• Economic and Environmental Geology
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• v.54 no.5
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• pp.549-560
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• 2021

In 2019, at 147 local governments, a total of 872 operations produced aggregates with 414 operations by permission, 458 operations by declaration except the marine operations. The leading aggregate sources were, in descending order of the number of operations, crushed, forest, land, washing, river aggregate. By aggregate type, gravel-only operations were slightly more than sand-only ones. By province, Gyeongsangbuk-do had 149 operations, followed by Gyeonggi-do with 135, Gangwon-do with 113, and Gyeongsangnam-do with 92, Chungcheongbuk-do with 81, and Jeollabuk-do with 70. A review of production by size of operation indicated that about 23,100 thousand m³ (17.6% of the total aggregate) was produced by 17 operations reporting production of more than 1 million m³, about 29,900 thousand m³ was produced by 44 operations reporting production between 500 and <1,000 thousand m³, about 60,000 thousand m³ was produced by 273 operations reporting production between 100 and <200 thousand m³, about 17,000 thousand m³ was produced by 409 operations reporting production between 10 and <100 thousand m³. 129 operations that producted less than 10 thousand m³ accounted for 0.4% of total aggregate produced in Korea in 2019. Operations that produce more than 1 million m³ of aggregate was only from forest and crushed aggregate. The period of permission for aggregate producing based on permission is mostly less than 10 years, and in particular, for river and land aggregates, the permission period is very short, less than 2 years.

• Journal of Korea Society of Industrial Information Systems
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• v.3 no.1
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• pp.153-164
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• 1998

적응 선채취 캐슁은 시스템 성능 향상을 위한 효율적인 기법이다. 이 논문에서는 객체지향 테이터베이스에서 디스크 참조에 대한 평균 서비스 기간을 감소시키기 새로운 캐슁 기법을 제안한다. 이전에 사용된 방법과는 달리 제안한 방법에서는 과거의 이력을 참조하여 채취 분기점을 탄력적으로 조정함으로써 캐슁의 효율을 향상시킨다. 다양한 질의로 시뮬레이션 한 결과 성능의 우수함을 확인할 수 있었다.

• Water for future
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• v.27 no.3
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• pp.20-24
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• 1994

지하수 자원의 효율적인 이용과 보전을 위하여 필수적인 합리적인 수질감시를 위하여 지하수 수질 감시 사업의 계획수립 방법, 감시정 설치 방법, 지하수 수질 시료채취 방법 및 대수층 시험방법 등에 대하여 간단하게 소개하였으며, 또, 감시정 설치와 시료채취시에 필요한 장비 및 소모품 목록과, 시료 채취 장비의 종류와 특징을 소개하였다. 앞으로 지하수 관련 분야에 종사하는 분들에게 조금이라도 도움이 되었으면 하는 마음이다.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2000.04a
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• pp.311-312
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• 2000

최근 들어 환경대기중 휘발성유기화합물(Volatile Organic Compounds)에 대한 인식이 고조되면서 극미량 유기물질의 채취 및 분석기법에 대한 연구가 활발히 수행되고 있다. 미국의 경우, 1980년대 초부터 대기중 VOC에 대한 연구가 활발히 이루어져서 여러 종류의 VOC에 대한 시료채취 및 분석방법이 명시되어 있지만 우리나라에서는 VOC에 대한 전반적인 측정방법이 아직까지는 없는 실정이다. 미국에서 지정한 VOC의 시료채취방법 중에서 일반적으로 가장 널리 이용되고 있는 방법으로는 용기를 이용하여 유기화합물을 함유하고 있는 공기를 직접 채취하는 방법과 흡착관을 이용하는 방법을 들 수 있다. (중략)

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2012.10a
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• pp.222-224
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• 2012

최근 들어서 우리나라는 각종 육해상 건축물 축조에 필요한 모래골재의 육상공급이 한계에 다다르면서 부족한 골재를 인근해역의 해저에서 채취하여 공급하고 있으며, 이에 따른 해저 골재채취 작업수역을 통항하는 선박들의 안전문제가 크게 대두되고 있다. 이와 관련하여 최근에 태안해역의 흑도/가대암 TSS 부근수역에서의 바다골재 채취를 위한 해상교통안전진단 사업을 수행한 내용을 중심으로 주변수역으로 통항하는 선박들의 통항안전성에 대하여 평가한다.

• Korean Journal of Food Science and Technology
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• v.31 no.1
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• pp.20-23
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• 1999

This study was conducted to investigate the content and composition of tea catechins at different plucking time and different position of tea leaves. The bud and first leaf, second leaf, third leaf, and fourth leaf were collected on May, July, and August. The catechin content was highest in leaves picked on August among those collected from different months. When compared with the different part of tea leaves, the bud and the first tea leaf contained the highest catechin, and the fourth left contained the lowest catechin. Analysis of catechin composition in the tea leaves, showed that epigallocatechin gallate was the highest, and the other contents were following order: epicatechin gallate, epicatechin, epigallocatechin.

