Robot manipulators are highly nonlinear system with multi-inputs multi-outputs, and various control methods for the robot manipulators have been developed to acquire good trajectory tracking performance and improve the system stability lately. The computed torque controller has nonlinear feedforward control elements and so it is very effective to control robot manipulators. If the control gains of the computed torque controller is adjusted according the payload, then more precise control performance is attained. This paper extends the conventional computed torque controller in the joint space to the Cartesian space, and optimize the control gains for some specified payloads in both joint and Cartesian spaces using genetic algorithms. Also a neural network is employed to have proper control gains for arbitrary payloads using generalization properties of the neural network. Computer simulation results show that the proposed control system for robot manipulators has excellent performance in various conditions.

백두산에서는 밀레니엄 대분화 이후로도 수차례의 화산활동이 계속되어 마그마 거동 감시 연구의 필요성이 지속적으로 제기되고 있다. 마그마방의 깊이 및 규모를 파악하기 위해서는 다양한 지구물리학적 접근이 필요하며, 본 연구에서는 전기비저항 탐사의 적용성을 검토하고자 한다. 국경으로 인해 공간적 제한이 있는 백두산에서 심부에 위치한 마그마를 탐사하기 위해서는 측선의 길이가 수십 킬로미터 이상이 되는 대규모 전기탐사가 이루어져야 하며, 이를 위해 서는 분산계측 시스템의 도입과 이에 최적화된 탐사 설계가 필수적으로 요구된다. 따라서 자체 개발된 분산계측 시스템을 활용하는 탐사설계안을 제시하고 전산실험을 통해 적용 가능성을 분석하였다. 단일 측선과 비동일선상 송신원 배열을 사용한 탐사설계안을 이용하여 다수의 측선 설치가 필요한 일반적인 3차원 탐사에 준하는 역산 해석 결과를 얻을 수 있음을 확인하였으며, 이 탐사설계안이 백두산 심부 물리탐사에 유용하게 적용될 수 있을 것으로 기대된다.

This study examines the restoration project of Sokkuram, and introduces its preliminary plans by the architect Pai Ki Hyung. The restoration project started in 1958 with an inquiry committee of the restoration project, and was completed in 1964. Despite having undergone extensive repair work under Japanese supervision from 1913 and 1923, the repair work caused water leakages inside Sokkuram, and regular cleaning work that began in 1933 caused a lot of damage to the sculpture. In result of the surveys, the top priority of this project was to protect the sculptures inside Sokkuram by improving the environment of the cave. At that time, the architect Mr. Pai participated as a head of the fourth field surveyors to plan the restoration project and to design the preliminary plans. He proposed the installation of a double dome structure to prevent further water leakages on the concrete addition that was built up around the grotto by the Japanese. However, in 1961, the Cultural Heritage Committee of Korea examined the plans of Mr. Pai and immediately rejected them. The factors of the rejection were the omitting of entrance design, system of new double dome structure that presses the existing structure, and these changes that had to be made outside of the drainage plans. The repair work of Sokkuram began in 1961, and the main construction was building double dome structure and entrance installation. In this we realize that Mr. Pai’s double dome structure plans were very important key concept of this project. This study attempts to demonstrate the double dome installations that Mr. Pai initially proposed, which ultimately remains as emblematic factors of Sokkuram’s legacy.

스페이스 하우스는 강재 프레임에 FRP와 우레탄 폼을 결합한 합성패널로 구성된 단위모듈방식의 프리캐스트화한 구조물이다. 이 연구는 모듈러 건축물의 한 종류인 스페이스 하우스의 설계와 구조적 거동을 예측하였다. 스페이스 하우스의 하중 저항은 대부분 강재 프레임에서 발생하기 때문에 직육면체 형태의 강재 프레임 구조물에 수직보강재를 보강하여 제작하였다. 또한, 구조물의 안전성을 확보할 수 있도록 구조 검토와 유한요소해석을 통해 구조물의 사용성과 안전성을 확인하였다.

