• 한국과학교육학회지
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• 제22권3호
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• pp.432-443
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• 2002

본 연구는 제 7차 교육과정에 따른 7학년 과학 교과서 생물 및 물질 영역에 제시된 과학 개념을 구체적 개념 수준과 형식적 개념 수준으로 나누어 비교 분석 하였다. 분석 교과서는 검정되어 현재 학교에서 사용되고 있는 6종을 대상으로 하였으며, 생명 영역의 '생물의 구성', '소화와 순환', '호흡과 배설', 물질 영역의 '물질의 세 가지 상태', '분자의 운동', '상태변화와 에너지' 단원 등 총 6개 단원의 과학 개념을 분석하였다. 7학년 과학교과서에 제시된 총 개념의 수는 생명 영역에서 305개, 물질 영역이 73개로 물질 영역 보다 생명에서 훨씬 많은 개념이 제시된 것으로 조사되었다. 교과서별로는 제시된 개념의 수가 다소 차이를 보였는데, 생명 역역에서는 179${\sim}$201개, 물질 영역은 33${\sim}$39개로 나타났다. 각 영역별로 구체적 개념과 형식적 개념의 비율을 살펴보면, 생명 영역은 각각 58%, 42%, 물질 영역은 각가 14%, 86%로 영역에 따라 극명한 차이를 나타내는 것으로 조사되었다. 이는 교육과정 및 교과서 개발 시 학습자의 인지 수준을 고려한 과학 개념의 제시 또는 교과 영역의 특서엥 따라 단원 구성에 있어서 차별화 해야함을 시사한다고 하겠다.

• 대한환경공학회지
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• 제27권7호
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• pp.753-761
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• 2005

전처리 공정에 따른 투과 flux 변화를 살펴보면 $MIEX^{(R)}$+UF 공정의 경우 응집+UF 공정에 비하여 높은 유기물 제거율을 나타내었으나 투과 flux 감소는 크게 나타났다. 따라서, 막 오염을 자세하게 규명하기 위하여 sequential filtration 실험결과 막 오염물질은 고분자 유기물질로 나타났으며, DOC 0.5 mg/L 이하의 유기물질이 막 오염 유발물질로 작용하고 있었다. 10 kDa 이하의 저분자 유기물질들은 $MIEX^{(R)}$ 처리에 의해 제거가 용이하여 막 표면에서 유기물 부하를 감소시켜 이로 인해 응집+UF공정에 비하여 투과 flux 감소율이 낮게 나타났다. $MIEX^{(R)}$+UF공정은 입자상 물질의 존재 유무에 관계없이 flux 감소율은 거의 유사한 경향을 보였으나 응집+UF공정은 용존성 유기물질만이 존재하는 시수에 비하여 입자상 물질이 존재하는 경우에 투과 flux 감소가 더 낮게 나타났다.

• 한국토양비료학회지
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• 제31권4호
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• pp.414-419
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• 1998

우리나라 논 밭 경작지 토양의 표면전하에 미치는 유기물의 기여도를 파악하기 위하여, 화강암 풍화토(사촌통, 상주통)와 석회암 풍화토(율곡통, 평전통)를 가지고, 유기물 제거 전후 토양의 표면전화 특성을 이온흡착법을 이용하여 pH 3.5~9.0 범위에서 측정하였다. 유기물 제거 여부에 관계없이 모든 토양의 표면 음전하는 실험 pH 범위 내에서 pH 증가에 따라 직선적으로 증가하였다. pH 다누이 변화량에 대한 토양 표면 음전하의 단위 변화량(dCEC/dpH)을 토양 표면전하의 pH 의존성 지표로 제안하였다. 유기물 제거후에는 0.16~1.91의 범위로 크게 낮아졌다. 자연 토양 pH 조건에서 전체 토양표면전하량 중 유기물에 의한 표면전하량의 비율은 15.0~82.4% 범위로 나타났다. 토양유기물 1%가 발현하는 토양표면전하량은 $0.22{\sim}5.03cmol^+\;kg^{-1}$로 토양별로 차이가 컸다. 토양 유기물이 dCEC/dpH에 미치는 영향은 oxalic acid 추출 산화철 함량이 많은 논토양이 밭토양에 비하여 작았다.

