• The Korean Journal of Rheology
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• v.10 no.2
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• pp.82-91
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• 1998

액정고분자/폴리카보네이트 혼합계로 구성된 분자복합계를 쉬트상으로 가공할 때 취 약해지기 쉬운 횡단면 방향의 물성을 향상시키기 위하여 미세섬유상의 배향을 in-situ 상태 로 적절히 제어할수 있는 Simultaneous Convergent-Divergent(SCD) 다이를 설계·제작하 고 압출실험을 수행하여 얻은 압출 쉬트를 대상으로 구조-물성-가공의 상관관계를 조사하 였다. 액정고분자의 첨가 함량에 따른 토오크와 토출량의 변화는 액정고분자를 10wt% 소량 첨가하였음에도 현저한 감소 효과를 보였으며 약 30wt%일 때 최소로되었다. 이는 액정고분 자가 보강 기능외에 가공특성의 개선에도 큰 효과가 있어 가공조제로서의 가능성을 보이는 결과로 혼합계의 유변학적 특성 결과에서도 확인할수 있었다. 또 DSC와 DMA를 이용한 열 분석 결과 액정고분자의 함량이 증가함에 따라 PC의 유리전이온도가 다소 감소하는 현상을 보임에 미루어 이 혼합계는 부분적으로 상용성을 갖는 것으로 볼수 있으며 모폴로지 분석을 통해서도 이를 확인할수 있었다. TLCP/PC 혼합계로 구성되는 분자복합재를 SCD 다이를 사용하여 제조한 압출 쉬트의 방향성에 따른 기계적 물성은 기존의 쉬트 다이보다 흐름방향 으로는 다소 낮은 물성치를 보이지만 횡단면 방향으로는 물성이 현저히 향상됨을 관찰할수 있었다. 모폴로지 분석결과 기존의 쉬트 다이의 경우 벽면 부근에서는 액정고분자가 미세섬 유상으로 형성되어 흐름방향으로 배향되어 있지만 중심부에서는 액정 상태로 존재하는 반 면, SCD 다이의 경우 미세섬유상으로 형성된 액정고분자가 벽면에서부터 중심부로 갈수록 횡단면 방향으로 서서히 배향되어 있음을 확인할수 있었다.

• Journal of The Korean Association For Science Education
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• v.18 no.2
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• pp.149-160
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• 1998

The purpose of this study was to analyze the 6th national secondary science curriculum and classroom practices to collect the basic data for developing secondary science program focusing on creative problem-solving ability. The creative problem-solving ability was conceptualized as an active process of producing new solutions to problems and consisted of five components: general knowledge, domain-specific knowledge, motivation, divergent thinking and critical thinking. The research questions were generated as follows: (1) Whether creative problem-solving elements-domain specific knowledge(declarative knowledge and inquiry methods) were included or not in the 6th secondary science curriculum, textbooks and teacher's guide? If so, how are they represented? (2) Whether the teachers tried to enhance divergent and critical thinking of their students. Through content analyses, observations and interviews, these research questions were answered as follows: (1) Inquiry methods, which are important to develop creative problem-solving abilities in science, were underestimated in comparison with declarative knowledge. In other words. inquiry methods were regarded only as tools to understand the scientific concepts and principles. (2) It was hard to find the situations which teachers provided opportunities for divergent and critical thinking to their students. Based on these results, the followings were recommended: (1) Inquiry methods should be regarded as a goal not as a tool and be used to acquire inquiry methods themselves. (2) Teachers should not stick to the prescribed inquiry methods prescribed in the textbook, but to give opportunities for thinking various kinds of inquiry methods to improve divergent and critical thinking.

• Journal of The Korean Association For Science Education
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• v.28 no.5
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• pp.482-494
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• 2008

The purpose of this study was to introduce a practical model to enhance creative and critical thinking skills through hypotheses generating activities for students. The 2007 Science National Curricula stresses the need for the enhancement of creative thinking skills for our students. The definition for the creativity in the narrow sense is the divergent thinking skills. The definition of the critical thinking skills is the strong sense of those skills. This model shows the use of the divergent thinking skills and convergent thinking skills together. The divergent thinking skills has been developed by making three alternative explanations about the causal question within a group of students by active discussion. The following procedure includes the selection of the most provable of the three explanations within a group of students also by active discussions. This process needs convergent thinking skills as well as critical thinking skills. This model can be used easily by exchanging from the one explanation about the causal question in any inquiry teaching strategy to three explanations about one. Although the partial modified strategy shows a small difference from any inquiry teaching strategy, but the effect of the enhancement of the creative thinking skills for our students shows significantly better (p<.05). More detailed study will be carried out in the near future.

• Journal of Elementary Mathematics Education in Korea
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• v.16 no.2
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• pp.253-267
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• 2012

In this paper, we primarily focus on the perspectives about creative process, which is how mathematical creativity emerged, as one aspect of mathematical creativity and then present a desirable task characteristic to measure and program characteristics to develop mathematical creativity. At first, we describe domain-generality perspective and domain-specificity perspective on creativity. The former regard divergent thinking skill as a key cognitive process embedded in creativity of various discipline domain involving language, science, mathematics, art and so on. In contrast the researchers supporting later perspective insist that the mechanism of creativity is different in each discipline. We understand that the issue on this two perspective effect on task and program to foster and measure creativity in mathematics education beyond theoretical discussion. And then, based on previous theoretical review, we draw a desirable characteristic on instruction program and task to facilitate and test mathematical creativity, and present an applicable task and instruction cases based on Geneplor model at the mathematics class in elementary school. In conclusion, divergent thinking is necessary but sufficient to develop mathematical creativity and need to consider various mathematical reasoning such as generalization, ion and mathematical knowledge.

