Pub Date : 2009-05-04DOI: 10.1109/RADAR.2009.4977108
G. Crain, M. Yeary, C. Kidder, A. Zahrai, G. Zhang, R. Doviak, R. Palmer, T. Yu, M. Xue, Y. Zhang, Q. Xu, P. Chilson
The National Weather Radar Testbed (NWRT) system is based on WSR-88D technology enhanced with the significant capability of a Phased Array Antenna. The agile beam capability provides a unique and powerful tool to focus weather radar asset on observation of severe weather phenomena including structures that lead to formation of these storms. The NWRT system has demonstrated the ability to provide weather data consistent with that from adjacent WSR systems at greatly reduced volume coverage time. Significant success has been reported in use of this tool for gathering and presenting specific, real-time storm-cell 3-D data to weather scientists and meteorologists for in-depth interpretation of these pencil-beam radar returns. Specific extensions to the conventional weather radar capabilities now in place include Beam Multiplexing (spatial filtering), Oversampling and Whitening (signal processing) and Transverse Wind Estimation (multi-beam). The latter capability has recently been added by activating the difference beam channels of the array and sequentially sampling and comparing these with the conventional sum-only mode. Under the auspices of a National Science Foundation, Major Research Instrument (NSF/MRI) grant, and in cooperation with the United States Navy, the NWRT is now being extended with an 8-channel digital receiver for simultaneous processing of sum, difference and ancillary beam returns. Expectations are high that application of multi-beam adaptation algorithms and other signal processing techniques using multiple channels will lead to improved detection and storm queuing techniques to greatly extend the forecast lead time for severe storms. Multi-channel capability also opens the NWRT for the possibility of testing Multi-Function radar system algorithms and operations. This paper will describe the attributes of the COTS, rf-system extensions and the specific steps being taken to baseline these changes to the current NWRT system performance.
{"title":"Multi-channel conversion of the National Weather Radar Testbed receiver","authors":"G. Crain, M. Yeary, C. Kidder, A. Zahrai, G. Zhang, R. Doviak, R. Palmer, T. Yu, M. Xue, Y. Zhang, Q. Xu, P. Chilson","doi":"10.1109/RADAR.2009.4977108","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4977108","url":null,"abstract":"The National Weather Radar Testbed (NWRT) system is based on WSR-88D technology enhanced with the significant capability of a Phased Array Antenna. The agile beam capability provides a unique and powerful tool to focus weather radar asset on observation of severe weather phenomena including structures that lead to formation of these storms. The NWRT system has demonstrated the ability to provide weather data consistent with that from adjacent WSR systems at greatly reduced volume coverage time. Significant success has been reported in use of this tool for gathering and presenting specific, real-time storm-cell 3-D data to weather scientists and meteorologists for in-depth interpretation of these pencil-beam radar returns. Specific extensions to the conventional weather radar capabilities now in place include Beam Multiplexing (spatial filtering), Oversampling and Whitening (signal processing) and Transverse Wind Estimation (multi-beam). The latter capability has recently been added by activating the difference beam channels of the array and sequentially sampling and comparing these with the conventional sum-only mode. Under the auspices of a National Science Foundation, Major Research Instrument (NSF/MRI) grant, and in cooperation with the United States Navy, the NWRT is now being extended with an 8-channel digital receiver for simultaneous processing of sum, difference and ancillary beam returns. Expectations are high that application of multi-beam adaptation algorithms and other signal processing techniques using multiple channels will lead to improved detection and storm queuing techniques to greatly extend the forecast lead time for severe storms. Multi-channel capability also opens the NWRT for the possibility of testing Multi-Function radar system algorithms and operations. This paper will describe the attributes of the COTS, rf-system extensions and the specific steps being taken to baseline these changes to the current NWRT system performance.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"79 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133574561","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 : 2009-05-04DOI: 10.1109/RADAR.2009.4977102
Bo Li, Bin Xu, Yeshu Yuan
A modified array interpolation approach to correlated source localization is presented for the surface wave radar (SWR) that employs multiple uniform linear subarrays (ULSAs) mounted on different ships to compose a multistatic shipborne SWR receiving array. This approach that overcomes the main shortcomings of some existing interpolation techniques, comprises three stages: a first stage for preestimating direction-of-arrivals (DOAs) on an assumption that at least a single ULSA is available for correlated source localization, a second stage for specifying a union of nonoverlapping narrow subsectors as the interpolated sector to cover only the preestimates, and a third stage for reestimating DOAs with the virtual uniform linear array (VULA), in which we skip noise prewhitening and appropriately increase the amount of forward/backward spatial smoothing (FBSS) that plays a major role in lowering noise floor while decorrelating correlated sources. Monte Carlo simulations demonstrate the validity of our proposal.
