Pub Date : 2021-10-12DOI: 10.1109/ETCM53643.2021.9590687
J. Aller, J. Restrepo, J. Viola
In this paper, a method is proposed to develop the Voltage Behind Reactance (VBR) model of the doubly fed induction generator (DFIG) by applying space vectors. Two reference frames are used, one for the stator and the other for the rotor, to maintain the respective ports. This type of model is useful when simulations are to be performed using circuit analysis tools such as ATP-EMTP, Simulink, PSIM or similar. To demonstrate the validity of the VBR model of the DFIG machine, the results obtained by performing this modeling in ATPDraw and Simulink are compared with simple cases where the rotor is short-circuited, including an external impedance or applying voltage sources at different frequencies. The results obtained from the simulations demonstrate the validity of the model and the simplicity of its derivation using the space vector framework.
{"title":"Voltage Behind Reactance Model of the Doubly Fed Induction Generator using Space Vectors","authors":"J. Aller, J. Restrepo, J. Viola","doi":"10.1109/ETCM53643.2021.9590687","DOIUrl":"https://doi.org/10.1109/ETCM53643.2021.9590687","url":null,"abstract":"In this paper, a method is proposed to develop the Voltage Behind Reactance (VBR) model of the doubly fed induction generator (DFIG) by applying space vectors. Two reference frames are used, one for the stator and the other for the rotor, to maintain the respective ports. This type of model is useful when simulations are to be performed using circuit analysis tools such as ATP-EMTP, Simulink, PSIM or similar. To demonstrate the validity of the VBR model of the DFIG machine, the results obtained by performing this modeling in ATPDraw and Simulink are compared with simple cases where the rotor is short-circuited, including an external impedance or applying voltage sources at different frequencies. The results obtained from the simulations demonstrate the validity of the model and the simplicity of its derivation using the space vector framework.","PeriodicalId":438567,"journal":{"name":"2021 IEEE Fifth Ecuador Technical Chapters Meeting (ETCM)","volume":"72 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114950763","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 : 2021-10-12DOI: 10.1109/ETCM53643.2021.9590760
Greta Navas, E. Sorrentino, E. Orea
This article describes interesting findings which were observed during the study for setting the out-of-step blocking functions of distance relays at Venezuelan 765kV system. An analysis of apparent impedances for different contingencies allowed the determination of locations where this function is necessary. For a given contingency, the apparent impedance is initially near of distance zones for some relay locations, and later for other relay locations. For a given location, the apparent impedances during power swings caused by diverse contingencies are different. That is, a unique location for the electrical center of the system does not exist. Consequently, some relays need the out-of-step blocking functions for some contingencies, other relays for other contingencies, and there are locations where this function is not necessary. The trajectories of apparent impedances tend to be almost horizontal in many cases, but there are some cases where the trajectory is almost vertical in the R-X plane.
{"title":"Analysis of Out-of-Step Blocking Functions of Distance Relays at Venezuelan 765kV System","authors":"Greta Navas, E. Sorrentino, E. Orea","doi":"10.1109/ETCM53643.2021.9590760","DOIUrl":"https://doi.org/10.1109/ETCM53643.2021.9590760","url":null,"abstract":"This article describes interesting findings which were observed during the study for setting the out-of-step blocking functions of distance relays at Venezuelan 765kV system. An analysis of apparent impedances for different contingencies allowed the determination of locations where this function is necessary. For a given contingency, the apparent impedance is initially near of distance zones for some relay locations, and later for other relay locations. For a given location, the apparent impedances during power swings caused by diverse contingencies are different. That is, a unique location for the electrical center of the system does not exist. Consequently, some relays need the out-of-step blocking functions for some contingencies, other relays for other contingencies, and there are locations where this function is not necessary. The trajectories of apparent impedances tend to be almost horizontal in many cases, but there are some cases where the trajectory is almost vertical in the R-X plane.","PeriodicalId":438567,"journal":{"name":"2021 IEEE Fifth Ecuador Technical Chapters Meeting (ETCM)","volume":"6 5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"117018517","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 : 2021-10-12DOI: 10.1109/ETCM53643.2021.9590762
Luis A. Paredes, M. Molina, Marcelo Pozo, B. Serrano
The microgrid (MG) has emerged as part of the technological transition to smart grids. The MG can operate in two modes: connected to a distribution network or in an isolated stand-alone way. When the transition to island mode occurs, the M G must operate in a stable, reliable, and resilient way. In this context, the distributed energy resources (DERs) that are part of the M G must respond optimally to guarantee dynamic voltage stability (DVS) and to improve operational resilience. Under resilient contingency conditions, the voltage stability and reactive power control of the MG is severely compromised. Therefore, even though DERs based on smart inverters operate according to the low-voltage ride-through (L VRT) requirements stated at the IEEE Standard 1547–2018, it is not enough to supply the reactive power deficit. Thus, this paper aims to include FACTS (flexible ac transmission systems) type compensation devices, particularly a static var compensator (SVC) that operates in coordination with DERs of the MG. The results obtained are satisfactory, and it is shown that the smart inverters used for the DERs and the SVC device operating with a coordinated control strategy improved the DVS, allowing the control of the reactive power supply and granting an adequate level of operational resilience in the isolated MG.
