Co이온의 첨가량에 따른 InGaZn_(1-xCo_x O_4) 분말의 물성 연구

황은상,박수환,박인석,박성균,배종성 한국물리학회 2011 새물리 Vol.61 No.10

InGaZn_(1-xCo_x O_4)(x= 0.00, 0.01, 0.05, 0.10) powders were synthesized using solid state reaction methods to examine the Co concentration dependence of the structural, spectroscopic and magnetic properties. From the X-ray diffraction analysis, we did not observe a structural variation as the Co concentration was increased. Futhermore, X-ray photoelectron spectroscopy revealed that all the core-level spectra remained the same within our detection limit. However, samples with Co concentrations less than 0.10 exhibited a ferromagnetic behavior. 고상 반응법을 이용하여 InGaZn_(1-xCo_x O_4) 물질에 Co이온을 첨가한InGaZn_(1-xCo_x O_4)(x = 0, 0.01, 0.05, 0.10) 분말을 제작하여분말의 구조적, 화학적 및 자기적 특성을 연구하였다. X-선 회절을측정한 결과 Co이온의 첨가에 따른InGaZn_(1-xCo_x O_4)물질이구조적 변화를 일으키지 않는다는 것을 확인하였다. 또한, 광전자분광법을 통해서도 Co 이온의 첨가에 의한 다른 원소들의 화학적결합에너지 변화는 일어나지 않았다. 하지만, 미량의 Co이온 (x =0.01)을 첨가한 시료에 대해서 상온에서 강자성체 특성을 얻을 수있었다. Co이온의 첨가량이 증가함에 따라 상대적인 자기 모멘트 값의감소가 나타나고, Co가 1 \% 첨가된 시편에 대해서는 상자성 특성이보이는 것을 알 수 있었다.

펄스 레이저 증착 방법으로 성장한 InGaZnO4 박막의 물리적 특성 연구

황은상,서유성,박수환,배종성,안재석,황정식,박성균 한국진공학회 2011 한국진공학회 학술발표회초록집 Vol.40 No.0

폴리우레탄을 이용한 Thiobacillus sp. IW의 고정화

황은상,이광우,박돈희 전남대학교 촉매연구소 2001 觸媒硏究 論文集 Vol.22 No.-

The immobilization of Thiobacillus sp. IW, the hydrogen sulfide removing bacterium, was studied by using the adsorption and physical capture methods. In the case of immobilization by the adsorption, the type, size, and amount of polyurethane foam were affected by the cell immobilization capacity of supporter. Among supporters, MC-70 was better immobilizing material. The optimum size and amount of polyurethane foam were 5∼8mm and 8g/L, respectively. In the case of immobilization by the physical capture, polyurethane foam could be prepared with the same ratio of modified MDI prepolymer, polyol, and medium with better condition. The optimum size and amount of polyurethane foam were 6∼7mm and 8g/L, respectively. Considering the cell immobilization capacity, the immobilization by physical capture was more effective than the immobilization by adsorption. The immobilization intensity by adsorption was 85% after shaking for 24hrs, whereas the immobilization by physical capture was 92% under the same condit

발달 장애 아동 발음학습을 위한 가상상담 구축 방법론 적용에 대한 연구

황은상 ( Eunsang Hwang ),함창수 ( Changsu Ham ),박준호 ( Joonho Park ) 한국정보처리학회 2020 한국정보처리학회 학술대회논문집 Vol.27 No.2

발달 장애 아동은 사회생활을 위한 언어 훈련을 진행하고 있다. 언어 훈련은 상황에 맞는 질문에 대한 답변과 행동을 위한 교육이다. 본 연구는 발달 장애 아동의 발음학습을 위해 가상상담 시스템 구축방법론을 적용한다. 발달 장애 아동 교육을 위해서는 각 상황에 맞는 질문과 답변 등을 구성하여 교육한다. 가상상담 구축도 시나리오 형태로 시스템을 구축한다. 본 연구는 가상상담 시스템 구축 방법론을 활용하여 발달 장애 아동 발음학습을 구현하는 방법을 제시하도록 하겠다.

PPP 성능 향상을 위한 Byte Stuffing에 관한 연구

황은상(Eun-Sang Hwang),안형승(Hyung-Seung An),박영근(Young-Keun Park) 한국통신학회 2003 한국통신학회 학술대회 및 강연회 Vol.2003 No.4

대학 및 지역 공공 도서관 열람실의 실내공기질 특성

申殷相,黃相容,金鍾五,洪宗淳 동남보건대학 2002 論文集-東南保健大學 Vol.20 No.2

The purpose of this study is to investigate the concentration patterns of air pollution in public library and university libraries, and to evaluate indoor air quality in each library. The measurements and questionnaire survey of indoor air environment were performed to investigate the indoor air pollution level of the reading rooms. As a result, the profiles of air temperature, air humidity, air-flow, WBGT, the concentration of carbon dioxide(CO₂), carbon monoxide(CO), ozone(O₃), total suspended particles(TSP) and other conditions for physical comfort for the users were analyzed and presented. Mean temperature of this investigation was higher than optimum temperature of indoor air quality and relative humidity was similar to indoor air standard. Mean concentration of CO and TSP showed 0.9±0.2 ppm, 65±27 ㎍/㎥ which was below in the standard of air quality. However, CO₂ concentration appeared 1.366±277 ppm that was about 1.3 times higher than the standard of indoor air quality except one university. Correlation coefficients between users and air pollutants showed significant difference for CO₂. no significant difference for CO. The results of questionnaires research for indoor air qualities had no significant correlations. This reason showed that there was no concern about indoor air quality relatively to thermal conditions for the users.

