• 제목/요약/키워드: 박정현

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Astronomy experiments using digital instruments (디지털 장비를 이용한 천문 실험)

  • Lee, Sang Hyun;Lee, Kyung Hoon;Lee, Enjung;Park, Joo Hyun;Jang, Kyu Bin;Lee, Dongho;Jo, Hyungyu;Lee, MinWook;Kim, Ga Hyung;Ku, Minjun;Seol, Jinwoo;Kim, Dong Ju;Kin, KangJin;Park, Gyutae;Kim, Do-Hoon;Kim, Do Yun;Lee, Sumin;Moon, SeongKeong;Shin, LaEl;Choi, Joonyoung;Ahn, Jaehyung;Choi, Wonseok;Kim, ChiYoung;Park, Jeong Hyeon;Jo, Se Hyeun;Shin, Kwan Hun
    • The Bulletin of The Korean Astronomical Society
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    • v.41 no.1
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    • pp.63.4-64
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    • 2016
  • 본 발표에서는 DSLR 카메라와 CCD를 이용하여 과학고등학교의 R&E교육과정에서 수행한 몇 가지 실험과 그 결과를 소개한다. DSLR 카메라와 SQM을 이용한 밤하늘 특성 분석, CCD를 이용한 고유운동 측정, DSLR을 이용한 산개성단의 측광, CCD를 이용한 산개성단의 측광과 이를 통한 산개성단의 질량분리와 역학적 진화에 대한 연구이다. 실험은 부산일과학고, 울산과학고, 부산과학고에서 수행되었으며, 모든 실험의 결과는 학생들이 직접 관측한 결과를 바탕으로 이루어졌다. 본 실험의 방법과 과정은 일선 학교에서 응용하여 활용될 수 있으며, 실험의 결과는 향후 유사한 실험 교육을 수행할 때 기초 자료로 활용되어 질 수 있다.

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Effects of Hijikia fusiforme Extracts on Lipid Metabolism and Liver Antioxidative Enzyme Activities in Triton-Induced Hyperlipidemic Rats (톳(Hijikia fusiforme) 추출물이 고지혈증 횐쥐의 지질대사 및 간 효소활성에 미치는 영향)

  • 정복미;안창범;강성조;박정현;정덕화
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.30 no.6
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    • pp.1184-1189
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    • 2001
  • This study was conducted to investigate the effect of Hijikia fusiforme extracts on serum lipid and liver antioxidative enzyme activities in triton-induced hyperlipidemic rats. Sprague-Dawley male rats divided into 7 groups : We injected saline to a normal group (N), saline and tween 80 to control groups (CS, CT) and tot extracts to experimental groups (CSA, CTEtOH, CTE, CTH) for 7 days and then injected triton at the last day. Serum and liver free cholesterol contents were significantly lower in hexane-treated group (CTH) than control group (CT) whereas serum HDL-cholesterol content was higher in aqueous extract group (CSA) than control group (CS). Total cholesterol and phospholipid contents in serum and liver were lower in aqueous extract group (CSA) than control group (CS). Serum and liver triglyceride contents were significantly lower in ethanol (CTEtOH) and hexane treated group (CTH) than control group (CT). Thiobarbituric acid reactive substances of liver were lower in tot extract groups (CSA, CTEtOH, CTE, CTH) than control groups (CS, CT). Superoxide dismutase activities in liver were significantly lower in aqueous extracts group (CSA) and hexane treated group (CTH) than control groups (CS, CT). Liver catalase activity was the lowest in ethylacetate extract group. These results showed that some Hijikia fusiforme extracts have reduction effect of lipid and antioxidative effect in triton-induced hyperlipidemic rats.

