• KOREAN JOURNAL OF CROP SCIENCE
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• v.15
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• pp.33-59
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• 1974

A series of experiments were conducted at Crop Experiment Station from 1968 to 1971 to obtain basic information on effects of selection on yield of wheat varieties. Heritability estimates, correlation and path coefficients computed for yield and yield related characters from fixed variety groups-Korean, U.S., and Japan; early and late-$F_2$ and $F_3$ generations were studied. The same estimates for fixed variety groups grown under different fertilizer levels and years were also studied. The results were summarized as follow: 1. Three variety groups classified by their origins as Korea, United States and Japan showed high heritability estimates for heading date, plant height and spike length. The heritability estimates for grain number per spike and 1, 000 grain weight were moderate and those for the number of spikes per plant and grain yield were low. Very low estimates of heritability were obtained for grain number per spike and yield of variety group from the Unites States. 2. High genotypic correlation coefficients between 1, 000 grain weight and yield were obtained for all variety groups originated from Korea, United States and Japan and early variety group, except late variety group. The genotypic correlation coefficients between grain number per spike and yield were also high for all variety groups except variety group originated from the United States. 3. The direct effects of 1, 000 grain weight in terms of path-coefficients to yield were high for all variety groups except late variety group. 4. High genotypic correlation coefficients were obtained between 1, 000 grain weight and yield in $F_2$ from. two crosses. The same degree of genotypic correlation coefficients were obtained between grain number per spike and yield, although slight differences in its magnitude were found depending upon the cross combination. 5. The analysis of path-coefficients in $F_2$ shows that the direct effects of yield components to yield were negligible. 6. The characters that showed high genotypic correlation coefficients with yield in $F_3$ were 1, 000 gnain weight and grain number per spike. These characters showed also high direct effects to yield. 7. No great variations of heritability estimates for heading date, plant height and spike length were obtained for either fertilizer responsive or non responsive variety group due to fertilizer levels applied. 8. Heritability estimates of 1, 000 grain weight in fertilizer responsive group and yield in fertilizer nonresponsive group were high as level of fertilizer increased. 9. Heritability estimates for grain number per spike and 1, 000 grain weight of fertilizer non-responsive-group were higher than those of fertilizer. responsive group. 10. Genotypic corretation coefficients between yield and 1, 000 grain weight in fertilizer responsive group were getting lower as the level of fertilizer increased and those in fertilizer non-responsive group were vice versa. 11. Genotypic correlation coefficient between yield and spike number per plant in fertilizer responsive group was high. However, the genotypic correlation coefficient between yield and spike number per plant in fertilizer non-responsive group was low. 12. The direct effects of 1, 000 grain weight to yield were higher than other yield components either in fertilizer responsive or non-responsive group regardless of levels of fertilizer applied. The spike number per plant, however, was high only when high level of fertilizers were applied to fitilizer responsive group. 13. Slight variations of heritability estimates for heading dates, plant height, spike length, grain number per spike and 1, 000 grain weight were obtained between years. However, the spike number per plant with low heritabilility showed great variation between years. 14. The character that showed high genotypic correlation coefficients with yield in two years was 1, 000 grain weight, and this character was also high in direct effect to yield in terms of path-coefficients. 15. From the above experimental results, it might be concluded that 1, 000 grain weight would be one of the most important characters to increase the effects of selection for yield in wheat breeding in Korea.

• Journal of Photoscience
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• v.8 no.2
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• pp.79-82
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• 2001

2-(p-Diethylaminostyryl)pyrrole (I) and 2-[5-diethylaminothienyl]vinyl]pyrrole (II) derivatives with systematic variation of the acceptors have been synthesized and their first hyperpolarizabilities were measured. The $\beta$ values increased systematically as the aromatic resonance energy decreased. Moreover, the value of $\beta$ for the former increased gradually as the acceptor strength increased. The opposite trend observed in the latter series of compounds has been attributed to the distorted structure caused by the steric hindrance between the N-methyl group and the acceptor moiety.

• Korea-Australia Rheology Journal
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• v.19 no.3
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• pp.117-123
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• 2007

There has been considerable interest in recent years in field-responsive suspensions, which are of some importance in industry in many different applications. The microstructure of these materials is a significant issue which can be probed by rheological measurements. In this study, measurements were made of a magnetorheological fluid (MRF) under steady and oscillatory shear flow, with and without a magnetic field. Mathematical inversion was used to derive the relaxation time spectrum of the MRF from oscillatory shear data. Experimental evidence is presented of the gel-like properties of this MRF.

