Pub Date : 2007-11-24DOI: 10.1109/ICSPC.2007.4728342
Victoria Sgardoni, P. Ferré, A. Doufexi, Andrew R. Nix, David R. Bull
This paper presents simulation results for the transmission of unicast MAC frames over 802.11a/g. Fading channel models at various Doppler spreads are developed to generate time-correlated SNR waveforms. These are used in a bit accurate MAC/PHY simulator to estimate frame loss rate, transmission delay, jitter and throughput for a steady flow of transmit frames. Time-correlated channels are required to correctly simulate the bursty nature of packet loss in a wireless channel. The Doppler spread is shown to have a strong effect on the performance of 802.11 ARQ at the MAC layer. Compared to the slow fading case, in a fast fading channel fewer MAC layer retransmissions are required and the end-to-end delay is significantly reduced. Under poor channel conditions the simulated delay and frame loss rate are seriously underestimated if time-uncorrelated fading is assumed.
{"title":"Frame Delay, Loss Rate and Throughput Analysis for Video Applications over time correlated 802.11a/g channels","authors":"Victoria Sgardoni, P. Ferré, A. Doufexi, Andrew R. Nix, David R. Bull","doi":"10.1109/ICSPC.2007.4728342","DOIUrl":"https://doi.org/10.1109/ICSPC.2007.4728342","url":null,"abstract":"This paper presents simulation results for the transmission of unicast MAC frames over 802.11a/g. Fading channel models at various Doppler spreads are developed to generate time-correlated SNR waveforms. These are used in a bit accurate MAC/PHY simulator to estimate frame loss rate, transmission delay, jitter and throughput for a steady flow of transmit frames. Time-correlated channels are required to correctly simulate the bursty nature of packet loss in a wireless channel. The Doppler spread is shown to have a strong effect on the performance of 802.11 ARQ at the MAC layer. Compared to the slow fading case, in a fast fading channel fewer MAC layer retransmissions are required and the end-to-end delay is significantly reduced. Under poor channel conditions the simulated delay and frame loss rate are seriously underestimated if time-uncorrelated fading is assumed.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121419837","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 : 2007-11-24DOI: 10.1109/ICSPC.2007.4728363
M. Saadatmand-Tarzjan, H. Ghassemian
In this paper, a new active contour model called self-affine snake is proposed which integrates the self-affine mapping system (SAMS), wavelet transform, and snake model. It inherits wide capture range from the wavelet transform, both accurate fit to weak edges and effective reconstruction of boundary concavities from SAMS, and topological consistency from the snake model while avoiding their weak points. In self-affine snake, first, a force vector is computed for every pixel in each wavelet LL matrix using SAMS with disk domains. Then the obtained force fields of different wavelet scales are effectively combined to make the self-affine force filed. Finally, the snake is deformed using the resultant forces based on the snake dynamic formulation. Experiment results demonstrate good performance for self-affine snake compared to the balloon for a number of synthetic and biomedical benchmark images.
{"title":"Self-Affine Snake: A New Parametric Active Contour","authors":"M. Saadatmand-Tarzjan, H. Ghassemian","doi":"10.1109/ICSPC.2007.4728363","DOIUrl":"https://doi.org/10.1109/ICSPC.2007.4728363","url":null,"abstract":"In this paper, a new active contour model called self-affine snake is proposed which integrates the self-affine mapping system (SAMS), wavelet transform, and snake model. It inherits wide capture range from the wavelet transform, both accurate fit to weak edges and effective reconstruction of boundary concavities from SAMS, and topological consistency from the snake model while avoiding their weak points. In self-affine snake, first, a force vector is computed for every pixel in each wavelet LL matrix using SAMS with disk domains. Then the obtained force fields of different wavelet scales are effectively combined to make the self-affine force filed. Finally, the snake is deformed using the resultant forces based on the snake dynamic formulation. Experiment results demonstrate good performance for self-affine snake compared to the balloon for a number of synthetic and biomedical benchmark images.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125720629","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 : 2007-11-24DOI: 10.1109/ICSPC.2007.4728443
D. Fohr, I. Illina
In this paper we present an automated approach for text-independent foreign accent classification. Results of foreign accent classification task could be used for adapting acoustic models, modifying lexicon, changing language model with regards to non-native speakers. In our study, we investigate statistical approaches which differ from the a priori knowledge they need: GMM, which requires neither phonetic knowledge nor labelling, phone recognition (without a lexicon), sentence recognition (with a lexicon and a grammar). This work is done in the framework of the HIWIRE (Human Input that Works In Real Environment) European project. We evaluated the proposed approaches on English speech corpus pronounced by French, Italian and Greek speakers. All experiments were performed in speaker-independent and text-independent mode. The best classification rate (83.3%) is achieved using sentence recognition or a phone-based recognition followed by language modelling approach.
