• 한국수학교육학회지시리즈A:수학교육
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• 제50권3호
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• pp.285-308
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• 2011

The objective of this study is to review how researches on mathematics education are being conducted currently in Korea and overseas and to examine the current state of domestic researches on mathematics education from a broader view. Although many efforts have been made to understand trends in researches on mathematics education, there have been few in depth studies on research trends in overseas or for comparison between domestic and overseas trends. Thus, this study classified and analyzed 181 domestic articles between 2005 and 2009 in the journals and and 201 overseas articles in the journals and according to year, research area, research contents, school level, research method, and key words using the PME classification system with some modification. Through these analysis, we examined research trends on secondary mathematics education in Korea and overseas. The research findings are as follows. First, 'teaching learning process' was a spotlight area both at home and overseas, and 'realistic mathematics' and 'social cultural subjects' were not covered much either at home or overseas. 'Mathematical communication' occupied a very small portion in Korea but was a highly interesting area in overseas research. Second, research contents of interest were different between Korea and overseas. Research on general area was the mainstream. But geometry and statistics were mainly studied in Korea and algebra and analysis in overseas. Third, research related to middle school was twice more than that related to high school in Korea, But, research related to middle school was the same as high school in overseas. Fourth, qualitative research was the absolute majority both at home and overseas, and philosophical didactical analysis was used only in Korea. Fifth, the order of key words were problem solving - teacher - curriculum - creativity - textbook in Korea, but teacher - teaching - semiotic - affective factor - proo f- problem solving - technology in overseas.

• 한국항해항만학회지
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• 제26권4호
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• pp.465-472
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• 2002

워터프린트는 도심 및 내륙지역과는 다른 독특한 기후특성을 가지고 있으며 이를 고려하지 않고 개발할 경우 시설물의 하자발생, 에너지 및 유지관리비용의 상승을 초래하게 됨은 물론 배후지, 도시기후에 악영향을 미치게 된다. 본 연구는 부산지역의 10개 기상관측지점을 해안선에서 거리에 따라 워터프린트 및 내륙지역으로 분류하고 5년 간의 기상데이터를 이용하여 워터프런트의 기후특성에 대해 검토한다. 또 한 워터프런트 지역임에도 내륙지역과 유사한 기후특성이 나타나고 있는 대연지점을 대상으로 기후특성변화의 원인에 대해 검토한다.

• 한국산업보건학회지
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• 제27권4호
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• pp.333-351
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• 2017

Objectives: This study examines the relationships between indoor radon concentrations and distribution from soil geological mapping in the Hwacheon and Jangsu areas. Methods: GIS and a pivot table were used for inquiries about indoor radon contents, soil characteristics, and geological differences. Results: The Hwacheon area was characterized by the presence of normal and reverse faults as a passage of runoff for radon, sufficient occurrences of minerals containing uranium within granite as a radon source, a high concentration of radon within the granite area and clear differences of radon concentrations between granitic and metamorphic areas. The Jangsu area was characterized by the presence of normal faults, wide distributions of alluvium, and ambiguities on radon concentrations indoors among areas of geological differences. Considering the granite area and alluvium surrounded with granite areas, the characteristics of radon concentrations within soils and indoors in the Jangsu area are similar to those of the Hwacheon area. High concentrations are found with entisol and inceptisol in the Hawcheon area, but with entisol, inceptisol, and ultisol in the Jangsu area. High radon concentrations are found in sandy loam and/or loam. High concentrations are found in recently constructed or brick buildings, but low concentrations in traditional or prefabricated houses showing a high possibility of outward flow. Conclusions: The overall results suggest that radon concentrations in the Hwacheon and Jangsu area are dominantly influenced by geological characteristics with additional artificial influences.

• 한국융합학회논문지
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• 제11권5호
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• pp.209-217
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• 2020

본 연구의 배경은 드론 시장이 거대해짐에 따라 정부는 '드론 촬영 자유구역 지정'을 논의하고 있으나 법 제도 및 절차, 관련 환경요건들이 상충되거나 명확하지 않아 선행되어야 할 요건들을 정립할 필요성이 제기되었다. 연구목적은 촬영 불가지역 범위를 설정하고 자유구역 지정 및 절차에 관한 선결조건을 제시하는 것이다. 연구방법은 문헌연구를 통해 설문서 구성, 인터뷰를 통해 항목 구체화, 전문가 선택 및 참여자 토의를 통해 조건을 제시한다. 연구결과는 항공안전법 등 개정 2개, 자유구역 지정 기준 및 절차 8개, 안내소 운용 등 4개를 도출하였다. 기대효과는 첫째, 드론 촬영을 항공안전법에 포함으로 자유구역 지정에 관하여 국토부와 협의체 구성이 가능하다. 둘째, 촬영금지 영역을 공중까지 확대하여 입체적인 드론 보안이 가능하다. 셋째, 자유구역 지정을 쉽게 적용할 수 있도록 '용인지역 표준모델'을 제시하였다. 향후 연구방향은 드론 촬영 관련 항공안전법 우선 개정과 국가정보원과 연계한 33개 관할지역의 자유구역지정 절차를 준용하여 추진이 필요하다.

