Pub Date : 2011-05-17DOI: 10.1109/CONATEL.2011.5958660
Miguel A. Ferrer, Francisco Vargas, A. Morales
This paper presents a contactless hand based biometric identification system using geometric and palm features. Hand images are acquired using two commercial webcams with 1200×1600 pixel resolution which are refered to as the “IR” and “visible” webcams. The IR webcam has been modified by exchanging the IR filter with a visible filter lens and reducing the gain and exposure time to improve the hand contour extraction. The hand was illuminated using 24 infra-red LEDs and 4 white light LEDs. Images acquired from the IR webcam were binarized and the normalized widths from the index to little finger were used as features. A Least Square Support Vector Machine was then used for verification. The palm features were obtained by the Orthogonal Line Ordinal Features approach applied to the image acquired by the visible webcam. The hand image from the visible webcam was segmented using an Active Shape Model guided by the hand contour from the IR webcam as an initial guest. A Hamming distance was used as verifier. More than 8000 hand images from three public databases were used in order to compare the features extraction approaches. A score level fusion of both biometrics is performed obtaining an Equal Error Rate of 0.17% with a proprietary database of 100 users acquired with the proposed device.
{"title":"BiSpectral contactless hand based biometric system","authors":"Miguel A. Ferrer, Francisco Vargas, A. Morales","doi":"10.1109/CONATEL.2011.5958660","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958660","url":null,"abstract":"This paper presents a contactless hand based biometric identification system using geometric and palm features. Hand images are acquired using two commercial webcams with 1200×1600 pixel resolution which are refered to as the “IR” and “visible” webcams. The IR webcam has been modified by exchanging the IR filter with a visible filter lens and reducing the gain and exposure time to improve the hand contour extraction. The hand was illuminated using 24 infra-red LEDs and 4 white light LEDs. Images acquired from the IR webcam were binarized and the normalized widths from the index to little finger were used as features. A Least Square Support Vector Machine was then used for verification. The palm features were obtained by the Orthogonal Line Ordinal Features approach applied to the image acquired by the visible webcam. The hand image from the visible webcam was segmented using an Active Shape Model guided by the hand contour from the IR webcam as an initial guest. A Hamming distance was used as verifier. More than 8000 hand images from three public databases were used in order to compare the features extraction approaches. A score level fusion of both biometrics is performed obtaining an Equal Error Rate of 0.17% with a proprietary database of 100 users acquired with the proposed device.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129686047","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 : 2011-05-17DOI: 10.1109/CONATEL.2011.5958661
M. Chuchon, M. Quispe, J. Samaniego, Guillermo Kemper, Daniel Diaz
Evaluation of coverage and service of television systems requires the application of normalized procedures in order to compare data obtained in different measurement campaigns. There is a large quantity of documentation about general aspects of these processes, which is useful in the stage of planning. This is not the case when detailed aspects like the correct configuration of the measuring equipment or processing of collected data are required. This document pretends to provide some practical information about testing of coverage and service of analog and digital television transmitter systems.
{"title":"Coverage and service testing of Terrestrial television systems: Practical aspects","authors":"M. Chuchon, M. Quispe, J. Samaniego, Guillermo Kemper, Daniel Diaz","doi":"10.1109/CONATEL.2011.5958661","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958661","url":null,"abstract":"Evaluation of coverage and service of television systems requires the application of normalized procedures in order to compare data obtained in different measurement campaigns. There is a large quantity of documentation about general aspects of these processes, which is useful in the stage of planning. This is not the case when detailed aspects like the correct configuration of the measuring equipment or processing of collected data are required. This document pretends to provide some practical information about testing of coverage and service of analog and digital television transmitter systems.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126628970","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 : 2011-05-17DOI: 10.1109/CONATEL.2011.5958672
Y. Omar
QuantPrivTel — Quantum Private Telecommunications is an ongoing research project that joins the theoretical expertise of the Security and Quantum Information Group (SQIG) at Instituto de Telecomunicações (IT) in Lisbon, Portugal, and the skills in quantum optics experiments of the Optical Communications group (OC-Av) at IT Aveiro, Portugal, to tackle new challenges in the emergent and multidisciplinary area of quantum private telecommunications. After a brief introduction to quantum information and quantum telecommunication, we will present the main results achieved by the project team so far, namely a quantum-enhanced message authentication protocol and a quantum contract signing protocol, as well as the implementation of quantum channels with optical fibers.
