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2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.最新文献

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Scalability study of the CADV (congestion aware distance vector) routing protocol in mobile ad-hoc networks 移动自组织网络中CADV(拥塞感知距离矢量)路由协议的可扩展性研究
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458509
B. Tripathi, P. Agrawal, V. Khare, G. Rama Murthy
{"title":"Scalability study of the CADV (congestion aware distance vector) routing protocol in mobile ad-hoc networks","authors":"B. Tripathi, P. Agrawal, V. Khare, G. Rama Murthy","doi":"10.1109/SPCOM.2004.1458509","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458509","url":null,"abstract":"Mobile networking has established itself as the operational backbone of day-to-day human activities. Wireless devices are now more prevalent than ever before, and the existing systems are being inevitably subjected to scaling. But the existing routing protocols suffer scalability problems to varying extents. This paper examines the scalability issues pertinent to CADV protocol. The performance of the protocol is measured against select parameters. The behaviour of CADV is analyzed in a thickly populated network through detailed simulations. Based on the observations, conclusions are drawn on the scalability of CADV. The results provide us some valuable data, which can cater, not only to the operational concerns about CADV, but also to the needs of efficient, reliable and economical deployment, functioning and maintenance of the systems using it.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"225 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127950334","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}
引用次数: 1
Ambiguities of symmetrical linear arrays 对称线性阵列的模糊性
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458507
M. Agrawal, S. Prasad
{"title":"Ambiguities of symmetrical linear arrays","authors":"M. Agrawal, S. Prasad","doi":"10.1109/SPCOM.2004.1458507","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458507","url":null,"abstract":"In this letter, we build over earlier findings on the ambiguous behavior of the symmetrical linear arrays, which are used for the estimation of direction of arrival. These ambiguities arise due to the structure of the array and have direct impact on the uniqueness of the estimates. For a given array configuration, there may exist many such ambiguous sets of directions, which give non-unique estimates. We identify these ambiguous generator sets for a given symmetrical linear array. A new concept of ambiguous generator function is used to study the array ambiguities. The theoretical aspect of this investigation is followed by methods to calculate these ambiguous sets and is supported by a number of representative examples.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125641175","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}
引用次数: 0
Spectral estimation based on subband decomposition by harmonic wavelet transform and modified group delay 基于谐波小波变换和修正群延迟子带分解的频谱估计
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458416
S. Narasimhan, M. Harish
{"title":"Spectral estimation based on subband decomposition by harmonic wavelet transform and modified group delay","authors":"S. Narasimhan, M. Harish","doi":"10.1109/SPCOM.2004.1458416","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458416","url":null,"abstract":"A new spectral estimator that exploits the simplicity and computational efficiency of the harmonic wavelet transform (HWT) for signal decomposition and the variance reduction property of the modified group delay (MGD), without any loss in frequency resolution, has been proposed. As the HWT directly provides the decimated subband components in the frequency domain, it enables direct application of the MGD to subband signals. In the HWT, the decomposition separates different parts of the spectrum into subbands and the decimation stretches each subband spectrum, hence the frequency resolution improves. Further as this also separates a low level spectral peak from a strong neighboring one, the signal detectability also improves. The MGD improves noise immunity, as it not only removes the spectral ripples due to leakage effect but also due to the associated noise. In view of these, the new estimator facilitates a significant improvement in: the reduction of variance, frequency resolution and signal detectability; compared with those of the MGD processing of fullband signals.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131364345","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}
引用次数: 7
Wavelet based adaptive block parallel vector error diffusion for colour image halftone 基于小波的彩色图像半色调自适应块平行矢量误差扩散
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458514
S. Mondal, A. De
