Pub Date : 2008-01-28DOI: 10.1109/RAMS.2008.4925828
Bo Yang, Huajun Hu, Jun Zhou
For a software development project, when to stop testing the software and release it for operation is of great importance as it impacts both the software reliability and the total cost of the project. Software release time determination, therefore, has attracted a lot of research in the past two decades and several new cost models have been developed in the literature recently. In most research on this topic, the approach taken is to minimize the expected total cost (ETC) of the software project, or further consider the software reliability requirement. However, because the actual total cost (ATC) of the software project is a random variable, minimization of the ETC does not guarantee that the ATC will be near this minimum. In fact, there exists certain risk that the ATC may exceed the ETC to an intolerable extent, which, despite its importance, has not been addressed in most related research. In this paper, we study the above mentioned risk problem for software release time determination and propose a new approach which could be helpful for management to control the risk of the project being over-budget. A numerical example is given to illustrate the solution procedures of the proposed approach.
{"title":"Optimal software release time determination with risk constraint","authors":"Bo Yang, Huajun Hu, Jun Zhou","doi":"10.1109/RAMS.2008.4925828","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925828","url":null,"abstract":"For a software development project, when to stop testing the software and release it for operation is of great importance as it impacts both the software reliability and the total cost of the project. Software release time determination, therefore, has attracted a lot of research in the past two decades and several new cost models have been developed in the literature recently. In most research on this topic, the approach taken is to minimize the expected total cost (ETC) of the software project, or further consider the software reliability requirement. However, because the actual total cost (ATC) of the software project is a random variable, minimization of the ETC does not guarantee that the ATC will be near this minimum. In fact, there exists certain risk that the ATC may exceed the ETC to an intolerable extent, which, despite its importance, has not been addressed in most related research. In this paper, we study the above mentioned risk problem for software release time determination and propose a new approach which could be helpful for management to control the risk of the project being over-budget. A numerical example is given to illustrate the solution procedures of the proposed approach.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"64 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"123486688","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 : 2008-01-28DOI: 10.1109/RAMS.2008.4925799
E. Droguett, A. Mosleh
This paper presents a methodology for the reliability assessment of systems under development. The methodology employs Bayesian data analysis techniques to estimate reliability measures based on various types of data such as warranty data, test data, and engineering judgments regarding the impact of design changes on the system reliability. It also provides the possibility of incorporating evidence concerning previous revisions of the same system or even information on systems that are only similar to the one under development. The methodology is validated against observed failure data from a diagnostic medical system. An example of application in the context of the automotive industry is presented as well.
{"title":"Use of heritage data and other partially applicable information in reliability prediction of systems under development","authors":"E. Droguett, A. Mosleh","doi":"10.1109/RAMS.2008.4925799","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925799","url":null,"abstract":"This paper presents a methodology for the reliability assessment of systems under development. The methodology employs Bayesian data analysis techniques to estimate reliability measures based on various types of data such as warranty data, test data, and engineering judgments regarding the impact of design changes on the system reliability. It also provides the possibility of incorporating evidence concerning previous revisions of the same system or even information on systems that are only similar to the one under development. The methodology is validated against observed failure data from a diagnostic medical system. An example of application in the context of the automotive industry is presented as well.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"7 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"130974225","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 : 2008-01-28DOI: 10.1109/RAMS.2008.4925764
B. Castanier, T. Yeung
We develop an inspection and maintenance policy to minimize the cost of maintaining a given section of road or highway when there is a great deal of uncertainty in the degradation process. We propose to model the degradation of a section of road based on the proliferation and growth of cracks. We utilize a combination of a Poisson and gamma process to account for the tremendous amount of uncertainty and difficulty in predicting the proliferation of cracks. Our policy defines the optimal inspection interval as well as the minimum threshold at which to perform crack repairs. Furthermore, our policy contains a safety constraint to prevent the probability of a ldquocatastrophicrdquo failure from exceeding a pre-determined reliability value. Numerical calculations have shown that our model will extend the lifecycle of the road by performing preventive, conditioned-based maintenance to slow down the growth of cracks. Classical preventive maintenance policies usually shorten the lifecycle by forcing earlier renewals.
