Esma Kökten, Bahadır Can Çalışkan, S. Karamzadeh, Ece Gelal Soyak
Abstract The last decade has seen multiple research work on the use of LoRaWAN technology in smart agriculture. In open field storage, monitoring is crucial for increasing the logistics efficiency and improving crop quality. As battery maintenance is expensive in such areas, LoRa is a suitable technology that allows for low-power communications. Within the framework of the research, a prototype has been built for tracking goods in open field storage. The battery lifetime has been analysed through calculations and measurements using LoRa communications. Our findings indicate that although sleeping current has the smallest percentage, it has the greatest effect on increasing the battery life, for longer battery life LoRa node must have a low self-discharge battery, and finally, sensors are the main battery depleting factor on the LoRa node.
{"title":"Low-Power Agriculture IoT System with LoRa: Open Field Storage Observation","authors":"Esma Kökten, Bahadır Can Çalışkan, S. Karamzadeh, Ece Gelal Soyak","doi":"10.2478/ecce-2020-0013","DOIUrl":"https://doi.org/10.2478/ecce-2020-0013","url":null,"abstract":"Abstract The last decade has seen multiple research work on the use of LoRaWAN technology in smart agriculture. In open field storage, monitoring is crucial for increasing the logistics efficiency and improving crop quality. As battery maintenance is expensive in such areas, LoRa is a suitable technology that allows for low-power communications. Within the framework of the research, a prototype has been built for tracking goods in open field storage. The battery lifetime has been analysed through calculations and measurements using LoRa communications. Our findings indicate that although sleeping current has the smallest percentage, it has the greatest effect on increasing the battery life, for longer battery life LoRa node must have a low self-discharge battery, and finally, sensors are the main battery depleting factor on the LoRa node.","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"88 - 94"},"PeriodicalIF":0.7,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45205343","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}
A. Aboltins, J. Grizans, D. Pikulins, M. Terauds, M. Zeltins
Abstract During the past decade, attacks by grey seals on fishing nets in the Baltic Sea have caused considerable loss of fish catch and damage to fishing gears. One of the approaches to reduce the number of seal attacks on fishing nets is to use acoustic deterrent devices (ADDs). Unfortunately, most of the commercially available ADDs are not well suited to the deployment in the sea and require considerable additional investments. The objective of the present research is to develop a compact and cost-efficient ADD for deployment in the sea environment. This paper is devoted to the design of acoustic signals for a prototype ADD. Signals from other experimental and commercially available ADDs are studied and compared. Moreover, limitations imposed by the underwater environment, transducers, battery power, and fish hearing are analysed and considered during the development of signal patterns. The results of tests conducted in an artificial reservoir and in the sea are presented.
{"title":"Design of Acoustic Signals for a Seal Deterrent Device","authors":"A. Aboltins, J. Grizans, D. Pikulins, M. Terauds, M. Zeltins","doi":"10.2478/ecce-2020-0011","DOIUrl":"https://doi.org/10.2478/ecce-2020-0011","url":null,"abstract":"Abstract During the past decade, attacks by grey seals on fishing nets in the Baltic Sea have caused considerable loss of fish catch and damage to fishing gears. One of the approaches to reduce the number of seal attacks on fishing nets is to use acoustic deterrent devices (ADDs). Unfortunately, most of the commercially available ADDs are not well suited to the deployment in the sea and require considerable additional investments. The objective of the present research is to develop a compact and cost-efficient ADD for deployment in the sea environment. This paper is devoted to the design of acoustic signals for a prototype ADD. Signals from other experimental and commercially available ADDs are studied and compared. Moreover, limitations imposed by the underwater environment, transducers, battery power, and fish hearing are analysed and considered during the development of signal patterns. The results of tests conducted in an artificial reservoir and in the sea are presented.","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"72 - 77"},"PeriodicalIF":0.7,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42447729","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}
Abstract This study is dedicated to solve manoeuvres making task while working on the station with no marshalling hump. It is part of the project aimed at the development of intelligent safety and optimal control systems of autonomous electric vehicles and transport in general. The main manoeuvres safety depends on the lack of items and other objects on the rails as well as on the position of turnouts. In most cases rails, occupied with other wagons, as well as the wrong position of turnouts are marked with prohibiting red or blue signals of the traffic light. The authors propose an algorithm for the traffic light recognition by using a convolutional neural network (CNN) and traffic light indicator recognition. However, the situation when the locomotive needs to drive on the rails occupied with other wagons, for example, during the manoeuvres on the railway station can also appear. For this purpose, the authors have developed a CNN algorithm for the wagon recognition on the rails.
