• Journal of Periodontal and Implant Science
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• 제40권3호
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• pp.111-118
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• 2010

Purpose: The aim of this study was to investigate whether vitrification in the cryopreservation of periodontal ligament (PDL) cells could be useful for tooth banking. Methods: In step 1, primary cultured human PDL cells were cryopreserved in 100% conventional cryopreservation media and 100% vitrification media (ESF40 media) in different temperatures for 2 weeks. In step 2, a series of modified vitrification formulae named T1 (75% vitrification media + 25% F-media), T2 (50% vitrification media + 50% F-media) and T3 (25% vitrification media + 75% F-media) were used to store PDL cells for 2 weeks and 4 weeks in liquid nitrogen. MTT assay was performed to examine the viability of PDL cells. Results: Maximum cell viability was achieved in cells stored in 100% conventional cryopreservation media at $-196^{\circ}C$ (positive control group) in step 1. Compared to the positive control group, viability of the cells stored in 100% vitrification media was very low as 10% in all test conditions. In step 2, as the percentage of vitrification media decreased, the cell viability increased in cells stored for 2 weeks. In 4-week storage of cells in step 2, higher cell viability was observed in the T2 group than the other vitrification formulae while the positive control group had the highest viability. There was no statistically significant difference in the cell viability of 2-week and 4-week stored cells in the T2 group. Conclusions: These observations indicate 100% vitrification media is not successful in PDL cell cryopreservation. Conventional cryopreservation media is currently the most appropriate media type for this purpose while T2 media would be interesting to test for long-term storage of PDL cells.

• 아동학회지
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• 제38권1호
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• pp.77-93
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• 2017

Objective: The purpose of this study was to develop a text-based media literacy program and to examine its effects on young children's understanding and expression of media text. Methods: The participants were 54 5-year-old kindergarteners assigned to an experimental or a control group, with 27 children per group. The text-based media literacy program was based on the ADDIE model and was administered to the experimental group for 8 weeks. The pre- and post-test instruments measured media text understanding and expression ability and were patterned after those used by British Film Institute (2003) and other major studies. Results: The experimental group showed higher levels of media text understanding and expression than the control group. Conclusion: The results are discussed with respect to their implications for educational practice and future research.

• International Journal of Contents
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• 제12권4호
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• pp.69-75
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• 2016

Adolescent media addiction has emerged as an important social agenda in Korea. However, there has not been enough discussion on the causal structure of media addiction and policy interventions. The objective of this study is to identify and assess the mechanism of the existing and the revised Shutdown policy based on the systems thinking approach. To achieve this purpose, we establish the relationship between media usage, flow, and addiction, and develop a causal loop diagram. Based on the causal loop diagram, we explore the causal structure of two policy scenarios: shutdown policy and deregulation. Our study suggests that policy interventions inducing direct parental control on children's media usage time are ineffective since the time control reduces children's autonomy, which helps alleviate media addiction. Therefore, this study suggests that policy intervention should focus on alleviating addiction itself rather than on controlling media usage time.

• 한국정보과학회논문지:소프트웨어및응용
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• 제31권10호
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• pp.1356-1363
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• 2004

본 논문에서는 미디어 컨텐츠를 직관적으로 조작할 수 있는 새로운 형태의 감각형 미디어 제어 시스템(TMCS: Tangible Media Control System)을 제안한다. 현재 대부분의 사용자들은 키보드와 마우스를 사용하여 디지털 미디어 컨텐츠를 접하고 있으나 이는 사용자가 미디어 컨텐츠를 조작하는 데 있어서 직관적이지 못한 단점을 가진다. 제안된 시스템은 키보드와 마우스를 대신하여 일상 생활의 오브젝트에 RFID 태그와 트래커를 내장시킨 감각형 오브젝트를 이용하여 사용자가 직관적으로 미디어 컨텐츠를 접근하고 제어할 수 있는 감각적인 인터페이스를 제공한다. 그리고 사용자의 기호에 따라 미디어 컨텐츠들을 합성하거나 조작할 수 있는 기능을 제공함으로써 미디어 컨텐츠와 다양한 상호 작용을 지원한다. 또한 사용자 및 상황 정보를 이용하여 사용자의 기호에 따른 개인화 된 미디어 컨텐츠를 제공함으로서 사용자의 욕구를 충족 시켜 줄 수 있는 환경을 제공한다. 더 나아가 이러한 장점을 기반으로 하여 인터렉티브 멀티미디어 재생기 및 제작기, 그리고 멀티미디어 기반의 교육 및 오락 프로그램 등 다양한 분야에 적용할 수 있다.

• 한국응용과학기술학회지
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• 제2권2호
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• pp.15-20
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• 1985

Influence of vitamins on the felt and lipid production of Aspergilus niger var. macrosporus, Aspergillus fumigatus and penicillium notatum were investigated after 10 days of incubation at $30^{\circ}C$ under static culture condition. The felt of molds were lower in the media containing vitamins than control medium. The lipids produced by each strains were highest yields in media containing vitamins. Among of these Aspergillus niger var. macrosporus and Aspergillus fumigatus produced. 4.6g and 5.28g in medium containing inositol 2.5mg/l and 0.5mg/l, respectively; while Penicillium notatum produced 1.51g in a medium containing thiamine 10mg/l. The major fatty acid of lipids were palmitic acid, stearic acid, oleic acid and linoleic acid. Aspergillus niger var. macrosporus was lower palmitic acid in media containing vitamins than control medium, While linoleic acid was higher in media containing thiamine and inositol. Aspergillus fumigatus was lower oleic acid in media containing vitamins than control medium, While linoleic acid was higher in media containing vitamins. Peniillium notatum was lower palmitic acid, oleic acid and stearic acid in media containing vitamins but linoleic acid was higher. The composition of fatty acid of lipids changed depending on the media containing vitamins but hardly found a certain tendency except linoleic acid which was higher in a media containing thiamines and inositols. The degree of unsaturation of fatty acids in the lipids were comparatively higher in media containing vitamins than control medium.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 춘계학술대회 논문집
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• pp.1125-1130
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• 2005

