• Journal of Elementary Mathematics Education in Korea
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• v.14 no.3
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• pp.701-722
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• 2010

Students have to investigate, experiment and inquire using the manipulative materials and real-world thing for studying Geometry. Manipulative materials activities encourage to understand mathematical concept and connection of symbol. Experiment activities using the computer focused the student's intuitive and inquisitive activities because of visualization of an abstract mathematics concept. This study developed a workbook through the use of manipulative materials and computer for operating and experimenting, and suggested a method for inquiry of geometrical properties and proved an effect. Manipulative materials-experiment activities was proven effective to middle level and lower level students in understanding the geometrical properties, and was proven effective to high level and lower level students when it comes to mathematical communication ability. When students operate, at first, they have to know about the feature and information of the materials, and the teacher has to make an elaborate plan and encourages the students to discuss about this.

• Journal of KIISE:Software and Applications
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• v.28 no.12
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• pp.875-884
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• 2001

Although the self organizing map (SOM) is widely utilized in such fields of data visualization and topology preserving mapping, since it should have the topology fixed before trained, it has some shortcomings that it is difficult to apply it to practical problems, and classification capability is quite low despite better clustering performance. To overcome these points this paper proposes the dynamic topology preserving self-organizing map(DTSOM) that dynamically splits the output nodes on the map and trains them, and attempts to improve the classification capability by combining multiple DTSOMs K-Winner method has been applied to combine DTSOMs which produces K outputs with winner node selection method. This produces even better performance than the conventional combining methods such as majority voting weighting, BKS Bayesian, Borda, Condorect and reliability sum. DTSOM remedies the shortcoming of determining the topology in advance, and the classification rate increases significantly by combing multiple maps trained with different features. Experimental results with handwritten digit recognition indicate that the proposed method works out to problems of conventional SOM effectively so to improve the classification rate to 98.1%.

• Journal of the Korea Convergence Society
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• v.12 no.12
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• pp.223-233
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• 2021

MyData industry became possible with the revision of the three data-related bills on August 2020, and from February 2021, each individual can make MyData financial service through the app provided by MyData providers. In this study, in order to understand the user experience trend of MyData-based financial asset management apps in the user-centered financial service era, the usability evaluation of 11 apps from 8 MyData providers was conducted for 300 adults, then average value comparison, radial graph analysis, and heatmap analysis were conducted. In app design preference, asset list type was the most preferred type, followed by asset comparison·list type. As for the expected perception of the future benefits that can be enjoyed through My Data, 'diversification of convenient services' was the highest at 45.3%, and as a negative factor felt by users, personal information-related factors were the highest at 71.4%. The results of this study can be used as basic data for the development and improvement of user interfaces for MyData platforms.

• Journal of KIISE:Databases
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• v.30 no.2
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• pp.109-124
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• 2003

Although most commercial relational DBMSs Provide a graphical query language for the user friendly interfaces of the databases, few research has been done for graphical query languages in object databases. Expressing complex query conditions in a concise and intuitive way has been an important issue in the design of graphical query languages. Since the object data model and object query languages are more complex than those of the relational ones, the graphical object query language should have a concise and intuitive representation method. We propose a graphical object query language called GOQL (Graphical Object Query Language) for object databases. By employing simple graphical notations, advanced features of the object queries such as path expressions including set attributes, quantifiers, and/or methods can be represented in a simple graphical notation. GOQL has an excellent expressive power compared with previous graphical object query languages. We show that path expressions in XSQL(1,2) can be represented by the simple graphical notations in GOQL. We also propose an algorithm that translates a graphical query in GOQL into the textual object query with the same semantics. We finally describe implementation results of GOQL in the Internet environments.

• The KIPS Transactions:PartA
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• v.10A no.2
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• pp.149-156
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• 2003

In the latest medical world, the attempt of reconstructing anatomical human body system using computer graphics technology awakes people's interests. Actually, this trial has been made in dentistry too. There are a lot of practicable technology fields using computer graphics in dentistry For example, 3D visualization and measurement of dental data, detection of implant location, surface reconstruction for restoring artificial teeth in prostheses and relocation of teeth in orthodontics can be applied. In this paper, we propose methods for definitely detecting the geometric features of teeth such as cusp, ridge, fissure and pit, which have been used as most important characteristics in dental applications. The proposed methods are based on the approximate curvatures that are measured on a 3D tooth model made by scanning an impression. We also give examples of the geometric features detected by using the proposed methods. Comparing to other traditional methods visually, the methods are very useful in detecting more accurate geometric features.

