• Current Optics and Photonics
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• 제8권2호
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• pp.183-191
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• 2024

High-resolution retinal imaging based on adaptive optics (AO) is important for early diagnosis related to retinal diseases. However, in practical applications, closed-loop AO correction takes a relatively long time, and traditional open-loop correction methods have low accuracy in correction, leading to unsatisfactory imaging results. In this paper, a SH-U-net-based open-loop AO wavefront correction method is presented for a retinal AO imaging system. The SH-U-net builds a mathematical model of the entire AO system through data training, and the Root mean square (RMS) of the distorted wavefront is 0.08λ after correction in the simulation. Furthermore, it has been validated in experiments. The method improves the accuracy of wavefront correction and shortens the correction time.

• 한국초등과학교육학회지:초등과학교육
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• 제35권1호
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• pp.89-97
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• 2016

Science contest is one of the important programs of extracurricular school science activities which give various experience for science learning. In order to understand teachers' perceptions on science contests in elementary school, this study investigated teachers' awareness of science contests, perceptions and difficulties in carrying out science contests in each school, their perceptions on the preparing process of statewide science contest, and the preference of the types of preliminary science contests. 196 teachers were responded to survey, and 8 teachers were interviewed. The results showed that elementary teachers were aware of various science contests through their in-school experiences. The main difficulties of teacher on science contests was lack of professionalism on science and science contests. While teachers preferred the preliminary round of contest by contest's host to the preliminaries of science contest in each school. They also worried about the intimidation of science month's festival in schools. Based on the understanding of the teachers' perceptions on science contests, educational implications were discussed.

• 한국초등과학교육학회지:초등과학교육
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• 제29권1호
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• pp.86-92
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• 2010

Although constructivist assessment has been emphasized by many science educators, most elementary school teachers are still not familiar with this. In order to investigate the causes of this problem, we examined the perceptions of pre-service elementary school teachers toward constructivist science assessment and the relationships among the perceptions toward constructivist science assessment, the views on science teaching and learning, science teaching efficacy beliefs, and the perceptions toward constructivist science learning environment. Analyses of the results revealed that the perceptions of pre-service elementary school teachers toward constructivist science assessment were higher than those of the elementary school teachers reported previously. The results of a stepwise multiple regression analysis indicated that the views on constructivist science teaching and learning and personal science teaching efficacy beliefs were the significant predictors of the perceptions toward constructivist science assessment.

• 한국운동역학회지
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• 제32권3호
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• pp.94-102
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• 2022

Objective: The purpose of this study was to investigate the effect of acute transcranial direct current stimulation (tDCS) on the isokinetic muscular endurance of the lower extremity for young adults. Method: Thirteen young adults performed isokinetic fatigue tasks for two experimental conditions including real tDCS and sham stimulation protocols. Before and after the task, the tensiomyography was used for evaluating muscle contraction characteristics of vastus medialis and semitendinosus. Paired t-test was performed to compare the fatigue index, changes in maximum radial displacement (∆Dm), delay time (∆Tc), and velocity of contraction (∆Vc) between tDCS conditions. Results: We found no significant differences in the fatigue index between real and sham conditions. In addition, the analyses identified no significant different values of ∆Dm, ∆Tc, and ∆Vc in the vastus medialis and semitendinosus between real and sham conditions. Conclusion: These findings suggest that the tDCS protocols may have no acute effect on lower limb muscle endurance for young adults. Future studies should consider the long-term effects of repetitive tDCS sessions, various stimulation positions, exercise tasks, and participant characteristics to more clearly understand the effect of tDCS on muscle endurance of lower extremities.

• 한국생명과학회:학술대회논문집
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• 한국생명과학회 2006년도 제47회 학술심포지움 및 추계국제학술대회
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• pp.118.1-118.1
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• 2006

• 한국과학교육학회지
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• 제24권1호
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• pp.157-170
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• 2004

