• Magazine of the Korea Concrete Institute
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• v.11 no.1
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• pp.77-87
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• 1999

The conventional design of prestressed concrete box girder bridges has been based on the linear elastic analyses using simplified geometric models. To overcome the restriction involved in the simplifications, a macro element for the rational analysis of prestressed concrete box girder bridges with variable cross sections is incorporated in the present analysis. Through the adoption of nonlinear material models, the behaviour of prestressed box bridges up to ultimate loading stage can be examined. The time dependent material models included in the present macro element code enable to predict the long term behaviour of prestressed concrete box girder bridges. The proposed macro element code with the nonlinear material models and time dependent routines can be efficiently used for the realistic analysis of prestressed concrete box girder bridges with arbitrary shapes.

• Proceedings of the Korea Water Resources Association Conference
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• 2006.05a
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• pp.1479-1482
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• 2006

본 연구는 우리나라 강수자료 중 90년 이상의 자료를 보유한 지점(서울, 인천, 목포, 부산)에 대해서 변화도 분석과 Singular Spectrum Analysis(SSA)를 사용하여 자료의 주성분 및 주기성을 분석하였다. 각 자료의 변화도 분석결과 1907에서 2004년까지 98년간의 장기변화 중 선형추세에 의한 강우변화량은 23-11mm/mon 증가한다. 선형추세에 의한 년 강우변화량은 276-132mm/yr 이며 증분의 약 65%가 8월 증가량으로 과거 30년 강우분포는 7월에만 피크를 가지나 최근 30년의 강우분포는 7월과 8월에 비슷한 피크를 가지는 변화를 보일 뿐 아니라 지역에 따라 상이한 분포 양상을 보였다. 강우의 선형적 증가와 함께 변화폭도 증가하며 서울, 인천지역이 목포, 부산지역보다 큰 증가 양상을 보였다. 월 변화패턴과 선형추세 등 확정적 변화를 제거한 anomaly는 장기 변동과 각 달에 대해 다른 변동 폭을 가지는 noise의 합의 형태로 나타난다. Moving ave rage를 이용한 장기변동양상은 특정 주기를 가지지 않을 뿐만 아니라 변동 폭도 noise의 변동 폭에 비하여 미소하다. SSA결과 첫 번째 주성분이 전체변화의 1.7%이며 30번째 성분은 전체변화의 약 1% 정도로 장주기의 변화를 보였으나 전체자료에 비해 각 요소들이 설명하는 비중이 상당히 낮았다.

• Management & Information Systems Review
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• v.30 no.2
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• pp.113-131
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• 2011

Today, researches on logistics service quality or supply chain management are highlighted due to intensification of competition and diversification of needs for customer service. This study have done a comparative analysis on supply chain partnership members' perception difference about importance of logistics service quality factors. It measured perception about logistics service quality which suppliers, carriers, and buyers regard as important and then conducted t-test in order to compare perception difference. It was found that quality factors of logistic service which suppliers, carriers, and buyers in supply chain partnership perceive as important were different. And disagreements among members were found in most items when market orientation and long term orientation was low while there was no difference among most members when market orientation and long term orientation was high.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.16 no.2
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• pp.13-22
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• 2017

The present study proposes a new methodology for predicting the demand for truck rest areas beside national highways. Previous demand forecasting methods were reviewed first in order to complement them with additional items. The results of the study are as follows. In the demand forecasting process, the primary task is to divide parking demands of trucks into short-term parking and long-term parking. Since short-term and long-term parking vary in utilization, congestion, and turnover rate, different influence factors should be considered according to parking time. Furthermore, the demand characteristics of rest and convenience facilities need to be reflected as well, because they in turn affect the demand for truck rest areas. In sum, the demand forecasting process for destination-type truck rest areas on national highways requires more attention than that for truck rest areas on expressways, and possible influences of various factors should be examined in this process.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.9
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• pp.1185-1191
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• 2010

