• 한국산학기술학회논문지
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• 제19권4호
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• pp.17-24
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• 2018

과거 홍수로 인한 침수피해가 자주 발생하였던 안성천 하류 저지대의 홍수-유출 특성을 파악하기 위해서 HEC-HMS 모형을 적용하였다. 모형은 SCS-CN 방법으로 손실계산을, Clark의 단위도법으로 강우의 직접유출 변환을, 지수함수적 감소방법으로 기저유량을, Musingum 방벙으로 하도추적을 하는 과정을 포함한다. 모형에서 매개변수는 중요한 역할을 하므로, 최적화 기법을 시행착오법과 병행하여 최적화 변수를 도출하였다. 또한, 민감도 분석을 통하여 도달시간, 저류함수, 기저유량 관련 상수들이 모형에 미치는 영향을 파악하였다. 도달시간은 첨두유량 발생 시각에 영향을, 저류상수는 첨두 유량의 증감에 영향을 기저유량 감소비는 수문곡선 하강부의 기울기에 영향을 미치는 것으로 나타났다. 최적화 과정을 통하여 모형 보정을 거친 변수를 사용하여 2건의 강우 사상에 대하여 유출모의를 수행하여 실측 자료와 비교를 하였으며, 유출체적, 첨두유량, 첨두시각을 포함한 중요 수문현상에 대하여 상당히 정확하게 모사하는 것으로 나타났다. 따라서, 본 연구의 결과는 정책입안자가 홍수관리대책을 수립하는 데 유용한 도구로서 사용되어 질 수 있을 것으로 사료된다.

• 한국미생물학회:학술대회논문집
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• 한국미생물학회 2002년도 추계학술대회
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• pp.59-62
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• 2002

The role of a TolC homologue in the virulence of Vibrio vulnificus, a marine bacterium causing serious wound infection and fulminant septicemia in persons with underlying conditions, has been studied. TolC, an outer membrane protein, has been implicated in a variety of bacterial functions including export of diverse molecules ranging from large proteins to antibiotics. A homologue of the tolC gene of V. cholerae, which has been shown to be required for bile resistance, cytotoxicity and colonization of this organism, was identified in the partially determined genome sequence of V. vulnificus. To determine the role of TolC in the virulence of V. vulnificus, a TolC-deficient (TD) mutant was isolated by in vivo allelic exchange. Compared with the parent strain, the TD mutant was more sensitive to bile, and much less virulent in mice challenged subcutaneously. This mutant was noncytotoxic to the HEp-2 cells, but its metalloprotease and cytolysin activities in the culture supernatant were comparable to the parent strain. In addition, the resistance of the TD mutant to human serum bactericidal activity as well as its growth in either human or murine blood was not affected. Collectively, our data suggest that TolC may be involved in colonization and/or spread of V. vulnificus to the blood stream, probably by secreting a cytotoxin other than the cytolysin.

• 한국지하수토양환경학회:학술대회논문집
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• 한국지하수토양환경학회 2006년도 총회 및 춘계학술발표회
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• pp.183-193
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• 2006

Several metalliferous and coal mines, including Seojin and Okdong located at the Kangwon province, were abandoned or closed since 1989 due to the mining industry promotion policy and thus disposed an enormous amount of mining wastes without a proper treatment facilities, resulting in water and soil pollution in the downstream areas. However, no quantitative assessment was made on soil and water pollution by the transport of mining wastes such as acid mine drainage, mine tailing, and rocky waste. In this research, total and fractional concentrations of heavy metals in mining wastes were analyzed and accordingly the degree of water and soil pollutions in the stream area were quantitatively assessed employing the several pollution indices. Concentrations of Ni, Cd, and Pb in soils near the abandoned coal mine areas were 1,240.0, 25.0 and 1,093.0 mg/kg, respectively, and these concentrations were higher than those in soils near the closed metalliferous mine areas. Also Cu concentrations in soils near the tailing dams were about 1967 mg/kg, which is considered as very polluted level. Results demonstrated that soil at the abandoned mine areas were highly contaminated by AMO, tailing, and effluents of the mining wastes. Therefore, a prompt countermeasure on the mining waste treatment and remediation of the codntaminated water and soil should be made to the abandoned or closed metalliferous and coal mines located at the abandoned mine area.

