• International Journal of Advanced Culture Technology
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• v.12 no.1
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• pp.209-219
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• 2024

We studied the effects of science high school students on the change of epistemological beliefs in chemistry and the academic achievement of chemistry by completing 'advanced chemistry'. For seven months from July 2023 to January 2024, 80 first-year students at G Science High School in Gyeongnam were surveyed and analyzed for epistemological beliefs about chemistry before and after classes in advanced chemistry. Chemistry academic achievement was classified by 'upper' and 'lower' levels based on the end-of-semester grades of 'advanced chemistry' in the second semester of the first year and analyzed with the SPSS 28 program. After completing advanced chemistry, the epistemological belief in chemistry increased in the proportion of favorable responses. After completing advanced chemistry, the proportion of favorable responses increased in detailed factors such as 'effort', 'math link', 'outcome', 'reality link', and 'concepts', while the 'visualization' factor decreased. Although completing 'advanced chemistry' positively changed students' epistemological beliefs about chemistry, visual expression showed little contribution to understanding chemical concepts. Based on the above results, we will have to focus on the design of instructors' teaching-learning, such as learner-centered inquiry experiments, creative visual expressions, etc., for successful chemistry teaching-learning.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.7
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• pp.585-592
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• 2016

Visualization was done by using $CH^*$ chemiluminescence images and PMT measurements in order to understand the origin of fluctuating pressure and chemical luminosity at about 500 Hz frequency even in stable combustion, which was observed in recent experimental tests, and to find the physical correlation leading to Low Frequency Instability(LFI) in terms of phase angle. In stable combustion, chemical reactions are distributed along the shear layer flow showing a negative coupling(about 180 degree in phase angle) with combustion pressure. However, phase difference is shifted to a positive coupling showing less than 90 degree in unstable case. Also a periodic change in the distribution of chemical reactions is observed along with local flame extinction and the appearance of big scale vortex flow. In the transition to LFI, local flame extinction and small vortex flow start to appear in a row. As seen in the bluff body wake in reactive flow, the periodic appearance of vortex flow seems to share the same physical process of BVK(Bernard Von Karman) instability generation. Thus, the appearance of local extinction in 500 Hz fluctuations is gradually amplified to complete extinctions of about 20 Hz, and it leads into LFI.

• Korean Journal of Remote Sensing
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• v.35 no.3
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• pp.483-489
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• 2019

True color images display colors similar to natural colors. This has the advantage that it is possible to monitor rapidly the complex earth atmosphere phenomenon and the change of the surface type. Currently, various organizations are producing true color images. In Korea, it is necessary to produce true color images by replacing generations with next generation weather satellites. Therefore, in this study, visual enhancement for true color image production was performed using Top of Atmosphere (TOA) data of Advanced Himawari Imager (AHI) sensor mounted on Himawari-8 satellite. In order to improve the visualization, we performed two methods of Nonlinear enhancement and Histogram equalization. As a result, Histogram equalization showed a strong bluish image in the region over $70^{\circ}$ Solar Zenith Angle (SZA) compared to the Nonlinear enhancement and nonlinear enhancement technique showed a reddish vegetation area.

• Journal of The Korean Association For Science Education
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• v.31 no.6
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• pp.942-957
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• 2011

The purpose of this research was to examine the concept of elementary school teachers of combustion. The participants were selected from the elementary school teachers who had various career experiences, 6th grade science teaching experiences, and academic backgrounds on science. For the purpose of this study, 12 elementary school teachers took the concept-test formed five questions on combustion and were interviewed. The concept-test was composed with 'The definition of combustion', 'The reason that the candle was blown out when glass was closed.', 'The existence of oxygen and carbon dioxide of before and after combustion in glass', 'Combustion of iron', 'Combustion products'. And the collected data by semi-structured interviews based on responses to the concept-test. During the analysis of the data, additional interviews by phone, e-mail and Internet messenger were conducted if necessary. The answers to each question were classified into three levels: (Scientific-concept(S), Partial-concept(P), Misconcept(M)). The research results showed that all teachers had misconceptions or partial-concept of more than 50 percent of each question. Teachers who had the 6th grade science teaching experience acquired scientific concepts of the combustion more than teachers who did not have the 6th grade science teaching experience. We should develop visualization materials about the change of gases during combustion and use these materials for implementation of the scientific concept.

• Journal of the Korean earth science society
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• v.44 no.1
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• pp.13-35
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• 2023

Ocean currents play the most important role in causing and controlling global climate change. The water depth of the Yellow Sea is very shallow compared to the East Sea, and the circulation and currents of seawater are quite complicated owing to the influence of various wind fields, ocean currents, and river discharge with low-salinity seawater. The Yellow Sea Warm Current (YSWC) is one of the most representative currents of the Yellow Sea in winter and is closely related to the weather of the southwest coast of the Korean Peninsula, so it needs to be treated as important in secondary-school textbooks. Based on the 2015 revised national educational curriculum, secondary-school science and earth science textbooks were analyzed for content related to the YSWC. In addition, a questionnaire survey of secondary-school science teachers was conducted to investigate their perceptions of the temporal variability of ocean currents. Most teachers appeared to have the incorrect knowledge that the YSWC moves north all year round to the west coast of the Korean Peninsula and is strong in the summer like a general warm current. The YSWC does not have strong seasonal variability in current strength, unlike the North Korean Cold Current (NKCC), but does not exist all year round and appears only in winter. These errors in teachers' subject knowledge had a background similar to why they had a misconception that the NKCC was strong in winter. Therefore, errors in textbook contents on the YSWC were analyzed and presented. In addition, to develop students' and teachers' data literacy, class materials on the YSWC that can be used in inquiry activities were developed. A graphical user interface (GUI) program that can visualize the sea surface temperature of the Yellow Sea was introduced, and a program displaying the spatial distribution of water temperature and salinity was developed using World Ocean Atlas (WOA) 2018 oceanic in-situ measurements of water temperature and salinity data and ocean numerical model reanalysis field data. This data visualization materials using oceanic data is expected to improve teachers' misunderstandings and serve as an opportunity to cultivate both students and teachers' ocean and data literacy.