{"title":"Text-Independent Foreign Accent Classification using Statistical Methods","authors":"D. Fohr, I. Illina","doi":"10.1109/ICSPC.2007.4728443","DOIUrl":"https://doi.org/10.1109/ICSPC.2007.4728443","url":null,"abstract":"In this paper we present an automated approach for text-independent foreign accent classification. Results of foreign accent classification task could be used for adapting acoustic models, modifying lexicon, changing language model with regards to non-native speakers. In our study, we investigate statistical approaches which differ from the a priori knowledge they need: GMM, which requires neither phonetic knowledge nor labelling, phone recognition (without a lexicon), sentence recognition (with a lexicon and a grammar). This work is done in the framework of the HIWIRE (Human Input that Works In Real Environment) European project. We evaluated the proposed approaches on English speech corpus pronounced by French, Italian and Greek speakers. All experiments were performed in speaker-independent and text-independent mode. The best classification rate (83.3%) is achieved using sentence recognition or a phone-based recognition followed by language modelling approach.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130630803","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 : 2007-11-24DOI: 10.1109/ICSPC.2007.4728314
Lingchuan Zhou, M. Ayachi, J. Blonde, F. Braun
In this paper a new 0.35 μm CMOS technology second generation current conveyor (CCII) is presented. It is a low power (60 μA @ ± 1.5 V power supply) circuit, featuring 88 × 100 μm2 area, 100 MHz bandwidth and 10 GHz equivalent gain bandwidth (GBW) product. Its static and dynamic characteristics when used both as a voltage and current buffer are described. The chip has been fabricated and tested, and experimental results are discussed. Its use in an application as an instrumentation amplifier (IA) is also presented. The CCII based IA has weaker offset and better CMRR than its voltage mode equivalent. In order to cancel output offset voltage and reduce noise, the IA's input and output signals are chopped at high frequency.
{"title":"A 100 MHz Current Conveyor in 0.35 μm CMOS Technology","authors":"Lingchuan Zhou, M. Ayachi, J. Blonde, F. Braun","doi":"10.1109/ICSPC.2007.4728314","DOIUrl":"https://doi.org/10.1109/ICSPC.2007.4728314","url":null,"abstract":"In this paper a new 0.35 μm CMOS technology second generation current conveyor (CCII) is presented. It is a low power (60 μA @ ± 1.5 V power supply) circuit, featuring 88 × 100 μm2 area, 100 MHz bandwidth and 10 GHz equivalent gain bandwidth (GBW) product. Its static and dynamic characteristics when used both as a voltage and current buffer are described. The chip has been fabricated and tested, and experimental results are discussed. Its use in an application as an instrumentation amplifier (IA) is also presented. The CCII based IA has weaker offset and better CMRR than its voltage mode equivalent. In order to cancel output offset voltage and reduce noise, the IA's input and output signals are chopped at high frequency.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"77 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116446433","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 : 2007-11-24DOI: 10.1109/ICSPC.2007.4728470
S. Guizani, H. Hamam
Transmitting ultra wideband (UWB) pulse signals over optical fiber is a certain sign of chromatic dispersion (CD) existence. CD is a serious problem in optical transmission because the velocity of light depends on the frequencies. The effect is strengthened when the optical pulse gets shorter because its spectrum gets broader. This results in a temporal broadening of the initial pulse. The signal is then deformed during propagation, resulting in inter-symbol interference (ISI). Alteration is more pronounced if the optical signal travels further, yielding to shortening the inter-repeater distance. We propose a method for chromatic dispersion compensation. It is based on the temporal Talbot effect that is observed when a periodic signal propagates through a dispersive medium at a given distance named Talbot distance ZT. Our method consists in adding a portion of a dispersive fiber so that the overall propagation distance corresponds to one specific distance, called a fractional Talbot distance. Because a specific length of a generally long fiber is put into play, the tolerance permitted by the approach needs particular attention.
