• Journal of the Korean School Mathematics Society
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• v.13 no.4
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• pp.655-678
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• 2010

In the elementary mathematics, geometric education emphasize spatial sense and understandings of figures through development of intuitions in space. Especially space visualization is one of the factors which try conclusion with geometric problem solving. But studies about space visualization are limited to middle school geometric education, studies in elementary level haven't been done until now. Namely, discussions about elementary students' space visualization process and methods in plane or space figures is deficient in relation to geometric problem solving. This paper examines these aspects, especially in relation to plane and space problem solving in elementary levels. First, we investigate visualization methods for plane problem solving and space problem solving respectively, and analyse in diagram form how progress understanding of figures and visualization process. Next, we derive constituent factor on visualization process, and make a check errors which represented by difficulties in visualization process. Through these analysis, this paper aims at deriving an influence of visualization on geometric problem solving in the elementary mathematics.

• Journal of the Korean Society of Visualization
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• v.18 no.3
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• pp.84-89
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• 2020

Cancer cells secrete angiogenic factors, and nearby vasculatures make new blood vessels essential for cancer development and metastasis in response to these soluble factors. Many efforts have been made to elucidate cancer-endothelial cell interactions in vitro. However, not much is known due to the lack of a suitable co-culture platform. Here, we introduce a 3D printing-based microfluidic system that mimics the in vivo-like cancer-endothelial cell interactions. The tumoroids and endothelial cells are co-cultured, physically separated by porous fibrin gel, allowing communication between two cell types through soluble factors. Using this microfluidic system, we were able to visualize new vessel formation induced by tumoroids of different origins, including liver, breast, and ovary. We confirmed that the ovarian tumoroids most induced angiogenesis while the other two cancer types suppressed it. Utilization of the proposed co-culture platform will help the researchers unveil the underlying mechanisms of the dynamic interplay between tumor and angiogenesis.

• Journal of ILASS-Korea
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• v.4 no.4
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• pp.17-23
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• 1999

Recently, many researchers have been studied a D.I. diesel engine because of the exhaust gas restriction and fuel consumption performance. It is well known that the fuel injection characteristics are the key factors on the diesel combustion and exhaust emission. In this study, the fuel injection characteristics of 5-hole injector and the combustion characteristics are investigated with the amount of fuel by means of the visualization method and visualization D.I. diesel engine system. As the results of the experiments, the spray pattern of the fuel injection and the diffusion flame of a D.I. diesel engine are clarified. In addition, combustion phenomena with operation conditions such as engine speed and engine load are made clear.

• Journal of Information Management
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• v.42 no.2
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• pp.85-102
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• 2011

Conventionally, scientific data visualization is thought of as one of activities performed by scientists during the scientific data analysis. However, recently, there exits a set of research papers which count scientific data visualization as a independent research area. They show the research subjects for studying the scientific data visualization technology and methods. In case, a scientist or group of scientists can not solve their own visualization problem due to the unskillfulness and inexperience on using visualization tool. Therefore, it needs to help them by the systematic way for solving the problem. In this study, we analyze and propose the national level scientific visualization support system for scientists. In particular, we first analyze the existing papers and find out the critical success factors. Then, by integrating the findings of the analysis, we propose the research areas which need to be focused, and the strategic direction and specific research topics for scientific data visualization support system in national level.

• The Journal of Industrial Distribution & Business
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• v.11 no.7
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• pp.41-49
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• 2020

Purpose: The purpose of this study is to recognize the role and necessity of public data visualization through prior research, investigation, and data verification processes. In addition, this study intends to check what factors should be considered in order to visualize data on the mobile web. Through this process, by identifying the cognitive load affecting information visualization by type, as a result, I would like to propose an effective information visualization method to effectively deliver public data related to government policies. Research design, data and methodology: In this study, we analyzed the case of information visualization according to infographics, which has been widely used in the public field among various visualization methods. For this study, a questionnaire survey was conducted for young people in their 20s and 30s with the highest mobile usage rate. Results: Based on the results, IPA (Importance Performance Analysis) was performed to conduct cognitive load test tools for information visualization of public data and confirmed the implications for each type of infographics. Conclusions: As a result of research, in order to efficiently deliver public data on the mobile web, first, it is necessary to construct a visual screen that can be easily identified through clear data. Appropriate graphic elements can be used according to the type to make it easier for users to acquire and understand information. Second, it is necessary to provide useful content in visualizing information. Third, in order to efficiently transmit information and increase understanding of data, it is necessary to visualize information that can induce interest in data and form metaphors. Fourth, it is necessary to visualize information to reduce cognitive load in terms of physical and mental aspects in order to accommodate users' comfortable information. Fifth, in order to effectively deliver public data, it is necessary to compose contents and information that are easy for users to understand. This study examines effective information visualization methods to increase the communication effect of public data in response to changes in the data-based intelligent information society and suggests implications for each type considering cognitive loads to help future public institutions to communicate and accept information.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.30 no.4
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• pp.693-704
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• 2020