• 한국물환경학회지
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• 제39권2호
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• pp.142-152
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• 2023

Infiltration is a process by which precipitation infuses into subsurface soils. The process determines the surface flow and baseflow volume, and it is one of most important hydrological processes regarding nonpoint source pollution management. Therefore, the Ministry of Environment has developed a guideline to determine the impervious area ratio to understand the hydrological process in administrative districts and watersheds. The impervious area ratio can be determined using land use or land cover maps. Three approaches were explored to determine the impervious area ratio in 25 districts in Seoul. The impervious area ratio was determined by employing the Land registration map and Land property data in the first approach, Land property map in the second approach, and Land cover map in the third approach. The ratio ranged from 38.96% to 83.01% in the first approach, 38.98% to 83.02% in the second approach, and 37.62% to 76.63% in the third approach. Although the ranges did not provide any significant differences in the approaches, some districts displayed differences up to 9.48% by the approach. These differences resulted from the fact that the data were land use or land cover, especially in the area of airport, residential complex area, and school sites. In other words, division of the pervious and impervious areas in an individual plot was not allowed in the Land registration map, while it was allowed in the Land cover map. Therefore, it was concluded that there is a need to revise the guideline so that a reasonable impervious area ratio can be determined in the districts.

• 수산해양기술연구
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• 제48권3호
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• pp.208-216
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• 2012

The properties of sediment collected from seabed surface to 6cm depth on the four positions were analyzed to investigate turbulence of marine sediments by shrimp beam trawl. Types of sediments in the investigation area were (g)mS (slightly gravely muddy sand) and gmS (gravely muddy sand) showing high sand content, and (g)sM (slightly gravely sandy mud), gsM (gravely sandy mud) as well. It is estimated that position is more crucial factor than seasonal difference for the granularity variation of sediment in each investigation area. Finding the positional characteristics of sediment granularity was difficult before removing shells and organic matter. However, the average granularity is getting larger by going out from inland sea to open sea once those were removed. The granularity of marine sediment got narrow after processing in the fishing area for shrimp beam trawl but there was no big difference for granularity size before and after processing in the non-fishing area. This might be attributed to crushed shell particles going up and down again on the surface in the fishing area. To demonstrate the hypothesis mentioned above, the sediments driven by shrimp beam trawl need to be collected and analyzed.

• 한국수자원학회논문집
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• 제39권7호
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• pp.583-592
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• 2006

수제설치로 인해 발생되는 세굴공은 수중생물의 다양한 서식처 및 홍수 시 어류의 피난처 제공 등 환경 기능을 내포할 수 있다는 관점이 부각되고 있으며 이와 같은 요구를 충족하기 위해서는 기존의 안정성 문제에 대한 관점에서 벗어난 수제주변 세굴영역에 대한 연구가 필요하다. 생태서식처로의 세굴영역은 수제형태에 따라 다양한 형태가 생성될 수 있으므로 이에 대한 분석이 요구된다. 본 연구는 투과율과 설치각도를 변화한 실험을 통해 수제주변 세굴규모를 파악하여 환경적인 측면의 수제선정의 자료를 제안하는데 목적이 있다. 실험에 적용된 투과율은 불투과(0% 투과)와 투과수제(20%, 40%, 60%, 80%)이며 설치각은 $60^{\circ},\;90^{\circ},\;120^{\circ}$이다. 실험결과, 각 실험조건에 따른 최대세굴 발생시의 세굴영역과 세굴심을 분석할 수 있었으며 수제조건에 대한 차이를 제시하였다.

• Journal of Radiation Protection and Research
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• 제5권1호
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• pp.1-6
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• 1980

A portable count-ratemeter and a thermoluminescent detector ($CaSO_4:Dy$) have been used to obtain total gamma dose rates at approximately 50 locations during the course of several survey trips in the southeastern Korea. The purposes of these measurement were to provide a future reference data and to establish the approximate range of population exposure to the natural environmental radiation. The natural levels encountered ranged from a low of 14.6 microroentgen per hour to a high of 18.9 microroentgen per hour with a mean of $16.3{\pm}1.0$ microroentgen per hour. Among these results are the relatively high natural dose rate levels in the Masan area and Yangsan-Tongdosa area with the relatively low natural dose rate levels in the Gyeongsan-Cheongdo area and the Samrangjin-Jinyeong-Gimhae area.

• Environmental Engineering Research
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• 제12권3호
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• pp.109-117
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• 2007

The characteristics of carbonaceous particles collected from the combustion of Vacuum Residue (VR) in a test furnace have been investigated. The physical and chemical characterization includes particle size, scanning electron microscopy of the surface structure, measurement of porosity, surface area and density, EDX/XRD analyses and measurement of chemical composition. The studies show that the carbonaceous VR particles are very porous and spheroidal, and have many blow-holes on the surface. The particles become smaller and more sponge-like as the reaction proceeds. The present porosity of VR particles is similar to that of cenospheres from the combustion of heavy oil, and the majority of pores are distributed in macro-pores above $0.03\;{\mu}m$ in diameter. Measurements of pore distribution and surface area showed that the macro-pores contributed most to total pore volume, whereas the micro-pores contributed to total surface area.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 제37회 하계학술대회 논문집 A
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• pp.165-166
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• 2006

Recently, after Wide Area Outage of the North-Eastern United States occurred, many countries started to be concerned about WAMS (Wide Area Monitoring System), and Korean power system also experienced Wide Area outage according to typhoon Mae-Mi, and Haenam-Jeju HVDC line fault. Since it is too difficult to detect a symptom based on SCADA or EMS, a defense system of electric power infrastructure has required. In this research, the designed and developed system processes the time synchronized real time power system information based on GPS and shows the 2D/3D monitoring viewer using the phasor data and the results of three algorithms.