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A method for establishing a bearing residual life prediction model for process enhancement equipment based on rotor imbalance response analysis
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作者 Feng Wang Haoran Li +3 位作者 Zhenghui Zhang Yan Bai Hong Yin Jing Bian 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2024年第2期203-215,共13页
A rotating packed bed is a typical chemical process enhancement equipment that can strengthen micromixing and mass transfer.During the operation of the rotating packed bed,the nonreactants and products irregularly adh... A rotating packed bed is a typical chemical process enhancement equipment that can strengthen micromixing and mass transfer.During the operation of the rotating packed bed,the nonreactants and products irregularly adhere to the wire mesh packing in the rotor,thus resulting in an imbalance in the vibration of the rotor,which may cause serious damage to the bearing and material leakage.This study proposes a model prediction for estimating the bearing residual life of a rotating packed bed based on rotor imbalance response analysis.This method is used to determine the influence of the mass on the imbalance in the vibration of the rotor on bearing damage.The major influence on rotor vibration was found to be exerted by the imbalanced mass and its distribution radius,as revealed by the results of orthogonal experiments.Through implementing finite element analysis,the imbalance response curve for the rotating packed bed rotor was obtained,and a correlation among rotor imbalance mass,distribution radius of imbalance mass,and bearing residue life was established via data fitting.The predicted value of the bearing life can be used as the reference basis for an early safety warning of a rotating packed bed to effectively avoid accidents. 展开更多
关键词 Rotating packed bed Mass imbalance Harmonic response analysis Residual life Prediction model
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Economic Stress, Precariousness and Risk of High Blood Pressure: A Descriptive Survey of Life Models within Households of the Central Region of Cameroon
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作者 Jean Ndibi Abanda Ulrich Dama +5 位作者 Viviane Foussouo Ndoungue Anicet Onana Akoa Melkior Fobasso Dzeuta Alphonse Tedonge Asobochia Arsène Emilien Messi Ndzengue Désiré Tchoffo 《Health》 2024年第2期118-130,共13页
Context/Objective: High blood pressure (HBP) currently represents the most widespread chronic non-communicable disease in Cameroon. The increase in its prevalence in the country is the result of multiple factors inclu... Context/Objective: High blood pressure (HBP) currently represents the most widespread chronic non-communicable disease in Cameroon. The increase in its prevalence in the country is the result of multiple factors including economic stress imposed by precariousness, poor living conditions, sources of anxiety, anguish, depression and other behavioral disorders. Economic stress is a globalizing concept that integrates into a purely hermeneutic approach, a particular functioning of the nervous system of an individual who faces employment problems and precarious remuneration conditions. The non-satisfaction by an individual of his basic needs due to insufficient financial means can cause him to become irritable, aggressive, and socially and symbolically isolated, thereby increasing the desire to resort to morbid life models such as excessive consumption of narcotics and other psychoactive substances often associated with high blood pressure. The fight against the emergence of BPH is a complex, multifaceted and multifactorial reality that requires taking into account economic stress. The main objective of this survey is to describe the situation of economic stress within the Cameroonian population, which imposes precariousness and life models at risk of high blood pressure. Specifically, we determined the level of household income and the sources of income. Methods: A cross-sectional survey with a descriptive aim among five hundred households in the Central Region of Cameroon was conducted. A probabilistic technique called simple randomness was used. The number of households to be surveyed was determined indirectly using the Cochrane formula. Data collection in face-to-face mode using a physical questionnaire took place from July 1 to August 31, 2023, after obtaining ethical clearance from the Regional Health Research Ethics Committee, Human from the Center and an administrative authorization for data collection. Regarding their processing, the data was grouped during processing in Excel sheets. Normality and reliability tests of the collected data were carried out. For this, the Chi-square test was used for data with a qualitative value and that of Kolmogorov-Sminorf for data with a quantitative value. Descriptive analysis was possible using R software version 3.2, SPSS version 25.0, XLSTAT 2016, PAST and EXCEL programs from Microsoft Office 2013. Results: The main results highlight economic stress, with 45.60% of households surveyed earning less than US$154 per month;55% of household heads were women in single-parent families;14% of household heads were unemployed, 22% worked in the private sector and 19% were self-employed. This general economic situation leads to precarious living conditions, thereby increasing the risk of high blood pressure among the Cameroonian population. 展开更多
