Bayesian sequential testing for exponential life system with reliability growth

A Bayesian sequential testing method is proposed to evaluate system reliability index with reliability growth during development.The method develops a reliability growth model of repairable systems for failure censored test,and figures out the approach to determine the prior distribution of the system failure rate by applying the reliability growth model to incorporate the multistage test data collected from system development.Furthermore,the procedure for the Bayesian sequential testing is derived for the failure rate of the exponential life system,which enables the decision to terminate or continue development test.Finally,a numerical example is given to illustrate the efficiency of the proposed model and procedure.

Life Distribution Transformation Model of Planetary Gear System

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.

Nine requirements for the origin of Earth’s life:Not at the hydrothermal vent, but in a nuclear geyser system

The origin of life on Earth remains enigmatic with diverse models and debates.Here we discuss essential requirements for the first emergence of life on our planet and propose the following nine requirements:(1)an energy source(ionizing radiation and thermal energy);(2)a supply of nutrients(P.K.REE.etc.);(3)a supply of life-constituting major elements;(4)a high concentration of reduced gases such as CH4,HCN and NH3;(5)dry-wet cycles to create membranes and polymerize RNA;(6)a non-toxic aqueous environment;(7)Na-poor water;(8)highly diversified environments,and(9)cyclic conditions,such as dayto-night,hot-to-cold etc.Based on these nine requirements,we evaluate previously proposed locations for the origin of Earth’s life,including:(1)Darwin’s"warm little pond",leading to a"prebiotic soup"for life;(2)panspermia or Neo-panspermia(succession model of panspermia);(3)transportation from/through Mars;(4)a deepsea hydrothermal system;(5)an on-land subduct ion-zone hot spring,and(6)a geyser systems driven by a natural nuclear reactor.We conclude that location(6)is the most ideal candidate for the o rigin point for Earth’s life because of its efficiency in continuously supplying both the energy and the necessary materials for life,thereby maintaining the essential"cradle"for its initial development.We also emphasize that falsifiable working hypothesis provides an important tool to evaluate one of the biggest mysteries of the universe-the origin of life.

Remaining useful life prediction for a nonlinear multi-degradation system with public noise

To predict the remaining useful life(RUL) for a class of nonlinear multi-degradation systems, a method is presented. In the real industrial processes, systems are usually composed by several parts or components, and these parts or components are working in the same environment, thus the degradations of these parts or components will be influenced by common factors. To describe such a phenomenon in degradations, a multi-degradation model with public noise is proposed. To identify the degradation states and the unknown parameters, an iterative estimation method is proposed by using the Kalman filter and the expectation maximization(EM) algorithm. Next, with known thresholds,the RUL of each degradation can be predicted by using the first hitting time(FHT). In addition, the RUL of the whole system can be obtained by a Copula function. Finally, a practical case is used to demonstrate the method proposed.

The Study of Contact Pressure Analyses and Prediction of Dynamic Fatigue Life for Linear Guideways System

The application of the linear guideways is very extensive, such as automation equipment, heavy-duty carry equipment, heavy-cut machining tool, CNC grinding machine, large-scale planning machine and machining center with the demand of high rigidity and heavy load. By means of the study of contact behavior between the roller/guideway and roller/slider, roller type linear guideways can improve the machining accuracy. The goal of this paper is to construct the fatigue life model of the linear guideway, with the help of the contact mechanics of rollers. In beginning, the analyses of the rigidity of a single roller compressed between guideway and slider was conducted. Then, the normal contact pressure of linear guideways was obtained by using the superposition method, and verified by the FEM software (ANSYS workbench). Finally, the bearing life theory proposed by Lundberg and Palmgren was used to describe the contact fatigue life.