{"title":"Improvement of Dynamic Voltage Stability in a Resilient Microgrid based on Smart Inverters & SVC","authors":"Luis A. Paredes, M. Molina, Marcelo Pozo, B. Serrano","doi":"10.1109/ETCM53643.2021.9590762","DOIUrl":"https://doi.org/10.1109/ETCM53643.2021.9590762","url":null,"abstract":"The microgrid (MG) has emerged as part of the technological transition to smart grids. The MG can operate in two modes: connected to a distribution network or in an isolated stand-alone way. When the transition to island mode occurs, the M G must operate in a stable, reliable, and resilient way. In this context, the distributed energy resources (DERs) that are part of the M G must respond optimally to guarantee dynamic voltage stability (DVS) and to improve operational resilience. Under resilient contingency conditions, the voltage stability and reactive power control of the MG is severely compromised. Therefore, even though DERs based on smart inverters operate according to the low-voltage ride-through (L VRT) requirements stated at the IEEE Standard 1547–2018, it is not enough to supply the reactive power deficit. Thus, this paper aims to include FACTS (flexible ac transmission systems) type compensation devices, particularly a static var compensator (SVC) that operates in coordination with DERs of the MG. The results obtained are satisfactory, and it is shown that the smart inverters used for the DERs and the SVC device operating with a coordinated control strategy improved the DVS, allowing the control of the reactive power supply and granting an adequate level of operational resilience in the isolated MG.","PeriodicalId":438567,"journal":{"name":"2021 IEEE Fifth Ecuador Technical Chapters Meeting (ETCM)","volume":"56 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130142138","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 : 2021-10-12DOI: 10.1109/ETCM53643.2021.9590655
Kevin Vicuña, Cristhopher Mosquera, Mateo Rendón, Ariana Musello, M. Lanuzza, L. Prócel, R. Taco, L. Trojman
This paper presents the design and post-layout simulation of a two-stage operational amplifier (opamp) with Miller compensation, using a third stage that acts as output buffer to drive large loads. The TSMC 0.18μm PDK was used for the design, simulation and implementation in Cadence Virtuoso. The opamp exhibits 20μW power consumption with a 1-V rail-to-rail supply. Post layout simulation shows a unity gain bandwidth (UGBW) of 69.18 MHz $(A_{v}=mathbf{49.63dB})$ with a phase margin (PM) larger than 86° and a Slew rate of $19.87mumathrm{V}_mathrm{s}$; making our design suitable for small and large signal applications.
