A Study on Characteristic for Manufacturing Immobilization of Green Body for Moist Particulate and Sludge-Type Radioactive Waste

Yongho Hong,Minsu Kim,Heekyung Kim,Hyoungmin Park,Dongchul Kim,Taekyu Lee,Byunggu Lee,Seonghun Yoon,Jeongsu Kim 한국방사성폐기물학회 2018 한국방사성폐기물학회 학술논문요약집 Vol.2018 No.05

Biodegradable Check Dam and Synthetic Polymer, its Experimental Evaluation for Turbidity Control of Agricultural Drainage Water

Kim, Minyoung,Kim, Seounghee,Kim, Jinoh,Lee, Sangbong,Kim, Youngjin,Cho, Yongho Korean Society of Soil Science and Fertilizer 2013 한국토양비료학회지 Vol.46 No.6

A drainage ditch is normally a component of drainage networks in farming systems to remove surplus water, but at the same time, it may act as a major conduit of agricultural nonpoint source pollutions such as sediment, nitrogen, phosphorus, and so on. The hybrid turbidity reduction system using biodegradable check dam and synthetic polymer was developed in this study to manage pollutant discharge from agricultural farmlands during rainfall events and/or irrigation periods. The performance of this hybrid system was assessed using a laboratory open channel sized in 10m-length and 0.2m-width. Various check dams using agricultural byproducts (e.g., rice straw, rice husks, coconut fiber and a mixture of rice husks and coconut fiber) were tested and additional physical factors (e.g., channel slope, flowrate, PAM dosage, turbidity level, etc.) affecting on turbidity reduction were applied to assess their performance. A series of lab experiments clearly showed that the hybrid turbidity reduction system could play a significant role as a supplementary of Best Management Practice (BMP). Moreover, the findings of this study could facilitate to develop an advanced BMP for minimizing nonpoint source pollution from agricultural farmlands and ultimately to achieve the sustainable agriculture.

Design and evaluation of an experimental system for monitoring the mechanical response of piezoelectric energy harvesters

Kim, Changho,Ko, Youngsu,Kim, Taemin,Yoo, Chan-Sei,Choi, BeomJin,Han, Seung Ho,Jang, YongHo,Kim, Youngho,Kim, Namsu Techno-Press 2018 Smart Structures and Systems, An International Jou Vol.22 No.2

Increasing interest in prognostics and health management has heightened the need for wireless sensor networks (WSN) with efficient power sources. Piezoelectric energy harvesters using Pb(Zr,Ti)O3 (PZT) are one of the candidate power sources for WSNs as they efficiently convert mechanical vibration energy into electrical energy. These types of devices are resonated at a specific frequency, which has a significant impact on the amount of energy harvested, by external vibration. Hence, precise prediction of mechanical deformation including modal analysis of piezoelectric devices is crucial for estimating the energy generated under specific conditions. In this study, an experimental vibrational system capable of controlling a wide range of frequencies and accelerations was designed to generate mechanical vibration for piezoelectric energy harvesters. In conjunction with MATLAB, the system automatically finds the resonance frequency of harvesters. A small accelerometer and non-contact laser displacement sensor are employed to investigate the mechanical deformation of harvesters. Mechanical deformation under various frequencies and accelerations were investigated and analyzed based on data from two types of sensors. The results verify that the proposed system can be employed to carry out vibration experiments for piezoelectric harvesters and measurement of their mechanical deformation.

