Wesley Emile Dharmalingum, J. Padayachee, G. Bright
This paper presents the design and analysis of a novel five degrees-of- freedom (DOF) parallel kinematic manipulator (PKM) for part-handling, sorting, general positioning, and robotic machining applications. The 2- R(Pa-IQ)RR, R(Pa-IQ)R manipulator has two rotational DOFs, one parasitic rotation, and three translational DOFs. In comparison with other 5- and 6- DOF PKMs, this PKM possesses three pairs of coplanar legs that contain nested kinematic chains, and it makes exclusive use of revolute and prismatic joints. The inverse kinematic analysis is a novel extension of the geometric (vector) method with the analysis of inner and outer kinematic chains. The forward kinematic analysis was solved using the Newton Raphson (NR) method. The results of the forward and inverse kinematic analyses were validated with SolidWorks ® and MATLAB ® simulations.
{"title":"SYNTHESIS OF A NOVEL FIVE-DEGREES–OF-FREEDOM PARALLEL KINEMATIC MANIPULATOR","authors":"Wesley Emile Dharmalingum, J. Padayachee, G. Bright","doi":"10.7166/32-1-2382","DOIUrl":"https://doi.org/10.7166/32-1-2382","url":null,"abstract":"This paper presents the design and analysis of a novel five degrees-of- freedom (DOF) parallel kinematic manipulator (PKM) for part-handling, sorting, general positioning, and robotic machining applications. The 2- R(Pa-IQ)RR, R(Pa-IQ)R manipulator has two rotational DOFs, one parasitic rotation, and three translational DOFs. In comparison with other 5- and 6- DOF PKMs, this PKM possesses three pairs of coplanar legs that contain nested kinematic chains, and it makes exclusive use of revolute and prismatic joints. The inverse kinematic analysis is a novel extension of the geometric (vector) method with the analysis of inner and outer kinematic chains. The forward kinematic analysis was solved using the Newton Raphson (NR) method. The results of the forward and inverse kinematic analyses were validated with SolidWorks ® and MATLAB ® simulations.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45581090","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Many businesses in the additive manufacturing industry have limited equipment capacity. This method of using time-driven activity-based costing in collaboration with digital twinning will be advantageous to optimise their use of time and their capacity. Optimising the use of time is essential to ensure efficient process flow and to waste less time and money. To optimise, we need to analyse system dynamics and model system responses, to enable us to consider various scenarios iteratively. This paper first considers activity-based costing, driven by its most precious resource, time. Standard time is defined as the base parameter by which cost is calculated. Charge-out rates of elements are based on the actual cost of equipment apportioned to activities, based on the time spent using such equipment. The process chain is broken into elements, each of which incurs full cost when started. The value chain develops accordingly, enabling us to predict the actual cost of production. Second, the use of digital twinning to model standard time is considered. Stochastic variation is evident, but standard time can be allocated to each element in the process chain, given a certain confidence level. Together, a cause — effect prediction model can be developed. The model would predict the time that a process chain, consisting of known elements, would take. However, in the event of an occurrence out of the norm, the updated expected time can be predicted. Using the same rates, the new cost can be determined immediately. We propose that the digital twin can predict production cost, based on a statistically measurable stochastic variation of element duration and the time-varying charge-out rate.
{"title":"TIME-DRIVEN ACTIVITY-BASED COSTING RELATED TO DIGITAL TWINNING IN ADDITIVE MANUFACTURING","authors":"Alistair R. Anderson, A. F. Van Der Merwe","doi":"10.7166/32-1-2271","DOIUrl":"https://doi.org/10.7166/32-1-2271","url":null,"abstract":"Many businesses in the additive manufacturing industry have limited equipment capacity. This method of using time-driven activity-based costing in collaboration with digital twinning will be advantageous to optimise their use of time and their capacity. Optimising the use of time is essential to ensure efficient process flow and to waste less time and money. To optimise, we need to analyse system dynamics and model system responses, to enable us to consider various scenarios iteratively. This paper first considers activity-based costing, driven by its most precious resource, time. Standard time is defined as the base parameter by which cost is calculated. Charge-out rates of elements are based on the actual cost of equipment apportioned to activities, based on the time spent using such equipment. The process chain is broken into elements, each of which incurs full cost when started. The value chain develops accordingly, enabling us to predict the actual cost of production. Second, the use of digital twinning to model standard time is considered. Stochastic variation is evident, but standard time can be allocated to each element in the process chain, given a certain confidence level. Together, a cause — effect prediction model can be developed. The model would predict the time that a process chain, consisting of known elements, would take. However, in the event of an occurrence out of the norm, the updated expected time can be predicted. Using the same rates, the new cost can be determined immediately. We propose that the digital twin can predict production cost, based on a statistically measurable stochastic variation of element duration and the time-varying charge-out rate.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49156199","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Advanced robotic systems are an Industry 4.0 enabler in smart factories. Industrial robotic manipulators require an end-effector to perform tasks. The purpose of this study was to research and develop a reconfigurable robotic end-effector for machining and part handling. The device eliminates the need for separate robots to perform part handling and machining operations. A reconfigurable, dual-purpose design eliminates lengthy end-effector changes. The paper presents the mechanical conceptualisation, detailed design, manufacturing, and testing of the end- effector and spindle system. The concept uses a flexible, cable-driven gripper system in conjunction with a compact, lightweight milling system that is capable of machining non-ferrous metals. The results demonstrate the versatility and high compliance of the gripper. An experimental study revealed the influence that reconfigurability has on the spindle dynamics. The dynamic response of the gripping system was also experimentally examined during machining to evaluate the practicality of a dual-purpose design. Experimentally developed stability lobe diagrams are presented, which characterise the stable operating parameters of the machining system.
