Pub Date : 1993-10-18DOI: 10.1109/OCEANS.1993.326210
M. S. Moustafa, G. Hebenstreit, M. Mandelberg
The Sun-based oceanographic analysis package, SOTS (SASEA On The Sun), was developed to provide near-real-time analysis of oceanographic and acoustic conditions during large-scale at-sea experiments and underwater system development tests. SOTS can be ship-based, land-based, or both. The system enables scientists participating in such tests to quickly evaluate the oceanographic/acoustic conditions present and to respond to changes in conditions or differences between the expected and actual environments. SOTS capabilities include profile editing, database utilities, statistical tools, and graphical displays. Because of the many oceanographic and acoustic data analysis capabilities and applications that exist in the SOTS system potential applications include oceanographic site assessments, modeling and analysis of data fields, generation of 3D sound speed fields, and acoustic tomography.<>
基于太阳的海洋学分析包SOTS (SASEA On The Sun)是为了在大规模海上实验和水下系统开发测试期间提供近实时的海洋学和声学条件分析而开发的。sot可以是舰基的，陆基的，或者两者兼而有之。该系统使参与此类测试的科学家能够快速评估当前的海洋/声学条件，并对条件的变化或预期环境与实际环境之间的差异做出反应。SOTS功能包括配置文件编辑、数据库实用程序、统计工具和图形显示。由于SOTS系统中存在许多海洋和声学数据分析能力和应用，潜在的应用包括海洋现场评估、数据场建模和分析、3D声速场生成和声学层析成像。
{"title":"SOTS: a Sun-based system for oceanographic analysis","authors":"M. S. Moustafa, G. Hebenstreit, M. Mandelberg","doi":"10.1109/OCEANS.1993.326210","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326210","url":null,"abstract":"The Sun-based oceanographic analysis package, SOTS (SASEA On The Sun), was developed to provide near-real-time analysis of oceanographic and acoustic conditions during large-scale at-sea experiments and underwater system development tests. SOTS can be ship-based, land-based, or both. The system enables scientists participating in such tests to quickly evaluate the oceanographic/acoustic conditions present and to respond to changes in conditions or differences between the expected and actual environments. SOTS capabilities include profile editing, database utilities, statistical tools, and graphical displays. Because of the many oceanographic and acoustic data analysis capabilities and applications that exist in the SOTS system potential applications include oceanographic site assessments, modeling and analysis of data fields, generation of 3D sound speed fields, and acoustic tomography.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114068453","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326218
Jean‐Marie Q. D. Tran, W. Hodgkiss
Deals with the manifestation of downslope converted continental shelf noise sources (primarily ships) in the matched-field processor (MFP) ambiguity surface. Of interest is how noise sources outside the range of interest leak into the ambiguity surface through the sidelobe structure of the effective MFP beam (or cell) pattern. This study is carried out with simulations using the parabolic equation model. A shallow 18 Hz source is assumed deployed at various locations on the continental slope, 1750 km from a 1000 m long vertical line array. The MFP search window extends in range across 500 km and in depth down to 1000 m. Shallow sources on the slope show up in the MFP ambiguity surface as deep peaks when downslope conversion takes place. Shallow sources at locations on the slope or in deep water adjacent to the slope where downslope conversion does not take place, appear in the MFP ambiguity surface as shallow sources.<>
{"title":"Ambiguity surface manifestation of downslope converted noise sources","authors":"Jean‐Marie Q. D. Tran, W. Hodgkiss","doi":"10.1109/OCEANS.1993.326218","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326218","url":null,"abstract":"Deals with the manifestation of downslope converted continental shelf noise sources (primarily ships) in the matched-field processor (MFP) ambiguity surface. Of interest is how noise sources outside the range of interest leak into the ambiguity surface through the sidelobe structure of the effective MFP beam (or cell) pattern. This study is carried out with simulations using the parabolic equation model. A shallow 18 Hz source is assumed deployed at various locations on the continental slope, 1750 km from a 1000 m long vertical line array. The MFP search window extends in range across 500 km and in depth down to 1000 m. Shallow sources on the slope show up in the MFP ambiguity surface as deep peaks when downslope conversion takes place. Shallow sources at locations on the slope or in deep water adjacent to the slope where downslope conversion does not take place, appear in the MFP ambiguity surface as shallow sources.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"28 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121762020","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326111
M. Erlic, W.-s. Lu
In this paper an improved manipulator joint velocity observer is presented which is reduced in its order. The observer provides a smooth velocity estimate to be used by a trajectory tracking controller. The observer, controller and manipulator form a system where the observer error as well as the position and velocity tracking errors tend to zero asymptotically. The proposed observer is compared to numerical differentiation plus filtering as a means to provide a velocity signal which is used in control. When considering joint position signals corrupted with measurement noise, it is found that the proposed observer is superior in its performance compared to numerical differentiation plus filtering.<>
