• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2020.11a
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• pp.43-45
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• 2020

궁극의 3D 디스플레이 기술이라고 할 수 있는 홀로그램 기술로 실물을 보는 것과 같은 3차원 영상이 가능해 지고 있다. 그러나 디지털 홀로그램 영상의 데이터양은 HD나 UHD 영상의 수십에서 수천 배에 달해 원본 화질의 열화를 최소화 하면서 데이터양을 줄이기 위한 압축 부호화 기술이 매우 중요하다. 본 논문에서는 위상 홀로그램 동영상에 대해 최신 영상 압축 표준인 HEVC(High Efficiency Video Coding)와 VVC(Versatile Video Coding)로 압축한 후 홀로그램 영역과 수치 복원 영역에서 압축 성능을 비교하며, 다양한 실험영상에 대한 HEVC 압축 결과에 대해 객관적 압축성능 분석 및 주관적 성능 분석을 진행한다.

• Proceedings of the Korea Water Resources Association Conference
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• 2015.05a
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• pp.337-337
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• 2015

홍수 저감, 생태계 복원, 위락 등 다양한 목적의 충족을 위해 강변에 저류지, 즉 다목적 유수지(detention basin)를 조성하는 사례가 나타나고 있다. 하천에서 홍수의 발생으로 수위가 어떤 기준보다 높아지면, 흐름의 일부를 돌려 저류지로 보냄으로써 본류의 부담을 덜 수 있다. 이때, 흐름의 분기를 위해 설치되는 하천구조물 중 하나가 측면 위어(side weir) 또는 횡월류 위어(side discharge/overflow weir)이다. 하천의 계획과 설계에서 위어가 적용될 때, 위어에 대한 수위-유량 관계, 즉 그 형식과 제원에 적합한 유량계수(discharge coefficient)의 결정이 관건이 된다. 일반적인 위어와 달리 흐름 양상이 복잡한 측면 위어의 경우, 이론과 실제의 괴리가 아직까지 해소되지 않아 실물 또는 3차원 수치 모형을 이용한 시험으로 수위-유량 관계를 수립할 필요가 있다. 이렇게 결정된 수위-유량 관계는 1차원 또는 수심적분 2차원 모형의 내부 또는 외부 경계로 사용되며, 본류의 수위 증감에 따른 측면 위어의 횡월류량을 통해 저류지의 홍수 조절 능력을 평가할 수 있다. 이 연구에서는, 측면 위어의 수위-유량 관계가 알려지지 않더라도, 저류지에 의한 홍수 조절 효과를 평가할 수 있는 2차원 수치모의에 대해 검토하였다. 수치해법으로서 2차원 천수방정식에 대해 유한체적법을 적용하고, 흐름률(flux)의 정확한 계산을 위해 근사 Riemann 해법을 도입하였다. 먼저, 측면 위어가 없는 실험 조건에 대해 수로 내 한 측선에서 측정된 수위와 유량을 모의 결과와 비교하여 모형을 검증하였다. 이때, 경계조건으로 상류 끝에 측정 유량을, 하류 끝에 측정 수위를 부여하였으며, Manning의 조도계수를 0.014로 설정하였다. 또한, 측면 위어가 설치된 수로에 대해 계산 영역을 340개의 삼각형 격자로 분할하고 측면 위어가 없는 경우와 동일한 조건을 두어 모의하였다. 측면 위어의 하류에 위치한 측선에서 측정치에 대한 평균 제곱근(root mean square) 오차가 수위에 대해 1.9 mm, 유량에 대해 $2.2{\ell}/s$로서 그림과 같이 모의 결과는 실험의 그것과 잘 일치하였다. 이로써, 측면 위어에 대한 수위-유량 관계의 수립을 위한 실물 모형 시험 없이 수심적분 2차원 수치모의를 통해 저류지의 홍수 조절 효과를 평가할 수 있음이 확인되었다.

• Journal of the Korea Fashion and Costume Design Association
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• v.25 no.4
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• pp.107-122
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• 2023

This study analyzed the style, dimensions, fabric patterns, colors, and fabrics of a traditional Chinese women's dress from the Zhou Dynasty, and reconstructed it in the form of a virtual garment using 3D CLO. Based on ancient flat image data and three-dimensional portrait data, who wore them, how they were worn, and how they were coordinated was analyzed. In order to analyze the size and pattern of the straight Ju Chines dress, data from the excavation report and the tomb owner's anthropometric measurements were combined to infer the wearing condition and organize the sculptural features. Dimensional analysis was carried out using a well-preserved small-scale woven cotton cloth as a restoration model, and the horizontal and vertical dimensions were reasonably estimated using the shape proportioning method. The analysis of the colors and patterns of the fabrics was based on the colors and patterns of the fabrics excavated from Masan Tomb No. 1 during the Eastern Zhou, Qin, and Han periods. Finally, a virtual model was created using data from the excavation report and the age and height information of the owner of the excavated robe, and the pose and size of the virtual model were determined using 3D CLO. Based on the previous research data, the garment was virtually sewn and simulated. The shape, pressure, and strain of the garment in different postures was also compared. Through the research direction of pattern and 3D restoration, this research maximizes the restoration of Chinese traditional women's dress and presents it in a more intuitive, comprehensive, and vivid way.