{"title":"Optimal highway maintenance policies under uncertainty","authors":"B. Castanier, T. Yeung","doi":"10.1109/RAMS.2008.4925764","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925764","url":null,"abstract":"We develop an inspection and maintenance policy to minimize the cost of maintaining a given section of road or highway when there is a great deal of uncertainty in the degradation process. We propose to model the degradation of a section of road based on the proliferation and growth of cracks. We utilize a combination of a Poisson and gamma process to account for the tremendous amount of uncertainty and difficulty in predicting the proliferation of cracks. Our policy defines the optimal inspection interval as well as the minimum threshold at which to perform crack repairs. Furthermore, our policy contains a safety constraint to prevent the probability of a ldquocatastrophicrdquo failure from exceeding a pre-determined reliability value. Numerical calculations have shown that our model will extend the lifecycle of the road by performing preventive, conditioned-based maintenance to slow down the growth of cracks. Classical preventive maintenance policies usually shorten the lifecycle by forcing earlier renewals.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"182 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114529867","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 : 2008-01-28DOI: 10.1109/rams.2008.4925772
K. Gee, D. Mathias
In the event of a space launch vehicle explosion during ascent, the debris field generated by the explosion poses a risk to the crew. To evaluate this risk, a model of the debris environment was created and used to determine the probability of a debris strike on the crew module. The model uses experimental data to determine the initial debris field due to a launch vehicle explosion and computes the trajectory of each piece of debris. The trajectory of the crew module after the abort is also computed. The relative position of the debris field and the crew module is determined as a function of time after abort and explosion. A debris flux about the crew module is computed based on this information. The debris flux is used to compute the probability of a debris strike on the crew module using the Poisson distribution. The effect of system and model parameters - such as warning time, the number of debris pieces and abort system thrust- on the debris strike probability is assessed.
{"title":"Assessment of launch vehicle debris risk during ascent aborts","authors":"K. Gee, D. Mathias","doi":"10.1109/rams.2008.4925772","DOIUrl":"https://doi.org/10.1109/rams.2008.4925772","url":null,"abstract":"In the event of a space launch vehicle explosion during ascent, the debris field generated by the explosion poses a risk to the crew. To evaluate this risk, a model of the debris environment was created and used to determine the probability of a debris strike on the crew module. The model uses experimental data to determine the initial debris field due to a launch vehicle explosion and computes the trajectory of each piece of debris. The trajectory of the crew module after the abort is also computed. The relative position of the debris field and the crew module is determined as a function of time after abort and explosion. A debris flux about the crew module is computed based on this information. The debris flux is used to compute the probability of a debris strike on the crew module using the Poisson distribution. The effect of system and model parameters - such as warning time, the number of debris pieces and abort system thrust- on the debris strike probability is assessed.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"129379421","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 : 2008-01-28DOI: 10.1109/RAMS.2008.4925773
D. Mathias, S. Go, K. Gee, S. Lawrence
A simulation-based risk assessment approach is presented and is applied to the analysis of abort during the ascent phase of a space exploration mission. The approach utilizes groupings of launch vehicle failures, referred to as failure bins, which are mapped to corresponding failure environments. Physical models are used to characterize the failure environments in terms of the risk due to blast overpressure, resulting debris field, and the thermal radiation due to a fireball. The resulting risk to the crew is dynamically modeled by combining the likelihood of each failure, the severity of the failure environments as a function of initiator and time of the failure, the robustness of the crew module, and the warning time available due to early detection. The approach is shown to support the launch vehicle design process by characterizing the risk drivers and identifying regions where failure detection would significantly reduce the risk to the crew.
{"title":"Simulation assisted risk assessment applied to launch vehicle conceptual design","authors":"D. Mathias, S. Go, K. Gee, S. Lawrence","doi":"10.1109/RAMS.2008.4925773","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925773","url":null,"abstract":"A simulation-based risk assessment approach is presented and is applied to the analysis of abort during the ascent phase of a space exploration mission. The approach utilizes groupings of launch vehicle failures, referred to as failure bins, which are mapped to corresponding failure environments. Physical models are used to characterize the failure environments in terms of the risk due to blast overpressure, resulting debris field, and the thermal radiation due to a fireball. The resulting risk to the crew is dynamically modeled by combining the likelihood of each failure, the severity of the failure environments as a function of initiator and time of the failure, the robustness of the crew module, and the warning time available due to early detection. The approach is shown to support the launch vehicle design process by characterizing the risk drivers and identifying regions where failure detection would significantly reduce the risk to the crew.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"55 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"115404302","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 : 2008-01-28DOI: 10.1109/RAMS.2008.4925813
N. Bidokhti
This paper will discuss the importance of defining reliability and availability requirements upfront and its role in product development life cycle. In addition, it will review how to trace the requirements throughout the product life cycle. In designing a new product, much time and effort is spent defining time to market and functional requirements. In the mean time there is usually less attention paid to reliability, availability and fault management requirements. Therefore, defining clear product reliability & availability requirements becomes an afterthought, or it is only modeled once the product architecture is completed. At the first glance it makes sense, since the design team may not be familiar with reliability, availability and fault management requirements. The team tends to address the functional requirements before any other types of requirements. This is the natural course of action; however this type of thought process will lend itself to building a less desirable product. Knowing these facts, how do we address this necessary and important aspect of a product design as early in the development life cycle process as possible?
