• Journal of the Korean Magnetics Society
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• v.13 no.3
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• pp.127-132
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• 2003

Natural convection of a magnetic fluid is different from that of Newtonian fluids because magnetic-body force exists in addition to gravity and buoyancy. In this paper, natural convection of a magnetic fluids (W-40) in a cubic cavity was examined by experimental method. One side wall was kept at a constant temperature (25 $^{\circ}C$), and the opposite side wall was also held at a constant but lower temperature (20 $^{\circ}C$). The magnetic fields of various magnitude were applied up and down by permanent magnets. We measured temperatures at 5 points which are the most suitable places in cavity by the analysis record. The thermo-sensitive liquid crystal film (R20C5A) was utilized in order to visualize wall-temperature distributions. Several kinds of experiments were carried out in order to clarify the influence of direction and intensity of magnetic fields on the natural convection. It was found that the natural convection of a magnetic fluids could be controlled by the direction and intensity of the magnetic fields.

• The Journal of Industrial Distribution & Business
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• v.11 no.5
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• pp.45-52
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• 2020

Purpose: In the 4th industrial revolution, services that incorporate various smart technologies in the tourism sector have begun to gain popularity. Accordingly, academic discussions on smart tourism have also started to become active in various fields. Despite recent research, the definition of smart tourism is still ambiguous, and it is not easy to differentiate its scope or characteristics from traditional tourism concepts. Thus, this study aims to analyze the perception of smart tourism exposed online to identify the current point of smart tourism in Korea and present the research direction for conceptualizing smart tourism suitable for the domestic situation. Research design, data, and methodology: This study analyzes the perception of smart tourism exposed online based on 20,198 news data from portal sites over the past six years. Data on words used with smart tourism were collected from the leading portal sites Naver, Daum, and Google. Text mining techniques were applied to identify the social awareness status of smart tourism. Network analysis was used to visualize the results between words related to smart tourism, and CONCOR analysis was conducted to derive clusters formed by words having similarity. Results: As a result of keyword analysis, the frequency of words related to the development and construction of smart tourism areas was high. The analysis of the centrality of the connection between words showed that the frequency of keywords was similar, and that the words "smartphones" and "China" had relatively high connection centrality. The results of network analysis and CONCOR indicated that words were formed into eight groups including related technologies, promotion, globalization, service introduction, innovation, regional society, activation, and utilization guide. The overall results of data analysis showed that the development of smart tourism cities was a noticeable issue. Conclusions: This study is meaningful in that it clearly reflects the differences in the perception of smart tourism between online and research trends despite various efforts to develop smart tourism in Korea. In addition, this study highlights the need to understand smart tourism concepts and enhance academic discussions. It is expected that such academic discussions will contribute to improving the competitiveness of smart tourism research in Korea.

• Journal of Korea Multimedia Society
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• v.16 no.5
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• pp.647-656
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• 2013

The desire of humankind that longed for reappearance of visual makes progress within the development of linear history. The directing point at the moment was the 'eye'. Upon completion of setting the aiming point, visual image attempts reflection of main agent beyond reappearance of it and, by extension, aimed to visualize desire which was latent in the instance of main agent. It was able to experience a fantasy in paintings, photos and movies as a stage of desire, of course. Digital, however, suggested a new phasis in creating a fantasy world. This study aimed to research the fantastic nature in digital image that a fantastic image is created as a reflection of both independence and unconsciousness. As a result of research, this study revealed that digital image, as a channel that image and imaginative desire which were saved in id, is created as a perfect stage on the basis of verisimilitude, granting an experience toward realization of desire to a main agent raising id which was repressed by the ego and superego to the surface.

• Parasites, Hosts and Diseases
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• v.31 no.2
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• pp.83-90
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• 1993

We performed bromodeoxyuridine (BrdU) staining to observe the proliferation pattern of epithelial cells on the biliaJy mucosa in Clonorchis sinensis infection. Albino rats were infected with 100 metacercariae each and their livers were processed for histopathological observation after BrdU injection. Five to six sites in the liver of a rat were selected for paraffin section, and stained immunohistochemically to visualize BrdU incorporating cells. The flukes were mainly in the common bile duct and right or left hepatic bile ducts. The proportion of stained epithelial cells in the infected bile ducts where the worms were found on the section was 2.9-10.2% at 1 week after infection. 7.3-12.8% at 2 weeks, 7.3-13.4% at 5 weeks, and 8.4-14.8% at 15 weeks while in the non-infected ducts o to 2.7% cells were stained. The stained cells were mainly at the base of the mucosal layer. It is suggested that mucosal epithelial cells of the bile ducts infected with C. sinensis become hyperplastic mainly by direct and local stimulation of the worms.

• The Korean Journal of Applied Statistics
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• v.33 no.5
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• pp.591-601
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• 2020

The self-organizing map (SOM) is a unsupervised learning method projecting high-dimensional data into low-dimensional nodes. It can visualize data in 2 or 3 dimensional space using the nodes and it is available to explore characteristics of data through the nodes. To understand the structure of data, cluster analysis is often used for nodes obtained from SOM. In cluster analysis, the optimal number of clusters is one of important issues. To help to determine it, various cluster validity indexes have been developed and they can be applied to clustering outcomes for nodes from SOM. However, while SOM has an advantage in that it reflects the topological properties of original data in the low-dimensional space, these indexes do not consider it. Thus, we propose a new cluster validity index for SOM based on connectivity between nodes which considers topological properties of data. The performance of the proposed index is evaluated through simulations and it is compared with various existing cluster validity indexes.

