Pub Date : 2010-03-07DOI: 10.1109/SSST.2010.5442805
Sandeep Narkimelli, H. Ochoa
Radar is a device which detects distant or non visible objects by means of reflected radio waves [1]. The quality of the reflected signal depends on the shape and orientation of the target with respect to the type of polarization used. Most of the antennas currently used on radar systems employ one type of polarization at a time for target detection. This paper describes the importance of employing polarizations of multiple angles on targets, approximately at the same instant of time. To implement this idea a generalized set of equations have been derived which represent the backscatter generated by a cylindrical object. Using different angles in these equations would give the backscatters of different polarizations employed on the same target, at small time intervals. The logic behind this is that there would be at least one angle that would have the maximum signal strength in the backscatter. The backscatter for this angle would satisfy the best quality criterion as compared with the rest of the polarization angles.
{"title":"Scattering of electromagnetic radiation for a perfect electric conducting cylinder by using multiple angles of polarization","authors":"Sandeep Narkimelli, H. Ochoa","doi":"10.1109/SSST.2010.5442805","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442805","url":null,"abstract":"Radar is a device which detects distant or non visible objects by means of reflected radio waves [1]. The quality of the reflected signal depends on the shape and orientation of the target with respect to the type of polarization used. Most of the antennas currently used on radar systems employ one type of polarization at a time for target detection. This paper describes the importance of employing polarizations of multiple angles on targets, approximately at the same instant of time. To implement this idea a generalized set of equations have been derived which represent the backscatter generated by a cylindrical object. Using different angles in these equations would give the backscatters of different polarizations employed on the same target, at small time intervals. The logic behind this is that there would be at least one angle that would have the maximum signal strength in the backscatter. The backscatter for this angle would satisfy the best quality criterion as compared with the rest of the polarization angles.","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"83087234","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 : 2010-03-07DOI: 10.1109/SSST.2010.5442794
John M. Davis, I. Gravagne, Billy Jackson, R. Marks
A fundamental result in linear system theory is the development of a linear state feedback stabilizer for time-varying systems under suitable controllability constraints. This result was previously restricted to systems operating on the continuous (R) and uniform discrete (hZ) time domains with constant step size h. Using the framework of dynamic equations on time scales, we construct a linear state feedback stabilizer for time-varying systems on arbitrary time domains1.
{"title":"State feedback stabilization of linear time-varying systems on time scales","authors":"John M. Davis, I. Gravagne, Billy Jackson, R. Marks","doi":"10.1109/SSST.2010.5442794","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442794","url":null,"abstract":"A fundamental result in linear system theory is the development of a linear state feedback stabilizer for time-varying systems under suitable controllability constraints. This result was previously restricted to systems operating on the continuous (R) and uniform discrete (hZ) time domains with constant step size h. Using the framework of dynamic equations on time scales, we construct a linear state feedback stabilizer for time-varying systems on arbitrary time domains1.","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84308262","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 : 2010-03-07DOI: 10.1109/SSST.2010.5442802
R. Munasinghe, A. Davari
Standard edge detectors such as Canny edge detector use a local gradient operator to find the ridges in digital images. In this study we show that peer groups and neighbor groups, a new measure introduced in this paper, can be used to improve the performance of gradient operators. Some of the pixels near the threshold are weaker edge pixels of the objects in the image and others are unimportant edges created by unevenness of the background. We find that peer groups and neighbor groups of these marginal pixels can be used to make a better decision regarding them than using a single rigid threshold value.