{"title":"Enhanced DOA visibility of correlated sources for multistatic shipborne surface wave radar","authors":"Bo Li, Bin Xu, Yeshu Yuan","doi":"10.1109/RADAR.2009.4977102","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4977102","url":null,"abstract":"A modified array interpolation approach to correlated source localization is presented for the surface wave radar (SWR) that employs multiple uniform linear subarrays (ULSAs) mounted on different ships to compose a multistatic shipborne SWR receiving array. This approach that overcomes the main shortcomings of some existing interpolation techniques, comprises three stages: a first stage for preestimating direction-of-arrivals (DOAs) on an assumption that at least a single ULSA is available for correlated source localization, a second stage for specifying a union of nonoverlapping narrow subsectors as the interpolated sector to cover only the preestimates, and a third stage for reestimating DOAs with the virtual uniform linear array (VULA), in which we skip noise prewhitening and appropriately increase the amount of forward/backward spatial smoothing (FBSS) that plays a major role in lowering noise floor while decorrelating correlated sources. Monte Carlo simulations demonstrate the validity of our proposal.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"4 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"128064958","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 : 2009-05-04DOI: 10.1109/RADAR.2009.4976944
Xie Wei, Xiong Jian
A novel transmitting wide DBF algorithm based on time-domain filter is presented in this paper. The mature FIR filter was used to form transmitting wideband digital beam in time domain. The signal with continuous phase cannot be transmitted by frequency-domain algorithm. The right beam direction in non-reference frequency point couldn't get by adaptive filter algorithm. Many flaws in traditional method can be overcome by the method in this article. Finally, the practicability and validity of the proposed algorithm were proved by computer simulation.
{"title":"A transmitting wideband DBF algorithm based on time-domain filter","authors":"Xie Wei, Xiong Jian","doi":"10.1109/RADAR.2009.4976944","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4976944","url":null,"abstract":"A novel transmitting wide DBF algorithm based on time-domain filter is presented in this paper. The mature FIR filter was used to form transmitting wideband digital beam in time domain. The signal with continuous phase cannot be transmitted by frequency-domain algorithm. The right beam direction in non-reference frequency point couldn't get by adaptive filter algorithm. Many flaws in traditional method can be overcome by the method in this article. Finally, the practicability and validity of the proposed algorithm were proved by computer simulation.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133457375","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 : 2009-05-04DOI: 10.1109/RADAR.2009.4976968
M. Reiher, Bin Yang
In LFMCW (linear frequency modulated continuous wave) radar, there is a nonzero probability for mismatches to occur under certain conditions. This probability strongly depends on the modulation employed as well as on the distribution of targets in the radar's field of view, i.e. the application of the radar sensor. Hence to reduce mismatches in a given application, an effective approach is to carefully design the modulation used. Instead of utilizing extensive simulations, we derive the distribution of mismatches analytically, solely based on the modulation parameters and a given distribution of targets. Based on that mismatch distribution, an application-specific optimization of the modulation is feasible.
{"title":"Derivation of the frequency mismatch probability in linear FMCW radar based on target distribution","authors":"M. Reiher, Bin Yang","doi":"10.1109/RADAR.2009.4976968","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4976968","url":null,"abstract":"In LFMCW (linear frequency modulated continuous wave) radar, there is a nonzero probability for mismatches to occur under certain conditions. This probability strongly depends on the modulation employed as well as on the distribution of targets in the radar's field of view, i.e. the application of the radar sensor. Hence to reduce mismatches in a given application, an effective approach is to carefully design the modulation used. Instead of utilizing extensive simulations, we derive the distribution of mismatches analytically, solely based on the modulation parameters and a given distribution of targets. Based on that mismatch distribution, an application-specific optimization of the modulation is feasible.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133800769","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 : 2009-05-04DOI: 10.1109/RADAR.2009.4977005
E. Pancera, T. Zwick, W. Wiesbeck
In this paper the time domain responses of UWB Radar signals from scattering targets are analyzed. In particular, the aim of this paper is to investigate the pulse distortion of UWB Radar signals by a scattering object, i.e. how does the scattered signal vary with respect to the Radar signal incident on the object itself. The investigation is performed analyzing the polarimetric responses of different targets (flat plate, sphere). The time domain description (impulse response and pulse preserving capability) of a generic scattering process is mathematically described. Then for verification and application, these prior defined quantities are experimentally measured for two particular targets, a flat plate and a sphere.