• KIPS Transactions on Software and Data Engineering
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• v.8 no.10
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• pp.421-426
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• 2019

In this paper, we propose a method to visualize the geometric features of the contact region between proteins in a protein complex. When proteins or ligands are represented as curved surfaces with irregularities, the property that the two surfaces contact each other without intersections is called shape compatibility. Protein-Protein or Protein-Ligand docking researches have shown that shape complementarity, chemical properties, and entropy play an important role in finding contact regions. Usually, after finding a region with high shape complementarity, we can predict the contact region by using residual polarity and hydrophobicity of amino acids belonging to this region. In the research for predicting the contact region, it is necessary to investigate the geometrical features of the contact region in known protein complexes. For this purpose, it is essential to visualize the geometric features of the molecular surface. In this paper, we propose a method to find the contact region, and visualize the geometric features of it as normal vectors and mean curvatures of the protein complex.

• Smart Media Journal
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• v.11 no.7
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• pp.85-93
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• 2022

Currently, Korea is achieving cultural, economic, and social growth as a member of the international community along with its social growth. In the 2000s, local communities and local governments made multidimensional efforts with historical and cultural interests. And as part of that, historical museums were built or expanded to increase the quantity in anticipation of citizens' satisfaction and attracting visitors. However, the qualitative effect of the exhibition space is not achieved. Therefore, in this study, the analysis according to the complex system theory on the interrelationship between exhibition planning, space, and spectators was carried out based on the case of domestic historical museums, and future exhibition space planning or movement lines according to the mutual relationship between the exhibition space and the spectators were conducted. The purpose of this study is to conduct research on specific visualization and data derivation regarding spatial density and spatial perception information.

• Fashion & Textile Research Journal
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• v.16 no.6
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• pp.961-970
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• 2014

Several retailers such as Target and Kohle's and their vendors have piloting the 3D clothing simulation programs to produce garment samples. However, few studies have verified the virtual fit information and 3d visualization process for pants, and no study compared the commercial 3D virtual programs. This study is designed to analyze similarity of fit and appearance between real pants with 3D virtual pants based on three 3D virtual programs (Optitex, CLO 3D, and i-Designer), three lower body types (slim, normal, and thick waist type), and fit status. We selected a representative model for each lower body type, produced their custom pants according to Lee and Nam's method(2007), and took photos of front, side and back view for visual analysis. Then, we virtually tried each model's custom pants on her parametric avatar developed by manually inputting their body measurements using the three 3D virtual program. Thirty fit experts compared the real fit to virtual fit. This study found that 'Optitex' and 'i-Designer' can visualize more effectively than 'CLO 3D' in many fit locations. Regarding the body types, 3D virtual program can visualize pants fit for 'thick waist body type' more preciously than the other body types. With respect to fit status, it does not affect much on the similarity overall.

• ETRI Journal
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• v.42 no.4
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• pp.608-618
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• 2020

We present a novel GPU-based ray-casting algorithm for volume rendering of unstructured grid data. Our volume rendering system uses a ray-casting method that guarantees accurate rendering results. We also employ the per-pixel intersection list concept in the Bunyk algorithm to guarantee an accurate result for non-convex meshes. For efficient memory access for the lists on the GPU, we represent the intersection lists for all faces as an array with our novel construction algorithm. With the intersection lists, we perform ray-casting on a GPU, and a GPU thread handles each ray. To increase ray-coherency in a thread block and improve memory access efficiency, we extend a prior image-tile-based work distribution method to fit modern GPU architectures. We also show that a prior approach using a per-thread local buffer to reduce redundant computation is not appropriate for modern GPU architectures. Instead, we take an on-demand calculation strategy that achieves better performance even though it allows duplicate computations. We applied our method to three unstructured grid datasets with different characteristics. With a GPU, our method achieved up to 36.5 times higher performance for the ray-casting process and 19.7 times higher performance for the whole volume rendering process compared with the Bunyk algorithm using a CPU core. Also, our approach showed up to 8.2 times higher performance than a GPU-based cell projection method while generating more accurate rendering results. These results demonstrate the efficiency and accuracy of our method.

• Journal of KIISE
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• v.41 no.10
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• pp.838-846
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• 2014

Three-dimensional (3D) object retrieval from user-drawn sketch queries is one of the important research issues in the areas of pattern recognition and computer graphics for simulation, visualization, and Computer Aided Design. The performance of content-based 3D object retrieval system depends on the availability of effective descriptors and similarity measures for this kind of data. In this paper, we present a sketch-based 3D object retrieval system by extracting a hybrid edge descriptor which is robust against rotation and translation. The experimental results which are based on HTML5 and WebGL show that proposed sketch-based 3D object retrieval method is very efficient to search and order the 3D objects according to user's intention.