• 한국통신학회논문지
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• 제37권6A호
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• pp.426-437
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• 2012

This paper proposes an array antenna assisted Doppler spread compensator with dummy elements which are placed on either end of a monopole array for a digital terrestrial television broadcasting (DTTB) receiver. An array antenna assisted Doppler spread compensator, proposed previously, has a major drawback in performance degradation owing to mutual coupling effect among array elements. In order to solve the mutual coupling problem, dummy elements, placed on both sides of the monopole array mitigate performance degradation of a Doppler spread compensator arising from the mutual coupling among monopole array elements. Computer simulation results show that the dummy elements can reduce this performance degradation as well as expand the operating bandwidth of a Doppler spread compensator.

• 대한지구과학교육학회지
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• 제10권3호
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• pp.235-253
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• 2017

본 연구의 목적은 최근 20년간 국내외 문헌에 나타난 지질 답사 교육 사례가 야외 지질학 탐구 요소를 어떻게 반영하고 있는지 교육 대상별로 비교 분석하는 것이다. 분석 대상 사례는 총 53건이며, 분석은 야외 지질학 탐구 요소 및 하위 요소에 대해 수행되었다. 분석 결과, 야외 지질학 탐구 요소 반영양상에서 초중고생 대상 지질 답사 교육 사례와 지질학 관련 전공생 대상 사례 간 명확한 차이가 드러났다. 초중고생 대상 답사는 주로 교육 과정에 기반하여 설계되었기 때문에 야외 지질학 탐구 요소 중 관찰, 표상, 귀추적 추론 중 2~3가지를 포함하는 경우가 많았다. 반면 지질학 관련 전공생 대상 답사는 지질 전문가 양성을 목적으로 하기 때문에 야외 지질학 탐구 요소 중 4~5개를 다양하게 포함하고 있으며 공간적 사고 및 통시적 사고의 비율도 높게 나타났고, 지질도 작성 등 전문 기술을 요구하는 활동이 자주 활용되었다. 과학 교사 대상 답사는 초중고생 및 지질학 관련 전공생 대상 답사의 특징이 혼합된 형태로 나타났다. 포함된 탐구 요소의 다양성, 지질학자가 수행하는 활동과의 유사성, 학습자의 자율성 등을 종합적으로 고려했을 때 지질학 관련 전공생 대상 답사가 다른 교육 대상의 답사보다 야외 지질학 탐구의 실제성이 높은 것으로 평가되었다. 이 연구의 결과를 바탕으로 참 과학 탐구로서 지질 답사교육의 활용을 위한 시사점을 제시했다.

• 한국지하수토양환경학회지:지하수토양환경
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• 제16권4호
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• pp.53-61
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• 2011

This study examined evaluation on stabilization of major and trace elements in tailings by various surface water-preventing materials. Six columns were filled with tailings of the Sinlim mine, then covered with tailings only, compacted soils, clay, soil-bentonite mixture, pozzolan and bentonite mat. After injection of artificial rain water, the leachate was sampled with times (3, 6, 9 and 12 pore volume) and analysed for major (Ca, Na, Mg, K) and trace elements (As, Cd, Cu, Pb, Zn) by ICP-AES. With exception to pozzolan type, the pH values of leachate from the other types became stabilized from 5.5 to 7.5, and EC (electric conductivity) of leachate from them decreased with times. For the pozzolan type, however, the pH and EC of leachate increased with time due to its alkalinity producing system. Concentrations of most major and trace elements in leachate decreased and stabilized with time. Consequently, soil-bentonite mixed cover shows the best ability of water-preventing and reducing mobility of elements in tailings site.

• 자원환경지질
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• 제27권4호
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• pp.363-373
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• 1994

The Cretaceous granitic rocks show differences in rock types and chemical compositions according to metallogenic provinces of copper, lead zinc and molybdenum in the Gyeongsang basin. Jindong granites are of granodiorite~quartz diorite~diorite in Cu-province; Makeunsan/Yucheon-Eonyang granites, granodiorite~granite in Pb Zn-province; Onjeongri-Yeonghae granites, granodiorite~quartz diorite in Mo-province, and there is a trend that productive masses are less differenciated than barren masses in Cu and Pb-Zn provinces whereas productive masses are more differenciated than barren masses in Mo province. Metallogenic provinces are distinguishable by variations of major and trace elements. The Cretaceous granitic rocks are highest in the content of Ca, Mg and other basic major elements and lowest in the content of K and Na in Cu provicne; the variation trends are vice versa in Pb-Zn province. Trace elements such as Rb and Sr show variations related to K and Ca, and metallogenic provinces are also distinguishable by their ratios. The granitic rocks of Mo province have intermediate content of major and trace elements, but are clearly distinguishable from Jindong granites and partly overlapped by Yucheon-Eonyang granites. Chlorine content in biotites is higher in a productive mass than in a barren mass in Cu province. Therefore, the mineralogical and chemical compositions are applicable as geochemical index to distinguish the types of mineralizaion, and productive and barren masses of the Cretaceous granitic rocks in the Gyeongsang basin.

