• Journal of Applied Reliability
• /
• v.14 no.1
• /
• pp.59-70
• /
• 2014

The requirements of reliability verification for new products and technology are increasing more and more in accordance with the trend of climate change prevention and GHG reduction technology, functional skills. SCA(Swirl Control Actuator) is the important part of a car intake manifold system. This device generates swirl that is mixing the fuel and air into the engine combustion chamber. This is to improve output for engine and reduce the emission for exhaust. In this article reliability assessment criteria for swirl control actuator for automobiles are established in terms of basic HALT and life time test.

• Journal of the Korean Society of Manufacturing Technology Engineers
• /
• v.24 no.5
• /
• pp.521-529
• /
• 2015

Owing to a reliance on imported products from Europe and Japan, the use of logistics equipment with poor energy efficiency coupled with high maintenance costs can lead to high operating costs for some domestic logistic centers. To lower their operating costs, the logistic centers use motorized roller conveyors. In order to commercialize this process, it is necessary to establish the test criteria and assess the reliability of the process. Currently, there exists no standard verification method to test the reliability of motorized roller conveyors. In this study, we propose reliability assessment criteria for a: i) reliability test, ii) environmental test, iii) safety test, and iv) lifetime test.

• International Journal of Naval Architecture and Ocean Engineering
• /
• v.11 no.1
• /
• pp.11-21
• /
• 2019

In product design, the initial design stage is being increasingly emphasized because it significantly influences the successive product development and production stages. However, for larger and more complex products, it is very difficult to accurately predict product reliability in the initial design stage. Various design methodologies have been proposed to resolve this issue, but maintaining reliability while exploring design alternatives is yet to be achieved. Therefore, this paper proposes a methodology for conceptual design considering reliability issues that may arise in the successive detailed design stages. The methodology integrates the independency of axiomatic design and the hierarchical structure of failure mode, effects, and criticality analysis (FMECA), which is a technique widely used to analyze product reliability. We applied the proposed methodology to a liquefied natural gas fuel gas supply system to verify its effectiveness in the reliability improvement of the design process.

• Journal of Applied Reliability
• /
• v.5 no.2
• /
• pp.273-287
• /
• 2005

Accelerated life test models and procedure are developed to assess the reliability of Refrigerator door switch. The main function of door switch is to operate bulb lamp and fan motor in the refrigerating room. The accelerated life test method and test equipments are developed using the relationship between stresses and life characteristics of the products. Using the developed accelerated life test method, the parameters of the ALT model and life time distribution are estimated and the reliability of the Door S/W at use condition if assessed. The proposed accelerated life test method and procedure may be extended and applied to testing similar kinds of products to reduce test time and costs of the tests remarkably.

• The Korean Journal of Applied Statistics
• /
• v.22 no.1
• /
• pp.163-170
• /
• 2009

The purpose of this article is to measure the level of insurance industry's social cognition based on the university students' survey questionnaire. For this, this study analyzes the cognition of students on the level of social reliability, the causes of low reliability, and the measures of enhancing the reliability level about insurance industry. For the analysis of survey questionnaire, partially ranked data analysis was employed. The results show that most students recognize that the reliability of insurance industry is lower than that of other financial industry such as banks and securities firms. The main reason for this low reliability is the lack of sales forces' specialty, the complexity of insurance products and contracts, and negative media release about insurance industry. To enhance the social reliability level of insurance, establishment of the future insurance image is essential, and that can be achieved through strengthening the insurance education and public relations and simplifying insurance products and contracts.

• Journal of Applied Reliability
• /
• v.10 no.4
• /
• pp.251-263
• /
• 2010

Modelling for failures is important for reliability analysis since failures of products such as automobiles occur as both time and usage progress and the results from the proper analysis of the two-dimensional data can be used for establishing warranty assurance policy. Hence, in this paper general issues which concern modelling failures are discussed, and both one-dimensional approaches and two-dimensional approaches to two-dimensional data are investigated. Finally non-parametric approaches to two-dimensional data are presented as a means of exploratory data analyses.

• Proceedings of the Korean Statistical Society Conference
• /
• 2002.11a
• /
• pp.129-132
• /
• 2002

네트워크를 설계하거나 평가하는데 있어 중요한 문제 중 하나는 그 네트워크를 구성하는 요소들간의 상대적 중요도(importance)에 관한 문제이다. 이런 중요도를 나타내는 여러 가지 측도들 중 하나인 Joint Reliability Importance(JRI)는 Hong & Lie(1993)에 의해 소개되었으며, 네 가지 파생된 서브그래프의 신뢰성을 구하여 JRI를 계산하는 방법이 제시되었다. 본 연구에서는 minimal path set을 이용하여 파생되는 서브 그래프 신뢰성 계산에서의 중복되는 계산과정을 줄임으로써 JRI를 보다 효율적으로 구하는 방법을 제시하고자 한다.

• Proceedings of the Korean Society of Precision Engineering Conference
• /
• 1997.04a
• /
• pp.169-173
• /
• 1997

In this paper, auto measuring system for evaluating sensing reliability of infrared temperature sensors is developed. A developed system is composed of temperature controller, measuring sysytem and operating S/W. A constant temperature control of a chamber is accomplished by multi-heater using PI control. It is shown that the control resulte of temperature are well followed to the desired temperature value. The developed untegrated measuring system will increase reliability and productivity of products.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 1998.10a
• /
• pp.210-215
• /
• 1998

In this paper, systemaic approach is studied about assembility and disassemblility of parts of the gear system in order to reduce the assembly cost, and to disassemble products easily which is possible to recycle the parts. That is, an estimation of disassembly and assembly with considering of reliability life. In this study, we use symbolic chart method for an economic model for optimal disassembly and assembly.

• Journal of Industrial Technology
• /
• v.29 no.A
• /
• pp.27-36
• /
• 2009

Reliability plays a pivotal role in products safety and quality. DoD RIAC recently developed a new reliability prediction methodology, $217Plus^{TM}$, for electronic systems. It officially replaces the well-known MIL-HDBK-217 and is expected to be widely used. Although theoretic study about $217Plus^{TM}$ and its application towards field systems seem to be attractive, it is also desirable to understand the general background of its development. In this paper, we performed a historical review of the arenas related to reliability prediction. Due to the vast of materials, our scope was limited to the development of $217Plus^{TM}$. We first reviewed Rome Laboratory and RIAC. We then explained the development course of reliability methods, MIL-HDBK-217, PRISM, and 217-Plus. This review will form not only a good understanding of the methodology but a basis for future study. We conclude this study with provision of future research areas.