• Proceedings of the Korea Water Resources Association Conference
• /
• 한국수자원학회 2009년도 학술발표회 초록집
• /
• pp.1533-1536
• /
• 2009

기후변화에 따른 빈번한 태풍과 집중호우로 인해 지속적으로 피해규모가 증가하고 있으며 점차 다양한 지역에서 피해가 나타나고 있다. 과거 태풍 루사나 매미의 경우 도시유역에서 주요 피해가 발생하여 대규모 피해를 야기하였으나 2006년 발생한 태풍 에위니아의 경우 집중호우로 인한 배수문제, 산사태로 인한 토석류 발생과 이에 따른 도로 및 하천 유입으로 피해가 나타났다. 이러한 피해는 남해안 및 영남지방, 강원 영서지방에서 주로 발생한 것으로 과거 피해 유형과 차이가 난다. 기존 하천 중심의 치수대책만으로는 다양한 지역특성을 고려한 치수계획을 종합적으로 수립할 수 있는 한계가 발생하며 이에 따라 국토해양부(2001)는 수자원 장기종합계획에서 하도와 유역 시스템을 함께 고려하는 유역종합치수정책을 제안하였다. 홍수피해잠재능은 수자원장기종합계획(2001)에서 처음 제시된 개념으로 면 개념을 도입하여 공간적 비교가 가능하고, 단위구역의 치수특성 및 사회경제적 가치를 평가할 수 있도록 개발된 지수(이승종, 2006)이며, 치수안전도 설정을 위한 가장 중요한 개념으로 활용되고 있다. 그러나 최근에 제시된 개념으로 아직 이론적 기반이 미흡하며 지속적인 연구를 통해 수정된 개념이 제시되고 있는 실정이다. 본 연구에서는 유역종합치수계획 등 국가 치수정책을 수립하기 위해 중요한 개념인 홍수피해잠재능과 치수안전도의 치수계획 활용 사례를 조사하여 지역특성별로 유역분할기법을 조사 정리하였으며 국외 사례를 분석하여 유역분할기법의 발전 방향을 제시함으로써 유역단위 맞춤형 치수계획 수립을 위한 기초 자료를 제공하고자 한다.

• Restorative Dentistry and Endodontics
• /
• 제24권1호
• /
• pp.116-128
• /
• 1999

치근흡수 연구에서 치아재식을 위한 적당한 동물모델을 찾는일은 대단히 중요하다. 본 실험에서는 쥐 대구치의 발치 및 재식을 통해서 치근흡수가 발현되는 모양을 관찰했다. 모두 20마리의 쥐(30일생)에게 0.4% ${\beta}$-APN(aminoproprionitrile)가 포함된 분말용쥐사료를 5일간 먹인후 케타민 마취후 상악좌우측 제일대구치를 손상을 최소화하여 발치 하였다. 발거된 쥐치아는 0.02M Tris-HCl로 표면처리하여 부착치근막을 제거한후 파라핀팍스로 치근단을 밀폐 하여 재식하였다. 재식후 1, 2, 4, 6, 8 및 12일이 경과된 후 심장관혈을 통하여 쥐를 희생시킨후 3% glutaraldehyde가 포함된 EDTA에서 탈회한후 Epon 포매 하였다. 모든 시편은 유리칼을 사용하여 1미크론 두께로 절편한후 veronal acetate buffer에 녹인 1% toluidine blue로 염색하였다. 파치세포양 세포에 의한 치근흡수는 재식 5-7일후 처음 관찰되었다. 재식 12일후에는 치근 전체에 걸친 광범위한 치근흡수가 관찰되었다. 이상의 결과 ${\beta}$-APN을 포함한 쥐사료 식이요법은 쥐 상악제일대구치의 발치와 재식을 용이하게 하여 일정한 치근흡수를 발현시키는데 많은 도움이 된 것으로 판단되었다.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.800-803
• /
• 2007

Gasification has been regarded as a core technology in dealing with environmental pollutants and in obtaining higher efficiency for power generation. Among several ways in utilizing produced syngas from gasification, power generation would be the most prominent application. Syngas from coal was applied to the readily available LPG engine from automobiles. Main purpose was to identify the combustion characteristics in the modified gas engine when using syngas of low heating value and to test the modification optionsin the LPG gas engine. Gas engine rpm and the corresponding flue gas composition were measured for each syngas input condition. Results showed that even with syngas at the heating value of $1300{\sim}1800$ kcal/$Nm^3$ corresponding to the $6{\sim}7%$ of LPG heating value, gas engine operated successfully only with the problems of high CO and oxygen concentrations in the flue gas.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 춘계학술대회
• /
• pp.804-807
• /
• 2007

The acid gas removal (AGR) system was designed and installed to remove $H_2S$ in coal syngas in the pilot-scale coal gasification system for producing chemicals like Dimethyl Ether(DME). The syngas from the coal gasification at the rate of $100{\sim120$ $Nm^3$/hr included pollutants such as fly ash. $H_2S$, COS, $NH_3$, etc. The designed temperature and pressure of the AGR system are below 50oC and 8 kg/$cm^2$. Fe-chelate was used as an absorbent. $H_2S$ was stably removed below 0.5 ppm in the AGR system when the concentration of $H_2S$ was $150{\sim}450$ ppm. The pH of Fe-chelate solution was also stably maintained between $8{\sim}9$. FeMgO absorbent was also tested to remove $H_2S$ in the lab-scale AGR system and $H_2S$ was also removed below 0.5 ppm in the initial operation.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2006년도 추계학술대회
• /
• pp.83-86
• /
• 2006