{"title":"Peer groups, neighbor groups, and edge detection","authors":"R. Munasinghe, A. Davari","doi":"10.1109/SSST.2010.5442802","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442802","url":null,"abstract":"Standard edge detectors such as Canny edge detector use a local gradient operator to find the ridges in digital images. In this study we show that peer groups and neighbor groups, a new measure introduced in this paper, can be used to improve the performance of gradient operators. Some of the pixels near the threshold are weaker edge pixels of the objects in the image and others are unimportant edges created by unevenness of the background. We find that peer groups and neighbor groups of these marginal pixels can be used to make a better decision regarding them than using a single rigid threshold value.","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73988673","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 : 2010-03-07DOI: 10.1109/SSST.2010.5442804
Sai sri Krishna Haridass, D. Hoe
Block Based Neural Networks (BBNNs) have shown to be a practical means for implementing evolvable hardware on reconfigurable fabrics for solving a variety of problems that take advantage of the massive parallelism offered by a neural network approach. This paper proposes a method for obtaining a fault tolerant implementation of BBNNs by using a biologically inspired layered design. At the lowest level, each block has its own online detection and correcting logic combined with sufficient spare components to ensure recovery from permanent and transient errors. Another layer of hierarchy combines the blocks into clusters, where a redundant column of blocks can be used to replace blocks that cannot be repaired at the lowest level. The hierarchical approach is well-suited to a divide-and-conquer approach to genetic programming whereby complex problems are subdivided into smaller parts. The overall approach can be implemented on a reconfigurable fabric.
{"title":"Fault tolerant Block Based Neural Networks","authors":"Sai sri Krishna Haridass, D. Hoe","doi":"10.1109/SSST.2010.5442804","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442804","url":null,"abstract":"Block Based Neural Networks (BBNNs) have shown to be a practical means for implementing evolvable hardware on reconfigurable fabrics for solving a variety of problems that take advantage of the massive parallelism offered by a neural network approach. This paper proposes a method for obtaining a fault tolerant implementation of BBNNs by using a biologically inspired layered design. At the lowest level, each block has its own online detection and correcting logic combined with sufficient spare components to ensure recovery from permanent and transient errors. Another layer of hierarchy combines the blocks into clusters, where a redundant column of blocks can be used to replace blocks that cannot be repaired at the lowest level. The hierarchical approach is well-suited to a divide-and-conquer approach to genetic programming whereby complex problems are subdivided into smaller parts. The overall approach can be implemented on a reconfigurable fabric.","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90099576","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 : 2010-03-07DOI: 10.1109/SSST.2010.5442789
Babu Hemanth Kumar Aswathappa, K. Rao
In this paper we employ Structural Similarity Index (SSIM) metric in the rate-distortion optimizations of H.264 strictly I-frame encoder to choose the best prediction mode(s). The SSIM is designed to improve on traditional metrics like PSNR and MSE, which have been proved to be inconsistent with human eye perception. The required modifications are done on the JVT reference software JM92 program. The simulation results show that there is reduction in bit rate by 3% while maintaining almost the same video quality and better encoding time
{"title":"Rate-distortion optimization using structural information in H.264 strictly Intra-frame encoder","authors":"Babu Hemanth Kumar Aswathappa, K. Rao","doi":"10.1109/SSST.2010.5442789","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442789","url":null,"abstract":"In this paper we employ Structural Similarity Index (SSIM) metric in the rate-distortion optimizations of H.264 strictly I-frame encoder to choose the best prediction mode(s). The SSIM is designed to improve on traditional metrics like PSNR and MSE, which have been proved to be inconsistent with human eye perception. The required modifications are done on the JVT reference software JM92 program. The simulation results show that there is reduction in bit rate by 3% while maintaining almost the same video quality and better encoding time","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88874132","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 : 2010-03-07DOI: 10.1109/SSST.2010.5442852
R. Barsanti
This paper investigates the application of wavelet noise removal techniques to digital baseband signals. Non-linear filtering in the wavelet domain is used to improve the performance of the standard time domain correlation process for these signals. The proposed wavelet-based receiver computes the normalized cross correlation between the filtered wavelet coefficients of the received signal and wavelet coefficients that correspond to the known transmitted digital signals. Simulations are conducted comparing the wavelet receiver to the classical matched receiver.