As a company's network structure is getting bigger and the number of security system is increasing, it is not easy to quickly detect abnormal traffic from huge amounts of security system events. In this paper, We propose traffic visualization analysis system(FDANT-PCSV) that can detect and analyze security events of information security systems such as firewalls in real time. FDANT-PCSV consists of Parallel Coordinates visualization using five factors(source IP, destination IP, destination port, packet length, processing status) and Sankey visualization using four factors(source IP, destination IP, number of events, data size) among security events. In addition, the use of big data-based SIEM enables real-time detection of network attacks and network failure traffic from the internet and intranet. FDANT-PCSV enables cyber security officers and network administrators to quickly and easily detect network abnormal traffic and respond quickly to network threats.

• Journal of the Korea Society of Computer and Information
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• v.16 no.11
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• pp.137-143
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• 2011

In this paper, we implement the ski jump visualization tool using the OpenGL graphics library. Among the evaluation elements of jump, the distance of jump is most important. Also, the distance of jump depends on Lift-to-Drag Ratio. In the previous studies, the visualization too according to the consequential changing of variety factors is insufficient. This study provides an easy style flying posture visualization tool to the user who using Lift-to-Drag Ratio. Furthermore, there is to implement an international standard jumping hill by virtue of entered five main data. The results of this study can be applied with reference data for better ski jump.

• Journal of the Korean Society of Visualization
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• v.22 no.1
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• pp.79-84
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• 2024

As microchips' degree of integration is getting higher, its cooling problem becomes important more than ever. One of the promising methods is using fractal microchannel heat sink by mimicking nature's Murray networks. However, most of the related works have been progressed only by numerical analysis. Perhaps such lack of direct experimental studies is due to the technical difficulty of the temperature and heat flux measurement in complex geometric channels. Here, we demonstrate the direct visualization of in situ temperature profile in a fractal microchannel heat sink. By using the temperature-sensitive fluorescent dye and a transparent Polydimethylsiloxane window, we can map temperature profiles in silicon-based fractal heat sinks with various fractal scale factors (a=1.5-3.5). Then, heat transfer rates and pressure drops under a fixed flow rate were estimated to optimize hydrodynamic and thermal characteristics. Through this experiment, we found out that the optimal factor is a=1.75, given that the differences in heat transfer among the devices are marginal when compared to the variances in pumping power. This work is expected to contribute to the development of high-performance, high-efficiency thermal management systems required in various industrial fields.

• Journal of Elementary Mathematics Education in Korea
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• v.16 no.3
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• pp.359-388
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• 2012

The study aims to extract the framework of sub-factors of spatial sense, to develop test instruments based on the framework to investigate the actual spatial sense ability of fourth to sixth graders in elementary school and to analyze the results. According to the framework of sub-factors of spatial sense of the study, spatial sense has two factors of spatial visualization and spatial orientation. Spatial visualization is divided into mental rotation, mental transformation and figure-ground perception while spatial orientation is categorized into direction sense, distance sense, and location sense. Based on the framework, the test instrument for spatial sense ability was developed and the test was conducted to 430 fourth to sixth students in five elementary schools in capital areas. The following conclusions were drawn from the results obtained in the study. Firstly, the higher school year gets, the more spatial sense grows. However, spatial visualization is developed much more than spatial orientation and their order is reversed with higher graders. Secondly, the most insufficient abilities among fourth to sixth elementary school students' spatial sense were mental transformation of spatial visualization and location sense of spatial orientation. Thirdly, the reasons of differences in sub-factors of spatial sense and graders seem to be from effects of students' learning experiences of spatial sense of mathematics curriculum and the complexities of test items.

• Safety and Health at Work
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• v.15 no.2
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• pp.200-207
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• 2024

Background: Workers are often exposed to hazardous heat due to their work environment, leading to various injuries. As a result of climate change, heat-related injuries (HRIs) are becoming more problematic. This study aims to identify critical contributing factors to the severity of occupational HRIs. Methods: This study analyzed historical injury reports from the Occupational Safety and Health Administration (OSHA). Contributing factors to the severity of HRIs were identified using text mining and model-free machine learning methods. The Multinomial Logit Model (MNL) was applied to explore the relationship between impact factors and the severity of HRIs. Results: The results indicated a higher risk of fatal HRIs among middle-aged, older, and male workers, particularly in the construction, service, manufacturing, and agriculture industries. In addition, a higher heat index, collapses, heart attacks, and fall accidents increased the severity of HRIs, while symptoms such as dehydration, dizziness, cramps, faintness, and vomiting reduced the likelihood of fatal HRIs. Conclusions: The severity of HRIs was significantly influenced by factors like workers' age, gender, industry type, heat index , symptoms, and secondary injuries. The findings underscore the need for tailored preventive strategies and training across different worker groups to mitigate HRIs risks.