딥러닝을 이용한 한반도 주변 파랑예측

문종윤(Jongyoon Mun),조완희(Wanhee Cho),성보람(Boram Seong),한수만(Sooman Han),최진휴(Jinhyu Choi) 한국해양환경·에너지학회 2021 한국해양환경·에너지학회 학술대회논문집 Vol.2021 No.5

본 연구는 한반도 주변의 기상정보로 파랑을 예측하고 CCTV 영상에서 월파를 감지하는 기술을 개발하였다. 성능의 우수성이 널리 알려진 인공신경망(Artificial Neural Network, ANN)의 한 종류인 합성곱신경망(Convolutional Neural Network, CNN)을 사용하여 파랑예측과 월파감지 모델을 구축하였다. 파랑예측에 사용된 CNN모델은 U-net을 기반으로 구축하였으며 월파감지에 사용된 CNN모델은 객체 검출 모델을 사용하였다. 파랑예측 모델의 입력 자료는 일본 기상청(Japan Meteorological Agency, JMA)의 대기 예측정보인 MSM(Meso Scale Model)을 사용하였다. 합성곱신경망 파랑예측 모델의 학습데이터는 ADSWAN(ADCIRC + SWAN) 파랑모의 결과의 위도 30˚ ∼42.75˚, 경도 122.5˚∼135.25˚영역을 사용하였으며 격자 간격은 0.05˚로 설정하였다. 파랑 예측 모델의 정확도 향상을 위해 기존 U-net 구조의 인코더와 디코더 레이어의 깊이를 7층으로 확장하여 사용하였다. 상관성 분석 결과, 파고와 주기는 각각 풍속과 파고에 상관성이 높게 나타나 바람장 정보로부터 유의파고를 예측하고 예측된 유의파고로부터 주기를 예측하는 두 단계의 예측 모델을 구성하였다. 예측 결과에서 ADSWAN 파랑모의와의 상관성은 0.93, 관측치와의 상관성은 0.83으로 분석되었고 1시간 예측에 약 0.024초가 소요되었다. 월파감지 모델의 학습데이터는 삼척과 주문진의 CCTV 1년 1개월 분량의 영상(2018.10.01. ∼ 2019.10.31.)에서 월파가 발생한 프레임을 수동으로 추출하여 약 2만장의 데이터를 구축하였다. 월파의 기준은 탐지된 파도 영역이 난간을 넘는 것으로 설정하였으며, 난간을 넘지 않는 파도를 구분하기 위해 배경과 파도를 분리하고 난간 구역과 비교하여 여과하는 알고리즘을 구축하였다. 또한, 해수면과 분리된 파도 영역을 비교하여 실제 처오름높이를 산정하였으며, 월파감지의 정확도 분석 결과 mAP₅₀은 0.60, 속도는 80.5fps로 나타났다. In this study, we developed a technology to predict wave using atmospheric modeling data around the Korean Peninsula and to detect wave overtopping using CCTV images. For the development, we adopted Convolutional Neural Network(CNN), a kind of Artificial Neural Network(ANN) known for its high performance. Wave prediction model is based on U-net, whereas overtopping detection model makes use of object detection models. Input data for the wave prediction model is MSM (Mesoscale Model) atmospheric forecasting data from the Japan Meteorological Agency(JMA). The training data for wave prediction model is ADSWAN(ADCIRC+SWAN) wave simulation results, whose spatial extension is 122.50°E 135.25°E, 30.00°N∼42.75°N with resolution of 0.05°. In order to improve the accuracy of wave prediction model, we extend the depth of the encoder and decoder layers from the U-net structure to the seventh layers. Correlation analysis shows that wave heights are highly correlated with wind speeds while wave periods are with wave heights. Thus, we constructed a two-step model that predicts wave heights from the former and wave periods from the latter. In our prediction results, correlations with ADSWAN wave simulation results and observation were found to be 0.93 and 0.83 respectively. The 1-hour prediction took about 0.024 seconds. The training data for overtopping detection model is around 20,000 frames manually extracted from one year-long CCTV video images (2018.10.01. ∼ 2019.10.31.) from Samcheok and Jumunjin. We defined wave over the fence as a overtopping event, and developed a filtering algorithm to separate the background from the wave by comparing regions. Furthermore, we estimated wave run-up height from the separated wave regions and preformed the accuracy analysis, mAP₅₀ being 0.60 and the processing speed being 80.5fps.

