• Journal of the Computational Structural Engineering Institute of Korea
• /
• v.18 no.1
• /
• pp.51-59
• /
• 2005

SLSV (single loop single vector) method is to solve the excessive computational cost problem in RBDO (reliability-based design optimization) by decoupling the nested iteration loops. However, the practical use of SLSV method to RBDO case is limited by the instability or inaccuracy of the method since it often diverges or converges to a wrong solution. Thus, in this paper, a new modified SLSV method is proposed. This method improves its convergence capability effectively by utilizing Inactive Design and Active MPP Design together with modified HMV (hybrid mean value) method. The usefulness of the proposed method is also verified through numerical examples.

• Journal of Korean Academy of Nursing Administration
• /
• v.9 no.1
• /
• pp.75-88
• /
• 2003

Purpose : The Purposes of this study was to develop a learning organization measurement for nurses, and to test the validity and reliability of the measurement. Method : This study was conducted through 3 phases -theoretical framework choice, measurement items selection, and the testing of validity and reliability. In order to test reliability and validity of the measurement, data were collected from the 261 nurses, working in the 1 hospital with more 800 beds. The data obtained were analyzed by SPSS for Window program using percentages, Factor Analysis, Cronbach's alpha coefficients. Result : As a result of the study, 2 scales -Learning Organization Building Scale, and Knowledge Management Process Scale- were developed. Learning Organization Building Scale was consisted of 23 items, 5 factors. 5 factors explained 60.26% of the total variance, and the Cronbach's alpha of this scale was .8807. Knowledge Management Process Scale was consisted of 17 items, 4 factors. 4 factors explained 66.14% of the total variance, and the Cronbach's alpha of this scale was .9147. Conclusion : The Study supports the validity and reliability of the scales. Therefore, these scales can be effectively utilized for many researches about Learning organization of Nurse, and Nursing organization in the Hospital Setting.

• Journal of the Institute of Electronics and Information Engineers
• /
• v.52 no.10
• /
• pp.47-55
• /
• 2015

To verify the function of vehicle is becoming more and more difficult because many electronic control units have been embedded in vehicle with development of electronics industry. The reliability of vehicle should be considered above all important because malfunction of vehicle can cause damage of human life. In this paper, defect diagnosis platform based on CAN network is proposed to improve the reliability of vehicle. Reliability of vehicle is significantly increased by adopting the structural test via dedicated test path after manufacturing. Besides, the test cost is reduced because additional test pins are not required.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2002.07a
• /
• pp.32-35
• /
• 2002

The work focuses on the development of a Cu lead-frame with a single-sided adhesive tape for cost reduction and reliability improvement of LOC (lead on chip) package products, which are widely used for the plastic-encapsulation of memory chips. Most of memory chips are assembled by the LOC packaging process where the top surface of the chip is directly attached to the area of the lead-frame with a double-sided adhesive tape. However, since the lower adhesive layer of the double-sided adhesive tape reveals the disparity in the coefficient of thermal expansion from the silicon chip by more than 20 times, it often causes thermal displacement-induced damage of the IC pattern on the active chip surface during the reliability test. So, in order to solve these problems, in the resent work, the double-sided adhesive tape is replaced by a single-sided adhesive tape. The single-sided adhesive tape does net include the lower adhesive layer but instead, uses adhesive materials, which are filled in clear holes of the base film, just for the attachment of the lead-frame to the top surface of the memory chip. Since thermal expansion of the adhesive materials can be accommodated by the base film, memory product packaged using the lead-flame with the single-sided adhesive tape is shown to have much improved reliability. Author allied this invention to the Korea Patent Office for a patent (4-2000-00097-9).

