가습 조건에 따른 고분자전해질 연료전지 성능평가 연구

김현일(Hyun-il Kim),김영두(Youngdoo Kim),남진현(Jin Hyun Nam),신동훈(Donghoon Shin),정태용(Tae-Yong Chung),김영규(Young-Gyu Kim) 한국가스학회 2008 한국가스학회 학술대회논문집 Vol.2008 No.11

3축 로봇 개념을 이용한 시뮬레이션 기반 모바일 위성안테나 설계

김현일(Hyun-il Kim),김성수(Sung-Soo Kim),원문철(Moon-cheol Won),허재영(Jae-young Huh) 대한기계학회 2005 대한기계학회 춘추학술대회 Vol.2005 No.5

A mobile satellite antenna has been virtually designed using 3-axes robot design concept. Mobile satellite antennas must have abilities to target a satellite and at the same time to stabilize the antenna dish in order to maintain its orientation toward the satellite. To achieve such design requirements, three axes robot design concept has been employed. A 3-D CAD model has been creel ted to virtually realize the design concept. In order to insure the created CAD model. kinematic analyses have been carried out for collision detection of the parts. Inverse dynamic analyses have been also carried out to compute required torques for motor selection using multibody dynamic analysis program ADAMS. Since mobile satellite antennas experience base motions, a relevant control system should control the three antenna axis to maintain the dish orientation to point the satellites accurately. A PIDA control algorithm are designed and Implemented into the virtual multi body model to control the yaw. level (roll). and cross-level (pitch) angle of a mobile satellite antenna. ADAMS and Matlab co-simulation scheme is employed in order to examine whether proposed PIDA control algorithm provides effective characteristics comparing with PID control.

키 발급 서버를 이용한 암호데이터 중복제거 기술

김현일(Hyun-il Kim),박철희(Cheolhee Park),홍도원(Dowon Hong),서창호(Changho Seo) 한국정보과학회 2016 정보과학회논문지 Vol.43 No.2

데이터 중복제거 기술은 클라우드 스토리지를 절약하기 위해 반드시 필요한 기술이다. 평문데이터 중복제거 기술은 기본적으로 데이터의 기밀성을 유지하지 못하므로 암호데이터 중복제거 기술이 필요함은 당연하다. 본 논문은 키 발급 서버의 도움을 받는 암호데이터 중복제거 기술에 대해 연구하며 그 중 Bellare 등이 제안한 기법에 대한 분석 및 구현을 수행하였으며 키 발급 서버를 이용한 기술에 대한 효율성 측정을 위해 상용 클라우드 서비스 상에 Bellare 등이 제안한 기법과 평문 및 ConvergentEncryption에 대한 성능 측정을 수행하였다. 또한 상용 클라우드 서비스인 Dropbox 및 공개 클라우드 서비스 중 하나인 Openstack의 Swift상에 구현 및 효율성 측정을 수행함으로써 키 발급 서버를 이용한 암호데이터 중복제거 기술에 대한 범용성을 검증하였다. Data deduplication is an important technique for cloud storage savings. These techniques are especially important for encrypted data because data deduplication over plaintext is basically vulnerable for data confidentiality. We examined encrypted data deduplication with the aid of a key issuing server and compared Convergent Encryption with a technique created by M.Bellare et al. In addition, we implemented this technique over not only Dropbox but also an open cloud storage service, Openstack Swift. We measured the performance for this technique over Dropbox and Openstack Swift. According to our results, we verified that the encrypted data deduplication technique with the aid of a key issuing server is a feasible and versatile method.

태양광발전 도시 프로젝트의 개발현황과 발전방향 고찰

김현일(Kim Hyun-Il),서승직(Suh Seung-Jik),박경은(Park Kyung-Eun),강기환(Kang Gi-Hwan),유권종(Yu Gwon-Jong) 한국태양에너지학회 2008 한국태양에너지학회 논문집 Vol.28 No.6

Buildings are responsible for approximately 50% of current carbon dioxide emissions. Energy planning at a town and city scale needs a strategic approach, supported by strong planning policies. The purpose of this study was to investigate the urban scale grid-connected photovoltaic(PV) system for urban residential and commercial sector applications. The integration of PV technology into roof of houses is an approach that is being championed in Germany, Japan and United states etc. In the Korea, PV roofing systems already are given the large number of houses which are projected to be built by 2012. However unlike germany and Japan, urban scale grid-connected PV system is not yet installed. The solar city which is installed building-integrated photovoltaic system is available to use of renewable energy sources such as solar to meet demand, instead of fossil fuels, with the goal of realizing an ecologically oriented energy supply.

