• Journal of Korean Neurosurgical Society
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• v.45 no.2
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• pp.81-84
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• 2009

Objective : Many biomechanical and clinical studies on adjacent segment degeneration (ASD) have addressed cranial segment. No study has been conducted on caudal segment degeneration after upper segment multiple lumbar fusions. This is a retrospective investigation of the L5-S1 segment after spinal fusion at and above L4-5, which was undertaken to analyze the rate of caudal ASD at L5-S1 after spinal fusion on and above L4-5 and to determine that factors that might have influenced it. Methods : The authors included 67 patients with L4-5, L3-5, or L2-5 posterior fusions. Among these patients, 28 underwent L4-5 fusion, 23 L3-5, and 16 L2-5 fusions. Pre- and postoperative radiographs were analyzed to assess degenerative changes at L5-S1. Also, clinical results after fusion surgery were analyzed. Results : Among the 67 patients, 3 had pseudoarthrosis, and 35 had no evidence of ASD, cranially and caudally. Thirteen patients (19.4%) showed caudal ASD, 23 (34.3%) cranial ASD, and 4 (6.0%) both cranial and caudal ASD. Correlation analysis for caudal ASD at L5-S1 showed that pre-existing L5-S1 degeneration was most strongly correlated. In addition, numbers of fusion segments and age were also found to be correlated. Clinical outcome was not correlated with caudal ASD at L5-S1. Conclusion : If caudal and cranial ASD are considered, the overall occurrence rate of ASD increases to 50%. The incidence rate of caudal ASD at L5-S1 was significantly lower than that of cranial ASD. Furthermore, the occurrence of caudal ASD was found to be significantly correlated with pre-existing disc degeneration.

• The Mathematical Education
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• v.53 no.1
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• pp.147-162
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• 2014

The purpose of this study was to investigate the nature of pre-service elementary teachers' metaphors on mathematics textbooks. Their metaphors describe individual and collective patterns of thinking and action on mathematics teaching and learning. To analyze their metaphors, qualitative analysis method based on Lakoff and Johnson's theory of metaphor (1980) was adopted. Metaphors on mathematics textbooks were elicited from 161 pre-service elementary school teachers through writing prompts. The writing prompt responses revealed three types and thirteen categories: As Type I, there were (1) 'Principles', (2) 'Summary', (3) 'Manual', (4) 'Encyclopedia', (5) 'Code', (6) 'Guidelines', and (7) 'Example'. As TypeII, there were (9) 'Assistant', (10) 'Friend', (11) 'Scale', and (12) 'Ongoing'. As TypeIII, there was (13) 'Trap'. Among these categories, 'Guidelines', 'Assistant', and 'Ongoing' were the most frequently revealed. These results indicate that the relations of mathematics curriculum, textbooks, and classrooms are not a unilateral way but should communicate with each other.

• KIEAE Journal
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• v.12 no.3
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• pp.61-67
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• 2012

The purpose of this study was to analyze the characteristics of the pre-design of brownfield's by comparing LDA, EPA, and BRA of UK and USA in terms of establish mainbody, brownfield information, development process, opening development information. Such analysis will generate important implications for the development and renewal of brownfield in Korea by gaining insights into the characteristics of brownfield that reflect systematic and effective management and planning for urban renewal. The findings from this study indicate that: 1. Information on brownfield plays an important role at the development and planning stages that precede architectural design. 2. There is a great need for organizations that are responsible for brownfield renewal, such as LDA of UK, EPA and BRA of USA, in Korea, to make information public and to practice systematic management. 3. Discussion on the pre-design that follows contamination and renewal of brownfield and the developmental strategies that satisfy both the developmental and public profits are warranted.

• Journal of the Korean Society of Costume
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• v.56 no.6 s.105
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• pp.145-152
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• 2006

Dyeing properties of sargent cherry of Prunus sargentii Rehder were investigated with silk fabrics. The absorbed wave lengths at UV-VIS spectrometer were 362nm, 386nm, 430nm, and 512nm. The K/S value showed high in following conditions: 100%(w/w) stock solution, 60 minutes of dyeing time, 80$^{\circ}C$ of dyeing temperature, and 5 times of dyeing repetition. The K/S value showed higher in post-mordant than in pre-mordant, and the change of color did not appear in pre-mordant samples. They were colored greenish yellow in post-mordanted Cu and Fe. The highest dyeability and $\Delta$E showed in post-mordanted Fe. The light fastness showed 3-4 in post-mordanted Fe, 1-2 in pre-mordanted Al, and washing and perspiration fastnesses showed also good results in post-mordanted Fe.