{"title":"Algorithms for Railway Embedded Control Devices for Safety Manoeuvres","authors":"A. Beinarovica, M. Gorobetz, Ivars Alps","doi":"10.2478/ecce-2020-0014","DOIUrl":"https://doi.org/10.2478/ecce-2020-0014","url":null,"abstract":"Abstract This study is dedicated to solve manoeuvres making task while working on the station with no marshalling hump. It is part of the project aimed at the development of intelligent safety and optimal control systems of autonomous electric vehicles and transport in general. The main manoeuvres safety depends on the lack of items and other objects on the rails as well as on the position of turnouts. In most cases rails, occupied with other wagons, as well as the wrong position of turnouts are marked with prohibiting red or blue signals of the traffic light. The authors propose an algorithm for the traffic light recognition by using a convolutional neural network (CNN) and traffic light indicator recognition. However, the situation when the locomotive needs to drive on the rails occupied with other wagons, for example, during the manoeuvres on the railway station can also appear. For this purpose, the authors have developed a CNN algorithm for the wagon recognition on the rails.","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"95 - 101"},"PeriodicalIF":0.7,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46134350","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}
Abstract In order to accurately estimate wind farm output and subsequently optimise it, a method of wind speed distribution approximation is suggested. The method is based on period-by-period accumulation of wind speed measurements, transforming them into empirical probabilities, and observing the moving approximation to the expected power produced by the wind turbine or entire wind farm. A year is a minimal term during which wind statistics are to be accumulated. The sufficient validity and reliability of the wind speed distribution approximation is supported by controlling root -mean-square deviations and maximal absolute deviations with respect to the moving average of the expected power. The approximation quality can be regulated by adjusting constants defining the requirements to the moving deviations.
{"title":"Wind Speed Distribution Direct Approximation by Accumulative Statistics of Measurements and Root-Mean-Square Deviation Control","authors":"V. Romanuke","doi":"10.2478/ecce-2020-0010","DOIUrl":"https://doi.org/10.2478/ecce-2020-0010","url":null,"abstract":"Abstract In order to accurately estimate wind farm output and subsequently optimise it, a method of wind speed distribution approximation is suggested. The method is based on period-by-period accumulation of wind speed measurements, transforming them into empirical probabilities, and observing the moving approximation to the expected power produced by the wind turbine or entire wind farm. A year is a minimal term during which wind statistics are to be accumulated. The sufficient validity and reliability of the wind speed distribution approximation is supported by controlling root -mean-square deviations and maximal absolute deviations with respect to the moving average of the expected power. The approximation quality can be regulated by adjusting constants defining the requirements to the moving deviations.","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"65 - 71"},"PeriodicalIF":0.7,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44830175","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}
Abstract A novel mechanically tunable waveguide dielectric filter is presented in this paper. The resonant structure of the filter is made of a rectangular waveguide cavity and an H-plane dielectric cylinder cut in half. The resonating frequency of the proposed structure can be significantly changed by moving two split cylinder parts. The coupling matrix synthesis technique is used to create the required bandpass filter. A drawback of the proposed structure is that the tuning process invokes a mismatch between the feeding structure and the filter. To overcome this drawback, the tuning screws between the coupling irises are used. A filter with the proposed geometry has a large frequency tuning range as well as relatively constant passband bandwidth.