{"title":"DEVELOPMENT AND ANALYSIS OF RECONFIGURABLE ROBOTIC END-EFFECTOR FOR MACHINING AND PART HANDLING","authors":"C.E. Reddy, J. Padayachee, G. Bright","doi":"10.7166/32-1-2293","DOIUrl":"https://doi.org/10.7166/32-1-2293","url":null,"abstract":"Advanced robotic systems are an Industry 4.0 enabler in smart factories. Industrial robotic manipulators require an end-effector to perform tasks. The purpose of this study was to research and develop a reconfigurable robotic end-effector for machining and part handling. The device eliminates the need for separate robots to perform part handling and machining operations. A reconfigurable, dual-purpose design eliminates lengthy end-effector changes. The paper presents the mechanical conceptualisation, detailed design, manufacturing, and testing of the end- effector and spindle system. The concept uses a flexible, cable-driven gripper system in conjunction with a compact, lightweight milling system that is capable of machining non-ferrous metals. The results demonstrate the versatility and high compliance of the gripper. An experimental study revealed the influence that reconfigurability has on the spindle dynamics. The dynamic response of the gripping system was also experimentally examined during machining to evaluate the practicality of a dual-purpose design. Experimentally developed stability lobe diagrams are presented, which characterise the stable operating parameters of the machining system.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46093188","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Effective knowledge transfer is essential in obtaining a competitive advantage. In a project environment, knowledge transfer occurs across different boundaries and involves different stakeholders — a topic much neglected in the literature. This paper explores the processes at play when knowledge is transferred across different boundaries, and then focuses on the role played by the document management system in a project management office. Results from focus group workshops and interviews indicate that the project management office plays a vital role in ensuring effective knowledge transfer, and that the roles differ at different boundaries. In the mining case study, the document management system plays a key role in knowledge transfer.
{"title":"KNOWLEDGE TRANSFER ACROSS DIFFERENT BOUNDARIES IN A PROJECT ENVIRONMENT: A CASE STUDY OF A BOTSWANA MINING ORGANISATION","authors":"Abel Jhamba, H. Steyn","doi":"10.7166/32-1-2326","DOIUrl":"https://doi.org/10.7166/32-1-2326","url":null,"abstract":"Effective knowledge transfer is essential in obtaining a competitive advantage. In a project environment, knowledge transfer occurs across different boundaries and involves different stakeholders — a topic much neglected in the literature. This paper explores the processes at play when knowledge is transferred across different boundaries, and then focuses on the role played by the document management system in a project management office. Results from focus group workshops and interviews indicate that the project management office plays a vital role in ensuring effective knowledge transfer, and that the roles differ at different boundaries. In the mining case study, the document management system plays a key role in knowledge transfer.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45557314","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The success rate of outsourcing in South Africa is fairly low. Companies that make the incorrect decision to outsource maintenance place themselves at risk of poor maintenance performance, a high operational cost of maintenance, and substantial costs to redevelop internal maintenance capabilities. The identification of the factors applicable to the decision to outsource maintenance can form the basis of a decision framework or model, and has the potential to improve the quality of decision-making in maintenance management. This paper discusses the results of a survey that was carried out to determine the main decision factors that maintenance and asset managers could use when they consider outsourcing some maintenance work. Most of the 62 respondents were from the oil and energy sector or the chemicals sector of South African industry. The main decision factors were identified as contractor experience, the availability of a suitable contractor, and the scarcity of skills or employees. The findings of this survey are useful for maintenance and asset managers to decide whether or not to outsource an activity, and to rank potential contractors.
