• 한국전산유체공학회:학술대회논문집
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• 2010.05a
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• pp.524-529
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• 2010

In the present study, a CFD program is developed for the Fluid-Structure Interaction(FSI) analysis. The non-staggered, non-orthogonal, and unstructured grid system was also used to handle the complicated geometries in the program. In order to validate the capabilities of the developed CFD program, various models are investigated by using unstructured and nonorthogonal meshes. The predicted results are a good agreement with analytic solution, experimental data and commercial software. And also PISO algorithm is applied for transient flow analysis. The cyclic boundary condition and baffle cell are developed in order to improve the effectiveness of the calculation for complex geometry.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.483-487
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• 2011

In the present study, a CFD program based on a finite volume method was developed by using an unstructured polyhedral grid system for the accurate simulation with the complex geometry of computational domain. To simulate the transient flow induced by the moving solid object, the program used a fractional step method and a ALE (Algebric Lagrangian-Eulerian) method. The grid deformation for the moving of solid object were performed with a spring analogy based on the center coordinate of each computational grid. To verify the present program with these methodologies, the numerical results of the flow around the fixed and oscillating circular cylinder were compared with the previous numerical results.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.5
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• pp.648-657
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• 2002

This paper presents a numerical analysis on the solidification characteristics in twin-roll strip casting. Unstructured fixed-grid system was employed to deal with phase change. Melting of pure gallium was analyzed to confirm the validity of present program in both structured and unstructured grid systems. An algorithm for simultaneous calculation of the temperature in the roll and the molten metal pool was developed. The flow field in the pool and heat transfer features between pool and roll were shown. The effect of process parameters was also studied. Since the geometry of the molten metal Pool significantly deforms along the casting direction, unstructured grid system is more efficient. The unstructured grid system gives almost the same accuracy, even though the number of grids is only 60% of the structure done.

• Journal of Korea Multimedia Society
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• v.22 no.3
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• pp.374-385
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• 2019

A Web Crawler is a program, which is commonly used by search engines to find the new brainchild on the internet. The use of crawlers has made the web easier for users. In this paper, we have used unstructured data by structuralization to collect data from the web pages. Our system is able to choose the word near our keyword in more than one document using unstructured way. Neighbor data were collected on the keyword through word2vec. The system goal is filtered at the data acquisition level and for a large taxonomy. The main problem in text taxonomy is how to improve the classification accuracy. In order to improve the accuracy, we propose a new weighting method of TF-IDF. In this paper, we modified TF-algorithm to calculate the accuracy of unstructured data. Finally, our system proposes a competent web pages search crawling algorithm, which is derived from TF-IDF and RL Web search algorithm to enhance the searching efficiency of the relevant information. In this paper, an attempt has been made to research and examine the work nature of crawlers and crawling algorithms in search engines for efficient information retrieval.

• 한국전산유체공학회:학술대회논문집
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• 2007.04a
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• pp.91-94
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• 2007

A GUI based pre/post processor program, which is based on the MFC and OpenGL library in the Windows O/S, hee been developed for NUFLEX Using this program, users are able to generate and modify structured or unstructured grid geometries, set all the parameters for the solver, and observe the results of the simulation in graphic view by vector or scalar plots. The mesh geometry data can be imported from or exported to other programs by supporting functions for reading from and writing to CGNS data format files.

• The Journal of the Convergence on Culture Technology
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• v.6 no.4
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• pp.715-720
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• 2020

In Big data analysis, text data is mostly unstructured and large-capacity, so analysis was difficult because analysis techniques were not established. Therefore, this study was conducted for the possibility of commercialization through verification of usefulness and problems when applying the big data word cloud technique, one of the text data analysis techniques. In this paper, the limitations and problems of this technique are derived through visualization analysis of the "President UN Speech" using the R program word cloud technique. In addition, by proposing an improved model to solve this problem, an efficient method for practical application of the word cloud technique is proposed.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.50 no.6
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• pp.367-376
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• 2022

In this study, a steady and unsteady aerodynamic analysis program using a 3-dimensional subsonic unstructured panel method is developed and verified. Surfaces of bodies are modeled with the source and doublet distributions on triangular or quadrilateral panels. Geometry modeling of complex geometries and multi-body, therefore, can be easily accomplished. The Kelvin theory and the unsteady Kutta condition allow the doublet strength of the wake panels determined for unsteady flows. Various steady and unsteady flows in two and three dimensions are computed and compared with the analytical and the published computational results.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.33 no.3
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• pp.347-370
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• 2022

Most public library websites provide unstructured cultural program data, which cannot be produced and utilized systematically as bibliographic information. It is not sufficiently used in existing library big data research or cases, and there is a risk of disappearing when the website is reorganized or the person in charge is changed. This study developed a data schema that can be used in conjunction with bibliographic data by collecting and analyzing cultural programs and community service data produced in an unstructured manner and proposed to share and utilize public library cultural programs and community service data, and establish a library big data platform that can serve as an information channel between librarians who are cultural program planners. Library program data posted on the library website can be integrated and managed through the platform, securing continuity of work, and systematically managing and preserving the specialized service history of individual libraries.

• International Journal of Contents
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• v.15 no.4
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• pp.113-119
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• 2019

It has been reported that large amounts of information on agri-foods were delivered to consumers through television and social networks, and the information may influence consumers' behavior. The purpose of this paper was first to analyze relations of social network service and broadcasting program on paprika consumption in the aspect of amounts to purchase and identify potential factors that can promote paprika consumption; second, to develop prediction models of paprika consumption by using structured and unstructured big data. By using data 2010-2017, cross-correlation and time-series prediction algorithms (autoregressive exogenous model and vector error correction model), statistically significant correlations between paprika consumption and television programs/shows and blogs mentioning paprika and diet were identified with lagged times. When paprika and diet related data were added for prediction, these data improved the model predictability. This is the first report to predict paprika consumption by using structured and unstructured data.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.18 no.2
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• pp.387-393
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• 2014

In recent years, the spread of computers is increasing, and efficient processing effort for unstructured Big Data is required. In this paper, we are proposed a system to extract the data typed in a word processor quickly by user creating and XML mapping file after converting XML data that has been entered in the office file(HWP, MS-office). In addition, we proposed a system is able to lookup the necessary data from a database by entered form in advance and convert word processor document to office files by the application program. The unstructured big data will be available to be used.