{"title":"Effectively Tunable Bandpass Waveguide Filter Based on Incorporation of Coupled Cylindrical Resonators Cut in Half","authors":"K. Kimsis, J. Semenjako, Y. Shestopalov","doi":"10.2478/ecce-2020-0012","DOIUrl":"https://doi.org/10.2478/ecce-2020-0012","url":null,"abstract":"Abstract A novel mechanically tunable waveguide dielectric filter is presented in this paper. The resonant structure of the filter is made of a rectangular waveguide cavity and an H-plane dielectric cylinder cut in half. The resonating frequency of the proposed structure can be significantly changed by moving two split cylinder parts. The coupling matrix synthesis technique is used to create the required bandpass filter. A drawback of the proposed structure is that the tuning process invokes a mismatch between the feeding structure and the filter. To overcome this drawback, the tuning screws between the coupling irises are used. A filter with the proposed geometry has a large frequency tuning range as well as relatively constant passband bandwidth.","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"78 - 87"},"PeriodicalIF":0.7,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48561219","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}
V. Shevchenko, M. Khomenko, I. Kondratenko, O. Husev, B. Pakhaliuk
Abstract The paper is devoted to the comparison of different types and different values of coils for inductive power transfer in the classical circuit. This topic is relevant with the growing demand and interest in wireless chargers and the diversity of inductance coils for wireless power transfer. The main geometric parameters affecting the coil efficiency are determined. For experimental verification the classical scheme for wireless power transfer is used based on a full-bridge inverter. Different coils at different distance between them, lateral misalignment and load resistance changed are tested. It is determined that single-layer coils have better transmit-receive efficiency than double-layer ones, especially with series-series compensation topology. The application of two-layer coils is recommended in case of high input current. The investigated samples have efficiency at the level of industrial standards. The design approach can be used for any level of power and application, including wireless charging of electric vehicle batteries.
{"title":"Experimental Comparison of Designed Inductance Coils for Wireless Power Transfer","authors":"V. Shevchenko, M. Khomenko, I. Kondratenko, O. Husev, B. Pakhaliuk","doi":"10.2478/ecce-2020-0015","DOIUrl":"https://doi.org/10.2478/ecce-2020-0015","url":null,"abstract":"Abstract The paper is devoted to the comparison of different types and different values of coils for inductive power transfer in the classical circuit. This topic is relevant with the growing demand and interest in wireless chargers and the diversity of inductance coils for wireless power transfer. The main geometric parameters affecting the coil efficiency are determined. For experimental verification the classical scheme for wireless power transfer is used based on a full-bridge inverter. Different coils at different distance between them, lateral misalignment and load resistance changed are tested. It is determined that single-layer coils have better transmit-receive efficiency than double-layer ones, especially with series-series compensation topology. The application of two-layer coils is recommended in case of high input current. The investigated samples have efficiency at the level of industrial standards. The design approach can be used for any level of power and application, including wireless charging of electric vehicle batteries.","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"102 - 109"},"PeriodicalIF":0.7,"publicationDate":"2020-12-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46544475","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}
Abstract Meander structures allow reducing the size of the microwave devices while keeping the same operational characteristics. The shape of meander makes a considerable impact on the operation of microwave devices. Therefore, the structure of meander is widely investigated nowadays. The review of different shapes of a meander conductor is presented in this article. Two models with different shape of connecting conductors are designed and discussed in detail. The influence of variation of the length and width of connecting conductors on the electrical parameters of the meander is revealed using the traditional model of meander. Later, the comparison of the traditional model and the model with rectangle-shape peripheral parts of a meander conductor is presented. The increase in the width of connecting conductors from 0.2 mm to 1.0 mm has narrowed the bandwidth by 346 MHz until 2.388 GHz. The increase in the length of connecting conductors to 2.3 mm has allowed moving the stop-band to higher frequencies. The usage of the rectangle-shape connecting conductors slightly reduces the pass-band but allows achieving more stable input impedance.
