• Journal of the Mineralogical Society of Korea
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• v.13 no.3
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• pp.115-120
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• 2000

Oxidation of pyrite has caused a serious environmental problem such as the acidification of soil and surface water. The mineralogical change of acid sulfate weathering of hydrothermally altered andesite which contained 11.8% of pyrite and was exposed in atmosphere by lay out works for a residential area and a golf course was studied using X-ray diffraction (XRD) and electronmicroscopes. Ferrihydrite, jarosite, and an unidentified water soluble phase were observed as weathering products of the andesite. Under electronmicroscopes, showed aggregate of platy microcrystals; jarosite was platy morphology: water soluble Phase was columnar. Morphology of fresh Pyrite in the andesite changed from pyritrohedron to cubic in its frequency with increasing its particle size. The drainage water was acidic (pH 3.5) and in an equilibrium state with both ferrihydrite and jarosite.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.41 no.5
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• pp.512-519
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• 2016

This paper presents spectrum utilization strategies in cognitive radio (CR) networks powered by multi-antenna based wireless energy transfer. Secondary access point (AP) with multiple antennas should transfer the energy to the secondary sensor nodes with energy beamforming and simultaneously induces no interference to PUs. In addition, sensor nodes can transmit information to the secondary AP using the harvested energy, only when the spectrum is not utilized by PUs. We analyze the achievable rate of the CR sensor networks and propose an interference nulling energy beamforming method to maximize the achievable rate. Finally, we also propose a frame scheduling algorithm in which the durations of wireless energy transfer/information transfer frames (phases) are optimized.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.32 no.3
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• pp.294-301
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• 1987

This experiment was carried out to investigate the occurrence of tiller and its proportion to grain yield under 5 different plant densities. Plant density 5 x 5cm was more favorable for increasing the number of spikes per unit area, where leads to improve grain yield. Effective tillers showed only main stem, M$_1$-axil and M$_2$-axil, indication more effective tillers in M$_1$ rather than main stem. Every tillers held at least 6 leaves to bear spikes, indicating that main stem has 12 -13 leaves. Leaves attached on main stem M$\sub$0/ and M$_1$ were very important as main source of photosynthesis, especially under more compart plant densities while leaves of M$_1$ occupied 66.8% in a plant. The proportion of grain yield of each tiller to total grain yield per plant was high in main stem under conpact plant density, in M$_1$ stems under less compact plant density, and in M$_2$ -stems under wide plant density, indicating same result on multiple regression analysis.

• Journal of the Korean Electrochemical Society
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• v.14 no.3
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• pp.157-162
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• 2011

The stability at elevated temperatures of a surface film formed on a graphite electrode in lithium secondary batteries was investigated by transmission electron microscopy (TEM) and electrochemical AC impedance spectroscopy (EIS). TEM analysis revealed that the surface film partly dissolved in the electrolyte solution during storage at $60^{\circ}C$, resulting in a decrease in the thickness of the surface film and a change in its morphology to a porous structure. On the other hand, an increase in the impedance of the surface film which is attributable to a change in composition of the surface film was confirmed by EIS analysis during the storage at $60^{\circ}C$. It was also shown that the addition of vinylene carbonate or 1,3-propane sultone or etylene sulfite, even if limited, improves the stability of the surface film at elevated temperatures.

• The Mathematical Education
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• v.57 no.3
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• pp.231-246
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• 2018

In this paper, we applied Sfard's reification theory to analyze the secondary students' level of conceptualization with regard to the formula of quadratic equation. Through the generation and development of mathematical concepts from a historical perspective, Sfard classified the formulation process into three stages of interiorization, condensation, and reification, and proposed levels of formulation. Based on this theory, we constructed a test tool reflecting the reversibility of the nature of manipulation of Piaget's theory as a criterion of content judgement in order to grasp students' conceptualization level of the formula of quadratic equation. By applying this tool, we analyzed the conceptualization level of the formula of quadratic equation of the $9^{th}$ and $10^{th}$ graders. The main results are as follows. First, approximately 45% of $9^{th}$ graders can not memorize the formula of quadratic equation, or even if they memorize, they do not have the ability of accurate calculation to apply for it. Second, high school curriculum requires for students to use the formula of the quadratic equation, but about 60% of $10^{th}$ graders have not reached at the level of reification that they can use the formula of quadratic equation. Third, as a result of imaginarily correcting the error of the previous concept, there was a change in the levels of $9^{th}$ graders, and there was no change in $10^{th}$ graders.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.4
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• pp.2704-2712
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• 2015

This study was the secondary analysis using the Korea National Health and Nutrition Examination Survey of 2012 and purpose was to investigate the effects of menopause on the metabolic syndrome(MetS) in Korean women. In raw data, total 2,746 women aged ${\geq}19$ years and provided the correct data about menstruation and menopause were analysed. The results were as follows: First, components of MetS were significantly different according to menopausal status. Second, the prevalence of MetS was 13.2% in premenopausal women and 42.7% in postmenopausal women. Third, the Odds ratio of postmenopausal women was 4.88(95% CI=3.888-6.126) compared with premenopausal women for MetS. As 5 years from 40 years increased, the Odds ratios of postmenopausal women were 3.15(95% Confidence Interval=1.862-5.331), 4.159(2.558-6.761), 5.971(3.955-9.016), 9.52(6.591-13.749) compared with premenopausal women for MetS, respectively. Based on the results, the intervention should be developed and provided for preventing and managing the MetS in postmenopausal women.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.16 no.11
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• pp.2453-2458
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• 2012

In this paper, we propose an adaptive thresholding method to binarize two-dimensional barcode images. Adaptive thresholding methods that minimize light effects convert an original image into a binary image. The methods are applied to document image binarization. The methods, however, have problems of determining box size used in adaptive thresholding. thus, they inappropriate to use in recognition of two-dimensional barcode images. To overcome the problem, we analysis the problem and propose a new adaptive threshold method using the integral image. To show the effectiveness of our method, we compared our method with the well-known existing methods in terms of visual quality and processing time. The experimental result indicates that the proposed method is superior to the existing method.

