http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
Je-Young Woo,Kwang-Mun Lee,Bong-Chul Jee,Cheol-Hwi Ryu,Cheol-Hun Yoon,Jang-Hoon Chung,Yong-Ryul Kim,Sang-Bong Moon,An-Soo Kang 한국공업화학회 2010 Journal of Industrial and Engineering Chemistry Vol.16 No.5
Membrane electrode assemblies (MEAs) of covalently cross-linked sulfonated poly(ether ether ketone)(CL-SPEEK)/heteropolyacids (HPAs) composite polymer with platinum-based alloys such as Pt–Ru–Co and Pt–Ru–Ni were prepared and their electrochemical properties for water electrolysis were investigated. The HPAs, which were used in the composite membranes, were tungstophosphoric acid (TPA) (the part of TPA data was permitted by the previous authors), molybdophosphoric acid (MoPA),and tungstosilicic acid (TSiA). The MEAs with Pt–Co, Pt–Ru–Co, and Pt–Ru–Ni in the anode catalyst layer were prepared by means of a non-equilibrium impregnation–reduction (I–R) method. The electrocatalytic properties of composite membranes, such as the cell voltage and coulombic charge in CV, were in the following order: CL-SPEEK/MoPA40 > CL-SPEEK/TPA30 > CL-SPEEK/TSiA40 (wt%). For the optimum cell applications of water electrolysis, the cell voltage of Pt/PEM/Pt–Ru–Co (Electrodeposited (Dep)-MoPA) MEA with a CL-SPEEK/MoPA40 membrane was 1.70 V at 80 8C and 1 A cm2, and this voltage carried a value lower than that of 1.81 V of Nafion 117. In addition, the observed activity of Pt–Ru–Co (75:12:13 by EDX) is a little higher than that of Pt–Ru–Ni (79:10:11 by EDX). The mean coulombic charge and activity enhancement of Pt–Ru–Co catalysts, with and without electrodeposition, showed the same CV profiles of the Pt–Ru–Co catalysts and were in the following order: Nafion 117 < CL-SPEEK/TSiA40 < CL-SPEEK/TPA30 < CL-SPEEK/MoPA40. The current density peak of electrodeposited electrodes was a little better than those of inactivated electrodes on the same membranes. The current peak by Pt–Ru–Co with CL-SPEEK/MoPA40 (Dep-MoPA) is more than about three times as high as those of Pt electrodes on the same membranes. 2010 The Korean Society of Industrial and Engineering Chemistry. Published by Elsevier B.V. All rights reserved.
Je-Ryung Lee,Tae-Jin Je,Sangwon Woo,Yeong-Eun Yoo,Jun-Ho Jeong,Eun-chae Jeon,Hwi Kim 한국광학회 2018 Current Optics and Photonics Vol.2 No.2
In this paper, mesoscale optical surface structures are found to possess both geometric and wave optics features. The study reveals that geometric optic analysis cannot correctly predict the experimental results of light transmission or reflection by mesoscale optical structures, and that, for reliable analyses, a hybrid approach incorporating both geometric and wave optic theories should be employed. By analyzing the transmission patterns generated by the mesoscale periodic pyramid prism plates, we show that the wave optic feature is mainly ascribed to the edge diffraction effect and we estimate the relative contributions of the wave optic diffraction effect and the geometric refraction effect to the total scattering field distribution with respect to the relative dimension of the structures.
이재령(Je-Ryung Lee),전은채(Eun-chae Jeon),제태진(Tae-Jin Je),우상원(SangWon Woo),최두선(Do-Sun Choi),유영은(Yeong-Eun Yoo),김휘(Hwi Kim) 한국기계가공학회 2014 한국기계가공학회지 Vol.13 No.4
A transparent poly methyl methacrylate (PMMA) optical micro-pyramid array-pattern is designed and fabricated using an injection modeling technique. The device’s optical characteristics are tested and analyzed theoretically. In the optical pattern generated using the fabricated PMMA pattern, the components, due to not only refraction but also diffraction, are observed simultaneously. Wave optic modeling and analysis reveals that the energy ratio between the diffraction and refraction in the optical pattern are dependent on the critical dimension of the optical pattern such that refraction and diffraction tend to be directly and inversely proportional to the pattern dimension, respectively.