• 한국환경복원기술학회지
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• 제25권4호
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• pp.15-31
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• 2022

The Green Purification Unit System (GPUS) is a green infrastructure facility applicable to the roadside to reduce particulate matter from road traffic. This study introduces two types of GPUS (type1 and type2) and assesses the performance and maintenance costs of each of them. The GPUS's performance analysis used the data collected in November 2021 after the installation of the GPUS type1 and type2 at the study site in Suwon. The changes in the particulate matter concentration near the GPUS were measured. The maintenance cost of GPUS type1 and type2 was assessed by calculating the initial installation cost and the management and repair cost after installation. The results of the performance analysis showed that the GPUS type1, which was manufactured by combining plants and electric dust collectors, had a superior particulate matter reduction performance. In particular, type1 produced a greater effect of particulate matter reduction in the time with a high concentration (50㎍/m³ or higher) of particulate matter due to the operation of electric dust collectors. GPUS type2, which was designed in the form of a plant wall without applying an electric dust collector, showed lower reduction performance than type1 but showed sufficiently improved performance compared to the existing band green area. Meanwhile, the GPUS type1 had three times higher costs for the initial installation than GPUS type2. In terms of costs for managing and repairing, it was evaluated that type1 would be slightly more costly than type2. Finally, this study discussed the applicability of two types of GPUS based on the result of the analysis of their particulate matter performance and maintenance cost at the same time. Since GPUS type2 has a cheaper cost than type1, it could be more economical. However, in the area suffering a high concentration of particulate matter, GPUS type1 would be more effective than type2. Therefore, the choice of GPUS types should rely on the status of particulate matter concentration in the area where GPUS is being installed.

• 한국지반공학회논문집
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• 제24권9호
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• pp.13-21
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• 2008

분배성 추적자 시험법은 LNAPLs(light nonaqueous phase liquids)로 오염된 지반을 조사하는데 아주 유용한 방법이다. 하지만 토양 내 유기물질로 흡착되는 분배성 추적자는 잠재적으로 분배성 추적자 시험법의 정확성에 영향을 끼칠 수 있다. 연구 결과, 추적자의 액상-LNAPL 간 분배 계수는 선형 관계를 보였다. 토양의 흠착능력을 평가하기 위해 흡착 등은 실험을 수행한 결과, Freundlich 흡착 등은 양상과 거의 일치하였고, 추적자의 흡착 정도는 토양 내 유기물질 함량이 증가함에 따라 증가하였다. 또한, 토양 유기물의 흡착능에 따른 잠재적 영향을 판단하고, 추적자 시험법에 의한 LNAPLs 예측의 오차를 수정하기 위해 서로 다른 유기물 함량을 가진 4개의 컬럼 실험을 수행하였다. 컬럼 실험 결과, 오염물질이 없더라도 주문진 표준사와 유기물질이 섞인 컬럼에서는 추적자의 분리 현상이 발생하였다. 오염물질로 케로진을 주입한 이후에 다시 추적자 시험법을 수행하여 파괴곡선을 구한 결과, 토양 유기물질에 대한 추적자의 흡착으로 인해 추적자의 지연계수(R)가 커졌고 LNAPLs의 오염도가 과대평가 되었다. 또한 컬럼 실험 결과를 바탕으로 유기물 함량과 LNAPLs의 예측도 사이의 관계식을 제안하였다.

• 한국멀티미디어학회논문지
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• 제20권8호
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• pp.1208-1215
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• 2017

Recently, people's attention and worries about fine particulate matter have been increasing. Due to the construction and maintenance costs, there are insufficient air quality monitoring stations. As a result, people have limited information about the concentration of fine particulate matter, depending on the location. Studies have been undertaken to estimate the fine particle concentrations in areas without a measurement station. Yet there are limitations in that the estimate cannot take account of other factors that affect the concentration of fine particle. In order to solve these problems, we propose a framework for estimating the concentration of fine particulate matter of a specific area using meteorological data and traffic data. Since there are more grids without a monitor station than grids with a monitor station, we used a domain adversarial neural network based on the domain adaptation method. The features extracted from meteorological data and traffic data are learned in the network, and the air quality index of the corresponding area is then predicted by the generated model. Experimental results demonstrate that the proposed method performs better as the number of source data increases than the method using conditional random fields.

