• Journal of Industrial Technology
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• v.29 no.B
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• pp.57-64
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• 2009

This study has analysed actual overbreak, shotcrete rebound and the ratio between the actual quantity of shotcrete to designed shotcrete measured during a NATM tunnel construction. The measured shotcrete rebound was about 7.2% in average which was about half the allowable rebound (15%), showing shotcrete spraying was performed well. Based on the measurement of excavated tunnel shape, average overbreak was about 28.5cm after tunnel excavation by drill and blasting method. This was about 260% of allowable overbreak. In addition, due to the rebound and overbreak actual amount of shotcrete used in the tunnelling work was about 116.5 % of the designed value. According to the field measurement the ratio of actual shotcrete to designed value showed some relation with standard support pattern, but the size of overbreak did not show the correlation with standard support pattern. Hence current design specifications stating the size of overbreak based entirely on standard support pattern should perhaps be reestablished. The insight into the design guideline regarding overbreak and shotcrete.

• Proceedings of the Korea Information Processing Society Conference
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• 2008.05a
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• pp.73-75
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• 2008

현대는 시뮬레이션을 통하여 많은 모의 훈련을 대체하고 있다. 시뮬레이터는 고유의 훈련 임무를 수행하기 위하여 기획, 제작 되어진다. 하지만 현대와 같은 종합적인 입체훈련 체계는 고유의 훈련 임무 이외에 개개의 시뮬레이터의 임무가 가상의 종합 시뮬레이션 환경에 참가한 통합 훈련 체계의 필요성을 야기하게 되었다. 또한 각각의 시뮬레이터의 기능은 보다 세분화 되었으며 높은 성능을 요구하게 되었다. 현재 KA-32 헬기 시뮬레이터 영상 프로그램을 제작하고 있는 한국소프트스페이스(주)는 독립적인 시뮬레이터들에 HLA(High Level Architecture)를 적용하여 하나의 종합 훈련 시스템을 구축하였다. 고유의 임무를 지닌 시뮬레이테는 각각의 임무를 가상의 종합 훈련 환경에 참가하여 서로간의 훈련 효과를 극대화 시켜화 시켜준다. HLA 기반의 종합 훈련 시스템의 RTI(Run-Time Infrastructure)는 Pitch 사의 pRTI를 사용하였으며, 가상의 종합 시뮬레이션 환경의 핵심이 되는FOM(Federation Object Model)은 호환성을 및 모든 객체의 표현을 위하여 RPR FOM(Real-time Reference FOM)을 사용하였다. 본 종합 훈련 시스템에서는 각각의 시뮬레이션간에 최고의 성능을 내기 위하여, 기능 세부화 하여 구성하였다. Terrion 사의 FLAMES는 종합 훈련 시스템의 시뮬레이션 진행/설정 및 분석을 담당하며, Mantis는 훈련 상황을 사실감 있는 3 차원 영상으로 참가자에게 전달하여 준다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.15-16
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• 2023

In this paper, we aimed to develop a new method for diagnosing the depth of neutralization in architectural and civil engineering structures using the core drilling method, which combines the speed of drilling with the accuracy of core ringing. When compared to the drilling method, the core drilling method showed a lower measurement deviation of 1-2mm (7.6%) in confirming the depth of neutralization. This is believed to be a result of potential interference during the sample collection process in the drilling method, where the drill may pass through aggregates, leading to overestimation, as indicated in previous studies. The rapid evaluation of neutralization using the core drilling method serves as an alternative to address the issues associated with both drilling and core ringing methods in diagnosing the depth of neutralization. It offers a solution to the inaccuracy caused by coarse aggregates and the cumbersome post-processing steps required for neutralization diagnosis. Our proposed technique aims to provide an accurate and expedited diagnosis of neutralization depth without the need for additional processes.

