• Environmental Analysis Health and Toxicology
• /
• v.24 no.1
• /
• pp.17-23
• /
• 2009

Nanotechnology, one of the technologies that forms the core of the recent scientific innovation, is used much in our real lives. Especially products that use nano silver are being sold, with its positive characteristics resulting from the antibacterial effects of both nano materials and silver. But critiques have pointed out that nano silver diffused into everyday life too quickly as we do not have done any comprehensive research about the material, and worry that nano silver will affect the ecology adversely. Therefore, this research focuses on investigating the toxicity of silver nanoparticles first. To compare the effects of exposure to silver nanoparticles at pre-somite stage and somite stage(10 hours after fertilization), we exposed zebrafish embryos to silver nanoparticles(15, 30 ppt) during embryogenesis, and then checked the details of catalase enzyme activity. The hatch rate decreased in the silver nanoparticles exposed groups(15 and 30 ppt); furthermore, the hatched fishes had an abnormal notochord, damaged eyes and curved tail. The catalase activities of the 15 ppt exposed group at somite stage increased relative to those in the control group. Therefore, the silver nanoparticles could seriously damage the development of zebrafish embryos. Especially, exposure to silver nanoparticles at somite stage did severer damage than exposure since pre-somite stage did.

• Journal of Korean Society of Archives and Records Management
• /
• v.16 no.3
• /
• pp.69-97
• /
• 2016

For a long time, popular songs have been our source of happiness. They go along with the flow of the generation, allowing them to acquire a significant meaning. Popular songs thus reflect the contemporary society. However, in the study of popular song archives, there has been an interest only in the information of the songs sung by a singer, the type of songs, and the type of singers. Thus, existing popular song archives were not able to reflect the characteristics of the society of the generation when the songs were popular. Therefore, this paper searched for ways by which to archive not only popular songs but also the characteristics of the society during the time when these songs were famous, and suggested a story collection through the methods. These stories reflect the lives of the people and the characteristics of the society during the periods when the songs were popular. Furthermore, these stories go beyond popular songs, making it possible for us to look dimensionally on the society we are affiliated in.

• Journal of Digital Convergence
• /
• v.16 no.10
• /
• pp.27-37
• /
• 2018

The purpose of this study is figure out secondary education undergraduates' communication patterns and perceptions of use in KAKAOTALK, one of the most frequently used Social Network Service(SNS). The mixed method research was conducted of survey about 86 students and in-depth interview 10 of them. The chief implication of research showed that it has been firstly functioning them to sustain public and private network and to be an universal tool of expression their opinion, idea, themselves, however, they still regard face-to-face communication important. Secondly, they think that KAKAOTALK is a part of their everyday lives and regarded a communication space to freely express themselves and to adjust and manage their image. Thirdly, they psychologically solved their loneliness and were encouraged, moreover, the contents of communication were different according to usd of public or private team chat room. It needs a follow-up study comparatively to analyze other generation's cognitive psychological values in SNS and to suggest digital culture literacy guideline.

• Composites Research
• /
• v.28 no.6
• /
• pp.378-382
• /
• 2015

With increasing population density and high-rise expansion of buildings in recent years, elevators have become to play a pivotal role in our everyday lives as most people take an elevator several times even in a day. The elevator penetration and distribution rates in Korea have increased dramatically every year, and the emergence of skyscrapers leads to accelerating the development of elevator industry. Carbon-fiber-reinforced plastics (CFRPs) exhibit better mechanical and thermal properties than steel suitable for uses as elevator wire ropes. In this paper, in order to analyze the properties of CFRPs, the tensile strength of unidirectional (UD) CFRP wire ropes was characterized and finite element analysis was conducted for bending simulation. Simulation results were compared.

• Annals of Clinical Neurophysiology
• /
• v.5 no.1
• /
• pp.16-20
• /
• 2003

Background: Mobile phone has become a very popular device used in everyday our lives. However, the possible hazard to human body such as brain tumor has been proposed intermittently. This unwanted possibility was calmed down due to the absence of definite evidence of hazard. This study was performed to see the effect of mobile phone use on the brain temperature. Methods: In 20 volunteers, we performed 4 steps of temperature measuring procedure. Four steps are pre-use (S1, basal state), wire-phone (S2, conventional telephone), PCS phone (S3, using 1,750~1,900 MHz), cellular phone (S4, using 820 MHz) states. Brain temperatures were measured by radiothermometer at 10 sites (5 sites in each hemisphere) of the brain after 5minutes of telecommunication through the phones. The final data were compared using paired t-test. Results: In PCS phone user group (Average; $35.73708^{\circ}C$), brain temperature decreased (with statistical significance, p<0.05), compared to those of non-user group (Average; $35.9527^{\circ}C$) or conventional wire phone user group. In cellular phone user group (Average; $35.82155^{\circ}C$), brain temperature decreased slightly (without statistical significance, p>0.05) compared to those of non-user group (Average; $35.9527^{\circ}C$) or conventional wire phone user group (Average; $35.922^{\circ}C$). The temperature change was not limited to the mobile phone applied side but on both hemisphere of the brain. Conclusion: In conclusion, mobile phone (especially PCS phone) decreased brain temperature in both hemispheres without side-to-side temperature difference. In addition, this study suggests possibility of radiothermometer application to the study of electromagnetic wave effect and protection method research in the future.

