562","url":null,"abstract":"The main objective of this work is a comparison of three nonpollutant AC-DC convertor topologies with unity power factor and high efficiency, in order to derive maximum benefit from the assembly utilised while ensuring AC/DC conversion. Discussion of the principle of comparison is followed by a detailed analysis and tables showing the advantages and disadvantages of each convertor. The results of simulation of the three proposed convertors are presented.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"142 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133928576","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 : 1995-09-05DOI: 10.1109/CCECE.1995.526310
G. Zhao, F. Ghannouchi, F. Beauregard
The input average power and peak power for different numbers of multiple channels are estimated for power amplifiers operated in CDMA-based PCS down-link transmitters. Multiple QPSK spread spectrum signals have been simulated, using SPW software (signal processing worksystem). The simulation results for N/spl les/64 are given. The obtained dynamic range requirements are useful for linear power amplifiers designed for CDMA-PCS application.
{"title":"Dynamic range requirements for CDMA-based PCS power amplifiers","authors":"G. Zhao, F. Ghannouchi, F. Beauregard","doi":"10.1109/CCECE.1995.526310","DOIUrl":"https://doi.org/10.1109/CCECE.1995.526310","url":null,"abstract":"The input average power and peak power for different numbers of multiple channels are estimated for power amplifiers operated in CDMA-based PCS down-link transmitters. Multiple QPSK spread spectrum signals have been simulated, using SPW software (signal processing worksystem). The simulation results for N/spl les/64 are given. The obtained dynamic range requirements are useful for linear power amplifiers designed for CDMA-PCS application.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"610 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114091262","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 : 1995-09-05DOI: 10.1109/CCECE.1995.526289
J. Belzile, F. Gagnon, D. Haccoun
In this paper the performance of convolutional decoding over fading channels is explored, The decoding algorithm used are the Viterbi and bidirectional algorithms. By estimating a "decoder weight spectrum" for the decoder, an "equivalent free distance" may be observed. Furthermore, using this "decoder weight spectrum" useful estimations of the error probabilities are obtained and compared to computer simulation results in the case of very slow and very fast fading. The resultant curves are shown to be very tightly related.
{"title":"Fading channel performance analysis for the decoding of convolutional codes","authors":"J. Belzile, F. Gagnon, D. Haccoun","doi":"10.1109/CCECE.1995.526289","DOIUrl":"https://doi.org/10.1109/CCECE.1995.526289","url":null,"abstract":"In this paper the performance of convolutional decoding over fading channels is explored, The decoding algorithm used are the Viterbi and bidirectional algorithms. By estimating a \"decoder weight spectrum\" for the decoder, an \"equivalent free distance\" may be observed. Furthermore, using this \"decoder weight spectrum\" useful estimations of the error probabilities are obtained and compared to computer simulation results in the case of very slow and very fast fading. The resultant curves are shown to be very tightly related.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125047060","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 : 1995-09-05DOI: 10.1109/CCECE.1995.526612
M. Zilovic, R. Ramachandran, R. Mammone
A common problem in speaker identification systems is that a mismatch in the training and testing conditions sacrifices much performance. The authors attempt to alleviate this problem by proposing new features that show less variation when speech is corrupted by convolutional noise (channel) and/or additive noise. The conventional feature used is the linear predictive (LP) cepstrum that is derived from an all-pole transfer function which in turn achieves a good approximation to the spectral envelope of the speech. Previously, a new cepstral feature based on a pole-zero function (called the adaptive component weighted or ACW cepstrum) was introduced. The present authors propose two additional new cepstral features based on pole-zero transfer functions. One is an alternative way of doing adaptive component weighting and is called the ACW2 cepstrum. The other (known as the PFL1 cepstrum) is based on a pole-zero postfilter used in speech enhancement. Experiments involving a closed set, text-independent and vector quantizer based speaker identification system are done to compare the various features. The King database is used. The ACW and PFL1 features are generally the best. The corresponding spectra show a clear emphasis of the formants and no spectral tilt. To enhance robustness, it is important to emphasize the formants. An accurate description of the spectral envelope is not required.