• Proceedings of the Korean Society of Crop Science Conference
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• 2022.10a
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• pp.167-167
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• 2022

Seed production of italian ryegrass has a problem of lodging during ripening and a decrease in quality due to difficulty in drying seeds during harvest. Therefore, in order to produce high-quality Italian ryegrass in paddy fields, it was carried out to reduce the density and solve the lodging problem through transplanting. In this experiment, Lolium multiflorum cv. Kowinearly was transplanted in autumn from a paddy field in Sindong-ri, Gwansan-eup, Jangheung-gun, Jeollanam-do. var. Kowinearly was made into a bed at 90 g/box and stacked in boxes. It was transplanted on October 27th after 2 days of germination at 30℃ and 15 days of seedling and greening. When transplanting, they were transplanted at intervals of 30×14cm. The existing cultivation method, drill seedling, was sowed at a level of 50 kg/ha, and both transplanting and drilling were carried out at a nitrogen fertilization rate of 45 kg/ha. The number of ears during transplant cultivation was 1,016/m² and the drilling tended to be higher at 2,278/m², but this was probably due to the difference in seeding amount. The seed number of an ear tended to be 56% higher in transplantation, which had a significant impact on yield. The seed yield was 2,096 ka/ha in transplantation, which was 21% higher than that of drilling. When looking at the relationship with weed occurrence, there were areas where all the weeds, such as amul foxtail, occurred due to the low density. Even in the same transplanting area, the seed yield was about 1,000kg/ha less in the area where the weeds were abundant. It seems that weed management is important in paddy cultivation. Therefore, it seems necessary to develop an exclusive herbicide for Italian ryegrass cultivation.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.6 no.2
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• pp.81-92
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• 2001

According to analyses of high-resolution seismic profiles (air gun, sparker, and SBP) and a deep-drill core(YSDP 105) in the mid-eastern Yellow Sea, stratigraphic and geoacoustic models have been established and seismo-acoustic modeling has been fulfilled using ray tracing of finite element method. Stratigraphic model reflects seismo-, litho-, and chrono-stratigraphic sequences formed under a significant influence of Quaternary glacio-eustatic sea-level fluctuations. Each sequence consists of terrestrial to very-shallow-marine coarse-grained lowstand systems tract and tidal fine-grained transgressive to highstand systems tract. Based on mean grain-size data (121 samples) of the drill core, bulk density and P-wave velocity of depositional units have been inferred and extrapolated down to a depth of the recovery using the Hamilton's regression equations. As goo-acoustic parameters, the 121 pairs of bulk density and P-wave velocity have been averaged on each unit of the stratigraphic model. As a result of computer ray-tracing simulation of the subsurface strata, we have found that there are complex ray paths and many acoustic-shadow zones owing to the presence of irregular layer boundaries and low-velocity layers.

• Journal of the Society of Disaster Information
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• v.15 no.3
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• pp.358-366
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• 2019

Purpose: This paper aims to clarify the problems and to examine the improvement methods by investigating the management condition of local-designated cultural property of which management is relatively poor in comparison with state-designated cultural heritage. Method: In order to grasp the management situation of the local-designated cultural heritage, a research on cultural heritage management situation and problems will be carried out with 35 cultual heritages in Goryeong-gun. Also, the improvement methods about the property type vulnerability on the basis of interview with cultual property managers, fire-fighting officers and civil servants, etc. Results: Local cultural heritages were investigated to be very vulnerable to the fire of wooden buildings, the theft of movable cultural heritages, and the effects of wind and water damage. It is because cultural heritages are scattered over wide areas fundamentally. As the result, it has difficulty in the patrols of police officers and fire fighters, and in the situation that it lacks disaster monitoring and CCTV for countermeasures to replace them, electronic security including fire hydrant, sensors, etc and fire extinguishing facilities and so on. It is difficult for local governments managing local-designated cultural heritages to enhance their management systems directly due to their lack of budget and manpower. Conclusion: In order to strengthen disaster and safety management system for the cultural heritages designated by local governments, they have to clarify disaster countermeasure task of fire fighting, police, and cultural heritage managers prepare their manuals, and systematize them through disaster drill mainly in local autonomous governments. Also, so as to establish a surveillance system every day, they have to enhance the community for local cultural heritage manage consisting of local volunteer fire departments, local voluntary disaster prevention organizations, volunteers, etc.