{"title":"Self-Imaging based Dispersion Compensation: Performance and Tolerance of the System","authors":"S. Guizani, H. Hamam","doi":"10.1109/ICSPC.2007.4728470","DOIUrl":"https://doi.org/10.1109/ICSPC.2007.4728470","url":null,"abstract":"Transmitting ultra wideband (UWB) pulse signals over optical fiber is a certain sign of chromatic dispersion (CD) existence. CD is a serious problem in optical transmission because the velocity of light depends on the frequencies. The effect is strengthened when the optical pulse gets shorter because its spectrum gets broader. This results in a temporal broadening of the initial pulse. The signal is then deformed during propagation, resulting in inter-symbol interference (ISI). Alteration is more pronounced if the optical signal travels further, yielding to shortening the inter-repeater distance. We propose a method for chromatic dispersion compensation. It is based on the temporal Talbot effect that is observed when a periodic signal propagates through a dispersive medium at a given distance named Talbot distance ZT. Our method consists in adding a portion of a dispersive fiber so that the overall propagation distance corresponds to one specific distance, called a fractional Talbot distance. Because a specific length of a generally long fiber is put into play, the tolerance permitted by the approach needs particular attention.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"51 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131001139","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 : 2007-11-24DOI: 10.1109/ICSPC.2007.4728460
U. Qidwai, M. Shamim, F. Raquib, A. Enam
In this paper a fuzzy inference system (FIS) is presented to predict the level of risk for a class of patients to be needing a repeated surgery for the herniated lumber disc (or more commonly known as slipped disc). The FIS is based upon a clinical study that was conducted by a number of doctors at Aga Khan University Hospital in Pakistan with the objective that certain clinical measures can be used from the beginning to assist the physician in making a better risk estimate for the patient at hand. As such, over 90 clinical markers were collected through patients' surveys over a period of 5 years (2000-2004). The presented study utilizes a subset of 16 markers and has recommendation for 7 of these markers for a reasonably accurate risk prediction. A set of 11 rules has been established that constitute the mapped understanding from the physicians' heuristics. Such a system will be a very helpful tool for medical professionals for making quick risk assessment for a patient and will enable them to more accurately define the treatment for the same.
{"title":"Failed Back Surgery Syndrome (FBSS) Prediction using Fuzzy Inference System (FIS)","authors":"U. Qidwai, M. Shamim, F. Raquib, A. Enam","doi":"10.1109/ICSPC.2007.4728460","DOIUrl":"https://doi.org/10.1109/ICSPC.2007.4728460","url":null,"abstract":"In this paper a fuzzy inference system (FIS) is presented to predict the level of risk for a class of patients to be needing a repeated surgery for the herniated lumber disc (or more commonly known as slipped disc). The FIS is based upon a clinical study that was conducted by a number of doctors at Aga Khan University Hospital in Pakistan with the objective that certain clinical measures can be used from the beginning to assist the physician in making a better risk estimate for the patient at hand. As such, over 90 clinical markers were collected through patients' surveys over a period of 5 years (2000-2004). The presented study utilizes a subset of 16 markers and has recommendation for 7 of these markers for a reasonably accurate risk prediction. A set of 11 rules has been established that constitute the mapped understanding from the physicians' heuristics. Such a system will be a very helpful tool for medical professionals for making quick risk assessment for a patient and will enable them to more accurately define the treatment for the same.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"10 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127477426","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 : 2007-11-24DOI: 10.1109/ICSPC.2007.4728417
M. N. Daikpor, O. Adegbenro
In this contribution we present radix-7 signed digit element finite fields as a gateway to multiple-value logic public key cryptographic systems design. We also construct signed digit Galois Field SGF(72). A radix-7 signed digit element finite field multiplication circuit is implemented using complementary pass-gate derived 7-value T-gate.
{"title":"Radix - 7 Signed Digit Element Finite Field Arithmetic","authors":"M. N. Daikpor, O. Adegbenro","doi":"10.1109/ICSPC.2007.4728417","DOIUrl":"https://doi.org/10.1109/ICSPC.2007.4728417","url":null,"abstract":"In this contribution we present radix-7 signed digit element finite fields as a gateway to multiple-value logic public key cryptographic systems design. We also construct signed digit Galois Field SGF(72). A radix-7 signed digit element finite field multiplication circuit is implemented using complementary pass-gate derived 7-value T-gate.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"8 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129616917","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 : 2007-11-24DOI: 10.1109/ISSPA.2007.4555603
U. Qidwai, M. Bettayeb, A. Yamani
Classification of defects using ultrasonic nondestructive testing (NDT) is primarily done in the field of industrial materials to provide useful information in order to assist in making administrative decisions in terms of maintenance and replacement. The technique presented in this paper utilizes the concept of defect induction as a convolution process between the clean sample and the defect signature. Hence, to identify the type of defect a deconvolution approach can be useful. Due to several similarities between the ultrasonic echoes and the usual modulated sinusoids, a motivation is present to use 4th order statistics for completely defining the waveform. Such a definition, when compared with standard defects, will provide useful insight in terms of defect classifications and understanding.
