• Geomechanics and Engineering
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• 제13권2호
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• pp.237-254
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• 2017

Estimation of slope stability is a very important task in geotechnical engineering. However, its estimation using conventional and soft computing methods has several drawbacks. Use of conventional limit equilibrium methods for the evaluation of slope stability is very tedious and time consuming, while the use of soft computing approaches like Artificial Neural Networks and Fuzzy Logic are black box approaches. Multiple Regression (MR) analysis provides an alternative to conventional and soft computing methods, for the evaluation of slope stability. MR models provide a simplified equation, which can be used to calculate critical factor of safety of slopes without adopting any iterative procedure, thereby reducing the time and complexity involved in the evaluation of slope stability. In the present study, a multiple regression model has been developed and tested its accuracy in the estimation of slope stability using real field data. Here, two separate multiple regression models have been developed for dry and wet slopes. Further, the accuracy of these developed models have been compared and validated with respect to conventional limit equilibrium methods in terms of Mean Square Error (MSE) & Coefficient of determination ($R^2$). As the developed MR models here are not based on any region specific data and covers wide range of parametric variations, they can be directly applied to any real slopes.

• Nuclear Engineering and Technology
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• 제47권7호
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• pp.895-906
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• 2015

Background: Mitigation of primary water stress corrosion cracking (PWSCC) is a significant issue in the nuclear industry. Advanced nickel-based alloys with lower susceptibility have been adopted, although they do not seem to be entirely immune from PWSCC during normal operation. With regard to structural integrity assessments of the relevant components, an accurate evaluation of crack growth rate (CGR) is important. Methods: For the present study, the extended finite element method was adopted from among diverse meshless methods because of its advantages in arbitrary crack analysis. A user-subroutine based on the strain rate damage model was developed and incorporated into the crack growth evaluation. Results: The proposed method was verified by using the well-known Alloy 600 material with a reference CGR curve. The analyzed CGR curve of the alternative Alloy 690 material was then newly estimated by applying the proven method over a practical range of stress intensity factors. Conclusion: Reliable CGR curves were obtained without complex environmental facilities or a high degree of experimental effort. The proposed method may be used to assess the PWSCC resistance of nuclear components subjected to high residual stresses such as those resulting from dissimilar metal welding parts.

• 대한조선학회지
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• 제4권1호
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• pp.59-65
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• 1967

Since the screw propellers were adopted as ship propulsion devices, the replacement of propeller shaft due to damage was mostly of fatigue failure due to the alternative stresses [1],[2]. To prevent such a failure, hence, it is suggested that careful attention should be paid to account of the alternative stresses on the design stage of the propeller shafts. In connection with this fact the Ship Classification Societies' Rules are regarded simply as guidance for preliminary determination of the shaft diameter. In this paper, limiting the topic to the small and medium-sized motor ships, an evaluation of the Rules formulae to a theoretical based on Soderberg's correlation [5] between the factor of safety and the resultant stresses obtained by application of the maximum shear theory is done. For this purpose eleven (11) ships built recently in Korea were taken as a species(refer to table 2. in text). In the end the following conclusions are made: (1) In general the Rules formulae give considerably larger size of the propeller shaft diameter than that derived from theoretical calculation, that is, about 7% more in AB and BV Rules, and about 20% more in LR and KR-NK Rules. (2) LR Rule gives the largest size of all, and AB Rule is mostly closed value to the theoretical. (3) The formular of the AB Rule is considered to be of the simplest in utilization and of the reasonable.

• 설비공학논문집
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• 제12권10호
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• pp.950-961
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• 2000

The objective of this study is to develop optimal alternative selection model for renewing building equipments system. Cost Breakdown Structure of LCC in HVAC systems are deduced from resonable data and factors. As for Cost Breakdown Structure of LCC in HVAC system, pertinent level, title, CBS number, and block number are determined efficiently. Especially, in addition to current cost factor, it is possible to make Cost Breakdown Structure using present worth method more clear. A model of POWER LCC ver 1.0 used to analyze primary cooling system, heating system, and air conditioning system are POWER LCC ver 1.0_/sub SYSTEM/ : C1+ C2- C3+ C4+ C5+ C6+ C7±C8+ C9- C10/sub -1/+ C10/sub -2/+ C10/sub -3/, and is implemented with consideration of Cost Breakdown Structure and their summation using present-worth method. It is programmed with one of scientific languages, MATLAB 5.3.