This paper presents a method for inter-sheet spacing control in a flexible media handling device. In order to verify the performance of inter-sheet spacing control by experiment, system of section structure is introduced in the first place. In the introduced system, each section is driven by different servo motor for independent section freedom. And suitable inter-sheet spacing control algorithm that is more optimal than conventional inter-sheet spacing control algorithm is proposed. Finally experiments are performed to confirm the performance of inter-sheet spacing control. And two inter-sheet spacing control algorithms, conventional and proposed, are compared with each other.

• Journal of Nutrition and Health
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• 제29권1호
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• pp.97-103
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• 1996

This study was performed to investigate the effects of lipid on cellular senescence, lipid peroxide production, and morphological changes. For this study we used primary skin fibroblasts from neonate rats grown in media various lipid contents. Fibroblasts were cultured until they lost their proliferation potential either in control medium (Dulbecco's modified Eagle's medium supplement with 10% fetal bovine serum) or in media supplemented with various concentrations of lipid-cholesterol rice component from bovine serum. Cumulative population doublings(CPD, as an index of cellular life span), and cellular thiobarbituric acid reactive substances (TBARS, as an index of lipid peroxide) concentrations were measured and morphological changes were observed. CPD were shortened with increasing lipid concentration in media ; 28.12 for cells grown in control medium and 13.42, 11.42, and 6.19 for those grown in 0.1%, 1% and 5% lipid rich components containing media, respectively. Cellular proliferation ratios were those grown in 5% lipid rich components containing media were delayed and they were degenerated soon. TBARS concentrations were increased with increasing concentration of lipid in media. Morphological changes were observed in cells grown in control medium by cellular senescence. Especially lipid droplets were observed in cells grown in 5% lipid rich components containing media. Therefore it seems that lipid contents in media had an effect on cellular proliferation and cellular life span, possibly via lipid peroxide production.

• 한국학교보건학회지
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• 제28권3호
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• pp.229-238
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• 2015

Purpose: This study was aimed to examine the effects of sexual education programs focusing on media literacy on teachers as a pilot study. Methods: This study is a quasi-experimental study and a total of 81 teachers (intervention n=42, control n=39) participated. Results: A sexual education program focusing on media literacy was conducted in the form of an 18-hour structured education module. The results were mainly assessed by measuring the teachers' pre- and post-study awareness and self-efficacy related to sexual media literacy. Awareness related to sexual media literacy of the intervention group (86.3) showed greater improvement than that of the control group (76.8). Also, self-efficacy related to sexual media literacy among the intervention group (20.1) showed greater improvement than that of the control group (17.4). Conclusion: The results highlight the effects of sexual education programs focusing on media literacy, which can improve teachers' competence in sexual education.

• 방송공학회논문지
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• 제10권4호통권29호
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• pp.548-556
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• 2005

무선 네트워크 환경은 채널의 페이딩 현상 및 채널 잡음으로 인해 다량의 패킷 손실 및 전송 지연의 변동이 유발되며 이는 스트리밍 미디어의 급격한 화질 열화를 발생시킨다. 이러한 채널 변동이 심한 무선 네트워크 환경에서 성공적으로 미디어를 전송하기 위해서는 유동적이고 네트워크에 적응적인 전송 기법이 필요하다. 따라서 본 논문에서는 무선 채널의 변동에 적응적이고 패킷 손실을 최소화하는 패킷 단위 interleaved FEC와 delay-constrained ARQ로 이루어진 응용계층 레벨에서의 네트워크적응형 전송오류 제어 기법을 제안한다. 또한 제안 기법을 포함한 각종 전송오류 제어 (혼합) 기법들을 검증하기 위해 시뮬레이션 툴을 개발하였다. 이를 통해 전송 계층에서의 전송오류 제어 성능을 확인하고, 전송되는 영상에 대한 객관적인 품질 평가를 진행한다. 진행된 시뮬레이션 결과를 통해 제안된 전송오류 제어 기법이 전송 계층에서의 전송오류 제어 성능을 향상시키며, 나아가서 전송되는 영상의 품질을 개선함을 확인한다.

• 대한가정학회지
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• 제44권7호
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• pp.73-83
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• 2006

This paper is focused on culinary practice. The objective of this research was to develop Instructional Media for efficient culinary practice at high school. For evaluation, Instructional Media were developed and used for culinary practice at a high school located in Chunan. Understanding, interest and scholastic achievement in culinary practice were evaluated and compared for the study group using the developed Instructional Media and the control group not using the developed Instructional Media. Understanding (p<.001), interest (p<.01) and scholastic achievement(p<.01) were higher in the study group than in the control group. The important contributions of this research include the reduction of practice time and improvement of scholastic achievement. The Instructional Media developed in this research will increase the students' interest, reduce the difficulties of culinary practice, and improve the students' culinary skill. The study and development of culinary practice is limited to CDs and illustrated books, and research on the development of various Instructional Media will continue.