{"title":"Defect Deconvolution using 4th Order Statistics for Ultrasonic Nondestructive Testing","authors":"U. Qidwai, M. Bettayeb, A. Yamani","doi":"10.1109/ISSPA.2007.4555603","DOIUrl":"https://doi.org/10.1109/ISSPA.2007.4555603","url":null,"abstract":"Classification of defects using ultrasonic nondestructive testing (NDT) is primarily done in the field of industrial materials to provide useful information in order to assist in making administrative decisions in terms of maintenance and replacement. The technique presented in this paper utilizes the concept of defect induction as a convolution process between the clean sample and the defect signature. Hence, to identify the type of defect a deconvolution approach can be useful. Due to several similarities between the ultrasonic echoes and the usual modulated sinusoids, a motivation is present to use 4th order statistics for completely defining the waveform. Such a definition, when compared with standard defects, will provide useful insight in terms of defect classifications and understanding.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"18 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128977655","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 : 2007-11-24DOI: 10.1109/ICSPC.2007.4728617
D. Helbert, M. Khoudeir, M. Do
Within the framework of the analysis of 3D textured environment through image analysis, we approach here the case of the rough surfaces for the analysis of the local variations of their relief. Generally, the interaction between the light and these local relief variations leads to a textured image of these surfaces. The proposed approach is an original stereovision adaptation based on photometric model to the case of surfaces with a high degree of roughness and with Lambert's photometric behaviour. Indeed, the usual approach treats only the case of surfaces with weak roughness, without consideration of the phenomena such as interreflexions, shades or still maskings between elementary facets of surface. We propose to take into account these phenomena through the adaptation of Oren-Nayar's model for the photometric stereovision. A comparative study is done to put out the contribution of the proposed approach in the case of rough surfaces.
{"title":"Rough Surfaces and Relief Extraction by Generalized Lambertian's Photometric Model","authors":"D. Helbert, M. Khoudeir, M. Do","doi":"10.1109/ICSPC.2007.4728617","DOIUrl":"https://doi.org/10.1109/ICSPC.2007.4728617","url":null,"abstract":"Within the framework of the analysis of 3D textured environment through image analysis, we approach here the case of the rough surfaces for the analysis of the local variations of their relief. Generally, the interaction between the light and these local relief variations leads to a textured image of these surfaces. The proposed approach is an original stereovision adaptation based on photometric model to the case of surfaces with a high degree of roughness and with Lambert's photometric behaviour. Indeed, the usual approach treats only the case of surfaces with weak roughness, without consideration of the phenomena such as interreflexions, shades or still maskings between elementary facets of surface. We propose to take into account these phenomena through the adaptation of Oren-Nayar's model for the photometric stereovision. A comparative study is done to put out the contribution of the proposed approach in the case of rough surfaces.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"31 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115093664","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 : 2007-11-21DOI: 10.1109/ICSPC.2007.4728564
I. Sarris, A. Nix, A. Doufexi
In this paper the performance of a wireless architecture that enables ultra-broadband wireless transmission is presented. This architecture corresponds to a system with multiple antenna elements on the transmitter and the receiver (MIMO) employing a spatial multiplexing technique conforming to the 802.16 (WiMAX) standard. The physical layer performance of this system is assessed by means of MIMO measurements in a home environment. The results are presented and discussed in terms of the bit-error-rate (BER) for a standard and a novel LoS-optimised antenna array architecture.
{"title":"WiMAX MIMO Measurement in a Residential Line-of-Sight Environment","authors":"I. Sarris, A. Nix, A. Doufexi","doi":"10.1109/ICSPC.2007.4728564","DOIUrl":"https://doi.org/10.1109/ICSPC.2007.4728564","url":null,"abstract":"In this paper the performance of a wireless architecture that enables ultra-broadband wireless transmission is presented. This architecture corresponds to a system with multiple antenna elements on the transmitter and the receiver (MIMO) employing a spatial multiplexing technique conforming to the 802.16 (WiMAX) standard. The physical layer performance of this system is assessed by means of MIMO measurements in a home environment. The results are presented and discussed in terms of the bit-error-rate (BER) for a standard and a novel LoS-optimised antenna array architecture.","PeriodicalId":425397,"journal":{"name":"2007 IEEE International Conference on Signal Processing and Communications","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2007-11-21","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115781094","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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