Pub Date : 2004-09-27DOI: 10.1109/SSST.2004.1295635
M. N. Nyan, F. Tay, K. Seah
In this paper, we propose a novel eigenvector-based signal identification algorithm for multi-dimensional signal identification. Signal patterns of 3-D accelerometer output concerning human activities are of low frequency, non-stationary and transient, and can also be termed dynamic or time-varying patterns of arbitrary length. Therefore, a matrix was formed by including features from each dimension of extracted signal pattern, and transformed eigenvectors associated with maximum eigenvalues were used as feature vectors in the identification process. Eigenvectors can preserve the identification efficiency of the feature matrix and can have the smallest number of features for robust, reliable classification in the application of multidimensional analysis.
{"title":"Signal identification based on an eigenvector approach","authors":"M. N. Nyan, F. Tay, K. Seah","doi":"10.1109/SSST.2004.1295635","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295635","url":null,"abstract":"In this paper, we propose a novel eigenvector-based signal identification algorithm for multi-dimensional signal identification. Signal patterns of 3-D accelerometer output concerning human activities are of low frequency, non-stationary and transient, and can also be termed dynamic or time-varying patterns of arbitrary length. Therefore, a matrix was formed by including features from each dimension of extracted signal pattern, and transformed eigenvectors associated with maximum eigenvalues were used as feature vectors in the identification process. Eigenvectors can preserve the identification efficiency of the feature matrix and can have the smallest number of features for robust, reliable classification in the application of multidimensional analysis.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126292963","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 : 2004-09-27DOI: 10.1109/SSST.2004.1295722
R. Stephens
Reuse continues to be an important topic in most IT organizations. In a previous article, the author (2003) identifies the top obstacles in enterprise reuse as: lack of awareness of software available for reuse (repository), level of effort required to design software for reuse (education and lessons learned) and programmer lack of intent to actually reuse other organizational assets (education and executive support). This paper reviews a methodology utilized in a large telecommunications organization to measure reuse at the enterprise level. The paper reviews the different type of assets available for reuse, repository methodology, and specific metrics of reuse.
{"title":"Measuring enterprise reuse in large corporate environment","authors":"R. Stephens","doi":"10.1109/SSST.2004.1295722","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295722","url":null,"abstract":"Reuse continues to be an important topic in most IT organizations. In a previous article, the author (2003) identifies the top obstacles in enterprise reuse as: lack of awareness of software available for reuse (repository), level of effort required to design software for reuse (education and lessons learned) and programmer lack of intent to actually reuse other organizational assets (education and executive support). This paper reviews a methodology utilized in a large telecommunications organization to measure reuse at the enterprise level. The paper reviews the different type of assets available for reuse, repository methodology, and specific metrics of reuse.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126346767","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 : 2004-09-27DOI: 10.1109/SSST.2004.1295654
S. Balasubramanian, N. Thanthry, R. Bhagavathula, R. Pendse
As wired and wireless networks grow, underlying protocols need to be evaluated so that heterogeneous networks can be linked in an efficient manner. Among the transport layer protocols, user datagram protocol UDP is the only protocol that offers a fast and efficient mechanism to handle voice and video data traffic because it is a message based, connectionless service operating on the IP layer. In addition to the network conditions, it is observed that the performance also depends upon the implementation of the protocol. UNIX is one of the most widely used operating system in the networking world and different UNIX flavors have different UDP stack implementation. In this research work the performance of different UDP implementations were compared under different network conditions. It is observed that no UDP implementation dominates in all the tested network conditions. It is also observed that the selection of an appropriate datagram size had large impact on the overall performance.
{"title":"Performance analysis of UNIX user datagram protocol implementations","authors":"S. Balasubramanian, N. Thanthry, R. Bhagavathula, R. Pendse","doi":"10.1109/SSST.2004.1295654","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295654","url":null,"abstract":"As wired and wireless networks grow, underlying protocols need to be evaluated so that heterogeneous networks can be linked in an efficient manner. Among the transport layer protocols, user datagram protocol UDP is the only protocol that offers a fast and efficient mechanism to handle voice and video data traffic because it is a message based, connectionless service operating on the IP layer. In addition to the network conditions, it is observed that the performance also depends upon the implementation of the protocol. UNIX is one of the most widely used operating system in the networking world and different UNIX flavors have different UDP stack implementation. In this research work the performance of different UDP implementations were compared under different network conditions. It is observed that no UDP implementation dominates in all the tested network conditions. It is also observed that the selection of an appropriate datagram size had large impact on the overall performance.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"78 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114343549","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 : 2004-09-27DOI: 10.1109/SSST.2004.1295636
M. Shukla, A. Sekar
This paper proposes a new approach to examine the voltage security of the system. An approximate linear model that comprehensively includes the line flows and bus voltages in its formulation is the basis for analysis. Linear programming (LP) approach is used to calculate the load scenarios, which ensures the system security. Forecast of load scenarios that lead to system security is also possible. The linear programming is implemented using Excel spreadsheet [Microsoft EXCEL 2002]. The new methodology is implemented on a 5 bus system and the voltage profile is assessed. The results are verified by a power flow algorithm [ETAP Power Station 3.0]. The methodology is also implemented on the 14-bus IEEE system.
