Digital twins have emerged as a promising technology for maintenance applications,enabling organizations to simulate and monitor physical assets to improve their performance.In Operation and Maintenance(O&M),digit...Digital twins have emerged as a promising technology for maintenance applications,enabling organizations to simulate and monitor physical assets to improve their performance.In Operation and Maintenance(O&M),digital twin facilitates the diagnosis and prognosis of critical assets,forming the basis for smart maintenance planning and reducing downtime.However,there is a lack of standardized approaches for the qualifications of digital twins in maintenance,leading to low trustworthiness and limiting its application.This paper proposes a novel framework for the qualifications of digital twins in maintenance based on five pillars,namely fidelity,smartness,timeliness,integration,and standard compliance.We demonstrate the effectiveness of the framework through two case studies,showing how it can be implemented on digital twins for preventive maintenance and condition-based maintenance.Our proposed framework can help organizations across different industrial domains develop and implement digital twins in maintenance more effectively and efficiently,leading to significant benefits in terms of cost reduction,performance improvement,and sustainability.展开更多
In this 21st century a lot of women are experiencing marital challenges due to the various and important roles they perform in the home and in the society,which may require some psychological remedies.The research was...In this 21st century a lot of women are experiencing marital challenges due to the various and important roles they perform in the home and in the society,which may require some psychological remedies.The research was on marital stress and married working women:the role of coping strategies,self-concept and educational qualification.Three hundred and seventy-seven(377)participants whose ages were between 25 to 55 years(mean 40.63 and SD 7.59)participated in the study.Three research instruments were used for data collection while three-way Analysis of Variance was used for data analysis.Result disclosed that emotion-focused strategies yielded less manifestation of marital stress(1,369)=4.44,sig.=.036;in the same manner,those with higher educational qualification presented less manifestation of marital stress(1,369)=6.33,sig.=.012.It was equally specified that coping strategies together with self-concept had a joint impact on marital stress(1,369)=5.88,sig.=.016;a joint influence was also observed between self-concept and educational qualification on marital stress(1,369)=4.18,sig.=.042.Hence,married working women should strive for higher education and also use emotion-focused coping strategies in dealing with marital stress.展开更多
This article proposes a few tangent cones,which are relative to the constraint qualifications of optimization problems.With the upper and lower directional derivatives of an objective function,the characteristics of c...This article proposes a few tangent cones,which are relative to the constraint qualifications of optimization problems.With the upper and lower directional derivatives of an objective function,the characteristics of cones on the constraint qualifications are presented.The interrelations among the constraint qualifications,a few cones involved, and level sets of upper and lower directional derivatives are derived.展开更多
After analyzing the welding procedure knowledge in Chinese national standards for welding procedure qualification of steel pressure vessel from the point of establishing expert system, it can be divided into five type...After analyzing the welding procedure knowledge in Chinese national standards for welding procedure qualification of steel pressure vessel from the point of establishing expert system, it can be divided into five types of knowledge, i. e. practice, definition, regularity, process and description knowledge. The knowledge expression methods are established according to the different type of welding procedure knowledge. The reasoning process based on rule is adopted. And the reasoning engine is embedded among objects integrated with the knowledge base.展开更多
AAS was qualified as per pharmacopoeia requirements. Copper, manganese, mercury and cadmium hallow cathode lamps were used for qualification purposes. Design qualification and installation qualification met the criter...AAS was qualified as per pharmacopoeia requirements. Copper, manganese, mercury and cadmium hallow cathode lamps were used for qualification purposes. Design qualification and installation qualification met the criteria of user requirements. Wavelength accuracy and reproducibility, resolution and baseline stability are in compliance with user requirements. Characteristics concentration or sensitivity, detection limit and characteristics mass were performed as a part of operational qualification which is 0.062 μg/mL, 0.00354 μg/mL, 1.41 pg respectively. Results of % RSD for precision study is 0.352 and 0.487 for flame and graphite furnace mode respectively fulfilled criteria of qualification. Performance qualification results of 20 consecutive days demonstrate the predetermined specification. Analytical instrument qualification and method validation relationship is also described by assay performed on haemodialysis concentrate. Good precision (2) greater than 0.9997 for potassium, magnesium and calcium linear curves, lower detection limits for all three ingredients and robust assay data as a part of validation studies conform the qualified AAS for its intended application.展开更多