关键词 Economic Stress PRECARIOUSNESS High Blood Pressure life models Households
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A Building Information Modeling-Life Cycle Cost Analysis Integrated Model to Enhance Decisions Related to the Selection of Construction Methods at the Conceptual Design Stage of Buildings
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作者 Nkechi McNeil-Ayuk Ahmad Jrade 《Open Journal of Civil Engineering》 2024年第3期277-304,共28页
Life Cycle Cost Analysis (LCCA) provides a systematic approach to assess the total cost associated with owning, operating, and maintaining assets throughout their entire life. BIM empowers architects and designers to ... Life Cycle Cost Analysis (LCCA) provides a systematic approach to assess the total cost associated with owning, operating, and maintaining assets throughout their entire life. BIM empowers architects and designers to perform real-time evaluations to explore various design options. However, when integrated with LCCA, BIM provides a comprehensive economic perspective that helps stakeholders understand the long-term financial implications of design decisions. This study presents a methodology for developing a model that seamlessly integrates BIM and LCCA during the conceptual design stage of buildings. This integration allows for a comprehensive evaluation and analysis of the design process, ensuring that the development aligns with the principles of low carbon emissions by employing modular construction, 3D concrete printing methods, and different building design alternatives. The model considers the initial construction costs in addition to all the long-term operational, maintenance, and salvage values. It combines various tools and data through different modules, including energy analysis, Life Cycle Assessment (LCA), and Life Cycle Cost Analysis (LCCA) to execute a comprehensive assessment of the financial implications of a specific design option throughout the lifecycle of building projects. The development of the said model and its implementation involves the creation of a new plug-in for the BIM tool (i.e., Autodesk Revit) to enhance its functionalities and capabilities in forecasting the life-cycle costs of buildings in addition to generating associated cash flows, creating scenarios, and sensitivity analyses in an automatic manner. This model empowers designers to evaluate and justify their initial investments while designing and selecting potential construction methods for buildings, and enabling stakeholders to make informed decisions by assessing different design alternatives based on long-term financial considerations during the early stages of design. 展开更多
关键词 life Cycle Cost Analysis (LCCA) Building Information modeling (BIM) Cost Decision Modular Construction and 3D Concrete Printing
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Analysis of the Effect of Integrated Extended Care Model in Improving the Quality of Life of Elderly Patients with Type 2 Diabetes Mellitus
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作者 Lili Liu 《Journal of Clinical and Nursing Research》 2024年第4期174-179,共6页
Objective: To analyze the impact of an integrated extended care model on improving the quality of life of elderly patients with Type 2 Diabetes Mellitus (T2DM). Methods: A total of 176 patients admitted to the hospita... Objective: To analyze the impact of an integrated extended care model on improving the quality of life of elderly patients with Type 2 Diabetes Mellitus (T2DM). Methods: A total of 176 patients admitted to the hospital from March 2015 to February 2018 were selected and randomly assigned to an observation group and a control group, with 88 patients each. The control group implemented conventional nursing interventions, and the observation group carried out an integrated extended-care model. The level of glycemic control, quality of life, and daily medication adherence between both groups were compared. Results: The observation group showed significant improvement in the level of glycemic control, and their fasting blood glucose, 2-hour postprandial blood glucose, and glycated hemoglobin levels were significantly lower as compared with those in the study group (P < 0.05). The quality of life of the patients in the observation group was higher than that of the control group (P < 0.05). The observation group had a higher compliance score (95.48 ± 7.45) than the control group (81.31 ± 8.72) (t = 8.909, P < 0.05). Conclusion: The integrated extended care model allows patients to receive comprehensive and individualized nursing services after discharge, which improves the effect of drug therapy and the quality of life of patients. 展开更多
关键词 Integrated extended care model Elderly type 2 diabetes mellitus Quality of life
