The aim of this paper is to analyze the potential reasons for the safety failure of batteries for new-energy vehicles.Firstly,the importance and popularization of new energy batteries are introduced,and the importance...The aim of this paper is to analyze the potential reasons for the safety failure of batteries for new-energy vehicles.Firstly,the importance and popularization of new energy batteries are introduced,and the importance of safety failure issues is drawn out.Then,the composition and working principle of the battery is explained in detail,which provides the basis for the subsequent analysis.Then,the potential impacts of factors such as overcharge and over-discharge,high and low temperature environments,internal faults,and external shocks and vibrations on the safety of the batteries are analyzed.Finally,some common safety measures and solutions are proposed to improve the safety of new energy batteries,in hopes of improving the safety of batteries for new-energy vehicle.展开更多
This paper,based on the questionnaire,deduces the causes of pragmatic failure which are summarized into four:The different value orientation between the two cultures,consisting individualism versus collectivism,power ...This paper,based on the questionnaire,deduces the causes of pragmatic failure which are summarized into four:The different value orientation between the two cultures,consisting individualism versus collectivism,power distance,connotation versus denotation,and orientation towards time,negative transfer of equivalent structures and behaviors,insufficient or improper teaching and the scarcity of universal knowledge for communication.展开更多
Objective:To determine the frequency of risk factors of congestive cardiac failure in a tertiary care hospital of Peshawar.Methods:This retrospective observational study was conducted in department of Cardiology,Postg...Objective:To determine the frequency of risk factors of congestive cardiac failure in a tertiary care hospital of Peshawar.Methods:This retrospective observational study was conducted in department of Cardiology,Postgraduate Medical Institute,Lady Reading Hospital Peshawar,from March 2005 to September 2007.Relevant information regarding the risk factors of congestive cardiac failure were recorded on questionnaire prepared in accordance with the objectives of the study.Results:1 019 patients with established diagnosis of cardiac failure (based on clinical findings and relevant investigations) were included.Out of total sampling 583 (57.12%) were males and 436(42.78%) were females.The age range of the patients was from 6 years to 82 years with mean age of 48.5 years and mode of age was 45 years.The distribution of causative factors of CCF was:ischemic heart disease(IHD) 36.31%,hypertension 26.30%,dilated cardiomyopathy 10.10%,obstructve and restrictive cardiomyopathies 5.39%,valvular heart diseases(VHD) 9.32%,congenital heart disease like ventricular septal defects(VSD) 4.41%,atrial septal defects(ASD) 0.58%,atrial fibrillation (AF) 2.25%,constrictive pericardidtis 1.07%.Pericardial effusion 0.68%,chronic obstructive pulmonary disease and pulmonary hypertension 1.47%,thyrotoxicosis 0.68%,complete heart block 0.29%and paget disease in 0.09%cases.Conclusion:Ischemic heart disease,hypertension,cardiomypathies,valvular heart disease and congenital heart disease are major contributor to CCF in our patients.展开更多
This paper presents reliability and availability analyses of a model representing a system having one robot and n-redundant safety units with common-cause failures. At least k safety units must function successfully f...This paper presents reliability and availability analyses of a model representing a system having one robot and n-redundant safety units with common-cause failures. At least k safety units must function successfully for the robot system success. The robot and other failure rates and the partially failed system repair rates are assumed constant and the failed robot-safety system repair time is assumed arbitrarily distributed. Markov and supplementary variable methods were used to perform mathematical analysis of this model. Generalized expressions for state probabilities, system availabilities, reliability, mean time to failure, and variance of time to failure are developed. Plots of some resulting expressions are shown.展开更多
针对传统Petri网(P/T系统)无法根据后继标识确定系统失效部位的问题,采用着色Petri网(Colored Petri Net,CPN)建立动车组列控车载子系统的故障传播模型。首先,通过CPN与传统Petri网理论的对比说明采用CPN建模的可行性。其次,根据车载子...针对传统Petri网(P/T系统)无法根据后继标识确定系统失效部位的问题,采用着色Petri网(Colored Petri Net,CPN)建立动车组列控车载子系统的故障传播模型。首先,通过CPN与传统Petri网理论的对比说明采用CPN建模的可行性。其次,根据车载子系统的结构组成及工作模式建立故障树模型,并通过Petri网描述故障树逻辑门事件之间的逻辑关系,给出故障树的Petri网表示方法,建立车载子系统的P/T系统模型;进一步根据CPN理论确定托肯染色方法、权函数等模型参数,将P/T系统转化为着色网系统,并举例说明后继标识的计算规则。最后,通过与传统Petri网推理及故障识别过程的对比,证明了采用CPN分析系统故障机理的正确性及在故障识别过程中的高效性。所提方法可为车载子系统的故障识别提供一定依据。展开更多
文摘The aim of this paper is to analyze the potential reasons for the safety failure of batteries for new-energy vehicles.Firstly,the importance and popularization of new energy batteries are introduced,and the importance of safety failure issues is drawn out.Then,the composition and working principle of the battery is explained in detail,which provides the basis for the subsequent analysis.Then,the potential impacts of factors such as overcharge and over-discharge,high and low temperature environments,internal faults,and external shocks and vibrations on the safety of the batteries are analyzed.Finally,some common safety measures and solutions are proposed to improve the safety of new energy batteries,in hopes of improving the safety of batteries for new-energy vehicle.