{"title":"A reduced order observer for underwater manipulators using potentiometers for position measurements","authors":"M. Erlic, W.-s. Lu","doi":"10.1109/OCEANS.1993.326111","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326111","url":null,"abstract":"In this paper an improved manipulator joint velocity observer is presented which is reduced in its order. The observer provides a smooth velocity estimate to be used by a trajectory tracking controller. The observer, controller and manipulator form a system where the observer error as well as the position and velocity tracking errors tend to zero asymptotically. The proposed observer is compared to numerical differentiation plus filtering as a means to provide a velocity signal which is used in control. When considering joint position signals corrupted with measurement noise, it is found that the proposed observer is superior in its performance compared to numerical differentiation plus filtering.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123072439","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326155
G. Langran, J. Larson, T. G. Baybrook
Outlines issues of managing coastal environmental information and suggests ways that technology addresses these issues. In particular, the marine environment's temporality and multidimensionality cause problems for geographic information systems designed to emulate the map. Systems that provide a richer descriptive environment offer new hope, since they permit numerical modeling of entities and their interrelationships. Such methods are useful to describe motion, cycles, fluid dynamics, and change in the coastal region.<>
{"title":"Coastal environmental monitoring using GIS technology","authors":"G. Langran, J. Larson, T. G. Baybrook","doi":"10.1109/OCEANS.1993.326155","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326155","url":null,"abstract":"Outlines issues of managing coastal environmental information and suggests ways that technology addresses these issues. In particular, the marine environment's temporality and multidimensionality cause problems for geographic information systems designed to emulate the map. Systems that provide a richer descriptive environment offer new hope, since they permit numerical modeling of entities and their interrelationships. Such methods are useful to describe motion, cycles, fluid dynamics, and change in the coastal region.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"39 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127017285","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326102
En-Fang Sang, H. Yeh
Several modified Least Mean Square (LMS) algorithms are studied in order to improve the rate of convergence of the regular LMS algorithm. The performance of these modified LMS algorithms is evaluated by simulations. It shows that the error feedback LMS algorithm converges much faster then all other modified LMS algorithms including regular LMS algorithm.<>
{"title":"Modified LMS algorithms for high speed underwater acoustic signal processing","authors":"En-Fang Sang, H. Yeh","doi":"10.1109/OCEANS.1993.326102","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326102","url":null,"abstract":"Several modified Least Mean Square (LMS) algorithms are studied in order to improve the rate of convergence of the regular LMS algorithm. The performance of these modified LMS algorithms is evaluated by simulations. It shows that the error feedback LMS algorithm converges much faster then all other modified LMS algorithms including regular LMS algorithm.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"43 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127623992","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326191
R. B. Huseby, O. Milvang, A. Solberg, K. W. Bjerde
The development of reliable methods for automatic seabed classification enjoys widespread interest at the present time. In this article, statistical methods for seabed classification from backscatter sonar data are investigated. The classification rule is derived from the Bayes decision rule and involves a probability model of the features extracted from multibeam echosounder data. The features are based on the backscatter distribution, the spectral distribution, and the backscatter-level co-occurence. The authors also present procedures for detection of seabed of unknown type and classification of pixels as a mixture of two different classes. Raw backscatter data from the Simrad EM 1000 Multibeam Echo Sounder are used. The results show that it is possible to differentiate between seabeds of various sediment types.<>
{"title":"Seabed classification from multibeam echosounder data using statistical methods","authors":"R. B. Huseby, O. Milvang, A. Solberg, K. W. Bjerde","doi":"10.1109/OCEANS.1993.326191","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326191","url":null,"abstract":"The development of reliable methods for automatic seabed classification enjoys widespread interest at the present time. In this article, statistical methods for seabed classification from backscatter sonar data are investigated. The classification rule is derived from the Bayes decision rule and involves a probability model of the features extracted from multibeam echosounder data. The features are based on the backscatter distribution, the spectral distribution, and the backscatter-level co-occurence. The authors also present procedures for detection of seabed of unknown type and classification of pixels as a mixture of two different classes. Raw backscatter data from the Simrad EM 1000 Multibeam Echo Sounder are used. The results show that it is possible to differentiate between seabeds of various sediment types.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"621 ","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114058608","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326158
