Pub Date : 1991-05-14DOI: 10.1109/MWSCAS.1991.251974
J. Zhu, J. Han, A. Hurson
The authors present a decentralized architecture for a multiprocessor database machine which supports multiple-user, online, very large relational database systems. A corresponding processor allocation strategy is proposed which applies the dataflow technique to distribute processors across all nodes of the vertically layered query tree and to pipeline pages of intermediate relation between them. Simulations show that the query execution time is 20%-25% less than that in the DIRECT database machine. The time used to process the messages in the authors' database machine is almost 40% less than the time used in DIRECT. The simulation also indicated that the machine's structure is less sensitive to the I/O bound than the DIRECT machine.<>
{"title":"A multiprocessor organization for very large relational database","authors":"J. Zhu, J. Han, A. Hurson","doi":"10.1109/MWSCAS.1991.251974","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.251974","url":null,"abstract":"The authors present a decentralized architecture for a multiprocessor database machine which supports multiple-user, online, very large relational database systems. A corresponding processor allocation strategy is proposed which applies the dataflow technique to distribute processors across all nodes of the vertically layered query tree and to pipeline pages of intermediate relation between them. Simulations show that the query execution time is 20%-25% less than that in the DIRECT database machine. The time used to process the messages in the authors' database machine is almost 40% less than the time used in DIRECT. The simulation also indicated that the machine's structure is less sensitive to the I/O bound than the DIRECT machine.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"41 1","pages":"970-973 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88740381","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 : 1991-05-14DOI: 10.1109/MWSCAS.1991.252003
T. S. Parker
The author presents INSITE, a user-friendly, graphically oriented collection of interactive programs for the simulation of nonlinear dynamics, with an emphasis on chaotic systems. INSITE comprises programs that calculate trajectories, periodic solutions, bifurcation diagrams, Lyapunov exponents, correlation dimension, complete phase portraits of two-dimensional autonomous systems, and one-dimensional invariant manifolds of a map. INSITE runs under both the Unix and DOS operating systems.<>
{"title":"INSITE: a software toolkit for studying chaos","authors":"T. S. Parker","doi":"10.1109/MWSCAS.1991.252003","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.252003","url":null,"abstract":"The author presents INSITE, a user-friendly, graphically oriented collection of interactive programs for the simulation of nonlinear dynamics, with an emphasis on chaotic systems. INSITE comprises programs that calculate trajectories, periodic solutions, bifurcation diagrams, Lyapunov exponents, correlation dimension, complete phase portraits of two-dimensional autonomous systems, and one-dimensional invariant manifolds of a map. INSITE runs under both the Unix and DOS operating systems.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"13 1","pages":"752-755 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87180098","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 : 1991-05-14DOI: 10.1109/MWSCAS.1991.252158
E.A.F. Abdalla, E. Hosny, M. A. Nassef, A. M. Moselhy
A modified extrapolation method is presented to overcome the difficulty produced by using the least square approximation in the extrapolation method. The method has been implemented on lumped nonlinear and linear networks. The algorithm is shown to be very effective in reducing the amount of computation necessary for the steady-state solution of a nonlinear lumped circuit without the need for the least square approximation. In the case of linear lumped circuits with high Q, the algorithm is very effective in reducing the computation time with a very small error.<>
{"title":"Fast computation of the steady state solution of nonlinear networks by a modified extrapolation algorithm","authors":"E.A.F. Abdalla, E. Hosny, M. A. Nassef, A. M. Moselhy","doi":"10.1109/MWSCAS.1991.252158","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.252158","url":null,"abstract":"A modified extrapolation method is presented to overcome the difficulty produced by using the least square approximation in the extrapolation method. The method has been implemented on lumped nonlinear and linear networks. The algorithm is shown to be very effective in reducing the amount of computation necessary for the steady-state solution of a nonlinear lumped circuit without the need for the least square approximation. In the case of linear lumped circuits with high Q, the algorithm is very effective in reducing the computation time with a very small error.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"11 1","pages":"195-197 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91175692","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 : 1991-05-14DOI: 10.1109/MWSCAS.1991.251943
D. Hummels, J. Ying
The authors address the application of locally optimum (LO) signal detection techniques to environments in which there is no prior knowledge of the noise density and spectral properties. Specific algorithms are introduced, and the performance of these algorithms is examined. Unlike previous algorithms, these techniques place few assumptions on the properties of the noise, and they perform well under a wide variety of circumstances. The algorithms presented were tested using noise with Cauchy, Laplace, and Gaussian mixture density functions. In all cases the LO procedures showed significant improvement over the direct use of the magnitude of the DFT (discrete Fourier transform), at least for small signal levels. In general, the results were most dramatic when testing with noise densities with very heavy tails, such as the Cauchy and Gaussian mixture cases.<>
