• 과학교육연구지
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• 제41권2호
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• pp.195-212
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• 2017

소집단 학습은 소집단 내 학생들 간의 상호작용을 통해 공동의 목표 및 과제를 해결해 나가는 학습 방법이다. 과학 교육에서 소집단 학습은 중요 학습 전략 중의 하나이며, 학업 성취도와 태도 향상에 효과적이다. 소집단 구성은 3명일 때 학생들이 적극적으로 참여하며 과학 탐구 능력 향상에 효과적인 것으로 보고되었다. 그러나 집단의 구성 방법 즉, 동질과 이질 집단으로 구성하느냐에 따라 그 효과가 다른 것으로 보고되고 있다. 따라서 이 연구에서는 집단의 구성에 따라 7학년 학생의 광합성 개념의 생태적 지위에 차이가 있는지를 검증하였다. 이를 위해서 7학년 학생 1107명을 대상으로 이질 집단과 동질 집단은 상위, 중위, 하위로 구분하여 구성하였다. 광합성 개념은 광합성 장소, 광합성 생성물질, 광합성 필요물질, 광합성 환경 요인 영역으로 구분하였다. 광합성 개념의 생태적 지위 변화에 대한 선행 연구에 기초하여 빈도율 4%이상인 개념을 선정하여 설문을 구성하였다. 설문지는 4가지 영역에 각각 제시된 관련 개념들에 대한 관련성 점수와 이해 수준 점수를 측정하였다. 이 연구의 결론은 다음과 같다. 1) 3명의 소집단 수업에서는 과학 개념 학습에 향상이 있었다. 2) 집단 구성 시 평균을 향상시키고자 할 때는 동질 집단으로 구성하고 구성원간의 편차를 줄이고자 할 때는 이질 집단으로 구성하는 것을 제안한다. 이 연구를 통해서 집단 구성에 따른 결과의 이중성에 대한 차이 또는 효과를 검증하는 구체적인 연구가 이루어지길 기대한다.

• The Korean Journal of Ecology
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• 제20권2호
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• pp.83-94
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• 1997

Stomatal closing by ozone and water stress could reduce further ozone injury by inhibition of ozone influx to the tissue. Direct effect of ozone on stomata can be explained from two aspects which are a stimulation of stomatal closing and an inhibition of stomatal opening. An increase of $Ca^{2+}$ influx into cytoplasm by ozone could stimulate potassium efflux ion channel and inhibits inward potassium ion channels. By this mechanism ozone could induce stomatal closing. On the other hand, ozone could inhibit stomatal opening by affecting the activity of $H^{+}$ dependent ATPase of the membrane in guard cells. This would inhibit proton efflux which precede stomatal opening. It is also possible that ozone could reduce the activity of photosynthesis in guard cells which lead to affect the production of osmotically active sugars and energy. Indirect effect of ozone to stomata is through the effect of $CO_2$ elevation as a result of damage of the photozynthetic machinery. This indirect effect is slower than the direct effect.

• 한국해양생명과학회지
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• 제5권1호
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• pp.9-16
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• 2020

Irgarol과 diuron에 각각 노출된 해산규조류(Skeletonema costatum)의 개체군 성장률(r)을 분석하여 독성평가를 실시하였다. S. costatum을 irgarol (0, 0.31, 0.63, 1.25, 2.5, 5 ㎍ l^-1)과 diuron (0,7.81, 15.63, 31.25, 62.5, 125 ㎍ l^-1)에 각각 96시간 노출하여 r을 계산하였고, 대조구의 r은 0.04 이상으로 시험기준에 적합하였다. S. costatum의 r은 irgarol에서 0.63 ㎍ l^-1, diuron은 15.63 ㎍ l^-1 이상에서 대조구 대비 유의하게 감소하기 시작하여 irgarol과 diuron의 농도가 증가할수록 r이 감소하는 농도의존적인 반응을 나타냈고, 시험 최고농도 5와 125 ㎍ l^-1에서 r이 대조구 대비 80% 이상 감소하였다. Irgarol과 diuron에 노출시킨 S. costatum r의 반수영향농도(EC₅₀)는 1.09, 45.45 ㎍ l^-1, 무영향농도(NOEC)는 0.31, 7.81 ㎍ l^-1, 최소영향농도(LOEC)는 0.63, 15.63 ㎍ l^-1으로 나타났으며, EC₅₀ 기준으로 irgarol이 diuron보다 독성이 큰 것으로 나타났다. 본 연구결과로 해양생태계에서 Irgarol과 diuron의 농도가 0.63과 15.63 ㎍ l^-1 이상이 되면, 해산 규조류 S. costatum의 r은 독성영향을 받을 것으로 판단된다. 또한, 독성 값으로 제시된 결과들은 irgarol과 diuron의 기준농도 설정을 위한 기초자료로 유용하게 활용될 것이다.

