Pub Date : 2003-10-15DOI: 10.1109/TENCON.2003.1273419
B. Singh, S. Murthy, S. Gupta
This paper presents an analysis of the three-phase self-excited induction generator (SEIG) with static-compensator (STATCOM) as a voltage regulator. Current controlled voltage source inverter (CC-VSI) is used as STATCOM, which provides fast dynamic response to maintain constant voltage at SEIG terminals during severe load perturbations and acts as a source and sink of reactive power. The performance equations are derived using d-q variable in stationary reference frame to develop a mathematical model of SEIG-STATCOM system feeding unbalanced loads. Transient analysis of the SEIG-STATCOM system is carried out for voltage build-up; switching in STATCOM, application and removal of balanced/unbalanced resistive/reactive loads. The STATCOM compensates the unbalanced load and keeps the generating system balanced while maintaining constant AC terminal voltage.
{"title":"Modelling and analysis of STATCOM based voltage regulator for self-excited induction generator with unbalanced loads","authors":"B. Singh, S. Murthy, S. Gupta","doi":"10.1109/TENCON.2003.1273419","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273419","url":null,"abstract":"This paper presents an analysis of the three-phase self-excited induction generator (SEIG) with static-compensator (STATCOM) as a voltage regulator. Current controlled voltage source inverter (CC-VSI) is used as STATCOM, which provides fast dynamic response to maintain constant voltage at SEIG terminals during severe load perturbations and acts as a source and sink of reactive power. The performance equations are derived using d-q variable in stationary reference frame to develop a mathematical model of SEIG-STATCOM system feeding unbalanced loads. Transient analysis of the SEIG-STATCOM system is carried out for voltage build-up; switching in STATCOM, application and removal of balanced/unbalanced resistive/reactive loads. The STATCOM compensates the unbalanced load and keeps the generating system balanced while maintaining constant AC terminal voltage.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"257 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126051456","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273436
S. Narasimhan, M. Harish
This paper proposes a new spectral estimator based on discrete cosine transform (DCT) and modified group delay function (MGD) (DCTMGD). The new estimator provides a significant reduction in variance and bias, better signal detection ability and frequency resolution compared with those of based on DFT (DFTMGD). The DCT provides reduced bias and hence enables good signal detection ability. The MGD enables better variance reduction without any loss in frequency resolution. For two sinusoids in noise, it has an improvement in variance of about 63% for SNR= 20 dB and 57% for SNR=0 dB, over those of DFTMGD. For the clean autoregressive (AR) process, the root mean square error (RMSE) reduces by 35% over that of DFTMGD. Further it is able to detect a sinusoid which is about 25 dB below AR spectral peaks.
{"title":"A new spectral estimator based on discrete cosine transform and modified group delay","authors":"S. Narasimhan, M. Harish","doi":"10.1109/TENCON.2003.1273436","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273436","url":null,"abstract":"This paper proposes a new spectral estimator based on discrete cosine transform (DCT) and modified group delay function (MGD) (DCTMGD). The new estimator provides a significant reduction in variance and bias, better signal detection ability and frequency resolution compared with those of based on DFT (DFTMGD). The DCT provides reduced bias and hence enables good signal detection ability. The MGD enables better variance reduction without any loss in frequency resolution. For two sinusoids in noise, it has an improvement in variance of about 63% for SNR= 20 dB and 57% for SNR=0 dB, over those of DFTMGD. For the clean autoregressive (AR) process, the root mean square error (RMSE) reduces by 35% over that of DFTMGD. Further it is able to detect a sinusoid which is about 25 dB below AR spectral peaks.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127784584","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273191
N. Sriraam, C. Eswaran
In this paper, the performance of different types of perceptron predictors for EEG signal compression is investigated. A two-stage lossless compression scheme which involves the decorrelation of EEG samples in the first stage and entropy coding in the second stage is considered. The second stage employs an arithmetic coding scheme. A comparison of the performance of the perceptron predictors with that of linear predictors such as FIR, NLMS is presented. It is found that the single-layer perceptron performs, in general, better than the multi-layer perceptrons as well as linear predictors.