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Remaining useful life prediction based on nonlinear random coefficient regression model with fusing failure time data 被引量:1
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作者 WANG Fengfei TANG Shengjin +3 位作者 SUN Xiaoyan LI Liang YU Chuanqiang SI Xiaosheng 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2023年第1期247-258,共12页
Remaining useful life(RUL) prediction is one of the most crucial elements in prognostics and health management(PHM). Aiming at the imperfect prior information, this paper proposes an RUL prediction method based on a n... Remaining useful life(RUL) prediction is one of the most crucial elements in prognostics and health management(PHM). Aiming at the imperfect prior information, this paper proposes an RUL prediction method based on a nonlinear random coefficient regression(RCR) model with fusing failure time data.Firstly, some interesting natures of parameters estimation based on the nonlinear RCR model are given. Based on these natures,the failure time data can be fused as the prior information reasonably. Specifically, the fixed parameters are calculated by the field degradation data of the evaluated equipment and the prior information of random coefficient is estimated with fusing the failure time data of congeneric equipment. Then, the prior information of the random coefficient is updated online under the Bayesian framework, the probability density function(PDF) of the RUL with considering the limitation of the failure threshold is performed. Finally, two case studies are used for experimental verification. Compared with the traditional Bayesian method, the proposed method can effectively reduce the influence of imperfect prior information and improve the accuracy of RUL prediction. 展开更多
关键词 remaining useful life(RUL)prediction imperfect prior information failure time data NONLINEAR random coefficient regression(RCR)model
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Effect of health education based on information-motivationbehavioral skills model on patients with unilateral vestibular dysfunction 被引量:1
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作者 Qiong Shi Ruo-Jun Wu Jiang Liu 《World Journal of Clinical Cases》 SCIE 2024年第5期903-912,共10页
BACKGROUND Vestibular dysfunction(VH)is a common concomitant symptom of late peri-pheral vestibular lesions,which can be trauma,poisoning,infection,heredity,and neurodegeneration,but about 50%of the causes are unknown... BACKGROUND Vestibular dysfunction(VH)is a common concomitant symptom of late peri-pheral vestibular lesions,which can be trauma,poisoning,infection,heredity,and neurodegeneration,but about 50%of the causes are unknown.The study uses the information-motivation-behavioral skills(IMB)model for health education,effectively improve the quality of life,increase their self-confidence,reduce anxiety and depression,and effectively improve the psychological state of patients.AIM To explore the effect of health education based on the IMB model on the degree of vertigo,disability,anxiety and depression in patients with unilateral vestibular hypofunction.METHODS The clinical data of 80 patients with unilateral vestibular hypofunction from January 2019 to December 2021 were selected as the retrospective research objects,and they were divided into the control group and the observation group with 40 cases in each group according to different nursing methods.Among them,the control group was given routine nursing health education and guidance,and the observation group was given health education and guidance based on the IMB model.The changes in self-efficacy,anxiety and depression,and quality of life of patients with unilateral VH were compared between the two groups.RESULTS There was no significant difference in General Self-Efficacy Scale(GSES)scale scores between the two groups of patients before nursing(P>0.05),which was comparable;after nursing,the GSES scale scores of the two groups were higher than those before nursing.The nursing group was higher than the control group,and the difference was statistically significant(P<0.05).There was no significant difference in the scores of Hospital Anxiety and Depression Scale(HADS)and anxiety and depression subscales between the two groups before nursing(P>0.05).After nursing,the HADS score,anxiety,and depression subscale scores of the two groups of patients were lower than those before nursing,and the nursing group was lower than the control group,and the difference was statistically significant(P<0.05).After nursing,the Dizziness Handicap Inventory(DHI)scale and DHI-P,DHI-E and DHI-F scores in the two groups were decreased,and the scores in the nursing group were lower than those in the control group,and the difference was statistically significant(P<0.05).CONCLUSION Health education based on the IMB model can effectively improve patients'quality of life,increase self-efficacy of patients with unilateral vestibular hypofunction,enhance patients'confidence,enable patients to resume normal work and life as soon as possible,reduce patients'anxiety and depression,and effectively improve patients'psychological status. 展开更多
