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      • Differential Effects of Pioglitazone in the Hippocampal CA1 Region Following Transient Forebrain Ischemia in Low- and High-Fat Diet-Fed Gerbils.

        Moon, Seung Myung,Choi, Goang-Min,Yoo, Dae Young,Jung, Hyo Young,Yim, Hee Sun,Kim, Dae Won,Hwang, In Koo,Cho, Byung Moon,Chang, In Bok,Cho, Sung-Min,Won, Moo-Ho Kluwer Academic/Plenum Publishers 2015 Neurochem Res Vol.40 No.5

        <P>In the present study, we investigated the effects of pioglitazone (PGZ) in the hippocampal CA1 region of low- or high-fat diet (LFD or HFD) fed gerbils after transient forebrain ischemia. After 8 weeks of LFD or HFD feeding, PGZ (30 mg/kg) was intraperitoneally administered to the gerbils, following which ischemia was induced by occlusion of the bilateral common carotid arteries for 5 min. Administration of PGZ significantly reduced the ischemia-induced hyperactivity 1 day after ischemia/reperfusion in both LFD- and HFD-fed gerbils. At 4 days after ischemia/reperfusion, the neurons were significantly reduced and microglial activation was observed in the hippocampal CA1 region in LFD- and HFD-fed gerbils. The microglial activation was more prominent in the HFD-fed gerbils compared to the LFD-fed gerbils. Administration of PGZ ameliorated ischemia-induced neuronal death and microglial activation in the hippocampal CA1 region 4 days after ischemia/reperfusion in the LFD-fed gerbils, but not in the HFD-gerbils. At 6 h after ischemia/reperfusion, tumor necrosis factor-α (TNF-α) and interlukin-1β (IL-1β) levels were significantly increased in the hippocampal homogenates of LFD-fed group compared to control group, and HFD feeding further increased TNF-α and IL-1β levels. PGZ treatment significantly ameliorated the increase of TNF-α and IL-1β levels in LFD-fed gerbils, not in the HFD-fed gerbils. At 12 h after ischemia/reperfusion, superoxide dismutase (SOD) and malondialdehyde (MDA) levels in hippocampal homogenates were significantly increased in the LFD-fed group compared to the control group, and HFD feeding significantly showed relatively reduction in SOD activity and increase in MDA level. PGZ administration significantly reduced the increase in MDA levels 12 h after ischemia/reperfusion in the LFD-fed gerbils, but not in the HFD-fed gerbils. These results suggest that PGZ ameliorates the neuronal damage induced by ischemia by maintaining the TNF-α, IL-1β, SOD and MDA levels in LFD-fed gerbils. In addition, HFD feeding affects the modulation of these parameters in the hippocampus after transient forebrain ischemia.</P>

      • The effects of secondary task on the control of vehicle under driving simulator: a study among 50s taxi drivers

        Han Soo Kim,Jin Seung Choi,Dong Won Kang,Hong Won Yeon,Mi Hyun Choi,Doo Hwan Ji,Byung Chan Min,Soon Cheol Chung,Gye Rae Tack 대한인간공학회 2011 대한인간공학회 학술대회논문집 Vol.2011 No.5

        Objective: The aim of this study is to quantitatively evaluate the effects of the secondary task during simulated driving using the variable indicating control of vehicle. Background: There are so many researches for simulated driving and performance. For instance, some researches show that the effects of cell phone conversations on simulated driving. Cell phone conversations impaired explicit recognition memory. Method: Participants included 50s taxi drivers; 15 males and 15 females. All subjects were instructed to keep a distance (30m) from the car ahead and a constant speed (80km/hr or 100km/hr). Sending text message (STM) and Searching navigation (SN) were selected as the secondary task. Experiment consisted of rest for 3min., driving alone for 1min. and driving with secondary task for 1 min.. We were analyzed anterior-posterior coefficient of variation (APCV) and medial-lateral coefficient of variation (MLCV). Results: APCV was increased by 175.4% in STM and 223.8% in SN at 80km/hr. MLCV was increased by 242.3% in STM and 323.4% in SN at 100km/hr. There was no significant difference between genders. Conclusion: Consequently, performing secondary task during driving impaired the control of vehicle.