{"title":"Performance of perceptron predictors for lossless EEG signal compression","authors":"N. Sriraam, C. Eswaran","doi":"10.1109/TENCON.2003.1273191","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273191","url":null,"abstract":"In this paper, the performance of different types of perceptron predictors for EEG signal compression is investigated. A two-stage lossless compression scheme which involves the decorrelation of EEG samples in the first stage and entropy coding in the second stage is considered. The second stage employs an arithmetic coding scheme. A comparison of the performance of the perceptron predictors with that of linear predictors such as FIR, NLMS is presented. It is found that the single-layer perceptron performs, in general, better than the multi-layer perceptrons as well as linear predictors.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127654528","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273377
A. Tiwari, R. R. Raja Kumar
In this paper, an improved lattice filter structure is presented to model a two-dimensional (2-D) signal such as an image. The proposed structure generates a forward and a backward prediction error field at each stage of lattice structure, unlike other lattice structures [S.R. Parker et al., 1984][N. Tulu Onuk et al., 1994] wherein three or more backward prediction error fields are generated at each stage. This method is computationally efficient and possesses all the advantages of lattice algorithm. Simulation results show that the proposed lattice method results in better compression with lower computational cost than other lattice methods in literature [H.K. Kwan et al., 2001].
本文提出了一种改进的点阵滤波器结构，用于对二维信号(如图像)进行建模。与其他晶格结构不同，本文提出的结构在晶格结构的每个阶段都会产生一个正向和向后的预测误差场[j]。Tulu Onuk et al.， 1994]，其中每个阶段产生三个或三个以上的后向预测误差场。该方法计算效率高，具有格算法的所有优点。仿真结果表明，本文提出的点阵方法比文献中的其他点阵方法具有更好的压缩效果和更低的计算成本Kwan等人，2001]。
{"title":"A lattice algorithm for lossless image compression using half-plane support data","authors":"A. Tiwari, R. R. Raja Kumar","doi":"10.1109/TENCON.2003.1273377","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273377","url":null,"abstract":"In this paper, an improved lattice filter structure is presented to model a two-dimensional (2-D) signal such as an image. The proposed structure generates a forward and a backward prediction error field at each stage of lattice structure, unlike other lattice structures [S.R. Parker et al., 1984][N. Tulu Onuk et al., 1994] wherein three or more backward prediction error fields are generated at each stage. This method is computationally efficient and possesses all the advantages of lattice algorithm. Simulation results show that the proposed lattice method results in better compression with lower computational cost than other lattice methods in literature [H.K. Kwan et al., 2001].","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"3 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129052990","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273319
T. Ravichandran, M. R. Reddy, A. Avudainayagam
Investigation of heart rate variability (HRV) has been the subject of considerable interest in the management of cardiac arrhythmia. Digital signal processing using instantaneous frequency and multiresolution analysis (Daubechies (db4) wavelet transforms) has been applied to estimate HRV without R point detection. The proposed method requires less memory for long term analysis as the ECG was measured with only 4 Hz sampling. Such a saving in memory makes it especially convenient to apply for long term analysis. The analysis of HRV using wavelet transforms was found to be very effective over conventional IIR filters. The sensitivity of the LF/HF ratio parameter increases with the Daubeches (db) based wavelet filter.
{"title":"Estimation and power spectral analysis of heart instantaneous frequency (HIF) - a wavelet approach","authors":"T. Ravichandran, M. R. Reddy, A. Avudainayagam","doi":"10.1109/TENCON.2003.1273319","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273319","url":null,"abstract":"Investigation of heart rate variability (HRV) has been the subject of considerable interest in the management of cardiac arrhythmia. Digital signal processing using instantaneous frequency and multiresolution analysis (Daubechies (db4) wavelet transforms) has been applied to estimate HRV without R point detection. The proposed method requires less memory for long term analysis as the ECG was measured with only 4 Hz sampling. Such a saving in memory makes it especially convenient to apply for long term analysis. The analysis of HRV using wavelet transforms was found to be very effective over conventional IIR filters. The sensitivity of the LF/HF ratio parameter increases with the Daubeches (db) based wavelet filter.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122226128","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273407
L. Siek, P. Chan, C.H. Yip, L. Chen
Conventional analog-to-digital (A/D) structure such as flash converter has a ladder of fixed reference voltages and massive number of comparators that grow exponentially with resolution. This paper presents a dynamic reference A/D converter, which requires the same number of comparators as the intended A/D bit resolutions. In addition, the dynamic reference A/D converter has built-in simple digital-to-analog (D/A) converter implementation in the feedforward path to establish the reference voltage dynamically. Furthermore, the conversion time for this technique is limited only by the propagation time of its internal signals. Therefore, the A/D converter can operate up to the maximum speed permitted by a given technology.
