Pub Date : 2000-01-24DOI: 10.1109/RAMS.2000.816304
B. Johnson, L. Gullo
This paper describes the continuing evolution of Honeywell's HIRAP, Honeywell In-Service Reliability Assessment Program. The approaches used in HIRAP remain consistent with industry efforts in the area of reliability assessment. The paper also presents a description of the process flows, showing simplifications that have occurred in the process over the last year. Unlike conventional reliability prediction methodologies, which focus solely on part failure rates, the methodologies presented here incorporate design failure rates, manufacturing process failure rates and other causes for equipment removal.
{"title":"Improvements in reliability assessment and prediction methodology","authors":"B. Johnson, L. Gullo","doi":"10.1109/RAMS.2000.816304","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816304","url":null,"abstract":"This paper describes the continuing evolution of Honeywell's HIRAP, Honeywell In-Service Reliability Assessment Program. The approaches used in HIRAP remain consistent with industry efforts in the area of reliability assessment. The paper also presents a description of the process flows, showing simplifications that have occurred in the process over the last year. Unlike conventional reliability prediction methodologies, which focus solely on part failure rates, the methodologies presented here incorporate design failure rates, manufacturing process failure rates and other causes for equipment removal.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114368048","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 : 2000-01-24DOI: 10.1109/RAMS.2000.816339
D. Rahe
The advent of HASS (highly accelerated stress screen) into the marketplace has enabled scores of manufacturers to dramatically reduce the number of production related failures from being shipped into their customer's hands. HASS is a screening process that uses accelerated techniques to uncover manufactured product weaknesses and flaws. The process requires the use of the HALT (highly accelerated life testing) results, and other product specific information to design the initial profile, and then to tune it for optimal effectiveness. This paper presents the HASS development process as it was applied to a client's uninterruptable power supply (UPS) product. This process is presented in a systematic approach to demonstrate the methods employed to create an effective screen.
{"title":"The HASS development process","authors":"D. Rahe","doi":"10.1109/RAMS.2000.816339","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816339","url":null,"abstract":"The advent of HASS (highly accelerated stress screen) into the marketplace has enabled scores of manufacturers to dramatically reduce the number of production related failures from being shipped into their customer's hands. HASS is a screening process that uses accelerated techniques to uncover manufactured product weaknesses and flaws. The process requires the use of the HALT (highly accelerated life testing) results, and other product specific information to design the initial profile, and then to tune it for optimal effectiveness. This paper presents the HASS development process as it was applied to a client's uninterruptable power supply (UPS) product. This process is presented in a systematic approach to demonstrate the methods employed to create an effective screen.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"13 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114346543","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 : 2000-01-24DOI: 10.1109/RAMS.2000.816307
Yin-Liong Mok, L. Ten
This paper reviews available plastic encapsulated microcircuit (PEM) reliability prediction models including the CNET, Thomson-CSF and RAC model. We examine the RAC (Reliability Analysis Center) model in detail, as it is the only usable model that considers the accelerating effects of temperature and humidity on PEM failures. Our intention is to provide constructive criticisms and propose amendments. We agreed with the assumptions made by the RAC model: types of packaging do not affect PEM failure rate; and a single activation energy of 0.8 eV may be adequate for different IC logic families. However, we feel that the RAC model should incorporate a term for EOS/ESD failures as they constitutes a high percentage (up to 43%) of IC failures. The RAC model should set an upper limit of 130/spl deg/C and 99% RH when using Peck's model to model temperature/humidity acceleration so as to avoid violating physics-of-failure considerations. It should consider treating microprocessor and memories as two different classes of devices due to the vast differences in their reliability as indicated by some literatures. We question if the reliability growth rate can be projected without restrictions. There should also be clearer indications of what constitutes "best commercial practices"-a prerequisite to apply the model.
