• Journal of The Korean Association For Science Education
• /
• v.38 no.5
• /
• pp.611-623
• /
• 2018

This study investigated verbal behaviors and interactions in the processes of making written test items using paired think aloud problem solving for pre-service secondary chemistry teachers. The processes of making written test items using paired think-aloud problem solving in four small groups consisting of two pre-service chemistry teachers were recorded and transcribed. The analysis of the results revealed that 'item making' for ten subcategories for solver's verbal behaviors were most frequently exhibited regardless of 'integration' among the components of pedagogical content knowledge (PCK). The solver's 'provide', 'modify', 'require agreement', 'ask', 'agree', and 'justify' were also frequently exhibited although fewer than 'item making'. Especially, the solver's 'ask' was more frequently used in 'non-integration', whereas 'justify' was more frequently used in 'integration'. In listener's verbal behaviors consisted of eight subcategories, 'point out', 'ask', and 'agree' were frequently exhibited regardless of 'integration'. Listener's 'ask' and 'agree' were exhibited more in 'non-integration', whereas 'point out' was exhibited more in 'integration'. Many verbal interactions were analyzed to be in 'symmetrical type' more than 'solver-dominant type' or 'listener-dominant type'. 'Symmetrical type' was also more frequently exhibited in 'integration', whereas 'solver-dominant type' was more frequently exhibited in 'non-integration'. There were little differences between 'integration' and 'non-integration' in 'listener-dominant type'. In 23 subcategories of 'symmetrical type', 'ask-provide' and 'point out-justify' were most frequently found. Especially, 'ask-provide' was more frequently found in 'non-integration', whereas 'point out-justify' was more frequently found in 'integration'. 'Point out-modify' was the most frequent in 4 subcategories of 'listener-dominant type', while 'item making-agree' in three subcategories of 'solver-dominant type' regardless of 'integration'. However, only a little of other subcategories of the three types were found.

• Korean Journal of Plant Resources
• /
• v.29 no.1
• /
• pp.136-142
• /
• 2016

Lespedeza species are mainly used for wildlife food and cover and for erosion control. The germination of these species can be enhanced after a fire occurrence in forest, which is known as fire-activated seeds to germinate. While the heat treatment could break seed dormancy of Lespedeza, its germination rate was quite low. We investigated that chemical scarification could promote germination of L. tomentosa. Seeds were soaked in 100% sulfuric acid (H₂SO₄) for 0, 1, 3, 6, 12, 24, 48, 96, 192, and 384 min, and then washed in distilled water for 24 h. Very few seeds were germinated in control (H₂SO₄ for 0 min). More than 90% of seeds were germinated in H₂SO₄ for 24, 48, and 92 min. However, some damage was observed in roots and cotyledons of seedling dipped in H₂SO₄ for a long time. To search the optimal soaking time in H₂SO₄ without defects, seeds scarified in H₂SO₄ for 30, 60, 90, 120, 150, 180, and 300 min were sown the commercial soil medium. Seeds treated with H₂SO₄ for 90 min and 150 min emerged by about 92% and 84%, respectively. Therefore, H₂SO₄ treatment could break the seed dormancy of Lespedeza species, and especially in case of L. tomentosa the optimal treatment time in sulfuric acid was one to two hours. Germination of L. tomentosa began promptly following the scarification and was completed within about one month, indicating that seeds has no physiological dormancy, just has physical dormancy.