{"title":"Locally optimal detection of unknown signals in non-Gaussian Markov noise","authors":"D. Hummels, J. Ying","doi":"10.1109/MWSCAS.1991.251943","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.251943","url":null,"abstract":"The authors address the application of locally optimum (LO) signal detection techniques to environments in which there is no prior knowledge of the noise density and spectral properties. Specific algorithms are introduced, and the performance of these algorithms is examined. Unlike previous algorithms, these techniques place few assumptions on the properties of the noise, and they perform well under a wide variety of circumstances. The algorithms presented were tested using noise with Cauchy, Laplace, and Gaussian mixture density functions. In all cases the LO procedures showed significant improvement over the direct use of the magnitude of the DFT (discrete Fourier transform), at least for small signal levels. In general, the results were most dramatic when testing with noise densities with very heavy tails, such as the Cauchy and Gaussian mixture cases.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"11 1","pages":"1098-1101 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90852783","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 : 1991-05-14DOI: 10.1109/MWSCAS.1991.252169
M. Robinson, J. Ramírez-Angulo, E. Sánchez-Sinencio
Two different ways of implementing current-mode analog signal filtering are proposed. A practical comparison of filter structures using programmable current mirrors and single transistors as current integrators versus filters using an approach involving transconductors and current replica circuits is presented. Experimental results for a bandpass filter using the current mirror approach are presented and discussed.<>
{"title":"Current-mode continuous-time filters: two design approaches","authors":"M. Robinson, J. Ramírez-Angulo, E. Sánchez-Sinencio","doi":"10.1109/MWSCAS.1991.252169","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.252169","url":null,"abstract":"Two different ways of implementing current-mode analog signal filtering are proposed. A practical comparison of filter structures using programmable current mirrors and single transistors as current integrators versus filters using an approach involving transconductors and current replica circuits is presented. Experimental results for a bandpass filter using the current mirror approach are presented and discussed.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"31 1","pages":"352-355 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90433734","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 : 1991-05-14DOI: 10.1109/MWSCAS.1991.251945
C. Lindquist, M. K. Awang
The authors discuss separating and detecting signals which are combined multiplicatively where the system input is the product of the signal and the noise or the unwanted component. This system can be applied to amplitude modulation, fading channels, audio dynamic range compression and expansion, automatic gain control, radar, sonar, image enhancement, and music applications. When either the model for the signal expectation spectrum or that for the noise expectation spectrum, but not both, is known a priori, the Class 2 algorithm has to be used. The unknown spectral model must be explicitly estimated a posteriori from the ideal filter input. Optimum estimation and detection filters are developed by using homomorphic techniques to separate these signals.<>
{"title":"Class 2 homomorphic estimation and detection of multiplicatively-combined signals","authors":"C. Lindquist, M. K. Awang","doi":"10.1109/MWSCAS.1991.251945","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.251945","url":null,"abstract":"The authors discuss separating and detecting signals which are combined multiplicatively where the system input is the product of the signal and the noise or the unwanted component. This system can be applied to amplitude modulation, fading channels, audio dynamic range compression and expansion, automatic gain control, radar, sonar, image enhancement, and music applications. When either the model for the signal expectation spectrum or that for the noise expectation spectrum, but not both, is known a priori, the Class 2 algorithm has to be used. The unknown spectral model must be explicitly estimated a posteriori from the ideal filter input. Optimum estimation and detection filters are developed by using homomorphic techniques to separate these signals.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"9 1","pages":"1090-1093 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88458804","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 : 1991-05-14DOI: 10.1109/MWSCAS.1991.251996
G. Moon, M. Zaghloul, R. Newcomb
A CMOS integrated circuit for the weighted synapse and the summation of the synaptic signals is presented. Neural-type cells (NTCs) are used as the processing elements along with a voltage-controlled linear MOS resistor. This variable resistor is used to control the synaptic weights as pulse densities, and thus the weights are controlled by the gate control voltage. By adding buffered inverter stages, the output signal of the NTC is converted into the normalized pulse stream of the 5 V/sub p-p/ signal for easy handling. The summation is executed by a capacitor integration circuit where the currents from different NTCs are accumulated. Simulation results are presented.<>