A qualification test for the reliability of a newly-developed Diver Gas Recovery System (DGRS) was carried out in the Naval Medical Research Institute of the People's Liberation Army, China from March 29 to April ...A qualification test for the reliability of a newly-developed Diver Gas Recovery System (DGRS) was carried out in the Naval Medical Research Institute of the People's Liberation Army, China from March 29 to April 2, 1995. A sequential test plan of high discrimination ratio for the mean time between failures (MTBF) was adopted. The test procedures simulated those of a 300 msw dive. A hyperbaric breathing machine was used for the simulation of diver's respiratory functions. Parameters, such as diving depth, respiratory minute volume (RMV), CO2 production, gas flow rate, partial pressure of carbon dioxide, and ambient temperature and himidity were all displayed and recorded with a microcomputer system. The results indicated that no failure occurred during the 91.5 h operation. According to the acceptance and rejection criteria specified in the statistical test plan, a no-failure score in the 88 h operation is acceptable. Therefore, the DGRS has been demonstrated to meet the requirements of MTBF specified in the contract.展开更多
Chinese Welding Training and Qualification Committee (CANB) was awarded the authorisation of IIW in 2000, and has issued nearly 2000 IIW diplomas by the end of 2004. Since Harbin Welding Training Institute(WTI Harbin)...Chinese Welding Training and Qualification Committee (CANB) was awarded the authorisation of IIW in 2000, and has issued nearly 2000 IIW diplomas by the end of 2004. Since Harbin Welding Training Institute(WTI Harbin) was founded based on Sino-German cooperation in 1984, it has trained all kinds of welding personnel 20000 and it made important contribution to the up-to-date system introduction of international welding training to China. The common questions in Germany foreign aid programs are: when German experts were on site, the project was on the operation; when he/they left, only memory was left. The outstanding achievements of Harbin Welding Training Institute tell us: when German experts were away, the cooperation program is not only run normally, but also gets persistent development, it is the successful model among the cooperation projects between China and Germany.展开更多
Based on the theoretical inference and experiment verification,a method was proposed to carry out the accelerated reliability qualification testing. First,theoretical inference was used to get the acceleration coeffic...Based on the theoretical inference and experiment verification,a method was proposed to carry out the accelerated reliability qualification testing. First,theoretical inference was used to get the acceleration coefficients of super Gauss vibration stress and temperature stress. Then, by applying these coefficients, an accelerated reliability qualification testing curve was obtained from the standard tests. Finally,the actual experiment on a digital marine control device was carried out under the proposed testing method.The experiment result shows that the proposed method can reduce the total experiment time and improve the efficiency of the reliability qualification test.展开更多
Some remarks are made on the use of the Abadie constraint qualification, the Guignard constraint qualifications and the Guignard regularity condition in obtaining weak and strong Kuhn-Tucker type optimality conditions...Some remarks are made on the use of the Abadie constraint qualification, the Guignard constraint qualifications and the Guignard regularity condition in obtaining weak and strong Kuhn-Tucker type optimality conditions in differentiable vector optimization problems.展开更多
With the increasing demand for new technologies in HPHT (high pressure high temperature) wells, more and more attention has been paid to the system of technical qualifications. Most established norms, standards and re...With the increasing demand for new technologies in HPHT (high pressure high temperature) wells, more and more attention has been paid to the system of technical qualifications. Most established norms, standards and recommended practices are written in prescribed formats, setting out methods, procedures and acceptance criteria for product design, manufacture and testing. However, established norms, standards or recommended practices may not adequately cover new technologies or applications. The technical qualification system is established in this paper, which can identify the potential failure modes and some activities in order to control the uncertainties and increase confidence of using new technology. A risk-based technical qualification system is used to assess non-traditional operations. It includes following seven main steps: system breakdown, technology assessment and classification, technical novelty, failure model and risk analysis, risk-based qualification planning and participation level development. The core of technical qualification system is to understand the ways and causes of system failure, and to carry out corresponding activities to provide evidence that the system will not fail. Through the technical identification process, the detailed equipment/operation specifications and identification requirements have been formulated. Different levels of participation are assigned for each eligibility activity, depending on the hazard and risk. It is proved that the application of the technical qualification principle in the systematic evaluation and control of the risks of new technologies or new applications is successful. In HPHT wells in particular, operators can move from a reactive approach to a proactive approach.展开更多
