• Journal of the Korean Chemical Society
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• v.45 no.1
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• pp.83-89
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• 2001

This study was to examine middle school students' understanding of dissolution. More than 75% students understood that dissolution was caused by small particles' filling the space between large particles due to the difference of size among particles. Some other students responded that solute disappeared or was absorbed in a solvent as the result of dissolution. Besides, they didn't know that space between particles was the reason of the volume's decreasing after the process of dissolution. Instead, they explained that space between particles caused dissolution. And they hardly understood the fact that solutes affect solubility. Students'misunderstanding about the concept of dissolution resulted from the lack of the explanation on the right concept of dissolution in science textbooks and the inappropriate use of the dissolution model by teachers. In conclusion, we need the appropriate explanation in middle school science textbooks that consider the students'level and the development of the appropriate model that demonstrates dissolution in the perspective of particles.

• Journal of The Korean Association For Science Education
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• v.20 no.1
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• pp.155-165
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• 2000

The purpose of this study was to find out the degree of science problem solving by the information processing types and cognitive styles of 235 6th grade students. The results of this study were as follows. First, as the students got higher scores in the two types of information processing, they could solve more science achievement items and creative problem solving items correctly. And as the students got higher scores in simultaneous information processing test, they could solve more scientific concept understanding items. Secondly, as the students were more field-independent, they could solve more science achievement items and creative problem solving items. And especially in solving scientific concept understanding items, much higher field-independence was required. Finally, there was a significant difference on the distributions of cognitive styles by the information processing types. As the students got higher scores in the two types of information processing, their cognitive style tended to be more field-independent.

• BMB Reports
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• v.36 no.1
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• pp.43-48
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• 2003

Understanding the process of carcinogenesis will involve both the accumulation of many scientific facts derived from molecular, biochemical, cellular, physiological, whole animal experiments and epidemiological studies, as well as from conceptual understanding as to how to order and integrate those facts. From decades of cancer research, a number of the "hallmarks of cancer" have been identified, as well as their attendant concepts, including oncogenes, tumor suppressor genes, cell cycle biochemistry, hypotheses of metastasis, angiogenesis, etc. While all these "hallmarks" are well known, two important concepts, with their associated scientific observations, have been generally ignored by many in the cancer research field. The objective of the short review is to highlight the concept of the role of human adult pluri-potent stem cells as "target cells" for the carcinogenic process and the concept of the role of gap junctional intercellular communication in the multi-stage, multi-mechanism process of carcinogenesis. With these two concepts, an attempt has been made to integrate the other well-known concepts, such as the multi-stage, multi-mechanisn or the "initiation/promotion/progression" hypothesis; the stem cell theory of carcinogenesis; the oncogene/tumor suppression theory and the mutation/epigenetic theories of carcinogenesis. This new "integrative" theory tries to explain the well-known "hallmarks" of cancers, including the observation that cancer cells lack either heterologous or homologous gap junctional intercellular communication whereas normal human adult stem cells do not have expressed or functional gap junctional intercellular communication. On the other hand, their normal differentiated, non-stem cell derivatives do express connexins and express gap junctional intercellular communication during their differentiation. Examination of the roles of chemical tumor promoters, oncogenes, connexin knock-out mice and roles of genetically-engineered tumor and normal cells with connexin and anti-sense connexin genes, respectively, seems to provide evidence which is consistent with the roles of both stem cells and gap junctional communication playing a major role in carcinogenesis. The integrative hypothesis provides new strategies for chemoprevention and chemotherapy which focuses on modulating connexin gene expression or gap junctional intercellular communication in the premalignant and malignant cells, respectively.

• Journal of Korean Medical classics
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• v.30 no.4
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• pp.49-67
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• 2017

Objective : Heavenly stems and Earthly branches is a tool used for understanding the virtue of Yin Yang and Five elements. Korean medicine understands the changes in Wuyun through the Ten Heavenly stems, and understand the changes of Liuqi through the Twelve Earthly branches. An accurate understanding of the definitions of Heavenly Stems and Earthly branches and the concept of each of the 10 stems is of vital importance. Method : The paper first reviews the origin, history, and significance of the Heavenly stems and Earthly branches before studying the definitions of the stems and branches as laid out in the works of Yu Onseo, Lee Samun, and Han Dongseok. The paper then reviewed the concept of the each of the ten stems through researching the texts of Seoulmunhaeja, the annotations of the four great Seolmuns, and the texts of Jeongyeokwonui. Result & Conclusion : Heavenly stems and Earthly branches have been in use since more than 6,000 years ago. The central numbers in the changes of Heaven and Earth are five and six. Each number functions with duality, yin and yang, meaning there are ten Heavenly numbers ($5{\times}2=10$) and 12 Earthly numbers ($6{\times}2=12$) which oversees all of the cosmic changes. Stems become the body and signifies water. Branches become the use and signifies divided fire. The meanings of the letters Gab Eul Byeong Jeong Mu Gi Gyeong Sin Im Gye originate from the one year life of a tree which grows, bears fruits, processes Yang qi, and awaits for the next spring. The reason a tree is used is because there is nothing better in studying in detail the changes of a living being through a year.

