• The Mathematical Education
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• v.44 no.4 s.111
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• pp.627-651
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• 2005

This study was conducted to attain an in-depth understanding of students' mathematical representations and to present the educational implications for teaching them. Twelve mathematical tasks were developed according to the six types of problems. A task performance was executed to 151 third graders from four classes in DaeJeon and GyeongGi. We analyzed the types and forms of representations generated by them. Then, qualitative case studies were conducted on two small-groups of five from two classes in GyeongGi. We analyzed how individuals' representations became elaborated into group representation and what patterns emerged during the collaborative small-group learning. From the results, most students used more than one representation in solving a problem, but they were not fluent enough to link them to successful problem solving or to transfer correctly among them. Students refined their representations into more meaningful group representation through peer interaction, self-reflection, etc.. Teachers need to give students opportunities to think through, and choose from, various representations in problem solving. We also need the in-depth understanding and great insights into students' representations for teaching.

• Proceedings of the Safety Management and Science Conference
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• 2003.05a
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• pp.291-297
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• 2003

In fact, some cases that successfully introduced CRM show that CRM is migrating from small scale which is typical when introduced to larger scale through various tests. The process also comprises all strategic planning, capital investments, management decisions, and tasks necessary to create a new product. manufacturing processes must be created so that the product can be produced in the product facility Therefore, this study tries to segment customer for the sieving the problem. And it make efficient customer management.

• Journal of Korean Elementary Science Education
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• v.31 no.1
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• pp.71-83
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• 2012

The purpose of this study was to explore ecological concepts, epistemological reasoning and reasoning processes through constructing 'food web and food pyramid' in ecology. We conducted classes which involved a 'food web and food pyramid' for $6^{th}$ grade students. Each class is constructed of small groups to do modeling and epistemological reasoning through communication. The researcher had videotaped and recorded each class and have made transcription about classes. We analysed patterns of 'food web and food pyramid models' and reasoning processes according to scientific epistemology using transcription data and student outputs. As a result, students represented phenomenon-based reasoning, relation-based reasoning and model-based reasoning in scientific epistemology from their modeling. Students usually did relation-based reasoning and model-based reasoning in food web which explains ecological phenonenon, while they usually did model-based reasoning in food pyramid which expects ecological phenomenon. Student's reasoning can be limited when they have misconception of scientific knowledge and are limited by fragmentary knowledge. This represents that students has to do relation-based reasoning and model-based reasoning is beneficial in their ecological model. It also suggests that students need to define correct-conception related to ecological modeling(food web, food pyramid).

• Journal of the Korean Geographical Society
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• v.29 no.3
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• pp.340-359
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• 1994

This study intends to describe the characteristics of the transformation of the rural society by tracing the changing social and economic processes of traditional clan villiage (Yeolmi-ri, Silchon-myeon, Kwangju-gun, Kyunggi-province) in the suburbs of Seoul Metropolitan Area. Rural society has experienced serious change of the social structure by the ever expanding urbanization and industrialization since 1960's. The suburbs of Seoul Metropolitan Area is the representative case area of such transformation. This study analyzed various chracteristics of population structure of a villiage, the processes of residential movement and the occupational shift of each household of the villiage in terms of household's life-history collected by interviewing with each household. And the whole households of a villiage is divided by two groups of the native clan group and the non-dan in-migrant group. The results of this study are summarized as follows. 1) This villiage is located within a lineal distance of 40km and a time distance of about 30 to 40 minutes, adjoined dy the Joongbu(중부) national highway, the Kyungchoong (경충) industrial road, the local road between Yangpyuna(양평) and Gonjiam(곤지암) and having a advantageous iocational linkage to Seoul capital city. 2) It is a typical traditional dan villiae constituted of dan family Gu(구) one of whose ancestors had appointed to the prime minister of Chosun Dynasty, and until 1979, 56 out of 60 families of the villiage households were clan families. 3) Since 1979, as the villiage invaded by the out-movement of the small scale manufacturing industries from Seoul capital city, labours moved in this vallige from outside and increased villiage size up to 203 households in 1993, consequently the constitutional proportion between the native clan group and the non-clan in-migrant group was reversed up to 28% vs 72% deepening the sociological heterogeneity. 4) Because of the small scale of industries in this villiage and the vicinity with the city of Seoul, the population turnover of this villiage is very high. The turnover frequency is firstly high within same administrative district of gun(군) level and secondly high between this villiage and the city of Seoul. Thus short-distance movement is identified. 5) There is a close correlation between the residential movement and the occupational shift. The most numbers of non-farm native group have the experiences of migration while the members of native farming group don't shift both the job and the place of residence. The inmigrant group had several migration experiences but few occupational shifts. Thus occupatioanl shift is high for the native group while residential shift is high for the in-migrant group. It is concluded that the change proceeded in Metropolitan suburbs was not directed to form the traditional rural village as 'gesund Gebiet' with respect to the ballance among the economic, cultural and environmental adequency.