• Journal of Korean Society of Forest Science
• /
• v.43 no.1
• /
• pp.6-13
• /
• 1979

In order to substract the time and cost of propagation for inducing the haploid plants per each species. 500 anthers of late uninucleate microspore on early binucleate microspore stage of Robinia pseudoacacia (Fuel tree) Punius granatum (Ornamental tree). Aleurites fordii (Faty tree) and Styrax japonica (Silvicultural tree) were cultured on the modified Murashige and Skoog's medium supplemented with Kinetin, 2.4-D and NAA as growth regulators. And I observed the samples of cultured anthers under the microscope which were made by Microtoming method and Paraffin method. The results were summarized as follows: 1) Among 500 cultured anthers per each species, anther numbers inducing the diploid callus were as follow: Styrax japonica 20 (4% for the species total); Aleurites fordii 10 (2% for the species, total) and Punica granatum 45 (9% for the species total) were showed. 2) 2n Callus were induced from anther wall. but haploid callus were induced from anther locule. 3) Haploid callus were induced only in 25 anthers (5% for the species total) of Robinia pseudoacacia. 4) These haploid callus were not originated from body cell of anther wall tissue, but from reduced microspores, 5) Since already reported many herbaceous haploid plants were induced from the callus which were originated from reduced microspores, I conclude that the anther of woody plant which induced the haploid callus also will be cultured haploid plant.

• Journal of The Korean Association For Science Education
• /
• v.33 no.5
• /
• pp.893-910
• /
• 2013

The purpose of this study was to identify changes in mental models of students in the elementary school about causes of seasonal changes. During a total of eight sessions, eight sixth graders were asked to describe the causes of seasonal changes through pictures, writing and thinking aloud by using microgenetic research methods, and the changes in mental models were examined. When the research was conducted, linguistic and behavioral factors and contents of interviews of participants were recorded on video. Moreover, a variety of materials such as field observation chart were written by a researcher and mental models records were written by a student. The protocol was written by integration of collected results, and it was repeated to read and was inductively categorized. The results of this study were as follows: First, participants' mental models about causes of seasonal changes were changed in various paths within and across sessions. Participants' mental models that had been more changed in various ways were closer to the scientific model. In addition, like rotation and revolution, students who correctly established the preconceptions related to seasonal changes formed the mental models consistent with scientific concept based on new information. On the other hand, students who did not correctly establish the preconceptions did not deviate from non-scientific mental models. Second, prior knowledge, experience and information which participants held in advance, accuracy of prior knowledge, resolution of inconsistency between new knowledge and existing mental models, activation of mental models through operation of models and drawing an picture affected the changes of mental models. Teachers should provide to learners with sufficient experience which can be configured to various mental models in order to form the scientific concepts. And they need to let learners feel the doubt and resolve it through presentation of new teaching material which is inconsistent with the existing mental models.

• Journal of The Korean Association For Science Education
• /
• v.36 no.5
• /
• pp.739-756
• /
• 2016

The purpose of the study is to reflect on 'myself' as a teacher educator of college of education in depth and to improve my instruction through self-study with three critical collaborators. 17 pre-service science teachers and I have participated in this study of a teacher educator's course since March 2016 after the preliminary practice in 2015. The video recorded the course for 11 weeks with about 40 hours of lessons. The data source also included teacher educator's reflective journals, lecture evaluations, online boards and so on. Questionnaires were distributed and answered both at the beginning and at the end of the course and pre-service teachers wrote their reflective journals. Four of them were in the focus group interviews. During the course, the weekly group meeting of critical collaborators analyzed the emerging issues based on the lesson clips and teacher educator's reflective journals with discussion for the course innovation. Four phases were revealed in the process and for the purpose of the course such as exploration, conflicts, challenges, and changes. The results showed that first, we identified tensions among the teacher educator's multiple identities as a lecturer, a faculty member, and a researcher. Second, there were differences between goals of teacher educator and pre-service teachers in the course, and this obstructed the success of the course sometimes. Third, these practices led to explore balanced alternative views and interpretations of the problem by critical views and to expand and improve our teaching practice and thinking. In addition, the self-study with critical collaborators helped to bring conflicts and issues below my practice to light for collaborative reflection and it gave a chance to understand ourselves as teacher educators in different ways.