• 상하수도학회지
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• 제25권2호
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• pp.265-274
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• 2011

Nowadays, the importance of non-point source pollution treatment is being emphasized. Especially, the easy runoff characteristic of highly concentrated pollutants in the roads makes the circumstance more complicated due to impermeability of roads. When the pollutants flow into steam it could make water quality in stream worse and it also causes a bad influence in the aquatic ecosystem because the effluents of rainfall-runoff may contain indecomposable materials like oil and heavy metals. Therefore, we tried to figure out the property of non-point source pollution when it is raining and carried out an assessment for the property of runoff for non-point source pollution and EMC (Event Mean Concentrations) of the essential pollutants during this study. As the result of the study, the EMC was BOD 5.2~21.7 mg/L, COD 7.5~35.4 mg/L, TSS 71.5~466.1 mg/L, T-N 0.682~1.789 mg/L and T-P 0.174~0.378 mg/L, respectively. The decreasing rate of non-point pollutant in Chungyang-Hongsung road indicates the maximum decrease of 80% until 5 mm of rainfall based on SS concentration; by the rainy time within 20~30 minutes, the decreasing rate of SS concentration was shown as 88.0~97.6%. Therefore it was concluded that it seems to be possibly control non-point pollutants if we install equipments to treat non-point pollutants with holding capacity of 30 min. It is supposed that the result of this study could be used for non-point pollutants treatment of roads in Chungyang-Hongsung area. We also want to systematically study and consistently prepare the efficient management of runoff from non-point source pollution and pollutant loading because the characteristics of non-point source pollution runoff changes depending on different characteristics and situations of roads and rainfall.

• 한국농공학회논문집
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• 제47권6호
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• pp.83-92
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• 2005

Natural environment of the Wolgokri stream watershed, located in Chuncheon, Gangwon province, Korea, has been well preserved as a traditional agricultural watershed. To analyze characteristics of NPS pollution generated from an mountainous agricultural watershed, the flow and water qualities of the study watershed were monitored and were analyzed to estimate pollution loads. Annual runoff volume ratio was $70.4\%$. Concentrations of T-N, T-p, COD, and TOC were higher when monthly rainfall was between $0\~30mm$ than those when monthly rainfall was between $30\~70mm$. However, the concentrations varied considerably when monthly rainfall was higher than 100mm. The flow weighted mean concentrations(mg/L) of BOD, COD, TOC, $NO_3-N$, T-N, T-P and SS were 1.96, 2.72, 3.32, 1.41, 4.70, 0.187 and 13.36, respectively. The BOD, SS, T-N and T-P loads of July, 2004 were $48\%,\;17\%,\;51\%\;and\;32\%$ of annual load, respectively. The BOD, COD, TOC, $NO_3-N$, T-N, T-p, and SS loads (kg/ha) from Mar. 2004 to Apr. 2005 were 19.09, 26.55, 32.39, 13.85, 45.92, 1.887 and 130.18, respectively. The highest concentrations of BOD, NO3-N, T-N, T-p, SS, COD and TOC were found before the flow reached the peak runoff, possibly due to the first flushing effect. Generally, pollution loads of the Wolgokri watershed were not that significant. Phosphorus load, however, was higher enough to cause eutrophication in the receiving water body It was recommended that best management practices need to be implemented to reduce phosphorus sources.

• 한국환경복원기술학회지
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• 제8권1호
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• pp.45-51
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• 2005

Total phosphorus(TP) removal was examined in a surface-flow wetland constructed in April 2003 during its initial operating stage from June to November 2003. Its dimensions were 87mL by 14mW. It was a part of a four-wetland-cell treatment system constructed near the Kohung Estuarine Lake located in the southern part of Korea. Effluent from a night soil treatment plant was discharged into the wetland and purified effluent from the wetland was discharged into Sinyang Stream flowing into the Lake. Cattails(Typha angustifolia ) from natural wetlands were cut at about 40 cm height and transplanted into the wetland. An average of 25.0$m^3$/day of effluent flowed from the plant into the wetland. Water depth was maintained about 0.2m and hydraulic detention time was about 5.2 days. Average heights of the cattail stems in June and October 2003 were 47.2 and 164.6cm, respectively. The average number of stems was 10.2 stems/$m^2$ in June 2003 and 18.8 stems/$m^2$ in October 2003. Average temperature of influent and effluent ranged 23.4 and $24.2^{\circ}C$, respectively. The average TP concentrations of influent and effluent were about 1.31, 0.50mg/L, respectively. TP loading rate of influent into the wetland averaged 26.81mg/$m^2$, day and average TP loading rate of effluent was 10.04mg/$m^2$, day. Monthly average TP removal by the wetland during the warm growing season of cattails(June to September) ranged 16.28~19.57mg/$m^2$, day and during the cold senescent period (October to November) ranged 12.62~13.90mg/$m^2$, day. TP removal in the wetland continued during the cold winter months and was primarily done by sedimentation and precipitation of phosphorus rather than phosphorus absorption by cattails and microorganisms.

