Pub Date : 1996-03-31DOI: 10.1109/SSST.1996.493521
C.P. Liu, A.D. Poularikas
Subband image coding has been shown to be an effective image compression technique for high quality coding at low bit rates. This paper proposes a new subband image compression technique design based on 2-D single-sideband analysis/synthesis system. This new method involves two basic components: the subband analysis/synthesis subsystem, which is composed of down-sampling/up-sampling and filter banks; and the coding subsystem, which utilizes Joint Photographic Experts Group (JPEG) discrete cosine transform lossy transform coder. The first subsystem reduces the image size in the spatial domain and the second subsystem reduces the image size in the frequency domain. These two successive compression processes combine to form a powerful image compression. The overall compression rate of images in this technique can reach up to about 97% of their original size without losing the image quality.
{"title":"A new subband coding technique using (JPEG) discrete cosine transform for image compression","authors":"C.P. Liu, A.D. Poularikas","doi":"10.1109/SSST.1996.493521","DOIUrl":"https://doi.org/10.1109/SSST.1996.493521","url":null,"abstract":"Subband image coding has been shown to be an effective image compression technique for high quality coding at low bit rates. This paper proposes a new subband image compression technique design based on 2-D single-sideband analysis/synthesis system. This new method involves two basic components: the subband analysis/synthesis subsystem, which is composed of down-sampling/up-sampling and filter banks; and the coding subsystem, which utilizes Joint Photographic Experts Group (JPEG) discrete cosine transform lossy transform coder. The first subsystem reduces the image size in the spatial domain and the second subsystem reduces the image size in the frequency domain. These two successive compression processes combine to form a powerful image compression. The overall compression rate of images in this technique can reach up to about 97% of their original size without losing the image quality.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132945121","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 : 1996-03-31DOI: 10.1109/SSST.1996.493492
J. Dorroh, G. Ferreyra, P. Sundar
Describes a change of time technique for stochastic control problems with unbounded control set. The authors demonstrate the technique on a class of maximization problems that do not have optimal controls. Given such a problem, the authors introduce an extended problem which has the same value function as the original problem and for which there exist optimal controls that are expressible in simple terms. This device yields a natural sequence of suboptimal controls for the original problem. By this the authors mean a sequence of controls for which the payoff functions approach the value function.
{"title":"Stochastic problems with unbounded control set","authors":"J. Dorroh, G. Ferreyra, P. Sundar","doi":"10.1109/SSST.1996.493492","DOIUrl":"https://doi.org/10.1109/SSST.1996.493492","url":null,"abstract":"Describes a change of time technique for stochastic control problems with unbounded control set. The authors demonstrate the technique on a class of maximization problems that do not have optimal controls. Given such a problem, the authors introduce an extended problem which has the same value function as the original problem and for which there exist optimal controls that are expressible in simple terms. This device yields a natural sequence of suboptimal controls for the original problem. By this the authors mean a sequence of controls for which the payoff functions approach the value function.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133930531","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 : 1996-03-31DOI: 10.1109/SSST.1996.493524
W. Stapleton, W. Mahmoud, D. J. Jackson
Presented in this paper are experimental results for a parallel implementation of a fractal image compression algorithm. The fractal image compression process exhibits a natural parallelism and the specific parallel implementation is shown to be beneficial for the execution speed of the algorithm. Furthermore, computational speed has been enhanced through an algorithmic modification employing a quadtree recomposition approach in which quadtree subblocks are iteratively combined into larger ranges for fractal encoding. Furthermore, classification schemes which serve to reduce the O(n/sup 4/) algorithmic complexity are explored.
{"title":"A parallel implementation of a fractal image compression algorithm","authors":"W. Stapleton, W. Mahmoud, D. J. Jackson","doi":"10.1109/SSST.1996.493524","DOIUrl":"https://doi.org/10.1109/SSST.1996.493524","url":null,"abstract":"Presented in this paper are experimental results for a parallel implementation of a fractal image compression algorithm. The fractal image compression process exhibits a natural parallelism and the specific parallel implementation is shown to be beneficial for the execution speed of the algorithm. Furthermore, computational speed has been enhanced through an algorithmic modification employing a quadtree recomposition approach in which quadtree subblocks are iteratively combined into larger ranges for fractal encoding. Furthermore, classification schemes which serve to reduce the O(n/sup 4/) algorithmic complexity are explored.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114551540","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 : 1996-03-31DOI: 10.1109/SSST.1996.493533
J. Amiradozi, E. Yaz, K. Olejniczak
The objective of this work is to accommodate the effects of the harmonic signals in power distribution systems. Adaptive output predictors are used to estimate the future values of the load currents based on a finite-memory of past input-output values. The unknown time varying magnitudes and phase angles of harmonics are modeled as the adaptively estimated parameters. Having the predicted load current available in advance, its harmonic content can be identified and the compensation can be done at the correct time with minimum amount of mismatch between the load current and the compensated current. Because of the nonlinear nature of the loads, the harmonics vary continuously. Therefore, the future values of the load current are obtained using adaptive prediction with a specified number of time steps ahead that will be sufficient to carry out the needed compensation. Results of simulation with one, two, and three step ahead predictions are presented.