关键词 Information-motivation-behavioral skills model Health education Vestibular function Quality of life SELFEFFICACY
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Effects of health concept model-based detailed behavioral care on mood and quality of life in elderly patients with chronic heart failure
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作者 Ai-Di Zheng Li-Li Cai Jing Xu 《World Journal of Psychiatry》 SCIE 2023年第7期444-452,共9页
BACKGROUND With the intensification of social aging,the susceptibility of the elderly population to diseases has attracted increasing attention,especially chronic heart failure(CHF)that accounts for a large proportion... BACKGROUND With the intensification of social aging,the susceptibility of the elderly population to diseases has attracted increasing attention,especially chronic heart failure(CHF)that accounts for a large proportion of the elderly.AIM To evaluate the application value of health concept model-based detailed behavioral care in elderly patients with CHF.METHODS This study recruited 116 elderly CHF patients admitted from October 2018 to October 2020 and grouped them according to the nursing care that they received.The elderly patients who underwent health concept model-based detailed behavioral care were included in a study group(SG;n=62),and those who underwent routine detailed behavioral nursing intervention were included as a control group(CG;n=54).Patients’negative emotions(NEs),quality of life(QoL),and nutritional status were assessed using the self-rating anxiety/depression scale(SAS/SDS),the Minnesota Living with Heart Failure Questionnaire(MLHFQ),and the Modified Quantitative Subjective Global Assessment(MQSGA)of nutrition,respectively.Differences in rehabilitation efficiency,NEs,cardiac function(CF)indexes,nutritional status,QoL,and nursing satisfaction were comparatively analyzed.RESULTS A higher response rate was recorded in the SG vs the CG after intervention(P<0.05).After care,the left ventricular ejection fraction was higher while the left ventricular end-diastolic dimension and left ventricular end systolic diameter were lower in the SG compared with the CG(P<0.05).The post-intervention SAS and SDS scores,as well as MQSGA and MLHFQ scores,were also lower in the SG(P<0.05).The SG was also superior to the CG in the overall nursing satisfaction rate(P<0.05).CONCLUSION Health concept model-based detailed behavioral care has high application value in the nursing care of elderly CHF patients,and it can not only effectively enhance rehabilitation efficiency,but also mitigate patients’NEs and improve their CF and QoL. 展开更多
关键词 Chronic heart failure Elderly patients Health concept model Detailed behavioral care Patient mood Quality of life Nursing effect
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Key Issues for Modelling, Operation, Management and Diagnosis of Lithium Batteries: Current States and Prospects
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作者 Bo Yang Yucun Qian +2 位作者 Jianzhong Xu Yaxing Ren Yixuan Chen 《Energy Engineering》 EI 2024年第8期2085-2091,共7页
1 Introduction.With the continuous growth of the global population,the energy demand continues to increase.However,due to the dominance of fossil fuels in global energy and fossil fuels are non-renewable,it has led to... 1 Introduction.With the continuous growth of the global population,the energy demand continues to increase.However,due to the dominance of fossil fuels in global energy and fossil fuels are non-renewable,it has led to the global energy crisis[1].Besides,the use of fossil fuels will generate a mass of air pollutants(e.g.,carbon dioxide,sulfur dioxide,etc.),which will cause serious environmental pollution,climate change[2],etc.To resolve the aforementioned issues,countries around the world have implemented a variety of measures hoping to fundamentally adjust the global energy structure and achieve sustainable development.Thereinto,“Paris Agreement”reached in 2015 under the framework of“United Nations Framework Convention on Climate Change”aims to control the increase in the average temperature of the globe to within 2°C below preindustrial levels,and thereafter to peak global greenhouse gas emissions as soon as possible,continuously decreasing thereafter[3].United Kingdom plans to reduce the average exhaust emissions of“new cars”to approximately 50–70 g/km by 20230,which is roughly half of what it is now[4].In addition,China proposed a plan at“United Nations General Assembly”in 2020 to peak carbon dioxide emissions by 2030 and strive to achieve carbon neutrality by 2060.It is a fact that the whole world is committed to changing the current energy structure,protecting the Earth’s ecology,and achieving global sustainable development[5]. 展开更多
关键词 Lithium batteries optimization operation modelLING state estimation life prediction fault diagnosis
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The Construction of Integrated Nursing Model Prevention of Oxaliplatin Chemotherapy-Induced Peripheral Nerve Injury
