• International Journal of Advanced Culture Technology
• /
• 제11권3호
• /
• pp.106-112
• /
• 2023

This study proposes learner participatory activities for learner-centered college liberal arts classes. In addition, it analyzes learners' perceptions of and satisfaction with learner-centered classes and identifies the issues that must be considered when planning learner-centered activities for college liberal arts classes. The study used a learner-centered participatory activity in which participants created a 4-cut cartoon addressing a specific theme. An open-ended questionnaire was administered to identify learners' attitudes about and satisfaction with the learner-centered classes. It showed that most learners (87.5%) were highly satisfied with the 4-cut cartoon creation activities in the learner-centered participatory class. Learners identified the burden- free nature of the class activities, the fact that they improved their understanding of class content, and that they were fun (not boring) as the main reasons they found the class activities satisfying. In liberal arts English classes, more diverse participatory class activities should be developed to arouse interest and motivation of learners and encourage learners' participation.

• 한국산림과학회지
• /
• 제102권1호
• /
• pp.30-37
• /
• 2013

이 연구는 식생기반재 돌망태의 침식억지효과 및 녹화효과를 분석하는데 있다. 이 연구를 통하여 얻은 결론은 다음과 같다. 조사기간 중 평균침식량을 분석해 본 결과, 침식량이 가장 많은 순으로 보면 곡선부에서의 일반돌망태시공지(5,840 $cm^3$)>대조구(5,833 $cm^3$)>직선부의 일반돌망태 시공지(5,621 $cm^3$)>곡선부의 식생기반재돌망태시공지(4,298 $cm^3$)> 직선부의 식생기반재돌망태시공지(4,117 $cm^3$)의 순으로 나타나 식생기반재 돌망태를 시공한 것이 임도절토비탈면의 침식을 저감하는데 효과적인 것으로 분석되었다. 아울러 임도 곡선부의 식생기반재돌망태 및 일반돌망태시공지의 토양침식억지효과가 직선부보다 낮게 나타나 이러한 구조물은 곡선부보다는 직선부에 설치하는 것이 효과적일 것으로 사료된다. 조사기간 중 평균식생피복률은 곡선부에서 45(28~65)%로 나타나 동일한 기간 직선부 식생기반재돌망태시공지의 평균피복률 56(30~85)% 보다 약 11(2~20)% 낮은 값을 나타내어 직선부에서의 식생피복률이 높게 나타났다. 또한 임도절토비탈면에 시공한 식생기반재돌망태는 안정화된 이후 임도 절토 비탈면의 토양침식을 억지하는 효과로 인해 식생피복률이 증가하는데 기여하는 것으로 분석되었다.

• 현장농수산연구지
• /
• 제24권4호
• /
• pp.30-34
• /
• 2022

본 연구는 일조방해에 의한 광환경의 변화가 절화 장미의 생산성과 품질에 미치는 영향을 분석하기 위해 절화용 스탠다드 장미 'Monet' 품종에 인위적으로 차광 처리하여 일조를 방해하고 일조방해 시간에 따른 장미의 절화수량과 생육특성을 조사하였다. 일조방해 시간에 따른 절화 장미 'Monet'의 단위면적(3.3m²)당 절화수량은 무처리구에서 40본인 반면 4시간, 8시간, 12시간 처리구에서는 각각 32본, 29본, 25본으로 일조방해 시간이 증가함에 따라 절화수량이 감소되는 경향을 나타내었다. 절화 장미의 품질과 관련된 절화 특성의 경우에도 무처리구에 비해 12시간 처리구에서 화폭과 화고, 꽃잎의 길이와 폭 등 모든 특성에서 10~20% 정도 감소하였다. 또한 절화 장미의 상품성을 결정하는 화경장과 꽃대 굵기, 절화중 등의 생육특성도 일조방해 시간이 증가됨에 따라 감소하는 경향을 보였다. 이에 반해 개화소요일수는 24.3일에서 27.7일로 14.0% 증가하는 등 일조방해 시간이 증가됨에 따라 전반적인 생육은 위축되고 개화는 지연되는 특성을 나타내었다. 본 연구의 결과에서 일조방해 시간이 증가함에 따라 꽃의 크기가 감소하고 화경장 및 절화의 생체중 등이 감소한 것은 일조방해로 인해 일평균 광합성광량자속밀도(PPFD)가 감소하고 이에 따라 총광합성량이 감소하면서 장미의 생장과 발달에 필요한 양분을 충분히 공급받지 못했기 때문으로 판단된다.

• 한국기계가공학회지
• /
• 제11권4호
• /
• pp.111-117
• /
• 2012

Dust collecting performance of axial-vane type cyclone for oil mist was analyzed in this study. For predicting cut diameter size of cyclone, the number and angle of vane ($tan{{\beta}_2}^{\prime}$) was simulated by CFD. As the result, $tan{{\beta}_2}^{\prime}$ was decreased as the number of vane was increased and the angle of inclination(${{\beta}_2}^{\prime}$) decreased, and it cause strong swirl flow. Therefore, it could be confirmed that as the number of vane was increased and the angle of inclination was decreased, cut diameter size was decreased. Also, by verifying the results of CFD through experiment, the cut diameter size could be $2{\mu}m$ at $4m^3/min$ of flow rate.

