Environmental risk assessment of neonicotinoids for Asian honey bee and simultaneous analysis of pesticide residues in apiculture samples

Yongho Shin,So-Hee Kim,Woo-Seok Ahn,Mun-Ju Jeong,Jeong-Han Kim 한국응용곤충학회 2022 한국응용곤충학회 학술대회논문집 Vol.2022 No.04

Design of a planar 3-DOF parallel micro—manipulator

Jeong Jae Lee,Yong Hwan Yoo,YongHo Jeon,Jaehwa Jeong,Moon G. Lee 대한기계학회 2013 대한기계학회 춘추학술대회 Vol.2013 No.5

데페이즈망 기법을 활용한 디자인 작품 사례 연구

정용호(Jeong, Yongho) 한국디자인지식학회 2015 디자인지식저널 Vol.33 No.-

벨기에의 초현실주의 작가 르네 마그리트(Rene Magritte)는 일상적인 사물을 예기치 않은 공간에 두거나 크기를 왜곡시켰다. 나아가 그는 사물에 대한 관습적인 인식을 논리적으로 뒤집어 자신만의 독특한 회화 세계를 구축하였다. 본 연구는 크게 세 개의 단락으로 구분되어 연구하였다. 첫 번째, 미술사학자 알렉산드리안(Sarane Alexandrian)의 데페이즈망(depaysement) 분류 방식을 통해 마그리트 작품들 속에서 공통적으로 나타난 다양한 데페이즈망을 연구한다. 데페이즈망을 활용한 사례 연구를 통해 방법론을 고찰한다. 사례 연구를 통하여 데페이즈망 기법이 다양한 디자인 분야에서 쓰이고 있음을 알 수 있었다. 마지막으로 데페이즈망 기법을 적용한 작품제작을 통하여 작품 아이디어를 위한 데페이즈망의 새로운 가능성을 실험하는 것이 목표이다. 그러나 상호작용성에 치중하여 작품의 주제를 표현하기 위한 데페이즈망 기법이 효과적으로 표현되지 못했던 문제점이 제기되었다. 본 논문은 다양한 데페이즈망 기법은 광고나 건축 분야 및 미디어 작품 제작에 창의적인 표현 방법으로써 활용될 수 있음을 제시한다. 앞으로 디자인 영역에서 창작을 위한 다양한 방법론으로서 활용 될 수 있는 데페이즈망 기법에 대한 연구가 더 필요하다. Belgian surrealist artist Rene Magritte put everyday objects in unexpected spaces or distort a size of everyday object. In addition, He who logically change the conventional perception of things was building his own unique world. This study was conducted in three major sectors. First, The purpose of this study is to investigate the various depaysement techniques commonly appeared in Magritte works through a classification of the art historian Alexandrian about depaysement. Then This study consider a methodology of depaysement through a case study in depaysement technique. This technique was found that being used in a variety of design fields through a case study. Finally, By making a work which is applied depaysement, This goal of study is to experiment new possibility of depaysement used in ideas on works. But Focusing only on interactivity, The problem of depaysement technique to express the theme of the work had not been raised effectively represented. This study suggests a variety of techniques of depaysement which can be used to method as a creative expression in advertising and architecture and media productions. In future, More studies is needed on new study about depayement that can be used as a methodology for the creation in the design fields.

A benchmark problem for the two- and three-dimensional Cahn–Hilliard equations

Jeong, Darae,Choi, Yongho,Kim, Junseok Elsevier 2018 Communications in nonlinear science & numerical si Vol.61 No.-

<P><B>Abstract</B></P> <P>This paper proposes a benchmark problem for the two- and three-dimensional Cahn–Hilliard (CH) equations, which describe the process of phase separation. The CH equation is highly nonlinear and an analytical solution does not exist except trivial solutions. Therefore, we have to approximate the CH equation numerically. To test the accuracy of a numerical scheme, we have to resort to convergence tests, which consist of consecutive relative errors or a very fine solution from the numerical scheme. For a fair convergence test, we provide benchmark problems which are of the shrinking annulus and spherical shell type. We show numerical results by using the explicit Euler’s scheme with a very fine time step size and also present a comparison test with Eyre’s convex splitting schemes.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Benchmark problems are provided for the Cahn–Hilliard equations. </LI> <LI> Accurate numerical solutions are generated using a very fine step size. </LI> <LI> The proposed method can be applied to most of the numerical schemes. </LI> </UL> </P>