Life Prediction Based on Transient Dynamics Analysis of Van Semi-trailer with Air Suspension System

The early fatigue damage in the van-body of the semi-trailer is often caused by the unique mechanical characteristics and the dynamic impact of the loads.The traditional finite element method with static strength analysis cannot support the fatigue design of van-body;thus,the dynamics analysis should be adopted for the endurance performance.The accurate dynamics model to describe the transient impacts of all kinds of uneven road and the proper system transfer functions to calculate the load transfer effects from tire to van-body are two critical factors for transient dynamics analysis.In order to evaluate the dynamic performance,the dynamics model of the trailer with the air suspension is brought forward.Then the analysis method of the power spectral density （PSD） is set up to study the transient responses of the road dynamic impacts.The transient responses transferred from axles to van-body are calculated,such as dynamic stress,dynamic RMS acceleration,and dynamic load factors.Based on the above dynamic responses,the fatigue life of van-body is predicted with the finite element analysis （FEA） method.Applying the test parameters of the trailer with air suspension,the simulation system with Matlab/Simulink is constructed to describe the dynamic responses of the impacts of the tested PSD of the vehicle axles,and then the fatigue life is predicted with FEA method.The simulated results show that the vibration level of the van-body with air suspension is reduced and the fatigue life is improved.The real vehicle tests on different roads are carried out,and the test results validate the accuracy of the simulation system.The proposed fatigue life prediction method is effective for the virtual design of auto-body.

A Life System Tuning Model

OBJECTIVE: To establish a "life system tuning model", which will provide theoretical and methodological basis to solve various medical problems such as the diagnosis and treatment of complex diseases. METHODS: First of all, by using the approaches of systems biology, bioinformatics, and systems engineering, we set DNA as the center of this model, which severs as a bridge linking the characteristics of a disease with the pharmacological properties of the treating medicine. Secondly, the model shows how to employ molecular markers to dissect the pharmacological property of the drug, and the relation between the pharmacological property of the drug and its clinical administration.Also demonstrates how to discover therapeutic targets and to develop targeted medicine based on the biochemical features of the patients, which reflect their physiological and pathological body environment. Finally, the model uses systems biology data to determine molecular mechanisms underlying the disease and subtype, then employ precision methods to adjust the function of some master molecules. RESULTS: Based on the genetic information, this model integrates the diagnostic information from Western medicine and the disease pattern classification of TCM that is generated from the four diagnostic methods of "inspection, auscultation and olfaction, inquiry and pulse-taking and palpation". This model also integrates various disease intervention approaches including physical methods, chemical methods, and psychological methods. CONCLUSIONS: The establishment of this model provides a basis for personalized treatment of disease using various methods, for the protection and exploration of various natural resources used in TCM, and for the standardization of TCM.

Design and Implementation of the Life Meteorological Index Forecasting System of Wuhu City

Based on the domestic and foreign related research methods, the life meteorological index forecasting system of Wuhu City was compiled using database and network as well as computer language. The system realized the automation process for the generation of life index forecasting products from local situation of Wuhu City and forecasting data, which could get the latest service products dispensing with manual intervention. The development of the system not only made the operation process of the life meteorological index of Wuhu City more time-saving and efficient, but also made the results more scientific and rigorous.

Inference and optimal design on step-stress partially accelerated life test for hybrid system with masked data

Under Type-Ⅱ progressively hybrid censoring, this paper discusses statistical inference and optimal design on stepstress partially accelerated life test for hybrid system in presence of masked data. It is assumed that the lifetime of the component in hybrid systems follows independent and identical modified Weibull distributions. The maximum likelihood estimations(MLEs)of the unknown parameters, acceleration factor and reliability indexes are derived by using the Newton-Raphson algorithm. The asymptotic variance-covariance matrix and the approximate confidence intervals are obtained based on normal approximation to the asymptotic distribution of MLEs of model parameters. Moreover,two bootstrap confidence intervals are constructed by using the parametric bootstrap method. The optimal time of changing stress levels is determined under D-optimality and A-optimality criteria.Finally, the Monte Carlo simulation study is carried out to illustrate the proposed procedures.

A Life Evaluation System and its Application to Mining Machinery Equipment

Based on analyzing the mining equipment life evaluation theoretical system, the equipment life evaluation target system of the mining machinery is put forward taking the economic life, security life, reliability life and technical life as the targets. Then, the structure and model of the mining equipment life evaluation system are established and prepared for the realization of the system theoretically. Taking hydraulic support as the research object, the life evaluation system of hydraulic support is established and practice shows that the life evaluation system is feasible.

