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      • 생태학적 위기와 현대교육의 과제

        노상우,최진봉,김관수 全北大學校 敎育大學院 2003 敎育論叢 Vol.23 No.-

        This paper diagnoses the cause of ecological crisis human beings encounter at present, looks into the ecological viewpoint as an alternative, and discusses the educational task to overcome the present crisis. First, this paper looked into the ecologists' diagnosis of the cause of ecological crisis, focusing on the problem of western christian viewpoint of nature, western dualistic epistemology, and the blind faith in the progress. Second. the discussion of ecological standpoint to overcome the ecological crisis included "deep ecology" and Bookchin's "social ecology". Third, on the basis of these standpoints, the task of new eco-ethical education was suggested. As a result, this paper insisted the urgency to internalize the ethics of responsibility for the life-giving of the whole ecology related to one's life by making individuals and community turn their recognition for the solution of the ecological problems and produce the proenvironmental activity-orientedness.

      • KCI등재

        천연가스 사용 난방 및 산업보일러의 NOx와 CO 배출계수 산정 연구

        장영기,최상진,김관,송기봉,김호정,정봉진 한국대기환경학회 2004 한국대기환경학회지 Vol.20 No.5

        This study was conducted for developing the emission factors of nitrogen oxide(NOx) and carbon monoxide (CO) from the combustion boilers burning liquefied natural gas (LNG). These emission factors were compared with those of U.S. EPA and European Environment Agency (EEA). NOx and CO concentration in the flow gas were measured using Kane-May, KM9106 and Thermo Environmental Instruments Inc., 42C-HL. Measurement were conducted at thirty industrial and commercial LNG boilers. Emission factors were calculated on the basis of fuel consumption (kg-pollutant/㎥-fuel burned). NOx concentration at industrial boiler was 14~125 ppm and it was measured as 35~125 ppm at commercial boiler. NOx emission factors of industrial boiler and commercial boiler were 1.84kg/㎥ and 2.09kg/㎥, respectively. NOx emission factor of commercial boiler was higher than that of industrial boiler. The NOx emission factors estimated in this study were lower than those of U.S. EPA and higher than those of EEA. Average CO emission factor of industrial boiler was 0.65 kg/㎥ and at commercial boiler it was 0.70kg/㎥, CO emission factor at industrial boiler was lower than that at commercial boiler.

      • KCI등재후보

        양성 백악아세포종의 치험례

        김종배,박효상,최봉주,이용규,남동석,박관수 啓明大學校 醫科大學 1997 계명의대학술지 Vol.16 No.2

        Benign cementoblastoma is uncommon odontogenic tumor of the jaw of mesenchymal origin. It is common in male below 25 years of age, commonly occurs in mandibular molar and premolar area. Principal symptom is painless swelling. Radiologically, radiopaque mass is fused with a root or roots of teeth, surrounded, and limited peripherally by a radiolucent halo. Histologically, the tumor is composed of sheets of an osteocementum like material with basophilic reversal line. Because of unlimited growth potential, the usual treatment is complete surgical excision with extraction of the associated teeth. The patient, 16-year old male, was admitted to our hospital with chief complaint of painless swelling on right mandible body area. Surgical excision of lesion and extraction of associated tooth was performed. On follow up check, we obtained good result without any signs of recurrence of the lesion.

      • New Faunistic Data of Tortricinae (Lepidoptera, Tortricidae) for the North Korean Fauna

        Bong-Kyu Byun,Bong-Woo Lee,Kwan-Ho Bae,Jun-Keun Choi,Ha Yong Choi 한국응용곤충학회 2012 한국응용곤충학회 학술대회논문집 Vol.2012 No.10

        The first record of the subfamily Tortricinae from North Korea was reported by Zhu (1969), comprising 17 species. Later Park and Byun (1991) added 11 species of the subfamily. And Park and Razowski (1991) added 16 species of the tribe Tortricini. Jaros et al. (1992) reported 11 species of Tortricinae from North Korea, based on the material Czech Academy of Sciences, Prague, Czech Republic(CAS). Byun et al. (1998) enumerated 350 species of Korean Tortricidae, citing 63 species of Tortricinae and 40 species of Olethreutinae from North Korea. Later Razowski (1999) provided a list of Korean Tortricidae with 176 of North Korea. Despite these studies, much of the North Korean Tortricidae deposited in the HNHM remained unstudied. Recently the first author examined the totricid material in the HNHM and reported 7 newly recorded species from North Korea (Byun et al., 2007). In the present study, we provide the faunistic information for ten species of Tortricinae, including their localities. This study was carried out under the support of Korea National Arboretum and Korea Forestry Research Institute.