The Usage of Miniature Pig in the Large Size Experimental Animals

Hyun Il Kim(김현일) 한국실험동물학회 2021 한국실험동물학회 학술발표대회 논문집 Vol.2021 No.1

벼와 피 간 Fentrazamide의 선택성에 끼치는 항산화효소 활성의 영향

김현일(Hyun-Il Kim),임성진(Sung-Jin Lim),전재철(Jae-Chul Chun) 한국잡초학회 2009 한국잡초학회 별책(학술대회 초록집) Vol.29 No.2

2018 Korean Society of Hypertension guidelines for the management of hypertension: part I-epidemiology of hypertension

김현창,Sang-Hyun Ihm,김근호,Ju Han Kim,Kwang-Il Kim,Hae-Young Lee,이장훈,Jong-Moo Park,박성하,편욱범,신진호,채성철 대한고혈압학회 2019 Clinical Hypertension Vol.25 No.4

The Korean Society of Hypertension guideline defines hypertension as systolic blood pressure ≥ 140 mmHg or diastolic blood pressure ≥ 90 mmHg, where the effectiveness of pharmacological treatment has been established. It is confirmed that higher blood pressure levels are associated with increased risk of cardiovascular disease and mortality also in the Korean population. About one third of Korean adults aged 30 years or older are estimated to have hypertension, and the prevalence of hypertension gradually increases as the age increases. The awareness, treatment, and control rates of hypertension are generally improving in Korea, but more efforts are required to increase awareness and treatment among younger patients with hypertension and to improve lifestyle modification compliance at all ages. More studies are required to determine the magnitude and impact of white coat hypertension and masked hypertension in the Korean population.

관측 강우와 심층신경망의 적용을 통한 도시홍수 분석

김현일(Kim, Hyun Il),이재영(Lee, Jae Young),한건연(Han, Kun Yeun),조재웅(Cho, Jae Woong) 한국방재학회 2020 한국방재학회논문집 Vol.20 No.1

도시유역의 홍수 발생은 주로 저지대의 유수 집중과 배수관거의 만관에 의해 발생하는데, 이는 높은 강우강도와 집중적인양상을 가지는 강우 사상과 함께 나타난다. 도시유역에 대한 유출량 사전 분석을 위해서는 SWMM이 이용될 수 있지만, 대상 유역이 넓고 배수시스템이 복잡한 경우 1차원 도시유출해석에 적지않은 시간이 발생할 수 있다. 또한, 특정 도시 유역에대하여 많지 않은 침수 사례와 침수 유발 관측강우의 부족은 홍수 대비에 대한 기초자료를 제공하는데 어려움이 있다. 홍수를일으킬 위험 강우 발생 시 긴급하게 도시 유출량을 예측하기 위해서, 본 연구에서는 6시간 지속시간을 가지는 전국단위관측 강우사상을 반영하여 심층신경망 모형을 구축하였다. 하나의 강우사상에서 10개의 통계적 특성을 입력 자료로서 고려하였으며, 예측하고자 하는 목표값은 SWMM을 통한 10분 단위 총 누가 월류량으로 하였다. SWMM모의 결과의 적절성을 검증하기위해 2차원 수리해석 모형과 침수흔적도를 연계한 검증을 실시하였다. 대상지역에 대한 SWMM의 모의 시간은 14분이 소요되었으며, 본 연구에서 제시된 심층신경망과 관측 강우 자료 기반 모형은 2~3초 내외에서 수행되었다. 예측은 강남(400) AWS에서2011년 7월 27일에 관측된 강우사상에 대한 총 누가 월류량을 대상으로 하여 모형의 실용성을 검증하였다. Urban flooding primarily occurs due to flash floods in low-lying regions or insufficient capacity of drainage systems. Urban inundation has become more dangerous to residents because of an increase in impermeable areas, uncertainties in urban sewage planning, and the accumulation of sedimentation in drainage pipes. As an urban watershed with a drainage system and an urbanized river is complicated, a specific time interval is required for the preparation and processing of urban runoff analysis. To allow for rapid simulations of urban runoff estimation during heavy rainfall, a deep neural network model that imitates the conditions of a 6-h duration rainfall was developed in this study. Ten different statistical aspects for each rainfall event were considered as input data, and the total accumulated overflow from a manhole was calculated at intervals of 10 min using storm water management model (SWMM). To verify the accuracy of the results from SWMM, the results obtained from a two-dimensional hydraulic model and an inundation trace map were compared. The computational times for the deep neural network and rainfall data-based models proposed in this study were estimated to be within 1 s, whereas the simulation using SWMM required 14 min. The proposed deep learning model was tested using the total accumulated overflow for the rainfall event observed at Gangnam (400) automatic weather station on July 27, 2011. The simulated results agreed with the observed results in terms of the total accumulated discharge.

