• Journal of the Korean Institute of Gas
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• v.8 no.3 s.24
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• pp.8-15
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• 2004

This paper presents von Mises stress, deformation, and rotating distortion moment characteristics of inner tank bottom plate as a function of a cryogenic temperature difference along the radial distance from the center area to the corner one. The calculated results show that the filling level of LNG at the beginning of the cool-down process is very important for the design safety analysis of the inner tank. Obviously the thermal loading by a temperature difference between the LNG vapor gas of $-80^{\circ}C$ and a LNG temperature of $-162^{\circ}C$ affects to the thermal related characteristics of the bottom plates and annular one. From the computed results, the temperature difference by a vapor gas and liquid of LNG may lead to the thermal instability of the bottom plate. This phenomenon may cause the system failure of an inner tank.

• Journal of the Korean Institute of Gas
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• v.11 no.4
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• pp.85-90
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• 2007

This paper presents the finite element analysis on the strength safety of a full containment LNG storage tank system with damping safety structures. For the FEM analysis of the inner tank, the combined loads in which are related to a hydrostatic pressure, a cryogenic temperature load, BOG pressure, LNG weight, and a sinking force at the comer of the inner tank have been applied to the inner tank structure. The FEM computed results show that the conventional inner tank is safe for the given combined loads, but the damping safety structure such as compressive springs may be more useful structures to increase the safety of the tank system. The increased stiffness and the appropriate position of the springs are very important design parameters for increasing the damping strength safety of the tank system.

• Journal of the Korean Society for Railway
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• v.20 no.5
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• pp.637-648
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• 2017

In this paper, the effects of initial built-in deformation and temperature deformation on the stress distribution of discontinuous precast concrete track slab under train load were examined. According to the results, when train load is put on a precast concrete slab with initial built-in deformation and deformation due to temperature gradient, the maximum tensile stresses develop at the upper side of slab in the slab center, edge center and corner of shear pocket; the stress distribution is different from that of the case under train load only. Therefore, to accurately predict the actual weak points and failure modes, one should calculate the stress under train load considering the initial built-in and temperature deformation of the slab.

• Journal of the Korea Convergence Society
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• v.11 no.5
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• pp.175-182
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• 2020

The calculation of the optimal trajectory of the stepped top-down robot was made using a genetic algorithm and a computational torque controller. First, the total energy efficiency was minimized using the Red-Cold Generic Algorithm (RCGA) consisting of reproductive, cross, and mutation. The reproducibility condition related to the position assembly of the start and end of the stride and the joints, angles, and angular velocities are linear constraints. Next, the unequal constraint accompanies the condition for preventing the collision of the swing leg at the corner with the outer surface of the stairs, the condition of the knee joint for preventing kinematic peculiarity, and the condition of no moment in safety in the traveling direction. Finally, the angular trajectory of each joint is defined by fourth-order polynomial whose coefficient is to approximate chromosomes. This is to approximate walking. In this study, the energy efficiency of the optimal trajectory was analyzed by computer simulation through a biped robot with seven degrees of freedom composed of seven links.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.17 no.2
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• pp.93-98
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• 2024

This paper presents the method to extract the ultrawide-band (UWB) signal and proposes the simple impulse radar system for sensing real-based target within close-range area. The proposed impulse radar system consists of impulse generator, ultrawide-band antennas, function generator, and digital oscilloscope. It is verified by experiment that a differentiated Gaussian pulse is generated with 200ps of pulse width and corresponding spectrum from 0.3 to 4.7 GHz once a sinusoidal wave with 10MHz is excited. The Gaussian doublet is received by identical antennas and it is shown that the UWB pule width of 328ps and its spectrum is from 0.9 to 4.4 GHz. It is confirmed that the UWB pulse is extracted when the real-based targets such as circular target with 4cm radius and corner reflector are placed at the close-range area.

• Journal of KIISE:Computer Systems and Theory
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• v.31 no.3_4
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• pp.224-238
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• 2004

Multi-modality image registration is a widely used image processing technique to obtain composite information from two different kinds of image sources. This study proposes an image registration method based on moment information and surface distance, which improves the previous surface-based registration method. The proposed method ensures stable registration results with low registration error without being subject to the initial position and direction of the object. In the preprocessing step, the surface points of the object are extracted, and then moment information is computed based on the surface points. Moment information is matched prior to fine registration based on the surface distance, in order to ensure stable registration results even when the initial positions and directions of the objects are very different. Moreover, surface comer sampling algorithm has been used in extracting representative surface points of the image to overcome the limits of the existed random sampling or systematic sampling methods. The proposed method has been applied to brain MRI(Magnetic Resonance Imaging) and PET(Positron Emission Tomography), and its accuracy and stability were verified through registration error ratio and visual inspection of the 2D/3D registration result images.

• Journal of the Korean Recycled Construction Resources Institute
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• v.9 no.4
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• pp.537-544
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• 2021

In order to describe the fill-up stages of a near-surface disposal facility vault, a mock-up test is performed, and its behavior during the fil l -up stages is investigated. On an in-site concrete foundation with a l ength of 6600mm, a width of 6600mm and a thickness of 400mm, a reinforced concrete disposal vaul t is manufactured with 4 precast (PC) corner wal l s and 8 PC side wal l s. 36 wasted drums are pl aced on the 1st fl oor in 6 by 6, and then the empty space is fil l ed with grout fil l er. These processes are repeated up to the 5th floor, and the verticality and the joint gaps are measured for each fill-up stage. The verticality is measured using a level at 6 positions on each side wall (3 positions on the left and right sides, respectivel y), i.e. a total of 24 positions on the 4 side wal l s. The joint gaps are measured at 9 positions on each side wal l (3 positions on the left, center and right sides, respectively), I.e. a total 36 positions on the 4 side walls. To measure the joint gaps, crack tips are installed on the left and right sides of every joint gap, and vernier calipers are used. The measured verticality obtained through the mock-up test was found to be ±0.1° based on the initial stage (ST0), and the result of the joint gap was up to 0.38mm. This appears to have a negligible effect on the structure.