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作者 Qiong Wen Xiaomei Cai 《Journal of Biosciences and Medicines》 2024年第2期340-348,共9页
Objective: To investigate the effect of the integrated nursing model in the prevention of chemotherapy-induced peripheral injury. Methods: A total of 60 tumor patients receiving oxaliplatin for 1 - 6 cycles of chemoth... Objective: To investigate the effect of the integrated nursing model in the prevention of chemotherapy-induced peripheral injury. Methods: A total of 60 tumor patients receiving oxaliplatin for 1 - 6 cycles of chemotherapy from January to September 2023 were selected. 30 patients were selected from January to March and divided into the control group, and 30 patients were selected from July to 9 as the experimental group. The control group received conventional chemotherapy nursing, while the experimental group received integrated nursing. Anxiety, peripheral nerve toxicity stage and quality of life score were compared between the two groups before and after intervention. Results: After intervention, the scores of the self-rating Anxiety Scale (SAS) and the total scores of the oxaliplatin Levi specific sensory neurotoxicity scale in the experimental group were significantly lower than those in the control group, and the differences were statistically significant (P< 0.05);The Quality of Life Scale (FACT-G) score of cancer patients was higher than that of control group, and the difference was statistically significant (P< 0.05). Conclusion: The integrated nursing model can effectively reduce the anxiety of patients, reduce the incidence of peripheral nerve injury and improve the quality of life of patients. 展开更多
关键词 Integrated Nursing Intervention model CHEMOTHERAPY Peripheral Nerve Toxicity ANXIETY Quality of life
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Analysis of the Application Effect of Family Collaborative Care Model on Elderly Patients with Type 2 Diabetes Mellitus and the Situation of Self-Care Ability
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作者 Yanling Zhao 《Journal of Clinical and Nursing Research》 2024年第4期393-398,共6页
Objective: To study the application effect of the family collaborative care model on elderly patients with type 2 diabetes mellitus and its influence on self-care ability. Methods: The elderly type 2 diabetes mellitus... Objective: To study the application effect of the family collaborative care model on elderly patients with type 2 diabetes mellitus and its influence on self-care ability. Methods: The elderly type 2 diabetes mellitus patients (400 cases) treated in our hospital between March 2020 and July 2023 were divided into two groups by randomized grouping method;the control group received the conventional nursing program, while the observation group received the family collaborative nursing model. Blood glucose level, self-care ability, and quality of life were compared between the groups. Results: The blood glucose level of the observation group was lower than that of the control group (P < 0.05). The self- care ability and quality of life scores of the observation group were higher than those of the control group (P < 0.05). Conclusion: The family collaborative care model for elderly patients with type 2 diabetes mellitus can promote their self- care ability, improve the effect of glycemic control, and improve their quality of life, and is suitable for further promotion and application. 展开更多
关键词 ELDERLY Type 2 diabetes mellitus Family collaborative care model Self-care ability Quality of life.
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Child Life照护模式在先天性心脏病患儿围手术期护理中的应用效果
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作者 高洋 蔡建平 本乐乐 《深圳中西医结合杂志》 2024年第13期122-125,共4页
目的:探讨Child Life照护模式在先天性心脏病患儿围手术期护理中的应用效果。方法:选取阜外华中心血管病医院2021年4至7月入院的80例先天性心脏病患儿,按照入院时间先后顺序进行分组,其中2021年4至5月入院的患儿分为对照组,2021年6至7... 目的:探讨Child Life照护模式在先天性心脏病患儿围手术期护理中的应用效果。方法:选取阜外华中心血管病医院2021年4至7月入院的80例先天性心脏病患儿,按照入院时间先后顺序进行分组,其中2021年4至5月入院的患儿分为对照组,2021年6至7月入院的患儿分为观察组,各40例。对照组患儿给予围手术期常规护理,观察组患儿在对照组基础上联合Child Life照护模式。比较两组患儿恐惧心理、护理治疗依从性。结果:护理后,两组患儿儿童医疗恐惧量表(CMFS)评分低于护理前,且观察组低于对照组,差异具有统计学意义(P<0.05)。观察组患儿各项护理治疗依从性量表评分高于对照组,差异具有统计学意义(P<0.05)。结论:Child Life照护模式应用于先天性心脏病患儿围手术期,能有效减轻患儿在医疗活动中的恐惧心理,增强其护理治疗依从性,保持患儿心理健康,提高医疗质量。 展开更多
关键词 先天性心脏病 围手术期护理 Child life照护模式
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Remaining Useful Life Model and Assessment of Mechanical Products: A Brief Review and a Note on the State Space Model Method 被引量:9
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作者 Yawei Hu Shujie Liu +1 位作者 Huitian Lu Hongchao Zhang 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2019年第1期11-30,共20页