• Structural Engineering and Mechanics
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• 제78권2호
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• pp.219-230
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• 2021

International seismic codes stipulate that adjacent buildings should be separated by a specified minimum distance, otherwise the pounding effect should be considered in the design. Recent researches proposed an alternative method (Double Difference Combination Rule) to estimate seismic gap between structures, as this method considers the cross relation of adjacent buildings behavior during earthquakes. Four different criteria were used to calculate the minimum separation distance using this method and results are compared to the international codes for five separation cases. These cases used four case study buildings classified by different heights, lateral load resisting systems and fundamental periods of vibrations to assess the consistency in results for the alternative methods. Non-linear analysis was performed to calculate the inelastic displacements of the four buildings, and the results were used to evaluate the relation between elastic and inelastic displacements due to the ductility of structural elements resisting seismic loads. A verification analysis was conducted to guarantee that the separation distance calculated is sufficient to avoid pounding. Results shows that the use of two out of the four studied methods yields separation distances smaller than that calculated by the code specified equations without under-estimating the minimum separation distance required to avoid pounding.

• 한국환경복원기술학회지
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• 제26권6호
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• pp.221-234
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• 2023

This study was conducted to develop a habitat assessment system for the endangered wildlife II Kirengeshoma koreana Nakai through in-depth interviews with experts based on field surveys and environmental characteristics through spatial data analysis and literature research. Evaluation factors were selected based on the survey results of 31 variables for 23 K. koreana habitats. Afterwards, the importance and evaluation range for each assessment factor were selected. The selection of survey variables, assessment factors, importance of each factor and assessment range was conducted through in-depth interviews with experts at each stage. As a result, the assessment factors and importance were 16% for precipitation of the wettest month, 10% for vegetation zone, 12% for vegetation type, 10% for crown canopy vitality, 14% for tree layer coverage, 13% for drainage grade, 12% for soil depth, and 13% for distance to stream including dry stream. This study provides basic ecological information and a habitat assessment system for K. koreana habitats. Therefore, it can be used as primary data for preparing an endangered wildlife conservation policy, preparing a habitat improvement plan, and selecting an alternative habitat.

• 한국컴퓨터정보학회논문지
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• 제17권10호
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• pp.185-192
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• 2012

콜센터는 고객과의 접촉에 있어 비대면 채널에 의해 커뮤니케이션이 이루어지기 때문에 대면 접촉에 의한 것보다 더 많은 상담사의 능력을 요구한다. 이러한 상담사의 능력개발을 위해 콜센터들은 경력과 직무에 따라 다양한 교육훈련을 실시하고 있으며, 교육훈련의 성과로 상담품질이나 생산성 향상을 실현하고자 한다. 한편, 교육훈련에는 많은 시간과 예산이 투입되기 때문에 교육훈련의 평가를 통해 현업수행에 도움이 얼마나 되고 있는지 그 효과성이 파악되고 관리되어야 할 것이다. 지금까지의 교육훈련의 평가에 대한 연구들을 보면 만족도와 학습정도를 측정하거나 학습이 행동에 전이되는 정도를 측정하는 연구가 주류를 이루어 전체적인 평가모형에 관한 연구가 필요하다. 본 연구에서는 콜센터교육훈련의 효과성을 상담사들의 인식수준에서 Kirkpatrick의 4단계 평가모형을 반영하여 반응, 학습, 행위, 결과에 대한 각 단계별 평가기준 간에 어떠한 영향관계가 있는지 알아보고, 구조방정식 모델을 사용하여 전체적인 모형의 적합도를 살펴보았다, 또한 대안모형으로 반응요인과 행위요인의 직접적인 관계를 고려하여 연구모형과 대안모형의 구조모델 적합도를 비교 분석하였다.