文摘This paper,based on the questionnaire,deduces the causes of pragmatic failure which are summarized into four:The different value orientation between the two cultures,consisting individualism versus collectivism,power distance,connotation versus denotation,and orientation towards time,negative transfer of equivalent structures and behaviors,insufficient or improper teaching and the scarcity of universal knowledge for communication.
文摘Objective:To determine the frequency of risk factors of congestive cardiac failure in a tertiary care hospital of Peshawar.Methods:This retrospective observational study was conducted in department of Cardiology,Postgraduate Medical Institute,Lady Reading Hospital Peshawar,from March 2005 to September 2007.Relevant information regarding the risk factors of congestive cardiac failure were recorded on questionnaire prepared in accordance with the objectives of the study.Results:1 019 patients with established diagnosis of cardiac failure (based on clinical findings and relevant investigations) were included.Out of total sampling 583 (57.12%) were males and 436(42.78%) were females.The age range of the patients was from 6 years to 82 years with mean age of 48.5 years and mode of age was 45 years.The distribution of causative factors of CCF was:ischemic heart disease(IHD) 36.31%,hypertension 26.30%,dilated cardiomyopathy 10.10%,obstructve and restrictive cardiomyopathies 5.39%,valvular heart diseases(VHD) 9.32%,congenital heart disease like ventricular septal defects(VSD) 4.41%,atrial septal defects(ASD) 0.58%,atrial fibrillation (AF) 2.25%,constrictive pericardidtis 1.07%.Pericardial effusion 0.68%,chronic obstructive pulmonary disease and pulmonary hypertension 1.47%,thyrotoxicosis 0.68%,complete heart block 0.29%and paget disease in 0.09%cases.Conclusion:Ischemic heart disease,hypertension,cardiomypathies,valvular heart disease and congenital heart disease are major contributor to CCF in our patients.
文摘This paper presents reliability and availability analyses of a model representing a system having one robot and n-redundant safety units with common-cause failures. At least k safety units must function successfully for the robot system success. The robot and other failure rates and the partially failed system repair rates are assumed constant and the failed robot-safety system repair time is assumed arbitrarily distributed. Markov and supplementary variable methods were used to perform mathematical analysis of this model. Generalized expressions for state probabilities, system availabilities, reliability, mean time to failure, and variance of time to failure are developed. Plots of some resulting expressions are shown.
文摘针对传统Petri网(P/T系统)无法根据后继标识确定系统失效部位的问题,采用着色Petri网(Colored Petri Net,CPN)建立动车组列控车载子系统的故障传播模型。首先,通过CPN与传统Petri网理论的对比说明采用CPN建模的可行性。其次,根据车载子系统的结构组成及工作模式建立故障树模型,并通过Petri网描述故障树逻辑门事件之间的逻辑关系,给出故障树的Petri网表示方法,建立车载子系统的P/T系统模型;进一步根据CPN理论确定托肯染色方法、权函数等模型参数,将P/T系统转化为着色网系统,并举例说明后继标识的计算规则。最后,通过与传统Petri网推理及故障识别过程的对比,证明了采用CPN分析系统故障机理的正确性及在故障识别过程中的高效性。所提方法可为车载子系统的故障识别提供一定依据。