Biodegradable Check Dam and Synthetic Polymer, its Experimental Evaluation for Turbidity Control of Agricultural Drainage Water

Minyoung Kim,Seounghee Kim,Jinoh Kim,Sangbong Lee,Youngjin Kim,Yongho Cho 한국토양비료학회 2013 한국토양비료학회지 Vol.46 No.6

A drainage ditch is normally a component of drainage networks in farming systems to remove surplus water, but at the same time, it may act as a major conduit of agricultural nonpoint source pollutions such as sediment, nitrogen, phosphorus, and so on. The hybrid turbidity reduction system using biodegradable check dam and synthetic polymer was developed in this study to manage pollutant discharge from agricultural farmlands during rainfall events and/or irrigation periods. The performance of this hybrid system was assessed using a laboratory open channel sized in 10m-length and 0.2m-width. Various check dams using agricultural byproducts (e.g., rice straw, rice husks, coconut fiber and a mixture of rice husks and coconut fiber) were tested and additional physical factors (e.g., channel slope, flowrate, PAM dosage, turbidity level, etc.) affecting on turbidity reduction were applied to assess their performance. A series of lab experiments clearly showed that the hybrid turbidity reduction system could play a significant role as a supplementary of Best Management Practice (BMP). Moreover, the findings of this study could facilitate to develop an advanced BMP for minimizing nonpoint source pollution from agricultural farmlands and ultimately to achieve the sustainable agriculture.

NHANES 데이터를 이용한 생활 패턴 기반의 우울증 예측 머신러닝 기법

김용호(Yongho Kim),김지하(Jiha Kim),우기문(Gimoon Woo),김형빈(Hyungbin Kim),박현희(Hyunhee Park) 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.6

본 논문은 NHANES(National Health and Nutrition Examination Survey) 에서 제공되는 설문조사 데이터 세트를 이용하여 PHQ-9 척도의 우울증 점수를 예측하는 방법을 제안한다. 일반 사용자가 접하기 어려운 의료 설문을 통해서 우울증을 진단받는 것 보다 쉽게 수집할 수 있는 생활 패턴 기반의 설문 응답을 가지고 예측을 할 수 있다는 장점이 있으면서. 본 논문에서 제안하는 기법은 다중 클래스 분류에서는 DNN 의 F1 score 가 60%로 가장 높은 성능이 나왔고 이진 클래스 분류에서는 Decision Tree F1 score 가 71%로 가장 높은 성능을 보였다.

Design and evaluation of an experimental system for monitoring the mechanical response of piezoelectric energy harvesters

Changho Kim,Youngsu Ko,Taemin Kim,유찬세,BeomJin Choi,한승호,YongHo Jang,Youngho Kim,Namsu Kim 국제구조공학회 2018 Smart Structures and Systems, An International Jou Vol.22 No.2

Increasing interest in prognostics and health management has heightened the need for wireless sensor networks (WSN) with efficient power sources. Piezoelectric energy harvesters using Pb(Zr,Ti)O3 (PZT) are one of the candidate power sources for WSNs as they efficiently convert mechanical vibration energy into electrical energy. These types of devices are resonated at a specific frequency, which has a significant impact on the amount of energy harvested, by external vibration. Hence, precise prediction of mechanical deformation including modal analysis of piezoelectric devices is crucial for estimating the energy generated under specific conditions. In this study, an experimental vibrational system capable of controlling a wide range of frequencies and accelerations was designed to generate mechanical vibration for piezoelectric energy harvesters. In conjunction with MATLAB, the system automatically finds the resonance frequency of harvesters. A small accelerometer and non-contact laser displacement sensor are employed to investigate the mechanical deformation of harvesters. Mechanical deformation under various frequencies and accelerations were investigated and analyzed based on data from two types of sensors. The results verify that the proposed system can be employed to carry out vibration experiments for piezoelectric harvesters and measurement of their mechanical deformation.

LC-MS/MS를 활용한 갈색거저리 유충 중 농약 353성분 동시 분석법 확립 및 유효성 검증

신용호 ( Yongho Shin ),김창조 ( Chang Jo Kim ),김이선 ( Leesun Kim ),이래근 ( Raekeun Lee ),김단비 ( Danbi Kim ),김정한 ( Jeong-han Kim ),경기성 ( Kee Sung Kyung ),노현호 ( Hyun Ho Noh ) 한국환경농학회 2021 한국환경농학회 학술대회집 Vol.2021 No.-