{"title":"Correlation properties of UWB Radar target impulse responses","authors":"E. Pancera, T. Zwick, W. Wiesbeck","doi":"10.1109/RADAR.2009.4977005","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4977005","url":null,"abstract":"In this paper the time domain responses of UWB Radar signals from scattering targets are analyzed. In particular, the aim of this paper is to investigate the pulse distortion of UWB Radar signals by a scattering object, i.e. how does the scattered signal vary with respect to the Radar signal incident on the object itself. The investigation is performed analyzing the polarimetric responses of different targets (flat plate, sphere). The time domain description (impulse response and pulse preserving capability) of a generic scattering process is mathematically described. Then for verification and application, these prior defined quantities are experimentally measured for two particular targets, a flat plate and a sphere.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"90 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115577849","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 : 2009-05-04DOI: 10.1109/RADAR.2009.4977097
D. Long
Post processing reconstruction and resolution enhancement algorithms can be applied to Cassini Titan Radar Mapper data to improve the image resolution for scatterometermode imagery. Reconstruction algorithms can also yield enhanced resolution images when multiple passes are combined. This paper briefly describes the application of the AVE and the Scatterometer Image Reconstruction (SIR) algorithms to Cassini Radar data. Some sample results are provided. A comparison with the Backus-Gilbert algorithm is also provided.
{"title":"Spatial resolution enhancement of Cassini Titan Radar mapper data","authors":"D. Long","doi":"10.1109/RADAR.2009.4977097","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4977097","url":null,"abstract":"Post processing reconstruction and resolution enhancement algorithms can be applied to Cassini Titan Radar Mapper data to improve the image resolution for scatterometermode imagery. Reconstruction algorithms can also yield enhanced resolution images when multiple passes are combined. This paper briefly describes the application of the AVE and the Scatterometer Image Reconstruction (SIR) algorithms to Cassini Radar data. Some sample results are provided. A comparison with the Backus-Gilbert algorithm is also provided.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"35 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116215765","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 : 2009-05-04DOI: 10.1109/RADAR.2009.4977085
Lei Wang, P. Brennan
Snow avalanche are geophysical flows that pose a significant threat to life in alpine areas. To understand the behaviors of avalanche flows requires huge amount of accurate data. A developing 5.3 GHz RADAR system at UCL will give geographers a chance to find the velocities and velocity fluctuation of avalanche flow. This RADAR will be the first highresolution (1m) instrument for these geophysical phenomena. This paper introduces this innovative RADAR system and also gives its developing status.
{"title":"Avalanche flow imaging RADAR","authors":"Lei Wang, P. Brennan","doi":"10.1109/RADAR.2009.4977085","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4977085","url":null,"abstract":"Snow avalanche are geophysical flows that pose a significant threat to life in alpine areas. To understand the behaviors of avalanche flows requires huge amount of accurate data. A developing 5.3 GHz RADAR system at UCL will give geographers a chance to find the velocities and velocity fluctuation of avalanche flow. This RADAR will be the first highresolution (1m) instrument for these geophysical phenomena. This paper introduces this innovative RADAR system and also gives its developing status.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"36 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124805316","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 : 2009-05-04DOI: 10.1109/RADAR.2009.4976983
D. Brunner, L. Bruzzone, A. Ferro, G. Lemoine
The double bounce effect of buildings is an important characteristic in very high resolution (VHR) synthetic aperture radar (SAR) images. It typically appears as a strong scattering mechanism caused by a corner reflector, which is made of the front wall of a building and its surrounding ground area. In order to exploit this feature effectively for automatic building detection and reconstruction techniques, empirical studies on real VHR SAR images need to investigate the stability of the double bounce mechanism with respect to changes in the viewing configuration and material properties. Thus, this paper addresses the analysis of the relation between the double bounce effect and the aspect angle of a building for two different ground materials, by analyzing two TerraSAR-X VHR spaceborne SAR images. Furthermore, we compare the empirical results with the simulations obtained by theoretical electromagnetic models. We show that if the buildings are surrounded by asphalt, the strength of the double bounce decreases significantly from 0 to 10 degrees aspect angle, while it decreases moderately for higher values of the aspect angle. Considering buildings which are surrounded by grass, the drop of the strength for low values of the aspect angle is less evident, but it is more constant on the full range of aspect angles.