轨道交通车辆车门系统生命周期环境效益评价

为了推动轨道交通车辆绿色制造的进程,以车门系统为研究对象,建立生命周期模型,构建环境效益评价指标体系,评价车门系统生命周期生产、运输、使用、废弃物处理阶段的主要环境影响,探究电力能源结构替代和焊接工艺变化对车门系统生命周期的环境影响。结果表明:车门系统生命周期不同阶段的环境影响从大到小的排序为生产阶段、废弃物处理阶段、使用阶段和运输阶段;环境影响评价指标从大到小依次为化石能源消耗潜值、温室气体排放潜值和环境酸化潜值;减少生产阶段和废弃物处理阶段的化石能源消耗和温室气体排放有助于产品生命周期环境效益提升;生产阶段中通过减少火电占比,优化电力结构,全球变暖潜值、化石能源消耗潜值和环境酸化潜值可分别降低38.96%、38.90%、38.86%;采用气体金属弧焊工艺替代保护性金属弧焊工艺,全球变暖潜值、化石能源消耗潜值和环境酸化潜值可分别降低64.71%、58.94%、59.85%。

设计介入社区更新驱动价值创造的可持续策略探讨

作为当前城市更新战略的重要依托,社区更新既要关注物质空间营造,也要响应基层治理的需求,因此设计介入社区更新需要探索系统性介入的可持续策略,从而助力社区复合价值创造。文章结合“制度—生活”的分析范式,解析了社区治理中制度和生活双向互动的机制,然后结合设计价值体系,分析了设计介入社区驱动价值创造的逻辑。从扩充价值定义、丰富设计产物、拓展价值内容等层面构建了设计介入驱动社区价值创造的途径,并形成了从问题解决到意义构建的全过程。对应上述途径,设计在介入社区更新实践中可通过构建“制度—设计—生活”的共参平台、参与社区公共领域全链路营造、跨专业融合协作等策略,助力空间营造和基层治理同步推进,从而在社区更新中发挥设计的价值驱动和创新作用。

Quality of Life in Women with Endometriosis Pelvic Pain Treated with the Levonorgestrel-Releasing Intrauterine System

Objective: To evaluate the quality of life in patients with endometriosis pelvic pain before and after the application of the levonorgestrel-releasing intrauterine system (LNG-IUS). Design: Open non-comparative study. Setting: Obstetrics and Gynecology Hospital at Monterrey, Mexico. Sample: 29 women aged 18 to 40 years with pelvic pain associated with endometriosis confirmed by laparoscopy. Methods: After laparoscopy but before LNG-IUS insertion (basal visit) and 6 months afterwards, modified Endometriosis Health Profile (EHP-30) was applied. Main outcomes measures: Size of change of questionnaire scores, need of additional analgesic therapy and adverse effects. Statistical Analysis: Differences in the questionnaire scores before and after intervention were analyzed by Student t-test. Results: Final analysis set included 29 women aged 31.7 ± 4.7 years years. The ASRM surgical staging of endometriosis was mild in 19.3 moderate in 13.7 and severe in 76% of the patients. The general perception of quality of life improved from 52 at baseline to 98% at six months (p < 0.001). Adverse events were mild in nature, 19 patients reported no adverse events during the study (65.5%). Two patients (6.9%) required the use of concomitant therapy with non-steroidal analgesics for relief of pain. Conclusion: The application of LNG-IUS in patients with pelvic pain associated with endometriosis improved significatively all aspects related with quality of life as measured with Endometriosis Health Profile (EHP-30). We concluded that LNGIUS may be an effective and convenient therapeutic alternative for the management of pain associated with endometriosis.

我国农村居民生活质量评价研究

为更好地衡量当前我国农村居民实际生活水平,本文构建了评价指标体系,运用主客观结合的组合赋权法对2013—2023年我国农村居民生活质量开展评价研究。研究结果表明,党的十八大以来,随着我国农村贫困人口全部脱贫,乡村振兴全面推进,农村生活条件显著改善,农村居民生活实现历史性跨越。但农村居民生活质量持续改善仍存在短板弱项,需从夯实物质基础、改善生活环境、提升公共服务、强化精神文化建设等方面持续提升,更好满足人民群众对美好生活的向往。