{"title":"A 180 nm Low-Cost Operational Amplifier for IoT Applications","authors":"Kevin Vicuña, Cristhopher Mosquera, Mateo Rendón, Ariana Musello, M. Lanuzza, L. Prócel, R. Taco, L. Trojman","doi":"10.1109/ETCM53643.2021.9590655","DOIUrl":"https://doi.org/10.1109/ETCM53643.2021.9590655","url":null,"abstract":"This paper presents the design and post-layout simulation of a two-stage operational amplifier (opamp) with Miller compensation, using a third stage that acts as output buffer to drive large loads. The TSMC 0.18μm PDK was used for the design, simulation and implementation in Cadence Virtuoso. The opamp exhibits 20μW power consumption with a 1-V rail-to-rail supply. Post layout simulation shows a unity gain bandwidth (UGBW) of 69.18 MHz $(A_{v}=mathbf{49.63dB})$ with a phase margin (PM) larger than 86° and a Slew rate of $19.87mumathrm{V}_mathrm{s}$; making our design suitable for small and large signal applications.","PeriodicalId":438567,"journal":{"name":"2021 IEEE Fifth Ecuador Technical Chapters Meeting (ETCM)","volume":"21 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125481387","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 : 2021-10-12DOI: 10.1109/ETCM53643.2021.9590641
Guillermo Rodriguez, Hover Torres, M. Fajardo, Jonathan Medina
Exploring the behavior and impact that the Covid-19 pandemic is causing on the supply of hospital services in the main cities of Ecuador is the urgent aspiration of national and local authorities and society in general. Therefore, this work evaluates the distribution and area of influence of hospitals suitable for care of critically ill patients. For the study, advanced computational techniques were used, the data were obtained from Open Street Maps OSM and the Ministry of Public Health. In this work, it is possible to chain the process of extraction of statistical data of fatality product of Covid-19, the geolocation and distribution of the Health Centers (HC) of Quito, Guayaquiñl and Cuenca. Then, based on this information, it is verified how the hospital supply capacity and the balanced distribution of HC affect the number of deaths caused by the pandemic. Concluding that Guayaquil has the highest number of deaths and has the lowest rate of HC and a more unequal distribution; on the other hand, Cuenca has the lowest number of deaths and the highest HC rate with a more balanced distribution of HC.
{"title":"Covid-19 in Ecuador: Radiography of Hospital Distribution Using Data Science","authors":"Guillermo Rodriguez, Hover Torres, M. Fajardo, Jonathan Medina","doi":"10.1109/ETCM53643.2021.9590641","DOIUrl":"https://doi.org/10.1109/ETCM53643.2021.9590641","url":null,"abstract":"Exploring the behavior and impact that the Covid-19 pandemic is causing on the supply of hospital services in the main cities of Ecuador is the urgent aspiration of national and local authorities and society in general. Therefore, this work evaluates the distribution and area of influence of hospitals suitable for care of critically ill patients. For the study, advanced computational techniques were used, the data were obtained from Open Street Maps OSM and the Ministry of Public Health. In this work, it is possible to chain the process of extraction of statistical data of fatality product of Covid-19, the geolocation and distribution of the Health Centers (HC) of Quito, Guayaquiñl and Cuenca. Then, based on this information, it is verified how the hospital supply capacity and the balanced distribution of HC affect the number of deaths caused by the pandemic. Concluding that Guayaquil has the highest number of deaths and has the lowest rate of HC and a more unequal distribution; on the other hand, Cuenca has the lowest number of deaths and the highest HC rate with a more balanced distribution of HC.","PeriodicalId":438567,"journal":{"name":"2021 IEEE Fifth Ecuador Technical Chapters Meeting (ETCM)","volume":"152 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"121519571","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 : 2021-10-12DOI: 10.1109/ETCM53643.2021.9590665
Diego Arias-Cazco, Angel Vaca Peñafiel
This work establishes a solution to assess the bus loadability limits by using a multi-objective optimization evaluation of active and reactive power. As a part of the methodology, it is also considered the operating limits of the Electric Power Systems (EPS), such as the generation capacity, reactive power reserves, active power capacity, restrictions of the transmission system, and bus voltages. The Pareto front is obtained from the multi-objective problem, represented by the bus's PQ curve under analysis. The multiobjective optimization problem is solved by combining two functions and the limits of active and reactive power margins at the same bus. Complementary, the methodology is applied to the IEEE 14 Bus system to evaluate its applicability, analyze the results, and evidence its strengths. Thus, a reliable method is provided to assess the bus's power margins, the system's security in electrical networks, and the EPS loadability limits.