{"title":"A review of plastic-encapsulated-microcircuit reliability-prediction models","authors":"Yin-Liong Mok, L. Ten","doi":"10.1109/RAMS.2000.816307","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816307","url":null,"abstract":"This paper reviews available plastic encapsulated microcircuit (PEM) reliability prediction models including the CNET, Thomson-CSF and RAC model. We examine the RAC (Reliability Analysis Center) model in detail, as it is the only usable model that considers the accelerating effects of temperature and humidity on PEM failures. Our intention is to provide constructive criticisms and propose amendments. We agreed with the assumptions made by the RAC model: types of packaging do not affect PEM failure rate; and a single activation energy of 0.8 eV may be adequate for different IC logic families. However, we feel that the RAC model should incorporate a term for EOS/ESD failures as they constitutes a high percentage (up to 43%) of IC failures. The RAC model should set an upper limit of 130/spl deg/C and 99% RH when using Peck's model to model temperature/humidity acceleration so as to avoid violating physics-of-failure considerations. It should consider treating microprocessor and memories as two different classes of devices due to the vast differences in their reliability as indicated by some literatures. We question if the reliability growth rate can be projected without restrictions. There should also be clearer indications of what constitutes \"best commercial practices\"-a prerequisite to apply the model.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"145 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"127508036","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 : 2000-01-24DOI: 10.1109/RAMS.2000.816286
J. Elerath
Most commercial enterprises want a meaningful yet simple method for determining product reliability. "Average", "annual" or "annualized" failure rates are selected because of their apparent simplicity. All involve some sort of "failure rate" averaging over some period of time. All are abbreviated AFR even though there are no accepted industry standard definitions for these terms or the processes and conditions for their measurement. If the failure rate is not constant in time, creating an average can easily generate meaningless results. A number of businesses use the term "failure rate" but are in fact calculating probabilities or time independent percentages. A basic premise for this paper is that the true underlying product failure rates are not constant in time. This paper presents a detailed discussion of different ways commercial industries calculate simple failure rate based metrics. It identifies some ambiguities in the definitions and resultant inaccuracies. It will help the reliability pundit understand the mathematical considerations, making him more aware of potential problems. This paper should help generalists and managers understand that the AFR's they calculate may be significantly different than those calculated by their suppliers and customers. This can result in substantially different numbers and conclusions. Averaging instantaneous failure rates should be done only to smooth data collected from a distribution known to have a constant failure rate.
{"title":"AFR: problems of definition, calculation and measurement in a commercial environment","authors":"J. Elerath","doi":"10.1109/RAMS.2000.816286","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816286","url":null,"abstract":"Most commercial enterprises want a meaningful yet simple method for determining product reliability. \"Average\", \"annual\" or \"annualized\" failure rates are selected because of their apparent simplicity. All involve some sort of \"failure rate\" averaging over some period of time. All are abbreviated AFR even though there are no accepted industry standard definitions for these terms or the processes and conditions for their measurement. If the failure rate is not constant in time, creating an average can easily generate meaningless results. A number of businesses use the term \"failure rate\" but are in fact calculating probabilities or time independent percentages. A basic premise for this paper is that the true underlying product failure rates are not constant in time. This paper presents a detailed discussion of different ways commercial industries calculate simple failure rate based metrics. It identifies some ambiguities in the definitions and resultant inaccuracies. It will help the reliability pundit understand the mathematical considerations, making him more aware of potential problems. This paper should help generalists and managers understand that the AFR's they calculate may be significantly different than those calculated by their suppliers and customers. This can result in substantially different numbers and conclusions. Averaging instantaneous failure rates should be done only to smooth data collected from a distribution known to have a constant failure rate.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"65 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124525914","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 : 2000-01-24DOI: 10.1109/RAMS.2000.816287
Ming-Wei Lu, R. Rudy
An automotive company's goal is to design and manufacture vehicles that will meet the needs and the expectations of the customers. It is essential for the design engineer to understand and take into account all sources of variation, which will be encountered by the system or component being developed. In this paper, the methods of derivation for the reliability test target requirement (at 95/sup th/ percentile customer usage severity level) from a given field target requirement (in C/100) is described. Formulas are derived under the assumption that both stress and strength are normally distributed, lognormally distributed, and Weibull distributed.
{"title":"Reliability test target development","authors":"Ming-Wei Lu, R. Rudy","doi":"10.1109/RAMS.2000.816287","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816287","url":null,"abstract":"An automotive company's goal is to design and manufacture vehicles that will meet the needs and the expectations of the customers. It is essential for the design engineer to understand and take into account all sources of variation, which will be encountered by the system or component being developed. In this paper, the methods of derivation for the reliability test target requirement (at 95/sup th/ percentile customer usage severity level) from a given field target requirement (in C/100) is described. Formulas are derived under the assumption that both stress and strength are normally distributed, lognormally distributed, and Weibull distributed.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"118 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126711426","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 : 2000-01-24DOI: 10.1109/RAMS.2000.816306
J. Elerath
Great strides have been made in creating a more realistic method for specifying disk drive reliability in a competitive commercial environment. Mean time between (before) failure (MTBF) is misleading and causes great conflict between drive manufacturers and drive integrators. The single most prominent cause is that the failure distribution for disk drives is not exponential during the first year of product use. To rectify this problem, drive hazard rate, in the form of a stair-step approximation to the Weibull, has been instituted as a standard way of representing reliability in the disk drive industry. Although not problem free, this method for specifying reliability is more easily correlated to field experience and can be used to more accurately calculate the expected number of returns and spares needed.