标识性概念与中国自主法学知识体系的构建

标识性概念是自主法学知识体系构建的基础,也是自主法学知识体系得以型构的动力。在习近平法治思想中,人民至上、美好生活、社会公平正义等范畴凝练了法律本体、法律内容、法律价值的概念表达,从而成为代表新时代中国特色社会主义法治理论的标识性概念。人民至上将抽象的人民还原为具体的、现实的个人,将全体社会成员的权利、利益作为保护的对象,体现了社会主义法律制度的人民性、人道性、包容性;美好生活作为中国新时代法律的基本面向,美好生活权代表着以民生权为核心内容的权利束,规制着法律的内容及其发展;社会公平正义是超越个人应得、社会公平的复合型正义,它不仅及于主体、制度之间的公平,还包括城乡、地域以及事项上的公平。机会公平作为社会公平正义的内容之一,是与权利公平有所不同的价值理念,由此也使社会公平正义这一标识性概念的内涵愈益广泛。

System Dynamics Approach in LCA for PET-Renewable Raw Materials Impact

It has been shown that system dynamics and life-cycle analysis together provide an analytical tool to study different impacts between variables in decision-making process. This paper presents an application of this approach toward to a plastic material of quotidian use, considering both, a production chain using renewable resources and petrochemical production of Polyethylene Terephthalate, used as a beverage bottle application, and showing its impacts to the system when production replacement of non-renewable resources is allowed. We have already studied the substitution between different materials: glass and aluminum.

Thoughts of a Medical Doctor about the Life Periods of Our Earth and the Evolution

The author thinks that the endless and timeless Universe is a permanent substance and energy flow as well as motion of celestial systems and bodies. Celestial bodies may have physical and biological life. Our Earth has both lives which can be divided into different periods of time. Its physical life can mainly be characterized by the atomic evolution, sterility, appearance of water and abiotic chemical reactions. Essence of the biological life is the existence of the living unit. Biological life of our Globe started with the first living unit/microorganism which began to influence on its environment which is a closed system for substance, flora, creature and man but not for hit of celestial bodies and for arrival of different kinds of energy from the space as well as for radiation of heat. The biological life of our Earth can be divided into four parts: before photosynthesis, before mankind, before 1778 and after the industrial revolution.

典型钢桥面铺装体系生命周期碳足迹分析

为了量化钢桥面铺装体系的碳排放量,应用基于过程的生命周期评价方法分析了钢桥面铺装体系的生命周期碳足迹.从材料生产、施工建造、运营管理、维修养护、废弃处置和运输6个过程构建了钢桥面铺装体系碳排放的生命周期清单数据库,采用国际平整度指数建立铺装层行驶质量衰减下的碳排放预估模型,利用SMUO仿真软件进行交通延误仿真获取相关参数以建立交通延误的碳排放模型,建立了相应的碳足迹量化框架和模型,同时对下层EA(环氧)+上层SMA(沥青玛蹄脂)典型铺装体系进行了实例分析.结果表明,维修养护和运营管理阶段贡献了碳排放总量的近80%,交通延误导致的额外碳排放约达到了碳排放总量的24%,固化剂、喷砂除锈等材料或施工工艺也分别贡献了碳排放总量的8.11%和5.42%.

LCA in Environmental Management Systems—Results of Individual Interviews with Selected Enterprises from Poland and Sweden

Life Cycle Assessment (LCA) is an analytical tool used for the environmental optimization of products and services within the entirety of its life cycle. ISO 14040 recommends use of the technique in numerous areas of environmental management such as in designing for the environment, eco-labelling, environmental communications and the assessment of the effects of environmental activities. Despite being theoretically feasible, certain applications of the ecological assessment of a life cycle such as the possibility of identification and evaluation of environmental aspects with the use of LCA are, in practice, still new to many environmental managers. With its strong points, the technique seems to be a valuable tool, especially in the context of apparent concepts of Product-Oriented Environmental Management Systems (POEMS). In order to verify the hypothesis, the author decided to verify the level of use of LCA in the area of identification and assessment of environmental aspects in selected organizations. Therefore, questionnaire interviews were conducted with representatives of selected Polish and Swedish enterprises who, at the time of the interview, had certified environmental management systems. The organizations were analyzed with respect to applied methods and techniques used for identification and assessment of environmental aspects as well as the degree of use of LCA both in this respect and in other areas of environmental management. This paper will present the results of this research and conclusions.