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Oxidative Dehydrogenation of n-Butenes over BiFe0.65MoP0.1 Oxide Catalysts Prepared with Various Synthesis Method (다양한 합성 방법으로 제조된 BiFe0.65MoP0.1 산화물 촉매 상에서 n-부텐의 산화탈수소화 반응)

  • Park, Jung-Hyun;Shin, Chae-Ho
    • Korean Chemical Engineering Research
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    • v.53 no.3
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    • pp.391-396
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    • 2015
  • To investigate the effect of the catalyst synthesis method on the oxidative dehydrogenation (ODH) of nbutenes, $BiFe_{0.65}MoP_{0.1}$ oxide catalysts were prepared with various synthesis methods such as co-precipitation, citric acid method, hydrothermal method, and surfactant templated method. The catalysts were characterized by X-ray Diffraction (XRD), $N_2$ sorption, and $NH_3/1$-butene-temperature programmed desorption ($NH_3/1$-butene-TPD) to correlate with catalytic activity in ODH reaction. Among the catalysts studied here, $BiFe_{0.65}MoP_{0.1}$ oxide catalyst prepared with co-precipitation method marked the highest activity showing 1-butene conversion, 79.5%, butadiene selectivity, 85.1% and yield, 67.7% after reaction for 14 h. From the result of $NH_3$-TPD, the catalytic activity is closely related to the acidity of the $BiFe_{0.65}MoP_{0.1}$-x oxide catalyst and acidity of the $BiFe_{0.65}MoP_{0.1}$ oxde catalyst prepared with co-precipitation method was higher than that of other catalysts. In addition, combined with the 1-butene TPD, the higher catalytic activity is closely related to the amount of weakly adsorbed intermediate (< $200^{\circ}C$) and the desorbing temperature of strongly adsorbed intermediates (> $200^{\circ}C$).

Low Temperature CO Oxidation over CuO Catalyst Supported on Al-Ce Oxide Support (Al-Ce 산화물에 담지된 CuO 촉매상에서 저온 CO산화반응)

  • Park, Jung-Hyun;Yun, Hyun Ki;Shin, Chae-Ho
    • Korean Chemical Engineering Research
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    • v.55 no.2
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    • pp.156-162
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    • 2017
  • CuO(x)/0.3Al-0.7Ce catalysts with different CuO loadings (x = 2~20 wt%) were prepared by impregnation method and investigated the effects of CuO loadings on the low temperature CO oxidation. Of the used catalysts, the CuO(10)/0.3Al-0.7Ce catalyst showed the highest catalytic performance in the absence or presence of water vapor. In the presence of water vapor, the catalytic performance was drastically decreased, with a temperature of 50% CO conversion ($T_{50%}$) shifted to higher temperature by $50^{\circ}C$ compared to the those in dry conditions because of the competitive adsorption of water vapor on the active sites. The copper metal surface area calculated from $N_2O$-titration analysis and the oxygen capacity from CO-pulse experiments were increased with the CuO loadings and showed a maximum at 10 wt%CuO/0.3Al-0.7Ce catalyst. These trends are in good agreement with the tendency of $T_{50%}$ of the catalysts. From these characteristic aspects, it could be deduced that the catalytic performance was closely related to the oxygen capacity and the copper metallic surface area.

Analysis of Ground Watertable Fluctuation at the Sandy Barrier Island on Jinu-do in Nakdong River Estuary (낙동강 하구역 진우도 자연해빈의 지하수위 변동해석)

  • Park, Jung-Hyun;Yoon, Han-Sam;Lee, In-Cheol
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.20 no.4
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    • pp.382-388
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    • 2014
  • This study selected five observational stations in the normal direction of Jinu-do(island) shoreline and observed water temperature, electrical conductivity and pressure from March, 2012 to January, 2013(about 11 months) and attempted to see the variation characteristics of ground watertable. This study wants to know : 1) External environment force factors(tide, climate, wave etc.) affecting ground watertable variation through time series and correlation analysis. 2) Spatial variations of ground watertable and electrical conductivity change by storm event. First, we found that the station at the intertidal zone was strongly affected by wave and tide level and the stations at sand dune and vegetation zone was affected by precipitation and tide level through time series data and correlation analysis. Second, during the storm event, we found that ground watertable and electrical conductivity are stabilized at the start line of sand dune and vegetation zone and transition zone between freshwater layer and seawater layer exists in the experiment area and is about 50~70 m from coastline of the south side of Jinu-do(island).