{"title":"Specifying reliability in the disk drive industry: No more MTBF's","authors":"J. Elerath","doi":"10.1109/RAMS.2000.816306","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816306","url":null,"abstract":"Great strides have been made in creating a more realistic method for specifying disk drive reliability in a competitive commercial environment. Mean time between (before) failure (MTBF) is misleading and causes great conflict between drive manufacturers and drive integrators. The single most prominent cause is that the failure distribution for disk drives is not exponential during the first year of product use. To rectify this problem, drive hazard rate, in the form of a stair-step approximation to the Weibull, has been instituted as a standard way of representing reliability in the disk drive industry. Although not problem free, this method for specifying reliability is more easily correlated to field experience and can be used to more accurately calculate the expected number of returns and spares needed.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"95 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131953420","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 : 2000-01-24DOI: 10.1109/RAMS.2000.816321
M. Kaminskiy, Vasiliy V. Krivtsov
A brief overview of the statistical aspects of warranty prediction is given as an introduction. The main discussion then focuses on warranty claim prediction for repairable products. Introduced by Kijima and Sumita (1986), a g-renewal process (GRP) can be considered as a model for major repair assumptions encountered in repairable product reliability analysis. These assumptions include "good-as-new", "same-as-old", the intermediate "better-than-old-but-worse-than-new", and "worse-than-old". A statistical procedure is developed for estimation of the GRP parameter, which is suggested to have engineering meaning of the effectiveness of the repair actions. A practical example of the GRP application in statistical warranty prediction is given as an illustration of the proposed estimation method. The paper arrives to the following conclusions: The GRP provides high flexibility in modeling real life failure occurrence processes by covering major repair assumptions encountered in practice. A Monte Carlo simulation can be considered as a method for statistical estimation of the GRP. Warranty claim prediction based on GRP provides a higher accuracy compared to the ORP or the NHPP.
{"title":"G-renewal process as a model for statistical warranty claim prediction","authors":"M. Kaminskiy, Vasiliy V. Krivtsov","doi":"10.1109/RAMS.2000.816321","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816321","url":null,"abstract":"A brief overview of the statistical aspects of warranty prediction is given as an introduction. The main discussion then focuses on warranty claim prediction for repairable products. Introduced by Kijima and Sumita (1986), a g-renewal process (GRP) can be considered as a model for major repair assumptions encountered in repairable product reliability analysis. These assumptions include \"good-as-new\", \"same-as-old\", the intermediate \"better-than-old-but-worse-than-new\", and \"worse-than-old\". A statistical procedure is developed for estimation of the GRP parameter, which is suggested to have engineering meaning of the effectiveness of the repair actions. A practical example of the GRP application in statistical warranty prediction is given as an illustration of the proposed estimation method. The paper arrives to the following conclusions: The GRP provides high flexibility in modeling real life failure occurrence processes by covering major repair assumptions encountered in practice. A Monte Carlo simulation can be considered as a method for statistical estimation of the GRP. Warranty claim prediction based on GRP provides a higher accuracy compared to the ORP or the NHPP.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"19 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133099034","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 : 2000-01-24DOI: 10.1109/RAMS.2000.816282
S. Vikman, A. Lonnqvist
A recent nationwide survey to the Swedish Engineering Industry disclosed that the understanding and use of reliability and safety methods by the small and medium sized companies on an average was distressingly low. Less than 30% of the smaller companies were familiar with reliability. In 1996, based on a survey and a following "out-line study", a new project was initiated by the Association of Swedish Engineering Industries, VI, and its Reliability Committee Te 5/2. The goal was to develop and document a program for "cooperative reliability development by small and medium-sized companies of the Swedish industrial sector". It will offer help to companies to initiate need based and local reliability work/activities. Starting point is an auditing/review of a company's existent process(es) and an audit of existing reliability status. Based on this, one will reach an understanding of in what way any "down-to-the-floor" simplified reliability-centered activity could be helpful. The final program will include necessary information and methods packages, training activities, expertise for managerial support and guidance during start-up and access to consultancy support where necessary for further implementation. This paper describes the project and its findings and illustrates the tools and methods developed for organizing individual down-to-the-floor reliability work programs by the industry.
