• Korean Journal of Fisheries and Aquatic Sciences
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• v.22 no.5
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• pp.317-331
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• 1989

Chaenogobius laevis inhabit brackish waters. Adult male protects egg mass laid under the stones. The egg with small oil globule varied from 3.40 to 4.04 mm in diameter. When water temperature is $22.0\~23.0^{\circ}C$, larvae hatched about 113 hours after fertilization. The newly hatched larvae reared for 33 days grow up to 12.10 mm in total length and developed to the jevenile. When larvae length attained about 8.0 mm, jaw bones were more rapidly ossified than vertebrae and cranium.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.18 no.10
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• pp.42-47
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• 2017

In this study,we conducted an injection molding analysis of metal powder materials for the development of flanges, which are necessary adapters for optical communication. The metal powder injection molding process is a technique for producing an injection molded article having a complicated shape by mixing ceramic or stainless powder and binders. It is used to produce products which require complex processing technology or for which the productivity is low. The purpose of this study is to minimize the manufacturing processing of products which are manufactured through existing mechanical processing procedures. For the injection molding analysis, we mixed stainless STS316 metal powder with binders at a ratio of 6 to 4 to make molding materials consisting of granular pellets. Then, three-dimensional modeling and meshing were carried out to obtain the optimal injection molding analysis conditions(molding temperature, melting temperature, injection time, injection temperature, injection pressure, packing time and cooling time). As a result of the analysis, it was discovered that the inlet became available 13.29 seconds after the first injection. Also, as the flowing and packing in the melt through the sprue, runner and gate were stable, it is expected that good molds can be manufactured.

• Journal of Astronomy and Space Sciences
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• v.22 no.4
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• pp.451-462
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• 2005

Optimal Trajectory Correction Maneuver (TCM) design algorithm has been developed using the B-plane targeting method for future Korean Mars missions. For every-mission phase, trajectory informations can also be obtained using this developed algorithms which are essential to design optimal TCM strategy. The information were computed under minimum requiring perturbations to design Mars missions. Spacecraft can not be reached at designed aim point because of unexpected trajectory errors, caused by many perturbations and errors due to operating impulsive maneuvers during the cruising phase of missions. To maintain spacecraft's appropriate trajectory and deliver it to the designed aim point, B-plane targeting techniques are needed. A software NPSOL is used to solve this optimization problem, with the performance index of minimizing total amount of TCM's magnitude. And also executing time of maneuvers on be controlled for the user defined maneuver number $(1\~5)$ of TCMs. The constraints, the Mars arrival B-plane boundary conditions, are formulated for the problem. Results of this work show the ability to design and analyze overall Mars missions, from the Earth launch phase to Mars arrival phase including capture orbit status for future Korean Mars missions

• Journal of Conservation Science
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• v.31 no.2
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• pp.131-145
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• 2015

Cultural assets restoration is being considered highly as a practical way to extend the lifespan of damaged cultural assets and re-highlight their value. However, restoration process has been mostly dependent on the manual work involving the experience and skill of a person performing restoration, thereby requiring much time and effort. In recent, it became possible to apply a method allowing restoration to be performed more accurately and easily according to the material characteristics and shape of cultural assets. Namely, it is to use a method of printing out the 3D shape data computed in computer as real object by using 3D printer for the restoration that has been performed manually. The missing part of a cultural asset is computed into computer data first and is printed out by using 3D printer to undergo a simple shaping process. The result of 3D printer application showed that repetitive output and shape and figure revision of digital data were possible, and it was possible to improve the degree of completedness of restoration through test output using various types of restoration materials using various materials. For the purpose of verifying the possibility of applying 3D printer to restore missing part of earthenware, two pieces of modern reproductions, namely, the Seven Treasure Incense Burner and Earthenware with Wagon Wheel Decoration, were artificially damaged. The restoration result showed that compared to manual work, it showed better effectiveness in curtailing work time and reproducing accurate shape. On the other hand, secondary manual work was slightly needed for detailed binding and to vividly express surface texture.