{"title":"Quantum Private Telecommunications: A project at Instituto de Telecomunicações, Portugal","authors":"Y. Omar","doi":"10.1109/CONATEL.2011.5958672","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958672","url":null,"abstract":"QuantPrivTel — Quantum Private Telecommunications is an ongoing research project that joins the theoretical expertise of the Security and Quantum Information Group (SQIG) at Instituto de Telecomunicações (IT) in Lisbon, Portugal, and the skills in quantum optics experiments of the Optical Communications group (OC-Av) at IT Aveiro, Portugal, to tackle new challenges in the emergent and multidisciplinary area of quantum private telecommunications. After a brief introduction to quantum information and quantum telecommunication, we will present the main results achieved by the project team so far, namely a quantum-enhanced message authentication protocol and a quantum contract signing protocol, as well as the implementation of quantum channels with optical fibers.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124710913","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 : 2011-05-17DOI: 10.1109/CONATEL.2011.5958656
Danny Múnera, N. Gaviria
Cross-Layer design is a new technique which can be used to improve the performance in wireless sensor networks under the severe restrictions of the energy consumption. Cross-layer techniques intended to create an optimization of the limited resources, taking into account factors associated with different layers of traditional communication schemes, opening a new way for the development of complex communications mechanism. However, because these techniques are based on a non-standard architecture, its structure has a lot of dissimilar characteristics that obstruct a comprehensive comparison of its performance. In this paper, we propose a framework for simulation and evaluation of cross-layer techniques in wireless sensor networks. Our framework promotes a fairness comparison of different communication schemes, a realistic model simulation, an experiment design and a rigorous analysis of results with ANOVA (Analysis of Variance) technique. As a case study, we test our comparative simulation framework with to two popular cross-layer schemes showing the facility of use and the result of the analysis of the data.
{"title":"A framework for simulation and evaluation of cross-layer techniques in wireless sensor networks","authors":"Danny Múnera, N. Gaviria","doi":"10.1109/CONATEL.2011.5958656","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958656","url":null,"abstract":"Cross-Layer design is a new technique which can be used to improve the performance in wireless sensor networks under the severe restrictions of the energy consumption. Cross-layer techniques intended to create an optimization of the limited resources, taking into account factors associated with different layers of traditional communication schemes, opening a new way for the development of complex communications mechanism. However, because these techniques are based on a non-standard architecture, its structure has a lot of dissimilar characteristics that obstruct a comprehensive comparison of its performance. In this paper, we propose a framework for simulation and evaluation of cross-layer techniques in wireless sensor networks. Our framework promotes a fairness comparison of different communication schemes, a realistic model simulation, an experiment design and a rigorous analysis of results with ANOVA (Analysis of Variance) technique. As a case study, we test our comparative simulation framework with to two popular cross-layer schemes showing the facility of use and the result of the analysis of the data.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"122007636","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 : 2011-05-17DOI: 10.1109/CONATEL.2011.5958664
Marcelo Ribeiro, Golberi de Salvador Ferreira, H. Sterner
The consequences of the current electronic equipment market demands is causing designers to develop ever faster circuits in ever smaller devices. The miniaturization of circuits together with increased operating speeds shows several functional difficulties, which require skills and knowledge of the designer so that the final product fits into operation standards and can be produced. The objectives of this research are to address the adverse effects on the operation of electronic equipment, demystifying the network of influences present when a circuit is in operation and find methodologies to identify and reduce critical problems on these devices. The study was done on hypothetical printed circuit boards, created specifically to simulate and demonstrate the desired effects. Although hypothetical, part of its settings can be found in commercially produced plates. The results were obtained through numerical models, computational simulations and measurements in physical prototypes. Through these, it was possible to identify critical topologies, asymmetries to be avoided and develop methodologies to avoid adverse problems. Another important point was the validation of theories and the comparison of the results measured in physical prototypes with the results originated by simulation and numerical modeling in order to trace its fidelity with real models.