{"title":"The impact of reliability requirements on development life cycle","authors":"N. Bidokhti","doi":"10.1109/RAMS.2008.4925813","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925813","url":null,"abstract":"This paper will discuss the importance of defining reliability and availability requirements upfront and its role in product development life cycle. In addition, it will review how to trace the requirements throughout the product life cycle. In designing a new product, much time and effort is spent defining time to market and functional requirements. In the mean time there is usually less attention paid to reliability, availability and fault management requirements. Therefore, defining clear product reliability & availability requirements becomes an afterthought, or it is only modeled once the product architecture is completed. At the first glance it makes sense, since the design team may not be familiar with reliability, availability and fault management requirements. The team tends to address the functional requirements before any other types of requirements. This is the natural course of action; however this type of thought process will lend itself to building a less desirable product. Knowing these facts, how do we address this necessary and important aspect of a product design as early in the development life cycle process as possible?","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"54 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116228120","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 : 2008-01-28DOI: 10.1109/RAMS.2008.4925791
G. Poncelin, Jean-Pierre P. Derain, A. Cauvin, D. Dufrene
Nowadays, industrial competition is based on the Total Cost Ownership of the products (TCO). This is particularly true for big complex systems such as helicopters, for which the maintenance costs, often take the largest part of this TCO. Thus the challenge for such integrators is to invest in reliability engineering projects aimed at increasing their product's reliability to market them with the lowest TCO. To do so, industrialists need tools allowing them to predict the gain on products TCO realized with the development of reliability increasing projects during the design phase. Because of the complexity of the reliability parameter, the existing reliability engineering tools are not directly applicable and require to be adapted for a complete and direct exploitation in industry.
{"title":"Development of a design-for-reliability method for complex systems","authors":"G. Poncelin, Jean-Pierre P. Derain, A. Cauvin, D. Dufrene","doi":"10.1109/RAMS.2008.4925791","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925791","url":null,"abstract":"Nowadays, industrial competition is based on the Total Cost Ownership of the products (TCO). This is particularly true for big complex systems such as helicopters, for which the maintenance costs, often take the largest part of this TCO. Thus the challenge for such integrators is to invest in reliability engineering projects aimed at increasing their product's reliability to market them with the lowest TCO. To do so, industrialists need tools allowing them to predict the gain on products TCO realized with the development of reliability increasing projects during the design phase. Because of the complexity of the reliability parameter, the existing reliability engineering tools are not directly applicable and require to be adapted for a complete and direct exploitation in industry.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"73 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127240578","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 : 2008-01-28DOI: 10.1109/RAMS.2008.4925806
B. Honari, J. Donovan, T. Joyce, S. Wilson
Accelerated environmental stress tests (EST) are applied during the manufacturing process to improve reliability by precipitating and detecting latent defects. This test represents an in-process manufacturing screen and the objective of performing it is to avoid early field failures that reduce the customer satisfaction level and increase warranty and compensation costs. Temperature cycling during EST is one of the most commonly used test procedures. Although it is an expensive and energy intensive procedure, usually a lengthy test is initially recommended for a new product. Based on the product test performance or a possible manufacturing process modification, the test duration and regime may be changed after some period. Even if the number of test cycles is reduced, EST continues to be an expensive test and a major process bottleneck. This paper uses generalized linear modeling (GLM) to investigate the effects of the production and EST test variables on the population under test. Both the number of units rejected and the time to failure can be modeled as a regression function of covariates representative of the test environment. The field reliability function is written as a product of the unconditional reliability in each segment of the test profile such as dwell, ramp, etc. The next step is to apply the result of the temperature cycle EST GLM to a mathematical cost model. This cost model includes both the test cost and the warranty and compensation costs of the early field failures. The optimum test regime and number of cycles, which minimizes the total cost is determined by combining the GLM and the cost model. In this way the production test regime can be optimized in terms of field reliability/test cost trade-off.