• Proceedings of the Korea Water Resources Association Conference
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• 2011.05a
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• pp.128-128
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• 2011

본 연구에서는 자동유량측정시설에 의하여 실시간으로 생산되는 자동유량측정 자료의 정상성 여부를 판단하는데 중요한 적정 측정 신뢰구간을 실시간으로 예측할 수 있는 기술을 개발하였다. 전세계적으로, 현대적인 유량측정이 시작된 이래 연속유량 산정을 위한 방법은 수위-유량관계곡선을 이용하는 방법 외에 실무적으로 활용 가능한 방법은 거의 전무한 실정이다. 수위-유량관계곡선을 이용하는 방법은 연속수위를 계측하여 이에 해당하는 연속유량을 산정하는 방법으로 수위와 유량간에 일정한 관계를 가지는 정상적인 흐름을 보이는 자연하천의 경우에 정확도가 매우 높다. 그러나 감조나 구조물 등에 의해 유량이 조절되는 경우에 유량산정의 정확도는 현저히 떨어지게 된다. 따라서 수위에서 유량을 환산하는 방법이 아닌 유량을 직접 연속으로 측정하는 방법이 꾸준히 연구되어 왔고, 이 중 가장 대표적인 방법이 자동유량측정 방법이다. 그러나 자동유량측정 방법은 유량을 연속으로 측정할 수 있다는 장점에 반해 측정된 유량의 정확도를 높이기가 매우 어렵다는 단점도 가지고 있다. 계측 자체의 기술적 한계는 주로 계측기기적인 문제로 이는 전자기, 통신 기술 등 첨단 기술의 발전과 함께 다양한 현장 시험을 통해 폭넓은 개선이 이루어지고 있다. 그러나 아직 기술적 완성도가 완전하지 못한 현실에서, 현재 설치되어 있는 자동유량측정 유량자료의 신뢰도를 높이기 위해서는 각각의 계측 시점에서 자료가 정상적으로 산정되고 있는지에 대한 검정이 필요하고, 이는 자동유량측정 자료의 정확도 확보에 매우 중요한 관건으로 작용할 수밖에 없다. 이러한 배경에서 본 연구에서는 조석성분과 유출성분을 분리하여 예측하는 방법을 새롭게 개발 적용하였다. 자료는 자료의 시간해상도 증감에 따른 실제 예측의 정확도 증감을 고려하여 가장 적절하다고 판단되는 시자료를 사용하였으며, 자료간 상관을 분석하여 주 입력 자료로 팔당댐 방류량, 한강대교 지점 수위, 전류 수위를 이용하였다. 모형의 예측 능력을 극대화하기 위하여 조석 영향을 받는 자료의 경우는 웨이블릿 변환(wavelet transform)을 이용하여 순수 유출성분과 조위성분을 분리하여 별도로 적용하였다. 그리고 예측을 위한 모형은 실시간 자료기반 모형으로 그 안정성이 인정된 서포트벡터머신(support vector machine)을 이용하였다. 이러한 과정을 통해 한강대교 지점의 순수 유출성분과 조위성분의 유량을 각각 예측한 후 두 결과를 합성하여 최종 한강 대교 지점의 유량을 산정하였다. 조석성분을 분리하여 한강대교 지점의 유량을 예측한 결과 대부분의 예측치가 95% 예측구간에 포함되었다. 그리고 조석성분을 분리하지 않은 모형과 조석성분을 분리한 모형의 예측 능력을 비교한 결과, 조석성분을 분리한 모형이 예측이 정확도가 높았다. RMSE의 경우 분리하지 않은 모형대비 23%의 예측오차가 감소하였고, NSC의 경우 0.92에서 0.95로 예측의 정확도가 증가하였다.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.20 no.4
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• pp.56-68
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• 2019

Safety-conscious design on site is required for site constructions because of the introduction of the design for safety, but it still leaves much to be desired. This study compared the site where the design was applied and the site where it was not applied. The applied case examined the underground wall construction during frame construction, which corresponds to the skeleton of the building construction. The underground wall construction is quite risky due to the exposure to exterior environments and involvement of various stages, such as scaffolding, formwork, reinforcing work, and concrete casting work. Therefore, the risk factors for each stage were identified and a risk assessment was carried out to select an alternative method to reduce the risk. The risk factors of the selected alternative construction method were also identified and a risk assessment was conducted. The risk assessment weight was calculated by comparing the site where the construction method was applied and the site where it was not, explaining the necessity of the design for safety in reducing the risk. In addition, an actual case where an alternative construction method was used was studied to highlight the necessity for a design for safety.