• 한국초등과학교육학회지:초등과학교육
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• 제37권2호
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• pp.147-160
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• 2018

The purpose of this study is to compare the elementary science curriculum and textbooks of Korea, the United States, Japan, and Singapore to know how the contents on particulate concept of matter is introduced and expressed. In Korea, particulate concept of matter was adopted as a term for 'molecules' in the 3rd through 6th curriculum, and the term for 'particles' was adopted in the 2009 revised curriculum. In the United States, NGSS adopted the term 'particle' in fifth grade. Japan presented the concept of 'particle' as a core concept of matter in the commentary, and the expressions 'particles' were being introduced in the textbooks. But it did not cover particulate nature of matter at the elementary school level in Singapore. An analysis of elementary textbooks in Korea, the United States and Japan except Singapore showed particulate expressions in 'dissolution', 'state change of water', 'gas pressure and volume', 'combustion and extinguishment' units. Korean textbook was only being introduced in 'dissolution' and 'gas pressure and volume', but in the textbooks of Japan and the United States, water was expressed as particles in 'state change of water' unit. Discussion and implication on the introduction of particulate concept to elementary science curriculum and textbooks were suggested based on the results.

• 대한지리학회지
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• 제39권1호
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• pp.132-152
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• 2004

The critical point in this research is that the research on the phenomenon "teaching geography" should include how various elements consisting of the phenomenon are interrelated with each other in diverse angles, not deal with only teaching methods. This research focused on the relationships of the three components of teaching geography : contents of geography subject matter; learner; and scaffolding. Firstly, the characteristics of contents of geography subject matter were analyzed. Geographical knowledge was classified into four categories based on the way of perception. And then the selected geographic contents for this study were done didactic transposition into materials for geography education. These can be presented in a specific classification system from a context of geography education. Secondly, four categories of learning styles were divided by the way learners perceive and process information : Diverger; Assimilator; Converger; Accommodator. Each was connected with learner′s preferred contents of geography subject matter. The correlation between divergers and typical CulturalㆍHistorical Geography and Environmental Geography was high. So was between assimilators and typical Physical Geography and UrbanㆍEconomic Geography. Learners of Converger style tend to prefer GIS and Cartography. Finally, Regional Development and Regional Environmental Problems were highly correlated with accommodators.

• 한국초지조사료학회지
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• 제20권3호
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• pp.193-198
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• 2000

Plant characteristics of four winter crop hairy vetch, red clover, crimson clover and rye as green manure were evaluated at three harvesting time(Apri1 23, May 9, May 28) in spring to select superior winter green manure crop. Rye and hairy vetch had superior wintering ability and produced high dry matter compared with crimson clover and red clover. But N amount of rye was small because of its low plant N% despite of early dry matter accumulation. Wintering ability of crimson clover was very poor, so its dry matter decreased rapidly with low seeding rate. Hairy vetch had high N % (4%, C:N ratio 11) and produced high N yield among four plant. It is estimated that hairy vetch have high N-fixing ability because its N% was not changed largely despite of dry matter accumulation at late harvesting time contrast to the other legume. It was thought that hairy vetch was superior green manure crop in considering yield of dry matter and N. (Key words : Winter legumes, Hairy vetch, Green manure yield, Nitrogen concentration)

• 무역상무연구
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• 제19권
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• pp.169-190
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• 2003

Uniform Computer Information Transactions Act (UCITA) for e-commerce in non-UCC and non-UETA transactions, promulgated in 1999. The Act Drafted by the National Conference of Commissioners on Uniform State Laws. UCITA applies to contracts to license or buy software, contracts to create computer programs, contracts for on-line access to databases and contracts to distribute information over the Internet. UCITA does not apply to goods such as television sets, stereo equipment, airplanes or traditional books and publications. Goods generally remain subject to UCC Article 2 or Article 2A. Many transactions may include more than computer information. If that transaction covers non-goods subject matter, UCITA applies only to the part of the transaction which is computer information and other law applies to the other subject matter. In the event the other subject matter is goods, UCC Article 2 or 2A applies to the goods subject matter and UCITA applies to the computer information part. UCITA is coordinated with existing Articles 2 and 2A, so coverage of each to part of the transaction will be facilitated. With respect to other subject matter (primarily services) UCC Articles 2 and 2A have worked in mixed transactions with the common law applicable to the services.