• Journal of the Korean Society for Marine Environment & Energy
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• v.10 no.3
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• pp.173-180
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• 2007

Oscillating wave amplitude in a bottom-mounted OWC chamber designed for wave energy converter is investigated by applying characteristic wave conditions in Korean coastal water. The effects of shape parameters of OWC chamber in a view of wave energy absorbing capability are analyzed. Both experimental and numerical approaches are adopted and their results are compared to optimize the shape parameters which can result in a maximum power production under given wave distribution. The experiment was carried out in a wave flume under 2-D assumption of OWC chamber. The numerical scheme employed a hybrid Green integral equation which adopts the Rankine Green function inside chamber to take account of fluctuating air pressure, while it uses the Kelvin Green function in outer domain. Air duct diameter, chamber width, and submerged depths of front skirt and back wall of chamber changes the magnitude and peak frequency of wave absorption significantly.

• Journal of Korean Medical classics
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• v.13 no.1
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• pp.253-268
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• 2000

1613년허준소간적(年許浚所刊的)${\ll}$동의보감(東醫寶鑑)${\gg}$불지시의사학종사자적연구과제(不只是醫史學從事者的硏究課題). 인위(因爲)${\ll}$동의보감(東醫寶鑑)${\gg}$병불시단순적의서(?不是單純的醫書), 이차서구유료도가내단사상급역학사상등철학사고지고(而此書具有了道家內丹思想及易學思想等哲學思考之故). ${\ll}$동의보감(東醫寶鑑)${\gg}$소출간적나시대수연성리학점굴료수위(所出刊的那時代雖然性理學占掘了首位), 단시차서소구적도교색채비임하의서갱농후(但是此書所具的道敎色彩比任何醫書更濃厚). 내경편적체계시피(內景篇的體系是被)${\ll}$황정경(黃庭經)${\gg}$영향적(影響的). 작위수련서(作爲修鍊書), ${\ll}$황정경(黃庭經)${\gg}$시도교주요경전지일是道敎主要經典之一). 비서인위인체즉시신적세계(比書認爲人體卽是神的世界), 인체적각기관우시저사신소주적안댁(人體的各器官又是這些神所住的安宅). 내경편이차(內景篇以此)${\ll}$황정경(黃庭經)${\gg}$위자爲資), 구성료기본체계급기주요내용(構成了基本體系及其主要內容). 우기시(尤其是), 내경편접수도가역학사상이설명천인상응(內景篇接受道家易學思想而說明天人相應). 즉(卽), 내경편접수(內景篇接受)${\ll}$참동계(參同契)${\gg}$주급(注及)${\ll}$회남자(淮南子)${\gg}$등도교문헌리소재적(等道敎文獻裏所載的)'발생론(發生論)', 인이음양오행적정기래해설만물여인지상응관계(因而陰陽五行的精氣來解說萬物與人之相應關係). 차정기계승위내단사상적정기신론(此精氣繼承爲內丹思想的精氣神論). 정여기(精與氣), 기여신(氣與神), 신여정시재우불단지호상접촉호상융화적관계상(神與精是在于不斷地互相接觸互相融化的關係上). 필자인위내경편이정기신론위주(筆者認爲內景篇以精氣神論爲主), 장의서인진료도교수련적경계(將醫書引進了道敎修鍊的境界). 단시(但是), 본론문불지간분석연구내경편소인적(本論文不至干分析硏究內景篇所引的)${\ll}$황제내경(黃帝內經)${\gg}$등의서포함적도교관(等醫書包含的道敎觀). 요시리해(要是理解)${\ll}$동의보감(東醫寶鑑)${\gg}$소인의서적사상기원급기내용(所引醫書的思想起源及其內容), 대연구내경편급(對硏究內景篇及)${\ll}$동의보감(東醫寶鑑)${\gg}$전편적철학성취유흔대적방조(全篇的哲學性就有?大的幇助). 차시필자요계속요연구적과제파료(此是筆者要繼續要硏究的課題擺了).

• Journal of Life Science
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• v.25 no.6
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• pp.615-623
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• 2015

This study investigated the effects of dissolved cement powder on Zacco koreanus by analyzing morphophysiological changes. The gills exposed to dissolved cement powder developed abnormal shapes in their secondary lamellae and increased numbers of mucous cells after long-term exposure. Additionally, clubbing, edema, and exfoliation of the epithelial cells were observed in the secondary lamellae. In the kidney tissue, the space in Bowman’s capsule was widened, and in the integument tissue the arrangement of the dermis was irregular due to the thinned epidermis. These results suggest that long-term exposure to cement powder can significantly affect morphological change, resulting death. The activities of antioxidant enzymes and LDH tended to increase commensurately with the duration of cement exposure. It was concluded that up-regulated proteins were the stress proteins involved in myofibrillar-protein production and down-regulated proteins were involved in glycolysis and energy metabolism after the integument’s exposure to cement. According to these results dissolved cement powder is a serious threat to the survival of fish because it causes morphological changes and weakens physiological activity in Z. koreanus tissues.