{"title":"The use of robust cepstral features obtained from pole-zero transfer functions for speaker identification","authors":"M. Zilovic, R. Ramachandran, R. Mammone","doi":"10.1109/CCECE.1995.526612","DOIUrl":"https://doi.org/10.1109/CCECE.1995.526612","url":null,"abstract":"A common problem in speaker identification systems is that a mismatch in the training and testing conditions sacrifices much performance. The authors attempt to alleviate this problem by proposing new features that show less variation when speech is corrupted by convolutional noise (channel) and/or additive noise. The conventional feature used is the linear predictive (LP) cepstrum that is derived from an all-pole transfer function which in turn achieves a good approximation to the spectral envelope of the speech. Previously, a new cepstral feature based on a pole-zero function (called the adaptive component weighted or ACW cepstrum) was introduced. The present authors propose two additional new cepstral features based on pole-zero transfer functions. One is an alternative way of doing adaptive component weighting and is called the ACW2 cepstrum. The other (known as the PFL1 cepstrum) is based on a pole-zero postfilter used in speech enhancement. Experiments involving a closed set, text-independent and vector quantizer based speaker identification system are done to compare the various features. The King database is used. The ACW and PFL1 features are generally the best. The corresponding spectra show a clear emphasis of the formants and no spectral tilt. To enhance robustness, it is important to emphasize the formants. An accurate description of the spectral envelope is not required.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"8 3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123526185","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 : 1995-09-05DOI: 10.1109/CCECE.1995.528066
M. El-Tarhuni, A. Sheikh
The performance of a direct sequence spread spectrum (DS-SS) code division multiple access (CDMA) communications systems is highly dependent upon the set of spreading sequences used in these systems. The multiple access interference could become very large if the spreading sequences are not carefully selected. A new numerical optimization procedure is proposed for the selection of spreading sequences based on minimizing the interference parameter among the sequences. The improvement in the average output signal-to-noise ratio or CDMA capacity improvement is used to compare the performance of the optimized code set with that of the set of Gold codes of the same length. An improvement of about 26% in the system capacity is obtained. Also, construction of different optimized code sets suitable for use in cellular systems applications is considered.
{"title":"Numerical optimization for CDMA spreading sequences","authors":"M. El-Tarhuni, A. Sheikh","doi":"10.1109/CCECE.1995.528066","DOIUrl":"https://doi.org/10.1109/CCECE.1995.528066","url":null,"abstract":"The performance of a direct sequence spread spectrum (DS-SS) code division multiple access (CDMA) communications systems is highly dependent upon the set of spreading sequences used in these systems. The multiple access interference could become very large if the spreading sequences are not carefully selected. A new numerical optimization procedure is proposed for the selection of spreading sequences based on minimizing the interference parameter among the sequences. The improvement in the average output signal-to-noise ratio or CDMA capacity improvement is used to compare the performance of the optimized code set with that of the set of Gold codes of the same length. An improvement of about 26% in the system capacity is obtained. Also, construction of different optimized code sets suitable for use in cellular systems applications is considered.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"34 6","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"113967498","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 : 1995-09-05DOI: 10.1109/CCECE.1995.528115
M. Alie, J. Belzile, C. Thibeault
The authors propose a modification of the M-path convolutional code decoding algorithm in order to improve its performance. Due to nonexhaustive exploration of the trellis, the M-path algorithm is a suboptimal decoding algorithm. On the other hand, this elimination of certain paths from the trellis reduces its complexity in comparison with the Viterbi algorithm. The proposed modification adds to the traditional calculation of the branch metric an algebraic metric representing an estimate of the number of future symbol errors. By this new metric the performance of the M-path decoder is improved by about 0.5 dB.
{"title":"M-path decoder with algebraic metric calculation","authors":"M. Alie, J. Belzile, C. Thibeault","doi":"10.1109/CCECE.1995.528115","DOIUrl":"https://doi.org/10.1109/CCECE.1995.528115","url":null,"abstract":"The authors propose a modification of the M-path convolutional code decoding algorithm in order to improve its performance. Due to nonexhaustive exploration of the trellis, the M-path algorithm is a suboptimal decoding algorithm. On the other hand, this elimination of certain paths from the trellis reduces its complexity in comparison with the Viterbi algorithm. The proposed modification adds to the traditional calculation of the branch metric an algebraic metric representing an estimate of the number of future symbol errors. By this new metric the performance of the M-path decoder is improved by about 0.5 dB.","PeriodicalId":158581,"journal":{"name":"Proceedings 1995 Canadian Conference on Electrical and Computer Engineering","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1995-09-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121576476","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}
京公网安备 11010802042870号
京ICP备2023020795号-1
扫码关注我们
求助内容：
应助结果提醒方式：