• Journal of the Korean School Mathematics Society
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• v.23 no.3
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• pp.239-257
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• 2020

This study analyzes the degree of freedom with three aspects: as academic knowledge, in the curriculum focused on textbooks, and students' understanding of the degree of freedom. The results provide five critical points. First, we need discussions on whether to include the degree of freedom in the curriculum. Second, we need to reconsider the current way textbooks are described. Third, there should be a didactical analysis to advance students' understanding of the concept of the degree of freedom. Fourth, there are limitations in learning the concept of the degree of freedom in the current textbook learning environment. Fifth, a didactical check of sampling distribution such as sample mean, sample variance, and sample standard deviation is required. The implications were drawn that the emphasis on statistical reasoning education in the curriculum and careful consideration of introducing the t-distribution curriculum was required.

• Journal of the Korean Institute of Educational Facilities
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• v.4 no.3
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• pp.15-29
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• 1997

Open education started spontaneously in elementary school and accommodates positively as a result of educational reformation. Open education also contributes to the development of human nature. This developes a creative power and inhances independence according to a main task of school support for the 21st century. A premise of this study is how to fulfill a fresh and wide space field of learning which is an indispensable condition of open education. The study analysed the teachers' reactions to open education after classifying an atmosphere of reception, understanding concepts, and application. This examined the concept, basic principles, characteristics, teaching-learning activiters open education, and quality of learning. The method of research used was on the results from the percentages of questionnaires that were posted to the sample schools. Although the final outcome to open education can not be summarized, three preconclusions of open education are as follows; First an atmosphere of reception is spreading continuously day by day. Secondly, understanding the concept of open education is very important. Thirdly, go percent of all schools have experienced open education were applied to open education. Contrary to some affirmative reactions, there are some disadvantages to open education. incdule, poor educational environments, difficulty in managing schools, lack of repetition of old out-dated teaching skills. Finally in conclusion, we must learn to adapt to the new method of open education as our educational system for the 21st century can not simply rely upon the open education motto. Above all, we must support educational reform and enforce the development of education within the education act.

• Journal of Korean Medical Ki-Gong Academy
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• v.7 no.2
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• pp.134-145
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• 2004

Qi. in ancient east Asian Philosophy and medicine, was the quintessential concept symbolizing material orgin of the world. It was considered as the original matter of the world, and the genesis, development and extinction of everything in heaven and earth was explained through the movement of Qi. Despite its importance, the interpretation of Qi has brought about various bifurcations in the history of Oriental medicine. It is comprehended either as ideal concept, or as actual entity. Also, there exists synthetic idea of considering both sides of Qi. These ideas results from obscure understanding based on textual interpretation apart from actual experince. When experincing Qi through discipline, however, man can understand Qi concretly and actually and even grasp the explanation of the cosmos and life. One problem of Qi discipline was that it couldn't ascend the stage of subjective experience. Now, with the method of 'Hanalmomjit'. a developed form of zifadonggong(自發動功), I could reach coherent results to offer the foundation of objective understanding of Qi. The testees, disciples of Hanalmomjit, could express the characters of herbs in their Qigong actions, and the expression was meaningful and coherent to be considered as expressing the effects described in the classics of herbalogy. This result comes from the capacity of grasping external Qi-status, not only expressing the internal communication of jingluo(經絡) in Hanalmomjit.

• Journal of The Korean Association For Science Education
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• v.23 no.2
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• pp.176-188
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• 2003

Self-induction is an important concept in the field of electromagnetism, which is dealt with in all the high school physics textbooks. According to the results of the survey on self-induction, most of general high school students and even science high school students have overgeneralized concepts that high self-induced emf. are produced whenever the switch is turned off in the circuit containing inductors. The reasons of this overgeneralization on self-induction could be explained through the analysis of current high school physics II textbooks. Main reasons can be attributed to the fact that, by depending on their intuitive ideas, students try to vaguely explain the concept, based on lighting up of Ne tube in the special circuit. This study found out qualitative method to have students effectively understand self-induction based on quantitative interpretation to gain scientific understanding on self-induction.

• Education of Primary School Mathematics
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• v.20 no.2
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• pp.163-175
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• 2017

The purpose of the study is to identify the effect of length and right angle indication on the understanding of the concept of the figure when presenting the task of classifying the plane figures. we recorded thirty three 4th grade students' performance with eye-tracking technologies and analyzed the correct answer rate and gaze duration. The findings from the study were as follows. First, correctness rate increased and Gaze duration decreased by marking length in isosceles triangle and equilateral triangle. Second, correctness rate increased and Gaze duration decreased by marking right angle in acute angle triangle and obtuse triangle. Based on these results, it is necessary to focus on measuring the understanding of the concept of the figure rather than measuring the students' ability to measure by expressing the length and angle when presenting the task of classifying the plane figures.

• Journal of the Korean School Mathematics Society
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• v.19 no.4
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• pp.373-394
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• 2016

The "Figure Equation" chapter of current high school curriculum prevents students from relating the concept with what they studied in middle school Euclidean geometry. Woo(1998) concerns that the curriculum introduces the concept merely in algebraic ways without providing students with opportunities to relate it with their prior understanding of geometry, which is based on Euclidean one. In the present study, a sequence of GeoGebra-embedded-geometry lessons was designed so that students could be introduced to and solve problems of the Analytic Geometry by triggering their prior understanding of the Euclidean Geometry which they had learnt in middle school. The study contributes to the field of mathematics education by suggesting a sequence of geometry lessons where students could introduce to the coordinate geometry meaningfully and conceptually in high school.