{"title":"FR-4 microstrip transmission lines behavior in high frequency range","authors":"Marcelo Ribeiro, Golberi de Salvador Ferreira, H. Sterner","doi":"10.1109/CONATEL.2011.5958664","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958664","url":null,"abstract":"The consequences of the current electronic equipment market demands is causing designers to develop ever faster circuits in ever smaller devices. The miniaturization of circuits together with increased operating speeds shows several functional difficulties, which require skills and knowledge of the designer so that the final product fits into operation standards and can be produced. The objectives of this research are to address the adverse effects on the operation of electronic equipment, demystifying the network of influences present when a circuit is in operation and find methodologies to identify and reduce critical problems on these devices. The study was done on hypothetical printed circuit boards, created specifically to simulate and demonstrate the desired effects. Although hypothetical, part of its settings can be found in commercially produced plates. The results were obtained through numerical models, computational simulations and measurements in physical prototypes. Through these, it was possible to identify critical topologies, asymmetries to be avoided and develop methodologies to avoid adverse problems. Another important point was the validation of theories and the comparison of the results measured in physical prototypes with the results originated by simulation and numerical modeling in order to trace its fidelity with real models.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125439648","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}
The objective of this project was to develop an identification system for moving vehicles using radio frequency, with the aim of recording the times in which buses belonging to the urban transport system of passengers make their pass by a set of checkpoints located over their routes. The identification system was designed and implemented using XBee ® modules, which allows assigning a unique number for each car to identify it wirelessly to 30 m away. The information collected by the system, like the time of detection of vehicles is transmitted to a database located on a remote server, in order to obtain statistics and reports of the frequency of transport routes at any instant of time. The transmission of information is performed by an embedded Linux system using an Internet connection, which also uses one of its USARTs to manage the communication with RF modules. This project achieved an application to monitor the path and performance of urban transport routes ensuring the reliability and integrity of the data collected.
{"title":"System for identification and control of arrival of vehicles","authors":"Camilo Alexey Suarez Buitrago, Jhon Jairo Ramírez Echeverry","doi":"10.1109/CONATEL.2011.5958674","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958674","url":null,"abstract":"The objective of this project was to develop an identification system for moving vehicles using radio frequency, with the aim of recording the times in which buses belonging to the urban transport system of passengers make their pass by a set of checkpoints located over their routes. The identification system was designed and implemented using XBee ® modules, which allows assigning a unique number for each car to identify it wirelessly to 30 m away. The information collected by the system, like the time of detection of vehicles is transmitted to a database located on a remote server, in order to obtain statistics and reports of the frequency of transport routes at any instant of time. The transmission of information is performed by an embedded Linux system using an Internet connection, which also uses one of its USARTs to manage the communication with RF modules. This project achieved an application to monitor the path and performance of urban transport routes ensuring the reliability and integrity of the data collected.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125571504","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 : 2011-05-17DOI: 10.1109/CONATEL.2011.5958657
Luis F. Abanto-Leon, Guillermo Kemper Vasquez, J. Telles
ITU-R BS.1387 states a method for objective assessment of perceived audio quality. This Recommendation, known also as PEAQ (Perceptual Evaluation of Audio Quality) is based on a psychoacoustic model of the human ear and was standardized by the International Telecommunications Union as an alternative to subjective tests, which are expensive and time-consuming processes. PEAQ combines various physiological and psycho-acoustical properties of the human ear to give a measure of the quality difference between a reference audio and a test audio. The reference audio signal could be considered as a distortion-free source, whereas the test signal is a distorted version of the reference, which may have audible artifacts because of compression. The algorithm computes the Model Output Variables (MOVs) which are mapped to a single quality measure, Objective Difference Grade (ODG), using a three-layer perceptron artificial neural network. The ODG estimates the perceived distortion between both audio signals. In this paper we propose a new metric of low computational complexity called FQI (Fuzzy Quality Index) which is based on Fuzzy Logic reasoning and has been incorporated into the existing PEAQ model to improve its overall performance. Results show that the modified version slightly outperforms PEAQ.
{"title":"A novel fuzzy logic-based metric for audio quality assessment: Objective audio quality assessment","authors":"Luis F. Abanto-Leon, Guillermo Kemper Vasquez, J. Telles","doi":"10.1109/CONATEL.2011.5958657","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958657","url":null,"abstract":"ITU-R BS.1387 states a method for objective assessment of perceived audio quality. This Recommendation, known also as PEAQ (Perceptual Evaluation of Audio Quality) is based on a psychoacoustic model of the human ear and was standardized by the International Telecommunications Union as an alternative to subjective tests, which are expensive and time-consuming processes. PEAQ combines various physiological and psycho-acoustical properties of the human ear to give a measure of the quality difference between a reference audio and a test audio. The reference audio signal could be considered as a distortion-free source, whereas the test signal is a distorted version of the reference, which may have audible artifacts because of compression. The algorithm computes the Model Output Variables (MOVs) which are mapped to a single quality measure, Objective Difference Grade (ODG), using a three-layer perceptron artificial neural network. The ODG estimates the perceived distortion between both audio signals. In this paper we propose a new metric of low computational complexity called FQI (Fuzzy Quality Index) which is based on Fuzzy Logic reasoning and has been incorporated into the existing PEAQ model to improve its overall performance. Results show that the modified version slightly outperforms PEAQ.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129050772","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 : 2011-05-17DOI: 10.1109/CONATEL.2011.5958658
H. Zattar, L. Salek, G. Carrijo
Nowadays, Power Line Communication is becoming an attractive solution to deliver broadband services to indoor and outdoor environment because this technology allows the use of the existing infrastructure. The knowledge of the channel characteristics is very important. A perfect real multipath model is very difficult to be found out because depends on cable models and topology but an accuracy approach is fundamental to evaluate the power line communication by the transfer function. Multi conductor Transmission line theory is an accurate tool to model the transfer function of the channel using complex circuit level models that can be represented in terms of cascaded two-port network. Then it is possible to compute a priori and in a deterministic fashion a transfer function of the PLC channel. This paper is based on the chain matrix method and shows the indoor PLC evaluation with regard to network load impedances, branched line length and number of branches.