{"title":"Adaptive compensation of nonlinear loads in power systems","authors":"J. Amiradozi, E. Yaz, K. Olejniczak","doi":"10.1109/SSST.1996.493533","DOIUrl":"https://doi.org/10.1109/SSST.1996.493533","url":null,"abstract":"The objective of this work is to accommodate the effects of the harmonic signals in power distribution systems. Adaptive output predictors are used to estimate the future values of the load currents based on a finite-memory of past input-output values. The unknown time varying magnitudes and phase angles of harmonics are modeled as the adaptively estimated parameters. Having the predicted load current available in advance, its harmonic content can be identified and the compensation can be done at the correct time with minimum amount of mismatch between the load current and the compensated current. Because of the nonlinear nature of the loads, the harmonics vary continuously. Therefore, the future values of the load current are obtained using adaptive prediction with a specified number of time steps ahead that will be sufficient to carry out the needed compensation. Results of simulation with one, two, and three step ahead predictions are presented.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117132562","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 : 1996-03-31DOI: 10.1109/SSST.1996.493465
R. Kurtz, M. A. Henson
A feedback linearization strategy for discrete-time nonlinear systems subject to input constraints is developed and analyzed. The control system comprises: (i) a feedback linearizing controller; (ii) a constraint mapping algorithm that transforms the input constraints into constraints on the feedback linearized system; and (iii) a model predictive controller that regulates the resulting constrained linear system. The stability properties of the proposed control strategy are investigated for both completely and partially feedback linearizable systems.
{"title":"Feedback linearizing control of discrete-time nonlinear systems with constraints","authors":"R. Kurtz, M. A. Henson","doi":"10.1109/SSST.1996.493465","DOIUrl":"https://doi.org/10.1109/SSST.1996.493465","url":null,"abstract":"A feedback linearization strategy for discrete-time nonlinear systems subject to input constraints is developed and analyzed. The control system comprises: (i) a feedback linearizing controller; (ii) a constraint mapping algorithm that transforms the input constraints into constraints on the feedback linearized system; and (iii) a model predictive controller that regulates the resulting constrained linear system. The stability properties of the proposed control strategy are investigated for both completely and partially feedback linearizable systems.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123993624","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 : 1996-03-31DOI: 10.1109/SSST.1996.493464
R. Zachery, Shiheng Wang
This study formulates the single-input-single-output (SISO) output controllability problem based on singular value decomposition (SVD) of the system matrix. With the approach, the authors show if any input trajectory is along a right singular vector, the output trajectory will be along the corresponding left singular vector and will mirror the input. In addition, the authors derive a relationship between zero locations and system matrix minimum singular values /spl sigma//sub min/ and pole locations and system matrix maximum singular values, /spl sigma//sub max/ in the linear discrete time problem.
{"title":"An explanation of linear discrete time system behavior by singular value decomposition of the system matrix","authors":"R. Zachery, Shiheng Wang","doi":"10.1109/SSST.1996.493464","DOIUrl":"https://doi.org/10.1109/SSST.1996.493464","url":null,"abstract":"This study formulates the single-input-single-output (SISO) output controllability problem based on singular value decomposition (SVD) of the system matrix. With the approach, the authors show if any input trajectory is along a right singular vector, the output trajectory will be along the corresponding left singular vector and will mirror the input. In addition, the authors derive a relationship between zero locations and system matrix minimum singular values /spl sigma//sub min/ and pole locations and system matrix maximum singular values, /spl sigma//sub max/ in the linear discrete time problem.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123333472","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 : 1996-03-31DOI: 10.1109/SSST.1996.493466
J.J. Zhu, Wenli Zhu
Pavement roughness is usually characterized by a one figure statistic of pavement profile data. This approach discards a rich body of useful pavement information in the pavement profile data. In this study, informative parametric models for pavement roughness are developed where pavement roughness is treated as a stochastic signal. Based on this stochastic modeling of roughness, a new stochastic roughness index (SRI) is proposed. Case studies conducted on 18 FACE Dipstick profile data and 25 profile data collected using an Ames Profilograph shows that the new SRI, irrespective to the profiling devices, has a good correlation with the International Roughness Index.
{"title":"Stochastic modelling of pavement roughness","authors":"J.J. Zhu, Wenli Zhu","doi":"10.1109/SSST.1996.493466","DOIUrl":"https://doi.org/10.1109/SSST.1996.493466","url":null,"abstract":"Pavement roughness is usually characterized by a one figure statistic of pavement profile data. This approach discards a rich body of useful pavement information in the pavement profile data. In this study, informative parametric models for pavement roughness are developed where pavement roughness is treated as a stochastic signal. Based on this stochastic modeling of roughness, a new stochastic roughness index (SRI) is proposed. Case studies conducted on 18 FACE Dipstick profile data and 25 profile data collected using an Ames Profilograph shows that the new SRI, irrespective to the profiling devices, has a good correlation with the International Roughness Index.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127850000","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 : 1996-03-31DOI: 10.1109/SSST.1996.493559
E. Barbieri, Chia-Chang Tong
In a previous article, a set of five conditions were given to describe the switching hypersurface of the minimum-time, single-axis controller for an undamped, one-mode model of a flexible slewing structure. The purpose of this paper is to show that the five conditions have been found to be reducible to three. This oversight is amended and a new plot of the three conditions in a two-dimensional plane is isolated. This characterization of the switching structure depends only on the rigid-body states, and can be easily used in real-time.