{"title":"A dynamic reference A/D converter","authors":"L. Siek, P. Chan, C.H. Yip, L. Chen","doi":"10.1109/TENCON.2003.1273407","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273407","url":null,"abstract":"Conventional analog-to-digital (A/D) structure such as flash converter has a ladder of fixed reference voltages and massive number of comparators that grow exponentially with resolution. This paper presents a dynamic reference A/D converter, which requires the same number of comparators as the intended A/D bit resolutions. In addition, the dynamic reference A/D converter has built-in simple digital-to-analog (D/A) converter implementation in the feedforward path to establish the reference voltage dynamically. Furthermore, the conversion time for this technique is limited only by the propagation time of its internal signals. Therefore, the A/D converter can operate up to the maximum speed permitted by a given technology.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"40 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130459622","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273285
A.G. Bhutad, S. V. Kulkarni, S. Khaparde
A distribution system has certain distinguishing features which make it different and somewhat difficult to analyze as compared to a transmission system. Unbalanced loads, untransposed lines, single-phase and two-phase laterals are some of them. The distribution system needs to be analyzed on the three-phase basis instead of the single-phase basis. Hence, the three-phase load flow for the distribution system is significantly different from the conventional load flow for the transmission system. In this paper, various load flow methods for distribution systems are reviewed. These methods are applied on a sample 8-bus system. The results are reported. The performance of these methods is compared for various parameters.
{"title":"Three-phase load flow methods for radial distribution networks","authors":"A.G. Bhutad, S. V. Kulkarni, S. Khaparde","doi":"10.1109/TENCON.2003.1273285","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273285","url":null,"abstract":"A distribution system has certain distinguishing features which make it different and somewhat difficult to analyze as compared to a transmission system. Unbalanced loads, untransposed lines, single-phase and two-phase laterals are some of them. The distribution system needs to be analyzed on the three-phase basis instead of the single-phase basis. Hence, the three-phase load flow for the distribution system is significantly different from the conventional load flow for the transmission system. In this paper, various load flow methods for distribution systems are reviewed. These methods are applied on a sample 8-bus system. The results are reported. The performance of these methods is compared for various parameters.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"21 8","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131540143","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273321
M. Sutaone, P. Bartakke, V. Vyas, N. B. Pasalkar
This paper deals with texture feature extraction operators, which comprise linear filtering eventually followed by post processing. Robust, rotation and scale invariant texture operators are important for digital image libraries and multimedia databases. A method of rotation and scale-invariant texture classification based on a log polar coordinate system is introduced. Texture is an important clue in region based segmentation of images. Here, we provide analysis and implementation of a set of distortion invariant texture operators viz circular Mellin features (CMF). The CMF represent the spectral decomposition of the image scene in the polar log coordinate system and are invariant to both scale and orientation of the target texture pattern. The image and CMF are correlated followed by magnitude detection based on thresholding. The CMF extractors have a functional form that is similar to Gabor functions; they have distortion invariant characteristics, unlike Gabor functions, which makes them more suitable for texture segmentation.