• Journal of Broadcast Engineering
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• v.21 no.1
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• pp.36-42
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• 2016

Recently, many 3D contents have been produced through the multiview camera system. In this system, since a difference of the viewpoint between color and depth cameras is inevitable, the camera parameter plays the important role to adjust the viewpoint as a preprocessing step. The conventional camera calibration method is inconvenient to users since we need to choose pattern features manually after capturing a planar chessboard with various poses. Therefore, we propose a semi-auto camera calibration method using a circular sampling and an homography estimation. Firstly, The proposed method extracts the candidates of the pattern features from the images by FAST corner detector. Next, we reduce the amount of the candidates by the circular sampling and obtain the complete point cloud by the homography estimation. Lastly, we compute the accurate position having the sub-pixel accuracy of the pattern features by the approximation of the hyper parabola surface. We investigated which factor affects the result of the pattern feature detection at each step. Compared to the conventional method, we found the proposed method released the inconvenience of the manual operation but maintained the accuracy of the camera parameters.

• Journal of Korean Society of Steel Construction
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• v.29 no.3
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• pp.249-260
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• 2017

In order to investigate the structural performance of a novel prefabricated-SRC column using bolt-connected steel angles(PSRC column), eccentric axial loading tests were performed for six PSRC column specimens and two conventional SRC column specimens. The test parameters were the spacing and sectional configurations of lateral reinforcement, and eccentricity ratio of axial load. The test results showed that, due to high axial-stiffness of the angles located at the corners of the cross section, the compressive load-carrying capacity and deformation capacity of the PSRC specimens were greater than those of the SRC specimens in the large eccentricity ratio of axial load. Closely spaced lateral steel plates and Z-shaped lateral steel plates improved lateral confinement, which increased the load-carrying capacity of the PSRC specimens. The combined flexural and axial load-carrying capacity of the specimens by tests and nonlinear numerical analysis were greater than the predictions by current design codes. The numerical analysis agreed well with the test results including the initial stiffness, peak strength, and post-peak strength degradation.

• Proceedings of the ESK Conference
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• 1997.10a
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• pp.142-151
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• 1997

본 연구는 주부들의 주활동공간인 부엌가구와 공간의 설계에 있어사용하기 편리하며 가사활동에 따 른 피로를 경감시키고 요통과 같은 주부직업병을 예방할 수 있는 부엌가구와 공간의 개발에 그 목적을 두었다. 연구는 먼저 수도권의 32평형 규모의 아파트150가구를 대상으로 설문조사를 실시하였으며, 만 24시간동안의 실제 가사활동을 Video로 촬영하여 동작분석을 실시하였다. 그 결과 주부들은 수납의 용 이성과 공간의 크기, 작업대의 높이 등을 가장 많은 개선사항으로 지적하였으며, 절반이상의 주부들이 앉은 자세에서 작업이 이루어졌으면 좋겠다고 응답하였다. 또한 동작분석 결과 작업의 70%이상이 개수 대를 중심으로 조리대와 가열대 주변의 한정된 공간에서정적으로 선 자세에서이루어지는 것으로 파악 되었다. 이러한 선 자세에서의 작업에 따른 피로도를 감소시키기 위하여 입좌식 의자를 도입하였으며, 개수대를 씽크대의 'ㄱ'자 코너에 위치하여 주방활동시의 이동거리를 단축하고자 하였다. 피로도의 경감 을 측정하기 위하여 입좌식 의자를 도입한 개선된 씽크대와 기존의 입식씽크대에서 가사활동시 요구되는 주부들의 에너지 대사량을 비교하기 위하여 심장박동수와 산소호흡량을 측정하였다. 실험결과에 따르면 주방에 입좌식의자를 도입한 경우가 가사활동에 요구되는 에너지 소모량이 심장박동수와 산소호흡량의 기준에서 각각 평균적으로 30%와 57.5% 이상이 감소하는 것으로 파악되어 이러한 부엌가구의 도입으로 주부들의 가사활동에따른 피로도가 절반 가까이 감소될 수 있음을 니타내었다. 또한 부엌가구의 재배치 에따른 가사활동시 이동거리가 평균적으로5.5%이상이 감소하는 것으로 나타났다. 본 연구결과를 주방설 계에 적용할 경우 가사활동의 효율성과 편리성이 향샹됨은 물론 가사활동에따른 피로도를 경감 시키고 요통 등의 주부직업병을 예방할 수 있을 것으로 기대된다.1일 1회씩 4회 투여한 군에서도 암수에 상관없이 전 농도 군에서 염색체이상을 나타내지 않아 유전독성을 나타내지 않음을 관찰하였다. 특히 vitamin C와 E의 병용투여는 상승적으로 적용하여 간세포손상을 더욱 억제시킴을 알 수 있었다.mance and on TFP(Total Factor Productivity) growth which is a pure measure of firm performance. To utilize the advantage of panel data, FEM(Fixed Effect Model) and REM(Random Effect Model) were used. The empirical result shows that the entropy index as a measurement of inter-business relatedness is not significant but technological relatedness index is significant. OLS estimates on pooled data were considerably different from FEM or REM estimates on panel data. By introducing interaction effect among the three variables for business portfolio properties, we obtained three findings. First, only VI (Vertical integration) has a significant positive correlation with ROS. Second, when using TFP growth as an dependent variable, both TR(Technological Relatedness) and f[ are signif