• Journal of Korean Society of Forest Science
• /
• v.38 no.1
• /
• pp.46-54
• /
• 1978

In afforestation of denuded forest land soil conditions play a very important role in early growth of cover vegetations. This study was designed for understanding the effect of soil moisture regime on growth and nutrient uptake of some seedlings. Cover vegetations such as Pinus rigida Miller, Robinia pseudoacacia L. and Lespedeza bicolor Turcz. were planted in pot with the soil transported from denuded forest land in Musu-ri Sannae-Myeon. Daedeog-Kun, Chungnam Province. There were 3 moisture treatments and 4 fertility levels in $P_2O_5$ with 4 replications. Influence on growth was observed by the variation in dry weight and nutrient uptake was studied in nitrogen, phosphate and kalium. Results are as follows: 1. For Pinus rigida seedlings decrease in soil moisture tension increases growth of dry weight and enhance the uptake of kalium. Increase in $P_2O_5$ fertility level tends to decrease the uptake of kalium rather than increase in $P_2O_5$ uptake. 2. In Robinia pseudoacacia increase in soil moisture content stimulates the uptake of nitrogen and kalium. Increase in $P_2O_5$ level enhances the uptake of $P_2O_5$ and increases growth of dry weight. 3. In Lespedeza bicolor increase in soil moisture content has a tendency of decrease in nitrogen uptake. Increase in $P_2O_5$ level increases the growth of dry weight as well as the uptake of $P_2O_5$.

• Journal of Korean Home Economics Education Association
• /
• v.16 no.2
• /
• pp.37-53
• /
• 2004

The purpose of this study is to observe the developmental Process of interaction and attitude of children through instruction for “making fabric doll”. Based on the theory of “Waldorf Education”, instruction of 8 hours for 3 weeks exercised against 40 children(18 boys, 22 girls) of 6th grade, especially focused two group(10 children), in K elementary school in Chunchoen. The results of the study by qualitative research method through observing, recording, interpretation are as follows 1. The changes in interaction among children were observed in increase of quantity and quality of conversation among children, of reliability and dependence among children, of intimacy and cooperation among children, and of intimacy between teacher and children. 2. The changes in the attitude toward instruction were observed in increase of confidence and satisfaction, of active and attentive attitude to instruction via more interest about own fabric doll, of positive attitude through attachment to the doll. Therefore, the instruction of “making fabric doll” based on “Waldorf Education” seems to be efficient to child development and Practical Arts Education.

• Korean Journal of Environment and Ecology
• /
• v.31 no.2
• /
• pp.252-265
• /
• 2017

This study aims to analyze the landscape ecological characteristics of green spaces within built up area of high density and evaluate the potential applicability of green patches, thereby introducing urban garden for generating green networks in residence areas. To this end, Yeoksam-Dong was selected as the site area since it is classified as both green initiative zone and alienated area of park service in Seoul. First, the current condition of green spaces in Yeoksam-Dong was identified by five categories: Street trees, private garden, public pocket garden, rooftop garden, and park. Then, the landscape index analysis through FRAGSTATS and connectivity assessment via multi-buffer zone analysis were carried out for analyzing the green networks and evaluating the potential value of green space. The results showed that the degree to which green areas in the site were distributed is arranged in the order of street tree, private garden, public pocket garden, park, and rooftop garden. In case of the street trees whose total core area (TCA, $1,618m^2$) is as high as the park's ($1,128m^2$). Private garden has potential for green network in built up area of high density by gardening since the shape of the patches are irregular (ED = 78.1m/ha) and the average distance among the patches is close (ENN=33.9m). Public pocket garden has also potential for gardening according to the result that it was found to be distributed evenly (LPI=5.7%, SHEI=0.9) with exposing external disturbance ($TCA=66m^2$). For the green network, 84% of all the study site is covered by small green network in 50m butter range of connected green area. The effect of green network was expected through gardening in public pocket garden (27%) and street tree (26%). Accordingly, it is encouraged to actively utilize street tree, private gardens, and rooftop gardens and to establish the urban gardens like local-based community gardens in public pocket garden where a variety of activities can be carried out near residential areas. By doing so, green networks can effectively be established in built up area with high density. The results of this study can contribute positively to fostering the creation of various types of urban gardens.