• 정보관리학회지
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• 제37권1호
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• pp.23-49
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• 2020

본 연구는 문헌정보학 정규교육과정에서 중점적으로 다뤄야 하는 정보조직분야의 주요 영역을 도출하고, 영역별 내용요소를 제안하였다. 이를 위해 문헌연구, 내용분석, 설문조사 및 전문가평가를 수행하였다. 이를 통해 정보조직분야를 정보조직일반, 분류, 목록, 실습이라는 4영역으로 구성하고, 총 31개의 영역별 내용요소를 제시하였다. 본 연구를 통해 영역별로 도출된 내용요소들은 정보조직분야 교과목에 대한 강의계획안이나 교수 요목을 설계할 때 도움이 될 수 있는 기초자료로 활용할 수 있다. 또한, 본 연구에서 사용한 연구방법을 적용하여 정보조직분야의 주요 영역별 내용요소를 확장할 수 있기 때문에, 정보조직분야 교육내용을 설계를 위한 기초자료로 활용될 수 있을 것이다.

• 한국기후변화학회지
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• 제9권4호
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• pp.471-485
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• 2018

The Republic of Korea (ROK) has made many efforts to reduce greenhouse gases through a legal framework, making obligations to reach domestic and overseas targets via the Paris Convention in 2015. China recently launched a nation-wide emission trading system (ETS) and has considered extending this ETS to include the ROK. This study examines the possibility of linking the ETS between ROK and China by considering the institutional design elements of the ETS. Additionally, this study provides policy implications to reach Korea's overseas reduction target. For the research methodology, the design elements of both the ROK and China policies were analyzed by categorizing their standard design elements based on the International Carbon Action Partnership. This paper focuses on four main barriers (cap type, borrowing, offset and price ceiling) based on their environmental benefits and analyzes the challenges to combining the design elements between the ROK and China systems. The two ETS commonly share the same cap types, and there is similar institutional progress regarding the offset and price ceiling. In addition to this, note that China has a borrowing system that is opposite to the borrowing system in ROK. According to these findings, there are major challenges to linking the ROK and China systems due to differences in the major design elements. Thus, it is necessary to modify the Korean domestic borrowing system and understand the Chinese institutional processes related to environmental negotiation to achieve further cooperation.

• 원자력산업
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• 제6권5호통권39호
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• pp.23-27
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• 1986

• 자원환경지질
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• 제33권6호
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• pp.447-467
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• 2000

This study was carried out geochemically and mineralogically to define how Kunsan shore sediments are related to their terrestrial source rocks in the region of Keum River Basin, western Korea. As a whole the chemical composition for major elements, trace elements and rare earth elements analysis from shore sediments and river bed sediments doesn't show the big difference, and especially rare earth elements chondrite normalized patterns are almost same. Heavy minerals of shore sediments are identified as hornblende, epidote, ilmenite, garnet, hematite, magnetite, sphene and rutile. Compared with Taean Area of Seo et al. (1998) and Byeonsan Area of Kwon et al. (1999), Kunsan shore sediments of this study area were origined mostly from Keum River Basin.

• Environmental Engineering Research
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• 제21권3호
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• pp.247-255
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• 2016

Ten trace elements (Mg, Ca, V, Cr, Mn, Fe, Cu, Zn, Mo, and Cd) were determined in seven traditionally used wild medicinal plants of the Nagas in the North-East India viz Cynoglossum furcatum Wallich, Elsholtzia blanda Bentham, Lycopodium cernuum Linnaeus, Potentilla fulgens Wallich ex Hooker, Swertia macrosperma C.B. Clarke, Thalictrum foliolosum DC and Valeriana jatamansi Jones. Plant samples were dried, weighed, digested and analyzed for their mineral distribution level ranging from trace to major elements by graphite furnace-atomic absorption spectroscopy. All the medicinal herbs studied were found to contain the ten elements analyzed. The elemental concentration is given in mg/kg. Mg and Ca are present in high concentrations in both the roots and leaves of the plant samples. Among trace transition metals Fe had the highest concentration, followed by Mn, Cr, Cu, V, Zn, and Mo. Analysis showed that the toxic Cd element was at a lower concentration and is within the permissible limit of FAO/WHO, California standards and United States Pharmacopeia Limit for Nutritional Supplements.

• Journal of Astronomy and Space Sciences
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• 제6권2호
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• pp.91-100
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• 1989

정지 위성 궤도의 평균 궤도 요소를 비 특이점 궤도 요소 항으로 연구하였다. 실제 위성의 위치는 평균 궤도로부터 단주기 섭동 만큼 위성 위치가 진동하는데, 그 진동의 진폭은 1800m 이하이다. $e_c$ 와 $e_s$의 평균값도 얻었다.