Efficient 3D Volume Reconstruction from a Point Cloud Using a Phase-Field Method

Jeong, Darae,Li, Yibao,Lee, Heon Ju,Lee, Sang Min,Yang, Junxiang,Park, Seungwoo,Kim, Hyundong,Choi, Yongho,Kim, Junseok Hindawi Limited 2018 Mathematical problems in engineering Vol.2018 No.-

<P>We propose an explicit hybrid numerical method for the efficient 3D volume reconstruction from unorganized point clouds using a phase-field method. The proposed three-dimensional volume reconstruction algorithm is based on the 3D binary image segmentation method. First, we define a narrow band domain embedding the unorganized point cloud and an edge indicating function. Second, we define a good initial phase-field function which speeds up the computation significantly. Third, we use a recently developed explicit hybrid numerical method for solving the three-dimensional image segmentation model to obtain efficient volume reconstruction from point cloud data. In order to demonstrate the practical applicability of the proposed method, we perform various numerical experiments.</P>

Research of Self-disposal Evaluation for Domestic Hard-to-treat Radioactive Waste

Yongho Hong,Hyoungmin Park,Eunsuk Choi,Wonjin Jeong 한국방사성폐기물학회 2017 한국방사성폐기물학회 학술논문요약집 Vol.2017 No.05

山林小流域에서 산불이 溪流 水量 및 水質에 미치는 影響

程龍鎬,金景河,丁昌沂,全宰弘,劉在閏 한국임학회 2004 한국산림과학회지 Vol.93 No.7

본 연구는 2000년 4원 산불이 발생한 강원도 삼척시 근덕면 일대의 산불유역을 대상으로 산불에 따른 물환경의 변화를 밝힘으로써 산불발생지역의 물환경 보전대책 수립을 위한 자료를 제공하고자 수행하였다. 연구를 수행하기 위하여 산불발생유역과 산불비발생유역의 각 유역출구께서 2000년 5월부터 9월까지 4개월 동안 강수량, 유출량 등 수량일자와 생물화학적 산소요구랑(BOD), 화학적 산소요구량(COD), 전질소(TN), 총인(TP), 양이온(Na^+, Mg^(2+)) 및 음이은(Cl^-, NO₃^-), 부유물질량(SS) 9개 수질인사에 대하여 총 36차에 걸쳐 물 환경 변화를 모니터링하였다. 우출성분을 분리한 결과, 산불비발생유역은 직접유출이22%, 기저유출이 78%이었으나, 산불발생유역은 직접유출이 41%, 기저유출이 59%로 산불발생유역이 산불비발생유역에 비해 직접유출이 많이 발생하였다. 모든 수질인자들의 평균 농도 산불비발생유역에 비해 산불발생유역이 골아 산불로 인해 수질이 악화된 것으로 판단되며, 이중 전질소(TN), 총인(TP), NO₃^-, 부유출질량(SS)의 농도가 현저하게 증가하였다. 또한, 계류수질의 경시적 변화를 분석한 결과, 생물화학적 산소요구량(BOD)과 화학적 산요구량(COD)은 산불발생 후 4개월이 경과한 8월부터 두 지역간에 차이가 거의 없는 것으로 나타나 산불에 의해 교란되었던 계류수질이 산불발생 후 4개월이 경과한 시점에서 뚜렷하게 안정화되는 것으로 분석되었다. 따라서, 계류수질에 대한 산불피해의 영향은 초기 4개월 동안 가장 강하게 나타나며, 이후 시간이 경과함에 따라 대부분의 수질인자들이 안정되어 산불피해의 영향이 저감되는 것으로 나타났다. This study was conducted to investigate the effects of forest fire on the water quality and quantity. The burned watershed had been damaged by forest fire broken out in April, 2000. An unburned watershed was selected to compare with the burned watershed. Monitoring parameters were precipitation, water level, 130D, COD, TN, TP, Cl^-, NO₃^-, Na^+, Mg^(2+) and SS, and the monitoring was continued from June to September, 2000. Hydrograph separations in two watersheds during 2 months in 2000 resulted that the rates of direct runoff and base flow in the burned watershed were 41% and 59%, whereas those represented 22% and 78% in the unburned watershed. The periodic mean concentrations of each water quality parameters measured in the burned watershed were higher than those in the unburned watershed. Especially, there were big differences between the periodic mean concentrations of TN, TP, NO₃^- and SS under the burned and unburned watershed. Also, there were wide differences between monthly mean concentrations of each parameter under the burned and unburned watershed in June, 2000. However, those differences were smaller in a lapse of time. In particular, there weren't distinctive differences between monthly mean concentrations of each parameter under the burned watershed and those under the unburned watershed from August, 2000. Therefore, it was concluded that the effects of forest fire on the streamwater quality were decreased after four months forest fire broke out.