      • KCI등재

        온도 유지시간 제어를 적용한 하이브리드 분말 압출 공정을 통한 요구 특성의 스퍼기어 제조

        이경훈(Kyung Hun Lee),황대원(Dae Won Hwang),김병민(Byung Min Kim) 대한기계학회 2011 大韓機械學會論文集A Vol.35 No.8

        본 연구는 압출 시 성형온도를 유지하여 Zn-22Al 합금분말의 성형성을 향상시키는 하이브리드 분말 압출 공정의 개발 및 온도 유지시간이 압출된 스퍼기어의 기계적 특성에 미치는 영향을 조사하기 위해 수행되었다. 피치원 지름 1.8mm 의 소형 스퍼기어는 압출온도 290, 300, 310℃에서 성형되었다. 볼밀시간 32h 의 Zn-22Al 합금분말을 압출온도 310℃에서 압출 시 표면 결함이 없는 소형 기어가 제조되었다. 경도분포는 기어 중심부와 치형부에서 불균일하였고 소결공정 후 내부 변형에너지의 차이로 인해 내부균열이 발생하였다. 위와 같은 문제를 해결하기 위해 온도 유지시간 제어를 이용한 하이브리드 압출 연구를 수행하였다. 압출된 스퍼기어의 평가는 압출하중, 비커스 경도 및 치수정밀도 측정을 통해 이루어졌다. 온도 유지시간 15min 에서 압출된 스퍼기어의 기계적 성질이 가장 우수하였다. In this study, a hybrid powder-extrusion process involving the control of temperature dwelling time for improving the formability of Zn-22Al powder was developed and the effect of dwelling time on the mechanical properties of a spur gear with a pitch circle having a diameter of 1.8 mm was investigated. General extrusion experiments were carried out at different temperatures such as 290, 300, and 310°C. Spur gears with good qualities and without any surface defects were obtained in the case of extrusion temperature of 310°C and ball-milling duration of 32 h. The Vickers hardness distribution was non-uniform, and after the sintering process, an internal crack was generated because of the different deformation energy between gear central part and teeth. To overcome the abovementioned problems, research on controlling the dwelling time of the extrusion temperature in the powder-extrusion process was carried out. Good-quality spur gears were obtained when the dwelling time was 15 min.

      • KCI등재

        Improvement and Application for Environmental Conservation Value Assessment Map(ECVAM) of Nationwide Land in Korea

        Lee, Moung-Jin,Jeon, Seong-Woo,Jo, Min-Jeong,Song, Won-Kyong,Kang, Byung-Jin The Korean Society of Remote Sensing 2007 大韓遠隔探査學會誌 Vol.23 No.5

        This study is aiming at improving the Environmental Conservation Value Assessment Map(ECVAM) of National Land in Korea. The ECVAM items are composed of legal and environmental/ecological assessments. A popular method applied to ECVAM is an overlay environmental/ecological assessment items. The purpose of this study is to offer complementary items of the ECVAM by examining assessment items. In this study we assessed the ECVAM by five methods. Method 1 is Grade 1 areas of each administrative district; Method 2 is comparing overlapped areas of each assessment items Grade 1, 2 and permission of each assessment items duplication; Method 3 is Grade 1, 2 areas by only singular assessment items; Method 4 is Grade 1 areas only of Method 2; and Method 5 is Grade 2 areas only of Method 2. Method 1 showed Seoul and other metropolitan cities revealed a large proportion of Grade I regions by the legal assessment items. Gang won-Do, showed a large proportion of Grade I regions by the environmental/ecological assessment item. Method 2 showed 93.4% of diameter Grade II(standard for stability); forest diameter item accounted for 99.9% by Method 3, Method 4 showed 95.7% of forest diameter, and forest density accounted for 66.4% by Method 5. This study contributes to reduce the complexity in the process of manufacturing ECVAM of National Land, and to raise the flexibility in the process of managing and updating this map.