• Food Science and Preservation
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• v.24 no.6
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• pp.786-794
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• 2017

This study analyzes the chemical composition and thiobarbituric acid reactive substance levels of Godulbaegi (Youngia sonchifolia M.) depending on collection time. The moisture and crude fat content in leaf and root decreased, while crude fiber, crude protein, carbohydrate, and ash increased with increases in collection time. The mineral elements tended to increase in each sample with increases in collection time. The content of vitamin B increased as collection time increased. Vitamin C content was approximately five times higher in the leaves than that in the roots. Total amino acids in leaf and root increased considerably as collection time increased content of phenolic compounds in root were higher than that in the leaf and these contents increased. Antioxidant activity of Godulbaegi was higher in the root than in the leaf and increased as collection time increased.

• Korean Journal of Soil Science and Fertilizer
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• v.28 no.2
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• pp.183-190
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• 1995

Various factors such as sampling height in the chamber, sampling interval, sampling time at daytime and the effects of pedoturbation on methane emission during chamber installation were evaluated using a simplified closed static chamber method to measure methane flux in paddy soils. Sampling height of the chamber for representative samples was 65cm. An additional DC fan was required to attain an even methane gradient in the chamber. Considering the change of methane concentration and air temperature in the chamber, sampling is recommended to finish within 30 minutes after starting sampling. The aim of setting DC fan in the chamber was to get the thermal equilibrium in the chamber as well as the representative samples. Suitable time to collect the gas samples representing the day's methane flux was 0900~1200 hours. Gas sampling was possible even after installation of small chambers if the elapsed time was more than 6 hours and supporting stand would be to be added to minimize pedoturbation.

• The Korean Journal of Ecology
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• v.27 no.5
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• pp.263-267
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• 2004

The collecting amount of sap by DBH class and contents of mineral and free sugar in the sap of Acer mono in Mt. Jiri were investigated. The total amount of sap throughout the study period was 315 L. Sap of A. mono were increased with increasing DBH, 67 L(21%), 104 L(33%) and 144 L(46%) from small (below 18㎝), middle (20-28㎝) and large (above 30㎝) diameter tree, respectively. This may be due to increase in crown width and extension of root system. Amounts of sap was required by big temperature fluctuation in day and night. The contents of solid, ash and sugar were 1.90%, 0.02% and 1.64% in the sap of A. mono. Free sugar determined in the sap was sucrose with 16.4 g/L, but glucose, fructose and maltose were not detected. The sap of A. mono was composed of seven kinds of mineral. The prominent minerals in the sap were Ca and K and the concentrations were 548㎎/L and 303㎎/L, respectively.

• Proceedings of the Korean Radioactive Waste Society Conference
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• 2009.11a
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• pp.173-174
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• 2009

"방사성폐기물 고화체의 물성시험"에 사용되는 시편을 실험실적으로 제조한 소규모 모의 고화체 시편과 고화공정에서 직접 채취한 소규모 시편, 200L 드럼으로부터 코아시편을 채취 가공하여 만든 시편과 같이 3종류가 있다. 고화공정에서 발생되는 고화체는 일반적으로 200 L 드럼에 주입되며, 고화체의 균일성 정도는 고화공정의 특성, 폐기물/고화매질 혼합비, 200 L 고화체 드럼의 냉각방식에 따라 다르다. 따라서, 실험실에서 제조한 시편과 공정에서 채취한 소규모 시편을 실제 고화공정을 대표할 수 없으며 또한 실제 발생된 고화체의 조성과도 동일하다고 볼 수 없다. 따라서 200 L 실드럼에서부터 코아시편을 채취하여 만든 시편이 고화공정과도 고화체를 대표할 수 있는 시편으로 볼 수 있다. 기 발생고화체(시멘트와 파리핀 고화체 및 잡고체 폐기물)의 영구처분을 위하여 과기부 고시 05-18호 "폐기물 인도기준" 규정과 한국방사성폐기물관리공단의 중 저준위 방사성폐기물 인수기주(안)의 준수 여부를 평가하기 위하여 각 원전의 대표 드럼에 대하여 특성평가시험인 압축강도, 침출, 침수, 열 순환, 내방사성 영향시험을 수행하기위해 실 드럼으로부터 원통형 코아시편을 채취하여 이를 시험검사에 필요한 시험시편으로 가공한 후 표준 특성시험법을 이용하여 물성들을 평가하며 특성평가시험을 위한 시편으로는 L/D=2, L/D=1인 두 종류의 시편을 가공하였으며 압축, 침수, 열순환 및 방사선조사시편은 L/D=2 시편을 제조하였고 침출시험시편은 L/D=1인 시편을 채취하였다.