Fast MOG (Mixture of Gaussian) Algorithm based on Predicting Model Parameters

Yongho Kim,Soowoong Jeong,Jeongsu Oh,Sangkeun Lee 중앙대학교 영상콘텐츠융합연구소 2015 TechArt :Journal of Arts and Imaging Science Vol.2 No.1

Variable calculation at all pixels in a mixture of Gaussians (MOG) is a major obstacle for applications related to background removal. This paper presents a fast MOG algorithm based on partial parameter prediction. The proposed algorithm is applied to a limited number of pixels in order to reduce computational costs while maintaining conventional performance, and the parameter prediction is conducted using only the previous values and simple constant subtractions. Experiment results show that the predicted parameters almost match, in terms of pixel-to-pixel comparisons, to the exactly computed parameters in order to determine a proper model. In particular, the fast algorithm can save more than 37% of the model’s parameter computations while retaining 99.89% and 96.62% image and object-unit accuracies, respectively. Furthermore, it is verified that the pixels of the lost object do not affect the MOG algorithms. Therefore, we believe that it can be a useful tool for fast application development based on MOG algorithms.

NUMERICAL IMPLEMENTATION OF THE TWO-DIMENSIONAL INCOMPRESSIBLE NAVIER–STOKES EQUATION

YONGHO CHOI,DARAE JEONG,SEUNGGYU LEE,JUNSEOK KIM 한국산업응용수학회 2015 Journal of the Korean Society for Industrial and A Vol.19 No.2

In this paper, we briefly review and describe a projection algorithm for numerically computing the two-dimensional time-dependent incompressible Navier?Stokes equation. The projection method, which was originally introduced by Alexandre Chorin [A.J. Chorin, Numerical solution of the Navier?Stokes equations, Math. Comput., 22 (1968), pp. 745?762], is an effective numerical method for solving time-dependent incompressible fluid flow problems. The key advantage of the projection method is that we do not compute the momentum and the continuity equations at the same time, which is computationally difficult and costly. In the projection method, we compute an intermediate velocity vector field that is then projected onto divergence-free fields to recover the divergence-free velocity. Numerical solutions for flows inside a driven cavity are presented. We also provide the source code for the programs so that interested readers can modify the programs and adapt them for their own purposes.

Modeling and simulation of the hexagonal pattern formation of honeycombs by the immersed boundary method

Jeong, Darae,Choi, Yongho,Kim, Junseok Elsevier 2018 Communications in nonlinear science & numerical si Vol.62 No.-

<P><B>Abstract</B></P> <P>We present a simple mathematical model and numerical simulations of the hexagonal pattern formation of a honeycomb using the immersed boundary method. In our model, we assume that the cells have a circular shape at their inception and that there is a force acting upon the entire circumference of the cell. The net force from the individual cells is a key factor in their transformation from a circular shape to a rounded hexagonal shape. Numerical experiments using the proposed mathematical model confirm the hexagonal patterns observed in honeybee colonies.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We present a simple mathematical model of the hexagonal pattern formation. </LI> <LI> To validate the proposed model, we compared simulated and experimental results. </LI> <LI> The proposed model captures the main transformation mechanism of honeycomb. </LI> </UL> </P>