C. Blyth, M. A. Caldwell, T. Fyles, B. Smiley
The Continental and Oceanographic Data Information System (CODIS) is a custom software/database application developed to provide an on-line computer catalogue or inventory of scientific data gathered during environmental studies in Canadian West Coast and Arctic waters and in the Fraser River. CODIS was developed in conjunction with Fisheries and Oceans Canada and the University of Victoria. Information about the disciplines: ocean chemistry, physical oceanography, fish, mammals, zoobenthos, plankton and continental chemistry, with the intent of including more disciplines in the future. The purpose of the inventory was to assemble, condense and appraise all available documentation in order to assist the researcher or environmental manager in identifying and locating the most suitable data sets for specific applications. The system includes data from the Fisheries and Oceans Canada, Arctic Data Compilation and Appraisal and West Coast Data Compilation and Appraisal catalogues and data collected by the University of Victoria. The information has been assembled from a variety of sources. The system includes information concerning data quality based on suitability of methods and completeness of documentation. The data quality rating is an objective scale that grades data according to their ability to be compared to data described in other data sets. The purpose of the data rating is to provide users with a guide to the level of confidence they can place on conclusions drawn from the data and it provides an indication of how applicable the data are for other purposes. CODIS permits the data to be edited while maintaining strict adherence to data quality protocols.<>
{"title":"The Continental and Oceanographic Data Information System (CODIS)","authors":"C. Blyth, M. A. Caldwell, T. Fyles, B. Smiley","doi":"10.1109/OCEANS.1993.326158","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326158","url":null,"abstract":"The Continental and Oceanographic Data Information System (CODIS) is a custom software/database application developed to provide an on-line computer catalogue or inventory of scientific data gathered during environmental studies in Canadian West Coast and Arctic waters and in the Fraser River. CODIS was developed in conjunction with Fisheries and Oceans Canada and the University of Victoria. Information about the disciplines: ocean chemistry, physical oceanography, fish, mammals, zoobenthos, plankton and continental chemistry, with the intent of including more disciplines in the future. The purpose of the inventory was to assemble, condense and appraise all available documentation in order to assist the researcher or environmental manager in identifying and locating the most suitable data sets for specific applications. The system includes data from the Fisheries and Oceans Canada, Arctic Data Compilation and Appraisal and West Coast Data Compilation and Appraisal catalogues and data collected by the University of Victoria. The information has been assembled from a variety of sources. The system includes information concerning data quality based on suitability of methods and completeness of documentation. The data quality rating is an objective scale that grades data according to their ability to be compared to data described in other data sets. The purpose of the data rating is to provide users with a guide to the level of confidence they can place on conclusions drawn from the data and it provides an indication of how applicable the data are for other purposes. CODIS permits the data to be edited while maintaining strict adherence to data quality protocols.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122465649","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326146
F. Parthiot, J. Denis
IFREMER-French Institute for Sea Exploration and Exploitation-is currently operating manned submersibles, towed sonars and ROVs down to 6000 m. IFREMER are replacing their positioning system resting on long base line (LBL) by a new positioning system called POSIDONIA which is under development at the company group Thomson Sintra ASM and Mors Environment. This replacement aims to reduce operators time and overall costs by improving accuracy, reliability and flexibility in comparison with the existing systems. To achieve these characteristics, the POSIDONIA positioning system is of a new breed which combines a short base line (SBL) and an ultra short base line (USBL). It has been designed to operate in noisy environments and get rid of multipath effects, to compensate for the lack of precise radio navigation, and generally to comply with the various task requirements. Therefore, not only has the acoustic signal processing been optimized, but also the beacon functionalities to give full versatility. In addition, the need of a high precision vertical and heading reference unit (VHRU), to make up for the vessel attitude, has induced the definition of a hybrid VHRU based on both GPS and inertial sensors.<>
