• Journal of Applied Reliability
• /
• v.9 no.1
• /
• pp.1-12
• /
• 2009

BLDC motors are stored in the devices such as CD-RW, COMBO, DVD-ROM and CD-ROM. It is indispensable to establish reliability assessment criteria for BLDC motors, especially in the world where IT grows rapidly. In this article, reliability certification procedure is given. The reliability certification procedure consists of two separate tests such as quality certification test and lifetime test. The former quality certification test comprises general performance test and environmental test. Items which pass the test undergo lifetime test which guarantees the extent of mean lifetime with certain confidence.

• Journal of Applied Reliability
• /
• v.9 no.2
• /
• pp.93-106
• /
• 2009

GPS(Global positioning system) system is widely used in artificial satellite, ground controlled approach system as well as in end-user environment such as in the automobile. It is exposed to a very diverse environment and consists of many complicated components and therefore needs careful approach to the enhancement of reliability of the item. In this article reliability standards for the GPS system are established in terms of quality certification tests and failure rate tests.

• Journal of Applied Reliability
• /
• v.18 no.3
• /
• pp.208-212
• /
• 2018

Purpose: The three Vs of volume, velocity and variety are commonly used to characterize different aspects of Big Data. Volume refers to the amount of data, variety refers to the number of types of data and velocity refers to the speed of data processing. According to these characteristics, the size of Big Data varies rapidly, some data buckets will contain outliers, and buckets might have different sizes. Correlation plays a big role in Big Data. We need something better than usual correlation measures. Methods: The correlation measures offered by traditional statistics are compared. And conditions to meet the characteristics of Big Data are suggested. Finally the correlation measure that satisfies the suggested conditions is recommended. Results: Mutual Information satisfies the suggested conditions. Conclusion: This article builds on traditional correlation measures to analyze the co-relation between two variables. The conditions for correlation measures to meet the characteristics of Big Data are suggested. The correlation measure that satisfies these conditions is recommended. It is Mutual Information.

• Journal of Applied Reliability
• /
• v.10 no.1
• /
• pp.11-24
• /
• 2010

Lighting industry is rapidly being developed as the ubiquitous society based on sensor network emerges. This kind of paradigm shift brings the society convergence of technologies which leads to smart lighting system as well as the integration of interior and sensibility control. However, standards for sensors have not been firmly established, and problems related to quality and malfunction have been brought up, thereby calling for careful approach to the enhancement and assessment of reliability of the item. In this article reliability assessment criteria for sensor module for lighting fixtures is established in terms of performance assessment criterion and reliability assessment criterion.

• Proceedings of the Korean Society for Rock Mechanics Conference
• /
• 2001.10a
• /
• pp.25-36
• /
• 2001

록볼트의 작용효과는 지반이 굴착되어 안정화되는 초기 1달간이 가장 중요하고 품질관리 문제는 지반조건에 따라 부식에 대한 문제가 있으나, 기존의 전면접착형 록볼트의 경우도 작업여건상 그 확실성은 떨어지는 것이 현실이다. 또한 작업이 시간소모가 크고, 볼트의 지지효과도 충진재가 고결되어야 발효되는 약점을 갖고 있어, 일본, 말레이시아, 유럽 등에서 전면 마찰형 즉시 지보기능이 가능한 Swellex Bolt를 영구지보재로 사용하고 있는 경향이 있다. 기존의 전면 접착형 SN Bolt(이형철근)로써 Grouting 몰탈볼트와 Cem Bolt로 설계된 장대·대단면 도로터널 지보재를 현대식 Swellex Bolt로 대체 설계변경이 가능한 것인지에 대하여 볼트의 지지력 시험(Pullout Test), 볼트재질의 내구성 연구 및 설계변경에 따른 수치해석 등을 실시하여, 볼트로써 지지력을 확인하고, 재질의 안전성을 조사한 후 시공 사이클 타임을 줄이며, 견고하고 시공성이 우수한 Swellex Bolt로의 설계변경을 제안하게 되었다.

• Journal of Applied Reliability
• /
• v.11 no.1
• /
• pp.17-30
• /
• 2011

Many domestic manufacturers make reflectors for Lamps of BLU(back light units). However, color change and parting occur as a result of diverse usage environment. Therefore, many of the manufacturers are reluctant in R&D investment of reflectors for Lamps of BLU. Hence, in this article reliability assessment criteria for reflector for lamp of BLU are established in terms of performance test, environment test and life test.

• Journal of Applied Reliability
• /
• v.16 no.1
• /
• pp.71-77
• /
• 2016

Purpose: Root cause analysis (RCA) refers to any systematic process that identifies the causes that contribute to a focus event. The immediate cause of a focus event is often a symptom of underlying causes and may not truly identify the root causes that should be identified and addressed. Currently many RCA tools are available. Different investigators use different RCA tools on different issues. No standardized or commonly agreed way to analyse root causes exists. The purpose of this study is to propose the methodology of RCA process commonly useable for various issues. Methods: The methodology of RCA process is produced based on the hybrid RCA tools. The effectiveness assessment matrix of actions through the root cause candidates is presented. Results: No single RCA technique proposed has so far covered all necessary aspects. A hybrid approach which combines the best features of various techniques is proposed. The effectiveness assessment matrix helps us to identify the root cause to correct or eliminate system vulnerabilities effectively. Conclusion: This hybrid approach and effectiveness assessment matrix can provide guidance of RCA process across many industries and situations.

• Journal of Applied Reliability
• /
• v.8 no.1
• /
• pp.29-37
• /
• 2008

The technology of North Korea has not reached the modem level even though it has economic potential. Standardization and quality control have comprehensively prevailed in South Korea since the 1970s, which is considered to have been based of quality improvement. In the course of an active interchange between South and North, it is necessary to grasp the phenomenon on the quality and reliability control of North Korea. This study will put its relevant terms in order and make a comparison between specifications of North Korea and South Korea in the reliability test plans.

• Journal of Applied Reliability
• /
• v.9 no.3
• /
• pp.259-274
• /
• 2009

Printed circuit boards for RAM are widely used in modern electronics such as computers, artificial satellites and consumer durables. They are exposed to a very diverse environment and consists of many complicated components and therefore needs careful approach to the enhancement and assessment of reliability of the item. In this article reliability standards for PCBs for RAM are established in terms of quality certification tests and failure rate tests.

• Journal of Applied Reliability
• /
• v.9 no.3
• /
• pp.219-231
• /
• 2009

Power light emitting diodes(LED) for lighting fittings are so much environment-friendly, highly reliable and consume less energy that they are widely used at home and in industries such as electronics, telecommunications and industrial machineries. However, they are exposed to a very diverse environment and consists of complex components and, therefore needs careful approach to the enhancement and assessment of reliability of the item. In this article reliability assessment criteria for LED are established in terms of performance assessment test, reliability assessment test and accelerated test.