Recently, there is a growing interest in seismic qualification of ridges, buildings and mechanical equipment worldwide due to increase of accidents caused by earthquake. Severe earthquake can bring serious problems in...Recently, there is a growing interest in seismic qualification of ridges, buildings and mechanical equipment worldwide due to increase of accidents caused by earthquake. Severe earthquake can bring serious problems in the wind turbines and eventually lead to an interruption to their electric power supply. To overcome and prevent these undesirable problems, structural design optimization of a small vertical axis wind turbine has performed, in this study, for seismic qualification and lightweight by using a Genetic Algorithm (GA) subject to some design constraints such as the maximum stress limit, maximum deformation limit, and seismic acceleration gain limit. Also, the structural design optimizations were conducted for the four different initial design variable sets to confirm robustness of the optimization algorithm used. As a result, all the optimization results for the 4 different initial designs showed good agreement with each other properly. Thus the structural design optimization of a small vertical-axis wind turbine could be successfully accomplished.展开更多
With a view to standardizing the business operationsrelating to foreign investment of domestic and overseas secu-rities organizations and protecting the legitimate rights andinterests of investors,the China Security R...With a view to standardizing the business operationsrelating to foreign investment of domestic and overseas secu-rities organizations and protecting the legitimate rights andinterests of investors,the China Security Regulatory Commis-sion has promulgated the Provisional Regulations on theManagement of the Qualification of Domestic and OverseasSecurities Organizations to Engage in the Business Opera-tions concerning Shares Owned by Foreign Investors.TheseRegulations enter into force on December 1.1996.The wholetext is as follows:Chapter 1 General PrinciplesArticle 1 With a view to standardizing the businessoperations of domestic and overseas securities organizationswhich relate to shares owned by foreign investors and pro-展开更多
Investigation of optimality conditions has been one of the most interesting topics in the theory of multiobjective optimisation problems (MOP). To derive necessary optimality conditions of MOP, we consider assumptions...Investigation of optimality conditions has been one of the most interesting topics in the theory of multiobjective optimisation problems (MOP). To derive necessary optimality conditions of MOP, we consider assumptions called constraints qualifications. It is recognised that Guignard Constraint Qualification (GCQ) is the most efficient and general assumption for scalar objective optimisation problems;however, GCQ does not ensure Karush-Kuhn Tucker (KKT) necessary conditions for multiobjective optimisation problems. In this paper, we investigate the reasons behind that GCQ are not allowed to derive KKT conditions in multiobjective optimisation problems. Furthermore, we propose additional assumptions that allow one to use GCQ to derive necessary conditions for multiobjective optimisation problems. Finally, we also include sufficient conditions for multiobjective optimisation problems.展开更多
The BCQ and the Abadie CQ for infinite systems of convex inequalities in Banach spaces are characterized in terms of the upper semi-continuity of the convex cones generated by the subdifferentials of active convex fun...The BCQ and the Abadie CQ for infinite systems of convex inequalities in Banach spaces are characterized in terms of the upper semi-continuity of the convex cones generated by the subdifferentials of active convex functions. Some relationships with other constraint qualifications such as the CPLV and the Slate condition are also studied. Applications in best approximation theory are provided.展开更多
Consider an optimal procurement strategy for fresh produce,which is a type of perishable product.Due to the different quality provided by each manufacturer,the fresh produce qualification rates are dissimilar.Simultan...Consider an optimal procurement strategy for fresh produce,which is a type of perishable product.Due to the different quality provided by each manufacturer,the fresh produce qualification rates are dissimilar.Simultaneously,consumers demand is influenced by the freshness and price of products,as a result,the demand in the market is not fixed.In this scenario,how a particular retailer should develop an optimal procurement strategy will be a core issue in supply chain management.In order to address the above questions,the Bayesian approach is adopted to explore retailer optimal procurement strategies with uncertainty about product supply and market demand.Finally,simulation data are used to analyse the results of the proposed model and expected non-random model to illustrate the validity and feasibility of the proposed model.展开更多
The'European Level 5 Area'(EL5A)is a relatively new concept for Europe,giving an excellent opportunity to link the sectors for Vocational Education and Training(VET)and Higher Education(HE)to each other.Then i...The'European Level 5 Area'(EL5A)is a relatively new concept for Europe,giving an excellent opportunity to link the sectors for Vocational Education and Training(VET)and Higher Education(HE)to each other.Then it is about looking at qualifications at level 5 of the European Qualifications Framework(EQF)for Lifelong Learning and using them展开更多
