• 한국초등과학교육학회지:초등과학교육
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• 제33권2호
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• pp.217-230
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• 2014

This study explores the features of sociocultural context of experiment classes taught by a science subject teacher. Two experiment classes on electric circuit for fifth graders were observed and video recorded. The data was also collected through student interviews and teacher interviews. Using the cultural historical activity theory, we extracted the six sociocultural factors and analyzed their interactions. This study could identify that four features of the sociocultural context of the cases. First, the rules of science classes were not decided by the teacher, but formed and modified through the negotiation between the teacher and students or between the students. Second, elementary students played a game, i.e. 'Countdown game', during their electricity experiments, which had both positive and negative influences on science learning. Third, the science teacher feels a limit on life guidance because of the position as a subject teacher in an elementary school. Lastly, although the science teacher had enough time to prepare science classes, there was no guarantee of the improvement of teaching quality. Based on the results of this study, educational implications are discussed in terms of teaching science experiments and of the science subject teacher system.

• Journal of the Korean Data and Information Science Society
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• 제23권6호
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• pp.1093-1102
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• 2012

본 연구에서는 다변량시계열모형인 VAR (vector autoregressive regression)모형에 의하여 금리 스프레드의 시계열예측을 수행하였다. 국내외 거시경제변수들 중에서 교차상관분석 및 그랜져인과 검정을 통하여 상호간에 설명력이 있는 변수들을 추출하여 VAR모형의 시계열변수로 사용하였다. 마지막 12개월의 예측치에 대한 MAPE (mean absolute percentage error)와 RMSE (root mean square error)에 근거하여 모형의 예측력을 단일변량 시계열모형인 AR (autoregressive regression) 모형과 비교하였다.

• 한국과학교육학회지
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• 제35권4호
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• pp.773-790
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• 2015

Conducted as an ethnographic examination of science teaching and learning in an Innovative Middle School in Korea, this study employs sociocultural theory to examine how structures afford and limit student participation in an innovative school designed to promote student-centered learning. Data includes teacher and student interviews, student responses to a questionnaire, classroom observations, and analysis of video recordings of ten lessons in two in two 8th grade science classes. Using structure|agency dialectic theory, we identify and describe some structures that afford and limit teacher and student agency at the micro (science classrooms), meso (school), and macro (Korean society) levels to raise some questions about current reform measures, such as innovation schools, that seek to position classroom teachers as agents for change in science education reform in Korea. Findings suggest that while teachers and school administrators play an essential role in structuring learning opportunities at the meso and micro levels, they have limited agency to address structural constraints originating at the macro-level, which can negatively impact teaching and learning in the science classroom. We offer implications for policy and practice and argue the need for more qualitative research, informed by sociocultural theory, to inform science education reform efforts in Korea.

• Child Health Nursing Research
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• 제23권4호
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• pp.459-469
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• 2017

Purpose: Nurses experience burnout related to various factors. For this descriptive research job stress, compassion satisfaction, and compassion fatigue were examined as to their relationship to burnout in nurses from children's hospital. Methods: The participants were 305 nurses working in children's hospital. Self-report questionnaires were used to measure job stress, compassion satisfaction, compassion fatigue and burnout. Results: Nurses in children's hospital experienced a greater than moderate degree of job stress, compassion satisfaction, compassion fatigue and burnout, whereas differences existed according to general characteristics. Job stress, compassion fatigue and burnout showed a significant positive correlation and results of compassion fatigue and burnout were similar. Also, job stress, compassion satisfaction and compassion fatigue were associated with burnout in nurses working in children's hospital. Conclusion: Findings indicate that as longer work experience is accompanied by higher job stress and burnout, it is necessary to develop intervention programs to reduce burnout among career nurses exposed to greater job stress in children's hospital.

• 대한산업공학회지
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• 제43권1호
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• pp.49-61
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• 2017

This paper proposes an R&D project selection methodology for green technology centered on developing country-oriented technology commercialization. Eight selection criteria are derived from the R&BD logic model : technology needs of developing countries, effectiveness of green technology, technological potentials, domestic technological capability, commercialization feasibility, economic benefits, business feasibility, and spillover effects of developing countries. 21 qualitative and quantitative indicators are then defined for each criterion. The analytic hierarchy process is conducted to produce relative importance of evaluation indicators and to set final priority scores of R&D project candidates. The working of the proposed methodology is provided with the help of a case study example of Green Technology Center. The proposed methodology is expected to be effectively utilized for policy practices of R&D project selection in the field of green technology.