식용곤충 중 밀웜으로 잘 알려진 갈색거저리 유충(Tenebrio molitor larva)은 단백질 및 지방이 풍부하여 식용곤충 내 농약 다성분 분석법을 확립하기 위한 대표 시료로 적합하다. 본 연구에서는 갈색거저리 유충 중 농약 353성분의 동시 분석을 위해 acetonitrile-hexane 액액분배가 추가된 새로운 QuEChERS 전처리법 및 LC-MS/MS (liquid chromatography-tandem mass spectrometry)를 활용한 다성분 분석법을 검증하였다. 다성분 동시 분석을 위해 농약 353성분에 대한 LC-MS/MS (AB SCIEX Triple Quad^TM 5500 및 Exion LC^TM)의 MRM (multiple reaction monitoring) 조건을 확립하였고, 각 성분은 Halo C18 column (2.1 mm I.D. × 150 mm, 2.7 μm)을 사용하여 20분 이내로 분리하였다. 최종 확립된 전처리법에서는 갈색거저리 유충을 마쇄하여 균질화한 후 이중 5 g을 acetonitrile 12.5 mL로 추출하고 EN 15662 salt를 가한 후 원심분리하여 분배하였다. Acetonitrile-hexane 액액분배를 위해 상등액 6 mL에 hexane 4 mL을 가해 분배하였으며, 잔여 hexane은 새로운 acetonitrile (hexane 포화) 6 mL로 2회 액액분배하여 총 18 mL acetonitrile 추출액을 모았다. 추출액은 C18 sobent이 함유된 dSPE로 정제하고 원심분리한 다음 matrix-matching한 후, 이 중 2 μL를 LC-MS/MS에 주입하여 분석하였다. 분석법 검증 결과, 농약 353성분 모두 분석법상 정량한계(method limit of quantitation; MLOQ) ≤ 10 μg/kg으로 positive list system (PLS)에서 요구하는 기준(10 μg/kg)을 만족하였다. 검량선의 범위는 LOQ∼200 μg/kg이며, 모든 성분에 대해 r² ≥ 0.990으로 우수한 직선성을 보여주었다. 회수율 검증 결과 농약 320성분(전체 중 90.7%)이 10 및 50 μg/kg 두 수준 모두에서 회수율 70∼120% (RSD 20% 이하)였다. 검증된 분석법을 바탕으로 실제 갈색거저리 유충 시료 11점에 대해 농약 다성분 모니터링을 실시하여 분석법의 유효성을 입증하였다.

친환경 바이오폴리머를 이용한 탁도 및 유기물 제거 메커니즘 연구

김민영 ( Minyoung Kim ),김승희 ( Seounghee Kim ),김진오 ( Jinoh Kim ),이상봉 ( Sangbong Lee ),김영진 ( Youngjin Kim ),조용호 ( Yongho Cho ) 한국농공학회 2012 한국농공학회 학술대회초록집 Vol.2012 No.-

강우시 우수에 포함되어 하천 수계로 유입되는 비점오염원에 대한 관심은 나날이 증가하고 있다. 본 연구에서는 친환경 바이오폴리머를 이용한 탁도 및 유기물 관리에 대한 연구를 실시하였다. 각종 다른 형태 및 종류의 바이오폴리머를 이용, 교반실험을 실시하여 수질개선효과를 정량화하였다. 본 연구는 폴리머의 강우 유출수 내 응집, 침전 효과를 극대화시키기 위한 교반강도, 교반시간, 시료의 양 등을 선정하고, 유기물과 탁도 물질의 응집메커니즘 또한 파악하였다. 응집메커니즘 인공시험수의 Jar-test 실험 결과, 시험수의 탁도 및 유기물 제거율은 대부분 78% 이상 되는 것으로 나타났다. Eroded soil discharged from agricultural farmlands is a major water quality issue. Biopolymer, one of flocculants, has been demonstrated to reduce erosion and turbidity in runoff, but there is little information on the interactions between PAM properties and that of the water or suspended solids. This study investigated the removal efficiency of turbidity in agricultural runoff by various environmental-friendly biopolymer, This study tested biopolymer products for turbidity reduction in Kaolinite suspensions (as the dominant clay mineral (70~90%), a pH between 5~6, and very low organic matter). A series of jar-test experiments was conducted using different types of biopolymer at a given turbidity level. The turbidity reductions of greater than 78% were achieved for most cases. The result of this study would be valuable for the application of flocculant to control of agricultural runoff.

