• Journal of Broadcast Engineering
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• v.25 no.4
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• pp.497-506
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• 2020

A chameleonic surface proposed in this study was a pin-art and 3D display device for generating arbitrary shapes. A smooth and continuous surface was formed using slim telescopic actuators and high-elasticity composite material. Realistic 3D shapes were continuously generated by projecting dynamic mapping images on the surface. A slim telescopic actuator was designed to show long strokes and minimize area for staking. A 3D shape was formed by thrusting and extruding the high-elasticity material using multiple telescopic actuators. This structure was advantageous for generating arbitrary continuous surface, projecting dynamic images and lightening weight. Because of real-time synchronization, a distributed controller based on EtherCAT was applied to operate hundreds of telescopic actuators smoothly. Integrated operating software consecutively generated realistic scenes by coordinating extruded shapes and projecting 3D image from multiple projectors. An opera content was optimized for the chameleon surface and showed to an audience in an actual concert.

• Journal of Internet Computing and Services
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• v.10 no.3
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• pp.131-140
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• 2009

Recently, the information visualization research community has given significant attention to graph visualization, especially visualization of social networks. However, visualization of information flows in a very large social network has not been studied in depth. However, information flows are tightly related to the structure of social networks and it shows dynamic behavior of interactions between members of social networks. Thus, we can get much useful information about social networks from information flows. In this paper, we present our research result that enables users to navigate a very large social network in Google Maps' method and to take a look at information flows on the network. To this end, we devise three techniques; (i) mapping a very large social network to a 2-dimensional graph layout, (ii) exploring the graph to all directions with zooming it in/out, and (iii) building an efficient query processing framework. With these methods, we can visualize very large social networks and information flows in a limited display area with a limited computing resources.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.8
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• pp.1661-1669
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• 2004

A rapid development of Internet is changing users' desire from existing static contents to dynamic and diverse ones. Thus the SVG provides more affluent and sophisticated graphic expressions than an existing method based on bitmap, it can faithfully display vector graphics without scarifying any functions or the problem of device compatibility. In addition, it allows indexing, searching, storing, and sharing by the description of the logical structure of graphics. Since there are, however, very few people who know the complex SVG syntax and make use it, an editing system, which enables users to utilize the SVG graphics easily, has been in need. Therefore, in this thesis, we do research on basic technology on the SVG, design and make an editing system for SVG documents. The system, therefore, provides uses with a user-friendly editing interface and enables them to write graphic objects easily, and generates complex SVG documents automatically.

• Journal of Korea Multimedia Society
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• v.9 no.4
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• pp.377-387
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• 2006

Digital documents takes place of paper (off-line) documents, because of the advantages of digital (on-line) documents: supply of information using dynamic contents and good to communize. However, users prefer paper documents to digital documents with the advantages of paper documents: inexpensive, handy to carry, and good to read. Therefore, for providing advantages of digital documents to users who prefer paper documents, many laboratories study about methods which augment digital documents to paper documents. In this paper, we propose the Hybrid Documents Authoring Tool (HDAT), which can insert, delete, and modify on-line information to the off-line. The proposed system is a unified authoring tool for reading and writing of on-line information. And we provide the most natural environment to users using computer vision technology without additional devices such as markers or patterns to retrieve documents. As shown by experimental results, we make sure that our proposed system has high usability and good efficiency on various environments through we measure the low-level of system requirement.

• Journal of Korean Society on Water Environment
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• v.24 no.3
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• pp.365-377
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• 2008

Large artificial dam reservoirs and associated downstream ecosystems are under increased pressure from long-term negative impacts of turbid flood runoff. Despite various emerging issues of reservoir turbidity flow, turbidity modeling studies have been rare due to lack of experimental data that can support scientific interpretation. Modeling suspended sediment (SS) dynamics, and therefore turbidity ($C_T$), requires provision of constitutive relationships ($SS-C_T$) and accounting for deposition of different SS size fractions/types distribution in order to display this complicated dynamic behavior. This study explored the performance of a coupled two-dimensional (2D) hydrodynamic and particle dynamics model that simulates the fate and transport of a turbid density flow in a negatively buoyant density flow regime. Multiple groups of suspended sediment (SS), classified by the particle size and their site-specific $SS-C_T$ relationships, were used for the conversion between field measurements ($C_T$) and model state variables (SS). The 2D model showed, in overall, good performance in reproducing the reservoir thermal structure, flood propagation dynamics and the magnitude and distribution of turbidity in the stratified reservoir. Some significant errors were noticed in the transitional zone due to the inherent lateral averaging assumption of the 2D hydrodynamic model, and in the lacustrine zone possibly due to long-term decay of particulate organic matters induced during flood runoffs.