{"title":"VLSI implementation of neural-type cell with MOS linear resistor","authors":"G. Moon, M. Zaghloul, R. Newcomb","doi":"10.1109/MWSCAS.1991.251996","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.251996","url":null,"abstract":"A CMOS integrated circuit for the weighted synapse and the summation of the synaptic signals is presented. Neural-type cells (NTCs) are used as the processing elements along with a voltage-controlled linear MOS resistor. This variable resistor is used to control the synaptic weights as pulse densities, and thus the weights are controlled by the gate control voltage. By adding buffered inverter stages, the output signal of the NTC is converted into the normalized pulse stream of the 5 V/sub p-p/ signal for easy handling. The summation is executed by a capacitor integration circuit where the currents from different NTCs are accumulated. Simulation results are presented.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"41 1","pages":"784-787 vol.2"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84853087","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 : 1991-05-14DOI: 10.1109/MWSCAS.1991.252178
F. Moll, E. Isern, E. Sicard, A. Rubio
Shows how crosstalk coupling between signals with concurrent transitions can cause a significant increase in or a reduction of the propagation delay of CMOS logic cells connected to them. A reduced model for parasitic capacitive coupling is proposed, and the influence of electrical cell parameters on the internal delay is evaluated. As an application example, the authors analyze how an enlarged delay due to crosstalk can cause permanent logic faults in RS latch circuits.<>
{"title":"Analysis of cross-talk effects on logic cell delays in CMOS integrated circuits","authors":"F. Moll, E. Isern, E. Sicard, A. Rubio","doi":"10.1109/MWSCAS.1991.252178","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.252178","url":null,"abstract":"Shows how crosstalk coupling between signals with concurrent transitions can cause a significant increase in or a reduction of the propagation delay of CMOS logic cells connected to them. A reduced model for parasitic capacitive coupling is proposed, and the influence of electrical cell parameters on the internal delay is evaluated. As an application example, the authors analyze how an enlarged delay due to crosstalk can cause permanent logic faults in RS latch circuits.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"34 1","pages":"387-390 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"87212640","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 : 1991-05-14DOI: 10.1109/MWSCAS.1991.252061
D. Johns, D. Lewis
A design methodology for realizing IIR (infinite impulse response) filters on sigma-delta modulated signals is proposed. It is shown that only 3N adders together with minor logic are required to implement an Nth-order filter. With the use of examples, it is also shown that a linear noise analysis gives an excellent prediction of noise performance over the frequency band of interest. This type of filtering should prove useful in VLSI technologies where interfaces to analog signals are required. To demonstrate the validity of this approach, a fifth-order prototype filter was simulated for three different oversampling ratios.<>
{"title":"Sigma-delta based IIR filters","authors":"D. Johns, D. Lewis","doi":"10.1109/MWSCAS.1991.252061","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.252061","url":null,"abstract":"A design methodology for realizing IIR (infinite impulse response) filters on sigma-delta modulated signals is proposed. It is shown that only 3N adders together with minor logic are required to implement an Nth-order filter. With the use of examples, it is also shown that a linear noise analysis gives an excellent prediction of noise performance over the frequency band of interest. This type of filtering should prove useful in VLSI technologies where interfaces to analog signals are required. To demonstrate the validity of this approach, a fifth-order prototype filter was simulated for three different oversampling ratios.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"28 1","pages":"210-213 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76725071","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 : 1991-05-14DOI: 10.1109/MWSCAS.1991.252051
J. Bedi, M.Z. Dawood, R. Iqbal
The use of variable-length code to achieve the optimum data rate is suggested. A comma insertion scheme is recommended to circumvent the limitation of loss of synchronization in variable-length coding. Algorithms are given to calculate the expected error span due to single or multiple bit inversions. A numerical approach is developed and simulated to determine error span for single bit inversion, and results are compared with previous results.<>
{"title":"Simulation of comma free synchronization scheme and expected error span in variable length codes","authors":"J. Bedi, M.Z. Dawood, R. Iqbal","doi":"10.1109/MWSCAS.1991.252051","DOIUrl":"https://doi.org/10.1109/MWSCAS.1991.252051","url":null,"abstract":"The use of variable-length code to achieve the optimum data rate is suggested. A comma insertion scheme is recommended to circumvent the limitation of loss of synchronization in variable-length coding. Algorithms are given to calculate the expected error span due to single or multiple bit inversions. A numerical approach is developed and simulated to determine error span for single bit inversion, and results are compared with previous results.<<ETX>>","PeriodicalId":6453,"journal":{"name":"[1991] Proceedings of the 34th Midwest Symposium on Circuits and Systems","volume":"137 1","pages":"253-256 vol.1"},"PeriodicalIF":0.0,"publicationDate":"1991-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76777540","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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