{"title":"Steady security assessment using linear programming methodology","authors":"M. Shukla, A. Sekar","doi":"10.1109/SSST.2004.1295636","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295636","url":null,"abstract":"This paper proposes a new approach to examine the voltage security of the system. An approximate linear model that comprehensively includes the line flows and bus voltages in its formulation is the basis for analysis. Linear programming (LP) approach is used to calculate the load scenarios, which ensures the system security. Forecast of load scenarios that lead to system security is also possible. The linear programming is implemented using Excel spreadsheet [Microsoft EXCEL 2002]. The new methodology is implemented on a 5 bus system and the voltage profile is assessed. The results are verified by a power flow algorithm [ETAP Power Station 3.0]. The methodology is also implemented on the 14-bus IEEE system.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127042680","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 : 2004-09-27DOI: 10.1109/SSST.2004.1295673
D. Wiegandt, C. Nassar, Z. Wu
Orthogonal frequency division multiplexing (OFDM) demonstrates symbol-by-symbol fluctuations in peak-to-average power ratio (PAPR), a direct consequence of independently modulated carriers. This, in turn, leads to inefficient operation of the transmit power amplifier, and/or in-band and out-of-band distortion due to power amplifier saturation. This paper extends our previous work, which explains how carrier interferometry (CI) spreading codes may be applied to OFDM (creating CI/OFDM) to eliminate PAPR fluctuations. Specifically, we analyze the PAPR benefits of CI codes in higher-order constellation OFDM systems (QPSK, 16-QAM, and 64-QAM OFDM). This work confirms that the proposed technique (of spreading the data symbols onto all carriers) ensures the elimination of high peaks in the signal envelope (thereby eliminating the PAPR problem): It is further shown that the choice of constellation size does little to change the PAPR benefits of the CI spreading technique.
{"title":"The elimination of peak-to-average power ratio concerns in OFDM via carrier interferometry spreading codes: a multiple constellation analysis","authors":"D. Wiegandt, C. Nassar, Z. Wu","doi":"10.1109/SSST.2004.1295673","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295673","url":null,"abstract":"Orthogonal frequency division multiplexing (OFDM) demonstrates symbol-by-symbol fluctuations in peak-to-average power ratio (PAPR), a direct consequence of independently modulated carriers. This, in turn, leads to inefficient operation of the transmit power amplifier, and/or in-band and out-of-band distortion due to power amplifier saturation. This paper extends our previous work, which explains how carrier interferometry (CI) spreading codes may be applied to OFDM (creating CI/OFDM) to eliminate PAPR fluctuations. Specifically, we analyze the PAPR benefits of CI codes in higher-order constellation OFDM systems (QPSK, 16-QAM, and 64-QAM OFDM). This work confirms that the proposed technique (of spreading the data symbols onto all carriers) ensures the elimination of high peaks in the signal envelope (thereby eliminating the PAPR problem): It is further shown that the choice of constellation size does little to change the PAPR benefits of the CI spreading technique.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126838984","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 : 2004-09-27DOI: 10.1109/SSST.2004.1295716
Ramin Amirifar, EE NasserSadati
An application of a continuous-time H/sub /spl infin// control to a flexible transmission system is presented. This approach has been proposed in order to assure high control performance in the presence of large load variation on the system. In this approach, the loading variations are considered as the multiplicative perturbation of the nominal plant. The desired specifications are enforced in the H/sub /spl infin// problem as the constraints on weighting functions. To obtain the desired performances, after an initial design procedure, the parameters of weighting functions are tuned and the final weighting functions are derived. The simulation results for three different loadings are given and compared.
{"title":"H/sub /spl infin// control of a flexible transmission system","authors":"Ramin Amirifar, EE NasserSadati","doi":"10.1109/SSST.2004.1295716","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295716","url":null,"abstract":"An application of a continuous-time H/sub /spl infin// control to a flexible transmission system is presented. This approach has been proposed in order to assure high control performance in the presence of large load variation on the system. In this approach, the loading variations are considered as the multiplicative perturbation of the nominal plant. The desired specifications are enforced in the H/sub /spl infin// problem as the constraints on weighting functions. To obtain the desired performances, after an initial design procedure, the parameters of weighting functions are tuned and the final weighting functions are derived. The simulation results for three different loadings are given and compared.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133757747","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 : 2004-09-27DOI: 10.1109/SSST.2004.1295682
C. Bishop
Over the past two decades, industry has come to depend heavily on models throughout the life cycle of a product. Government and industry organizations base major decisions about safety, product reliability, economic return, and environmental impact on model-based information. This paper focuses on the role of modeling throughout the life cycle of a product and addresses the unique characteristics required of models at each stage of the product life cycle, including: determination of user need, definition of product requirements, product development and testing, production and distribution, use, maintenance, and disposal.
