• Transactions of the Korean Society of Mechanical Engineers A
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• v.30 no.5 s.248
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• pp.568-575
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• 2006

The present paper provides plastic limit load solutions of axial and circumferential through-wall cracked pipes based on detailed three-dimensional (3-D) finite element (FE) limit analysis using elastic-perfectly-plastic behavior. As a loading condition, axial tension, global bending moment, internal pressure, combined tension and bending and combined internal pressure and bending are considered for circumferential through-wall cracked pipes, while only internal pressure is considered for axial through-wall cracked pipes. Especially, more emphasis is given for through-wall cracked pipes subject to combined loading. Comparisons with existing solutions show a large discrepancy in short through-wall crack (both axial and circumferential) for internal pressure. In the case of combined loading, the FE limit analyses results show thickness effect on limit load solutions. Furthermore, the plastic limit load solution for circumferential through-wall cracked pipes under bending is applied to derive plastic $\eta\;and\;{\gamma}$-factor of testing circumferential through-wall cracked pipes to estimate fracture toughness. Being based on detailed 3-D FE limit analysis, the present solutions are believed to be meaningful fur structural integrity assessment of through-wall cracked pipes.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.367-367
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• 2019

최근 기후변화로 인해 국지성 호우 및 태풍의 빈도가 빈발하고 및 규모가 커지고 있으며 그로 인한 홍수피해규모는 증가하고 있다. 본 논문에서는 도시 지역의 호우로 인한 침수유발 강우량을 산정하는 기법의 정확도를 산정하는데 목적이 있으며 이를 위해 ROC(Receiver Operation Characteristic Curve) 분석을 이용하였다. 본 논문에서는 분포형 홍수해석 모형인 S-RAT 모형과 2차원 침수해석 모형 FLO-2D을 커플링하여 호우로 인한 침수해석을 실시하였으며 강우시나리오는 설계 강우 200mm의 강우를 10% 간격으로 증가시켜 강우량 대비 침수심 자료를 모의하였다. 모의한 침수심 자료를 이용하여 유역 격자를 $1km{\times}1km$ 별 강우량-침수심 관계곡선식을 제시하였으며 개발된 곡선식을 이용하여 특정 침수심(20cm)을 유발시키는 강우량(한계강우량)을 산정하였다. 정확도 산정은 ROC(Receiver Operation Characteristic Curve) 분석 방법을 이용하여 침수 유무의 적중률에 따른 민감도와 특이도를 이용하여 AUC(Area Under the Curve)의 점수로 정확도를 판단하였다. 본 논문에서는 본 논문에서 제시한 한계강우량의 정확도를 판단하기 위하여 2011년 7월의 사당역 일대 침수사례를 이용하였다. 실제 침수정보가 없어 실제 호우사상과 실제 하수관망을 고려할 수 있는 SWMM 모형을 이용하여 침수분석을 실시하였다. 분석 결과 평균 ROC는 약 0.7로 나타났으며 5 단계의 구분에서 Fair 단계로 적정 수준의 정확도를 확보한 것으로 나타났다.

• Korean Journal of Remote Sensing
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• v.27 no.5
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• pp.507-520
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• 2011

Conventional radar altimeter system measured directly the distance between the satellite and the ocean surface and frequently used by aircraft for approach and landing. The radar altimeter is good at flat surface like sea whereas it is difficult to determine precise three dimensional ground coordinates because the ground surface, unlike ocean, is very indented. To overcome this drawback of the radar altimeter, we have developed and validated the interferometric radar altimeter signal processing which is combined with new synthetic aperture and interferometric signal processing algorithm to extract precise three-dimensional ground coordinates. The proposed algorithm can accurately measure the three dimensional ground coordinates using three antennas. In a set of 70 simulations, the averages of errors in x, y and z directions were approximately -0.40 m, -0.02 m and 4.22 m, respectively and the RMSEs were about 3.40 m, 0.30 m and 6.20 m, respectively. The overall results represent that the proposed algorithm is effective for accurate three dimensional ground positioning.

• Journal of the Korea Society of Computer and Information
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• v.12 no.5
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• pp.83-92
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• 2007

In this paper, we present a design and implementation of three dimensional pointing device using Inertial Navigation System(INS) that acquires coordinates and location information without environmental dependancy. The INS measures coordinates based on the data from gyroscope and accelerometer and corrects the measured data from accelerometer using Kalman-Filter. In order to implement the idea of three dimensional pointing device, we choose a three dimensional Space-recognition mouse and use RFIC wireless communication to send a measured data to receiver for printing out the coordinate on display equipment. Based on INS and Kalman-Filter theoretical knowledge, we design and implement a three dimensional pointing device and verified the usability as an input device that can capture a human's move. also, we describe the applicability of this device in ubiquitous computing environment.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.13 no.12
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• pp.2693-2700
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• 2009

This paper proposes an effective compression method to utilize the 3D integral image with large amount of data obtained by a lens array in various applications. The conventional compression methods for still images exhibit low performance in terms of coding efficiency and visual quality, since they cannot remove the correlation between elemental images. In the moving picture compression methods, 1D scanning techniques that produce a sequence of elemental images are not enough to remove the directional correlation between elemental images. The proposed method effectively sequences the elemental images from an integral image by the 2D referencing technique and compresses them using the multi-frame referencing of H.264/AVC. The proposed 2D referencing technique selects the optimal reference image according to vertical, horizontal, and diagonal correlation between elemental images. Experimental results show that compression with the sequence of elemental images presents better coding efficiency than that of still image compression. Moreover, the proposed 2D referencing technique is superior to the 1D scanning methods in terms of the objective performance and visual quality.