• Journal of Internet Computing and Services
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• v.15 no.5
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• pp.33-41
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• 2014

The purpose of this study is to provide statistical analysis based suggestions on effective methods to take advantage of social network service (SNS) for educational purposes based on investigations of undergraduate students with high utilization of SNS. To achieve this, we conducted an open questionnaire survey and qualitatively analyzed the data using NVivo 10 program. Additionally, to visualize the analysis by education subject of the SNS educational methods, we have divided the data into 3 categories of teacher, student and common area. As a result, our analysis showed that the exchange opinions and discussions, information sharing and learning of contents of questions and answers, surveys, intimacy formation, counseling etc. were of the common area. Furthermore, teacher area included the notice announcement, teaching materials sharing, real-time assessment (quiz), attendance check, assignment grading and feedback, etc. Finally the student area was of project activities (group/individual), prepare and review the shared data, video self learning, peer review and feedback of projects, lecture evaluation, etc.

• Korean Journal of Construction Engineering and Management
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• v.14 no.5
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• pp.74-83
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• 2013

Most current BIM systems are focused on the visual information of work status in the design and construction stages. In a passive BIM system, 3D CAD tool can visualize the interference elements of design drawings, however, it cannot suggest a solution to solve the interference status. And 4D CAD tool in the construction stage can simulate the appearance of each activity by construction schedule, however, it cannot suggest an optimized schedule plan considering specified schedule condition of the project. Recently, many organizations need BIM solutions that can improve the work status beyond the level of simple visual information from BIM system. Active BIM system can provide the solutions to the project manager. This study suggests active BIM functions for the solutions and attempts to develop a 4D CAD engine to validate the usability of the functions.

• Spatial Information Research
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• v.22 no.5
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• pp.53-63
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• 2014

As recent interest in ecological resources increases, an effort in three-dimensional visualization of the ecological resources has increased for the restoration and preservation of the natural environment as well as the evaluation of the landscape. However, in the case of forest resources, information extraction has been active, but the effort in trying to apply that information into an effective visualization has not happened. In other words, the effort for effective visualization is lacking when it comes to the visualization of forest resources, and numerous cases are ether non-realistic or the simulation required for analysis is inappropriate. Therefore, this paper extracts information through the use of airborne LiDAR data, aerial photograph, and forest type maps to create a vegetation layer, and then uses Flora3D forest modeling tools and ArcGlobe to accurately visualize the vegetation layer into the three dimension. An effective application for restoration and preservation of ecological resources as well as analysis on the urban landscape can be considered as a result of intuitively and realistically enabling the user's awareness of forest information within the Geographic Information System.

• The korean journal of orthodontics
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• v.46 no.5
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• pp.269-279
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• 2016

Objective: Rapid maxillary expansion (RME) is used to expand the maxilla and increase arch perimeter; yet, there are few reports on its effects on the sphenoid bone. With cone-beam computed topography (CBCT), it is possible to visualize sphenoid bone changes. The purpose of this study was to investigate sphenoid bone changes observed in conjunction with RME treatments, using CBCT. Methods: Sixty patients (34 women and 26 men, aged 11-17 years) underwent RME as part of their orthodontic treatment. Patients were randomly assigned to one of three groups: a tooth-anchored group, a bone-anchored group, or a control group. Initial CBCT scans were performed preceding the RME treatment ($T_1$) and again directly after the completion of expansion ($T_2$). Statistical analysis included ANOVA, descriptive statistics, and the intraclass correlation coefficient (ICC). Results: The reliability of the landmark location was at least 0.783, and the largest ICC mean measurement error was 2.32 mm. With regard to distances, the largest change was 0.78 mm, which was not statistically significant (p > 0.05). Statistical significance was established in patient groups of the same sex and treatment type for the following distance measurements: right anterior lateral pterygoid plate to the right edge of the hypophyseal fossa ($d_2$), anterior distance between the medial pterygoid plates ($d_4$), and anterior distance between the left medial and lateral plates ($d_8$). Conclusions: In this study, there were no clinically significant changes in the sphenoid bone due to RME treatments regardless of sex or treatment type.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.28 no.6
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• pp.464-471
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• 2002

The purpose of this study was to evaluate the stress patterns within fractured mandibles generated by reduction forceps and to determine the optimal position of the reduction forcep. Twenty-seven mandibular models were fabricated using a photoelastic resin. Each of the three sets of mandible models prepared was osteotomized according to one of three different fracture types(symphysis, parasymphysis and body fractures). After reducing the cut segments, a reduction forcep was placed into different engagement holes to compress the segments. Photoelastic stress analysis was used to visualize the stress patterns within the fractured mandiblular models generated by the reduction forcep. In the case of symphysis or parasymphysis fractures, an optimum distribution of stress over the fracture site was achieved when placing the reduction forcep more than 12.5mm on either side of the fracture line between the midway level bisecting the mandible and 5mm below the level. In the case of body fractures, optimum stress distribution was achieved when the reduction forcep was placed more than 15mm from the fracture line on the midway level. In conclusion, a correct use of reduction forceps helps to provide a precise threedimensional reduction for mandibular fractures.