PURPOSES : In Korea, asphalt overlay has been used as a typical alternative rehabilitation method for deteriorated pavements. However, asphalt overlay has problems due to poor bonding of the asphalt overlay and the old concrete. Recently, concrete overlays, which have advantages such as long-term durability and high structural capacity to carry heavy traffic, have been considered for rehabilitation construction. However, concrete overlays have limitations such as difficulty in opening to traffic and pavement noise. Recently, an appropriate fine-size exposed aggregate concrete pavement technique was reported to solve these problems. Therefore, this study aims to suggest an optimum mixture design of fine-size exposed aggregate concrete overlay (EACO) that can ensure low noise and early strength. METHODS : The optimum mixture design of fine-size EACO is determined to ensure adequate structural performance for early traffic opening and good functional performances such as low noise. Therefore, the optimum mixture proportion is determined based on the optimum design of aggregate content to produce a low-noise pavement texture by controlling the exposed aggregate number (EAN) and mean texture depth (MTD). RESULTS : The water-cement ratio and unit cement ratio were used to determine the mixture designs to achieve workability and adequate strength for early traffic opening. The texture was determined by selecting the maximum size of coarse aggregate smaller than 10 mm with an S/a ratio of less than 30% for low noise. With these mixture proportions, the EAN and MTD were 50±5 / 25cm2 and 1.0±0.2 mm. Respectively, which meet the criteria for EACO. CONCLUSIONS: In this study, an optimum mixture design of EACO for early traffic opening and low noise is suggested by using earlyhigh strength cement, and the pavement texture is implemented considering EAN and MTD. In addition, a pavement surface texture criterion is suggested for the quality control of EACO.

본 연구의 목적은 In-DEBS (In-situ Demonstration of Engineered Barrier System) 시험장치에 대한 설계안을 도출하고, 현장실증용 공학적방벽재의 생산을 위한 최적 제작조건을 도출하는 것이다. 이와 관련하여 그간 한국원자력연구원에서 수행한 실증실험 수행경험과 문헌분석 그리고 선진핵주기 고준위폐기물처분시스템(AKRS)을 근거로 시험장치를 설계하였다. 또한 처분용기와 벤토나이트 완충재는 시험제작을 통해 최적의 제작조건을 도출하였고, 예비 성능평가를 통해 제작된 공학적방벽재의 성능을 검증하였다. In-DEBS 현장시험을 위해서 AKRS의 1/2.3 규모로 설계하였으며, 고른 온도분포의 핵연료 모사를 위하여 설계 전력량 4.2 kW의 알루미늄 재질 몰드히터를 사용하였다. 한편 In-DEBS에 사용될 공학규모 이상의 균질 완충재 블록을 제작하기 위해 플롯팅 다이(floating die) 방식의 프레스 재하 및 냉간등방압프레스(CIP; Cold Isostatic Press) 기법을 국내 최초로 완충재 제작에 적용하였다. 연구결과 AKRS 완충재 블록 제한요건(건조밀도 › 1.6 kg·cm-3)을 충족하기 위해서는 1차로 40 MPa 이상의 플롯팅 다이 프레스 압력을 가하고, 2차로 50 MPa의 CIP 압력이 소요됨을 확인하였다. 또한 완충재 블록 내 센서설치를 위하여 CNC (Computer Numerical Control) 기법을 이용하여 센서위치를 정교하게 성형하였다

In this study, a design procedure for the practical application of the dampers to building structures under earthquake loads was presented by using earthquake response spectrum. Nonlinear time history results using a 10 story building structure installed with damper verified the effectiveness of the proposed procedure by showing that the structural response could be reduced to the target performance level for seismic loads. Since the proposed design procedures are based on response spectrum seismic analysis result of the original structure, the capacity, location and the number of damper and the consequent response reduction effects can be preliminarily determined without performing the nonlinear time history analysis.

In this paper, the shape adjustment algorithm of the spoked wheel cable structures with retractable membrane system is studied. The initial tension of the membrane or cable is necessary to form the structure and its value is determined by the design shape. However, due to internal and external environmental influences, its shape may be different from the initial designed shape. In the case of the cable structures covered in this study, tension adjustment is necessary to maintain the designed shape because it influences the tension of the cable depending on the state of the retractable membrane. Therefore, we proposed an adjustment algorithm of an initial shape based on the force method. The effectiveness and validity of the methodology were examined through the applicable cable structures. The results of the shape adjustment analysis of the symmetric spoked wheel cable model were reliable and accurate results were obtained.