      • KCI등재

        Improvement and Application for Environmental Conservation Value Assessment Map (ECVAM) of Nationwide Land in Korea

        Moung Jin Lee,Seong Woo Jeon,Min Jeong Jo,Won Kyong Song,Byung Jin Kang 大韓遠隔探査學會 2007 大韓遠隔探査學會誌 Vol.23 No.5

        This study is aiming at improving the Environmental Conservation Value Assessment Map (ECVAM) of National Land in Korea. The ECVAM items are composed of legal and environmental/ecological assessments. A popular method applied to ECVAM is an overlay environmental/ecological assessment items. The purpose of this study is to offer complementary items of the ECVAM by examining assessment items. In this study we assessed the ECVAM by five methods. Method 1 is Grade 1 areas of each administrative district; Method 2 is comparing overlapped areas of each assessment items Grade 1, 2 and permission of each assessment items duplication; Method 3 is Grade 1, 2 areas by only singular assessment items; Method 4 is Grade 1 areas only of Method 2; and Method 5 is Grade 2 areas only of Method 2. Method 1 showed Seoul and other metropolitan cities revealed a large proportion of Grade I regions by the legal assessment items. Gang won-Do, showed a large proportion of Grade I regions by the environmental/ecological assessment item. Method 2 showed 93.4 % of diameter Grade II (standard for stability); forest diameter item accounted for 99.9 % by Method 3, Method 4 showed 95.7 % of forest diameter, and forest density accounted for 66.4 % by Method 5. This study contributes to reduce the complexity in the process of manufacturing ECVAM of National Land, and to raise the flexibility in the process of managing and updating this map.

      • KCI등재

        재사용이 가능한 나노복합재료 Fe<sub>3</sub>O<sub>4</sub>-ACCS-Ag의 제조 및 항균 특성 평가

        심재홍,김해원,김진원,서영석,오세강,조민,박정희,오병택,Shim, Jaehong,Kim, Hea-Won,Kim, Jin-Won,Seo, Young-Seok,Oh, Sae-Gang,Cho, Min,Park, Junghee,Oh, Byung-Taek 한국지하수토양환경학회 2015 지하수토양환경 Vol.20 No.3

        In this study, Fe<sub>3</sub>O<sub>4</sub>-ACCS-Ag nanoparticles (NPs) were successfully synthesized using silica extracted from corn cob ash. The synthesized Fe<sub>3</sub>O<sub>4</sub>-ACCS-Ag NPs were characterized using X-ray diffraction (XRD), scanning electron microscopyenergy dispersive X-ray spectroscopy (SEM-EDX), transmission electron microscopy (TEM) and fourier transform infrared spectroscopy (FTIR). In addition, the potential application of Fe<sub>3</sub>O<sub>4</sub>-ACCS-Ag NPs as an antibacterial material in water disinfection was investigated using Escherichia coli ATCC 8739 as model bacteria. The antibacterial activity of synthesized composite material showed 99.9% antibacterial effect within 20 min for the tested bacteria. From this experiment, the synthesized Fe<sub>3</sub>O<sub>4</sub>-ACCS-Ag nanocomposites also hold magnetic properties and could be easily recovered from the water solution for its reuse. The reused nanocomposites presented the decreasing antibacterial efficiencies with the reuse cycle but the composite used three times still killed 90% of bacteria in 20 min.

