• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.31 no.1
• /
• pp.30-42
• /
• 1986

In order to find out the best media, explants and environmental conditions for induction of calluses and organogeneses of Pinellia ternata (Thunb.) Breit in vitro, various parts of adult have been cultured on Murashige & Skoog's medium containing various levels of 2,4-dichlorophenoxy acetic acid(2,4-D) and kinetin. The results obtained were as follows: Calluses were induced from the surface of apical meristem and leaf tissue. Formation and growth of calluses in petiole ex plants were best on the MS medium complemented with 2,4-D 2.0 mg/l and kinetin 0.2mg/l. But callus formation in stem ex plants of the nearest tuber was not induced at all kinds of media. Plantlets occured at all treatment except absence of growth regulator. Their numbers, size, leaf and fresh weight were promoted by 2,4-D 2.0mg/l and kinetin 0.2mg/l. Root growth was increased on the medium containing higher 2,4-D concentrations. Size and fresh weight of callus were increased at 25$^{\circ}C$ compared with 10, 20 and 30$^{\circ}C$, respectively. Optimal pH value was at 6.0 for growth of callus. Morphological aberrations were observed in plantlets, especially in regenerated leaves. The separation of the broad leaved plantlets and albino were observed in some cultures. Growth of plantlets after transplantation was best in pots with the sterilized vermiculte. But abnormal variants withered up.

• The Journal of the Petrological Society of Korea
• /
• v.16 no.1 s.47
• /
• pp.12-26
• /
• 2007

We have studied orientational characteristics of vertical rift and grain planes developing in 108 quarries for Mesozoic granites. Orientations of these planes vary in different localities. In general, orientations of these planes are predominantly NNE in South Korea. From the regional distribution chart, orientations of these planes show three dominant sets in terms of frequency orders: (1) $N2{\sim}10^{\circ}E(1st-order),\;(2)\;N15{\sim}25^{\circ}E(2nd-order),\;(3)\;N45{\sim}70^{\circ}E,\;N10{\sim}30^{\circ}W\;and\;N70{\sim}80^{\circ}W(3rd-order)$. These granite quarries are classified by the relative difference in the easiness of rock splitting between horizontal and vertical quarrying planes into: R-type, G-type, and H-type. The results showed that quarries for Triassic granites belong to R and G-types;those for Jurassic granites belong to R, G and H-types. In addition, quarries for Cretaceous granites belong mainly to R-type. Among these quarry types, the most diverse type was identified in the quarries for Jurassic granites. R-type (77.8%) shows a higher distribution ratio compared with G and H-types (22.2%). In general, anisotropy of physical properties is found in granitic rocks and there exists close correlation between orientations of granitic rock splitting planes and those of the open microcracks. Meanwhile, it has been reported that preferred orientations of open microcracks suggest maxinum principal stress orientations.

• Journal of The Korean Association For Science Education
• /
• v.42 no.5
• /
• pp.501-514
• /
• 2022

This study aims to reveal what is necessary for pre-service science teachers to make good use of online formative assessment in the context of online classes. For 22 pre-service physics teachers, first, the preliminary perception of online classes, online formative assessment, and formative assessment was investigated; second, the practice process of online formative assessment was examined. Then the differences between perception and practice were compared and analyzed. Data were collected in preliminary surveys, lesson plans, online formative assessment items, and interview data. As a result of the study, an interaction was mentioned as the difficulty of online classes in the preliminary perception, and pre-service teachers mentioned the use of technology, feedback, and adjustment as advantages of online formative assessment. In most cases of practice, the automated feedback was used using the platform's technology, but it did not lead to adjustment and interaction. In addition, the use of items in online formative assessment was not suitable for formative functions. The reason why the interaction using formative feedback did not occur seems to be because the understanding of formative assessment was insufficient. Pre-service teachers need to be prepared for the 'formative' function through the feedback of online formative assessment so that can lead to interaction in online classes. The shift to online classes is creating difficulties, especially in interaction. It is necessary to prepare and educate pre-service teachers on fundamental aspects that can overcome these difficulties.