• Journal of Korea Society of Industrial Information Systems
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• v.25 no.5
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• pp.1-11
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• 2020

Image-based virtual try-on (VTON) is becoming popular for online apparel shopping, mainly because of not requiring 3D information for try-on clothes and target humans. However, existing 2D algorithms, even when utilizing advanced non-rigid deformation algorithms, cannot handle large spatial transformations for complex target human poses. In this study, we propose a 3D clothing reconstruction method using a 3D human body model. The resulting 3D models of try-on clothes can be more easily deformed when applied to rest posed standard human models. Then, the poses and shapes of 3D clothing models can be transferred to the target human models estimated from 2D images. Finally, the deformed clothing models can be rendered and blended with target human representations. Experimental results with the VITON dataset used in the previous works show that the shapes of reconstructed clothing are significantly more natural, compared to the 2D image-based deformation results when human poses and shapes are estimated accurately.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.23 no.2
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• pp.129-136
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• 2005

The usage of the land is enlarged with above-surface space and sub-surface space as well as surface, as the concern about the land use is increased because there are many factors like the recent development of the science technique, Rapid increase of the population, Rapid city's diffusion, industrialization. According to the cubicalness of the land usage such as these, We have the limit to register the right-objects in space like various buildings and facilities by present registration method of 2D cadastre registration because of 2D registration object. Thus, it is necessary for plan to register an ownership, other privilege relations and the physical objects like various buildings and facilities established on both surface and space. There are two steps in this study. First step is the necessity of 3D cadastre registration and object analysis of cadastre registration, second step is 3D cadastre division and its visualization. Finally, this study will present the realizable model for a 3D cadastre registration.

• Korean Association of Arts Management
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• no.51
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• pp.167-190
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• 2019

Copyright law has functioned to certify the authorship and artistic identity of an artist as well as to remunerate the artist's labor in monetary terms. However, the legal stability of copyright law may be questioned and even challenged because it shares the ground with unfixed notions of the concept of art. This study is an attempt to find theoretical argument where such instability of copyright law stems from, by looking into the theories of Aesthetics and history of arts. The first argument builds up on the ambiguity of discriminating between the Aesthetic concept of expression and idea. The second argument illuminates how new conventions of creating art work and emerging ideals of making art prevents to accommodate copyright law in the fields of art. New art forms such as conceptual art and place specific art are such examples. Increasing role of public arts projects also questions the conventional adoptions of copyright law. Arts management is closely related with this phenomena since their job is to administer the complex situation of introducing artists to the knowledge of copyright law.

• Journal of the Korean GEO-environmental Society
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• v.17 no.8
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• pp.39-44
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• 2016

Ground deformation around construction site in urban area where typically adjacent structures are located needs to be strictly controlled. Accordingly, it is very important to precisely monitor the ground deformation. Settlement beacon is typically employed to measure the ground deformation, but meanwhile the rapid development in electronic technology enables 3D image scanner to become available for measuring the ground deformation profile in usual construction sites. With respect to the profile measurement, the 3D scanner has an advantage, whereas its accuracy is somewhat limited because it does not measure the displacement directly. In this paper, we developed a conditional merging technique to combine the ground displacement measured from settlement beacon and the profile measured by the 3D scanner. Synthetic ground deformation profile was generated to validate the proposed technique. It is found that the ground deformation measurement error can be reduced significantly via the conditional merging technique.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.31 no.4
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• pp.199-206
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• 2018

In this study, numerical analysis is applied to a two - dimensional model for verifying the general finite element program, Abaqus' s extended finite element method(XFEM). The cohesive element model used in the existing research has a limitation in simulating the actual crack because of the disadvantage that the crack path should be predicted and the element should be inserted. For this reason, the extended finite element method(XFEM), which predicts the path of cracks based on the directionality and specificity of stress, is emerging as a new solution in crack analysis. The validity of the XFEM application was confirmed by comparing the cohesive element analysis with the XFEM analysis by applying the crack path to the self - evident two - dimensional model. Numerical analysis confirms stress distribution and stress specificity immediately before crack initiation and compares it with actual crack initiation path. Based on this study, it is expected that cracks can be simulated by performing actual crack propagation analysis of complex models.