• 환경생물
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• 제34권4호
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• pp.353-360
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• 2016

중금속 Cd, Cu 및 Zn이 해산로티퍼(Brachionus plicatilis)의 생존율 및 개체군 성장률에 미치는 영향을 알아보기 위하여 중금속 3종에 대한 독성평가를 수행하였다. 중금속에 24시간 노출하였을 때 Cd, Cu 및 Zn에 대한 생존율은 40.00, 0.13 및 $10.00mg\;L^{-1}$ 농도에서 급격한 감소가 시작되어 농도의존적으로 감소하였고, 중금속에 72시간 노출한 개체군 성장률도 Cd, Cu 및 Zn의 12.50, 0.06 및 $1.00mg\;L^{-1}$ 농도에서 급격한 감소가 시작되어, 중금속 3종에서 모두 농도의존적으로 감소하였다. Cd, Cu 및 Zn에 노출된 개체군 성장률의 $EC_{50}$ 값은 각각 21.41, 0.12 및 $6.15mg\;L^{-1}$이며, 독성의 세기는 Cu>Zn>Cd로 생존율과 개체군 성장률이 동일하였다. 또한 Cd, Cu 및 Zn에 대한 개체군 성장률의 LOEC는 각각 6.25, 0.03 및 $0.10mg\;L^{-1}$, NOEC는 각각 12.50, 0.06 및 $1.00mg\;L^{-1}$로 나타났다. 해양환경에서 개체군 성장률의 LOEC를 초과하는 농도가 B. plicatilis에게 독성영향을 미칠 수 있다고 판단되며, NOEC와 $EC_{50}$ 값은 혼합독성을 판단하기 위한 WET test와 해양생태계 내 생물에게 영향을 미치는 중금속 독성에 대한 가이드라인으로 활용될 수 있을 것이다.

• The Korean Journal of Ecology
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• 제20권3호
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• pp.175-179
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• 1997

To explanin allopatric distribution of Carpinus cordata and C. laxiflora in the field the effect of soil flooding on photosynthesis and water relations was tested with field grown saplings. Under the flooding condition stomatal conductance of C. laxiflora decreased markedly from day two after flooding treatment and remanined low throughout the experiment. In contrast, flooding had no effect on stomatal conductance of C. cordata throughout the exper iment. The rate of photosynthesis of C. laxiflora was significantly suppressed under flooding conditions, whereas that of C. cordata was not affected in the flooded condition. On day seven after flooding treatment xylem pressure potential of C. laxiflora significantly decreased. Flooding, however, did not have any effect on the xylem pressure potential of C. cordata throughout the experiment. From these findings it is concluded that there is a difference in resistance to flooding between C. cordata and C. laxiflora and that one of the the factors responsible for allopatric distribution in the two species is flooding.

• KIEAE Journal
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• 제8권2호
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• pp.59-64
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• 2008

This research was performed to activate various new technology for indoor container, and attempt to a desirable planting environment of indoor plant by verify effect that indoor container slit ventilation system gets in growth and root activation of Korea Native Plants. Main result is as following. 1. Davallia mariesii, typical epiphyte fern, was appeared that growth of top and root activation was helped by slit ventilation system in indoor container and were very positive in rhizome development specially. 2. Hedera rhombea was helped growth of top by slit ventilation system, and specially, effect of plant height and number of shoot. Also, this slit system was positive in root activation. So, this indoor container appeared by thing which is very desirable in climbing plants as well as epiphyte plants. According to result that see effect getting in growth and root activation of Davallia mariesii and Hedera rhombea for indoor container slit ventilation system, Growth of top was different in plant but root activation was developed.