• Korean Journal of Child Studies
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• v.28 no.1
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• pp.171-187
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• 2007

The 166 elementary school students of this study were divided into four groups by gender and degree of structure in problem situations. Written instruments ascertained intelligence, conceptual knowledge, science process skills, divergent thinking, intrinsic/extrinsic motivation, personality traits, and home environment. Results were that male students scored higher on problem finding in the ill-structured than in the moderately structured problem situation. In the ill-structured problem situation, personality traits, conceptual knowledge, and intrinsic motivation contributed to the scores of male students and home environment and conceptual knowledge contributed to the scores of female students. In the moderately structured problem situation, personality traits and intrinsic motivation contributed to the scores of all students, but science process skills contributed to the scores of female students only.

• Journal of Korean Elementary Science Education
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• v.25 no.4
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• pp.419-429
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• 2006

This study investigated gender differences in the factors affecting elementary school students' ability to identify scientific problems. Scientific problem finding tasks, involving written instruments including IQ tests, content knowledge, science process skills, divergent thinking skills, intrinsic/extrinsic motivation, personality traits, and home environment were administered to 96 elementary school students(male; 50 & female: 46). The data collected was analyzed by means of a t-test, Pearson's correlation, multiple regression analysis, and canonical correlation analysis. The finding indicated that there were significant gender differences in scientific problem finding performance. Female students were significantly higher in both total score and elaborate score of scientific problem finding than male students. Personality traits and intrinsic motivation positively and extrinsic motivation negatively predicted male students' abilities in scientific problem finding. Science process skills, personality traits and intrinsic motivation positively and extrinsic motivation negatively predicted female students' scientific problem finding and IQ positively predicted female students' elaborate score of scientific problem finding.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.12
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• pp.28-33
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• 2020

Oil-related products have provided many benefits to humanity, but are significant contributors to environmental pollution. As per the International Maritime Organization (IMO) requirements, in the future, all ships must be equipped with filtering equipment and 5ppm bilge alarms that can help remove or reduce oil products during wastewater treatment. In this study, a UV fluorescence measurement system that can detect the oil components in wastewater containing both water and oil was developed. When an excitation wavelength of 254nm was used to irradiate the wastewater, the amount of UV at a divergent wavelength of 360nm was measured to measure the contamination. Based on the measurement, it was concluded that this system is suitable for use as the 5ppm bilge alarm proposed by IMO.

• Archives of design research
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• v.15 no.4
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• pp.307-316
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• 2002

Metaphor thinking is a kind of intuitive thinking and plays a central role in design process. But there are not many researches on this topic because it happens in designer's mind during design problem solving. In this paper, we considered cognitive aspects of metaphorical thinking as they cropped up in the process of design concepts development. As a method of cognitive experiment we used a protocol analysis of the design review reports. At the end of this research we concluded that metaphorical thinking is engaged in restructuring of new frames and reconciliation of conflicting frames for the development of new design ideas and concepts. This role of metaphorical thinking makes the design thinking divergent and the design process creative.

• ALGAE
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• v.26 no.1
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• pp.21-32
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• 2011

Studies of the red algal genus Bostrychia over the last 15 years have made it a model system for many evolutionary processes within red algal species. The combination of newly developed, or first employed methods, in red algal species studies has made Bostrychia a pioneer genus in intraspecific studies. Bostrychia was the first genus in which a mitochondrial marker was used for intraspecific red algal phylogeny, and the first for which a 3-genome phylogeny was undertaken. The genus was the first red alga used to genetically show maternal plastid and mitochondria inheritance, and also to show correlation between cryptic species (genetically divergent intraspecific lineages) and reproductive incompatibility. The chemotaxonomic use, and physiological function of osmolytes, has also been extensively studied in Bostrychia. Our continuous studies of Bostrychia also highlight important aspects in algal species studies. Our worldwide sampling, and resampling in certain areas, show that intensive sampling is needed to accurately assess the genetic diversity and therefore phylogeographic history of algal species, with increased sampling altering evolutionary hypotheses. Our studies have also shown that long-term morphological character stability (stasis) and character convergence can only be correctly assessed with wide geographic sampling of morphological species. While reproductive incompatibility of divergent lineages supports the biological species nature of these lineages, reproductive incompatibility is also seen between isolates with little genetic divergence. It seems that reproductive incompatibility may evolve quickly in red algae and the unique early stages of fertilization (e.g., gametes covered by walls, active movement of spermatium nuclei to the distant egg nucleus), also well investigated in Bostrychia,. may be key to our understanding of this process.

• Journal of the Korean Chemical Society
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• v.55 no.6
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• pp.1056-1073
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• 2011

The purpose of this study was to develop teaching materials using Pyramid model of divergent thinking, Inverse pyramid model of convergent thinking and Diamond model of divergent-convergent thinking. And the teaching materials was implemented to 120 students in middle school over 10 weeks. Results indicated that the experimental group presented statistically meaningful improvement in creative thinking skills, especially in fluency and flexibility(p<.05). Also the teaching materials contributed to improve critical thinking skills, especially in inquiry process of recognizing problems, making conclusion and generalization(p<.05). Moreover, academic achievement was improved(p<.05). But, there was no significant improvement in creative personality(p<.05).