SWAT을 이용한 산림 성장과 수종 분포변화에 따른 유역수문 영향평가

한대영 ( Daeyoung Han ),이지완 ( Jiwan Lee ),김원진 ( Wonjin Kim ),박종윤 ( Jongyoon Park ),김주연 ( Juyeon Kim ),김성준 ( Seongjoon Kim ) 한국농공학회 2021 한국농공학회 학술대회초록집 Vol.2021 No.-

A Nanofilter Array Chip for Fast Gel-Free Biomolecule Separation.

Fu, Jianping,Mao, Pan,Han, Jongyoon American Institute of Physics 2005 APPLIED PHYSICS LETTERS Vol.87 No.26

<P>We report here a microfabricated nanofilter array chip that can size-fractionate SDS-protein complexes and small DNA molecules based on the Ogston sieving mechanism. Nanofilter arrays with a gap size of 40-180nm were fabricated and characterized. Complete separation of SDS-protein complexes and small DNA molecules were achieved in several minutes with a separation length of 5mm. The fabrication strategy for the nanofilter array chip allows further increasing of the nanofilter density and decreasing of the nanofilter gap size, leading, in principle, to even faster separation.</P>

Stabilization of Ion Concentration Polarization Using a Heterogeneous Nanoporous Junction

Kim, Pilnam,Kim, Sung Jae,Han, Jongyoon,Suh, Kahp Y. American Chemical Society 2010 NANO LETTERS Vol.10 No.1

<P>We demonstrate a recycled ion-flux through heterogeneous nanoporous junctions, which induce stable ion concentration polarization with an electric field. The nanoporous junctions are based on integration of ionic hydrogels whose surfaces are negatively or positively charged for cationic or anionic selectivity, respectively. Such heterogeneous junctions can be matched up in a way to achieve continuous ion-flux operation for stable concentration gradient or ionic conductance. Furthermore, the combined junctions can be used to accumulate ions on a specific region of the device.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/nalefd/2010/nalefd.2010.10.issue-1/nl9023319/production/images/medium/nl-2009-023319_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl9023319'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl9023319'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl9023319'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl9023319'>ACS Electronic Supporting Info</A></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nl9023319'>ACS Electronic Supporting Info</A></P>

Tunable Ionic Transport for a Triangular Nanochannel in a Polymeric Nanofluidic System

Kim, Bumjoo,Heo, Joonseong,Kwon, Hyukjin J.,Cho, Seong J.,Han, Jongyoon,Kim, Sung Jae,Lim, Geunbae American Chemical Society 2013 ACS NANO Vol.7 No.1

<P>Recently, tremendous engineering applications utilizing new physics of nanoscale electrokinetics have been reported and their basic fundamentals are actively researched. In this work, we first report a simple and economic but reliable nanochannel fabrication technique, leading to a heterogeneously charged triangular nanochannel. The nanochannel utilized the elasticity of PDMS when it bonded with a micrometer-scale structure on a substrate. Second, we successfully demonstrated novel ionic transportations by tweaking the micrometer structures: (1) the transition of nonlinear ionic conductance depending on the nanochannel properties and (2) the ionic field-effect transistor. Nanochannel conductance has two distinguishable nonlinear regimes called the “surface-charge-governed” and the “geometry-governed” regime and its only individual overlooks were frequently reported. However, the transition between two regimes by adjusting nanochannel properties has not been reported due to the difficulty of functional nanochannel fabrication. In addition, a gate voltage was comfortably applied to the triangular nanochannel so that the field-effect ion transportation was reliably achieved. Therefore, presenting triangular nanochannels have critical advantages over its heterogeneous and tunable surface properties and thus, could be an effective means as an active fundamental to control and manipulate the ion-electromigration through a nanofluidic system.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/ancac3/2013/ancac3.2013.7.issue-1/nn3050424/production/images/medium/nn-2012-050424_0006.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/nn3050424'>ACS Electronic Supporting Info</A></P>

Non-Lithographic Wrinkle Nanochannels for Protein Preconcentration

Chung, Seok,Lee, Jeong Hoon,Moon, Myoung-Woon,Han, Jongyoon,Kamm, Roger D. WILEY-VCH Verlag 2008 Advanced Materials Vol.20 No.16

