• Geophysics and Geophysical Exploration
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• v.25 no.3
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• pp.129-139
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• 2022

Analog-based streamers for ultra-high-resolution seismic surveys are capable of additional noise ingress in water, but the specifications cannot be expanded through interconnections. Foreign-produced digital streamers have been introduced and used primarily at domestic research institutes; however, the cost is high and smooth maintenance is challenging. This study investigates the localization of ultra-high-resolution digital streamers capable of high-resolution imaging of a geological structure. A digital streamer capable of 24-bit, 10 kHz digital sampling of up to 64 channel data was developed through research and development. Various quantitative specifications of the system were designed and developed close to the benchmark model, Geometrics' GeoEel streamer, and the number of modules that make up the system was drastically reduced, reducing development costs and making it easier to use. The field applicability of the developed streamer system was evaluated in an in situ experiment conducted in the waters around the Port of Yeong-il Bay in Pohang in April 2022.

• Review of KIISC
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• v.18 no.4
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• pp.42-48
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• 2008

IPTV 서비스는 인터넷 기반의 TV서비스를 말하는 것으로, 부가서비스로서 온라인게임, 전자상거래, 인터넷 전화를 제공하는 융복합형 신규 서비스이다. 인터넷 환경에서 TV를 서비스를 제공하기 위한 관련 표준화가 ITU-T IPTV-GSI에서 활발히 이루어지고 있으며, 보안 분야에서는 IPTV 보안 요구사항, 안전한 트랜스코더블 기법, IPTV에서의 키관리 기법 등의 표준화가 진행 중에 있다. 또한 IPTV 서비스에서의 실시간 방송을 위한 주요 핵심 통신기술인 멀티캐스트에 대한 보안 기술 표준화 또한 진행중에 있다. 중계 기반 멀티캐스트 전송 규격인 X.603.1이 2007년 2월에 표준으로 제정되었고, 이에 대한 보안 규격으로서 현재 ‘중계기반 멀티캐스트 보안 규격’이 ISO/IEC와 공동으로 표준화가 진행 중이며, ‘멀티캐스트 보안 요구사항 및 프레임워크’가 ITU-T SG17/Q9 응용서비스 보안분과에서 진행 중에 있다. 멀티캐스트 보안 관련 기술 표준화는 2010년 경에 완료될 것으로 보이며, 표준제정시 IPTV에서 전송기술로 X.603.1을 사용시 보안규격으로서 적용될 것으로 전망된다.

• FLOWER RESEARCH JOURNAL
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• v.19 no.2
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• pp.103-109
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• 2011

This study was conducted to develop mass production method by proper cutting time, and the concentrations of plant growth regulators of Spiraea spp. Plants of hard wood was cut on March 3th, the rooting rate in S. salicifolia and S. cantoniensis was 11.3% comparatively higher than that about 5% in S. trichocarpa, S. miyabei, S. japonica, S. thunbergii and S. fritschiana. The rooting of control was 6.0%, however the $125{\sim}1,000mg{\cdot}L^{-1}$ IBA or NAA for 3 hour soaking was above 15.0% in the S. salicifolia. Therefore soaking in $125mg{\cdot}L^{-1}$ of IBA or NAA solution was recommended before cutting. The proper cutting time for soft wood from May 7 to September 17 in S. trichocarpa, S. cantoniensis, S. prunifolia, and S. thunbergii was September 17 when the soft stem was changed hard and the temperate was proper for rooting, high and low, $25{\pm}3^{\circ}C$ and $18{\pm}3^{\circ}C$. The rooting of September 17 was above 70% in S. salicifolia and S. fritschiana. However, the rooting from middle of May to early August was low below 20% in all the genus of Spiraea.

• Proceedings of the Korea Water Resources Association Conference
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• 2022.05a
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• pp.105-105
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• 2022