Students experience science not only through school science lessons but also through various other channels. Science-related facilities, including science museums and centers, are important channels for informal science education. Korea has a number of governmental and private facilities in which young people can experience various aspects of scientific activities, and many of them also provide the programs supporting out-of-school science activities. However, there has been no systematic survey study on those facilities providing out-of-school activities, thus they have not been used effectively as well as their social utility is not fully realized. To this end, in 2002 researchers of this study carried out surveys (1) of the facilities supporting out-of-school science activities and (2) of science programs provided by these facilities. The surveys show that there are approximately 180 facilities supporting science activities in Korea. More than 40% of them are located in Seoul and Gyeonggi areas. Among them, the proportion of special theme science museums was the greatest (37.9%). The facilities supporting out-of-school science activities usually do not target the specific age groups but are intended for all people. The proportion of governmental facilities exceeds that of private ones. 41.8% of the facilities examined in this study run their own science activity programs. Among the 10 categories of the programs, 'science class' type programs were the most common. There were more programs for elementary and middle school students than preschoolers, high school students and adults. The contents of the programs were more related to astronomy and meteorology, the observation of living things and field trips. Despite their high practical potential, the special theme science museums were found to be lacking in relevant programs, which could fulfill their values for informal science education.

• 한국축산식품학회지
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• 제44권1호
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• pp.165-177
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• 2024

Volatile compounds (VOCs) are an important factor affecting meat quality. However, the characteristic VOCs in different parts of donkey meat remain unknown. Accordingly, this study represents a preliminary investigation of VOCs to differentiate between different cuts of donkey meat by using headspace-gas chromatography-ion mobility spectrometry (HS-GC-IMS) combined with chemometrics analysis. The results showed that the 31 VOCs identified in donkey meat, ketones, alcohols, aldehydes, and esters were the predominant categories. A total of 10 VOCs with relative odor activity values ≥1 were found to be characteristic of donkey meat, including pentanone, hexanal, nonanal, octanal, and 3-methylbutanal. The VOC profiles in different parts of donkey meat were well differentiated using three- and two-dimensional fingerprint maps. Nine differential VOCs that represent potential markers to discriminate different parts of donkey meat were identified by chemometrics analysis. These include 2-butanone, 2-pentanone, and 2-heptanone. Thus, the VOC profiles in donkey meat and specific VOCs in different parts of donkey meat were revealed by HS-GC-IMS combined with chemometrics, whcih provided a basis and method of investigating the characteristic VOCs and quality control of donkey meat.

• 한국지구과학회지
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• 제38권5호
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• pp.367-377
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• 2017

The purpose of this research is to investigate characteristics of science content knowledge and pedagogical content knowledge shown in the primary school science classes. Through analysis of classroom teaching, explore the features and differences between primary and secondary school science PCK. Using open-ended interviews with the teachers and group discussions on a regular basis to analyze and compare classes of five primary school teachers, the relationship between CK and PCK. Regardless of the school level the teacher's PCK and professionalism is required with varying focus and emphasis. The features of the primary school teacher's PCK are as follows: Firstly, elementary teach secondary teach content, teachers value pedagogical knowledge (PK) content knowledge (CK). The primary school PCK requires more of understanding of students and teaching methods that to subject areas. PCK be without content knowledge, and the teacher's PCK is subject-specific In addition to the characteristics of PCK in the primary school science teaching, ways to set up professional exchange or collaboration between primary and secondary teachers, and to provide supplementary in-service training focused on content knowledge for primary school teachers.

• 한국초등과학교육학회지:초등과학교육
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• 제29권3호
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• pp.243-251
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• 2010

The purpose of this study is to investigate the relationships between elementary school teachers' points of view about the organization of the science curriculum and their views on the nature of science (NOS). We surveyed 132 elementary school teachers' view points about these two kinds of views, analyzed the data by their variables, and compared the two viewpoints with their personal details. The elementary school teachers thought the science curriculum should be emphasized through the process more than contents. They thought the contents of the science curriculum should be integrated rather than separated. As teachers' career progressed, they focused on the contents more than the process. On the other hands, because elementary school teachers showed the NOS views as relativism, deductivism, decontextualism, content, and instrumentalism, when we plotted sub-viewpoints of NOS in process-content dimension, we thought it would be similar distributions with point of views on the organization of science curriculum. However, there was no meaningful relation. This showed that teachers' views on the organization of the curriculum and the NOS are totally different. These findings suggest further research is needed to find how factors influence elementary school teachers' views on the organization of the science curriculum and what inclinations can occur in science classes with their different views.

• 한국작물학회:학술대회논문집
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• 한국작물학회 2003년도 추계 학술발표회 요지
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• pp.256-257
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• 2003