• Korean Journal of Heritage: History & Science
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• v.56 no.2
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• pp.246-262
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• 2023

This study analyzed policy implementation factors focusing on how Donuimun, a demolished cultural heritage, was digitally restored and the policy implementation process of Donuimun Gate restoration. Through this, the characteristics of the implementation process of the digital Donuimun Gate restoration policy promoted by public-private multilateral collaboration were examined and implications were sought for how institutions with different interests solved problems and collaborated in the implementation process. The research method was focused on policy implementation factors including policy executive factors, policy content factors, policy resource factors, and policy environment factors, and the process was analyzed for each detailed component. Along with literature analysis, in-depth interviews were conducted with participants in policy implementation. As a result of the study, first, it was found in the policy executive factor that the quick decision-making leadership of the policy manager and the flexible attitude of the person in charge of the government agency had a positive effect on preventing conflicts between different interest groups. Second, in terms of policy content, establishing a common goal that everyone can accept and moving forward consistently gave trust and created synergy. Third, in the policy implementation resource factor, the importance of the budget was emphasized. Finally, as an environmental factor for policy implementation, the opening of 5G mobile communication for the first time along with the emergence of the Fourth Industrial Revolution at the time of policy implementation acted as a timely factor. The digital Donuimun Gate was the first case of restoring a lost cultural heritage with AR and VR, and received attention and support from the mass media and the public. This also shows that digital restoration can be a model case that can be a solution without conflicts with local residents where cultural heritages are located or conflicts between stakeholders in the preservation and restoration of real objects.

• Journal of the Korean Society of Costume
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• v.57 no.7
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• pp.153-161
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• 2007

In 2004, Mal-gun(抹裙) was excavated from a plastered tomb in Seok-nam-dong, In-cheon. This tomb is assumed to be from an upper-class woman. The excavated Mal-gun was used to fill in the empty spaces in coffin, and it was seriously damaged and foxed dark. The Mal-gun is made with thin, loose Sook-cho(숙초), and the width of the fabric is 70cm. Both sides of the crotches are overlapped in front, and the back is opened. The waist straps are detached, leaving a little part to show the width of the straps. The hems of the Mal-gun are sewed straight, without any pleats, except some spaces for the feet to go through. This study compared the Mal-gun of Joseon Dynasty from the documentary records and picture records with the excavated Mal-gun from Seok-nam-dong, In-chceon. Also, actual Mal-gun was manufactured according to the excavated Mal-gun to study the process of manufacturing and the formation. As a result, the excavated Mal-gun has the same form of that shown in Ak-hak-gwae-bum, a documentary record from the early period of Joseon Dynasty.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.32 no.2A
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• pp.65-73
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• 2012

In this study, we tested structural performance of Half-Decked PSC girder which was developed for applying to long span bridge. We operated 4 point bending test with 60 m span full scale girder designed as simple bridge with hinge-roller boundary condition. Actuators were set on the both sides of girder, 5.5 m away from the center, and 4 stages of cyclic loading was applied at rate of 1 kN/sec. Through stages 1 to 4, loading and unloading 1,000 kN, 1,200 kN, 1,500 kN, and 2,000 kN were repeated and displacement, strain of concrete and steel, crack of girder were checked. From these results, the strength of girder was assessed and resilience and ductility were observed after removing the load. Since initial flexural crack occurred in the vicinity of 1,400 kN, non-linearity of load-displacement curve appeared and definite residual strain was measured at that point. The test result showed that initial cracking load was over twice the DB-24 load which means the developed girder had sufficient strength. To verify the experimental results, we numerically analyze the test and confirmed that the data were similar with results from the test above. Half-Decked PSC type of 60 m-girder developed in this study showed its adequate structural capacity through static loading test, which proved that possibility of applying the girder to actual bridges practically.