섬진강댐은 100년빈도 홍수에 대응토록 설계되어 홍수조절 능력이 타 다목적댐 대비 상대적으로 취약함에 따라 댐운영 체계 개선이 필요하다. 이에따라 K-water는 홍수시 피해를 최소화 할 수 있도록 댐운영과 관련한 홍수대응 체계를 개선하였다. 주요 개선대책은 섬진강 홍수조절용량 추가확보, 홍수기 강우특성을 고려한 홍수조절, 하류주민 및 기관과 소통에 기반한 정보 공유체계 확립, 디지털 트윈 기반 댐 운영 의사결정시스템 구축이다. 섬진강댐의 건설홍수조절용량은 3천만m³으로, 타 다목적댐 설계빈도인 200년 대비 홍수대응 능력이 미흡하다. 이에따라, 섬진강댐은 '21.1월부터 '22.12월까지 홍수기 제한수위를 기존 197.7m에서 2.5m 낮춘 194.0m로 시범운영하고 있다. 이를통해 기존 3천만m³에서 9천만m³까지 6천만m³의 홍수조절용량을 추가 확보하였다. 이와 연계하여 홍수기 동안 섬진강댐 운영수위 기준을 별도 수립하여 홍수기 전·후반으로 나누었으며, 전반기(~7/31)는 '20년 홍수상황에서 발생한 더블피크 집중호우(360mm)에 대응가능한 홍수조절능력을 확보하고, 후반기(8/1~)는 홍수조절능력을 최대한 확보함과 동시에 차년도 용수공급을 대비할 수 있도록 운영수위를 개선하였다. 그간 수문방류 정보는 '댐 관리규정'에 따라 방류개시 3시간 전까지 방류계획을 하류지역의 지자체 및 주민에게 통보하였으나, 하류주민들이 충분히 사전준비하기에 시간적으로 부족하다는 의견을 제시함에 따라 수문방류 24시간전 사전 안내토록 '수문방류 예고제'를 도입, 시행하였다. '댐 홍수관리 소통회의'를 통해 댐 운영기관-정부기관-주민이 댐 운영에 대한 전반에 대해 함께 공유하고 운영 제약사항 및 개선사항을 공동 발굴하여 대책을 마련하는 체계를 구축하였다. 댐 운영 개선사항과 더불어 댐방류 의사결정시, 실시간 하류하천 상황에 대한 확인이 어려움에 따라, 3D기반 의사결정 지원시스템인 Digita Twin Platform을 개발 및 구축하여 '22년부터 섬진강댐 운영에 시범적용을 추진하고자 한다.

• Korean Journal of Environmental Biology
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• v.26 no.3
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• pp.145-158
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• 2008

To assess the source of oyster (Crassostrea gigas) and clam (Ruditapes phillippinarum), phytoplankton community structures in the water column and sediment, including the composition of phytoplankton in oyster and clam digestive organs were investigated bimonthly from December 2006 to June 2007 in the Taeahn coastal waters. During the sampling period, water temperature and salinity varied from 7 to 23$^{\circ}C$ and 34 to 35 PSU, respectively. Total phytoplankton abundances at St. O in the water column were higher than those at St. J, whereas total phytoplankton abundances at St. O in the sediment were lower. In addition, total phytoplankton abundances in the water column and sediment were observed to be relatively higher in February and April 2007. Among the diatoms, Paralia sulcata was always dominant, accounting for 41$\sim$87% of total phytoplankton, except St. J for February 2007 during the sampling period. The following phytoplankton compositions observed in the digestive organs of oyster and clam appeared: diatoms such as genus Paralia, Navicula, Melosira and Coscinodiscus, Silicoflagellate Dictyocha, dinoflagellates Prorocentrum and Dinophysis. Phytoplankton compositions observed in the digestive organs of oyster and clam corresponded relatively well with the species composition appeared in the water column and sediments of each season. A significant relationship was found between individual weight of oyster or clam and their digestive organs weight, while there was not a close correlation with total phytoplankton amount. We suggest that P. sulcata always dominated as one of important the food source of oyster and clam in the marine ranching ground of Taeahn coastal waters.

• 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 the Korea Academia-Industrial cooperation Society
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• v.22 no.5
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• pp.162-170
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• 2021

The Smart City Living Lab is becoming important as a local innovation platform to develop urban solutions. In January 2018, the 4th industrial innovation committee, which was a direct subordinate from the president, empathized citizens' participation and their roles within the Smart City [Urban Innovation and Future Growth Engine-Creating Smart City Strategy]. This was the starting point of the living lab. The central government and local governments have been promoting various types of living labs to encourage citizens to participate. On the other hand, due to the lack of systematic concepts and theories for practicing and structuring living labs, the practice is not performed well. This study aimed to develop systematic approaches and implementation methods of the public-led Smart City Living Lab. The Full-cycle Smart City living Lab model was designed by integrating smart city living lab work processes, as suggested in the standards of the national land plan, double design diamond framework, which is a type of innovative design methodology, and design thinking process. The entire cycle Smart City living lab model requires four components to practice the living lab, such as framework, module, process, and methodologies. In the future, this model is expected to be incorporated in the Smart City Living Lab.