• Structural Engineering and Mechanics
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• 제11권1호
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• pp.17-34
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• 2001

An improved method has been developed for the computation of the section forces and stiffness in nonlinear finite element analysis of RC plane frames. The need for a new approach arises because the conventional technique may have a questionable level of efficiency if a large number of layers is specified and a questionable level of accuracy if a smaller number is used. The proposed technique is based on automatically dividing the section into zones of similar state of stress and tangent modulus and then numerically integrating within each zone to evaluate the sectional stiffness parameters and forces. In the new system, the size, number and location of the layers vary with the state of the strains in the cross section. The proposed method shows a significant improvement in time requirement and accuracy in comparison with the conventional layered approach. The computer program based on the new technique has been used successfully to predict the experimental load-deflection response of a RC frame and good agreement with test and other numerical results have been obtained.

• 산업경영시스템학회지
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• 제27권4호
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• pp.110-116
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• 2004

ABC analysis is the process of dividing inventory items into three classes according to their monetary usage so that managers can focus on items that have the highest monetary usage value, and has been widely used in practice since its development in 1950. However, the original criterion, monetary usage value, can no longer be the only rational criterion. Applying Analytic Hierarchy Process, we develop a new method to classify inventory items by considering such operationally/strategically important criteria as annual dollar usage, lead time, supplier's capacity, defective rate, difficulty of purchasing and unit price. A case study is performed applying the method to the field data from a company which produces electrochemical products.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2014년도 추계학술대회 논문집
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• pp.106-109
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• 2014

In order to obtain dynamic behaviors of complex structures, it demands large amounts computational cost and time to perform the numerical analysis. The model reduction method helps these problems by dividing the full model into primary and unnecessary parts. In this research, we perform the modal analysis using the dynamic substructuring method, which is one of the model reduction methods, in order to obtain the dynamic characteristics of the cylindrical structures efficiently. To select the master degrees of freedom (dofs), we consider the mode shapes of the cylindrical structures. And then, we identify the validity of the dynamic substructuring method by applying the method to the simple cylinder and core support barrel (CSB) which is one of the reactor internals with the cylindrical shape. The results demonstrate that the dynamic characteristics from the dynamic substructuring method are well matched with the original method.

• Archives of Plastic Surgery
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• 제34권5호
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• pp.628-634
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• 2007

Purpose: Subcutaneous mastectomy has been accepted as a standard for the treatment of gynecomastia. Surgical managements including ultrasound-assisted liposuction(UAL) have had limited success and several combined approaches were tried to find the most effective method. We designed a modified subcutaneous mastectomy, which we call "pan-cake method". The purpose of this study is to evaluate the results of our method for the treatment of gynecomastia. Methods: 16 patients from 16 to 31 years of age having gynecomastia were operated using the pan-cake method. 11 patients were in grade I, and 5 patients were in grade II, no patient were in grade III or IV, according to Rod's classification. The pan-cake method started with modified periareolar incision. We executed subcutaneous dissection first and suprafascial dissection next. After dividing the breast into four equal quadrants, we removed breast tissue from each quadrant as necessary. The operation time for the resection was recorded and the weight of removed parenchyme tissues was measured. Results: All the operations were successful. There were no asymmetries, contour deformities, or irregularities. Only 6 cases needed the combined therapy with ultrasound-assisted liposuction(UAL) because of the step deformities. The average operation time was 24.1 minutes and the average weight of removed breast tissue was 98.1g. All the patients were satisfied with the aesthetic results. Conclusion: We concluded that the pan-cake method is an alternative option for the surgical treatment of gynecomastia, giving good aesthetic results and relatively short operation time.

• 대한전자공학회논문지TC
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• 제39권4호
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• pp.201-208
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• 2002

본 논문에서는 3 차원 임의 형태 도체의 지연 산란 응답을 얻기 위한, 새로운 시간영역 전장 적분방정식(Time-Domain Electric Field Integral Equation: TD-EFIE)을 제안한다. 자기 벡터 전위의 시간 미분항은 중앙 차분으로, 전기 스칼라 전위는 시간에 대한 평균을 취한 두 개의 항으로 근사하였다. 이로부터 도체에 의한 산란 지연 응답 해의 산출시, 기존의 방법보다 정확하고 더욱 안정된 해를 얻을 수 있었다. 제안된 방법의 자세한 정식화 과정을 보였으며, 주파수 영역에서의 이산 푸리에 역변환 (Inverse Discrete Fourier Transform: IDFT) 결과치와 제안된 방법에 의한 수치해를 각각 비교하였다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제5권6호
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• pp.1166-1191
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• 2011