• Corrosion Science and Technology
• /
• 제9권1호
• /
• pp.29-33
• /
• 2010

Laser machining technique, which is used focusing pulse YAG laser beam irradiation was applied to form area ratio controlled model cut-edge on pre painted Zn coated steels. A corrosion behavior of formed model cut-edge was investigated by rest potential measurement in 1 mol $m^{-3}$ NaCl with and without 0.5 kmol $m^{-3}$ $H_3BO_4$/0.05kmol$m^{-3}$ $Na_2B_4O_7$. The rest potential showed almost constant value with fluctuations. The amplitude of fluctuations increased with exposed area of steel surface. White corrosion products of zinc oxide and simonkollite was formed after the experiments at the formed model cut-edge.

• 한국철도학회:학술대회논문집
• /
• 한국철도학회 1999년도 추계학술대회 논문집
• /
• pp.234-241
• /
• 1999

Rails have residual stresses produced during manufacturing processes. The residual stresses play all important role on brittle fracture, fatigue strength and derailment by producing cracks in the web of rail. The web saw-cut test is a technique developed to measure the bulk longitudinal residual stress level. It is a simple mettled to estimate a stress intensity factor, $_{4}$ for a web crack by using the radii of curvature of the upper and lower portions of a cut rail. But according to this method, $_{4}$ varies along the rail length because the curvatures along tile rail length vary In this paper, tile residual stress was estimated by Finite Element Method and tile web saw-cut method. In addition tile variation of the residual stress with time was investigated.

• 터널과지하공간
• /
• 제4권3호
• /
• pp.237-249
• /
• 1994

A new type of cut method, called SK-cut, was developed in order to overcome the shortcomings of the conventional V-cut and Burn-cut blasting methods. Total 190 times of test blasts were performed for the evaluation of the efficiency of new blasting method. V-cut, Burn cut and SK-cut were compared by applying them to the excavation of main gallery and construction tunnel of underground oil storage cavern. Test results showed that excavation efficiency of the new method was increased by 5.9~9.8% and that specific charge was reduced to 71~92%.

• 한국초지조사료학회지
• /
• 제11권3호
• /
• pp.189-194
• /
• 1991

This experiment was carried out to investigate the effect of pure mineral nitrogen fertilization on dry matter yield and to determine the amounts of advisable mineral nitrogen according to difference of annual precipitations in permanent grassland. The results obtained were as follows: 1. Only PK-fertilizing without additional mineral nitrogen application produced 6. 9 tonlha of annual dry matter yields on average in relatively wet years that was higher than in rel. dry and normal years under 3-cut system by 0. 7 and 0.6 ton DMIha, respectively. 2. Due to the lesser rainfall the nitrogen-efficiency was substantially higher with heavy dressing of nitrogen fertilizer. The absolute differences in yield between rel. dry and wet years were 0.4 and 0.7 ton DMIhalyear respectively when dressed with 90 and 120 kgN/ha/cut at 4-, 5- and 6-cut systems, whereas at 3-cut system differences around 1.3 and 1.1 ton Dhllhalyear respectively were recorded. 3. In rel. dry years the most efficient N-dressing rates per ha and year tended to be slightly higher than in rel. wet and normal years. Particularly at 5-cut system 4-7 kg/ha/cut of more nitrogen fertilization was required in order to obtain the highest overyields. 4. The N-dressing rates needed to maintain a nitrogen-efficiency of 8 to 16 kg DM/kg N tended to be stronger particularly at high cut system, and also in rel. dry years higher dressing rates were required that in rel. wet and normal years.

• 한국자기학회:학술대회 개요집
• /
• 한국자기학회 1999년도 추계연구발표회 논문개요집
• /
• pp.40-41
• /
• 1999

• 국제초고층학회논문집
• /
• 제8권4호
• /
• pp.303-311
• /
• 2019

The effectiveness of aerodynamic modification to reduce wind loadings has been widely reported. However, most of previous studies have been investigated dynamic forces and pressure distributions on tall buildings with various unconventional configurations. This study was investigated dynamic characteristics and aerodynamic instability of super-tall buildings with unconventional configurations through extensive aeroelastic model experiments. Seventeen types of supertall building models were considered such as basic and corner modification with corner cut, chamfered, oblique opening, tapered, inversely tapered, bulged, helical with twist angles of $90^{\circ}$, $180^{\circ}$, $270^{\circ}$, $360^{\circ}$ and composite with $360^{\circ}$ helical & corner cut, 4-tapered & $360^{\circ}$ helical & corner cut, setback & corner cut, setback & $45^{\circ}$ rotate. As a result, aerodynamic characteristics of helical models with single modification are superior to those of other models with single modification. However, effect of twist angle for helical model is negligible. Further, the 4-tapered & $360^{\circ}$helical & corner cut model is most effective in reducing the along- and across-wind fluctuating displacement responses in all of experimental models.