• 한국측량학회지
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• 제34권4호
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• pp.373-382
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• 2016

In this study, an EKF (Extended Kalman Filter) based database reference navigation using both gravity gradient and terrain data was performed to complement the weakness of using only one type of geophysical DB (Database). Furthermore, a new algorithm which combines the EKF and profile matching was developed to improve the stability and accuracy of the positioning. On the basis of simulations, it was found that the overall navigation performance was improved by the combination of geophysical DBs except the two trajectories in which the divergence of TRN (Terrain Referenced Navigation) occurred. To solve the divergence problem, the profile matching algorithm using the terrain data is combined with the EKF. The results show that all trajectories generate the stable performance with positioning error ranges between 14m to 23m although not all trajectories positioning accuracy is improved. The average positioning error from the combined algorithm for all nine trajectories is about 18 m. For further study, a development of a switching geophysical DB or algorithm between the EKF and the profile matching to improve the navigation performance is suggested.

• 한국측량학회지
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• 제32권3호
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• pp.271-279
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• 2014

As an alternative way to overcome the weakness of the global navigation satellite system (GNSS) in hostile situation, a gravity gradient referenced navigation (GGRN) has been developed. This paper analyzed the performance of GGRN with respect to the initial errors, DB resolution as well as update rates. On the basis of simulations, it was found that the performance of GGRN is getting worse when initial errors exist but the navigation results are rapidly converged. Also, GGRN generates better results when DB resolution is higher and update rates are shorter than 20 seconds. However, it is difficult to deduce the optimal parameters for the navigation because some trajectories show better performance in case low-resolution DB is applied or long update rate is supposed. Therefore, further analysis to derive specific update conditions to improve the performance has been performed. Those update conditions would not be generalized for all cases although maximum improvement rate is over 200% in certain case. In the future, some more developments and tests on the combination of various geophysical data and/or algorithms are necessary to construct more stable and reliable navigation system.

• 한국식생활문화학회지
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• 제30권5호
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• pp.545-551
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• 2015

This study was carried out in order to investigate Korean food acculturation by married immigrant women and how it affects their children's eating habits. Using an in-depth interview method, 26 domestically residing married immigrant Chinese, Vietnamese, and Indonesian women in Korea were surveyed to investigate adaption to Korean food at the time of their immigration, their current dietary life, their preferred Korean food, major factors in managing their children's eating habits, etc. The results reveal that depending on the married immigrant women's country of birth, which plays an important role in a family's dietary life and health, acculturation phenomena occurred in which the specific eating habits of each country were grafted into Korean food. Furthermore, due to their school-age children's display of acceptance of both their homeland's and Korea's food culture, we believe that this can become a pivot point for non-governmental diplomacy where Korean food can be understood along with the mothers' countries.

• 한국전문물리치료학회지
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• 제25권3호
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• pp.27-38
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• 2018

Background: At present time, smartphones have become very popular and powerful devices, and smartphone applications with the good validity have been designed to assess human balance ability. Objects: The purpose of this study is to evaluate the feasibility of smartphone acceleration in the assessment of postural control ability for six different conditions. Methods: Twenty healthy college-aged individuals volunteered. Static balance ability was measured twice with one-day interval using smartphone application and 3D motion capture system under the six different conditions. Results: Dominant frequencies for each test condition did not show significant differences except for two conditions. The intra-rater correlation coefficient between the first and second tests showed high correlations in six conditions(r>.70, p<.05). Smartphone acceleration and the acceleration calculated from the 3D marker position data showed high correlation coefficient(r>.80, p<.001). Conclusion: Acceleration recorded from a smartphone could be useful assessment variables for balance test in the clinical field.

• 한국통신학회논문지
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• 제37A권9호
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• pp.746-752
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• 2012

SVC 계층형 비디오는 기본 계층과 확장 계층으로 구성되어 있으며 기본 계층의 정상적인 복호 없이는 확장계층의 복호가 불가능하다는 특징을 가지고 있다. 따라서, SVC 비디오 전송에서 수신 비디오의 품질 향상을 위해서는 기본 계층의 성공적인 전송이 중요한 요소로서 작용한다. 본 논문에서는 다중 릴레이를 통해서 전송되는 시스템에서, 비디오의 품질 향상을 위해 계층형 비디오의 중요도에 따라서 복호 성공 확률을 향상시키기 위한 네트워크 코딩 방법을 제안한다. 제안하는 비디오 데이터 중요도 인지 네트워크 코딩 방식을 수식적으로 분석 및 실험하여 그 결과를 보이고, 또한 릴레이의 수에 따른 비디오 품질의 성능 변화를 보였다.