• Journal of the Korean Chemical Society
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• v.65 no.4
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• pp.268-278
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• 2021

The purpose of this study is to subdivide responsive teaching types proposed in the previous study in order to observe the change in the responsive teaching types in teacher educational programs, and to identify factors that impede changes in responsive teaching types. To this end, an educational program including introduction of responsive teaching, case analysis of responsive teaching, individual assignments and group discussions on facilitator type educational scenarios is provided for chemistry teachers who participated in a chemistry education course established in a graduate school of education. Based on previous research, when the teacher's teaching method was analyzed as evaluator, transfer, guide and facilitatore, a type that could not be classified was observed. In this study, responsive teaching types were added by adding two types: explorer and interpreter. In addition, through individual assignments and group discussion data, we could observe the factors that hinder teachers' responsive teaching changes. The obstacles that impede the change to responsive teaching were classified into teacher factors, student factors, and environmental factors. Among the obstacles, teacher factors include a belief in teacher-led instruction, a belief in the role of a teacher as a transfer of knowledge, a belief that the curriculum should be followed, a lack of understanding of the teacher about students, and a lack of the teacher's ability to lead student-led expansion. The student factor was distrust of the student's competence. Also, as an environmental factor, there was an educational environment such as multi-students class. Effective teacher education on responsive teaching can be achieved only when the perception related to these obstacles can be removed.

• Journal of The Korean Association For Science Education
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• v.37 no.1
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• pp.63-75
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• 2017

The purpose of this study is to explore the effect of responsive teaching on students' productive argumentation practice. The participating students predicted the results of an activity to measure in which location on the body (the head, spine, or back of the hand) they would feel a cellphone's vibrations faster. They then engaged in the activity and built an argument to justify it. We interviewed the teacher to understand her thoughts regarding what was expected in the class. We also recorded and transcribed the class and the interview, for use in the analysis of the students' epistemological framing and the teacher's responsive practice in small group argumentation. We discovered that the teacher intervened in the groups with questions that elicited students' thoughts as starting points for her responsive practice. Her eliciting questions led the students to talk about their ideas, supporting their engagement in the argumentation. The teacher's understanding of the argumentation lesson and her behavior to understand the students' ideas reflected her productive framing, which led her to elicit students' ideas and to support their active interaction during the small-group argumentation. She presented rebuttals against students' ideas, engaging in the argumentation as another participant, not as an evaluator. This supported the equality of intellectual authority in the group and showed students how to engage in the argumentation, supporting students' productive framing. As a result of these responsive teaching practices, the students shifted their epistemological framing, resulting in productive argumentation practice. The results of this study will contribute to developing teachers' responsive teaching strategies to support students' productive framing in science classrooms.

• Journal of Families and Better Life
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• v.28 no.1
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• pp.37-49
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• 2010

This study investigated the effects of three factors - children's age, sex and parental feeding styles - on children's self-help skills. The subjects were 213 children and their parents who lived in Kwanak-ku, Seoul. The three-way analysis of variance was employed. The main results were as follows: 1. Children's autonomy was varied significantly according to their sex. Girls do better by themselves than boys do in toileting, washing and drying hands, putting on and buttoning up a coat, putting on clothes, washing and drying their faces. Children's autonomy also varied significantly according to age. A majority of the autonomy subsets increased as the children's ages increased. However, drying their hands with a towel, removing their coats, and drinking water did not vary by age. 2. Children's autonomy also varied significantly according to their parents' feeding style. A responsive feeding style encouraged children to drink water by themselves. 3. The group with the highest score in self-help skills in toileting was 6-year-old girls, and the group with the lowest score was 3-year-old boys. Additionally, the groups with the highest scores in toileting were 4-year-old girls whose parents demonstrated a neglective feeding style, 5-year-old girls whose parents demonstrated an authoritative feeding style, 5-year-old girls whose parents demonstrated a responsive feeding style, 3-year-old boys whose parents demonstrated a responsive feeding style and 6-year-old boys whose parents demonstrated a neglective feeding style. Conversely, the groups with the lowest scores in toileting were 3-year-old girls whose parents demonstrated an authoritarian feeding style, 5-year-old girls whose parents demonstrated a neglective feeding style, and 3-year-old and 6-year-old boys whose parents demonstrated an authoritarian feeding style. 4. The group with the highest score in removing their coats was girls whose parnets demonstrated authoritative, responsive or neglective feeding styles. The group with the lowest score in removing their coats was boys whose parents demonstrated authoritative or neglective feeding styles.

