• 한국신뢰성학회지:신뢰성응용연구
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• 제15권2호
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• pp.90-100
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• 2015

Reliability growth rate (or reliability growth curve slope) have the two cases of trend as a constant or changing one during the reliability growth testing. The changing case is very common situation. The reasons of reliability growth rate changing are that the failures to follow the NHPP (None-Homogeneous Poisson Process), and the solutions implemented during test to break out other problems or not to take out all of the root cause permanently. If the changing were big, the "Goodness of Fit (GOF)" of reliability growth curve to test data would be very low and then reduce the accuracy of assessing result with test data. In this research, we are using Duane model and AMSAA model for assessing test data and projecting the reliability level of complex and repairable system as like construction equipment and vehicle. In case of no changing in reliability growth rate, it is reasonable for reliability engineer to implement the original Duane model (1964) and Crow-AMSAA model (1975) for the assessment and projection activity. However, in case of reliability growth rate changing, it is necessary to find the method to increase the "GOF" of reliability growth curves to test data. To increase GOF of reliability growth curves, it is necessary to find the proper parameter calculation method of interesting reliability growth models that are applicable to the situation of reliability growth rate changing. Since the Duane and AMSAA models have a characteristic to get more strong influence from the initial test (or failure) data than the latest one, the both models have a limitation to contain the latest test data information that is more important and better to assess test data in view of accuracy, especially when the reliability growth rate changing. The main objective of this research is to find the parameter calculation method to reflect the latest test data in the case of reliability growth rate changing. According to my experience in vehicle and construction equipment developments over 18 years, over the 90% in the total development cases are with such changing during the developing test. The objective of this research was to develop the newly assessing method and the process for GOF level increasing in case of reliability growth rate changing that would contribute to achieve more accurate assessing and projecting result. We also developed the new evaluation method for GOF that are applicable to the both models as Duane and AMSAA, so it is possible to compare it between models and check the effectiveness of new parameter calculation methods in any interesting situation. These research results can reduce the decision error for development process and business control with the accurately assessing and projecting result.

• Korean Journal of Mathematics
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• 제27권1호
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• pp.17-51
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• 2019

In the paper we establish some new results depending on the comparative growth properties of composite entire and meromorphic functions using relative $_pL^*$-order, relative $_pL^*$-lower order and differential monomials, differential polynomials generated by one of the factors.

• 분석과 대안
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• 제4권2호
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• pp.39-70
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• 2020

This paper examines the changing roles of ownership in the economic growth by using a panel data set of 30 provinces in China for the period (1999-2010). With the use of absolute and relative presence variables, this study shows that private enterprises have emerged as the engine of economic growth in China in the later period (2005-2010). The growing size and number of private enterprises are positively linked to growth. However, though foreign-invested enterprises have been acclaimed as the main contributors to economic growth in China, they have minimal effect on the economic growth in the later period. State-owned enterprises have a significant and negative effect on the economic growth in the later period. The results can be interpreted that the engine of growth in China has been changed over time from other ownerships to private ownership. Private companies have developed a lot in every respect and started to lead the economy for long-run growth. China initiated its economic growth by adopting foreign capital and it is still the top destination for foreign direct investment among developing countries. However, to sustain the growth over a long period, private sector should be of great importance and perform a key role in the view of catch-up economics.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2005년도 추계학술대회 논문집 전력기술부문
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• pp.151-155
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• 2005

An electricity consumption is closely related to the economic growth structure. The change of economic growth structure affects the pattern of electricity consumption widely and severely. This paper gives that the primary changing factors of electricity growth are economic growth, change of industry structure(the change of electricity consumption ratio in case of residential sector), and the effect of electricity saying. It gives a model to analyze the influence of GDP to the change of electricity consumption patterns by sector through the period of pre and post 1998(IMF, financial crisis) to observe the contribution of each factor to the growth of electricity demand. It is anticipated that this study shows the feasible scheme of economic structure to become the developed country.