• Transactions of the Korean Society of Mechanical Engineers A
• /
• v.30 no.8 s.251
• /
• pp.985-992
• /
• 2006

Many methods for reliability analysis have been studied and one of them, a moment method, has the advantage that it doesn't require sensitivities of performance functions. The moment method for reliability analysis requires the first four moments of a performance function and then Pearson system is used for the probability of failure where the accuracy of the probability of failure greatly depends on that of the first four moments. But it is generally impossible to assess them analytically for multidimensional functions, and numerical integration is mainly used to estimate the moment. However, numerical integration requires many function evaluations and in case of involving finite element analyses, the calculation of the first fo 따 moments is very time-consuming. To solve the problem, this research proposes a new method of approximating the first four moments based on kriging metamodel. The proposed method substitutes the kriging metamodel for the performance function and can also evaluate the accuracy of the calculated moments adjusting the approximation range. Numerical examples show the proposed method can approximate the moments accurately with the less function evaluations and evaluate the accuracy of the calculated moments.

• Composites Research
• /
• v.23 no.2
• /
• pp.40-47
• /
• 2010

In this paper, the hybrid response surface method(HRSM) is proposed and examined. Hybrid response surface method calculate a approximate model repeatedly based on MPP coordinates. To verify the performance, probability of failure, MPP(Most Probable failure Point) and reliability index are calculated for nonlinear function and composite laminated plate by using reliability analysis method and compared with results by using typical response surface method(RSM). Probability of failure is calculated under the assumption of the nonlinear limit state equation and given failure criterion. The results of proposed method shows performance improvement in estimating the probability of failure.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.8 no.3
• /
• pp.466-471
• /
• 2007

Electrical fires form over 30 percent of fires, but the study on the reliability of electrical fire statistics is not performed. Electrical roe occupancy was very high due to investigating and classifying fires, which is not directly continuous with electrical cause, as electrical fire because insufficiency of cause classification method or system, and the problems of the reliability of electrical fire statistics were presented. So, the reliability of electrical fire statistics must be guaranteed by improvement of the existing cause classification method of electrical fire. This paper analyzed the problems of electrical rue statistics by the existing cause classification method of electrical fire and presented the new method to classify causes of electrical fire.

• Journal of Communications and Networks
• /
• v.17 no.4
• /
• pp.339-345
• /
• 2015

In this paper, we present an iterative reliability-based modified majority-logic decoding algorithm for two classes of structured low-density parity-check codes. Different from the conventional modified one-step majority-logic decoding algorithms, we design a turbo-like iterative strategy to recover the performance degradation caused by the simply flipping operation. The main computational loads of the presented algorithm include only binary logic and integer operations, resulting in low decoding complexity. Furthermore, by introducing the iterative set, a very small proportion (less than 6%) of variable nodes are involved in the reliability updating process, which can further reduce the computational complexity. Simulation results show that, combined with the factor correction technique and a well-designed non-uniform quantization scheme, the presented algorithm can achieve a significant performance improvement and a fast decoding speed, even with very small quantization levels (3-4 bits resolution). The presented algorithm provides a candidate for trade-offs between performance and complexity.

• Journal of the Korean Society for Aeronautical & Space Sciences
• /
• v.31 no.3
• /
• pp.95-100
• /
• 2003

Electronic equipment used in satellites are demanding extremely high reliability, so they should be designed to have immunity for some critical faults by using redundancy component. Generally, Communication satellites are assigned to meet the 15 years mission lifetime, of the analysis about faults must be performed to electronic equipments of satellite. This paper is a summary of the fault tolerance design research of command processor, the improvement of reliability and trade-off study of fault tolerance design result. The reliability prediction value of the satellite component used in this research was taken from Koreasat 3 and Kompsat 1. It is important to perform many trade-off studies for fault tolerance design, especially to choose the most proper fault tolerance method for the specified fault scenario.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.24 no.8
• /
• pp.1-7
• /
• 2010

The reliability of a power system has close relationship with the maintenance of the distribution systems. This paper presents the method of the maintenance planning of the distribution systems by minimizing the interruption cost. The interruption cost for the equipment failures is formulated using time varying failure rate and minimized by optimization of the object function. The proposed method provides the priority list for the investment of the maintenance subject to the limited investment budget by the economic analysis. In order to test the proposed method, the modified distribution system of a rural area is introduced for the testing system. Test results show that the proposed method is good enough by evaluating the improvement of the reliability of the power system.