• 한국식물생명공학회:학술대회논문집
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• 한국식물생명공학회 2005년도 추계학술대회 및 한일 식물생명공학 심포지엄
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• pp.81-83
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• 2005

The Plant Signaling Network Research Center (SigNet) is a government-funded (by Korea's Ministry of Science and Technology (MOST)/ Korea Science and Engineering Foundation (KOSEF)) research center established at the School of Life Sciences and Biotechnology of Korea University in 2003. The SigNet conducts plant biological studies, especially in the field of developmental and defense biology. The research purpose of SigNet is dissection and analysis of plant development and defense signaling network through multiscientific approaches. Knowledge acquired from SigNet research scientists will provide new integrated view of understanding and potential application of plant development and defense mechanism. The other important mission of the SigNet is nurturing Center of Excellence for future outstanding research scientists of Korea. The SigNet will continue to expend every effort to achieve the goals for the future. Through passionate research endeavor of each laboratory and partnerships within inside and outside laboratories, we will continue to develop world-leading plant research group and to educate new generations of innovative researchers. As the SigNet looks toward the future, the SigNet will try to achieve its mission of research, education and service to the community. And the defense response research of our lab will be presented at later part.

• Applied Science and Convergence Technology
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• 제26권5호
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• pp.143-147
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• 2017

Structural studies on the addition characteristics of Nb ions to $BaTiO_3$ solid solutions were performed by XRD and SEM/EDS technique. The X-ray diffraction peaks of the (111), (200) and (002) planes of Nb-doped $BaTiO_3$ solid solutions with different mole% of Nb were analyzed. We also investigated the relationship between the dielectric and structural properties of Nb-doped $BaTiO_3$. The transition temperatures of $BaTiO_3$ solid solution doped with 0.5mole%Nb and 1.0 mole%Nb were ${\sim}116^{\circ}C$ and ${\sim}87^{\circ}C$, respectively, which were found to be shifted to very low temperature from the transition temperature of pure $BaTiO_3$ (about $125^{\circ}C$). As a result of analysis of 1/K versus T and ln[$(1/K)-(1/K_m)$ versus ($T-T_m$)] of the two compositions used in this experiment, the diffusivity slightly differs from that of pure $BaTiO_3$ at temperatures above Curie temperature. And this characteristic was analyzed by applying the modified Curie-Weiss law.

• Applied Science and Convergence Technology
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• 제24권6호
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• pp.224-227
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• 2015

Ferroelectric $Pb_2(Sc,Nb)O_6$ were prepared under two different sintering conditions using the oxide mixing method and the electrical properties were measured. The sintering conditions were $1350^{\circ}C$ for 25 minutes and $1400^{\circ}C$ for 20 minutes. EDX spectroscopy and XRD were used to determine the crystalline characteristic of the $Pb_2(Sc,Nb)O_6$ compositions Pyrochlore phase showed about 2% in all $Pb_2(Sc,Nb)O_6$ specimens. It expands the growth of crystals in samples sintered at $1400^{\circ}C$ than $1350^{\circ}C$, but all samples were the optimal crystallization. The temperature and frequency dependence of the complex dielectric constant and admittance were measured to analyze the electrical properties. The high dielectric constant of the specimens reflects the good stoichiometry and crystallization. The maximum value of the dielectric constant in the two specimens treated with sintering at $1350^{\circ}C$ and $1400^{\circ}C$ were more than 27,000, and the dielectric loss at room temperature is smaller than 0.05. The maximum dielectric constant decreased with increasing frequency, the transition temperature also increased in $Pb_2(Sc,Nb)O_6$ compositions. The admittance and susceptance values reach a peak at all temperatures, and the magnitude of the peak increases with increasing measuring temperature. Strong frequency dependent of maximum admittance, susceptance, dielectric constant and dielectric loss were observed.

