• KSCE Journal of Civil and Environmental Engineering Research
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• v.26 no.1A
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• pp.21-33
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• 2006

The reliability analysis can be conducted more effectively by formulating the stochastic finite element method suitable for the reliability theory about the cable stayed bridge. After conducting the initial equilibrium analysis of the cable stayed bridge, the program which can conduct the linear and nonlinear stochastic finite element analysis using the perturbation method and the reliability analysis considered to the correlation of the random variable is developed. Using the results of this program about the cable stayed bridge, the characteristic of the node displacement, element force and cable tension according to the correlation of the random variable is investigated quantitatively. Also the reliability index and the failure probability are examined by the compounding the correlation of the random variable.

• Journal of Advanced Navigation Technology
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• v.28 no.2
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• pp.216-224
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• 2024

This paper presents a method for analyzing the reliability of hardware electronic equipment, taking into account failures caused by radiation. Traditional reliability analysis primarily focuses on the wear out failure rate and often neglects the impact of radiation failure rates. We calculate the wear out failure rate through physics of failure analysis, while the radiation failure rate is semi-empirically estimated using the Verilog Fault Injection tool. Our approach aims to ensure reliability early in the development process, potentially reducing development time and costs by identifying circuit vulnerabilities in advance. As an illustrative example, we conducted a reliability analysis on the ISCAS85 circuit. Our results demonstrate the effectiveness of our method compared to traditional reliability analysis tools. This thorough analysis is crucial for ensuring the reliability of FPGAs in environments with high radiation exposure, such as in aviation and space applications.

• Journal of the Korean Society for Railway
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• v.20 no.4
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• pp.458-465
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• 2017

The railway signaling system, which controls the course of trains and the distance between trains, is a safety critical system of the railway system because derailment or collision of trains can occur if unsafe failure is generated by any fault. The international standards of reliability, availability, maintainability, and safety of railway applications require that the safety of functions be guaranteed in safety critical systems; system reliability and safety are quantitatively estimated and demonstrated by the failure rates of devices. The development of technology has accelerated the development of railway signaling systems. Existing devices, which have already been verified as to their safety, are applied with special user requirements to reflect the new operation scenario. It is found that the reliability and safety of the devices are different depending on individual application. Therefore, the reliability of the railway signaling system must be considered while complying with the international standards; this requires that the initial failure rate be estimated and demonstrated using fault data gathered over several years. This paper shows a method for demonstrating the initial estimated failure rate and suggests a fault data collection method and an overall process that is based on probability.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
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• v.4 no.1
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• pp.142-163
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• 1993

A 8 year old boy with problems of hyperactivity, impulsivity received playpsychotherapy. Through the detailed examination of their contents and group supervision of play therapy session, common mistakes novice therapist make frequently and tasks in the initial phase of play psychotherapy are illustrated. Therapist's personality and anxiety frequently interferes therapeutic processes. Common mistakes therapist makes during initial phase of play therapy are ; therapist's over-enthusiasm, overinvolvement or non-responsiveness, premature or inappropriate interpretation and direct connection of play theme to reality. It is utmost important for the therapist to make positive and trusting relationship with the patient in the initial phase of the therapy. In order to do so therapist must accept the patient as he is, permit the patient takes his leads. And as a result, the Patient can go through corrected developmental experience. In conclusion, it is a therapist's main task to establish relationship.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.15 no.2
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• pp.261-270
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• 2002

The use of ANN is appropriate to computerize the information and knowledge used in the preliminary design stage where it lacks of formality of representation of designers' experience and intuition. Considering that there exists very little design information in preliminary design stage to start with, the ANN model for this stage must be designed to have input much less than output. However, this situation usually causes various problems such as in teaming time, convergence and reliability of solutions. To address this problem, this paper proposes multi-level neural networks lot progressive structural design considering that all the design information can not be obtained at a time but we growing gradually. The use of multi-level networks developed in this paper has been proved its validity by applying it to the preliminary design of cable-stayed bridges.