      • KCI등재

        A Study on Accuracy Improvement of SBAS Ionospheric Correction Using Electron Density Distribution Model

        Choi, Bong-Kwan,Han, Deok-Hwa,Kim, Dong-Uk,Kee, Changdon The Institute of Positioning 2019 Journal of Positioning, Navigation, and Timing Vol.8 No.2

        This paper proposed a method to estimate the vertical delay from the slant delay, which can improve accuracy of the ionospheric correction of SBAS. Proposed method used Chapman profile which is a model for the vertical electron density distribution of the ionosphere. In the proposed method, we assumed that parameters of Chapman profile are given and the vertical ionospheric can be modeled with linear function. We also divided ionosphere into multi-layer. For the verification, we converted slant ionospheric delays to vertical ionospheric delays by using the proposed method and generated the ionospheric correction of SBAS with vertical delays. We used International Reference Ionosphere (IRI) model for the simulation to verification. As a result, the accuracy of ionospheric correction from proposed method has been improved for 17.3% in daytime, 10.2% in evening, 2.1% in nighttime, compared with correction from thin shell model. Finally, we verified the method in the SBAS user domain, by comparing slant ionospheric delays of users. Using the proposed method, root mean square value of slant delay error decreased for 23.6% and max error value decreased for 27.2%.

      • SCISCIESCOPUS

        Effect of Bimetallic Ni-Cr Catalysts for Steam-CO2 Reforming of Methane at High Pressure.

        Choi, Bong Kwan,Park, Yoon Hwa,Moon, Dong Ju,Park, Nam Cook,Kim, Young Chul American Scientific Publishers 2015 Journal of nanoscience and nanotechnology Vol.15 No.7

        <P>The present work was to carry out the development of high performance Ni-based catalyst for Steam-CO2 reforming of methane (SCR) which is suitable for Fischer-Tropsch synthesis of GTL- FPSO (floating, production, storage and offloading) process. The bimetallic Ni-Cr catalysts were prepared by co-impregnation method. The Ni and Cr loading amount were fixed at 12 wt% and 3~7 wt%, respectively. The catalytic reaction was conducted at 900 °C and 20 bar with reactant feed ratio of CH4:CO2:H2O:Ar = 1:0.8:1.3:1 and GHSV = 25,000 h(-1). The Cr-modified Ni/관-Al2O3 catalyst was characterized by BET surface area analysis, X-ray diffraction (XRD), H2-temperature programmed reduction (TPR), H2-chmisorption, CO2-temperature programmed desorption (TPD) and Transmission electron microscopy(TEM). To confirm the amount and type of the carbon deposition, the used catalysts were examined by Thermogravitic analysis (TGA) and Field emission-scanning microscopy/Energy dispersive X-ray analysis (FE-SEM/EDX). It was found that the bimetallic Ni-Cr catalyst exhibits highly dispersed Ni particles with strong metal-to-support interaction (SMSI) as well as excellent catalytic activity, resulting in the suppression of Ni sintering and carbon deposition.</P>

      • Reduction of ischemia-induced cerebral injury by all-trans-retinoic acid

        Choi, Byung-Kwan,Kim, Ji-Hoon,Jung, Jong-Soo,Lee, Young-Suk,Han, Myoung-Eun,Baek, Sun-Yong,Kim, Bong-Seon,Kim, Jae-Bong,Oh, Sae-Ock Springer-Verlag 2009 Experimental brain research Vol.193 No.4

        <P>Ischemia-induced cerebral injury evolves over a longer period than previously believed through post-ischemic inflammation. Retinoic acid (RA) has been shown to exert cytoprotective effects on several cells, but its effects on ischemia-induced cerebral injury have been poorly characterized. The aim of the present study was to examine the effects of all-trans-RA on ischemia-induced cerebral injury and elucidate the underlying mechanism. All-trans-RA treatment reduced the size of the ischemia-induced cerebral infarct. To elucidate the underlying mechanism, ischemia-induced cerebral inflammation was studied by examination of expressions of interleukin 1 beta (IL-1 beta) and ED-1. RA treatment significantly reduced the cerebral inflammation. Moreover, cerebral ischemic induction of cyclooxygenase-2 (COX-2) and CCAAT/enhancer binding protein beta (C/EBP beta), which binds to the COX-2 promoter, was also inhibited by RA. These results suggest that RA can reduce ischemia-induced cerebral injury by an anti-inflammatory action, which may be effected via inhibition of C/EBP beta-mediated COX-2 induction.</P>

      • SCISCIESCOPUS

        Carbon Deposition from the CO2-Steam Reforming of Methane Over Modified Ni/관-Al2O3 Catalysts.

