• Title/Summary/Keyword: 박봉수

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Monte-Carlo Simulation for GEO-KOMPSAT2 Orbit Determination Accuracy (Monte-Carlo 시뮬레이션을 통한 정지궤도복합위성 궤도결정 정밀도 해석)

  • Park, Bong-Kyu;Ahn, Sang Il;Kim, Bang Yeop
    • Aerospace Engineering and Technology
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    • v.12 no.2
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    • pp.40-47
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    • 2013
  • GEO-KOMPSAT2 shall be designed to produce higher quality of image than that of COMS, and this requires the ground system to provide orbit data with high accuracy; better than 2km which is sort of high accuracy when it comes to geostationary satellite. For GEO-KOMPSAT2, KARI is planning to use ranging data for orbit determination, obtained from two ranging stations located in KARI and oversea country with long longitudinal baseline. This paper estimated achievable orbit determination accuracy using covariance analysis under assumption of using two ranging stations; SOC and available secondary tracking stations located in oversea countries. In addition to covariance analysis, in order to validate the analysis, the Monte-Carlo simulation has been performed and compared to the covariance analysis.

Effect of Anti-washout Admixture Implementation on Backfill Aggregates on Underwater Structures (수중 구조물 골재 속채움 시 수중 불분리성 혼화제의 적용 효과)

  • Kim, Ukgie;Choi, Changho;Park, Bonggeun;Li, Zhuang;Cho, Samdeok
    • Journal of the Korean GEO-environmental Society
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    • v.15 no.9
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    • pp.59-67
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    • 2014
  • With increasing underwater structure construction, there is high interest in offshore foundation and underwater grout and various study has been done in this area. For grout materials constructed underwater, it may be washed away by water or easily disturbed and material separation phenomenon during curing period always happens. As a result, it is difficult to ensure construction quality and this has a significant influence on the design strength of structure. In this study, to understand application effects of anti-washout admixture for the preplaced construction method, where grout is injected in monopile after filled with aggregates, laboratory tests on bleeding and compressive strength of anti-washout admixture were performed under various test conditions varying size of aggregate, water and cement ratio and admixture, and test results were compared and evaluated.

Effects of Bikihuan (BKH) on anti-angiogenesis (비기환이 신생혈관형성 억제에 미치는 효과)

  • Kim, Dae-Jun;Park, Bong-Ky;Lee, Yeon-Wall;Yoo, Hwa-Seung;Han, Sung-Soo;Cho, Chong-Guan
    • Journal of Korean Traditional Oncology
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    • v.13 no.1
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    • pp.13-24
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    • 2008
  • Objective: To evaluate the effects of Bikihaun (BKH) on angiogenesis. Method: We examined the anti-angiogenic effect of BKH in invasion assay model. We performed proliferation assay, migration assay, tube formation assay and Chicken Chorioallantoic Membrane (CAM) assay. Results: In proliferation assay, at lower dose under 125 ${\mu}g/m{\ell}$ anti-angiogenesis effect of the group treated BKH made no difference with the control group. But, at the dose of 250 ${\mu}g/m{\ell}$ or more anti-angiogenesis effect of the group treated BKH showed more effective as compared to the control group. In migration assay, BKH did not affect migration of vascular endothelial cell. In tube formation assay, at lower dose under 100 ${\mu}g/m{\ell}$ showed mild effect of anti-tube formation. But, at the dose of 1000 ${\mu}g/m{\ell}$ showed more effective anti-tube formation. In CAM assay, BKH showed anti-angiogenesis effect at the dose of 10 ${\mu}g/m{\ell}$. Conclusion: BKH has antiangiogenetic properties in vitro.