The remaining useful life(RUL) prediction of mechanical products has been widely studied for online system performance reliability, device remanufacturing, and product safety(safety awareness and safety improvement). ... The remaining useful life(RUL) prediction of mechanical products has been widely studied for online system performance reliability, device remanufacturing, and product safety(safety awareness and safety improvement). These studies incorporated many di erent models, algorithms, and techniques for modeling and assessment. In this paper, methods of RUL assessment are summarized and expounded upon using two major methods: physics model based and data driven based methods. The advantages and disadvantages of each of these methods are deliberated and compared as well. Due to the intricacy of failure mechanism in system, and di culty in physics degradation observation, RUL assessment based on observations of performance variables turns into a science in evaluating the degradation. A modeling method from control systems, the state space model(SSM), as a first order hidden Markov, is presented. In the context of non-linear and non-Gaussian systems, the SSM methodology is capable of performing remaining life assessment by using Bayesian estimation(sequential Monte Carlo). Being e ective for non-linear and non-Gaussian dynamics, the methodology can perform the assessment recursively online for applications in CBM(condition based maintenance), PHM(prognostics and health management), remanufacturing, and system performance reliability. Finally, the discussion raises concerns regarding online sensing data for SSM modeling and assessment of RUL. 展开更多
关键词 REMAINING useful life State space model Online ASSESSMENT BAYESIAN estimation Particle filter REMANUFACTURING
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Reliability estimation and remaining useful lifetime prediction for bearing based on proportional hazard model 被引量:7
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作者 王鹭 张利 王学芝 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第12期4625-4633,共9页
As the central component of rotating machine,the performance reliability assessment and remaining useful lifetime prediction of bearing are of crucial importance in condition-based maintenance to reduce the maintenanc... As the central component of rotating machine,the performance reliability assessment and remaining useful lifetime prediction of bearing are of crucial importance in condition-based maintenance to reduce the maintenance cost and improve the reliability.A prognostic algorithm to assess the reliability and forecast the remaining useful lifetime(RUL) of bearings was proposed,consisting of three phases.Online vibration and temperature signals of bearings in normal state were measured during the manufacturing process and the most useful time-dependent features of vibration signals were extracted based on correlation analysis(feature selection step).Time series analysis based on neural network,as an identification model,was used to predict the features of bearing vibration signals at any horizons(feature prediction step).Furthermore,according to the features,degradation factor was defined.The proportional hazard model was generated to estimate the survival function and forecast the RUL of the bearing(RUL prediction step).The positive results show that the plausibility and effectiveness of the proposed approach can facilitate bearing reliability estimation and RUL prediction. 展开更多
关键词 PROGNOSTICS reliability estimation remaining useful life proportional hazard model
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Study on Strength and Life of Anisotropic Single Crystal Blade - Part I: Crystallographic Constitutive Models and Applications 被引量:7
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作者 尹泽勇 成晓鸣 +1 位作者 杨治国 岳珠峰 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2001年第1期18-23,共6页
The single crystal blade is one of the key technologies for improving the performance, durability and reliability of aero-engines and ground gas-turbine engines. However, the anisotropic mechanical properties of the s... The single crystal blade is one of the key technologies for improving the performance, durability and reliability of aero-engines and ground gas-turbine engines. However, the anisotropic mechanical properties of the single crystal material makes a great deal of difficulties on the development and the application of the single crystal blade, which is a challenge for the engineering application of the single crystal superalloy and the theoretic bases of the application. Some researches on the strength analysis and the life prediction of the anisotropic single crystal blade were carried out by the authors' research team. They are as follows. The crystallographic constitutive models for the plastic and the creep behaviors and the method of the rupture life prediction were established and verified. The tensile or the creep experiments for DD3 single crystal alloy with different orientations under different temperatures and different tensile rates or under different temperatures and different stress levels were carried out. The experimental data and the anisotropic properties at intermediate and high temperatures revealed by the experiments are significant for the application of the single crystal alloy. In addition, the experimental research for a kind of single crystal blade was also made. As the application of the researches the strength analysis and the life prediction were carried out for the single crystal blade of a certain aero-engine. In this part, the constitutive models and their applications are described, and the experimental research work will be described in part II. 展开更多