• 한국연소학회:학술대회논문집
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• 2004.11a
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• pp.85-90
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• 2004

We have presented characteristics of a transitional behavior from a premixed flame to a triple flame in a lifted flame according to the change of equivalence ratio. The experimental apparatus consisted of a slot burner and a contraction nozzle for a lifted flame. As concentration difference of the both side of slot burner increases, the shape of flame changed from a premixed flame to a triple flame, and the liftoff height is decreased to the minimum value and then increase again. Around this minimum point, it is confirmed a transition regime from premixed flame to triple flame. Consequently, the experimental results of the liftoff height, flame curvature and luminescence intensity showed that the stabilized laminar lifted flame regime is categorized by regimes of premixed flame, triple flame and critical flame. In the visualization experiment of smoke wire, the flow divergence and redirection reappeared in premixed flame as well as triple flame. Thus we cannot express the flame front of lifted flame has a behavior of triple flame with only flow divergence and redirection. To differentiate triple flame and premixed flame, ${\Phi}$ value of partially premixed fraction is employed. The partially premixed fraction ${\Phi}$ was constant in premixed flame. In critical flame small gradient appears over the whole regime. In triple flame, typical diffusion flame shape is obtained as parabolic distribution type due to diffusion flame trailing.

• Journal of the Korean School Mathematics Society
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• v.20 no.4
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• pp.369-385
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• 2017

This study is to figure out the activity and disposition of gifted students with face plot in exploratory data analysis at middle school mathematics class. This study has begun on the basis of the doing mathematics at multivariate analysis beyond one variable and two variables. Gifted students were developed the good learning habits theirselves. According to this result, Many gifted students have an interesting experience at data analysis with Face Plot. And they felt the useful methods of creative thinking about graphics with doing mathematics at mathematical tasks. I think that teachers need to learn the visualization methods and to make and to develop the STEAM education tasks connected real life. It should be effective enough to change their attitudes toward teaching and learning at exploratory data analysis.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.24 no.1
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• pp.132-142
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• 2000

The objective of this study is to experimentally investigate the noise propagating characteristics, the noise reduction mechanism and the performance of a slotted tube attached at the exit plane of a circular convergent nozzle. The experiment is performed through the systematic change of the jet pressure ratio and the slot length under the condition of two kinds of open area ratios, 25% and 51%. The open area ratio calculated by the tube length equivalent for the slot length is defined as the ratio of the total slot area to the surface area of a slotted tube. The experimental results for the near and far field sound, the visualization of jet structures and the static pressure distributions in the jet passing through a slotted tube are presented and explained in comparison with those for a simple tube. The propagating characteristics of supersonic jet noises from the slotted tube is closely connected with the slot length rather than the open area ratio, and its propagating pattern is similar to the simple tube. It is shown that the slotted tube has a good performance to suppress the shock-associated noise as well as the turbulent mixing noise in the range of a limited jet pressure and slot dimension. The considerable suppression of the shock‘associated noise is mainly due to the pressure relief caused by the high-speed jets passing through the slots on the tube. Both the strength of shock waves and the interval between them in a jet plume are decreased by the pressure relief. Moreover, the pressure relief is divided into the gradual and the sudden relief depending upon the open area ratio of the slotted tube. Consequently, the shock waves in a jet plume are also changed by the type of pressure relief. The gradual pressure relief caused by the slotted tube with the open area ratio 25% generates the weak oblique shock waves. On the contrary, the weak normal shock waves appear due to the sudden pressure relief caused by the slotted tube with the open area ratio 51%.

• The KIPS Transactions:PartB
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• v.17B no.6
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• pp.437-444
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• 2010

In this paper, we propose a method of analysing the relation between the patient's face color and his(her) kidney disease using image processing technology. This method is based on the ocular inspection which is one of the most famous diagnosis methods used in the oriental medical system. The way of processing and analysing the face image, which is for visualization and objectification of the color difference, is included. The objects are selected from the patients who suffer the kidney disease and use the hemodialyzer. Their facial images and clinical data are collected. From these data, we propose a hypothesis that the color of the patient's face is changed according to the patient's kidney state. At the same time, we present two algorithms of extracting the specific part of face which can identify the state of the patient's kidney and tracing the history of the color's change. This proposed method is evaluated through the practical experiments and their analysis.

• The Journal of the Korea Contents Association
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• v.11 no.6
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• pp.197-204
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• 2011

In line with the development of Media, the use of character has been developed in various ways. Specially, it has been emerged the functions of written language of visualization and delivery of emotion in the digitalized environment due to speedy growth of internet and Mobile. The emoticons emerged as a tool for the convenience of communication proved to have taken effective role in the part of communication culture. Particularly, Hangul emoticons which contains the meaning of communication and sharing in tandem with the principle of Hangul invention, provides convenience in combination & use due to its structural and design characteristic for which it plays a significant role of visual element. Hangul emoticon is definitely a part of Hangul culture and in view of globalization of visual language in connection with media development, there is a huge potential being to be used as a international communication tool. In this study, it will be reviewed on the increased utilization of Hangul emoticons and related public issues as being a part of typography media, in view of the generalization of private media as well as change of subjective user.