{"title":"Wavelet based adaptive block parallel vector error diffusion for colour image halftone","authors":"S. Mondal, A. De","doi":"10.1109/SPCOM.2004.1458514","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458514","url":null,"abstract":"In this paper, a block parallel vector error diffusion method has been proposed and illustrated for fast error diffusion halftoning of colour images. To reduce the colour artifacts arising due to block processing, an adaptive block error diffusion filter has been used. The adaptive block error diffusion filter has been implemented using Kronecker matrix multiplication and normalized least mean square algorithm. The proposed adaptive block error diffusion filter takes care of the relations between the three colour planes. Better sharpness control and edge enhancement has been achieved with the aid of wavelet processing. The results of the block processing are provided and the possible scopes of trade-offs are discussed.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131014457","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}
引用次数: 0
Fast and efficient secured lossless coding of medical images-use of the lifting scheme 快速高效的医学图像安全无损编码-使用提升方案
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458378
S. Annadurai, P. Geetha
{"title":"Fast and efficient secured lossless coding of medical images-use of the lifting scheme","authors":"S. Annadurai, P. Geetha","doi":"10.1109/SPCOM.2004.1458378","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458378","url":null,"abstract":"Lossless compression schemes with secure transmission play a key role in telemedicine applications that helps in accurate diagnosis and research. Traditional cryptographic algorithms for data security are not fast enough to process vast amount of data. Hence a novel secured lossless compression approach proposed in this paper is based on reversible integer wavelet transform, EZW algorithm arithmetic coding and selective bit scrambling. The use of the lifting scheme allows to generate truly lossless integer-to-integer wavelet transforms. Images are compressed/decompressed by well-known EZW algorithm and arithmetic coding is used to improve the compression performance and also increases the security level. The proposed approach employs scrambling method, which is fast, simple to implement, and it provides security. Lossless compression ratios and distortion performance of this proposed methods are found to be better than other lossless techniques.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"75 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134206055","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}
引用次数: 1
Efficient representation of 2D contour using non-uniform sampling 使用非均匀采样的二维轮廓的有效表示
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458352
Vibhutesh Kumar Singh, N. Rajpal
{"title":"Efficient representation of 2D contour using non-uniform sampling","authors":"Vibhutesh Kumar Singh, N. Rajpal","doi":"10.1109/SPCOM.2004.1458352","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458352","url":null,"abstract":"This paper presents a method of representation of an image boundary using non-uniform sampling technique. The boundary can be reconstructed back by Lagrange's interpolation of the samples. The proposed method uses an iterative procedure, which starts with uniform samples of the boundary. Then these samples are reduced to minimum by split and merge technique, which leads to non-uniform sampling of the boundary. The split and merge technique optimizes the number of control points required to represent a curve, thus achieving high compression ratios. The image boundary contour is optimally sampled to 'n' number of intervals. Then the curve is generated using Lagrange's interpolation method that passes through these n+1 points. The curve regenerated through interpolation is then compared with the original contour by weighted distance transform method Tsang, PWM et al., (1994). If the error is less than the tolerable range, then we merge two sample points to make one point and if the error is more than the tolerable range, then a new sample is added in the middle of two samples. The process is repeated till we get optimum number of sample points to reconstruct the contour. Thus only those sample points are retained which are necessary for reconstruction.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133547156","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}
引用次数: 3
PCA-based human auditory filter bank for speech recognition 基于pca的人类听觉滤波器组用于语音识别
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458488
V. D. Minh, Sungyoung Lee
{"title":"PCA-based human auditory filter bank for speech recognition","authors":"V. D. Minh, Sungyoung Lee","doi":"10.1109/SPCOM.2004.1458488","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458488","url":null,"abstract":"Although Mel-frequency Cepstral Coefficients (MFCC) has been proven to perform very well under most conditions, some limited efforts have been made in optimizing the shape of the filters in the filter-bank. In addition, MFCC does not approximate the critical bandwidth of the human auditory system. This paper presents a new feature extraction approach that (1) decouples filter bandwidth from other filter bank parameters inspired by the critical bands of the human auditory system and (2) designs the shape of the filters in the filter-bank. In this new approach, determining filter bandwidth is based on the approximation of critical band equivalent rectangular and the filter-bank coefficients are data-driven obtained by applying the principal component analysis (PCA) on the FFT spectrum of the training data. Though the experiments, we proved the noise robustness of this approach and the better performance of recognition systems.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"14 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133988381","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}