Lee, Je-Ryung,Jeon, Eun-chae,Kim, Hwi,Woo, Sang-Won,Je, Tae-Jin,Yoo, Young-Eun,Lee, Eung-Sug Korean Society for Precision Engineering 2015 International Journal of Precision Engineering and Vol.16 No.7
The use of an optical plate to enhance light efficiency of LED systems was suggested. The optical plate technology indicates that polymeric optical plates having optical patterns on themselves are placed on LED systems. We designed and manufactured an optical plate that enhance light efficiency, and verified its optical characteristics in this study. The shape and the size of the spherical lens patterns were designed based on the lens formula including the refraction indices of air and PMMA, thickness of the optical component and the optical distance. To manufacture the optical plate having the designed spherical lens patterns, a metal mold was machined by ultra-fine punching machining technology. Using the ultra-fine punching machining system, spherical lens patterns with 0.45 mm in height, 1.15 mm in diameter were successfully machined on the top of a mold of 90 * 60 mm2 size. Using the machined mold and transparent PMMA, an optical plate with the spherical lens patterns was molded by injection molding technology. The optical plate was placed on the LED system, and the luminance was measured with and without the optical plate, and as a result the average and the maximum intensity increased by 1.4 times and 1.3 times respectively.
Schottky junction photodiode based on graphene—organic semiconductor heterostructure
최영진,Hwi Je Woo,Seongchan Kim,Jia Sun,Moon Sung Kang,Young Jae Song,Jeong Ho Cho 한국공업화학회 2020 Journal of Industrial and Engineering Chemistry Vol.89 No.-
The isolation of graphene on an insulating substrate has provided new opportunities for the fabrication ofelectronic devices with radically new geometries and structures. The use of single-layer graphene as anelectrode has enabled the development of novel electronic device architectures that exploit the uniqueatomically thin structure of the material, which also includes a low density of states at its chargeneutrality point. In this work, we present thefirst example of a vertical Schottky junction photodiodebased on the graphene—organic semiconductor–metal heterostructure. The n-type N,N0-dioctyl-3,4,9,10-perylenedicarboximide (PTCDI-C8) organic semiconductor was thermally deposited onto chemical vapordeposition (CVD)-grown single-layer graphene. The tunable Schottky injection barrier permitted tuningof the diode rectification ratio by more than two orders of magnitude upon application of gate biases,which increased the photocurrent but suppressed the dark current of the photodiodes. Tuning of thephotovoltaic properties of the devices was also confirmed, indicating that the device architecture basedon the work function tunability of graphene could provide a versatile strategy for enhancing theperformance of organic photodiodes.
Reconstruction of conductivity using the dual-loop method with one injection current in MREIT
Lee, Tae Hwi,Nam, Hyun Soo,Lee, Min Gi,Kim, Yong Jung,Woo, Eung Je,Kwon, Oh In Institute of Physics in association with the Ameri 2010 Physics in medicine & biology Vol.55 No.24
<P>Magnetic resonance electrical impedance tomography (MREIT) is to visualize the internal current density and conductivity of an electrically conductive object. Injecting current through surface electrodes, we measure one component of the induced internal magnetic flux density using an MRI scanner. In order to reconstruct the conductivity distribution inside the imaging object, most algorithms in MREIT have required multiple magnetic flux density data by injecting at least two independent currents. In this paper, we propose a direct method to reconstruct the internal isotropic conductivity with one component of magnetic flux density data by injecting one current into the imaging object through a single pair of surface electrodes. Firstly, the proposed method reconstructs a projected current density which is a uniquely determined current from the measured one-component magnetic flux density. Using a relation between voltage potential and current, based on Kirchhoff's voltage law, the proposed method is designed to use a combination of two loops around each pixel from which to derive an implicit matrix system for determination of the internal conductivity. Results from numerical simulations demonstrate that the proposed algorithm stably determines the conductivity distribution in an imaging slice. We compare the reconstructed internal conductivity distribution using the proposed method with that using a conventional method with agarose gel phantom experiments.</P>
Deep Outlier Detection on Raman Data
Joungbin An,Hwi Yoon,Whang Je Woo,Seung-min Chung,Won-Yong Shin,Hyungjun Kim 한국통신학회 2021 한국통신학회 학술대회논문집 Vol.2021 No.2
It is a crucial task to detect outlier strains formed in the MoS<sub>2</sub> film in improving its performance since those strains affect electronic properties such as the bandgap and electronic structure. We present a deep learning method in detecting outlier strains formed in the MoS2 film by using Raman spectroscopy data and convolutional autoencoder.
