http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Electro-Mechanically Responsive Ionoelastomer Heterojunctions
HyeongJun Kim(김형준) 한국고분자학회 2021 한국고분자학회 학술대회 연구논문 초록집 Vol.46 No.1
Soft solids capable of conducting ions offer promise for the design of entirely new classes of highly deformable and bio-inspired devices. Here, we introduce ‘ionoelastomers’—soft polymer networks capable of selectively conducting either anions or cations—to demonstrate liquid-free, elastic, and stretchable ionic diodes and transistors that operate entirely via non-Faradaic processes. We show that the junction of two oppositely charged ionoelastomers yields an ‘ionic double layer’, analogous to the depletion layer in a semiconducting p-n junction. Furthermore, soft and stretchable ionoelastomer junctions provide fundamentally new functionalities including: 1) low voltage reversible electro-adhesion and 2) electro-mechanical transduction, i.e., the conversion of mechanical deformation into electrical signals.
An Empirical Study on Credit Card Loan Delinquency in Korea
( Hyeongjun Kim ),( Hoon Cho ) 한국금융공학회 2015 한국금융공학회 학술발표회 Vol.2015 No.1
This study investigates credit card loan delinquency in Korea. We define three states-no delinquency, delinquency, and serious delinquency-and test the transition probabilities between them using quarterly observed account-level data. Our findings have several economic implications. First, factors that affect delinquency risk can differ from those that affect the transition to serious delinquency. Second, the recent increase in the number of seriously delinquent accounts can be attributed to changes in the distribution of borrower ages. Third, macroeconomic conditions-especially differences in growth between the gross domestic product and consumption-have led to the recent increase in delinquent accounts.
EFFICIENT AND ACCURATE COMPUTATIONS OF ALL-SPEED CRYOGENIC TWO-PHASE FLOWS AROUND TURBOPUMP INDUCER
Hyeongjun Kim,Daeho Min,Donghwan Kim,Chongam Kim 한국산업응용수학회 2013 한국산업응용수학회 학술대회 논문집 Vol.8 No.1
The present paper deals with a numerical method for all-speed cryogenic cavitating flows in turbopump inducer. Recently, we have developed an accurate and efficient baseline numerical scheme for the computations of all-speed two-phase flows. By extending such progress, we conduct some modification of preconditioning technique and propose an accurate and efficient numerical method to deal with the computations of cryogenic two-phase flows. To verify pressure and temperature depression effect in cryogenic cavitation, we carry out numerical simulations of cryogenic cavitation flows around hydrofoil. Compared with Hord’s experimental data, computed results are turned out to be quite satisfactory. Finally, numerical simulations of KARI turbopump inducer are carried out under various flow conditions with water and cryogenic fluids, and we examine the differences in inducer flow physics depending on the working fluids.
COMPUTATIONS OF ALL-SPEED CRYOGENIC CAVITATING FLOWS IN TURBOPUMP INDUCER
Hyeongjun Kim,Daeho Min,Donghwan Kim,Chongam Kim 한국산업응용수학회 2012 한국산업응용수학회 학술대회 논문집 Vol.7 No.2
The present paper deals with a numerical method for all-speed cryogenic cavitating flows in turbopump inducer. Recently, we have developed an accurate and efficient baseline numerical scheme for the computations of all-speed two-phase flows. By extending such progress, we conduct some modification of preconditioning technique and propose an accurate and efficient numerical method to deal with the computations of cryogenic two-phase flows. To verify pressure and temperature depression effect in cryogenic cavitation, we carry out numerical simulations of cryogenic cavitation flows around hydrofoil. Compared with Hord’s experimental data, computed results are turned out to be quite satisfactory. Finally, numerical simulations of KARI turbopump inducer are carried out under various flow conditions with water and cryogenic fluids, and we examine the differences in inducer flow physics depending on the working fluids.
RGB-D Visual SLAM Algorithm Using Scene Flow and Conditional Random Field in Dynamic Environments
Hyeongjun. Jeon,Changwan Han,Donggil You,Junghyun. Oh 제어로봇시스템학회 2022 제어로봇시스템학회 국제학술대회 논문집 Vol.2022 No.11
For many years, SLAM algorithms for dynamic environments have been studied. Most methods use semantic segmentation models and it was applied to SLAM by erasing a predetermined type of dynamic object. However, these methods ignored static elements that could exist within dynamic objects in the SLAM process. In this paper, we propose an RGB-D Visual SLAM method using Scene flow and Conditional Random Field in dynamic environments. The proposed method uses static elements inside dynamic objects for Visual Odometry. First, we use dense optical flow to obtain pixel matching between frames and RANSAC algorithms to obtain relative pose. Then, we use depth maps between scenes and matching information to obtain Scene Flow. We calculate dynamic likelihood from this scene flow and create dynamic mask and modify it to be resistant to noise using the Conditional Random Field. We conducted experiments in TUM dataset containing dynamic objects. In experiment, this algorithm has been able to achieve similar or better results than the previeous method using semantic segmentation.