{"title":"Meander Conductor Shape Influence on the Electrodynamic Parameters of the Meander Structures","authors":"Diana Belova-Plonienė, A. Katkevičius","doi":"10.2478/ecce-2020-0008","DOIUrl":"https://doi.org/10.2478/ecce-2020-0008","url":null,"abstract":"Abstract Meander structures allow reducing the size of the microwave devices while keeping the same operational characteristics. The shape of meander makes a considerable impact on the operation of microwave devices. Therefore, the structure of meander is widely investigated nowadays. The review of different shapes of a meander conductor is presented in this article. Two models with different shape of connecting conductors are designed and discussed in detail. The influence of variation of the length and width of connecting conductors on the electrical parameters of the meander is revealed using the traditional model of meander. Later, the comparison of the traditional model and the model with rectangle-shape peripheral parts of a meander conductor is presented. The increase in the width of connecting conductors from 0.2 mm to 1.0 mm has narrowed the bandwidth by 346 MHz until 2.388 GHz. The increase in the length of connecting conductors to 2.3 mm has allowed moving the stop-band to higher frequencies. The usage of the rectangle-shape connecting conductors slightly reduces the pass-band but allows achieving more stable input impedance.","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"51 - 57"},"PeriodicalIF":0.7,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44681479","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}
Abstract The use of mobile data transfer can significantly increase the range of the remote-controlled operation of multirotor aerial vehicles. The planar antennas of ready-to-use 3G/LTE cellular communication dongles provide a low-cost and lightweight communication solution. In this paper, antenna shadowing caused by a quadcopter frame is experimentally investigated. The communication module is a 3G/LTE “Huawei 3372h” dongle with two planar built-in antennas and a receiver diversity function. The quadcopter frame is a widely used “F450” with Nylon arms and a PCB centre. It has been found that in order to minimize the antenna shadowing effect, planar antennas should be installed at the bottom of the frame, in parallel with the frame, with an air gap not less than the distance to the outer boundary of the reactive Near Field (NF).
{"title":"Experimental Evaluation of the Shadowing of a Planar Antenna Caused by a Quadcopter Frame","authors":"Ibrahim Heydarov, Deniss Brodņevs","doi":"10.2478/ecce-2020-0006","DOIUrl":"https://doi.org/10.2478/ecce-2020-0006","url":null,"abstract":"Abstract The use of mobile data transfer can significantly increase the range of the remote-controlled operation of multirotor aerial vehicles. The planar antennas of ready-to-use 3G/LTE cellular communication dongles provide a low-cost and lightweight communication solution. In this paper, antenna shadowing caused by a quadcopter frame is experimentally investigated. The communication module is a 3G/LTE “Huawei 3372h” dongle with two planar built-in antennas and a receiver diversity function. The quadcopter frame is a widely used “F450” with Nylon arms and a PCB centre. It has been found that in order to minimize the antenna shadowing effect, planar antennas should be installed at the bottom of the frame, in parallel with the frame, with an air gap not less than the distance to the outer boundary of the reactive Near Field (NF).","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"37 - 43"},"PeriodicalIF":0.7,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46963570","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}
Abstract The paper presents experimental diagnostics of the oil-paper insulating system of power transformers using progressive frequency method. The first part of the paper deals with the basic information about diagnostics of power oil transformers. The second part of the paper deals with the use of frequency domain spectroscopy (FDS) for power oil transformers. This method is used in the analysis of insulating condition of power transformer with the system of oil-paper. It was found that the results of these tests are highly influenced by the operating temperature during the experimental measurement. Moisture and conductivity between the insulating transformer paper and oil in an insulating system are highly dependent on the temperature. In the other part, the paper presents experimental results of the diagnostic measurement for a real traction oil transformer at different operating temperatures and states (with oil and without). Finally, the paper presents comparative measurement among several autotransformers with the same power. In experimental measurements, the correlation between the measured values and the operational aspects of the individual oil autotransformers are shown.