• The Journal of the Convergence on Culture Technology
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• v.8 no.6
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• pp.9-22
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• 2022

The purpose of this study was to provide basic data on pre-service teacher's education based on cooperative learning-oriented teaching and learning methods by applying cooperative learning to verify the effectiveness of pre-service early childhood teacher's communication and problem-solving ability. In the first semester of 2021, 4th grade students who took the teaching method by subject class opened by department of early childhood education at C university were taught for 11 weeks from March 1st week to May 2nd week in 2021 for 4 hours a week. The results of this study were as follows: First, the average score of interpretive ability was the highest in the sub-areas of communication ability of pre-service early childhood teachers, followed by message conversion ability, role performance ability, self-presentation ability, and goal setting ability in the cooperative learning-oriented teaching method by subject class. Second, in terms of the overall average score of pre-service teacher's problem-solving ability, the average score of post-test was increased compared to the average score of pre-test. Through the cooperative learning-oriented class experience in the university's early childhood teacher training course, it is possible to cultivate the practical ability that can be used variously for the children such as communication ability and problem-solving ability in the early childhood education field. Therefore, it is necessary to provide opportunities for cooperative learning-oriented teaching methods in the teacher's education curriculum.

• The Mathematical Education
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• v.45 no.1 s.112
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• pp.75-96
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• 2006

The purpose of this study was to analyze how elementary pre-service teachers learned the pedagogical content knowledge of mathematics and to understand the challenges and difficulties that they experienced in the course of student teaching. A qualitative case study provided an in-depth description of the whole three weeks of student teaching process. Four pre-service teachers and two mentor teachers participated in this study. Multiple data collection techniques were used; classroom observations, in-depth interviews, document analysis, and researcher's field notes. The results of this study showed how pre-service teachers learn PCK of mathematics in designing mathematics lessons, understanding mathematics learners and delivering mathematics lessons and what are the difficulties and challenges they experienced. Finally this study discussed about some suggestions to pre-service program and future research.

• Korean Journal of Human Ecology
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• v.19 no.4
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• pp.625-639
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• 2010

This study compared male and female university students' perceptions of parenthood and their need for pre-parental educational program. Responses of 579 university students in 5 universities were collected using a questionnaire developed by the researchers. Data were analyzed using a T-test and Pearson's chi squared test. Results showed that (1) systematic and pre-parental education may increase opportunities for university students to prepare parent and child rearing skills. (2) Any pre-parent educational program developed should cover practical and such as communication skills, child-rearing techniques and ways of disciplining children. In this way an educational program could provide university students suitable guidance and give them a positive and proper attitude toward parenting should they become parents in the future.

• Journal of the Semiconductor & Display Technology
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• v.9 no.1
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• pp.11-16
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• 2010

Wafer Pre-Alignment is to find the center and the orientation of a wafer and to move the wafer to the desired position and orientation. In this paper, an area camera based pre-aligning method is presented that captures 8 wafer images regularly during 360 degrees rotation. From the images, wafer edge positions are extracted and used to estimate the wafer's center and orientation using least squares circle fitting. These data are utilized for the proper alignment of the wafer. For accurate alignments, camera calibration methods using high order polynomials are used for converting pixel coordinates into real-world coordinates. A complete pre-alignment system was constructed using mechanical and optical components and tested. Experimental results show that alignment of wafer center and orientation can be done with the standard deviation of 0.002 mm and 0.028 degree, respectively.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.375-376
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• 2008

The flashover of insulators in vacuum is the main factor to limit the performance of insulation in vacuum insulation system. It is believed that the pre-flashover phenomena would play a very important role in the procedure of the flashover in the interface between the insulators and vacuum. This paper is mainly concerned on the pre-flashover phenomena of Alumina insulators in vacuum. There are 24 different types of alumina insulators were tested with a 0.7/4 ${\mu}s$ pulsed voltage under a $1\times10^{-4}$Pa vacuum. The observed pre-flashover phenomena were classified and the pre-flashover characteristics were concluded. It is useful to study further on the flashover mechanism in vacuum.

• Journal of the Semiconductor & Display Technology
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• v.9 no.3
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• pp.47-51
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• 2010

This paper presents a wafer pre-alignment system which is improved using the image of the entire wafer area. In the previous method, image acquisition for wafer takes about 80% of total pre-alignment time. The proposed system uses only one image of entire wafer area via a high-resolution CMOS camera, and so image acquisition accounts for nearly 1% of total process time. The larger FOV(field of view) to use the image of the entire wafer area worsen camera lens distortion. A camera calibration using high order polynomials is used for accurate lens distortion correction. And template matching is used to find a correct notch's position. The performance of the proposed system was demonstrated by experiments of wafer center alignment and notch alignment.