• Management & Information Systems Review
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• v.33 no.2
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• pp.63-79
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• 2014

This study is based on the previous studies on m-commerce features, found factors that affects reliability and user's intention. After that, it examined how these factors influence the relationship between reliability and user's intention. In addition, this study showed that some factors have different influence on Korean and Chinese users in terms of reliability and user's intention. The main results of this study are as follows: (1) Personal innovation attributed to reliability in both Korea and China. Personal innovation also attributed to user's intention in Korea. (2) Localization, reach ability, security, and convenience had different influence on use and reliability in the two countries. (3) And the influences between reliability and user's intention are all positive both in Korea and China. Based on the result of this empirical study, this study reveal some implications for the firms that running with mobile business in both Korea and China.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.1
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• pp.9-18
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• 2015

Software Reliability Growth Models (SRGMs) are useful for determining the software release date or additional testing efforts by using software failure data. It is not appropriate for a SRGM to apply to all software. And besides a large number of SRGMs have already been proposed to estimate software reliability measures. Therefore selection of an optimal SRGM for use in a particular case has been an important issue. The existing methods for selecting a SRGM use the entire collected failure data. However, initial failure data may not affect the future failure occurrence and, in some cases, it results in the distorted result when evaluating the future failure. In this paper, we suggest a method for selecting a SRGM based on the evaluation goodness-of-fit using partial data. Our approach uses partial data except for inordinately unstable failure data in the entire failure data. We will find a portion of data used to select a SRGM through the comparison between the entire failure data and the partial failure data excluded the initial failure data with respect to the predictive ability of future failures. To justify our approach this paper shows that the predictive ability of future failures using partial data is more accurate than using the entire failure data with the real collected failure data.

• Magazine of the Korea Concrete Institute
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• v.10 no.3
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• pp.153-164
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• 1998

본 연구는 양생온도의 영향에 따른 콘크리트의 장기강도 예측식을 개발하고, 기존에 보고된 데이터를 이용하여 제안식의 신뢰성을 검증하기 위한 것이다. 제안식은 반응률상수 모델을 이용하였으며, 콘크리트의 장기강도에 영향을 미치는 인자로 양생온도에 따른 확산장벽의 효과를 고려하였다. 제안식을 검증하기위하여 각각의 데이터를 28일 상대강도의비로바꾸어 -0.6~59.7$^{\circ}C$ 범위의 8개의 평균 양생온도에 대해서 회귀분석하였다. 회귀분석을통해 제안식의 온도 영향계수인 반응율상수, 한계강도, 반응지수를 양생온도에 따른 함수식으로 표현하였다. 제안식은 기존의모델식에 비해 신뢰성이 높았으며, 초기재령에서는 기존의 모델식등과 큰 차이를나타내지 않았으나 장기재령으로 갈수록 제안식의 정확도가 크게 높아짐을 알 수 있었다.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.14 no.2
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• pp.97-106
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• 2001

본 연구에서는 트러스 구조물의 이산최적설계를 위해 유전알고리즘(GA)을 적용하였다. 확률론적인 절차를 통해 설계에 필요한 초기 집단을 생성시킨 후, 설계를 개선시키기 위해서 자연선택 및 적자생존의 원리를 적용하였다. 다하중조건 하에서 트러스 구조물의 중량 최소화를 위해 응력 및 변위 제약을 고려하였다. 먼저, 이미 잘 알려진 트러스 구조물에 대해서 GA를 이용하여 얻은 최적해와 기존 문헌들에서 제시하고 있는 값들을 비교함으로써 GA의 신뢰성 및 적용성을 검증하였고, 이러한 신뢰성 검증을 바탕으로 사용성 있는 트러스 구조물의 이산최적설계를 위해 현재 생산중인 강재제원표로부터 부재가 선택되도록 하였다. 강재의 단면으로는 L형강을 사용하였으며, L형강의 강종은 9개의 강종들 (SS 400, SWS 400, SMA 41, SWS 490Y, SWS 520, SMA 50, SWS 570, SMA 58) 중에서 설계자에 의해 자유롭게 선택되도록 하였다.

• Journal of the Korean Vacuum Society
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• v.1 no.2
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• pp.291-297
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• 1992

알루미늄 박막 stripe에 d.c. 전류를 인가하여 electromigration에 의한 결함을 분 석하였다. 6 $\times$ 10-8Torr의 진공동에서 전자빔 증착기를 사용하여 현미경을 유리기판에 $1000AA$의 두께로 알루미늄 박막을 증착하였다. Al/glass 박막의 초기 비저항은 2.7 $\pm$ 0.15($\mu$$\Omega$cm)이였다. 알루미늄 stripe에 electromigration에 의해 양극쪽에 물질 축적영역 (hillocks)과 음극쪽에는 물질 고갈영역(voids)이 형성되었다. SEM, EDAX와 Optical microscope로 hillocks과 voids를 분석하였다. 또한 결함에 대한 SiO2 보호막효과에 대하여 도 분석하였으며, SiO2 보호막에 의하여 Al 박막의 신뢰성은 향상되었다.