引用次数: 15
Transmitter precoding for space time CDMA system in multiuser communication 多用户通信中空时CDMA系统的发射机预编码
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458382
P. Yadav, K. Vasudevan
{"title":"Transmitter precoding for space time CDMA system in multiuser communication","authors":"P. Yadav, K. Vasudevan","doi":"10.1109/SPCOM.2004.1458382","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458382","url":null,"abstract":"The desire to reduce complexity at mobile unit in cellular system has led to the investigation of signal processing techniques that move the complexity from the mobile unit to the base station. Transmitter precoding is one such technique and it represents a linear transformation of transmitted signals, such that mean squared error at all receivers is minimised. In this paper, we investigate the performance of transmitter precoding technique for the downlink of multiple input single output (MISO) DS CDMA system over fading channel. Our receivers are constrained to simple matched filters and complete channel information (CSI) at the transmitter is assumed. This is feasible under the time division duplex (TDD) mode of the 3G UMTS system where channel is assumed to be the same on uplink and downlink and can be estimated from the uplink at the base station. It is seen that transmitter precoding for MISO system offers reasonable advantage over single antenna system precoding along with transferring computational complexity to the base station from mobile station.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"34 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130998782","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}
引用次数: 0
Fast technique for moving shadow detection in image sequences 图像序列中快速移动阴影检测技术
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458421
P. Shastry, K. Ramakrishnan
{"title":"Fast technique for moving shadow detection in image sequences","authors":"P. Shastry, K. Ramakrishnan","doi":"10.1109/SPCOM.2004.1458421","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458421","url":null,"abstract":"Automatic video surveillance systems typically involve tasks of moving object detection, object tracking, event analysis and detection of abnormality. One of the key requirements of scene understanding is detection and removal of moving shadows. In the context of real time automatic surveillance systems, considering the various tasks to be performed, detection of moving shadows needs to be performed with minimal computational complexity. Many algorithms have been proposed in the literature that deals with moving shadow detection. The existing algorithms treat tracking of objects and shadow detection tasks in an isolated manner. In this paper we present a technique for shadow detection, which uses motion information from the tracking module and hence greatly reduces the computational complexity.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134057375","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}
引用次数: 2
Effect of packet scheduling and evaluation of fuzzy based priority scheduler on ad hoc network unicast communication 分组调度及模糊优先级调度对自组网单播通信的影响
2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04. Pub Date : 2004-12-11 DOI: 10.1109/SPCOM.2004.1458511
C. Gomathy, S. Shanmugavel
{"title":"Effect of packet scheduling and evaluation of fuzzy based priority scheduler on ad hoc network unicast communication","authors":"C. Gomathy, S. Shanmugavel","doi":"10.1109/SPCOM.2004.1458511","DOIUrl":"https://doi.org/10.1109/SPCOM.2004.1458511","url":null,"abstract":"In mobile ad-hoc network, the mobility of nodes and the error prone nature of the wireless medium pose many challenges and packet losses. Here, since the nodes are mobile, the network topology changes rapidly and unpredictably over time and produce different queuing behaviour. Hence, a scheduling algorithm to schedule the packets based on their respective priorities will improve the performance of the network. Typically, packet schedulers in ad hoc networks give priority to control packets over data packets and serve data packets in FIFO order. Here, we present an fuzzy based priority scheduler for mobile ad-hoc networks, to determine the priority of the packets using dynamic source routing (DSR), ad hoc on demand distance vector routing (AODV) and wireless routing protocol (WRP) as the underlying unicast routing protocols. We find that setting priorities among data packets decrease the end to end delay significantly. The performance of this scheduler is studied using GloMoSim and evaluated in terms of quantitative metrics such as packet delivery ratio, average end to end delay and throughput. It is found that the scheduler provides overall improvement in the performance of the system, when tested with different unicast routing protocols under different mobility conditions.","PeriodicalId":424981,"journal":{"name":"2004 International Conference on Signal Processing and Communications, 2004. SPCOM '04.","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2004-12-11","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134315416","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}
引用次数: 3
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