{"title":"Multi-objective Optimization of Active and Reactive Power to assess Bus Loadability Limit","authors":"Diego Arias-Cazco, Angel Vaca Peñafiel","doi":"10.1109/ETCM53643.2021.9590665","DOIUrl":"https://doi.org/10.1109/ETCM53643.2021.9590665","url":null,"abstract":"This work establishes a solution to assess the bus loadability limits by using a multi-objective optimization evaluation of active and reactive power. As a part of the methodology, it is also considered the operating limits of the Electric Power Systems (EPS), such as the generation capacity, reactive power reserves, active power capacity, restrictions of the transmission system, and bus voltages. The Pareto front is obtained from the multi-objective problem, represented by the bus's PQ curve under analysis. The multiobjective optimization problem is solved by combining two functions and the limits of active and reactive power margins at the same bus. Complementary, the methodology is applied to the IEEE 14 Bus system to evaluate its applicability, analyze the results, and evidence its strengths. Thus, a reliable method is provided to assess the bus's power margins, the system's security in electrical networks, and the EPS loadability limits.","PeriodicalId":438567,"journal":{"name":"2021 IEEE Fifth Ecuador Technical Chapters Meeting (ETCM)","volume":"20 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114198958","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 : 2021-10-12DOI: 10.1109/ETCM53643.2021.9590636
S. Cedillo, L. Timbe, E. Sánchez-Cordero, E. Samaniego, K. Narea, A. Alvarado
One-dimensional hydrodynamic models (HM) are widely used in the hydraulic modeling of rivers and channels. The result obtained with this type of model depends largely on correct estimation the roughness parameter. The value of the roughness parameter obtained through a HM calibration process differs from the one measured in the field. Hence, the objective of this research is focused on identifying the difference between physical and effective roughness for different morphologies present in Mountain Rivers. Physical roughness was indirectly measured with field data and Manning equation, while Effective roughness was found through GLUE experiments using water depth as validation data in one dimensional models in HEC RAS. Physical and effective roughness coefficients have shown differences depending on the morphology. In Cascade and Step-pool the physical roughness is higher than effective roughness, while in Plane-bed effective roughness is higher than physical roughness. The differences are attributed to the deviations that occur between the real conditions and the flow idealizations in an 1D - HD model. For any modelling application is important to research roughness values used previously and avoid formulations or tables which are based on field measurements.
{"title":"Differences Between Effective and Physical Roughness Parameter- A Headwater Mountain River Experiment","authors":"S. Cedillo, L. Timbe, E. Sánchez-Cordero, E. Samaniego, K. Narea, A. Alvarado","doi":"10.1109/ETCM53643.2021.9590636","DOIUrl":"https://doi.org/10.1109/ETCM53643.2021.9590636","url":null,"abstract":"One-dimensional hydrodynamic models (HM) are widely used in the hydraulic modeling of rivers and channels. The result obtained with this type of model depends largely on correct estimation the roughness parameter. The value of the roughness parameter obtained through a HM calibration process differs from the one measured in the field. Hence, the objective of this research is focused on identifying the difference between physical and effective roughness for different morphologies present in Mountain Rivers. Physical roughness was indirectly measured with field data and Manning equation, while Effective roughness was found through GLUE experiments using water depth as validation data in one dimensional models in HEC RAS. Physical and effective roughness coefficients have shown differences depending on the morphology. In Cascade and Step-pool the physical roughness is higher than effective roughness, while in Plane-bed effective roughness is higher than physical roughness. The differences are attributed to the deviations that occur between the real conditions and the flow idealizations in an 1D - HD model. For any modelling application is important to research roughness values used previously and avoid formulations or tables which are based on field measurements.","PeriodicalId":438567,"journal":{"name":"2021 IEEE Fifth Ecuador Technical Chapters Meeting (ETCM)","volume":"357 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115859774","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 : 2021-10-12DOI: 10.1109/ETCM53643.2021.9590672
S. Shinde, Juan Carlos Martinez-Ovando
Disease detection is quite a difficult task and it requires medical training and experience. When it comes to heart disease diagnostics, it gets even more complex due to the additional specialization and expertise required. One of the common ways for detecting heart diseases used by heart specialists is by listening to the patient's heartbeat via a stethoscope and interpreting the sound. In this paper, we describe how we can use deep learning techniques to detect heart diseases in patients by analyzing audio recording or real time streaming of heartbeats to predict whether the patient is healthy or sick. The deep neural network model developed is a hybrid model as it combines the innate characteristics of convolutional and recurrent neural network models, which helped achieve higher accuracy in the prediction results as compared to current published results. The dataset used for training the model is a combination of two separate data science competition datasets. We used data augmentation techniques on this combined dataset to increase its size and diversity. When we tested the final model, it showed a significantly better performance as compared to the state of the art.