• 한국신뢰성학회지:신뢰성응용연구
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• 제14권2호
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• pp.129-136
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• 2014

Reliability test is focusing to detect the unexpected reliability failure and solve them for the high quality of products. The test data should be used to assess and project the current level of interesting product reliability and so it is very important to have the accurately assessing methodology with test data. There are two type of trend for test data as constant and changing one during testing and this paper shows the difference in the assessing results of these two cases. There is less information how to define the existence of reliability growth rate changing and calculate the parameters of the reliability growth models to make an accurate assessment with such condition, so i established the process and mathematical model to calculate the parameters at such condition to make reliability growth curve with high Goodness of Fit. I validated the new method with the data made from Monte Carlo Simulation and case from Demko (1993). Even the assessed result with the new methodology may be different with the case by case because of very diversity in test condition and testing product quality, but the process and method founded in this research can be applied to any case using Duane and AMSAA model for their test data assessment. I also present the evaluation method to see the effectiveness with new one which is a conventional knowledge and not popular to use, so it is possible to compare the results with the newly presented and conventional method for better business decision.

• 한국신뢰성학회지:신뢰성응용연구
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• 제16권4호
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• pp.305-312
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• 2016

Purpose: The purpose of this study is to provide a sensitivity analysis of system reliability for recognizing effectiveness of changing of BD mode failures using reliability growth projection model based on NHPP. Methods: Crow extended reliability projection model (CERPM) is used to analyze the changing of two factors 1) the number of BD mode failures, 2) fix effectiveness factor (FEF) values. Results: The system reliability has increased in accordance with the number of BD mode failures and FEF values have increased. Conclusion: It is necessary to design failure modes and FEF values to supervise the reliability.

• 한국인구학
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• 제18권2호
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• pp.23-50
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• 1995

이 글은 한국의 인구변천이 환경변화에 어떻게 영향을 미치고 있는가를 규명하고 있다. 이 관계는 기본적으로 경로모형(path model)의 틀로서 설명되고 있다. 인구증가는 그 자체만으로도 직접적으로 환경을 오염시키는 원인이 되고 있다. 인구증가는 또한 각각 도시화 및 산업화를 유발시킴으로서 환경오염의 간접적인 원인이 되고 있다. 한편, 도시화와 산업화는 서로 상승작용을 통해서 환경오염에 영향을 미치고 있다. 이 글에서는 이와 같은 이론적 틀에 입각하여 한국의 인구성장, 도시화 및 공업화의 추세를 살펴보고 이들 요인들이 환경변화에 어떻게 영향을 미치고 있는가를 분석하고 있다. 또한 환경오염의 변화양태를 대기오염과 수질오염 그리고 폐기물의 변화추세로써 살펴보고 있다. 마지막으로 환경변화의 결과가 한국적인 상황에서 어떻게 나타나고 있는가가 논의되고 있다.

• 한국인구학
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• 제8권2호
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• pp.11-29
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• 1985

이 글은 한국의 인구변천이 환경변화에 어떻게 영향을 미치고 있는가를 규명하고 있다. 이 관계는 기본적으로 경로모형(path model)의 틀로서 설명되고 있다. 인구증가는 그 자체만으로도 직접적으로 환경을 오염시키는 원인이 되고 있다. 인구증가는 또한 각각 도시화 및 산업화를 유발시킴으로서 환경오염의 간접적인 원인이 되고 있다. 한편, 도시화와 산업화는 서로 상승작용을 통해서 환경오염에 영향을 미치고 있다. 이 글에서는 이와 같은 이론적 틀에 입각하여 한국의 인구성장, 도시화 및 공업화의 추세를 살펴보고 이들 요인들이 환경변화에 어떻게 영향을 미치고 있는가를 분석하고 있다. 또한 환경오염의 변화양태를 대기오염과 수질오염 그리고 폐기물의 변화추세로써 살펴보고 있다. 마지막으로 환경변화의 결과가 한국적인 상황에서 어떻게 나타나고 있는가가 논의되고 있다.

• 한국수학교육학회지시리즈B:순수및응용수학
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• 제25권3호
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• pp.193-201
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• 2018

In this paper, we discuss central index oriented and slowly changing function based some growth properties of composite entire functions.

• 한국전기전자재료학회논문지
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• 제26권6호
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• pp.446-450
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• 2013

Growth mechanism of GS-MBE(Gas source-Molecular Beam Epitaxy) has been investigated. We observed that the growth rate of GaN films is changing from 520 nm/h to 440 nm/h by the variation of V/III ratio under nitrogen-rich growth condition. It was explained that the amount of hydrogen on the growth front varies by the ammonia flow, and gallium hydrides are generated on the surface by a reaction of hydrogen and gallium, resultantly the amount of gallium supplying is changing along with the $NH_3$ flow. Reflection high energy electron diffraction (RHEED) observation was used to confirm the N-rich condition. The crystal quality of GaN was estimated by photoluminescence (PL) and X-ray diffraction (XRD).