• 공업화학
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• 제26권3호
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• pp.287-293
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• 2015

본 논문은 층상구조에 기반을 둔 리튬 2차 전지용 양극 활물질 관련 기술에 대한 특허정량분석에 관한 것으로, 우리나라 356건, 미국 1,628건, 일본 2,915건, 유럽 439건, PCT (WO) 611건 등 등록/공개된 5,000여 건의 특허를 분석하였다. 본 특허정량분석을 통해 1991년도부터 2013년까지의 리튬 코발트 개량기술, 대체 기술의 경향을 분석하였으며, 우리나라, 미국, 일본 유럽 등 주요국별로 리튬이차전지 기술의 특허 점유율을 구하였다. 그중 차세대 리튬이차전지 기술로 부상하고 있는 구조 혼합 기술 관련 특허는 2000년에 다수 출원되기 시작하여 2005년도에는 SANYO (34.5% 점유), SONY (17.5% 점유), LG (7% 점유) 및 SAMSUNG (5.5% 점유)을 필두로 많은 특허가 출원되었다. 마지막으로 성분계별 공정 분포도를 버블차트로 작성하여 분야별 연구 집중도를 확인하였다.

• 공업화학
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• 제26권3호
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• pp.294-305
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• 2015

본 특허정성분석은 "층상구조 기반의 리튬이차전지용 양극 활물질"의 우리나라, 미국, 일본, 유럽, PCT (WO)의 유효특허 1,294건을 분석한 것으로, 특허가 갖는 기술 중요도 부분과 특허 중요도 부분으로 나누어 Table 1과 같은 기준으로 평가하였고, 이를 토대로 104건의 주요특허와 20건의 핵심특허를 선정하였다. 그리고 선정된 주요특허와 핵심특허를 시계열적 기술 흐름도로 작성하여 각 기술 분류별로 특허 출원 시점과 발전 과정, 핵심특허의 위치를 확인하였다. 마지막으로 특허 분석 내용을 토대로 향후 기술개발을 위하여 현재 출원 등록된 기술들과의 차별화 방안 및 회피전략을 제시하였다.

• 한국정보통신학회논문지
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• 제24권8호
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• pp.1095-1101
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• 2020

선박이나 항공기의 안정성 유지를 위하여 컨테이너나 화물의 무게 균형을 유지하도록 적재해야 한다. 컨테이너의 적재 알고리즘은 NP 문제로 알려져 있으며 몇 가지 휴리스틱 방법이 연구되었다. 선박이나 비행기에 보관할 컨테이너는 부피와 무게가 균일하다는 특징이 있는데 이를 이용하면 좀 더 쉬운 적재 방법을 찾을 수 있다. 본 논문에서는 물체의 부피와 무게가 균일할 때 무게 균형을 위한 알고리즘을 제안한다. 적재 공간은 m * n 메쉬의 특수한 구조라고 가정한다 (이때, m과 n은 모두 홀수이다). 이 경우, 본 논문에서는 Greedy 알고리즘을 제안하였고 물체의 개수가 몇 개이든 언제나 무게 균형을 유지하는 적재 장소를 찾을 수 있다는 점에서 그 알고리즘이 최적임을 증명하였다. 제안된 알고리즘은 적재 알고리즘 및 부하 균형 문제와 같은 여러 공학 문제에서 활용될 수 있다.

• 한국재료학회지
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• 제32권5호
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• pp.243-248
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• 2022

This study demonstrates a different approach method to fabricate antimony selenide (Sb₂Se₃) thin-films for the solar cell applications. As-deposited Sb₂Se₃ thin-films are fabricated via electrodeposition route and, subsequently, annealed in the temperature range of 230 ~ 310℃. Cyclic voltammetry is performed to investigate the electrochemical behavior of the Sb and Se ions. The deposition potential of the Sb₂Se₃ thin films is determined to be -0.6 V vs. Ag/AgCl (in 1 M KCl), where the stoichiometric composition of Sb₂Se₃ appeared. It is found that the crystal orientations of Sb₂Se₃ thin-films are largely dependent on the annealing temperature. At an annealing temperature of 250 ℃, the Sb₂Se₃ thin-film grew most along the c-axis [(211) and/or (221)] direction, which resulted in the smooth movement of carriers, thereby increasing the carrier collection probability. Therefore, the solar cell using Sb₂Se₃ thin-film annealed at 250 ℃ exhibited significant enhancement in J_SC of 10.03 mA/cm² and a highest conversion efficiency of 0.821 % because of the preferred orientation of the Sb₂Se₃ thin film.