{"title":"A reliability development program for the Swedish industry","authors":"S. Vikman, A. Lonnqvist","doi":"10.1109/RAMS.2000.816282","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816282","url":null,"abstract":"A recent nationwide survey to the Swedish Engineering Industry disclosed that the understanding and use of reliability and safety methods by the small and medium sized companies on an average was distressingly low. Less than 30% of the smaller companies were familiar with reliability. In 1996, based on a survey and a following \"out-line study\", a new project was initiated by the Association of Swedish Engineering Industries, VI, and its Reliability Committee Te 5/2. The goal was to develop and document a program for \"cooperative reliability development by small and medium-sized companies of the Swedish industrial sector\". It will offer help to companies to initiate need based and local reliability work/activities. Starting point is an auditing/review of a company's existent process(es) and an audit of existing reliability status. Based on this, one will reach an understanding of in what way any \"down-to-the-floor\" simplified reliability-centered activity could be helpful. The final program will include necessary information and methods packages, training activities, expertise for managerial support and guidance during start-up and access to consultancy support where necessary for further implementation. This paper describes the project and its findings and illustrates the tools and methods developed for organizing individual down-to-the-floor reliability work programs by the industry.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"30 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114299801","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 : 2000-01-24DOI: 10.1109/RAMS.2000.816288
M. Morelli
Benchmarking has been very instrumental to Otis Elevator Company's introduction and continual improvement of several key reliability engineering activities. The feasibility of using the highly accelerated life testing and highly accelerated stress screening methods for electronics' reliability testing were studied and implemented in part by benchmarking with other companies already practising the techniques and have been continually improved using another benchmarking arrangement. Failure modes and effects analysis methods were also studied by benchmarking with other companies and attending several "outside" training courses. Activities such as part burn-in and reliability prediction were eliminated after benchmarking and analyses were performed.
{"title":"Using benchmarking to introduce and improve reliability engineering","authors":"M. Morelli","doi":"10.1109/RAMS.2000.816288","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816288","url":null,"abstract":"Benchmarking has been very instrumental to Otis Elevator Company's introduction and continual improvement of several key reliability engineering activities. The feasibility of using the highly accelerated life testing and highly accelerated stress screening methods for electronics' reliability testing were studied and implemented in part by benchmarking with other companies already practising the techniques and have been continually improved using another benchmarking arrangement. Failure modes and effects analysis methods were also studied by benchmarking with other companies and attending several \"outside\" training courses. Activities such as part burn-in and reliability prediction were eliminated after benchmarking and analyses were performed.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"16 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"114632546","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 : 2000-01-24DOI: 10.1109/RAMS.2000.816300
V. Crk
The importance of degradation analysis as a method of assessing the reliability of highly reliable components and systems constantly increases due to the continuous efforts of the manufacturers to produce more and more reliable products. The presented methodology is an effective way to estimate the system's reliability by monitoring performance degradation. Its advantage is that the times to failure are not directly observed but the degradation that can be accurately measured. Consequently, the test time can be significantly shorter than if the times to failure are recorded.
{"title":"Reliability assessment from degradation data","authors":"V. Crk","doi":"10.1109/RAMS.2000.816300","DOIUrl":"https://doi.org/10.1109/RAMS.2000.816300","url":null,"abstract":"The importance of degradation analysis as a method of assessing the reliability of highly reliable components and systems constantly increases due to the continuous efforts of the manufacturers to produce more and more reliable products. The presented methodology is an effective way to estimate the system's reliability by monitoring performance degradation. Its advantage is that the times to failure are not directly observed but the degradation that can be accurately measured. Consequently, the test time can be significantly shorter than if the times to failure are recorded.","PeriodicalId":178321,"journal":{"name":"Annual Reliability and Maintainability Symposium. 2000 Proceedings. International Symposium on Product Quality and Integrity (Cat. No.00CH37055)","volume":"6 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2000-01-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133395423","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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