• Journal of Bio-Environment Control
• /
• v.18 no.2
• /
• pp.166-170
• /
• 2009

The temperature fluctuations was investigated in cold distribution chain of radish sprout, typical of commercial practice. Although the temperature of distribution chain was maintained below 5$^{\circ}C$ in precooling and packaging steps, and 10$^{\circ}C$ in transporting, temperature of loading step increased up to 18$^{\circ}C$ at market. Based on this investigation, the simulated cold distribution conditions were consisted of precooling and packaging step; 5$^{\circ}C$ for 12 hours and transporting and loading steps; 5$^{\circ}C$, 10$^{\circ}C$, 20$^{\circ}C$ and $^{\circ}C$ for 6 hours, and storage and market steps; 5$^{\circ}C$ and 10$^{\circ}C$ for 17 days. The radish sprouts were cultivated at 25$^{\circ}C$ and dark condition for S days and placed in light condition for greening. They were packaged by 25 ${\mu}m$ ceramic film after precooling for 6 hours in 5$^{\circ}C$. The fresh weight loss and visual quality of radish sprout decreased with the increase of the temperature in transporting and loading steps. The carbon dioxide content of packages increased, but the oxygen content decreased rapidly in 1day after storage, as the temperature of transporting and loading steps increased. The ethylene content in packages increased fastest in higher temperature of transporting and loading steps treatment, and showed highest in 5$^{\circ}C$-30$^{\circ}C$-10$^{\circ}C$ treatment (temperature of precooling and packaging steps for 12 hours - temperature of transporting and loading steps for 6 hours - temperature of storage step for 14 days) followed by 5$^{\circ}C$-20$^{\circ}C$-10$^{\circ}C$ treatment. The high temperature of transporting and loading steps resulted in deterioration qualities and atmosphere conditions in packages of sprout. These results suggested that the temperature fluctuation in distribution should influence the shelf-life of radish sprouts, even thought the periods of fluctuation was just 6 hours.

• Journal of The Korean Association For Science Education
• /
• v.30 no.6
• /
• pp.870-885
• /
• 2010

The purposes of this study are to examine what the participants experienced when developing Content Representation (CoRe) of "molecular motion" for the 7th grade in collaboration with experienced chemistry-trained teacher and non-chemistry-trained teacher and to investigate how the participants' PCK changed in their classes after developing CoRe. The participants were one experienced chemistry-trained teacher, two physics-trained teachers, and one researcher. The participants were selected by purposeful sampling. For this study, the discussions on developing CoRe was recorded and two physics-trained participants' classes were video-taped, and constructed/semiconstructed interviews were conducted. All data were transcribed for analysis. The participants experienced reflective thinking of their knowledge and previous classes, corrected their own misconception and clarified those conception, recognized the contents and the goals of "molecular motion" class, enhanced understanding of students' preconception during the development of CoRe. Especially, the two physics-trained teacher-participants confessed that they recognized clearly the contents and the goals of "molecular motion" class and identified their deficiency in 'particle viewpoint' in their previous classes. Their recognition was realized in the course of interaction with experienced chemistry-trained teacher. Among the components of PCK, knowledge of science curriculum was most influent on two physics-trained teacher-participants' classes, and they emphasized 'particle viewpoint' and 'molecular motion' in their classes. In addition, they introduced new teaching strategies that were discussed in the course of developing CoRe. The influence on the participants' PCK was different according to their reflective thinking on their own knowledge and previous classes and their affective characteristic. The implication of this study is that, the course of developing CoRe can promote reflective thinking that is essential for increasing teachers' professionalism and significantly influence on PCK. Especially, developing CoRe in collaboration with experienced chemistry-trained teacher and non-chemistry-trained teacher can identify deficiency in their classes and thereby, improve their classes. And, it takes time and effort to internalize the participant's recognition in their teaching practice.