{"title":"FACTORS THAT INFLUENCE THE DECISION TO OUTSOURCE MAINTENANCE IN THE PROCESSING INDUSTRY","authors":"Darryl James Summers, J. Visser","doi":"10.7166/32-1-2127","DOIUrl":"https://doi.org/10.7166/32-1-2127","url":null,"abstract":"The success rate of outsourcing in South Africa is fairly low. Companies that make the incorrect decision to outsource maintenance place themselves at risk of poor maintenance performance, a high operational cost of maintenance, and substantial costs to redevelop internal maintenance capabilities. The identification of the factors applicable to the decision to outsource maintenance can form the basis of a decision framework or model, and has the potential to improve the quality of decision-making in maintenance management. This paper discusses the results of a survey that was carried out to determine the main decision factors that maintenance and asset managers could use when they consider outsourcing some maintenance work. Most of the 62 respondents were from the oil and energy sector or the chemicals sector of South African industry. The main decision factors were identified as contractor experience, the availability of a suitable contractor, and the scarcity of skills or employees. The findings of this survey are useful for maintenance and asset managers to decide whether or not to outsource an activity, and to rank potential contractors.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46107452","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
A company embracing an agile strategy to win business must increase its agility and that of its strategic suppliers. Segmentation is an important tool for selecting suppliers that can be developed. This paper addresses the challenge of selecting suppliers in order to develop their agility. A novel segmentation of strategic suppliers is done on the dimensions of agility capability and business excellence. The cascaded fuzzy inference system is the tool used to assess the dimensions of agility capability and business excellence and to construct a segmentation matrix. The strategic segmentation matrix helps to identify suppliers that the company can develop.
{"title":"A FUZZY INFERENCE APPROACH TO SUPPLIER SEGMENTATION FOR STRATEGIC DEVELOPMENT","authors":"G. Rajesh, R. Raju","doi":"10.7166/32-1-2286","DOIUrl":"https://doi.org/10.7166/32-1-2286","url":null,"abstract":"A company embracing an agile strategy to win business must increase its agility and that of its strategic suppliers. Segmentation is an important tool for selecting suppliers that can be developed. This paper addresses the challenge of selecting suppliers in order to develop their agility. A novel segmentation of strategic suppliers is done on the dimensions of agility capability and business excellence. The cascaded fuzzy inference system is the tool used to assess the dimensions of agility capability and business excellence and to construct a segmentation matrix. The strategic segmentation matrix helps to identify suppliers that the company can develop.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41755524","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
To achieve sustainable growth and maintain competitive advantages, many companies consider the sustainability of society and the environment, and adopt the business excellence (BE) framework of quality awards to promote total quality management (TQM) activities. This study used the Malcolm Baldrige National Quality Award’s (MBNQA) business excellence evaluation standard as the main body, supplemented by the Dow Jones Sustainability Indexes (DJSI). It proposed scoring criteria for the sustainable business excellence model, and discussed the degree of cause and correlation between evaluation criteria. The key factors were explored to provide companies with a reference for the pursuit of sustainable business excellence.
{"title":"DEVELOPING A SUSTAINABLE BUSINESS EXCELLENCE MODEL AND DISCUSSING KEY FACTORS","authors":"Ping Fan, Wei-Lun Chang","doi":"10.7166/32-1-2397","DOIUrl":"https://doi.org/10.7166/32-1-2397","url":null,"abstract":"To achieve sustainable growth and maintain competitive advantages, many companies consider the sustainability of society and the environment, and adopt the business excellence (BE) framework of quality awards to promote total quality management (TQM) activities. This study used the Malcolm Baldrige National Quality Award’s (MBNQA) business excellence evaluation standard as the main body, supplemented by the Dow Jones Sustainability Indexes (DJSI). It proposed scoring criteria for the sustainable business excellence model, and discussed the degree of cause and correlation between evaluation criteria. The key factors were explored to provide companies with a reference for the pursuit of sustainable business excellence.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":" ","pages":""},"PeriodicalIF":0.5,"publicationDate":"2021-05-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49187997","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Rodrigo de Souza, O. Quelhas, G. Marchisotti, J. Neto, R. Anholon, C. A. Marinho
Industry 4.0 has been discussed in the scientific community since its inception in 2011. Discussions have focused on characterising what Industry 4.0 is. This industry will increasingly require professionals to perform complex and indirect tasks, such as working together with machines in their daily work. This article aims to analyse the skills and competencies required by Industry 4.0, and to compare them with the scope of production engineering disciplines in six Brazilian universities. As a methodological option, the study is classified as exploratory, bibliographic, and qualitative. It is established that the current syllabus of production engineering courses of Brazilian universities needs to be improved, seeking alignment with the skills and competencies required by Industry 4.0. Although the Industry 4.0 theme is being discussed in the scientific field in Brazilian universities, it is not yet possible to identify any key actions taken to adjust and improve production engineering courses.