• Journal of The Korean Association For Science Education
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• v.38 no.1
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• pp.69-85
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• 2018

The purpose of this study is to explore teachers' responsive moves that affect students' argumentation practices, and to propose responsive teaching strategies in argumentation-based science classroom. Two teachers, who have not implemented argumentation in their classes, and 57 students, participated in this study. We recorded and transcribed their classes and interviews for the analysis. According to grounded theory approach, we categorized the teachers' responsive moves as focused on either structural or dialogical aspects of argumentation, and qualitatively analyzed their responsive teaching practices in classes. We discovered that the teachers mostly responded to structural rather than dialogical aspects of argumentation, particularly during the students' small-group discussions. This was mainly due to their instructional goals, which focused on the structural aspect of argumentation, and the limited time available for supporting small-groups. Regarding the structural aspects, those responsive moves that explored the students' thinking or facilitated their reasoning helped them to share their thinking and justify their arguments further with recognition of learning goals in the argumentation activities. Regarding the dialogical aspects, which were seen mostly in whole-class discussions, the moves that underlined similarities and differences between arguments, facilitated the sharing of a small-group's arguments with the entire class, or asked a specific student to evaluate the arguments were notable. These moves supported clarification of various small-groups' arguments, which led to reconstruction of coherent argument through evaluation and rebuttal of these arguments, consequentially facilitating dialogical interactions. Based on these results, we proposed responsive teaching strategies in an argumentation-based science classroom.

• Journal of The Korean Association For Science Education
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• v.39 no.6
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• pp.739-753
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• 2019

The purpose of this study is to explore characteristics and limitations of a novice teachers's responsive teaching practice, who framed argumentation productively. One novice teacher and two eighth-grade classes participated in this study. Two of the small student groups with active teacher intervention were selected as focus groups. Students engaged in argumentation activity where they built an argument for hearing if the eardrum was torn. We recorded the class and interviews with the teacher and the students, which were transcribed for use in the analysis of the teacher's responsive teaching practices and epistemological, positional framing. We discovered that teacher thought that he should position himself as a facilitator to encourage students to present ideas clearly and to reach consensus. His framing was consistent in responsive teaching practices. Positioning himself as a facilitator, after he framed the discussion as idea sharing discussion by eliciting and probing students' idea, he framed the discussion as argumentative discussion by taking up students' idea and pointing out disagreement between them. As a result, members of small group 1 engaged in argumentative discussion and reached consensus. However, the teacher's productive framing did not guarantee students' productive argumentation practice. In small group 2, he did not elicit and probe students' ideas successfully. As a result, members of small group 2 did not engaged in argumentative discussions. He responded limitedly to the lack of students' conceptions because of lack of understanding about learners. Also, he mainly attended to students' reasoning, and not to students' framing about argumentation because he considered argumentation only as a tool for conceptual learning. The result of this study will contribute to the establishment of responsive teaching in science classrooms.

• Journal of Korea Multimedia Society
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• v.24 no.2
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• pp.285-294
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• 2021

This study developed a responsive healthcare system that users can easily use in real life to prevent turtle neck syndrome by posture correction. We propose a system that naturally induces direct posture improvement by adjusting the height with a responsive cradle through a turtle neck discrimination algorithm detecting the turtle neck posture in real time using a webcam. The turtle neck algorithm was developed based on machine learning, using the points that the distance relationship between the jaw line and the shoulder varies depending on the posture. For the younger age group, which is particularly problematic due to the increase in the use of IT devices, image data in different situations according to the height and posture of the cradle was collected and learned as a support vector machine classifier. In addition, a height-adjustable cradle that can support a laptop has been created and expanded into a responsive cradle that can be controlled with software by interlocking with the Arduino. Therefore, this service enables posture correction of many modern people suffering from turtle neck syndrome and will become an essential platform in the increasing online environment in the non-contact era.

• Journal of The Korean Association For Science Education
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• v.38 no.1
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• pp.11-26
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• 2018

The purpose of this study is to investigate teachers' responsive practices in whole class discussion after small group argumentation and the underlying epistemological framing. Three teachers and 84 students participated in this study by engaging in argumentation activities about the sensory system. We recorded both their discussions in the classes and our interviews with the teachers, which were transcribed for analysis. The results of the analysis showed that the teachers' responsive practices and the epistemological framing were categorized into four types. By framing the discussion as 'reaching the correct answer through discussion,' the teacher focused on whether students' ideas corresponded to scientific concepts and transferred scientific ideas to the students. By framing the discussion as 'eliciting appropriate conceptual resources and developing them into a scientific idea through critical evaluation,' the teacher engaged in the students' discussion as another participant, and considered the small groups' arguments as resources that could develop into scientific concepts. By framing the discussion as 'sharing small groups' arguments,' the teacher responded by asking for clarification of each group's argument, considering it as a valid argument in its own way. By framing the discussion as 'reaching a consented argument through critical evaluation,' the teacher negotiated students' critical evaluation and revision of the arguments. We explored the implications and limitations of each type of responsive practice and considered that the results of this study will contribute to developing teachers' responsive teaching strategies in argumentation activities.