{"title":"Wavelet noise removal from baseband digital signals in bandlimited channels","authors":"R. Barsanti","doi":"10.1109/SSST.2010.5442852","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442852","url":null,"abstract":"This paper investigates the application of wavelet noise removal techniques to digital baseband signals. Non-linear filtering in the wavelet domain is used to improve the performance of the standard time domain correlation process for these signals. The proposed wavelet-based receiver computes the normalized cross correlation between the filtered wavelet coefficients of the received signal and wavelet coefficients that correspond to the known transmitted digital signals. Simulations are conducted comparing the wavelet receiver to the classical matched receiver.","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"91406848","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 : 2010-03-07DOI: 10.1109/SSST.2010.5442838
A. Eid, H. El-kishky, M. Abdel-Salam, T. El-Mohandes
A three-phase three-wire shunt active power filter (APF) is presented to regulate the load terminal voltage, eliminate harmonics, correct supply power-factor and balance the nonlinear unbalanced loads. A three-phase based current controlled voltage source inverter is used as an active power filter. The control algorithm for the APF is based on the perfect harmonic cancellation method which provides a three-phase reference supply current in phase with its positive sequence fundamental voltage component. The APF is used in the 90-kVA advanced aircraft electric power system under variable-speed constant-frequency (VSCF) operation. The generator output voltage frequency is varied from 400-Hz to 800-Hz for different loading case-studies. Non-linear DC loads are included in the simulation of the aircraft system in addition to the different passive and dynamic loads. The power quality of the studied aircraft electric system is shown to comply with the newly aircraft electrical standards MIL-STD-704F and the IEEE-std 519.
{"title":"VSCF aircraft electric power system performance with active power filters","authors":"A. Eid, H. El-kishky, M. Abdel-Salam, T. El-Mohandes","doi":"10.1109/SSST.2010.5442838","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442838","url":null,"abstract":"A three-phase three-wire shunt active power filter (APF) is presented to regulate the load terminal voltage, eliminate harmonics, correct supply power-factor and balance the nonlinear unbalanced loads. A three-phase based current controlled voltage source inverter is used as an active power filter. The control algorithm for the APF is based on the perfect harmonic cancellation method which provides a three-phase reference supply current in phase with its positive sequence fundamental voltage component. The APF is used in the 90-kVA advanced aircraft electric power system under variable-speed constant-frequency (VSCF) operation. The generator output voltage frequency is varied from 400-Hz to 800-Hz for different loading case-studies. Non-linear DC loads are included in the simulation of the aircraft system in addition to the different passive and dynamic loads. The power quality of the studied aircraft electric system is shown to comply with the newly aircraft electrical standards MIL-STD-704F and the IEEE-std 519.","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79541414","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 : 2010-03-07DOI: 10.1109/SSST.2010.5442830
R. Roberts, S. Siddiqui, A. A. Maciejewski
In environments that are remote and hazardous, tasks such as repairing and maintaining a robot manipulator can be extremely difficult and costly. Under such conditions, the operational reliability of a robotic system is very important and motivates the problem of designing optimally fault-tolerant manipulators. One solution to increasing the fault tolerance of a robotic system is to use kinematically redundant manipulators, as their extra degree of redundancy could be used to compensate for the failure in joint actuators. However, simply adding kinematic redundancy does not guarantee fault tolerance, rather it should be strategically added to ensure optimally fault-tolerant system. In this article the authors design nominal manipulator Jacobians that are optimally fault-tolerant to multiple joint failures. The special case when the manipulator is equally fault-tolerant to any two simultaneous joint failures is considered. While it is possible to design a six degree-of-freedom (DOF) robot manipulator to be equally fault-tolerant to any two simultaneous joint failures for three-dimensional workspaces, it is shown that no manipulator operating in a 4 or 5 dimensional workspace can be equally fault-tolerant to two failures.