700 W급 독립형 소형풍력발전시스템 성능평가 방법 및 시험

김승주(SeungJoo Kim),김형근(HyungKun Kim),박찬혁(ChanHyuk Park),김용호(YongHo Kim),김상범(SangBeom Kim),문재원(JaeWon Moon) 한국태양에너지학회 2019 한국태양에너지학회 학술대회논문집 Vol.2019 No.10

농업 비점오염원 배출 관리를 위한 생분해성 체크댐 설계 및 활용

김민영 ( Minyoung Kim ),김승희 ( Seounghee Kim ),이상봉 ( Sangbong Lee ),김진오 ( Jinoh Kim ),김영진 ( Youngjin Kim ),조용호 ( Yongho Cho ) 한국농공학회 2013 한국농공학회 학술대회초록집 Vol.2013 No.-

기존의 최적관리기술(Best management practice, BMP) 중 하나인 쇄석체크댐은 수로 내 유속을 감소시켜 유출을 저감하고, 토사침식을 제어하며, 부유사를 침전케 하는 성능을 가진다. 하지만 강우유출수 내 직경 10~100 마이크론의 작은 미립자를 제거하기란 쉽지 않다. 본 연구에서 개발된 하이브리드형 탁수저감기법은 생분해성 체크댐과 합성 폴리머를 혼용한 시스템으로써, 응집제를 이용하여 유출수 내 미립자를 응집, 침전시키고, 체크댐을 이용해 반응 및 지체시간을 늘임으로써 미립자와 폴리머 사이의 반응을 유도하기 위한 것이다. 개발된 기술의 최적 사용을 위해 설치방법에 관련된 추가연구가 진행되었다. 생분해성 체크댐 설치 개수, 설치 간격, 녹화마대와의 혼용여부 등 추가 항목에 대한 실험결과 2중 체크댐보다는 1개 단독으로 사용되는 체크댐, 녹화마대와 혼용할 경우, 수로바닥과 생분해성 체크댐 바닥에 깔거나, 체크댐을 감싸는 형태로 설치하는 경우, 생분해성 체크댐의 설치 간격은 최소 6미터를 유지하는 경우 등에서 최적의 수질개선효과가 나타났다. 종합적인 연구결과 본 시스템은 탁도 뿐만 아니라 추가 5개 수질항목에 대해서 모두 90% 이상의 수질개선 효과를 나타내었으며, 기존의 최적관리기술의 보조적인 수단으로써 충분히 사용가치가 있음을 증명하였다. Check dams are small structures designed to slow the speed of concentrated stormwater flows, control erosion, and allow suspended sediment to settle out, but suspended solids, particles that typically ranging from 10 to 100 microns in diameters, are not easily removable. The hybrid turbidity reduction system consisting a biodegradable check dam (BCD) and synthetic polymer was developed in this study. Supplementary study was followed up to determine the installation method. Many relevant factors were brought up and they were a number of BCD, burlap mat, installation space, and so on. The findings of this study were : 1) single occupancy of BCD, 2) co-use with burlap mat, 3) spreading or wrapping a BCD with a burlap mat, 4) at least 6m spacing between BCDs, and so on. Water samples from laboratory and field were collected and analyzed for a total of 6 water quality items (BOD, COD, Turbidity, etc.). Overall evaluation of this study revealed that the hybrid turbidity reduction system not only reduced a level of turbidity in runoff waters but also improved water quality up to 90%. The hybrid turbidity reduction system clearly showed that it could contribute to best manage agricultural NPS pollution as a supplementary method.