• Journal of the Korea Fashion and Costume Design Association
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• v.15 no.4
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• pp.209-221
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• 2013

This study has attempted to investigate the effect of cubism on fashion and figure out how its formative characteristics have been expressed in contemporary fashion in the 21st century, focusing on the period since 2010. The propose of the study is to broaden research scope in fashion design through analysis and inspection on formative aspects among the cases which have proposed brand - new fashion designs by adapting cubism in fashion. To find out the characteristics of cubism in painting and formative characteristics of contemporary fashion in which the characteristics of cubism are reflected, a literature review has been conducted by referring to domestic and foreign books, previous papers, academic journals and Internet resources on cubism. For an empirical study, in addition, photos of cubism-applied modern fashion have been collected and analyzed through http://www. samsungdesign.net. The following results have been obtained: First, the formative characteristics of cubism were obtained in following categories; character of figure, simultaneity, reiteration and facticity. Second, according to analysis on cases after applying the formative characteristics on contemporary fashion design, the character of figure by the geometric shape of cubism was observed in fashion as well. After dismantling and reconfiguring garments, simultaneity has been expressed in an exaggerated and distorted manner through regular and repetitive overlapping or overlapping of irregular shapes. In terms of facticity, novelty has been delivered with the use of heterogeneous materials, using collage and patchwork techniques. Third, simplicity and functionality in cubism - style garments in the early 20th century have disappeared in contemporary design in the 21st century. Now, a dynamic aspect is only found. Fourth, unlike common paintings, 2D textiles are added to a 3D body in fashion design. In addition, it can be observed from multiple angles depending on the movement so that it can display more diverse shapes. Therefore, it could be the origin of inspiration to many designers.

• Journal of the Korean School Mathematics Society
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• v.18 no.2
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• pp.223-240
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• 2015

This paper deals with how to design and develop white-box based e-learning contents which are equipped with conceptual understanding and step-by-step computational procedures for studying vector calculus for science-engineering majors who might need supplementary mathematics learning. Noting that rewriting rules are often used in school mathematics for students' problem solving, the theoretical aspects of rewriting rules are reviewed for developing supplementary e-learning contents for them. The software design of step-by-step problem solving requires careful arrangement of rewriting rules and pattern matching techniques for white-box procedures using a computer algebra system such as Mathematica. Several modules for step-by-step problem solving as well as producing dynamic display of e-learning contents was coded by Mathematica in order to find the length of a curve in vector calculus after implementing several rules for differentiation and integration. The developed contents are equipped with diagnostic modules and immediate feedback for supplementary learning in terms of a tutorial. At the end, this paper indicates the strengths and features of the developed contents for college students who need to increase math learning capabilities, and suggests future research directions.

• Journal of the Korean School Mathematics Society
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• v.19 no.4
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• pp.459-478
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• 2016

With the proven benefits of and increased interest in using technology in education, the role of teachers has become more important in integrating technology into mathematics classroom. Thus, it is important to improve preservice teachers' technological, pedagogical, and content knowledge (TPACK), which are influenced by their beliefs. This study examines how preservice secondary mathematics teachers' experience and beliefs related to technology use in the mathematics classrooms impact their TPACK. The results of this study show that preservice teachers who have more experience using technology and who hold student-centered beliefs towards technology use display higher levels of technology-related knowledge than preservice teachers who have little experience and who hold teacher-centered beliefs. Understanding the relationships between preservice teachers' TPACK and beliefs provides insights into how teacher education programs can support preservice teachers to develop TPACK and integrate technology into their future mathematics instruction.

• Korean Journal of Cognitive Science
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• v.10 no.3
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• pp.67-75
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• 1999

We investigated whether human could perceive the heading direction from the optic flow made from random dots and real images simulating the motion of the observer and objects. When an object moves across the focus of expansion(FOE) in random dot simulation. the observer perceived the focus of expansion biased toward the motion direction of the object. supporting the hypothesis that the direction repulsion is produced between the expansional and the horizontal planar motion components. With real image display observers tended to perceive one's heading direction biased toward the c center of the scene regardless of the direction and position of moving 0bcts. And it was observed that the deeper the depth of the background was the larger the judgment error was. These results suggest it is more likely that human depends on different cues than the optic flow when they perceive or judge one's heading direction in the real environment.

• The Journal of the Korea Contents Association
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• v.7 no.6
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• pp.69-78
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• 2007

In recent years, embedded mobile systems have been expanding their application domains from embedded portable devices which only execute a specialized application such as MP3 player or digital camcoder to digital convergence devices which execute more complicated applications converged various functionalities such as video and audio play, digital dictionary, DMB, games, phone, etc. As it requires the increasing hardware performance such as more faster CPU and more larger RAM, display, disk size, it has brought about a corresponding increase in power consumption. However, coupled with relatively small gains in battery capacity over recent years, the importance of software architecture including intelligent power management has become paramount. In this paper, we have ported UbiFOSTM with energy saving techniques on the ARM9-based MBA2440 platform. For energy savings, we adapted the dynamic power management and the device power management schemes based on monitoring workload. Experimental results with some well-known applications show that proposed low power technique could save energy up to 24 %.