Aged aircraft have several cracks as a results of long-term service, and these cracks affect the safety and decrease the rate of operation of the aircraft. To solve these problems, crack propagation analysis should be performed to determine the service life at fatigue critical location(FCL). It is, however, almost impossible to obtain the stress spectrum, which is crucial for crack propagation analysis of the FCLs of wing structure of aged aircraft. In this study, to analyze the fatigue crack propagation behavior at the FCL of an aged aircraft, first finite element analysis is performed for a 3D geometry model of the aircraft wing structure, which is obtained using CATIA based on the paper drawings. Then, the transfer function and stress-spectrum of the FCL are derived using the load factor data and the FEA results. Finally, the crack propagation rates of the FCL are evaluated using the commercial software, NASGRO 6.0.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.35 no.2
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• pp.119-129
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• 2022

It is essential to control the lateral displacement and differential axial shortening of the vertical elements in high-rise buildings. The differential axial shortening can cause challenges in the serviceability and safety of non-structural and structural elements, respectively. Hence, in this study, the differential axial shortening of the vertical elements and effects of long term behaviors of concrete are analyzed in 120-story high-rise buildings via the construction sequence analysis. Consequently, the axial shortening of the vertical elements is classified into elastic, creep, and shrinkage shortening, and dominant factors to the maximum axial shortening are analyzed. In addition, the serviceability of the non -structural elements is checked with a differential axial shortening at 30 years after completion of construction, and member forces at design and construction stages in girders and outrigger walls are compared.

• Journal of Digital Convergence
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• v.11 no.10
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• pp.669-677
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• 2013

Traditional Chinese Boardgame as the Chinese national traditional culture has experienced thousands of years. But the rules of the game did not change. Since today, the game mainly concentrated in the old age. In recent years also born some Chinese chess improvement scheme, they changed chessboard shape, the user number, chess rules and so on, but did not pop up. This paper is the development of the Chinese chess, improvement plan to do a survey, and with the game interesting elements as the center is analyzed.

• Journal of the Korea Concrete Institute
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• v.17 no.6 s.90
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• pp.1025-1032
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• 2005

This paper presents experimental and analytical studies on long-term behavior of square CFT columns with diaphragm. In order to investigate the effect of the diaphragm on the long~term behavior, experiments for six specimens with two diaphragms and three different column length, and three-dimensional finite element analysis for each specimen have been performed. The finite element models considering the interface behavior between the steel tube and the inner concrete were verified from comparison of the test results with the analysis results. From the test and the analysis results, the following conclusions were obtained. The confinement effect created by the diaphragm does not depends on column length and influences only a part of the whole column that is from the end to the depth which is the same to the width of the column. The shortening of the column with diaphragm which covers more than a half of the cross sectional area of the inner concrete is the same as that of the column under a load applied on the steel tube and the entire section of the inner concrete.

• Journal of Advanced Navigation Technology
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• v.16 no.3
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• pp.553-561
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• 2012

The study has focused on relationship benefits provided for customers in terms of relationship marketing and empirically analyzed the influence of components of relationship benefits in air service. Those components are, for example, social, psychological, economic and special treatment benefits on long-term orientation of relationship. Also, ultimately, this study aims to suggest marketing strategies and relevant implications for airlines. In conclusion, psychological and special treatment benefits were found to have influence on long-term orientation of relationship.

• The Korean Journal of Financial Management
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• v.9 no.1
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• pp.35-55
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• 1992

Black과 Scholes가 옵션가격모형(價格模型)을 개발한 후 그 모형에서의 가정들을 완화시킴으로써 옵션모형들이 발전되어 왔다. Black-Scholes의 옵션가격모형(價格模型)의 문제점중의 하나는 주가의 분산이 만기일까지 일정(一定)하다는 가정이다. 본 연구에서는 장기옵션이 Scorer 이용하여 주가분산(株價分散)의 중요성을 고찰하였다. 즉 Cox, Ingersoll과 Ross의 일반균형이론(一般均衡理論)에 근거한 random variance 옵션모형을 도출하였고 이것을 Black-Scholes 옵션모형과 비교하였다. 장기유럽식 옵션에 대하여 주가변동성(株價變動性)의 위험(危險)프레미엄이 중요한 요소이고 위험(危險)프레미엄을 고려한 random variance 옵션모형이 위험(危險)을 고려치 않는 random variance옵션모형(模型)보다 예측력이 높게 나타났다.