MREIT of Postmortem Swine Legs using Carbon-hydrogel Electrodes
Minhas, Atul S.,Jeong, Woo-Chul,Kim, Young-Tae,Kim, Hyung-Joong,Lee, Tae-Hwi,Woo, Eung-Je The Korean Society of Medical and Biological Engin 2008 의공학회지 Vol.29 No.6
Magnetic resonance electrical impedance tomography(MREIT) has been suggested to produce cross-sectional conductivity images of an electrically conducting object such as the human body. In most previous studies, recessed electrodes have been used to inject imaging currents into the object. An MRI scanner was used to capture induced magnetic flux density data inside the object and a conductivity image reconstruction algorithm was applied to the data. This paper reports the performance of a thin and flexible carbon-hydrogel electrode that replaces the bulky and rigid recessed electrode in previous studies. The new carbon-hydrogel electrode produces a negligible amount of artifacts in MR and conductivity images and significantly simplifies the experimental procedure. We can fabricate the electrode in different shapes and sizes. Adding a layer of conductive adhesive, we can easily attach the electrode on an irregular surface with an excellent contact. Using a pair of carbon-hydrogel electrodes with a large contact area, we may inject an imaging current with increased amplitude primarily due to a reduced average current density underneath the electrodes. Before we apply the new electrode to a human subject, we evaluated its performance by conducting MREIT imaging experiments of five swine legs. Reconstructed conductivity images of the swine legs show a good contrast among different muscles and bones. We suggest a future study of human experiments using the carbon-hydrogel electrode following the guideline proposed in this paper.
Development of GEBRET: a web-based analysis tool for retroelements in primate genomes
Hong-Seok Ha,Woo-Keun Chung,안궁,Jin-Han Bae,Sang-Je Park,Jae-Woo Moon,Kyu-Hwi Nam,Kyudong Han,조환규,김희수 한국유전학회 2011 Genes & Genomics Vol.33 No.6
Retroelements play important roles in primate evolution. Specifically, human endogenous retroviruses (HERVs) and Alu elements are primate-specific retroelements. In addition, SVA elements belong to the youngest family of hominid non-long terminal repeat (LTR) retrotransposons. Retroelements can affect adjacent gene expression, supplying cis-regulatory elements,splice sites, and poly-A signals. We developed a database,GEnome-wide Browser for RETroelement (GEBRET,http://neobio.cs.pusan.ac.kr/~gebre/), for comparing the distribution of primate-specific retroelements and adjacent genes. GEBRET database components include 47,381 HERVs,53,924 Alus and 4639 SVAs in five primate genomes of human,chimpanzee, orangutan, rhesus macaque, and marmoset. Host genes located upstream of a retroelement were also visualized and classified as five categories (0.0, 0.5, 1.0, 2.0,and 3.0Kb). Our results suggest that retroelements preferentially integrate into the distal promoter region relative to the core promoter region. GEBRET database is designed to investigate the distribution of retroelements (HERVs, Alus and SVAs) in the primate genomes that have been sequenced. Our software will be useful in the field to study the impact of retroelements on primate genome evolution.