{"title":"Application of generalized linear models for optimizing production stress testing","authors":"B. Honari, J. Donovan, T. Joyce, S. Wilson","doi":"10.1109/RAMS.2008.4925806","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925806","url":null,"abstract":"Accelerated environmental stress tests (EST) are applied during the manufacturing process to improve reliability by precipitating and detecting latent defects. This test represents an in-process manufacturing screen and the objective of performing it is to avoid early field failures that reduce the customer satisfaction level and increase warranty and compensation costs. Temperature cycling during EST is one of the most commonly used test procedures. Although it is an expensive and energy intensive procedure, usually a lengthy test is initially recommended for a new product. Based on the product test performance or a possible manufacturing process modification, the test duration and regime may be changed after some period. Even if the number of test cycles is reduced, EST continues to be an expensive test and a major process bottleneck. This paper uses generalized linear modeling (GLM) to investigate the effects of the production and EST test variables on the population under test. Both the number of units rejected and the time to failure can be modeled as a regression function of covariates representative of the test environment. The field reliability function is written as a product of the unconditional reliability in each segment of the test profile such as dwell, ramp, etc. The next step is to apply the result of the temperature cycle EST GLM to a mathematical cost model. This cost model includes both the test cost and the warranty and compensation costs of the early field failures. The optimum test regime and number of cycles, which minimizes the total cost is determined by combining the GLM and the cost model. In this way the production test regime can be optimized in terms of field reliability/test cost trade-off.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"22 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125437950","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 : 2008-01-28DOI: 10.1109/RAMS.2008.4925789
V. Loll
Design for reliability requires a different approach from failure reporting and corrective action system (FRACAS) and test, analyze and fix (TAAF) both of which are tools for reliability improvement of already designed hardware. The physics of failure analysis approach should be used focusing on each failure mode separately. Through a step by step design analysis and test process, the number of potential failure modes should be reduced. As many failure modes as possible should be mitigated by appropriate design changes and the remaining failure modes should be controlled through adequate design stress vs. strength margins. The failure modes with insufficient margins (meaning high likelihood of occurrence in the time of interest) should be extensively analyzed and tested to ensure that they do not contribute to an unacceptable number of failures in the field. The use of this method requires that the equipment manufacturer also actively collect and list failure modes for previous products as well as for components, materials and processes.
{"title":"Optimizing the number of failure modes for design analysis based on physics of failure","authors":"V. Loll","doi":"10.1109/RAMS.2008.4925789","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925789","url":null,"abstract":"Design for reliability requires a different approach from failure reporting and corrective action system (FRACAS) and test, analyze and fix (TAAF) both of which are tools for reliability improvement of already designed hardware. The physics of failure analysis approach should be used focusing on each failure mode separately. Through a step by step design analysis and test process, the number of potential failure modes should be reduced. As many failure modes as possible should be mitigated by appropriate design changes and the remaining failure modes should be controlled through adequate design stress vs. strength margins. The failure modes with insufficient margins (meaning high likelihood of occurrence in the time of interest) should be extensively analyzed and tested to ensure that they do not contribute to an unacceptable number of failures in the field. The use of this method requires that the equipment manufacturer also actively collect and list failure modes for previous products as well as for components, materials and processes.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126186800","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 : 2008-01-28DOI: 10.1109/RAMS.2008.4925801
M. Monnin, B. Iung, O. Sénéchal, P. Lelan
Availability is a determining factor in systems characterization. Because military systems must act in a hostile environment, they are particularly vulnerable in situations of unavailability. Military weapon systems can become unavailable due to system failures or damage to the system; in both cases, system regeneration is needed to restore availability. However, very few of the general dependability studies or even the more specific availability studies take battlefield damage into account. This paper aims to define principles for weapon systems modeling that integrate both system failure and system damage, as well as the possibility of regeneration, into operational availability assessment. This modeling method uses a unified failure/damage approach based on state-space modeling.
{"title":"Dynamic model for assessing impact of regeneration actions on system availability: Application to weapon systems","authors":"M. Monnin, B. Iung, O. Sénéchal, P. Lelan","doi":"10.1109/RAMS.2008.4925801","DOIUrl":"https://doi.org/10.1109/RAMS.2008.4925801","url":null,"abstract":"Availability is a determining factor in systems characterization. Because military systems must act in a hostile environment, they are particularly vulnerable in situations of unavailability. Military weapon systems can become unavailable due to system failures or damage to the system; in both cases, system regeneration is needed to restore availability. However, very few of the general dependability studies or even the more specific availability studies take battlefield damage into account. This paper aims to define principles for weapon systems modeling that integrate both system failure and system damage, as well as the possibility of regeneration, into operational availability assessment. This modeling method uses a unified failure/damage approach based on state-space modeling.","PeriodicalId":143940,"journal":{"name":"2008 Annual Reliability and Maintainability Symposium","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2008-01-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125985689","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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