This paper derives a new constraint qualification for nondifferential convex programming problem, by using the distance between the feasible set and the perturbed feasible sets. If the feasible sot is bounded, then th...This paper derives a new constraint qualification for nondifferential convex programming problem, by using the distance between the feasible set and the perturbed feasible sets. If the feasible sot is bounded, then this constraint qualification is weaker than Stater's constrains qualification.展开更多
OF the 517 large and small cities in the country, more than 300 have women mayors and vice mayors. These women play an important role in the construction and development of their cities. Ordinary Chinese people like t...OF the 517 large and small cities in the country, more than 300 have women mayors and vice mayors. These women play an important role in the construction and development of their cities. Ordinary Chinese people like to call their local officials "father-and- mother officials," but these展开更多
文摘Digital twins have emerged as a promising technology for maintenance applications,enabling organizations to simulate and monitor physical assets to improve their performance.In Operation and Maintenance(O&M),digital twin facilitates the diagnosis and prognosis of critical assets,forming the basis for smart maintenance planning and reducing downtime.However,there is a lack of standardized approaches for the qualifications of digital twins in maintenance,leading to low trustworthiness and limiting its application.This paper proposes a novel framework for the qualifications of digital twins in maintenance based on five pillars,namely fidelity,smartness,timeliness,integration,and standard compliance.We demonstrate the effectiveness of the framework through two case studies,showing how it can be implemented on digital twins for preventive maintenance and condition-based maintenance.Our proposed framework can help organizations across different industrial domains develop and implement digital twins in maintenance more effectively and efficiently,leading to significant benefits in terms of cost reduction,performance improvement,and sustainability.
文摘In this 21st century a lot of women are experiencing marital challenges due to the various and important roles they perform in the home and in the society,which may require some psychological remedies.The research was on marital stress and married working women:the role of coping strategies,self-concept and educational qualification.Three hundred and seventy-seven(377)participants whose ages were between 25 to 55 years(mean 40.63 and SD 7.59)participated in the study.Three research instruments were used for data collection while three-way Analysis of Variance was used for data analysis.Result disclosed that emotion-focused strategies yielded less manifestation of marital stress(1,369)=4.44,sig.=.036;in the same manner,those with higher educational qualification presented less manifestation of marital stress(1,369)=6.33,sig.=.012.It was equally specified that coping strategies together with self-concept had a joint impact on marital stress(1,369)=5.88,sig.=.016;a joint influence was also observed between self-concept and educational qualification on marital stress(1,369)=4.18,sig.=.042.Hence,married working women should strive for higher education and also use emotion-focused coping strategies in dealing with marital stress.
基金the Natural Science Foundation ofFujian Province of China(S0650021,2006J0215)the National Natural Science Foundation of China(10771086)
文摘This article proposes a few tangent cones,which are relative to the constraint qualifications of optimization problems.With the upper and lower directional derivatives of an objective function,the characteristics of cones on the constraint qualifications are presented.The interrelations among the constraint qualifications,a few cones involved, and level sets of upper and lower directional derivatives are derived.
文摘After analyzing the welding procedure knowledge in Chinese national standards for welding procedure qualification of steel pressure vessel from the point of establishing expert system, it can be divided into five types of knowledge, i. e. practice, definition, regularity, process and description knowledge. The knowledge expression methods are established according to the different type of welding procedure knowledge. The reasoning process based on rule is adopted. And the reasoning engine is embedded among objects integrated with the knowledge base.
文摘AAS was qualified as per pharmacopoeia requirements. Copper, manganese, mercury and cadmium hallow cathode lamps were used for qualification purposes. Design qualification and installation qualification met the criteria of user requirements. Wavelength accuracy and reproducibility, resolution and baseline stability are in compliance with user requirements. Characteristics concentration or sensitivity, detection limit and characteristics mass were performed as a part of operational qualification which is 0.062 μg/mL, 0.00354 μg/mL, 1.41 pg respectively. Results of % RSD for precision study is 0.352 and 0.487 for flame and graphite furnace mode respectively fulfilled criteria of qualification. Performance qualification results of 20 consecutive days demonstrate the predetermined specification. Analytical instrument qualification and method validation relationship is also described by assay performed on haemodialysis concentrate. Good precision (2) greater than 0.9997 for potassium, magnesium and calcium linear curves, lower detection limits for all three ingredients and robust assay data as a part of validation studies conform the qualified AAS for its intended application.