Li+이온을 첨가한 RnVO₄:Eu³+(Rn=Y, Gd, La)형광체의 형광특성

한옥식,황은상,박혁규,박성균,배종성,김종필,김양수,채종석,박효열 한국물리학회 2009 New Physics: Sae Mulli Vol.59 No.3

Rn1-x-yVO4:Eu3+x, Li+y 분말 형광체를 고상반응법으로 합성하고, 모체물질, Li+ 첨가 여부에 따른 결정구조와 형광특성을 조사하였다. X선 회절 실험과 X선광전자분광기를 이용한 측정을 통해 Li+와 Eu3+ 이온이 모체물질 내에 잘 치환이 되었고, YVO4와 GdVO4는 tetragonal, LaVO4는 monoclinic 구조를 가지는 것을 알 수 있었다. Photoluminescence 측정을 통해 모체구조가 tetragonal일 경우가 monoclinic인 경우에 비해 형광 특성이 우수한 것을 확인하였고, Li+ 이온 첨가로 인해 형광 강도가 증가하는 것을 알 수 있었다. SEM 이미지 측정 결과 Li+ 첨가로 인해 입자의 크기가 커지고 형태가 구형으로 변하는 것을 확인 하였고, YVO4와 GdVO4의 경우는 15 mol %, LaVO4의 경우는 10 mol %의 Li+ 이온을 첨가 하였을 때 가장 좋은 형광 특성을 가지는 것을 확인 하였고, 그 이상을 첨가할 경우 농도소광 현상이 발생하는 것을 볼 수 있었다. Rn1-x-yVO4:Eu3+x, Li+y (Rn = Y, Gd, La) phosphors synthesized using solid-state reaction methods to study their structural and optical properties. From the X-ray diffraction study, we found that the RnVO4:Eu3+,Li^ systems maintained their original crystal structure (the known crystal structure without Eu and Li doping) and had no secondary phases due to the additional doping. From the room-temperature photoluminescence (PL) study, we found a red emission peak at 619 nm due to the transition of 5D0\rightarrow7F2 for the Eu doped samples, indicating Eu ions were well substituted into the host materials. Furthermore, we observed when we used YVO4 and GdVO4 as host materials, the PL characteristics were better than they were when we used a LaVO4 host material, suggesting that the structural difference between tetragonal (YVO4, GdVO4) and monoclinic (LaVO4) may influence the optical properties. We also found that the PL intensity increased after doping with Li+ ions, and we found the optimal Li+ ion concentration for better PL characteristics for a given Eu3+ concentration. In the case of YVO4 and GdVO4 and LaVO4, the optimal Li+ ion concentration was 15 mol %, and 10 mol %, respectively.

CNN 기반의 웹툰 유사도 분석 모델 연구

김선교,황은상,김종권,정성태 한국지능정보시스템학회 2019 한국지능정보시스템학회 학술대회논문집 Vol.2019 No.10

Antidepressant-like Effects of p-Coumaric Acid on LPS-induced Depressive and Inflammatory Changes in Rats

이석,김현범,황은상,김은석,김성수,전태동,송민철,이지승,정민찬,맹성호,박지호 한국뇌신경과학회 2018 Experimental Neurobiology Vol.27 No.3

Depression causes mental and physical changes which affect quality of life. It is estimated to become the second most prevalent disease, but despite its commonness, the pathophysiology of depression remains unclear and medicine is not sufficiently protective. pCoumaric acid (p-CA) is a dietary phenolic acid which has been proven to have antifungal, anti-HIV, anti-melanogenic, antioxidant and anti-inflammatory effects. Considering these effects, we investigated whether p-CA can prevent depressive symptoms by reducing inflammatory cytokines in animals injected with lipopolysaccharide (LPS). Changes in despair-related behaviors, inflammatory cytokines, neurotrophic factors and synaptic activity were measured. In these animals, p-CA improved despair-related behavioral symptoms induced by LPS in the forced swim test (FST), tail suspension test (TST) and sucrose splash test (SST). p-CA also prevented the increase of inflammatory cytokines in the hippocampus such as cycloxigenase-2 and tumor necrosis factor-α due to LPS. Similarly, it prevented the reduction of brain-derived neurotrophic factor (BDNF) by LPS. Electrophysiologically, p-CA blocked the reduction of long-term depression in LPS-treated organotypic tissue slices. In conclusion, p-CA prevented LPS-induced depressive symptoms in animals, as determined by behavioral, biochemical and electrophysiological measures. These findings suggest the potential use of p-CA as a preventive and therapeutic medicine for depression.

적층형 압전 액츄에이터를 이용한 L1-B4형 선형 초음파 리니어 모터의 타원변위궤적

이갑수,류주현,황은상,박덕원,Lee, Kab-Soo,Yoo, Ju-Hyun,Hwang, Eun-Sang,Park, Durk-Won 한국전기전자재료학회 2008 전기전자재료학회논문지 Vol.21 No.1

In this study, multilayer structured ultrasonic linear motor was simulated using Atila for investigating its optimum driving conditions. The ultrasonic linear motors mainly consist of an ultrasonic vibrator to generate elliptical displacement. The ultrasonic linear motor simulated in this paper was the use of the 1st longitudinal(Ll) and 4th bending vibrations (B4). Whit the increase of the number of piezoelectric actuator layers, displacement of node was increased. Maximum total displacement of node was about $3,91{\mu}m$ at the 13 layered ultrasonic motor under 5 V.