<B>Graphic Abstract</B> <P>A simple, non-lithographic method to create a nanofluidic channel array that exploits wrinkles is demonstrated. The dimension and position of the wrinkles can be precisely controlled, producing wrinkle nanochannels (WNCs) that range in size from several tens of nanometers to micrometers. The usefulness of the WNCs is demonstrated by preconcentration of a protein, which is shown to vary linearly. Preconcentration levels of more than 100 can be achieved within 10 minutes. <img src='wiley_img/09359648-2008-20-16-ADMA200701715-content.gif' alt='wiley_img/09359648-2008-20-16-ADMA200701715-content'> </P>

Nanofluidic preconcentration device in a straight microchannel using ion concentration polarization.

Ko, Sung Hee,Song, Yong-Ak,Kim, Sung Jae,Kim, Myungji,Han, Jongyoon,Kang, Kwan Hyoung Royal Society of Chemistry 2012 Lab on a chip Vol.12 No.21

<P>In this paper, we introduce a simple, straight microchannel design for a nanofluidic protein concentration device. Compared with concentration devices previously developed, the anode channel and cathode channel in this new concentration scheme are both integrated into a straight microchannel, with one inlet and one outlet. Most of the functions of a conventional two-channel concentration device can be achieved by this concentration device, and the efficiency of sample accumulation can be controlled by the dimension of the Nafion membrane. Also, the operating mechanism of this device was tested on various material combinations such as PDMS (polydimethyl-siloxane) channel-glass substrate and silicon channel-PDMS substrate. Using a combined PDMS-silicon device which was sealed reversibly without plasma bonding, surface based immunoassay for concentrator-enhanced detection of clinically relevant samples such as C-reactive protein (CRP) was demonstrated. As a result, it was possible to enhance the detection sensitivity of the immunoassay by more than 500 folds compared to the immunoassay without preconcentration process.</P>

High-Throughput and Massively-Parallel Concentrator for Multiplexed Immnunoassays Applications

Sung Hee Ko,Sung Jae Kim,Lih Feng Cheow,Leon D. Li,Jongyoon Han,Kwan Hyoung Kang 대한기계학회 2011 대한기계학회 춘추학술대회 Vol.2011 No.4

Fabrication of nanofluidic channels with directed wrinkle/buckling patterns

Seok Chung(정석),Myoung-Woon Moon(문명운),Jeong Hoon Lee(이정훈),Jongyoon Han(한종윤),Roger D. Kamm 대한전기학회 2009 대한전기학회 학술대회 논문집 Vol.2009 No.7

Interest has grown recently in the concept of "unconventional nanofabrication", the creation of nanoscale features by methods that avoid the technical hurdles and high cost of nano-lithographic processes. One of the challenges has been to reliably and inexpensively produce channels of nanometer dimension, as small as 60 ㎚, in the materials commonly used for soft lithography. In this manuscript, we present new approaches based on simple concepts of wrinkle and buckling patterns.

이온농도분극에 의한 와류현상에서 관찰된 유동전단응력-이동장벽 효과

곽노균(Rhokyun Kwak),Van Sang Pham,강지윤,한종윤(Jongyoon Han) 대한기계학회 2015 대한기계학회 춘추학술대회 Vol.2015 No.11

Rotating shear flow is a common tool to suppress turbulence and control transport in plasma physics. Despite the desires to apply this phenomenon to other fields, it has rarely been observed in non-ionized fluids. Here, we visualize this effect on a generic neutral-fluid situation in electro-membrane systems: electroconvective vortex (EC) under Hagen-Poiseuille (HP) flow, which initiated by ion concentration polarization (ICP) on ion exchange membranes. This is the first demonstration of “flow-shear-induced transport barrier” in electrochemical systems, which was found only in magnetized flow previously. Combining scaling analysis and experiment, we capture the effect by pinpointing the threshold for shear suppression. Selected by balancing velocity fluctuation (with EC vortices) and flow shear (with noslip walls), the threshold is scaled as the dimensionless EC height dec/w=0.618. Stable EC occurs under the threshold, while chaotic EC occurs over the threshold by velocity fluctuation overwhelming flow shear. The threshold we identify here has wide applications to prevent chaotic flows in various electro-membrane systems.