In this study, the syngas producing facility that consists of pulverized coal feeding/gasification and hot gas clean-up system was tested for Indonesian subbituminous coal. And the DME conversion facilities have been developed and tested for converting syngas to DME by reactions with catalysts. So, the entrained-bed slagging type pi lot scale coal gasifier was operated normally in the temperature range of $1,400{\sim}1,450^{\circ}C,\;7{\sim}8kg/cm^2$ pressure. And Roto middle coal produced syngas that has a composition of $36{\sim}38%$ CO, $14{\sim}16%\;H_2,\;and\;5{\sim}8%\;CO_2$. Particulates in syngas were 99.8% removed by metal filters. $H_2S$ composition in syngas was also desulfurized by the Fe chelate system to yield less than 0.1 ppm level. When the clean syngas $70{\sim}100 Nm^3/h$ was provided to DME conversion rector, normally operated in the temperature range of $230{\sim}250^{\circ}C$ and $60kg/cm^2$ pressure, 4.5% DME was yielded.

• Korean Chemical Engineering Research
• /
• 제53권1호
• /
• pp.111-115
• /
• 2015

To produce patterns with high resolution in gravure printing, it is important to increase ink transfer ratio. The ink which has higher affinity with substrate can be transferred more from the roll to the substrate due to the good wettability between ink and substrate. However, it is difficult to evaluate the affinity between the substrate and the ink which is viscoelastic in nature. In this study, we suggest a practical method to evaluate the interfacial interaction between the ink and various substrates.

• 한국신재생에너지학회:학술대회논문집
• /
• 한국신재생에너지학회 2007년도 추계학술대회 논문집
• /
• pp.437-440
• /
• 2007

Gasification converts coal and other feedstocks into a very clean and usable gas, called syngas, that can be used to produce a wide variety products such as electricity, chemicals, transports fuels, hydrogen production, etc. This paper was studied the gasification performance effects with the variation of the gasification operating parameters such as the feeding amounts of oxygen, steam and coal. When $O_2/coal$ ratio was below 0.8, $H_2$ mole % was increased as increasing $O_2/coal$ ratio. CO mole % was increased when $O_2/coal$ ratio was below 1.2 as increasing the $O_2/coal$ ratio. As increasing steam/coal ratio, $H_2$ mole %was increased and CO mole % was decreased. The $O_2/coal$ and steam/coal ratio was $0.8{\sim}0.9$ and $0.0{\sim}0.4$, respectively, to keep the proper gasification condition that the gasifier temperature was $1300^{\circ}C{\sim}1450^{\circ}C$ and the cold gas efficiency was over 76%.

• Journal of the Korean Society of Fisheries and Ocean Technology
• /
• 제52권2호
• /
• pp.121-129
• /
• 2016

The distribution of eggs and larvae of mackerel, Scomber japonicus was examined in the coast of Jeju island, Korea in spring from April to May in 2013 and May to June in 2014. In the monthly variations of mean abundances, as a whole, mackerel eggs were observed abundantly in April, 2013, and mackerel larvae were observed abundantly in June, 2014. Especially, high densities over $5,000ind./1,000m^3$ of mean eggs abundances were observed in the eastern part of Jeju Island where is water temperature was over $18^{\circ}C$. It can be inferred that these areas were major spawning grounds of mackerel around Jeju island, and that it may be caused by influences of the Tsushima warm current.

• Korean Journal of Fisheries and Aquatic Sciences
• /
• 제49권5호
• /
• pp.689-693
• /
• 2016

Sargassum golden tides occurred in Shinan-gun and Jeju Island, Korea, between January and May 2015. In Shinangun, 5,180 tons of Sargassum were removed from 3,339 ha of coastline, while 20,000 tons were removed from Jeju Island. The huge floating masses of seaweed caused damage to fisheries in Shinan-gun including abalone sea cage, Pyropia and Saccharina farms off the southwest coast of Korea. Drifting Sargassum also washed ashore on Jeju Island. The species of Sargassum in these golden tides was identified as S. horneri (Turner) C. Agardh, based on morphology and molecular data, and it appears to have originated from the East China Sea. This is the first report on Sargassum golden tides causing damage to fisheries in Korea.

• Journal of the military operations research society of Korea
• /
• 제32권1호
• /
• pp.133-158
• /
• 2006

The change of information and communications technology affects into many parts of military battlefield as the future warfare will be information-oriented warfare, relying on information technology. The more IT-based military systems are deployed the more multimedia data traffic increase. To accommodate such user's requirements the bandwidth capacity of military communications network must be upgraded. The cost of upgrading network capacity is increasing as well. But there has no systematic estimation approach to analyze the amount of data traffic in the military network. In this paper we suggest an efficient data traffic estimation technique using network simulation with the respect of Input and output, scenario, toolset and technique, and experimental environments.