• The Journal of the Korea Contents Association
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• v.19 no.8
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• pp.370-388
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• 2019

From 2010, new keyword of so-called devising theatre in the Korean performing arts scene has emerged. The backdrop is the antipathy to the hierarchical creative environment, the search for a language that can reflect increasingly complex societies, and the influx of new performances from abroad. Of course, devising theatre can be realized in a wide variety of forms in the actual field, so it cannot be defined as one methodology. But commonly all these various forms of the attempts aim to create a democratic relationship among participants, and process-centered breakthrough in the hierarchy of creative materials such as texts, sounds. light and human body. In 2017, Creative VaQi seeks to find new keyword called 'Reality of Division in Korean Peninsula' and to develop it into performance languages experimenting inter-disciplinary devising methodology. The company conducted a walking trip alongside the division line(300km) and tried to achieve the landscape and traces of division. After the walking, they created a specific form and performing contents called "Walking Holiday" out of their experiences. In this thesis, I will analyze the whole process of the devising "Walking Holiday" and examine what kind of result it led to. Furthermore, I, as the director of "Walking Holiday" will continue to discuss new possibilities and limitations of devising theatre methods that the company tries and aim at this time.

• Korean Journal of Breeding Science
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• v.50 no.4
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• pp.364-377
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• 2018

Hexaploid wheat (common wheat/bread wheat) is one of the most important cereal crops in the world and a model for research of an allopolyploid plant with a large, highly repetitive genome. In the heritability of agronomic traits, variation in gene presence/absence plays an important role. However, there have been relatively few studies on the variation in gene presence/absence in crop species, including common wheat. Recently, a reference genome sequence of common wheat has been fully annotated and published. In addition, advanced next-generation sequencing (NGS) technology provides high quality genome sequences with continually decreasing NGS prices, thereby dawning full-scale wheat functional genomic studies in other crops as well as common wheat, in spite of their large and complex genomes. In this review, we provide information about the available tools and methodologies for wheat functional genomics research supported by NGS technology. The use of the NGS and functional genomics technology is expected to be a powerful strategy to select elite lines for a number of germplasms.

• Journal of Korea Water Resources Association
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• v.54 no.3
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• pp.181-190
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• 2021

In this study, a large-scale levee breach experiment from lateral overflow was conducted to verify the effect of the new reinforcement method applied to the levee's surface. The new method could prevent levee failure and minimize damage caused by overflow in rivers. The levee was designed at the height of 2.5 m, a length of 12 m, and a slope of 1:2. A new material mixed with biopolymer powder, water, weathered granite, and loess in an appropriate ratio was sprayed on the levee body's surface at a thickness of about 5 cm, and vegetation recruitment was also monitored. At the Andong River Experiment Center, a flow (4 ㎥/s) was introduced from the upstream of the A3 channel to induce the lateral overflow. The change of lateral overflow was measured using an acoustic doppler current profiler in the upstream and downstream. Additionally, cameras and drones were used to analyze the process of the levee breach. Also, a new method using 3D point cloud for calculating the surface loss rate of the levee over time was suggested to evaluate the performance of the levee reinforcement method. It was compared to existing method based on image analysis and the result was reasonable. The proposed 3D point cloud methodology could be a solution for evaluating the performance of levee reinforcement methods.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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• v.39 no.3
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• pp.187-201
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• 2021

Recently, the demand for a 3D urban spatial information infrastructure for storing, operating, and analyzing a large number of digital data produced in cities is increasing. CityGML is a 3D spatial information data standard of OGC (Open Geospatial Consortium), which has strengths in the exchange and attribute expression of city data. Cases of constructing 3D urban spatial data in CityGML format has emerged on several cities such as Singapore and New York. However, the current ecosystem for the creation and editing of CityGML data is limited in constructing CityGML data on a large scale because of lack of completeness compared to commercial programs used to construct 3D data such as sketchup or 3d max. Therefore, in this study, a method of constructing CityGML data is proposed using commercial 3D mesh data and 2D polygons that are rapidly and automatically produced through aerial LiDAR (Light Detection and Ranging) or RGB (Red Green Blue) cameras. During the data construction process, the original 3D mesh data was geometrically transformed so that each object could be expressed in various CityGML LoD (Levels of Detail), and attribute information extracted from the 2D spatial information data was used as a supplement to increase the utilization as spatial information. The 3D city features produced in this study are CityGML building, bridge, cityFurniture, road, and tunnel. Data conversion for each feature and property construction method were presented, and visualization and validation were conducted.