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The Optimization Mechanism of CPU/GPU Computing Resource for Minimization of Performance Interference and Calculation Efficiency in Volunteer Computing Environment (볼런티어 컴퓨팅 환경에서 성능간섭 최소화와 연산 효율성 증대를 위한 CPU/GPU 컴퓨팅 자원 최적화 기법)

  • Bak, Bong Woo;Song, Chung Geon;Yu, Heon Chang
    • KIPS Transactions on Computer and Communication Systems
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    • v.6 no.12
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    • pp.479-486
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    • 2017
  • Volunteer computing is a new computing paradigm that performs operations on idle resources of many nodes. The operation method of the client application for the execution of the volunteer computing is determined by the setting information of the user. Ideal operation requires optimized settings for system features and operating methods of other applications. In this paper, we analyze the usage ratio of CPU and GPU periodically, and develop a manager that dynamically applies optimized options. Through our proposed mechanism, the performance of the task computing is higher than that of the existing Volunteer Computing, and the performance interference is minimized. It is expected that volunteers will be able to provide higher computing resources for Volunteer Computing Project.

Isolation of akabane virus and its molecular diagnosis by reverse transcription polymerase chain reaction (아까바네 바이러스의 분리 및 RT-PCR 진단법에 관한 연구)

  • Cho, Jae-jin;Lee, Chung-gil;Park, Bong-kyun;Chang, Chung-ho;Chung, Chung-won;Cho, In-soo;An, Soo-hwan
    • Korean Journal of Veterinary Research
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    • v.40 no.1
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    • pp.42-48
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    • 2000
  • Akabane disease is transmitted through mosquitoes in cattle, sheep and goats. It shows congenital abnormalities including encephalomyetitis, hydranencephaly, neurogenic arthrogryposis, and deformed neonatal calves. Akabane viruses, 93FMX and K-9 strain, were isolated from fetal matrix of aborted cow and blood of healthy cow, respectively. S gene sequences of 93FMX and K-9 showed 100% homology with that of OBE-1 strain isolated in Japan. Based upon our sequencing data, we synthesized specific primers for PCR diagnosis. Using these primers, we were able to amplify the S gene of Akabane virus not only from the culture fluid of Vero cells but also from the brain tissue of suckling mouse inoculated with, Akabane virus. These PCR products were confirmed by Southern blot hybridization. Not only the sensitivity of PCR test was high enough to detect the viruses of $10^{1.0}TCID_{50}/ml$, but also the time for diagnosis was significantly shorter than that of the virus isolation by tissue culture method. This method was also effective for the detection of Akabane virus in the cerebrum of fetus. RT-PCR method may be used for a useful diagnostic test of the clinical cases of Akabane disease.

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A Study on the Evaluation of Stream Naturalness for Stream Corridor (우리나라의 하천특성을 고려한 하천자연도평가)

  • Park, Bong Jin;Lee, Jun Yeol;Sung, Young Du
    • Proceedings of the Korea Water Resources Association Conference
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    • 2004.05b
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    • pp.516-520
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    • 2004
  • Stream Naturalness means the index of natural state in stream's ecosystem. The evaluation of stream naturalness can evaluate relatively the effect of environmental damages by human and to show how significantly current stream has been apart from its natural state. And it could be show what is the meaning of importance in stream's ecosystem by such distinctions and it Is done by showing the need how a large scale of action for restoration to be restored to natural state of stream system. In this study, a set of index for Stream Naturalness evaluation is proposed, which is referred to and modified problems with domestic and foreign study cases. This methodology is supposed to show well the characteristics of stream in Korea. A case study of Hong-Chun River shows how this methodology is applied to the Stream Naturalness evaluation. For improving the function of river which are water use and flood control and for preserving the function of inhabitation, the proposed methodology is expected to be used a index of direction for a environmental project related stream improvement by evaluation of ecologically sound function in streams.