{"title":"On the limitations of designing equally fault-tolerant configurations for kinematically redundant manipulators","authors":"R. Roberts, S. Siddiqui, A. A. Maciejewski","doi":"10.1109/SSST.2010.5442830","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442830","url":null,"abstract":"In environments that are remote and hazardous, tasks such as repairing and maintaining a robot manipulator can be extremely difficult and costly. Under such conditions, the operational reliability of a robotic system is very important and motivates the problem of designing optimally fault-tolerant manipulators. One solution to increasing the fault tolerance of a robotic system is to use kinematically redundant manipulators, as their extra degree of redundancy could be used to compensate for the failure in joint actuators. However, simply adding kinematic redundancy does not guarantee fault tolerance, rather it should be strategically added to ensure optimally fault-tolerant system. In this article the authors design nominal manipulator Jacobians that are optimally fault-tolerant to multiple joint failures. The special case when the manipulator is equally fault-tolerant to any two simultaneous joint failures is considered. While it is possible to design a six degree-of-freedom (DOF) robot manipulator to be equally fault-tolerant to any two simultaneous joint failures for three-dimensional workspaces, it is shown that no manipulator operating in a 4 or 5 dimensional workspace can be equally fault-tolerant to two failures.","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79688180","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 : 2010-03-07DOI: 10.1109/SSST.2010.5442839
Jiecai Luo, E. Walker, P. Bhattacharya, X. Chen
In this paper, geolocation problem using noisy differences in time of arrival (TDOA) and frequency difference of arrival (FDOA) measurements is considered, and a sub-BLUE solution is proposed, a new TDOA/FDOA based recursive geolocation algorithm is also developed. The efficiency of the new algorithms is illustrated with simulation results.
{"title":"A new TDOA/FDOA-based recursive geolocation algorithm","authors":"Jiecai Luo, E. Walker, P. Bhattacharya, X. Chen","doi":"10.1109/SSST.2010.5442839","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442839","url":null,"abstract":"In this paper, geolocation problem using noisy differences in time of arrival (TDOA) and frequency difference of arrival (FDOA) measurements is considered, and a sub-BLUE solution is proposed, a new TDOA/FDOA based recursive geolocation algorithm is also developed. The efficiency of the new algorithms is illustrated with simulation results.","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73056299","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 : 2010-03-07DOI: 10.1109/SSST.2010.5442850
C. Choi
State feedback using an observer is a technique for placing the poles of a linear system at desired locations. An application of such technique is to stabilize an unstable system by placing the new system poles in the left half plane. When the desired system poles are achieved by using observer state feedback, the step response parameters such as peak time, settling time, and percent overshoot are no longer controlled by the desired dominant system poles. The observer poles can change these parameters. This paper intends to elucidate this effect through computer simulations. A set of experiments were conducted with observer poles gradually farther away from the desired system poles. With the observer poles being pushed deeper into the left half plane, the observer states can track the system state faster. It is expected that the step response parameters will be closer to those dictated by the dominant poles. But such improvement was only minimally observed in the simulation results.
{"title":"Effect of observer poles on step responses","authors":"C. Choi","doi":"10.1109/SSST.2010.5442850","DOIUrl":"https://doi.org/10.1109/SSST.2010.5442850","url":null,"abstract":"State feedback using an observer is a technique for placing the poles of a linear system at desired locations. An application of such technique is to stabilize an unstable system by placing the new system poles in the left half plane. When the desired system poles are achieved by using observer state feedback, the step response parameters such as peak time, settling time, and percent overshoot are no longer controlled by the desired dominant system poles. The observer poles can change these parameters. This paper intends to elucidate this effect through computer simulations. A set of experiments were conducted with observer poles gradually farther away from the desired system poles. With the observer poles being pushed deeper into the left half plane, the observer states can track the system state faster. It is expected that the step response parameters will be closer to those dictated by the dominant poles. But such improvement was only minimally observed in the simulation results.","PeriodicalId":6463,"journal":{"name":"2010 42nd Southeastern Symposium on System Theory (SSST)","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2010-03-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75014166","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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