{"title":"Analysis of the reliability of the double bounce scattering mechanism for detecting buildings in VHR SAR images","authors":"D. Brunner, L. Bruzzone, A. Ferro, G. Lemoine","doi":"10.1109/RADAR.2009.4976983","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4976983","url":null,"abstract":"The double bounce effect of buildings is an important characteristic in very high resolution (VHR) synthetic aperture radar (SAR) images. It typically appears as a strong scattering mechanism caused by a corner reflector, which is made of the front wall of a building and its surrounding ground area. In order to exploit this feature effectively for automatic building detection and reconstruction techniques, empirical studies on real VHR SAR images need to investigate the stability of the double bounce mechanism with respect to changes in the viewing configuration and material properties. Thus, this paper addresses the analysis of the relation between the double bounce effect and the aspect angle of a building for two different ground materials, by analyzing two TerraSAR-X VHR spaceborne SAR images. Furthermore, we compare the empirical results with the simulations obtained by theoretical electromagnetic models. We show that if the buildings are surrounded by asphalt, the strength of the double bounce decreases significantly from 0 to 10 degrees aspect angle, while it decreases moderately for higher values of the aspect angle. Considering buildings which are surrounded by grass, the drop of the strength for low values of the aspect angle is less evident, but it is more constant on the full range of aspect angles.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125148328","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 : 2009-05-04DOI: 10.1109/RADAR.2009.4977024
D. Garmatyuk, J. Schuerger, Kyle Kauffman, Scott Spalding
This paper describes the design and architectural composition of a radar system built on OFDM platform. The radar signal is generated digitally by forming an arbitrary-length vector of OFDM sub-carrier amplitudes and translating it in analog format via 1000 Ms/s D/A conversion. The resultant baseband signal has a bandwidth of 500 MHz, and variable number and composition of sub-carriers, which may be changed on a pulse-to-pulse basis. The signal is upconverted to 7.5 GHz carrier frequency and emitted via small-form horn antenna. The receiver includes 1 Gs/s A/D converter and processing is performed in frequency domain. The system is currently configured for short-range applications (3–5 m) and can be used as radar or communication unit without any changes to hardware and with very minimal changes to software. Experimental results from high-resolution range profile imaging and broadband data communications are presented and discussed.
{"title":"Wideband OFDM system for radar and communications","authors":"D. Garmatyuk, J. Schuerger, Kyle Kauffman, Scott Spalding","doi":"10.1109/RADAR.2009.4977024","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4977024","url":null,"abstract":"This paper describes the design and architectural composition of a radar system built on OFDM platform. The radar signal is generated digitally by forming an arbitrary-length vector of OFDM sub-carrier amplitudes and translating it in analog format via 1000 Ms/s D/A conversion. The resultant baseband signal has a bandwidth of 500 MHz, and variable number and composition of sub-carriers, which may be changed on a pulse-to-pulse basis. The signal is upconverted to 7.5 GHz carrier frequency and emitted via small-form horn antenna. The receiver includes 1 Gs/s A/D converter and processing is performed in frequency domain. The system is currently configured for short-range applications (3–5 m) and can be used as radar or communication unit without any changes to hardware and with very minimal changes to software. Experimental results from high-resolution range profile imaging and broadband data communications are presented and discussed.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"68 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130282016","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 : 2009-05-04DOI: 10.1109/RADAR.2009.4977016
Jian Wang, M. Gerecke, E. Brookner, P. Cornwell, J. Farr
This paper presents an overview of a service life extension program that is being applied to the continental US Long Range Radar (LRR) network. Initially the architecture of the system is presented and key components selected for upgrade are identified. In addition to hardware upgrades innovative signal processing algorithms have also been added. The LRR consists of 68 radars that are used for the joint purposes of air traffic control and surveillance. The upgraded radar consists of a solid state transmitter, a state-of-the-art receiver and signal data processor. With advanced signal processing algorithms, the upgraded radar system provides 200 nmi coverage in natural interference environment while minimizing the false alarms. The radar has also been upgraded to enhance weather detection performance.
{"title":"Design and implementation of Long Range Radar service life extension","authors":"Jian Wang, M. Gerecke, E. Brookner, P. Cornwell, J. Farr","doi":"10.1109/RADAR.2009.4977016","DOIUrl":"https://doi.org/10.1109/RADAR.2009.4977016","url":null,"abstract":"This paper presents an overview of a service life extension program that is being applied to the continental US Long Range Radar (LRR) network. Initially the architecture of the system is presented and key components selected for upgrade are identified. In addition to hardware upgrades innovative signal processing algorithms have also been added. The LRR consists of 68 radars that are used for the joint purposes of air traffic control and surveillance. The upgraded radar consists of a solid state transmitter, a state-of-the-art receiver and signal data processor. With advanced signal processing algorithms, the upgraded radar system provides 200 nmi coverage in natural interference environment while minimizing the false alarms. The radar has also been upgraded to enhance weather detection performance.","PeriodicalId":346898,"journal":{"name":"2009 IEEE Radar Conference","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2009-05-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124520785","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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