• The Journal of Korean Institute of Communications and Information Sciences
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• v.37 no.6A
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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.

• Journal of the Korean Society of Earth Science Education
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• v.10 no.3
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• pp.235-253
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• 2017

The purpose of this study is to compare by learner groups(K-12, geology-related majoring students, science teachers) how geologic fieldwork education cases in domestic and foreign papers for recent 20 years reflect the elements of inquiry in field geology. The total number of analyzed cases is 53(58 for double counting), and the analysis was conducted on the elements of inquiry in field geology and their sub-element. As a result, there was a clear difference between the cases of geologic fieldwork education for K-12 and college students majoring in geology-related disciplines, in the way of reflecting elements of inquiry in field geology. Because most of K-12 target fieldworks were designed based on the curriculum, it mainly included 2-3 elements of observations, representations, and/or abductive reasoning. On the other hand, because fieldworks for geology-related major students aim to train geologic experts, it diversely contained four or five of the elements of inquiry in field geology, including spatial thinking and diachronic thinking in a high proportion, and also frequently used activities that require specialized skills such as geological mapping. Fieldworks for science teachers were found to have mixed features of K-12 and geology-related major students. Considering the diversity of included inquiry elements, similarities with the activities performed by geologists, and the autonomy of learners, it was analyzed that geologic fieldwork for geology-related major students was more close to authentic geologic inquiry than fieldwork for others. Based on the results of this study, we suggested implications for improving geological fieldwork as authentic science inquiry.

• Journal of Soil and Groundwater Environment
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• v.16 no.4
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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.

• Economic and Environmental Geology
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• v.27 no.4
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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.

• Journal of the Korean Society for information Management
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• v.37 no.1
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• pp.23-49
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• 2020

This study derives the main areas of information organization that should be covered in the formal curriculum of Library and Information Science, and suggests content elements for each area. Literature research, content analysis, survey and expert evaluation were conducted. Based upon these, information organization field was composed of four areas: information organization in general, classification, inventory, and practice, and a total of 31 content elements were presented. The content elements derived from each area through this study can be used as basic and helpful data when designing syllabus or teaching subjects in the field. In addition, it is possible to expand the content elements of each area of the information organization field through the research method used in this study. Finally, the results of this study will be used as basic materials when conducting the educational contents of information organization field.

• Journal of Climate Change Research
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• v.9 no.4
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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.

• Nuclear industry
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• v.6 no.5 s.39
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• pp.23-27
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• 1986

• Economic and Environmental Geology
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• v.33 no.6
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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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• v.21 no.3
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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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• v.6 no.2
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• pp.91-100
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• 1989

The mean orbital elements for geosynchronou8s satellite are developed in terms of non-singular orbital elements. The true satellite position oscillates about the position calculated from the mean elements due to short period perturbations to the satellite motion. The displacement of a geostationary satellite from this mean orbit position is less than 1800m. The mean elements of ec are obtained.