{"title":"PRODUCTION ENGINEERING CURRICULUM IN INDUSTRY 4.0 IN A BRAZILIAN CONTEXT","authors":"Rodrigo de Souza, O. Quelhas, G. Marchisotti, J. Neto, R. Anholon, C. A. Marinho","doi":"10.7166/31-4-2033","DOIUrl":"https://doi.org/10.7166/31-4-2033","url":null,"abstract":"Industry 4.0 has been discussed in the scientific community since its inception in 2011. Discussions have focused on characterising what Industry 4.0 is. This industry will increasingly require professionals to perform complex and indirect tasks, such as working together with machines in their daily work. This article aims to analyse the skills and competencies required by Industry 4.0, and to compare them with the scope of production engineering disciplines in six Brazilian universities. As a methodological option, the study is classified as exploratory, bibliographic, and qualitative. It is established that the current syllabus of production engineering courses of Brazilian universities needs to be improved, seeking alignment with the skills and competencies required by Industry 4.0. Although the Industry 4.0 theme is being discussed in the scientific field in Brazilian universities, it is not yet possible to identify any key actions taken to adjust and improve production engineering courses.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":"31 1","pages":"136-150"},"PeriodicalIF":0.5,"publicationDate":"2020-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42044462","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
The evolution of continuous improvement methodologies is evident in the formalisation of activities, their spread across disciplines, and the formation of hybrid methodologies. This study focuses on hybrid methodology formation, and specifically on lean and value engineering. It is proposed that hybrid methodologies be implemented using interchangeable use, concurrent use, and integrated use models; however, the literature does not provide distinct model definitions nor a formal framework to guide model selection. This study uses a systematic literature review to establish a model selection framework based on distinct model definitions. The aim of this framework is to support implementation and to create a standardised platform for future development, ultimately leading to improved and more sustainable success in implementation.
{"title":"ESTABLISHING A SELECTION FRAMEWORK FOR A LEAN AND VALUE ENGINEERING HYBRID METHODOLOGY","authors":"Nosipho Philisiwe Gumede, T. Hattingh","doi":"10.7166/31-4-2299","DOIUrl":"https://doi.org/10.7166/31-4-2299","url":null,"abstract":"The evolution of continuous improvement methodologies is evident in the formalisation of activities, their spread across disciplines, and the formation of hybrid methodologies. This study focuses on hybrid methodology formation, and specifically on lean and value engineering. It is proposed that hybrid methodologies be implemented using interchangeable use, concurrent use, and integrated use models; however, the literature does not provide distinct model definitions nor a formal framework to guide model selection. This study uses a systematic literature review to establish a model selection framework based on distinct model definitions. The aim of this framework is to support implementation and to create a standardised platform for future development, ultimately leading to improved and more sustainable success in implementation.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":"31 1","pages":"32-45"},"PeriodicalIF":0.5,"publicationDate":"2020-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45266161","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Queueing is a common phenomenon in various stages of manufacturing systems and some other organisations. Queueing usually reduces the time required by managers and manufacturers to complete a desired task. The queueing mathematical theory is a viable tool for analysing a waiting line model. This research presents the implementation of robots at the packaging stage of a virtual manufacturing scenario in which mathematical models were used to describe each stage of the manufacturing process. Some suitable parameters and operating conditions were assumed, and the Newton-Raphson iteration formula was implemented for numerical analysis of the models. Simulation was carried out to achieve optimal values that could yield efficient productivity. The optimisation process gave an outcome that adequately showed how queueing can be managed in the packaging stage in an advanced manufacturing environment.
{"title":"PERFORMANCE OPTIMISATION ON WAITING TIME USING QUEUEING THEORY IN AN ADVANCED MANUFACTURING ENVIRONMENT","authors":"G. Salawu, G. Bright, C. Onunka","doi":"10.7166/31-4-2217","DOIUrl":"https://doi.org/10.7166/31-4-2217","url":null,"abstract":"Queueing is a common phenomenon in various stages of manufacturing systems and some other organisations. Queueing usually reduces the time required by managers and manufacturers to complete a desired task. The queueing mathematical theory is a viable tool for analysing a waiting line model. This research presents the implementation of robots at the packaging stage of a virtual manufacturing scenario in which mathematical models were used to describe each stage of the manufacturing process. Some suitable parameters and operating conditions were assumed, and the Newton-Raphson iteration formula was implemented for numerical analysis of the models. Simulation was carried out to achieve optimal values that could yield efficient productivity. The optimisation process gave an outcome that adequately showed how queueing can be managed in the packaging stage in an advanced manufacturing environment.","PeriodicalId":49493,"journal":{"name":"South African Journal of Industrial Engineering","volume":"31 1","pages":"9-18"},"PeriodicalIF":0.5,"publicationDate":"2020-12-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45089381","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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