{"title":"Control of a one-mode model on the minimum-time of a flexible structure","authors":"E. Barbieri, Chia-Chang Tong","doi":"10.1109/SSST.1996.493559","DOIUrl":"https://doi.org/10.1109/SSST.1996.493559","url":null,"abstract":"In a previous article, a set of five conditions were given to describe the switching hypersurface of the minimum-time, single-axis controller for an undamped, one-mode model of a flexible slewing structure. The purpose of this paper is to show that the five conditions have been found to be reducible to three. This oversight is amended and a new plot of the three conditions in a two-dimensional plane is isolated. This characterization of the switching structure depends only on the rigid-body states, and can be easily used in real-time.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126176504","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 : 1996-03-31DOI: 10.1109/SSST.1996.493512
D. Bailey, A.A. Beer
We report on the development and performance evaluation of a fixed-point filter simulator for various filter structures and variable wordlength. The simulation models are based on the filter implementation in a Motorola DSP56002 fixed-point DSP. A nonlinear model of DSP56002 multiplier-accumulator including the convergent (unbiased) rounding and saturation is developed. This model is validated by comparison to the actual filter implementation on the DSP56002. These results are also compared to the linear-stochastic rounding noise model and lower bounds. Matlab simulation and automatic scaling routines where developed for the direct form high order, 2nd order cascaded and parallel sections, state-space section optimal, direct form FIR and MA lattice.
{"title":"Simulation of filter structures for fixed-point implementation","authors":"D. Bailey, A.A. Beer","doi":"10.1109/SSST.1996.493512","DOIUrl":"https://doi.org/10.1109/SSST.1996.493512","url":null,"abstract":"We report on the development and performance evaluation of a fixed-point filter simulator for various filter structures and variable wordlength. The simulation models are based on the filter implementation in a Motorola DSP56002 fixed-point DSP. A nonlinear model of DSP56002 multiplier-accumulator including the convergent (unbiased) rounding and saturation is developed. This model is validated by comparison to the actual filter implementation on the DSP56002. These results are also compared to the linear-stochastic rounding noise model and lower bounds. Matlab simulation and automatic scaling routines where developed for the direct form high order, 2nd order cascaded and parallel sections, state-space section optimal, direct form FIR and MA lattice.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115014543","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 : 1996-03-31DOI: 10.1109/SSST.1996.493549
S. Al-Sharaeh, B. Wells
It is not uncommon to evaluate the effectiveness of competing parallel processing scheduling, mapping, and allocation heuristics by applying a common set of randomly-generated task systems and comparing the performance of the resulting allocations in a statistical manner with one another. Although much research has been performed using this paradigm the authors believe that often the results of such experiments have been extrapolated beyond their range of applicability and provide little insight into determining the best heuristic for a given type of real-world problem. This paper presents evidence to support this assertion by analyzing the results of from the mathematical literature (i.e. the P-method and the Box method) to create a large set of directed graphs which are then used (along with a set of digraphs which were derived from real-world problems) to evaluate four classical list-based scheduling methodologies (the HLFET, HLFNET, SCFET, and SCFNET). The difference of the effective ranking of these methodologies from those presented by other researchers illustrate how the built-in biases associated with random techniques can affect how one views the relative effectiveness of each of these heuristics.
{"title":"A comparison of heuristics for list schedules using the Box-method and P-method for random digraph generation","authors":"S. Al-Sharaeh, B. Wells","doi":"10.1109/SSST.1996.493549","DOIUrl":"https://doi.org/10.1109/SSST.1996.493549","url":null,"abstract":"It is not uncommon to evaluate the effectiveness of competing parallel processing scheduling, mapping, and allocation heuristics by applying a common set of randomly-generated task systems and comparing the performance of the resulting allocations in a statistical manner with one another. Although much research has been performed using this paradigm the authors believe that often the results of such experiments have been extrapolated beyond their range of applicability and provide little insight into determining the best heuristic for a given type of real-world problem. This paper presents evidence to support this assertion by analyzing the results of from the mathematical literature (i.e. the P-method and the Box method) to create a large set of directed graphs which are then used (along with a set of digraphs which were derived from real-world problems) to evaluate four classical list-based scheduling methodologies (the HLFET, HLFNET, SCFET, and SCFNET). The difference of the effective ranking of these methodologies from those presented by other researchers illustrate how the built-in biases associated with random techniques can affect how one views the relative effectiveness of each of these heuristics.","PeriodicalId":135973,"journal":{"name":"Proceedings of 28th Southeastern Symposium on System Theory","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"1996-03-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115095807","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：