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Orientation States of Ferroelectric Domains and {111} Twins in $BaTiO_3$ ($BaTiO_3$의 {111}쌍정계면과 강유전 분역의 배향성)

  • 박봉모;정수진
    • Journal of the Korean Ceramic Society
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    • v.33 no.2
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    • pp.228-234
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    • 1996
  • It is very important to understand the domain structures of ferroelectric BaTiO3 in the poling process. Especially because {111} twinning is frequently observed in most BaTiO3 ceramics it is required to know the relations between the ferroelectric domains and the structural twin. In this study the domain structures of a {111} twinned crystal sample were observed under a polarizing microscope. and the relation between the {111} twin and the domain configurations could be classified into two types of 'V'-shape and linear shape penetrating perpendicular to the twin boundary. Domain formation obeys the symmetry of the {111} twining when a new domain structure is developed by heat treatment and surface deformation due to domain formation is also occured symmetrically between the both sides of the{111} twin boundary. This symmetrical behavior of the domains could be interpreted with the "head-to-tall" orientation of the domains across the {111} twin boundary.

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A Study on the Sandbar and Vegetation Area Alteration at the Downstream of Dam (댐 하류하천의 사주와 식생 면적 변화에 관한 연구)

  • Park, Bong-Jin;Jang, Chang-Lae;Lee, Sam-Hee;Jung, Kwan-Sue
    • Journal of Korea Water Resources Association
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    • v.41 no.12
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    • pp.1163-1172
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    • 2008
  • In this study, area variation, index and degree of alteration, temporal variation of the sandbar and vegetation were analyzed using aerial photographs during the pre and post dam construction at the downstream of dam. Analysis result of the sandbar area was decreased 17 %. Sandbar area was 38 % of the channel areas at the pre dam, but 21 % at the post dam. Alteration indies of the sandbar were $-0.9921{\sim}2.9528$. Analysis result of the vegetation area was increased 13 %. Vegetation area was 11 % of the channel areas at the pre dam, but 24 % at the post dam. Alteration indies of the vegetation were $-0.8908{\sim}12.0736$. Temporal variation of the sandbar and vegetation were analyized at the An Dong dam, Im Ha dam, Hap Chun dam. Analysis result of the sandbar was decreased $42,600m^2$ per year, but vegetation was increased $51,700m^2$ per year. Sandbar area was decreasing more fast than vegetation area increasing.

Biodegradation of JP-8 by Rhodococcus fascians Isolated from Petroleum Contaminated Soil (유류 오염 토양에서 분리된 Rhodococcus fascians를 이용한 JP-8의 분해 특성)

  • Nam, Bo Hyun;Park, Bong Je;Yun, Hyun Shik
    • Korean Chemical Engineering Research
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    • v.46 no.4
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    • pp.819-823
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    • 2008
  • Microorganisms isolated from petroleum contaminated site were tested for their ability to grow on JP-8 by culturing them on the culture medium that contains JP-8 as a carbon source. The microorganism which grew on JP-8 containing minimal salt medium was separated and identified as Rhodococcus fascians. Changes in JP-8 biodegradation of R. fascians that was isolated from petroleum contaminated site was investigated with various inoculums sizes, JP-8 concentrations, medium pHs, and culture temperatures. The amount of JP-8 was analyzed by TPH using Gas Chromatography.

The Effects of Followership of Coffee Speciality Members on LMX, Knowledge Sharing, and Job Attitude (커피전문점 직원의 팔로워십이 리더-구성원 교환관계, 지식공유 및 직무태도에 미치는 영향)

  • Kim, Ri-Kyung;Park, Bong-Gyu
    • Journal of Digital Convergence
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    • v.14 no.7
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    • pp.73-81
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    • 2016
  • This study examined the effects of followership characteristics on LMX, knowledge sharing, job satisfaction and turnover intention for coffee speciality store members. 317 questionnaire samples are used to test 4 hypotheses using structural equation model with AMOS. Results of hypotheses testing are as follows: First, goal congruence and active participation factors of followership characteristics influence positively LMX. Second, LMX influences positively knowledge sharing, and knowledge influences job satisfaction and turnover intention. This study emphasizes the importance of knowledge sharing in coffee speciality store members relations. In addition, this study shows that followership, LMX, knowledge sharing are important for members' increasing job satisfaction and decreasing turnover intention, and human resource management. Implications and limitations of this study were also suggested.