关键词 ANISOTROPY CREEP Gas turbines Mathematical models Plastic deformation Service life Single crystals Strength of materials SUPERALLOYS Temperature Tensile strength Tensile stress
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Grain size based low cycle fatigue life prediction model for nickel-based superalloy 被引量:12
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作者 Peng ZHANG Qiang ZHU +2 位作者 Gang CHEN He-yong QIN Chuan-jie WANG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第10期2102-2106,共5页
Nickel-based superalloys are easy to produce low cycle fatigue(LCF)damage when they are subjected to high temperature and mechanical stresses.Fatigue life prediction of nickel-based superalloys is of great importance ... Nickel-based superalloys are easy to produce low cycle fatigue(LCF)damage when they are subjected to high temperature and mechanical stresses.Fatigue life prediction of nickel-based superalloys is of great importance for their reliable practical application.To investigate the effects of total strain and grain size on LCF behavior,the high temperature LCF tests were carried out for a nickel-based superalloy.The results show that the fatigue lives decreased with the increase of strain amplitude and grain size.A new LCF life prediction model was established considering the effect of grain size on fatigue life.Error analyses indicate that the prediction accuracy of the new LCF life model is higher than those of Manson-Coffin relationship and Ostergren energy method. 展开更多
关键词 nickel-based superalloy low cycle fatigue life prediction model grain size
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Life Distribution Transformation Model of Planetary Gear System 被引量:2
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作者 Ming Li Li-Yang Xie +1 位作者 Hai-Yang Li Jun-Gang Ren 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2018年第2期208-215,共8页
Planetary gear systems have been widely used in transportation, construction, metallurgy, petroleum, aviation and other industrial fields. Under the same condition of power transmission, they have a more compact struc... Planetary gear systems have been widely used in transportation, construction, metallurgy, petroleum, aviation and other industrial fields. Under the same condition of power transmission, they have a more compact structure than ordinary gear train. However, some critical parts, such as sun gear, planet gear and ring gear often suffer from fatigue and wear under the conditions of high speed and heavy load. For reliability research, in order to predict the fatigue probability life of planetary gear system, detailed kinematic and mechanical analysis for a planetary gear system is firstly completed. Meanwhile, a gear bending fatigue test is carried out at a stress level to obtain the strength information of specific gears. Then, a life distribution transformation model is established according to the order statistics theory. Transformation process is that, the life distribution of test gear is transformed to that of single tooth, and then the life distribution of single tooth can be effectively transformed to that of the planetary gear system. In addition, the effectiveness of the transformation model is finally verified by a processing method with random censoring data. 展开更多
关键词 Planetary gear system Reliability modeling Probabilistic life Random censoring data
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Optimum design of equivalent accelerated life testing plans based on proportional hazards-proportional odds model 被引量:3
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作者 Tingting Huang Tongmin Jiang 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2011年第5期871-878,共8页
The optimum design of equivalent accelerated life testing plan based on proportional hazards-proportional odds model using D-optimality is presented. The defined equivalent test plan is the test plan that has the same... The optimum design of equivalent accelerated life testing plan based on proportional hazards-proportional odds model using D-optimality is presented. The defined equivalent test plan is the test plan that has the same value of the determinant of Fisher information matrix. The equivalent test plan of step stress accelerated life testing (SSALT) to a baseline optimum constant stress accelerated life testing (CSALT) plan is obtained by adjusting the censoring time of SSALT and solving the optimization problem for each case to achieve the same value of the determinant of Fisher information matrix as in the baseline optimum CSALT plan. Numer- ical examples are given finally which demonstrate the equivalent SSALT plan to the baseline optimum CSALT plan reduces almost half of the test time while achieving approximately the same estimation errors of model parameters. 展开更多
关键词 equivalent test plan proportional hazards-proportional odds (PH-PO) model D-OPTIMALITY constant stress step stress accelerated life testing (ALT).