{"title":"Rotation and scale invariant feature extractors","authors":"M. Sutaone, P. Bartakke, V. Vyas, N. B. Pasalkar","doi":"10.1109/TENCON.2003.1273321","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273321","url":null,"abstract":"This paper deals with texture feature extraction operators, which comprise linear filtering eventually followed by post processing. Robust, rotation and scale invariant texture operators are important for digital image libraries and multimedia databases. A method of rotation and scale-invariant texture classification based on a log polar coordinate system is introduced. Texture is an important clue in region based segmentation of images. Here, we provide analysis and implementation of a set of distortion invariant texture operators viz circular Mellin features (CMF). The CMF represent the spectral decomposition of the image scene in the polar log coordinate system and are invariant to both scale and orientation of the target texture pattern. The image and CMF are correlated followed by magnitude detection based on thresholding. The CMF extractors have a functional form that is similar to Gabor functions; they have distortion invariant characteristics, unlike Gabor functions, which makes them more suitable for texture segmentation.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"54 10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"132713207","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273204
S. Kulkarni, Vimlesh Kumar, B. N. Chatterji
We propose here an efficient geometric active contouring method based on the level set approach for extracting objects from natural images described in vector-valued form. Natural images are characterized by absence of global minima for mean squared error, an energy minimization formulation based on the the principles of the calculus of variations, that helps in effective segmentation based on boundary information. The approach adopted is to treat this segmentation as a minimum partition approximation problem, using additional regularization terms. The constraints for stopping the evolving curve are derived by coupling information from each of the vectors of the vector described image. The coupling effect from each vector increases the segmentation accuracy. The results are qualitatively compared with an existing Chan et al. (1999) model and are found to be much superior.
本文提出了一种基于水平集的高效几何主动轮廓方法，用于从向量值形式描述的自然图像中提取目标。自然图像的特点是缺乏均方误差的全局最小值，这是一种基于变分原理的能量最小化公式，有助于基于边界信息的有效分割。采用的方法是使用额外的正则化项将此分割视为最小分割近似问题。通过从矢量描述图像的每个矢量中耦合信息，推导出停止曲线演化的约束条件。每个向量的耦合效应提高了分割精度。结果与现有的Chan et al.(1999)模型进行了定性比较，发现要优越得多。
{"title":"Edgeless active contouring, for vector-valued natural image segmentation","authors":"S. Kulkarni, Vimlesh Kumar, B. N. Chatterji","doi":"10.1109/TENCON.2003.1273204","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273204","url":null,"abstract":"We propose here an efficient geometric active contouring method based on the level set approach for extracting objects from natural images described in vector-valued form. Natural images are characterized by absence of global minima for mean squared error, an energy minimization formulation based on the the principles of the calculus of variations, that helps in effective segmentation based on boundary information. The approach adopted is to treat this segmentation as a minimum partition approximation problem, using additional regularization terms. The constraints for stopping the evolving curve are derived by coupling information from each of the vectors of the vector described image. The coupling effect from each vector increases the segmentation accuracy. The results are qualitatively compared with an existing Chan et al. (1999) model and are found to be much superior.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"25 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128174414","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 : 2003-10-15DOI: 10.1109/TENCON.2003.1273288
V.B.B.M. Thara
Turbo codes are part of the standardization for the 3G wireless communication system. They have been chosen for their error correcting ability to approach the Shannon limit. In a standard turbo coding system, all bits are transmitted with equal energy. This strategy does not guarantee optimum allocation. UPA ( unequal power allocation) been adopted to optimize the power allocation for each bit stream. Using new modified technique for UPA, the performance of turbo codes is studied.
{"title":"New UPA scheme for turbo codes in cdma2000 system","authors":"V.B.B.M. Thara","doi":"10.1109/TENCON.2003.1273288","DOIUrl":"https://doi.org/10.1109/TENCON.2003.1273288","url":null,"abstract":"Turbo codes are part of the standardization for the 3G wireless communication system. They have been chosen for their error correcting ability to approach the Shannon limit. In a standard turbo coding system, all bits are transmitted with equal energy. This strategy does not guarantee optimum allocation. UPA ( unequal power allocation) been adopted to optimize the power allocation for each bit stream. Using new modified technique for UPA, the performance of turbo codes is studied.","PeriodicalId":405847,"journal":{"name":"TENCON 2003. Conference on Convergent Technologies for Asia-Pacific Region","volume":"27 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2003-10-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128340751","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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