文摘A qualification test for the reliability of a newly-developed Diver Gas Recovery System (DGRS) was carried out in the Naval Medical Research Institute of the People's Liberation Army, China from March 29 to April 2, 1995. A sequential test plan of high discrimination ratio for the mean time between failures (MTBF) was adopted. The test procedures simulated those of a 300 msw dive. A hyperbaric breathing machine was used for the simulation of diver's respiratory functions. Parameters, such as diving depth, respiratory minute volume (RMV), CO2 production, gas flow rate, partial pressure of carbon dioxide, and ambient temperature and himidity were all displayed and recorded with a microcomputer system. The results indicated that no failure occurred during the 91.5 h operation. According to the acceptance and rejection criteria specified in the statistical test plan, a no-failure score in the 88 h operation is acceptable. Therefore, the DGRS has been demonstrated to meet the requirements of MTBF specified in the contract.
文摘Chinese Welding Training and Qualification Committee (CANB) was awarded the authorisation of IIW in 2000, and has issued nearly 2000 IIW diplomas by the end of 2004. Since Harbin Welding Training Institute(WTI Harbin) was founded based on Sino-German cooperation in 1984, it has trained all kinds of welding personnel 20000 and it made important contribution to the up-to-date system introduction of international welding training to China. The common questions in Germany foreign aid programs are: when German experts were on site, the project was on the operation; when he/they left, only memory was left. The outstanding achievements of Harbin Welding Training Institute tell us: when German experts were away, the cooperation program is not only run normally, but also gets persistent development, it is the successful model among the cooperation projects between China and Germany.
文摘Based on the theoretical inference and experiment verification,a method was proposed to carry out the accelerated reliability qualification testing. First,theoretical inference was used to get the acceleration coefficients of super Gauss vibration stress and temperature stress. Then, by applying these coefficients, an accelerated reliability qualification testing curve was obtained from the standard tests. Finally,the actual experiment on a digital marine control device was carried out under the proposed testing method.The experiment result shows that the proposed method can reduce the total experiment time and improve the efficiency of the reliability qualification test.
文摘Some remarks are made on the use of the Abadie constraint qualification, the Guignard constraint qualifications and the Guignard regularity condition in obtaining weak and strong Kuhn-Tucker type optimality conditions in differentiable vector optimization problems.
文摘With the increasing demand for new technologies in HPHT (high pressure high temperature) wells, more and more attention has been paid to the system of technical qualifications. Most established norms, standards and recommended practices are written in prescribed formats, setting out methods, procedures and acceptance criteria for product design, manufacture and testing. However, established norms, standards or recommended practices may not adequately cover new technologies or applications. The technical qualification system is established in this paper, which can identify the potential failure modes and some activities in order to control the uncertainties and increase confidence of using new technology. A risk-based technical qualification system is used to assess non-traditional operations. It includes following seven main steps: system breakdown, technology assessment and classification, technical novelty, failure model and risk analysis, risk-based qualification planning and participation level development. The core of technical qualification system is to understand the ways and causes of system failure, and to carry out corresponding activities to provide evidence that the system will not fail. Through the technical identification process, the detailed equipment/operation specifications and identification requirements have been formulated. Different levels of participation are assigned for each eligibility activity, depending on the hazard and risk. It is proved that the application of the technical qualification principle in the systematic evaluation and control of the risks of new technologies or new applications is successful. In HPHT wells in particular, operators can move from a reactive approach to a proactive approach.