        Choi, Bong Kwan,Ok, Hye Jeong,Moon, Dong Ju,Kim, Jong Ho,Park, Nam Cook,Kim, Young Chul American Scientific Publishers 2015 Journal of nanoscience and nanotechnology Vol.15 No.1

        <P>The aim of this work is to study the catalytic activity and suppression of carbon deposition in the CO2-Steam reforming of methane (SCR) to develop a high performance catalyst for GTL-FPSO application which is required to high pressure (20 bar) for F-T synthesis. Ni/La-X(6)/Al2O3 (X = Ce, Mg, Zr) catalysts were prepared by the impregnation method. The catalytic reaction was studied in a fixed bed reactor system at high pressure. X-ray diffraction (XRD), BET specific surface area and H2-temperature programmed reduction (TPR) were used to observe the characteristics of the prepared catalysts. The carbon deposition and the carbon amount in the used catalysts were examined by SEM and TGA, respectively. As a result, it was found that the Ni/La-Mg(6)/Al2O3 catalyst showed the highest activity and high carbon resistance. The highest activity in Ni/La-Mg(6)/Al2O3 was attributed to the proper Mg loading. It also had the lowest Ni particle and formed relatively stable MgAl2O4, which have an effect on the catalytic activity.</P>

      • KCI등재

        KASS 가용성 성능 평가를 위한 MATLAB GUI 기반 소프트웨어 설계

        최봉관 ( Bong-kwan Choi ),한덕화 ( Deok-hwa Han ),김동욱 ( Dong-uk Kim ),김정범 ( Jung-beom Kim ),기창돈 ( Chang-don Kee ) 한국항행학회 2018 韓國航行學會論文誌 Vol.22 No.5

        본 논문에서는 KASS (korea augmentation satellite system) 의 가용성 성능 평가를 위한 MATLAB GUI (graphical user interface)기반의 소프트웨어에 대해 소개한다. 본 소프트웨어는 MV (minimum variance) estimator 와 Kriging 알고리즘을 이용해 한반도 지역의 지상 사용자 및 항공기 사용자에 대해 UDRE (user differential range error) 와 GIVE (grid ionospheric vertical error) 와 같은 무결성 정보를 생성한다. 또한 본 소프트웨어는 생성한 정보를 이용하여 사용자의 각 위치에 대해 정확도, 보호 수준, 가용성 지도를 제공한다. 특히 항공기 경로에 대해 경로에 따른 보호 수준 값을 계산하는 기능을 수행한다. 항공기 사용자에 대한 보호 수준 값 계산 결과는 EGNOS (european geostationary navigation overlay service) 의 시뮬레이션 툴인 SBASimulator#2의 결과와 비교하여 검증하였다. 그 결과 본 소프트웨어가 생성한 보호 수준의 값의 오차가 약 2% 정도로 정확하게 나온 것을 확인하였다. This paper introduces a MATLAB graphical user interface (GUI) based software for analysis of korea augmentation satellite system (KASS) availability performance. This software uses minimum variance (MV) estimator and Kriging algorithm to generate integrity information such as user differential range error (UDRE) and grid ionospheric vertical error (GIVE). The information is offered to ground and aviation users in Korean region. The software also gives accuracy data, protection level data and availability map about each user position by using the integrity information. In particular the software calculates the protection level along a path of aircraft. We verified the result of protection level of aviation user by comparing them with the results of SBASimulator#2, which is a simulation tool of european geostationary navigation overlay service (EGNOS). As a result, the protection level error between the result of our software and the SBASimulator#2 was about 2% which means that the result of our software is accurate.

      • KCI등재후보

        Identification of genomic regions associated with piglet survival and mortality

        Yoon-Jung Choi, Sang-Wook Kim, Joon-Ho Yoon, Bong-Hwan Choi, Tae-Hun Kim, Kwan-Suk Kim 충북대학교 동물의학연구소 2014 Journal of Biomedical and Translational Research Vol.15 No.2

        One of the major problems in the modern pig industry is infectious disease. Susceptibility to infectious diseases is influenced by both constitutional (e.g. genotype, age, gender, and reproductive status) and environmental factors (e.g. nutrition, management, infections, and other forms of stress). Genetic variations within individual animals or herds can cause differences in the execution of immune functions against infectious agents in domestic pigs. The objectives of the present study were to identify genetic factor(s) responsible for piglet survival and mortality under commercial field conditions with infectious diseases as well as determine QTL regions for immune capacity in a pig reference family. Sex ratio was examined between normal grown and presumed dead groups of F2 animals generated by Korean native pigs (KNP) and Yorkshire (YS) breeds. The ratio of males was significantly higher in the presumed dead group than in the normal grown group. In order to study genetic factors associated with presumed mortality under disease outbreak, allelic frequencies of 239 single nucleotide polymorphisms (SNPs) were compared between normal grown and presumed dead groups. Exactly 22 SNPs showed significant differences in their allelic frequencies between the two groups, and four of them were validated with another commercial population divided by normal and emaciated pigs. Furthermore, the relationships between 239 SNPs and immune-related traits were studied. These results demonstrate that identification of genetic components of animal immune systems and susceptibility to infectious diseases is possible and will be useful to improve disease resistance in individuals as well as in breeding programs.

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