• Applied Microscopy
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• v.22 no.1
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• pp.33-41
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• 1992

To clarify the exocytotic features in adrenal medullary aminergic cells, the authors observed rat adrenal medulla prepared by the TAGO method with transmission electron microscope. Rat adrenal medulla contains two types of aminergic cells, adrenergic and noradrenergic, as described. They were present as a group. In a single group both adrenergic and noradrenergic cells were present, but the same kind of cells showed the tendency forming small groups. Adrenergic cells were characterized with the granules having relatively electroluscent cores. These granules were relatively uniform in size, and the cores filled the granules with only thin halos. Noradrenergic cells were characterized with the granules of various size and forms. Most of the cores of these granules were generally more electron-dense than those of the adrenergic cells and only partly filled the granules without forming the halos. But, some granules were very similar in the shape and electron density as those of the adrenergic cells. Even empty-looking granules were present. Exocytotic figures with the classical omega figures were observed in both types of aminergic cells, but they were more frequent in adrenergic cells. These figures were mainly present along the plasma membranes toward the capillary. The excreted materials could be identified in the cleft of the omega figures. Apocrine-like secretory patterns but without cytoplasmic rims were identified in noradrenergic cells. Some vesicles, possibly formed from the cytoplsmic tubular systems were released. Some irregular lamellar structures of varying sizes were also observed. They looked like membranous structures sneaking through the plasma membranes. We could not, however, found any evidences of their involvement in exocytotic processes. These were present toward the capillaries and found only in the adrenergic cells. The authors conclude that the secretory processes in adrenal chromaffin cells may include not only the classical exocytotic processes but also the unusual direct secretions of granules or parts of cellular organelles. The membranous lamellar structures may indicate the remnants of excreted granules or functionally inactive excess membranes of the organelles removed from the cytoplasm.

• Journal of Science Education
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• v.37 no.1
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• pp.117-130
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• 2013

The purpose of this study was to analyze the patterns and features of interaction in teacher interviewing with high school students' small group for biology learning. The interactions in variety between the students and between the students and the teacher were made as the interviews with each small group were repeated to feedback for biology learning. The patterns of interaction were categorized into four types by interactive level of interaction among group members and a teacher: leader representation without interaction among students and the teacher(LR, leader representation), interaction among a part of students and the teacher(PSI, partial students interaction), active interaction among students inside the group, but only interaction between the teacher and the leader student(SAI, students active interaction), and interaction between all of the students and the teacher(teacher-students active interaction). Even though complex patterns of interactions were made among the students at the initial stage of insufficient understanding on the study concept, the simple interaction processes were shown as students had gradually completed the understanding on the concept. It was displayed that the interaction in the small group for biology study provides the opportunity to confirm and understand the concept to the students who were poor at the understanding on the concept, and it can influence positively on the mutual creation of study concept.

• Journal of Digital Convergence
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• v.6 no.4
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• pp.177-183
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• 2008

This paper aims to offer a solution based on intelligent document classification to create a user-centric information retrieval system allowing user-centric linguistic expression. So, structures expressing user intention and fine document classifying process using EBL, similarity, knowledge base, user intention, are proposed. To overcome the problem requiring huge and exact semantic information, a hybrid process is designed integrating keyword, thesaurus, probability and user intention information. User intention tree hierarchy is build and a method of extracting group intention between key words and user intentions is proposed. These structures and processes are implemented in HDCI(Hybrid Document Classification with Intention) system. HDCI consists of analyzing user intention and classifying web documents stages. Classifying stage is composed of knowledge base process, similarity process and hybrid coordinating process. With the help of user intention related structures and hybrid coordinating process, HDCI can efficiently categorize web documents in according to user's complex linguistic expression with small priori information.

• Journal of Korean Elementary Science Education
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• v.34 no.3
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• pp.346-356
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• 2015

The purpose of this study was to explore the characteristics of elementary science gifted students' modification of scientific explanations based on evidences. For this study, sixteen $6^{th}$ elementary students were participated. The subjects of this study were enrolled in the program for the science gifted. Students were asked to generate initial hypotheses before experiment, and to modify and revise their scientific explanations based on the experiments about water rising in burning candle(s). All the processes of small group discussion during the inquiry were audio-recorded. Students' modification of their scientific explanations were appeared in three types: 1) appropriate connections among evidences, reasoning, and claims, 2) disconnections among evidences, reasoning, and claims and/or use of inappropriate reasoning, 3) scientific explanations without their own understanding. Other problems that students encountered in the processes of modification of their explanations were also discussed.

• The Mathematical Education
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• v.53 no.2
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• pp.275-290
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• 2014

This study investigated the types of the 3D geometric thinking and spatial reasoning through the observation of the 2D representing activities for representing the 3D geometrical objects with preservice secondary mathematics teachers. For this purpose, the 43 sophomoric students in college of education were divided into 10 groups and observed their group task performance on the basis of the representation they used. Observed processes were all recorded and the participants were interviewed based on the task. As a result, the role of physical object that becoming the object of geometric thinking and spatial reasoning, and diverse strategies and phenomena of the process that representing the 3D geometric figures in 2D were discovered. Furthermore, these processes of representing were assumed to be influenced by experience and study practice of students, and various forms of representing process were also discovered in the process of small group activities.

• Carbon letters
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• v.14 no.2
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• pp.89-93
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• 2013

Size-sorted graphene nanoplatelets are highly desired for fundamental research and technological applications of graphene. Here we show a facile approach for fabricating size-sorted graphene oxide (GO) nanoplatelets by a simple centrifugal method using different dispersion solvents. We found that the small-sized GO nanoplatelets were more effectively separated when dispersed in water or dimethylformamide (DMF) than in an alkali aqueous solution. After several iterations of the centrifugation, the sizes of GO in the supernatant solution were mostly several micrometers. We found that the GO area was not strongly correlated with the C-O content of the GO dispersed in water. However, the size-sorted GO nanoplatelets in DMF showed different C-O content, since DMF can reduce GO nanoplatelets during exfoliation and centrifugation processes.