• Journal of The Korean Association of Information Education
• /
• v.23 no.5
• /
• pp.481-489
• /
• 2019

In order to explore the learning attitude of the learners and the effects of conscious learning attitudes on academic achievement in On-line education system of open high school, we analyze the log data of 2,965 first graders who studied English, Math, Integrated Society and Integrated Science during the first semester of 2018. This study examines the learning status according to the learner's background variables, and analyzes the number of lessons per hour, learning progress rate, learning period, learning start month, and formative evaluation results for each class. In addition, to verify the effects of conscious learning attitude on academic achievement, skewness and kurtosis are calculated by using learning frequency values for each class. As a result, in almost all fields, the average number of lessons per class, study duration, progress rate, and grades, women are higher than men. In addition, the older ones are, the higher they are and the Seoul area is higher than the other area. The average learning period is 2~3 months, and the longer the learning period, the higher the formative evaluation score. Lastly, even though the number of learning is lower than that of learners who concentrate on a certain period of time, the formation scores of learners who learn consciously are higher.

• The Journal of the Korea Contents Association
• /
• v.16 no.2
• /
• pp.618-632
• /
• 2016

In Korea's drama industry, a production factor has several prices, not one, bucking the general economic theory. The price changes depending upon the broadcaster, the producer, and even the genre. The price gets determined by such factors as the scarcity, the substitutability, the overall budget size, and so on. For star actors, the price stands for their popularity and ego, which makes them strive so desperately for a higher pay than competitors. The rise of the production factor price has outpaced that of the production budget, to cause undesirable structural problems. It is deemed that the running guarantee could be a way to rationalize the pricing system for production factors in Korea.

• 한국HCI학회:학술대회논문집
• /
• 2006.02b
• /
• pp.480-486
• /
• 2006

본 연구는 대학생을 대상으로 사이버 강좌에서 사용되는 세가지 정보제시 유형에 따라 학습자의 학습 수행, 콘텐츠 만족도, 그리고 학습성취 기대감에 어떤 차이가 있는지를 알아보고자 하였다. 이에 공기펌프 작동원리, 브레이크 작동원리, 번개형성과정의 세가지 과제를 나레이션+텍스트(na+text), 나레이션+삽화(na+illust), 나레이션+애니메이션(na+ani)의 세가지 정보제시 유형의 콘텐츠를 제작하였다. 먼저 학습수행에 있어서는 브레이크 과제에서 정보제시 유형별 유의한 차이가 나타났으며 세가지 정보제시 유형 모두에서 na+illust, na+ani, na+text 조건 순으로 성취가 높았다. 번개형성과정에서도 정보제시 유형별 유의한 차이가 있었고, na+text, na+ani, na+illust 의 순으로 학습성취가 높은 것으로 나타났다. 콘텐츠 만족도에 있어서는 공기펌프와 브레이크 과제 모두에서 제시유형별로 유의한 차이가 있는 것으로 나타났으며, na+ani, na+illust, na+text 순으로 만족하는 것으로 나타났다. 학습성취에 대한 기대감도 공기펌프와 브레이크 과제 모두에서 유의한 차이가 있으며, 그 순서는 만족도와 동일하였다. 이 연구의 결과는 나레이션이 제공되는 3 가지 정보제시 유형의 콘텐츠를 학습함에 있어 학습과제와 학습과제 제시 유형에 따른 학습 수행의 차이를 확인할 수 있었다. 또한 이러한 학습수행 결과는 피험자의 콘텐츠 만족도와 학습 성취 기대감과는 다른 패턴을 보임으로써 정보제시 유형에 대한 평가와 실제 학습수행과는 차이가 있음을 시사한다.