• Journal of Conservation Science
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• v.31 no.1
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• pp.75-86
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• 2015

A scale Armor is usually excavated in a scattered form weakened by corrosion after its burial. Therefore, they should be brought into the indoor in a safe environment for the on-site conservation treatment as it was excavated. They should be placed on a stable support with a reinforced base in the indoor treatment. In this process, the bottom surface which can not be observed after the conservation treatment is placed for a record by actual survey and photography. But this method had a limit on figuring out the whole aspects of the artifact. For compensating the defect, duplication of the artifact was considered as an alternative method for the previous two methods in the case of conservation of the scale Armor from Jinyoung 2-Area, Gimhae. Neck guard was excavated in a distorted form by the earth pressure, and was hard to recognize the original shape. However, whole real material of its original form was secured through the combination of each duplicated lamellae. Throughout the application of the duplication technique in the process of conservation of scale Armor and neck guard, it could secure the real material of the bottom surface and elevate the understanding of the artifact. Moreover, a constitution of the armor could be identified more effectively.

• Korean Journal of Heritage: History & Science
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• v.56 no.1
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• pp.80-97
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• 2023

By taking wallpaper specimens from Gyeongbokgung Palace, Changdeokgung Palace, and Chilgung Palace preserved from the late Joseon Dynasty to the present, we planned in this study to determine the types and characteristics of the paper used as wallpaper in the Joseon royal family. First, we confirmed the features of paper hanging in the palaces with old literature on the wallpaper used by the royal family based on archival research. Second, we conducted a field survey targeting the royal palaces whose construction period was relatively clear, and analyzed the first layer of wallpaper directly attached to the wall structure after sampling the specimens. Therefore, we confirmed that the main raw material was hanji, which was used as a wallpaper by the royal family, and grasped the types of substances(dyes and pigments) used to produce a blue color in spaces that must have formality by analyzing the blue-colored paper. Based on the results confirmed through the analysis, we checked documents and the existing wallpaper by comparing the old literature related to wallpaper records of the Joseon Dynasty palaces. We also built a database for the restoration of cultural properties when conserving the wallpaper in the royal palaces. We examined the changes in wallpaper types by century and the content according to the place of use by extracting wallpaper-related contents recorded in 36 cases of Uigwe from the 17th to 20th centuries. As a result, it was found that the names used for document paper and wallpaper were not different, thus document paper and wallpaper were used without distinction during the Joseon Dynasty. And though there are differences in the types of wallpaper depending on the period, it was confirmed that the foundation of wallpaper continued until the late Joseon Dynasty, with Baekji(white hanji), Hubaekji(thick white paper), jeojuji(common hanji used to write documents), chojuji(hanji used as a draft for writing documents) and Gakjang(a wide and thick hanji used as a pad). As a result of fiber identification by the morphological characteristics of fibers and the normal color reaction(KS M ISO 9184-4: Graph "C" staining test) for the first layer of paper directly attached to the palace wall, the main materials of hanji used by the royal family were confirmed and the raw materials used to make hanii in buildings of palaces based on the construction period were determined. Also, as a result of analyzing the coloring materials of the blue decorative paper with an optical microscope, ultraviolet-visible spectroscopic analysis(UV-Vis), and X-ray diffraction analysis(XRD), we determined that the type of blue decorative paper dyes and pigments used in the palaces must have formality and identified that the raw materials used to produce the blue color were natural indigo, lazurite and cobalt blue.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.5
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• pp.27-33
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• 2010

In this study, a monotonic loading test to estimate structural capacity of 12 meter long full scale precast pre-stressed concrete beam specimen was performed with a 2,000 kN dynamic actuator. A couple of embedded steel plate was installed at the ends of the beam and specimens were connected to steel girder frame with high tension bolts. Nominal compressive strength of pre-stressed concrete beam and slab were 50 MPa and 24 MPa respectively. Two HD25 tensile steel reinforcements were welded on vertical plate of embedded steel plate. Pre-stressed concrete beam specimen was loaded by displacement control method with a certain loading pattern which was repeated loading and unloading with 10mm increment displacement. About 88.34%, 86.97% and 66.83% of displacement restoration ratios were evaluated at elastic, inelastic and plastic behavior region of specimen respectively.

• Journal of Cadastre & Land InformatiX
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• v.47 no.1
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• pp.179-190
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• 2017

A terrestrial LiDAR survey was conducted and unmanned aerial vehicle(UAV) images were taken for target cultural properties to present the utilization measures of terrestrial LiDAR and UAV in three-dimensional modeling of cultural properties for the identification of the status and restoration of cultural properties. Then the accuracy of the point clouds generated through this process was compared, an overlap analysis of the 3D model was conducted, and a convergence model was created. According to the results, the modeling with terrestrial LiDAR is more appropriate for precise survey because 3D modeling for the detection of displacement and deformation of cultural properties requires an accuracy of mm units. And UAV model has limitation as the impossibility of detailed expression of parts with sharp unevenness such as cracks of bricks. However, it is found that the UAV model has a wide range of modeling and has the advantage of modeling of real cultural properties. Finally, the convergence model created in this study using the advantages of the terrestrial LiDAR model and the UAV model could be efficiently utilized for the basic data development of cultural properties.