• 한국환경복원기술학회지
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• 제8권1호
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• pp.37-44
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• 2005

Nitrate($NO_3-N$) and total nitrogen(TN) removal by a reed wetland with open water(Wetland 1) was compared with that of a reed wetland without open water(Wetland 2) from March to October 2002. The two wetlands were 25mL by 6mW. An open water area, 3mL by 6mW was designed at the middle of Wetland 1. Reeds(Phragmites australis) were transplanted into the wetlands in June 2000. Water of Sinyang Stream flowing into the Kohung Estuarine Lake located in the southern part of Korea was pumped into a primary treatment pond, whose effluent was discharged into the secondary pond. Effluent from the secondary pond was funneled into the wetlands. Inflow into the wetlands averaged about 20.0$m^3$/day and their hydraulic retention time was approximately 1.5 days. Average $NO_3-N$ removal by Wetland 1 was 117.61mg/$m^2{\cdot}day$ and that by Wetland 2 was 106.39mg/$m^2{\cdot}day$. $NO_3-N$ removal efficiency of Wetland 1 and 2 was 37% and 34%, respectively. TN removal by Wetlands 1 and 2 averaged 226.80 and 214.54mg/$m^2{\cdot}day$, respectively. TN abatement efficiency of Wetland 1 was 43% and that of Wetland 2 was 40%. $NO_3-N$ removal efficiency of Wetland 1 was significantly higher(p=0.038) than Wetland 2. TN removal efficiency of Wetland 1 was also significantly higher(p=0.044) than Wetland 2. The wetland with open water was more efficient for removal of $NO_3-N$ and TN than one without.

• 한국통신학회논문지
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• 제32권12A호
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• pp.1311-1319
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• 2007

본 논문에서는 UHF 대역 RFID 수동형 태그의 디지털 회로부 구현을 위한 VHDL 설계과정을 보인다. 태그의 동작은 EPCglobal Class1 Gen2 표준을 지원하며 합성과 구현과정을 거친 타이밍 시뮬레이션 결과를 통해 검증하였다. 수 미터의 인식거리로 인해 Frame-Slotted Aloha를 사용하는 환경에서, 단위시간당 태그 인식률을 향상시키기 위해서는 리더 명령에 대한 빠른 처리와 응답을 할 수 있는 디지털 회로 설계가 필요하다. 본 설계는 Pipeline 처리 구조를 기반으로 직렬 입력 신호에 대한 응답지연의 최소화를 목표로 하였다. 또한, 효율적인 다중 접속 명령들의 처리와 태그의 데이터 전송 속도의 오차를 낮추기 위해 리더의 Preamble과 PIE 디코딩을 위한 샘플링 과정을 제안하였다. FPGA 검증을 위한 Place & Route 후 다중 태그 상황을 감안한 테스트 벤치 시뮬레이션 결과, 표준상의 최대 송수신 데이터 전송 속도에서 디코딩 및 인코딩 을 위한 최소 요구 시간 보다 빠른 처리 결과를 확인 할 수 있었다.

• 해양환경안전학회지
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• 제19권1호
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• pp.85-92
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• 2013

최근 기후변화를 초래하는 화석연료의 사용을 감축하는 세계적 추세와 함께 에너지의 안정적 공급을 위해 많은 노력이 요구되고 있다. 또한 2012년부터는 500 MW 이상의 전기를 생산하는 에너지사업자는 신재생에너지 의무할당제의 적용을 받는다. 조류자원은 최근 각광을 받고 있는 신재생에너지이며, 이러한 조류자원은 매우 크지만 제한된 지역에 분포하고 있으므로 조류에너지를 효과적으로 이용하기 위해서는 반드시 기술적, 경제적인 측면의 평가가 요구된다. 그러므로 본 연구에서는 부남군도 해역에 부존하는 조류자원 실용화 기술개발을 위하여 조류에너지원에 대한 자료수집 등의 현황분석과 수치모델을 이용한 시뮬레이션 등을 통하여 조류에너지 분포도를 조사하고 이용 가능한 연간 에너지 생산량을 산정, 조류발전기를 모듈화 하여 최적의 조류발전단지 구성기술을 개발하고자 한다.

• Korean Chemical Engineering Research
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• 제45권4호
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• pp.319-327
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• 2007

소각은 유기성 유해폐기물에 대해 가장 발달된 유용한 처리기술로 인정되어 왔다. 그러나 PCBs와 같이 유해한 폐기물의 처리를 위한 소각로의 부지확보나 인허가가 유해한 대기오염 물질의 배출에 대한 주민의 우려로 용이하지 않다. 최근에 많은 소각 대체기술들이 개발되어 왔으며 이 기술들은 소각에 비해 다이옥신이나 퓨란과 같은 유해한 물질의 배출이 적어 주민의 우려를 완화시킬 수 있다. 본 논문에서는 다양한 유해폐기물의 종류에 대해 현재 적용이 가능한 소각 대체기술들을 검토하였다. 다양한 범주의 비열처리 및 열처리 소각 대체기술들을 공정운전조건, 적용대상 폐기물 및 이차폐기물 발생특성의 관점에서 평가하고 몇 가지 소각 대체기술들에 대해서는 공정의 운전원리에 대해 자세히 설명하였다.