• 한국지구과학회:학술대회논문집
• /
• 2010.04a
• /
• pp.25-25
• /
• 2010

본 연구는 에너지와 물질 순환을 주제로 한 대학생들의 집단적 과제 수행 상황에서 구성원들의 상호작용 기능과 요소에 따른 역할 분배의 양상을 밝히고자 하였다. 집단 내 구성원에게 개별적인 역할이 주어져 있지 않은 상태에서 과제가 부여되었을 때, 집단 내에서 자연스럽게 형성되는 역할의 종류를 상호작용 기능과 양상에 따라 유형화해보았다. 연구 참여자는 9명의 환경 교육 전공 대학생으로, 2008년 11월에 열린 한중일 환경교육 캠프에 참여한 한국 학생들이다. 캠프 활동 중 하나로 충남 홍성 문당리 환경농업마을의 에너지와 물질 순환에 대해 토의하고 그 결과를 그림으로 표현하여 발표하는 활동이 있었는데, 본 연구에서는 발표를 위해 준비하는 과정을 연구 맥락으로 하였다. 그리고 약 2시간에 걸친 과제 수행 과정을 촬영 후 전사하여 연구 자료로 삼았다. 관련 선행 연구 고찰과 연구 자료에의 적용 및 수정을 통해 상호작용 기능과 요소를 코딩하기 위한 분석틀을 마련하였으며, 문제가 제기되고 그 문제에 대한 합의가 이루어지는 대화를 분석의 단위로 정하였다. 대화 단위별로 구성원 간 말차례가 오고간 모습을 화살표로 도식화하여 대화 패턴을 분류하였으며, 대화를 말차례별로 상호작용 기능과 요소에 따라 코딩화하였다. 화살표로 도식화된 대화 패턴과 상호작용 코딩 결과에 따라 집단 내에서 자발적으로 형성되는 구성원의 역할을 분류하고 명명하였다. 이렇게 집단적 과제 수행 상황에서 학생들에 의해 자생되는 역할을 상호작용의 관점에서 유형화해봄으로써 협동 학습이나 토의 활동 등 집단적 상호작용을 통한 과제 수행에 있어서 학생이나 교사의 역할에 대해 시사점을 줄 수 있을 것이다.

• Journal of the Korean Institute of Intelligent Systems
• /
• v.17 no.3
• /
• pp.316-321
• /
• 2007

We propose a quatitative annotation method for edges in Bayesian networks using given sets of condition-specific data. Bayesian network model has been used widely in various fields to infer probabilistic dependency relationships between entities in target systems. Besides the need for identifying dependency relationships, the annotation of edges in Bayesian networks is required to analyze the meaning of learned Bayesian networks. We assume the training data is composed of several condition-specific data sets. The contribution of each condition-specific data set to each edge in the learned Bayesian network is measured using the ratio of likelihoods between network structures of including and missing the specific edge. The proposed method can be a good approach to make quantitative annotation for learned Bayesian network structures while previous annotation approaches only give qualitative one.

• Proceedings of the KAIS Fall Conference
• /
• 2007.11a
• /
• pp.133-135
• /
• 2007

PMMA (polymethyl metha crylate) 유기막의 농도별 최적화를 위하여 1, 2, 4, 6, 8 wt.%의 PMMA 농도별로 Al/PMMA/ITO/Glass 구조의 MIM (metal- insulator-metal) 캐패시터 소자를 제작하였다. 유기 절연층의 형성은 ITO/Glass 기판 위에 PMMA를 용질로, Anisle을 용매로 사용하여 스핀코팅법으로 소자를 형성하였다. 제작된 소자에 대해 농도에 따른 전기적 특성을 조사한 결과 누설전류는 2wt.% 농도의 PMMA로 제작된 소자에서 0.3 pA로 가장 우수한 결과를 얻을 수 있었다. 또한 동일한 PMMA 농도로 제작된 캐패시터 소자의 정전용량은 1.2 nF으로 가장 좋은 결과를 얻을 수 있었으며, 계산된 값과 매우 유사한 값을 얻을 수 있었다.

• KOREAN JOURNAL OF CROP SCIENCE
• /
• v.21 no.1
• /
• pp.125-131
• /
• 1976

To study the effects of temperature, day length, and various plant growth regulator treatments on the tuber formation of Irish cobbler, this experiment was carried out with 2 combinations of day-length and temperature and 11 kinds of growth regulator, including GA, and their combinations. For the tuber formation, low temperature-short day condition played decisive role, and exceeded the effects of growth regulators. 4 times foliar application of 10 ppm GA resulted marked elongation of stolon but did not inhibit the tuber formation even under high temperature longday condition.