This paper presents an adaptive active tracking system with sector based scanning for a single PTZ camera. Dividing sectors on an image reduces the search space to shorten selection time so that the system can cover many targets. Upon the selection of a target, the system estimates the target trajectory to predict the zooming location with a finite amount of time for camera movement. Advanced estimation techniques using probabilistic reason suffer from the unknown object dynamics and the inaccurate estimation compromises the zooming level to prevent tracking failure. The proposed system uses the simple piecewise estimation with a few frames to cope with fast moving objects and/or slow camera movements. The target is tracked in multiple steps and the zooming time for each step is determined by maximizing the zooming level within the expected variation of object velocity and detection. The number of zooming steps is adaptively determined according to target speed. In addition, the iterative estimation of a zooming location with camera movement time compensates for the target prediction error due to the difference between speeds of a target and a camera. The effectiveness of the proposed method is validated by simulations and real time experiments.

• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제8권7호
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• pp.289-302
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• 2019

시계열의 구조 변화란, 전체 시계열 자료를 구성하는 기간에서 관측치들의 분포가 상대적으로 안정적이다가, 특정 시점에서 분포 특성의 급격한 변화를 보이는 것을 의미한다. 비정상(non-stationary) 장기 시계열 안에서도, 단기적인 추세의 변화가 일시적인 것인지, 아니면 구조적으로 변한 것인지를 적시에 판단하는 것은 중요하다. 이는 시계열 추세의 변화를 상시 감지하여, 변화에 맞는 적정한 대응을 할 필요가 있기 때문이다. 본 연구에서는 단위근 검정법을 기반으로 한 검정 결과를 시각화함으로써, 의사결정자가 시계열의 구조 변화를 손쉽게 파악할 수 있는 방안을 제시하였다. 특히 시계열을 분할한 후 검정하는 방법을 통해, 장기 시계열일 때에도 단기 구조 변화를 파악할 수 있도록 하였다.

• 한국건설관리학회논문집
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• 제5권4호
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• pp.130-138
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• 2004

고층건물의 해체공사는 멀지 않은 장래에 급속도로 증가할 것으로 예상되며, 이들의 일반적인 해체방법은 기계식해체공법과 발파해체공법으로 대별할 수 있다. 해체공법의 결정은 해당건물이 가지는 지리적, 환경적 요인에 따라 많은 변동요인들이 있지만 일상적인 경우라면 경제성 판단이 공법선정의 가장 중요한 요인으로 작용한다. 따라서 본 연구에서는 다른 해체공법 선정요인들 보다는 객관적인 비교가 가능한 도심지 고층건물의 해체비용을 기계식공법과 발파공법으로 구분하여 산출하였으며, 이것의 비교 분석을 통하여 발파해체공법의 향후 활성화 시점을 전망하였다.

• 지능정보연구
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• 제16권3호
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• pp.147-161
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• 2010

최근 방송과 통신의 융합으로 TV에 통신이라는 기술이 접목되면서, TV 시청 형태에 많은 변화를 가져왔다. 이러한 형태의 TV 시청 변화는 서비스 선택의 폭을 넓혀주지만 프로그램을 선택을 위해 많은 시간을 투자해야 한다. 이러한 단점을 개선하기 위해서 본 논문에서는 IPTV환경에서 사용자의 다양한 콘텐츠를 제공하는 방송 환경에서 고객의 시청 정보를 바탕으로 고객 사용정보 온톨로지를 구축하고 그에 따라 고객을 k-medoids 방법을 이용해서 클러스터링 한다. 이를 바탕으로 고객이 선호하는 콘텐츠를 추천 하는 방법을 제안하였다. 실험부분에서 본 제안방법의 우수성을 기존의 방법과 비교하여 보여준다.

• 건축역사연구
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• 제10권2호
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• pp.21-34
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• 2001

The purpose of this study is that it is made clear the construction method of Japanese Castle Architecture in Korea as I study the construction method of Suncheon-Japanese Castle(順天倭城) in those days of Jeong-yu Japanese Invasion. Moreover, I intend to analyze the similarity and the difference between Suncheon-Japanese Castle and Korean Castle Architecture by a comparative study. The result of the study is showed that Suncheon-Japanese Castle seemed to be built with the object of a long time stay rather than it was of strategic importance for the national defense. In addition, it was different from other Japanese Castle in Korea because the watch tower(天守閣) of it stood in the middle of stronghold and the watch tower stronghold dividing the round of it while that of it stood the comer of stronghold. The face stone used in important part of watch tower, gate, and so on was mostly a trimed hexangular stone. On the other hand, the face abbuting on the Gulf of kwang-yang was made of naturally wild face stone. The stone cleared traces of Si-hyeol(矢穴) and domestic Castle in Japan was also made of this method after Im-Jin Japanese Invasion. According to the construction method, the wall of castle made use of the Netak(內托) method except the gate, the support stronghold and the watch. The early mountain castle in Korea have this construction method in common.