• Steel and Composite Structures
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• 제49권4호
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• pp.381-392
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• 2023

This study experimentally investigates the flexural behavior of steel-UHPC composite slabs composed of an innovative negative Poisson's ratio (NPR) steel plate and Ultra High Performance Concrete (UHPC) slab connected via demountable high-strength bolt shear connectors. Eight demountable composite slab specimens were fabricated and tested under traditional four-point bending method. The effects of loading histories (positive and negative bending moment), types of steel plate (NPR steel plate and Q355 steel plate) and spacings of high-strength bolts (150 mm, 200 mm and 250 mm) on the flexural behavior of demountable composite slab, including failure mode, load-deflection curve, interface relative slip, crack width and sectional strain distribution, were evaluated. The results revealed that under positive bending moment, the failure mode of composite slabs employing NPR steel plate was distinct from that with Q355 steel plate, which exhibited that part of high-strength bolts was cut off, part of pre-embedded padded extension nuts was pulled out, and UHPC collapsed due to instantaneous instability and etc. Besides, under the same spacing of high-strength bolts, NPR steel plate availably delayed and restrained the relative slip between steel plate and UHPC plate, thus significantly enhanced the cooperative deformation capacity, flexural stiffness and load capacity for composite slabs further. While under negative bending moment, NPR steel plate effectively improved the flexural capacity and deformation characteristics of composite slabs, but it has no obvious effect on the initial flexural stiffness of composite slabs. Meanwhile, the excellent crack-width control ability for UHPC endowed composite members with better durability. Furthermore, according to the sectional strain distribution analysis, due to the negative Poisson's ratio effect and high yield strength of NPR steel plate, the tensile strain between NPR steel plate and UHPC layer held strain compatibility during the whole loading process, and the magnitude of upward movement for sectional plastic neutral axis could be ignored with the increase of positive bending moment.

• 대한인간공학회지
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• 제32권1호
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• pp.9-16
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• 2013

Objective: The aim of this study is to investigate a trend of human error types observed in a series of verification and validation experiments for an Advanced Control Room(ACR) equipped with Lager Display Panel(LDP), Work Station Flat Panel Display(WS FPD), list type Alarm System(AS), Soft Control(SC) and Computerized Procedure System(CPS). Background: Operator behaviors in a fully computerized control room are quite different from those in a traditional hard-wired control room. Operators in an ACR all together monitor plant status and variables through their own interface system such as LDP and WS FPD, are notified of abnormal plant status through their own list type AS, control the plant through their own SC, and follow the structured procedure through their own CPS whereas operators in a traditional control room only separately do their duty directed by their supervisor. Especially the secondary task such as manipulating the user interface of ACR can be an extra burden to all the operators including the supervisor. Method: The Reason's human error classification method was applied to operators' behavioral data collected from a series of verification and validation experiments where operators showed their plant operational behaviors under a couple of harsh scenarios using the ACR simulator. Results: As operators accustomed to the new ACR system, knowledge or rule based mistakes appearing frequently in the early series of experiments decreased drastically in the latest stage of the series. Slip and lapse types of errors were observed throughout the series of experiments. Conclusion: Education and training can be one of the most important factors for the operators accustomed to the traditional control room to be adapted to the new system and to run the ACR successfully. Application: The results of this study implied that knowledge or rule based mistakes can be reduced by training and education but that lapse type errors might be reduced only through innovative improvement in human-system interface design or teamwork culture design including a new leadership style suitable for ACR.

• 한국자동차공학회논문집
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• 제20권4호
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• pp.142-149
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• 2012

The reduction characteristics of $NO_2$ to NO are experimentally studied over a platinum-based catalyst, especially at lower temperatures below about $200^{\circ}C$. In the present work, two types of steady-state experiments, engine bench and synthetic gas bench tests, are carried out in sequence. Steady-state engine bench tests with the DOC mounted on a light duty 4-cylinder 2.0 liter turbocharged diesel engine are performed and prove that CO plays a major role in $NO_2$ abatement at temperatures below the light-off temperature of CO oxidation, about $200^{\circ}C$. Synthetic gas bench tests are then performed using synthetic gas mixtures with CO, $C_3H_6$, NO, $NO_2$, $O_2$, $H_2O$ and $N_2$ in the $140{\sim}450^{\circ}C$ T-range and show that both CO and $C_3H_6$ are capable of reducing $NO_2$. It is noted that the reaction rate of $NO_2$ with $C_3H_6$ is much higher than that with CO. At temperatures below about $200^{\circ}C$, the reduction of $NO_2$ to NO is promoted with increasing CO concentration and $NO_2$/$NO_X$ ratio and with decreasing $O_2$ concentration, as well as with the presence of $H_2O$.