• 한국엔터테인먼트산업학회논문지
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• 제13권4호
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• pp.207-216
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• 2019

이 연구는 축구 동호인들의 축구 관련 미디어 관여 경험과 용품구매의사 및 참여지속의도 간의 관계를 통해 축구 동호회 및 관련 용품업체의 지속가능한 성장에 필요한 기초 자료를 제공하는데 목적이 있다. 이러한 연구 목적을 달성하기 위해 G광역시에 거주하는 축구동호인 327명에 대한 설문조사를 실시하였다. 탐색적 요인분석과 내적 일관적 분석을 통해 자료의 타당도와 신뢰도를 확보한 후 기술통계 및 상관관계 분석 그리고 다중회귀분석을 실시하여 다음과 같은 결론을 도출하였다. 첫째, 축구 관련 미디어 관여 경험 요인에서 기술의 수준이 가장 높았으며 다음으로 도전, 흥미 순으로 나타났다. 둘째, 용품구매의사 요인에서 대안평가 단계의 수준이 가장 높았으며, 다음으로 구매인식, 문제인식 그리고 정보탐색 순으로 나타났다. 셋째, 축구 관련 미디어 관여 경험은 용품구매의사에 영향을 미치는 것으로 나타났다. 특히 기술 요인이 용품 구매의사에 부(-)의 영향을 미치는 것으로 나타났다. 넷째, 축구 관련 미디어 관여 경험은 참여지속의도에 영향을 미치는 것으로 나타났다. 특히 기술 요인이 참여지속의도에 정(+)의 영향을 미치는 것으로 나타났다. 다섯째, 용품구매의사는 축구 동호인들의 참여 지속의도에 영향을 미치는 것으로 나타났다. 문제인식은 부(-)의 영향을 그리고 대안평가는 정(+)의 영향을 미치는 것으로 나타났다. 이 연구에서는 미디어 관여 경험 요인 중 기술이 가장 중요하게 고려되어야 할 것이며, 용품구매의사 결정단계를 보다 선제적으로 대응하여 이해할 필요가 있을 것이다. 따라서 이러한 관여도와 이해도를 높이기 위해서는 SNS를 활용한 상호 커뮤니케이션의 필요성이 강조된다.

• 한국측량학회지
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• 제26권6호
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• pp.591-598
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• 2008

최근 정부에서는 도로의 기하구조 불량으로 인해 사고 발생률이 높은 대상지에 대해 위험도로개선사업을 추진 중에 있다. 비록, 도로의 노선을 선택하는 것이 기본적이고 중요한 과정이지만 노선 선정의 과정은 기술적, 안전적, 환경적인 요소들을 모두 고려해야 한다. 또한, 3차원 지형모델 기술은 대체 노선선정에 대한 설계와 계획에서 중요한 요소로 사용될 수 있다. 수치지도와 노선도의 조합에 의해 생성된 3차원 지형도를 조합한 실험의 경우, 주요 간선 도로 건설현장에서 다차원적인 접근 방법을 제공하기 위해 개발되었다. 3차원 수치표고 모형은 개발계획과 시공계획에 대해 설계 시공 현장에서 실시간 가상 접근을 제공하는 GIS기반으로 다양한 지표 분석을 가능하게 한다. 따라서 본 연구에서는 수치지도에 GPS측량과 토털스테이션(Total Station)측량을 이용하여 취득한 현황 측량 정보를 결합하여 노선 선정에 따른 3차원 공간 정보를 비교 검토하고 토공량 산정시 보다 정확한 양을 산정하여 도로선형개선에 활용할 수 있도록 하고, 주관적인 평가를 통하여 대체 노선에서 노선선정에 대한 합리적인 방법을 제시하고자 한다.

• 복식
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• 제51권2호
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• pp.105-120
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• 2001

The purpose of this study is to identify the relationship of self-efficacy, which is a kind of the self concept about one's own ability, to the decision-making process, which is the key part of consumer behavior. The subjects in this study were 985 male and female undergraduates of a university located in the city of Kyongsan, the north Kyongsang province. The collected data were statistically processed by MANOVA and ANOVA. For post test, Scaffle and $\chi$$^2$-test were employed. The followings are findings of this study : 1. Concerning incentive to buying, the group having the weaker general self-efficacy is stimulated more highly by the incentives of self-display, fashion pursuit and economic utility than the group having the stronger general self-efficacy does. 2. Regarding information sources. the factor of observation is frequently used by the group having the weaker general and social self-efficacies more than the group having the stronger general and social self-efficacies. 3. As to the evaluative criteria of clothes, the group having the stronger general and social self-efficacies put a higher value on functional and economical points than the group having the weaker general and social self-efficacies does. 4. As for the evaluative criteria of store the group having the stronger general self-efficacy lays stress on store atmosphere, store attributes and convenient shopping condition, while the group having the weaker general self-efficacy puts emphasis on brand and fashion. 5. In buying apparels, the group having the stronger general and social self-efficacies makes more planned purchase.