Properties of AlN epilayer grown on 6H-SiC substrate by mixed-source HVPE method (6H-SiC 기판 위에 혼합소스 HVPE 방법으로 성장된 AlN 에피층 특성)

  • Park, Jung Hyun;Kim, Kyoung Hwa;Jeon, Injun;Ahn, Hyung Soo;Yang, Min;Yi, Sam Nyung;Cho, Chae Ryong;Kim, Suck-Whan
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.30 no.3
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    • pp.96-102
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    • 2020
  • In this paper, AlN epilayers on 6H-SiC (0001) substrate are grown by mixed source hydride vapor phase epitaxy (MS-HVPE). AlN epilayer of 0.5 ㎛ thickness was obtained with a growth rate of 5 nm per hour. The surface of AlN epilayer grown on 6H-SiC (0001) substrate was investigated by field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS). Dislocation density was considered through HR-XRD and related calculations. A fine crystalline AlN epilayer with screw dislocation density of 1.4 × 109 cm-2 and edge dislocation density of 3.8 × 109 cm-2 was confirmed. The AlN epilayer on 6H-SiC (0001) substrate grown by using the mixed source HVPE method could be applied to power devices.

Effects of Slurry Composting and Biofiltration Liquid Fertilizer on Growth Characteristic of Poplar Clones in a Reclaimed Land Mounding Soil (간척지 성토지 식재 포플러의 SCB액비 처리에 따른 클론별 생장특성)

  • Park, Jung-Hyun;Yeo, Jin-Kie;Koo, Yeong-Bon;Lee, Won-Woo;Kim, Hyun-Chul;Park, Chi-Ho
    • Korean Journal of Soil Science and Fertilizer
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    • v.41 no.5
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    • pp.318-323
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    • 2008
  • We studied on the effects of slurry composting and biofiltration liquid fertilizer (SCBLF) on growth of two-year-old poplar clones planted in a reclaimed land mounding soil. The soil on the experimental site had lower concentrations of both exchangeable cations and salinity than before reclamation. However, the content of organic matter was low compared with the most soils. We applied SCBLF to the poplars six times and 5 L in each time for 80 days. Ten clones of six poplar species or hybrids were tested in this study: Populus alba ${\times}$ P. glandulosa(Clivus, 72-30, 72-31, Bongwha1), P. deltoides ${\times}$ P. nigra(Dorskamp), P. deltoides(Lux) ${\times}$ P. deltoides(Harvard)(97-19), P. euramericana(Eco28, I-476), P. nigra ${\times}$ P. maximowiczii(62-2) and P. Koreana ${\times}$ P. nigra var. italica(Suwon). Growth performance varied more among clones than among species. Average height growth of treated plots was 18% greater than control, and clones Clivus, 97-19, Eco28 and Dorskamp were more vigorous than other clones. Diameter at breast height in treated plots was 41% greater than control, and 97-19, Dorskamp, Eco28 and Clivus were the four best clones in this respect. Mean leaf area of treated trees was 26% greater for control trees. Chlorophyll content was similar between treated and controlled trees. Total nitrogen values in leaves were much higher in treated trees 18%. SCBLF treatment on poplars planted in reclaimed land helped tree growth.