{"title":"An evaluation of power line communication channel modelling for indoor environment application","authors":"H. Zattar, L. Salek, G. Carrijo","doi":"10.1109/CONATEL.2011.5958658","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958658","url":null,"abstract":"Nowadays, Power Line Communication is becoming an attractive solution to deliver broadband services to indoor and outdoor environment because this technology allows the use of the existing infrastructure. The knowledge of the channel characteristics is very important. A perfect real multipath model is very difficult to be found out because depends on cable models and topology but an accuracy approach is fundamental to evaluate the power line communication by the transfer function. Multi conductor Transmission line theory is an accurate tool to model the transfer function of the channel using complex circuit level models that can be represented in terms of cascaded two-port network. Then it is possible to compute a priori and in a deterministic fashion a transfer function of the PLC channel. This paper is based on the chain matrix method and shows the indoor PLC evaluation with regard to network load impedances, branched line length and number of branches.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130992466","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 : 2011-05-17DOI: 10.1109/CONATEL.2011.5958663
Patricia Castillo Aranibar, D. Segovia-Vargas, A. García-Lampérez, M. Salazar-Palma
This paper presents a microstrip diplexer for multisystem Distributed Antenna System (DAS) solutions, namely for DCS and UMTS systems. A low-pass quasi-elliptic filter with a stub-like structure is used for the 1800 MHz band while a band-pass Chebychev filter with a hairpin line structure is employed for the 2150 MHz band. Both filters are connected to the common port through a T junction. The diplexer layout has been optimized in order to ensure compactness. Good agreement between simulated and measured results has been obtained. The diplexer shows excellent performance in terms of high isolation and low insertion loss. A semi-lumped element model of the diplexer is also presented.
{"title":"Design of a compact diplexer for multisystem DAS solutions","authors":"Patricia Castillo Aranibar, D. Segovia-Vargas, A. García-Lampérez, M. Salazar-Palma","doi":"10.1109/CONATEL.2011.5958663","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958663","url":null,"abstract":"This paper presents a microstrip diplexer for multisystem Distributed Antenna System (DAS) solutions, namely for DCS and UMTS systems. A low-pass quasi-elliptic filter with a stub-like structure is used for the 1800 MHz band while a band-pass Chebychev filter with a hairpin line structure is employed for the 2150 MHz band. Both filters are connected to the common port through a T junction. The diplexer layout has been optimized in order to ensure compactness. Good agreement between simulated and measured results has been obtained. The diplexer shows excellent performance in terms of high isolation and low insertion loss. A semi-lumped element model of the diplexer is also presented.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121864548","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 : 2011-05-17DOI: 10.1109/CONATEL.2011.5958669
C. Peixeiro
A preliminary approach for the analysis and design of patch antennas located over biological tissues is presented. The study is performed in the 2.4 GHz ISM band envisaging body area and personal area network applications. A moment method numerical analysis is used to check the effects of the biological tissues on the patch antenna performance. Both single patches and two element arrays are analyzed. The conclusions obtained can be used as guidelines to conduct a more accurate approach where the complete model of the human body (shape and size) is taken into account.
{"title":"Patch antennas for BAN/PAN applications at 2.45 GHz: A preliminary approach","authors":"C. Peixeiro","doi":"10.1109/CONATEL.2011.5958669","DOIUrl":"https://doi.org/10.1109/CONATEL.2011.5958669","url":null,"abstract":"A preliminary approach for the analysis and design of patch antennas located over biological tissues is presented. The study is performed in the 2.4 GHz ISM band envisaging body area and personal area network applications. A moment method numerical analysis is used to check the effects of the biological tissues on the patch antenna performance. Both single patches and two element arrays are analyzed. The conclusions obtained can be used as guidelines to conduct a more accurate approach where the complete model of the human body (shape and size) is taken into account.","PeriodicalId":197632,"journal":{"name":"CONATEL 2011","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2011-05-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133244530","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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