{"title":"How a scientific theory of modeling can benefit industry","authors":"C. Bishop","doi":"10.1109/SSST.2004.1295682","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295682","url":null,"abstract":"Over the past two decades, industry has come to depend heavily on models throughout the life cycle of a product. Government and industry organizations base major decisions about safety, product reliability, economic return, and environmental impact on model-based information. This paper focuses on the role of modeling throughout the life cycle of a product and addresses the unique characteristics required of models at each stage of the product life cycle, including: determination of user need, definition of product requirements, product development and testing, production and distribution, use, maintenance, and disposal.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"80 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134628291","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 : 2004-09-27DOI: 10.1109/SSST.2004.1295644
Erik I. Verriest
The notion of balancing for linear systems is extended to the nonlinear realm. The proposed method of balancing is based upon three principles: 1) balancing should be defined with respect to a nominal flow; 2) only Gramians defined over small time intervals should be used to preserve the accuracy of the linear perturbation model and; 3) linearization should commute with balancing, in the sense that the linearization of a globally balanced model should correspond to the balanced linearized model in the original coordinates. Whereas it is generically possible to define a balanced framework locally, it is not possible to do so globally. Obstruction to the integrability of the Jacobian is generic in dimensions, n > 2. Here we show how to obtain the global balanced realization if the Mayer-Lie conditions are satisfied, and an interpolation method by integrable functions is proposed when this is not the case. The latter thus defines pseudo-balanced realizations.
{"title":"Nonlinear balancing and Mayer-Lie interpolation","authors":"Erik I. Verriest","doi":"10.1109/SSST.2004.1295644","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295644","url":null,"abstract":"The notion of balancing for linear systems is extended to the nonlinear realm. The proposed method of balancing is based upon three principles: 1) balancing should be defined with respect to a nominal flow; 2) only Gramians defined over small time intervals should be used to preserve the accuracy of the linear perturbation model and; 3) linearization should commute with balancing, in the sense that the linearization of a globally balanced model should correspond to the balanced linearized model in the original coordinates. Whereas it is generically possible to define a balanced framework locally, it is not possible to do so globally. Obstruction to the integrability of the Jacobian is generic in dimensions, n > 2. Here we show how to obtain the global balanced realization if the Mayer-Lie conditions are satisfied, and an interpolation method by integrable functions is proposed when this is not the case. The latter thus defines pseudo-balanced realizations.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130853860","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 : 2004-09-27DOI: 10.1109/SSST.2004.1295689
Hong Zhang, W. Gray, O. González
Single event upsets in digital flight control hardware induced by atmospheric neutrons can reduce system performance and possibly introduce a safety hazard. One method currently under investigation to help mitigate the effects of these upsets is NASA Langley's recoverable computer system. In this paper, a Markov jump-linear model is developed for a recoverable flight control system, which will be validated using data from future experiments with simulated and real neutron environments. The method of tracking error analysis and the plan for the experiments are also described.
{"title":"Markov jump-linear performance models for recoverable flight control computers","authors":"Hong Zhang, W. Gray, O. González","doi":"10.1109/SSST.2004.1295689","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295689","url":null,"abstract":"Single event upsets in digital flight control hardware induced by atmospheric neutrons can reduce system performance and possibly introduce a safety hazard. One method currently under investigation to help mitigate the effects of these upsets is NASA Langley's recoverable computer system. In this paper, a Markov jump-linear model is developed for a recoverable flight control system, which will be validated using data from future experiments with simulated and real neutron environments. The method of tracking error analysis and the plan for the experiments are also described.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"26 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133766721","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 : 2004-09-27DOI: 10.1109/SSST.2004.1295679
M. Hortman, D.G. Taylor
Presented in this paper is an extension to previous work on observer-based sensorless control of synchronous reluctance motors. The extensions include a systematic observer gain calculation that facilitates the use of gain scheduling to improve the transient response of the observer over a wide speed range and improve the low speed performance of the closed-loop sensorless controller. Laboratory experiments are used to demonstrate these improvements.
{"title":"Gain scheduled sensorless control of a synchronous reluctance motor","authors":"M. Hortman, D.G. Taylor","doi":"10.1109/SSST.2004.1295679","DOIUrl":"https://doi.org/10.1109/SSST.2004.1295679","url":null,"abstract":"Presented in this paper is an extension to previous work on observer-based sensorless control of synchronous reluctance motors. The extensions include a systematic observer gain calculation that facilitates the use of gain scheduling to improve the transient response of the observer over a wide speed range and improve the low speed performance of the closed-loop sensorless controller. Laboratory experiments are used to demonstrate these improvements.","PeriodicalId":309617,"journal":{"name":"Thirty-Sixth Southeastern Symposium on System Theory, 2004. Proceedings of the","volume":"69 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-09-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123883989","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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