      • In Vitro Development of Mouse Parthenogenetic Embryos: Effect of Temperature before Oocyte Activation

        Roh Sangho,Won Cheolhee,Min Byung-Moo 한국동물생명공학회(구 한국동물번식학회) 2005 Reproductive & Developmental Biology(Supplement) Vol.29 No.2s

        This study was conducted to establish the optimal temperature condition before oocyte activation in B6D2 F1 mouse. In experiment 1, two embryo culture media (CZB vs KSOM) were evaluated for the development of activated mouse oocytes. Parthenogenetic embryos cultured in KSOM showed better blastocyst development than ones cultured in CZB(56.2% vs 81.0%, p<0.01). Two-hour of pre-incubation before activation significantly reduced the number of hatched blastocysts in KSOM (22.0% versus 8.8%, p<0.05). In experiment 2, recovered oocytes were pre-incubated at different temperature conditions before activation. The experimental groups were divided by 5 as follows. Group A: pre-incubation for 120 min at 37℃, Group B: pre-incubation at 37℃ for 90 min then at 25℃ for 30 min, Group C: pre-incubation at 37℃ for 60 min then at 25℃ for 60 min, Group D: pre-incubation at 37℃ for 30 min then at 25℃ for 90 min, and Group E: pre-incubation at 25℃ for 120 min before activation. Group A (67.6%) and B (66.7%) showed better development to the blastocyst stage than other groups (Group C: 50.0%, Group D: 49.2%, Group E: 33.3%, p<0.05). The present study indicates that the temperature before activation affects the development of B6D2 F1 mouse parthenogenetic oocytes and exposure to room temperature should be limited to 30-min when the oocytes are left in HEPES-buffered medium for micromanipulation.

      • KCI등재

        Melting Characteristics for Radioactive Aluminum Wastes in Electric Arc Furnace

        Byung-Youn Min,Pyung-Seob Song,Jun-Hyung Ahn,Wang-Kyu Choi,Chong-Hun Jung,Won-Zin Oh,Yong Kang 한국방사성폐기물학회 2006 방사성폐기물학회지 Vol.4 No.1

        한국원자력연구소 내의 연구용 원자로(TRIGA II, III) 해체 시 발생한 방사성 알루미늄 해체 폐기물의 감용 및 제염 특성을 평가하기 위해 아크로에서 알루미늄의 용융 특성 및 방사성 핵종의 분배 특성에 대한 연구를 수행하였다. 알루미늄 폐기물은 흑연전극(graphite electrode)을 이용한 전기아크로에서 4가지 종류의 플럭스를 함께 첨가하여 용융시켰다. 또한 알루미늄의 용융 시 방사성 핵종의 분배 특성을 고찰하기 위해 알루미늄 시편에 방사성 모의 핵종인 코발트, 세슘, 스트론튬의 화합물을 오염시킨 후 혹연도가니에 넣어 알루미늄 용융실험을 수행하였다. 전기아크로에서 알루미늄의 용융실험을 수행한 결과 플럭스의 종류에 따라 다소 차이는 있으나 플럭스의 첨가에 의해 알루미늄 용융체의 유동성이 증가됨을 확인할 수 있었다. 아크 용융에 의해 생성된 슬래그의 발생량은 플럭스 A와 B를 첨가한 알루미늄 용융실험에 비해 플럭스 C와 D를 첨가한 실험에서 상대적으로 많은 양이 생성됨을 알 수 있었으며, 첨가된 플럭스의 양이 증가할수록 이에 비례하여 슬래그의 발생량이 증가함을 알 수 있었다. 슬래그(slag)의 XRD 분석을 통해 방사성 핵종이 주괴에서 슬래그 상으로 이동한 후 슬래그를 구성하고 있는 산화알루미늄과 결합하여 안정한 화합물로 슬래그 상에 포집됨을 알 수 있었다. 알루미늄 폐기물의 용융시 Co의 분배율은 플럭스를 첨가한 경우에 보다 높은 제염계수를 나타냈으며, 모든 플럭스에서 40% 이상의 제염 효과를 나타내었다. 반면에 휘발성 핵종인 Cs과 Sr은 주괴로부터 98% 이상이 제거되어 대부분이 슬래그상과 분진으로 이동되는 특성을 확인할 수 있었다. The characteristics of the aluminum waste melting and the distribution of the radioactive nuclides have been investigated for the estimation on the volume reduction and the decontamination of the aluminum wastes from the decommissioning of the TRIGA MARK it and III research reactors at the Korea Atomic Energy Research Institute(KAERI). The aluminum wastes were melted with the use of the fluxes such as flux , and flux in the DC graphite arc furnace. For the assessment of the distribution of the radioactive nuclides during the melting of the aluminum, the aluminum materials were contaminated by the surrogate nuclides such as cobalt(Co), cesium(Cs) and strontium(Sr). The fluidity of aluminum melt was increased with the addition of the fluxes, which has slight difference according to the type of fluxes. The formation of the slag during the aluminum melting added the flux type C and D was larger than that with the flux A and B. The rate of the slag formation linearly increased with increasing the flux concentration. The results of the XRD analysis showed that the surrogate nuclide was transferred to the slag, which can be easily separated from the melt and then they combined with aluminum oxide to form a more stable compound. The distribution ratio of cobalt in ingot to that in slag was more than 40% at all types of fluxes. Since vapor pressures of cesium and strontium were higher than those that of the host metals at the melting temperature, their removal efficiency from the ingot phase to the slag and the dust phase was by up to 98%.