文摘Recently, there is a growing interest in seismic qualification of ridges, buildings and mechanical equipment worldwide due to increase of accidents caused by earthquake. Severe earthquake can bring serious problems in the wind turbines and eventually lead to an interruption to their electric power supply. To overcome and prevent these undesirable problems, structural design optimization of a small vertical axis wind turbine has performed, in this study, for seismic qualification and lightweight by using a Genetic Algorithm (GA) subject to some design constraints such as the maximum stress limit, maximum deformation limit, and seismic acceleration gain limit. Also, the structural design optimizations were conducted for the four different initial design variable sets to confirm robustness of the optimization algorithm used. As a result, all the optimization results for the 4 different initial designs showed good agreement with each other properly. Thus the structural design optimization of a small vertical-axis wind turbine could be successfully accomplished.
文摘With a view to standardizing the business operationsrelating to foreign investment of domestic and overseas secu-rities organizations and protecting the legitimate rights andinterests of investors,the China Security Regulatory Commis-sion has promulgated the Provisional Regulations on theManagement of the Qualification of Domestic and OverseasSecurities Organizations to Engage in the Business Opera-tions concerning Shares Owned by Foreign Investors.TheseRegulations enter into force on December 1.1996.The wholetext is as follows:Chapter 1 General PrinciplesArticle 1 With a view to standardizing the businessoperations of domestic and overseas securities organizationswhich relate to shares owned by foreign investors and pro-
文摘Investigation of optimality conditions has been one of the most interesting topics in the theory of multiobjective optimisation problems (MOP). To derive necessary optimality conditions of MOP, we consider assumptions called constraints qualifications. It is recognised that Guignard Constraint Qualification (GCQ) is the most efficient and general assumption for scalar objective optimisation problems;however, GCQ does not ensure Karush-Kuhn Tucker (KKT) necessary conditions for multiobjective optimisation problems. In this paper, we investigate the reasons behind that GCQ are not allowed to derive KKT conditions in multiobjective optimisation problems. Furthermore, we propose additional assumptions that allow one to use GCQ to derive necessary conditions for multiobjective optimisation problems. Finally, we also include sufficient conditions for multiobjective optimisation problems.
基金the National Natural Science Foundation of China(Grant No 10271025)Program for New Century Excellent Talents in University
文摘The BCQ and the Abadie CQ for infinite systems of convex inequalities in Banach spaces are characterized in terms of the upper semi-continuity of the convex cones generated by the subdifferentials of active convex functions. Some relationships with other constraint qualifications such as the CPLV and the Slate condition are also studied. Applications in best approximation theory are provided.
基金This research was funded by the National Natural Science Foundation of China(NSFC)[Grant number 71671048,71901075]National Social Science Fund of China(NSSFC)Research of Public Choice Based on Arrow Axiom System and Arrow Impossibility Theorem[Grant number 17BJL025]+2 种基金Science Foundation of Ministry of Education of China(SFMEC):Research on The Influence Mechanism Of Social Trust Based on Multi-Modal Relationship of Sharing Economy[19YJCZH278]the Co-Construction Project of Philosophy and Social Science Planning Discipline in Guangdong Province[GD18XGL37]Innovative Talents Project of general universities in Guangdong Province[2018WQNCX146].
文摘Consider an optimal procurement strategy for fresh produce,which is a type of perishable product.Due to the different quality provided by each manufacturer,the fresh produce qualification rates are dissimilar.Simultaneously,consumers demand is influenced by the freshness and price of products,as a result,the demand in the market is not fixed.In this scenario,how a particular retailer should develop an optimal procurement strategy will be a core issue in supply chain management.In order to address the above questions,the Bayesian approach is adopted to explore retailer optimal procurement strategies with uncertainty about product supply and market demand.Finally,simulation data are used to analyse the results of the proposed model and expected non-random model to illustrate the validity and feasibility of the proposed model.
文摘The'European Level 5 Area'(EL5A)is a relatively new concept for Europe,giving an excellent opportunity to link the sectors for Vocational Education and Training(VET)and Higher Education(HE)to each other.Then it is about looking at qualifications at level 5 of the European Qualifications Framework(EQF)for Lifelong Learning and using them
基金the National Natural Science Foundation of China (No.19671053).
文摘This paper derives a new constraint qualification for nondifferential convex programming problem, by using the distance between the feasible set and the perturbed feasible sets. If the feasible sot is bounded, then this constraint qualification is weaker than Stater's constrains qualification.
文摘OF the 517 large and small cities in the country, more than 300 have women mayors and vice mayors. These women play an important role in the construction and development of their cities. Ordinary Chinese people like to call their local officials "father-and- mother officials," but these