{"title":"Frequency Diagnostics of Insulating System of Power Transformers","authors":"M. Gutten, D. Korenčiak, Peter Brnčal, R. Jarina","doi":"10.2478/ecce-2020-0001","DOIUrl":"https://doi.org/10.2478/ecce-2020-0001","url":null,"abstract":"Abstract The paper presents experimental diagnostics of the oil-paper insulating system of power transformers using progressive frequency method. The first part of the paper deals with the basic information about diagnostics of power oil transformers. The second part of the paper deals with the use of frequency domain spectroscopy (FDS) for power oil transformers. This method is used in the analysis of insulating condition of power transformer with the system of oil-paper. It was found that the results of these tests are highly influenced by the operating temperature during the experimental measurement. Moisture and conductivity between the insulating transformer paper and oil in an insulating system are highly dependent on the temperature. In the other part, the paper presents experimental results of the diagnostic measurement for a real traction oil transformer at different operating temperatures and states (with oil and without). Finally, the paper presents comparative measurement among several autotransformers with the same power. In experimental measurements, the correlation between the measured values and the operational aspects of the individual oil autotransformers are shown.","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"1 - 7"},"PeriodicalIF":0.7,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48054471","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}
Jurijs Fedotovs, I. Bunina, A. Zhiravetska, Svetlava Andrianova
Abstract The accumulators utilized in electric transport differ from those of other applications. Their main features are high capacity, minimum size and weight, and reasonable price. There is extensive research worldwide to improve the battery technology. The aim of the research is to create a mathematical model of an electric vehicle that can capture the vehicle speed curve as a data input to generate the consumed and recovered battery current, which can allow the battery parameters to be analysed and conclude whether the vehicle can perform the trip around the city route with the selected battery parameters. This model serves as a tool to simplify and speed up the necessary calculations and to examine individual sections of the route and their impact on the battery. To complete this task, a simplified electric transport mathematical model gives an opportunity to check if the selected battery can be used in the electrical public transport of the city. The input parameters of the model are the parameters of electrical transport. Simulation of the most popular types of batteries has been performed for two routes of buses in Jelgava in order to determine whether the chosen batteries can provide the necessary bus movement. The mathematical model has been developed in the MATLAB/Simulink software. A GPS mobile application SpeedTracker has been used for data logging.
{"title":"Testing of Technical Indicators of Accumulators by Means of Complex Computer Model of EV","authors":"Jurijs Fedotovs, I. Bunina, A. Zhiravetska, Svetlava Andrianova","doi":"10.2478/ecce-2020-0002","DOIUrl":"https://doi.org/10.2478/ecce-2020-0002","url":null,"abstract":"Abstract The accumulators utilized in electric transport differ from those of other applications. Their main features are high capacity, minimum size and weight, and reasonable price. There is extensive research worldwide to improve the battery technology. The aim of the research is to create a mathematical model of an electric vehicle that can capture the vehicle speed curve as a data input to generate the consumed and recovered battery current, which can allow the battery parameters to be analysed and conclude whether the vehicle can perform the trip around the city route with the selected battery parameters. This model serves as a tool to simplify and speed up the necessary calculations and to examine individual sections of the route and their impact on the battery. To complete this task, a simplified electric transport mathematical model gives an opportunity to check if the selected battery can be used in the electrical public transport of the city. The input parameters of the model are the parameters of electrical transport. Simulation of the most popular types of batteries has been performed for two routes of buses in Jelgava in order to determine whether the chosen batteries can provide the necessary bus movement. The mathematical model has been developed in the MATLAB/Simulink software. A GPS mobile application SpeedTracker has been used for data logging.","PeriodicalId":42365,"journal":{"name":"Electrical Control and Communication Engineering","volume":"16 1","pages":"8 - 14"},"PeriodicalIF":0.7,"publicationDate":"2020-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48812042","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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