      • KCI등재

        A Study on the Performance Evaluation of Standard Gamma Irradiation System Using Monte Carlo Code

        Won-Seok Park(박원석),Seung-Uk Heo(허승욱),Jang-Oh Kim(김장오),Byung-In Min(민병인) 한국방사선학회 2018 한국방사선학회 논문지 Vol.12 No.2

        In this study, we compared the measured values of the effective beam size of standard gamma irradiator with the simulation results to provide a useful means to the effective beam area determination. Results of the simulation and measured using ion chamber was distributed in a relative error of 4.5 ~ 7.3% of the case of air kerma rate. The size of the effective beam area is when the simulation was implemented in the horizontal direction 27cm, 21.6cm vertical direction, the measured result using a film was obtained similar results with the horizontal direction 26.5cm, 21.9cm vertical direction. The relative error in the horizontal direction is 1.85% and 1.38% vertical effective beam area was also similarly distributed around the field gamma rays. As a result of the study, it was confirmed that the effectiveness of the simulation was sufficient for the gamma irradiation system. In particular, it is small relative errors in the effective beam size than the air kerma rate is considered to be due to the size of the beam is determined by geometric factors rather than the capacity of the standard source. A further study is needed to improve the reliability of the photon energy distribution diagram using simulation. 본 연구는 표준 감마선 조사장치의 유효빔 크기를 실측과 시뮬레이션의 결과를 비교하여 유효빔 영역의 결정에 유용한 수단을 제공하고자 하였다. 시뮬레이션과 전리함을 이용한 실측의 결과는 공기커마율의 경우는 상대오차 4.5~7.3% 범위에 분포하였다. 유효빔 영역의 크기는 시뮬레이션의 경우 수평 방향 27cm, 수직 방향 21.6cm로 구현되었고, 필름을 이용한 실측결과는 수평 방향 26.5cm, 수직 방향 21.9cm로 유사한 결과가 도출되었다. 수평방향의 상대오차 는 1.85%, 수직 방향은 1.38% 이며 유효빔 영역도 감마선장을 중심으로 유사하게 분포하였다. 감마선 조사장치에 있어서 시뮬레이션의 유효성이 충분함을 확인하였다. 특히 공기커마율보다 유효빔 크기의 상대오차가 적은 것은 빔의 크기가 표준선원의 용량보다는 기하학적 요인으로 결정되기 때문인 것으로 판단된다. 향후 시뮬레이션을 이용한 광자 에너지 분포도의 신뢰성을 높이기 위한 연구가 필요할 것 이다.

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