• The Korean Journal of Ecology
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• 제21권3호
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• pp.251-255
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• 1998

To elucidate the effects of a hydroelectric dam construction on annual ring growth of Pinus densiflora, the annual ring widths of 68 trees collected from 7 sites were closely examined. The result was analyzed to ask three special questions first, whether there are real effects of dam construction on the radial growth second, would the magnitude of the effect be different due to two periods of under-construction and post-construction the last, would it be different among age classes. Annual ring growth has been significantly enhanced by the dam construction. Specially, its effect was marked after the construction was finished and the reservoir was filled up with water. There was, however, no remarkable evidence that pine growth would be reduced while the dam was under construction, even though there was a minor decreasing trend. The magnitude of the effect was different among age groups. That is, the changed condition after the construction enhanced relatively the growth of aged trees monre. According to other meterological research since the dam was constructed, the reasons of enhancing pine growth assumed to be the increase of daily temperature, the decreased of daily temperature difference and the increased of rainy days.

• Ocean and Polar Research
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• 제35권3호
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• pp.219-228
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• 2013

In Korea, more than 300 oil spill accidents occur every year. Despite the frequency, only a small pool of data is available on the initial effect of oil spill on macrobenthic fauna inhabiting rocky shores. The aim of this study was to analyze the variation of macrobenthic fauna composition and community structure on rocky shores, and understand the impact of oil on rocky shore organisms after the Hebei Spirit oil spill. Field surveys were carried out in five regions dose to the wreck site in January, April and September 2008. Polluted sites after the Hebei Spirit oil spill showed that biological index consistently decreased for 9 months limited to breeding and recruitment of organisms by spilled oil. Macrobenthic community was subdivided into 3 groups by species elimination and differences between density of major dominant species: enriched biota community under a relatively stable environment, the second with relatively low ecological index and the last with poor community. In this study, species number did not clearly reflect the effect of oil on the rare and mobile species. However, mean density, biomass and community structure showed the effect of oil by considering breeding activity, decline in recruitment and variation pattern with time.

• 한국태양에너지학회 논문집
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• 제32권6호
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• pp.134-140
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• 2012

With rapid modernization and industrialization, many urban areas are becoming overcrowded at a rapid pace and such urban ecological problems as heat island effect are becoming serious due to the reduced green zones resulted from the indiscriminate development. To solve this problem, ecological park, constructed wetlands, and greening on the elevation, balcony, and roof of a building that have the structure and function very close to the state of nature are currently being promoted at the urban or regional level. Especially green roof will be able to not only provide the center of a city with a significant portion of green area but also help to relive heat island effect and improve micro climate by preventing concrete of a building from absorbing heat. According to a recent study, the temperature of green roof in the summer season shows a lower temperature than the outdoor temperature, but inversely the concrete surface shows a higher temperature. Accordingly, this study measured the surface temperature of buildings with green roof in Daejeon area in order to determine how the green roof system would have an impact on the distribution of surface temperature and did a comparative analysis of the distribution of the surface temperature of green roof vs non-green roof based on these theoretical considerations. As a result, it was found that the surface temperature of green roof was lower by $4{\sim}7^{\circ}C$ than that of non-green roof. This is expected to contribute to the mitigation of urban heat island effects.

• KIEAE Journal
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• 제7권1호
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• pp.65-72
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• 2007

As ecological design elements, daylighting can be applied to provide adequate illumination on visual tasks to create an attractive visual environment and to save electrical energy. Daylighting control systems reject direct sunlight and penetrate it onto the ceiling or to deep into the room. This study aims to evaluate the luminance environment of sloped light guide with automated venetian blind systems according to sun angle changes. For evaluation, a mock-up model was used and the south facing side-window mounted between the clerestory window and the view window. To assess luminance performance, 3 view points of luminance were monitored. As results, the conventional and lightshelves show ideal luminance ratio between workplane and surroundings(3:1) and workplane and darkness area(2:1) due to total ratio of surroundings and darkness area has lower ratio than workplane. Compared to the lightshelves window, conventional window shows unrelieved effect in between the workplane and brightness area(1:5). It means that there has low deviation according to the required standards. Also, compared to the ratio between the brightness area and darkness area(2~6:1) conventional window with high deviation(10~20:1) provide discomfort glare due to the excessively strong contrast, while lightshelves window shows a required luminance ratio that provide a three-dimensional effect to occupants. Therefore, luminance distribution indicate that application of a lightshelves and blinds not only has a significantly positive effect but also offers higher luminance quality in a daylit room