• Journal of Digital Convergence
• /
• v.12 no.10
• /
• pp.509-514
• /
• 2014

It is said that ceramic arts which reflects the sprit of the age and culture is one of the representative cultural assets in Korea. Ceramic arts has the longest tradition and it has been used in our everyday life from a historical perspective. Unfortunately, most textbooks we use nowadays just show some art works for appreciation. It is impossible to teach unique techniques of ceramic arts with those textbooks. Traditional culture is not considered as a main part of educational contents but surrounding elements. Therefore it is hard for students to learn about our traditional culture deeply and it is also difficult to know the importance of the ceramic arts in secondary schools. Through the education of ceramic arts students can understand our traditional culture and they can also experience the formative arts by using plane and dimensional techniques. Teachers have to focus on historical background, types, functions, and sense of beauty of ceramic arts when they teach students in school. Students can use the knowledge in their daily lives. The education of ceramic arts encourage students to create new culture for ceramic arts.

• Convergence Security Journal
• /
• v.19 no.3
• /
• pp.81-86
• /
• 2019

This study introduces trends on silver care implemented with the fourth industrial revolution technology, and discusses the use of digital technology for elderly health and rehabilitation by reviewing relevant literature to examine and present directions for future digital-based silver care commercialization. First, health smart home, which is a smart residential service available through digital technology or IT technology that supports independent living in your home, is available. Second, there are technical services using artificial intelligence(AI) and robots. Robots based on advanced intelligence can serve as an assistant for the health and rehabilitation of senior citizens by supporting services that enable the daily lives of senior, checking their health conditions, and high-quality medical care. For the commercialization of these silver care systems, information and services appropriate to the current situation, such as the physical ability and health status of the elderly, should be provided, and it would be desirable to gradually expand the use of essential technology to reflect the needs of the elderly in use so that the digital alienated.

• Journal of Korean Elementary Science Education
• /
• v.31 no.1
• /
• pp.109-124
• /
• 2012

Developing pedagogical content knowledge (PCK) has been emphasized for teacher's professionalism and it should be done from systematic teacher training courses. In this study, we investigated changes of elementary pre-service teachers' PCK of science teaching and motivational strategies before and after a training course. For the analysis of pre-service teachers' PCK, their lesson plans, surveys, and interviews were collected. According to the results, in the beginning of the semester, pre-service teachers in the experimental group usually used didactic or combination of didactic and inquiry teaching strategies and a few pre-service teachers used inquiry or discovery teaching strategies when making lesson plans. However, at the end of the semester many pre-service teachers used inquiry teaching strategies in their lessons which included activities of asking students' prior knowledge, conducing experiments, finding conclusion, and comparing teachers' explanations with students' explanations. Regarding motivational strategies, in the beginning of the semester they focused using activities to create student's emotional interest in science lesson but at the end they used other strategies to create positive atmosphere for learning, capture intellectual interest in science, and connect science to students' everyday lives. The changes in pre-service teachers' PCK in the experimental group was meaningful because there was less change in pre-service teachers' PCK in the control group. This study implies the need for effective professional development programs for developing pre-service teachers' PCK.

• Human Ecology Research
• /
• v.51 no.3
• /
• pp.355-370
• /
• 2013

The purpose of this study is to investigate the nature of work-family compatibility in the everyday experiences of dual-earner families. By comprehensively describing how dual-earner families manage daily life, this study shows their current situations. In particular, this study overcomes the limitations of previous studies using the phenomenological research methods. Previous studies partially dealt with the problems of dual-earner couples, such as the role conflict of wives and husbands. However, this study broadly demonstrates how wives and husbands as independent individuals manage their lives by working together for a living. Participants were 6 males and 6 females, who lived in Gwangju metropolitan city. Data were collected through in-depth interviews and analyzed using the method of Stevick-Colaizzi-Keen in Moustakas (1994). The results of this study display that dual-earner couples work for a living, but work is the driving force in their life. Family provides dual-earner couples with a stable life, but their stable life is possible by social support like the assistance of a mother-in-law. Dual-earner couples consider work and family as the essential axis of life, thus they give the same value on work and family. Even though dual-earner couples have a difficult time educating their children because of long working hours and coming home late, they positively combine work and family meeting the needs of self-improvement. Therefore, it is necessary to create a working environment that provides enough time for housework and childcare.

• Journal of Educational Research in Mathematics
• /
• v.10 no.1
• /
• pp.35-55
• /
• 2000

There seems to be a public consensus that the content of Korean mathematics textbooks is extensive and of a high level of difficulty. However, such judgment is the result of a generalization based on individual experience or on the results from comparisons of the international levels of achievement. Therefore, a more objective and stricter approach to the determination of the quantity and level of difficulty of mathematics content is necessary. For this purpose, this study has compared the content of Koreas 6th and 7th junior high school curriculums, and the Korean mathematics curriculum to textbooks of the United States, which has a considerable influence on the making of Korean mathematics textbooks. First of all, a comparison of Koreas 6th and 7th junior high school mathematics curriculums showed a slight reduction in the total quantity of content, as more content was deleted than was added in the 7th curriculum. However, given the fact that the number of hours of mathematics classes has been reduced, the reduction in content cannot be regarded as anything more than a simple reflection of the reduction in hours, proving that the 7th curriculum has not met its revision objective of reducing the content by 30%. Meanwhile, the comparison of the United States junior high school mathematics textbooks to Korea's 7th curriculum showed that the 7th grade content in the United States was much broader, encompassing content which in Korea ranged from the 2nd grade of elementary school to the 2nd year of junior high school. Therefore, on the surface, it may appear that the overall level of content in the American mathematics textbook is lower than that of the Korean. However, there are several cafes, such as statistics and probability, where certain content was more difficult and introduced at an earlier grade in the United States than in Korea. In fact, it can be said that Korea students tend to find content of the mathematics textbooks to be harder than they actually are because they are delivered as a mere aggregate of algorithms, with little consideration to its application in their everyday lives. In this respect, there is much room for improvement on the mathematics textbooks of Korea.