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Using hybrid modeling for life cycle assessment of motor bike and electric bike 被引量:1
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作者 戴杜 冷如波 +1 位作者 张成 王成焘 《Journal of Central South University》 SCIE EI CAS 2005年第S2期77-80,共4页
Life-cycle assessment (LCA) is environmental evaluation of products, materials, and processes over their life cycle. Truncation uncertainty and corresponding uncertainty are main problems occurred in process life cycl... Life-cycle assessment (LCA) is environmental evaluation of products, materials, and processes over their life cycle. Truncation uncertainty and corresponding uncertainty are main problems occurred in process life cycle assessment (PLCA) modeling and economic input-output life cycle assessment (EIOLCA) modeling. Through combination of these two modelings in different life cycle stage and use of an uncertainty reduction strategy, a hybrid life cycle assessment modeling method was proposed in this study. Case studies were presented on gasoline-powered motorbikes (M-bike) and electricity-powered electric bike (E-bike). Web-based software was developed to analyze process environmental impacts. Results show that the largest part of life cycle energy (LCE) is consumed at use stage. Less energy is consumed in life cycle of E-bike than that of M-bike. GWP (Global Warming Potential), CO (Carbon Monoxide), PM10 (particulate matter) emission of M-bike are higher than that of E-bike, especially at use stage, AP (acidification Potential) emission of E-bike is higher than that of M-bike. Comprehensively, E-bike is energy efficient and less emitting, and better choice for urban private transportation. 展开更多
关键词 life CYCLE assessment hybrid modeling BIKE
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A new model for life prediction of GH4133 under TMF conditions 被引量:2
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作者 JianguoWang HongyingWang +2 位作者 ShipingXu LianqingWang YonglinKang 《Journal of University of Science and Technology Beijing》 CSCD 2002年第4期287-291,共5页
Thermal mechanical cyclic strain tests were carried out under in-phase andout-of-phase conditions on a Nickel-base Superalloy GH4133 in the temperature range of 571-823 degC. Based on analyzing the present models of T... Thermal mechanical cyclic strain tests were carried out under in-phase andout-of-phase conditions on a Nickel-base Superalloy GH4133 in the temperature range of 571-823 degC. Based on analyzing the present models of TMF (thermal mechanical fatigue) life prediction, a newmodel for predicting nickel-base superalloy TMF lifetime was proposed. TMF life of superalloy GH4133was calculated accurately based on the new model. Experimental TMF life has been compared with thecalculated results and all results fall in the scatter band of 1.5. The calculating results showthat the new model is not only simple, but also precise. This model will play great roles as lifeprediction of the metal materials and the engineering components subjected to non-isothermal serviceconditions. 展开更多
关键词 thermal mechanical fatigue life production Nickel-base superalloy fatigue lifetime prediction model IN-PHASE out-of-phase
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Path Classification and Estimation Model Based Prognosis of Pneumatic Cylinder Lifetime 被引量:1
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作者 CHEN Juan SONG Chunwen +1 位作者 QI Xiaoye WU Wei 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2012年第2期392-397,共6页
Prognosis is a key technology to improve reliability,safety and maintainability of products,a lot of researchers have been devoted to this technology.But to improve the predict accuracy of remaining life of products h... Prognosis is a key technology to improve reliability,safety and maintainability of products,a lot of researchers have been devoted to this technology.But to improve the predict accuracy of remaining life of products has been difficult.To predict the lifetime specification of pneumatic cylinders with high reliability and long lifetime and small specimen,this paper put forward the prognosis algorithm based on the path classification and estimation(PACE) model.PACE model is based entirely on failure data instead of failure threshold.Pneumatic cylinders normally characterize with failure mechanism wear and tear.Since the minimum working pressure increases with the number of working cycles,the minimum working pressure is chosen as degradation signal.PACE model is fundamentally composed of two operations:path classification and remaining useful life(RUL) estimation.Path classification is to classify a current degradation path as belonging to one or more of previously collected exemplary degradation paths.RUL estimation is to use the resulting memberships to estimate the remaining useful life.In order for verification and validation of PACE prognostic method,six pneumatic cylinders are tested.The test data is analyzed by PACE prognostics.It is found that the PACE based prognosis method has higher prediction accuracy and smaller variance and PACE model is significantly outperform population based prognostics especially for small specimen condition.PACE model based method solved the problem of prediction accuracy for small specimen pneumatic cylinders' prognosis. 展开更多
关键词 lifetime prognosis remaining useful life(RUL) path classification and estimation model Weibull distribution pneumatic cylinder
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