{"title":"Heart Disease Detection with Deep Learning Using a Combination of Multiple Input Sources","authors":"S. Shinde, Juan Carlos Martinez-Ovando","doi":"10.1109/ETCM53643.2021.9590672","DOIUrl":"https://doi.org/10.1109/ETCM53643.2021.9590672","url":null,"abstract":"Disease detection is quite a difficult task and it requires medical training and experience. When it comes to heart disease diagnostics, it gets even more complex due to the additional specialization and expertise required. One of the common ways for detecting heart diseases used by heart specialists is by listening to the patient's heartbeat via a stethoscope and interpreting the sound. In this paper, we describe how we can use deep learning techniques to detect heart diseases in patients by analyzing audio recording or real time streaming of heartbeats to predict whether the patient is healthy or sick. The deep neural network model developed is a hybrid model as it combines the innate characteristics of convolutional and recurrent neural network models, which helped achieve higher accuracy in the prediction results as compared to current published results. The dataset used for training the model is a combination of two separate data science competition datasets. We used data augmentation techniques on this combined dataset to increase its size and diversity. When we tested the final model, it showed a significantly better performance as compared to the state of the art.","PeriodicalId":438567,"journal":{"name":"2021 IEEE Fifth Ecuador Technical Chapters Meeting (ETCM)","volume":"207 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123498340","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 : 2021-10-12DOI: 10.1109/ETCM53643.2021.9590793
D. Gomez, Alexandra Bermeo, Daniela Prado, Priscila Cedillo
Nowadays, older adults need to actively participate in society's processes and activities without being isolated, abandoned, discriminated against, or placed in a vulnerable situation. The COVID-19 pandemic shows a gradual increase in risk with age, which has led to confinement for this population sector. With these considerations, it is advisable to educate older adults on the general measures to prevent COVID-19, to adapt to today's society and decrease the likelihood of contagion. In this sense, a learning artifact about COVID-19 prevention measures, through a methodology for creating learning capsules for older adults designed to educate from home through mobile devices. Moreover, for evaluating the perceptions of the users about the proposed learning artifact, a case study where older people participated was proposed; here, the Technology Acceptance Model (TAM) was used.
{"title":"Microlearning Method to Building Learning Capsules for Older Adults: A Case Study for COVID-19 Prevention at Home","authors":"D. Gomez, Alexandra Bermeo, Daniela Prado, Priscila Cedillo","doi":"10.1109/ETCM53643.2021.9590793","DOIUrl":"https://doi.org/10.1109/ETCM53643.2021.9590793","url":null,"abstract":"Nowadays, older adults need to actively participate in society's processes and activities without being isolated, abandoned, discriminated against, or placed in a vulnerable situation. The COVID-19 pandemic shows a gradual increase in risk with age, which has led to confinement for this population sector. With these considerations, it is advisable to educate older adults on the general measures to prevent COVID-19, to adapt to today's society and decrease the likelihood of contagion. In this sense, a learning artifact about COVID-19 prevention measures, through a methodology for creating learning capsules for older adults designed to educate from home through mobile devices. Moreover, for evaluating the perceptions of the users about the proposed learning artifact, a case study where older people participated was proposed; here, the Technology Acceptance Model (TAM) was used.","PeriodicalId":438567,"journal":{"name":"2021 IEEE Fifth Ecuador Technical Chapters Meeting (ETCM)","volume":"47 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2021-10-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124221495","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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