{"title":"A better way to navigate on deep sea floors","authors":"F. Parthiot, J. Denis","doi":"10.1109/OCEANS.1993.326146","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326146","url":null,"abstract":"IFREMER-French Institute for Sea Exploration and Exploitation-is currently operating manned submersibles, towed sonars and ROVs down to 6000 m. IFREMER are replacing their positioning system resting on long base line (LBL) by a new positioning system called POSIDONIA which is under development at the company group Thomson Sintra ASM and Mors Environment. This replacement aims to reduce operators time and overall costs by improving accuracy, reliability and flexibility in comparison with the existing systems. To achieve these characteristics, the POSIDONIA positioning system is of a new breed which combines a short base line (SBL) and an ultra short base line (USBL). It has been designed to operate in noisy environments and get rid of multipath effects, to compensate for the lack of precise radio navigation, and generally to comply with the various task requirements. Therefore, not only has the acoustic signal processing been optimized, but also the beacon functionalities to give full versatility. In addition, the need of a high precision vertical and heading reference unit (VHRU), to make up for the vessel attitude, has induced the definition of a hybrid VHRU based on both GPS and inertial sensors.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124029768","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326226
R. Coates
The paper first attempts to provide a framework for the underwater acoustic communication system. An acoustic frequency band allocation, analogous to that used by radio engineers, is proposed. Similarly, the "shallow" channel is defined and the conditions pertaining to "high" bit rate explored. Finally the paper, using this framework, discusses the performance of a range of communication systems developed at the University of Birmingham, UK.<>
{"title":"Underwater acoustic communications","authors":"R. Coates","doi":"10.1109/OCEANS.1993.326226","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326226","url":null,"abstract":"The paper first attempts to provide a framework for the underwater acoustic communication system. An acoustic frequency band allocation, analogous to that used by radio engineers, is proposed. Similarly, the \"shallow\" channel is defined and the conditions pertaining to \"high\" bit rate explored. Finally the paper, using this framework, discusses the performance of a range of communication systems developed at the University of Birmingham, UK.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"99 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124194336","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 : 1993-10-18DOI: 10.1109/OCEANS.1993.326059
B. Nutzel, H. Herwig, A. Schmidt
Results of the experiment SAXON Phase 2 which was conducted in November 1991 at the German Research Platform NORDSEE are presented. The experiment was designed to measure the acoustic and electromagnetic backscattering strength of the sea surface simultaneously and at the same sonar and radar wavelength. The grazing angle dependence was investigated at angles from 20/spl deg/ to 70/spl deg/. Backscattering from the same spot of the sea surface was measured at a grazing angle of 18/spl deg/ for both systems. The sonar frequencies were 50, 26.5, and 5 kHz corresponding to radar frequencies of 10, 5.3, and 1 GHz (X-, C-, and L-band), respectively. Data were collected at wind speeds ranging from 0 to 21 m/s. The results exhibit excellent correlation between sonar and radar backscattering in the low wind speed regime at all frequencies. At higher wind speeds, bubbles caused by breaking waves are the dominant acoustic backscattering mechanism at high sonar frequencies. In this case both systems no longer see the same scatterers and the correlation decreases. The parameter combinations of wind speed and sonar and radar frequency, for which the backscatter occurs from the sea surface only, are given for a grazing angle of 45.<>
{"title":"Acoustic and microwave backscattering of the sea surface","authors":"B. Nutzel, H. Herwig, A. Schmidt","doi":"10.1109/OCEANS.1993.326059","DOIUrl":"https://doi.org/10.1109/OCEANS.1993.326059","url":null,"abstract":"Results of the experiment SAXON Phase 2 which was conducted in November 1991 at the German Research Platform NORDSEE are presented. The experiment was designed to measure the acoustic and electromagnetic backscattering strength of the sea surface simultaneously and at the same sonar and radar wavelength. The grazing angle dependence was investigated at angles from 20/spl deg/ to 70/spl deg/. Backscattering from the same spot of the sea surface was measured at a grazing angle of 18/spl deg/ for both systems. The sonar frequencies were 50, 26.5, and 5 kHz corresponding to radar frequencies of 10, 5.3, and 1 GHz (X-, C-, and L-band), respectively. Data were collected at wind speeds ranging from 0 to 21 m/s. The results exhibit excellent correlation between sonar and radar backscattering in the low wind speed regime at all frequencies. At higher wind speeds, bubbles caused by breaking waves are the dominant acoustic backscattering mechanism at high sonar frequencies. In this case both systems no longer see the same scatterers and the correlation decreases. The parameter combinations of wind speed and sonar and radar frequency, for which the backscatter occurs from the sea surface only, are given for a grazing angle of 45.<<ETX>>","PeriodicalId":130255,"journal":{"name":"Proceedings of OCEANS '93","volume":"61 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"1993-10-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124576125","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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