A Study on the Accuracy Improvement of Control Point Surveying of Photograph Using Digital Camera (디지털 카메라를 이용한 사진기준점측량의 정확도 향상에 관한 연구)

  • Kim, Kye-Dong;Park, Joung-Hyun;Lee, Young-Wook
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.2
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    • pp.203-211
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    • 2009
  • With supply of the domestic digital camera, the relative importance of the digital camera is coming to be high gradually on aerial photogrammetry, the image of digital camera is more applied in image map or digital topographic map production. But, there are cases that do not have position information or attitude information of each photograph in digital camera results. Therefore, we wish to present additional method to get more accurate photograph control point result. In this study, One is called A method, which is the case of entering positioning information of principal point from topographic map as default values that are need to extract tie point automatically using by 56 pieces of photography that are photographed by DMC to the extent to 5 courses and 35 GCP points. The other is called B-method, which is the case of entering exterior orientation parameters that are processed by block adjustment for A-method using by 4 control points in method-1 as default values. We have analyzed about results per control points arrangement for two cases using MATCH-AT that is photograph control point measurement S/W of Germany INPHO company. As a result of analysis, accuracy of B-method was better than that of A-method, and we could get more accurate results if block adjustments are executed including self calibration. Also, it is more effective in expense side that using self calibration for photograph survey in B-method because can reduce GCP numbers.

Accuracy Comparison as World Geodetic Datum Transformation of 1/1000 Digital Map (1/1,000 수치지형도의 세계측지계 변환에 따른 정확도 비교)

  • Yun, Seok-Jin;Park, Joung-Hyun;Park, Joon-Kyu
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.27 no.2
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    • pp.169-175
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    • 2009
  • According as standard of measurement is changed to world geodetic system by surveying law revision, we need to transform previous 1/1,000 digital maps as a standards of world geodetic system. And, we should acquire standard strategy to minimize confusion and error by conversion of geodetic surveying standards. Thus, conversion of digital maps must be transformed efficiently and consistently according to notice of relevant standard. As common point, we have used 1/1,000 digital map and local geodetic system coordinates and world geodetic system coordinates that had been used in UIS business of Pusan city and, make a analysis of distortion quantity using KASM Trans Ver 2.2. As the result of distortion quantity calculation about all Pusan city, numbers of area that error is over 0.05m are 35 in case of X(N) and 43 in case of Y(E). Because some business section have especially much error, we divided into 3 areas, that was A,B,C, and analyzed. As a result of analysis, errors of more than 0.05m are occurred only 1 X(E) in the B area and 1 X(N) and 1 Y(E) in the C area. In conclusion, We think It is a good method that we consider a distortion quantity and divide a region, and transfer to world geodetic system for large area like Pusan city.

A Comparative Study of GABA, Glutamate Contents, Acetylcholinesterase Inhibition and Antiradical Activity of the Methanolic Extracts from 10 Edible Plants (10가지 식용식물 추출물의 가바, 글루탐산 함량, 아세틸콜린에스테라제 억제 및 라디컬 소거능 비교)

  • Jung, Yeon-Seop;Park, Sung-Jin;Kim, Ji-Eun;Yang, Seun-Ah;Park, Jung-Hyun;Kim, Jung-Hyun;Jhee, Kwang-Hwan;Lee, Sam-Pin;Lee, In-Seon
    • Korean Journal of Food Science and Technology
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    • v.44 no.4
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    • pp.447-451
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    • 2012
  • In order to investigate the efficacies for cognitive function of edible plants, we measured the inhibitory effects of acetylcholinesterase(AChE) activity, radical scavenging activities, and the contents of GABA and glutamate in the plant extracts. Among the plant extracts, Schizandra chinensis contained the highest GABA 14.8 mg/g and the extracts of Cnidium officinale and Polygonum multiflorum also had a relatively high GABA. On the other hand, plant extracts except, Acorus gramineus, showed similar glutamate contents. S. chinensis, Hovenia dulcis, Thuja orientalis, and Eleutherococcus senticosus exhibited high inhibition against AChE activities at about 18-33% at 1 mg/mL. In addition, strong radical scavenging activities were also detected in those extracts which showed high AChE inhibition. Taken together, H. dulcis, T. orientalis, E. senticosus, and S. chinensis could be effective resources for enhancing cognitive function. Further, it was suggested that the AChE inhibitory activities of plant extracts might be related to antioxidative activity.