반응표면분석법을 통한 Arthrobacter sp.의 amylase 생산 최적화

김현도 ( Hyun Do Kim ),임영금 ( Young Kum Im ),최종일 ( Jong Il Choi ),한세종 ( Se Jong Han ) 한국화학공학회 2016 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.54 No.1

본 연구에서는 극지 연구소로부터 분양 받은 Arthrobacter sp. PAMC 27388 균주에서 생산되는 아밀라아제(amylase)를 물리적 요인(physical factor)들의 변화를 통하여 생산배지 최적화를 수행하였다. 한천 배지 상에서 lugol solution을 이용한 클린환의 확인을 통하여 아밀라아제가 생산됨을 확인하였으며, 16S rDNA를 이용하여 동정한 결과 Arthrobacter sp. 임을 확인할 수 있었다. 최적화 이전의 아밀라아제 생산량은 1.66 mU/L로 확인되었다. 최적화 결과, 2.49 mL의 접종부피, pH 6.85, 42.87 mL의 배지 부피의 조건에서 가장 많은 양의 아밀라아제가 생산될 것으로 예상되었으며, 생산량은 2.84 mU/L로 예상되었다. 확인 실험을 통하여 최적화 이전과 비교하여 생산량이 약 150% 증가한 2.50 mU/L의 아밀라아제가 생산됨을 확인할 수 있었다. In this study, the physical factors for amylase production by Arthrobacter sp. were optimized using response surface methodology(RSM). Antarctic microorganism Arthrobacter sp. PAMC 27388 was obtained from the Polar and Alpine Microbial Collection(PAMC) at the Korea Polar Research Institute. This microorganism was confirmed for the excretion of amylase with Lugol`s solution. The amylase activity was after flask culture was as low as 1.66 mU/L before optimization. The physical factors including the inoculum volume, the initial culture pH, and the medium volume were chosen to be optimized for the enhanced amylase production. The calculated results using RSM indicate that the optimal physical factors were 2.49 mL inoculum volume, 6.85 pH and 42.87 mL medium volume with a predicted amylase production of 2.84 mU/L. The experimentally obtained amylase activity was 2.50 mU/L, which was a 150% increase compared to the level before optimization.

마이크로 버블 발생을 위한 노즐의 수치적 연구

김현일(Kim Hyun-il),황재순(Hwang Jaesoon),이상민(Lee Sang Min),신명선(Shin Myung Sun),이종호(Lee Jong Ho) (사)한국CDE학회 2012 한국 CAD/CAM 학회 학술발표회 논문집 Vol.2012 No.2

Recently, with the growth of living standards and income, the interest to the environment pollution is increased. According to the reinforcement of a water pollution regulation, a study for an efficiency improvement of sewage disposal carried out. There are many ways to efficiency improvement of sewage disposal. One of them way is to increase the dissolved oxygen content of water in water treatment tank. In this paper, we suggest a nozzle which can generate micro bubbles and increase the dissolved oxygen content of water. The micro bubbles through the flow of spiral and crash is generated in nozzle. This results of analysis show bad result that is large size of bubble by flow of crash because of limited velocity to inlet condition. The bubble size of 20~50 ㎛ has captured about 78% of the air to the nozzle using the flow of spiral in control volume. We can most likely increase efficiency improvement of sewage disposal by this study.