• The Transactions of The Korean Institute of Electrical Engineers
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• v.62 no.12
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• pp.1730-1736
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• 2013

Slanted and chirp interdigital transducer(IDT) configurations were studied for generating the surface acoustic wave(SAW) with wide bandwidths on a piezoelectric substrate. These devices can be applied to manipulate optical path of light along the waveguide, ultimately used for optical switches and holographic image implementation. Prior to fabrication, the coupling of modes(COM) modeling and simulation were performed to extract optimal design parameters. The optimally designed wideband device showed wide bandwidth of 30MHz, low insertion loss of -25dB, and abrupt side suppression ratio (SSR). Several design conditions were determined during device implementation, such as slanted angle, aperture length, number of fingers, and central frequencies of IDTs. These factors were experimentally analyzed and described in details in this paper.

• Journal of Korea Game Society
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• v.9 no.6
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• pp.171-178
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• 2009

Multiple layer displacement mapping methods are able to represent more complex and general geometries which cannot be presented by single layer displacement mapping methods, and provide a realistic scene to digital contents such as 3D games and movies with relatively low costs. However, as we use more layers for details, data space is wasted more because lower layers have less displacement data than higher layers. In this paper, we suggest a lossless compression and rendering method of a multiple layer displacement map. Since we compress the map without data loss, the proposed method provides the same quality as the rendering result that uses an original multiple layer displacement map.

• International Journal of Costume and Fashion
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• v.8 no.1
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• pp.18-35
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• 2008

As an essential factor of plasticity in fashion, color reflects socio-cultural trends and has possessed different symbolism in its historical development. This study aims to search for an academic approach towards finding out how the concepts and symbolism of the color white were expressed in actual clothing. This will be realized through the investigation of the various meanings this particular color possesses. The secondary purpose of this study is to give shape to the results of above said academic investigation by proposing their integration into actual fashion design. The methodology employed in this study and results are as follows. First, the symbolism of the color white abstracted from the research of literature on this subject was classified into six categories; purity, grace, abstinence, sublimity, decorativeness, and avant-garde. Second, for empirical research, six designs were developed and produced into white dresses. The development of these dress designs was realized by presenting the symbolism of the aforementioned six categories into images, and the formative constructions of these images by applying various design details, expressive techniques, and characteristics of the materials. Through an investigation into the color white, which has been excluded from previous chromatics research as a major color, integration of the symbolism and chromatic image of this color into the actual fashion design process is made possible. The significance of this study is in that it proposes multifarious possibilities in fashion design, and also in extending the horizon of chromatics research in fashion through the realization of the above process.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2012.10a
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• pp.447-449
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• 2012

There are many essential elements in making the realistic 3D games, of which one of the most important is mapping. Mapping can add the details to 3D objects easily, which are impossible or difficult by modeling alone, and can reduce file data capacities to run the game engine. The theory of the mapping is to throw 2D image on 3D object correctly, but they do not match each other at the rate of 1:1 100 percent completely due to the difference of the fundamental property of them. To solve this problem, various kinds of mapping methods are developed and used. This paper will compare and analyze the characteristics, and merits and demerits of these various kinds of mapping methods and will inquire which method is the most efficient one.

• Communications of Mathematical Education
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• v.21 no.4
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• pp.575-596
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• 2007

This study investigates preservice teachers' development of subject-matter knowledge and pedagogical content knowledge in teaching function concept. This development takes place in the pedagogical mathematics courses in which the theory of constructivism and cooperative learning theory are aligned. Pre and post courses test were administered to examine the development and the follow-up interviews were conducted to gain more details. Analysis of the written questionnaire results and interview transcripts reveal that their limited concept image can be extended and developed in depth through pedagogical mathematics courses that apply reformed teaching methods.

• Journal of Astronomy and Space Sciences
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• v.29 no.2
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• pp.199-208
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• 2012

The world's first geostationary ocean color imager (GOCI) is a three-mirror anastigmat optical system 140 mm in diameter. Designed for 500 m ground sampling distance, this paper deals with on-orbit modulation transfer function (MTF)measurement and analysis for GOCI. First, the knife-edge and point source methods were applied to the 8th band (865 nm) image measured April 5th, 2011. The target details used are the coastlines of the Korean peninsula and of Japan, and an island 400 meters in diameter. The resulting MTFs are 0.35 and 0.34 for the Korean East Coastline and Japanese West Coastline edge targets, respectively, and 0.38 for the island target. The daily and seasonal MTF variations at the Nyquist frequency were also checked, and the result is $0.32{\pm}0.04$ on average. From these results, we confirm that the GOCI on-orbit MTF performance satisfies the design requirements of 0.32 for 865 nm wavelength.

• Bulletin of the Korean Space Science Society
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• 2009.10a
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• pp.49.3-49.3
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• 2009

Geostationary Ocean Colour Imager (GOCI) is the first ocean color instrument that will be operating in a geostationary orbit from 2010. GOCI will provide the crucial information of ocean environment around the Korean peninsula in high spatial and temporal resolutions at eight visible bands. We report an on-going development of imaging and radiometric performance prediction model for GOCI with realistic data for reflectance, transmittance, absorption, wave-front error and scattering properties for its optical elements. For performance simulation, Monte Carlo based ray tracing technique was used along the optical path starting from the Sun to the final detector plane for a fixed solar zenith angle. This was then followed by simulation of red-tide evolution detection and their radiance estimation, following the in-orbit operational sequence. The simulation results proves the GOCI flight model is capable of detecting both image and radiance originated from the key ocean phenomena including red tide. The model details and computational process are discussed with implications to other earth observation instruments.

• Journal of the Korean Society of Clothing and Textiles
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• v.27 no.3_4
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• pp.354-363
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• 2003

In this research, an internet-based fabric information system has been developed. Recently, the numbers of textile industries which have their own homepages to advertise their product fabrics fur apparel through the Internet and textile e-Commerce web sites rapidly increase. Unfortunately, traditional fabric information systems based on direct meeting and trust cannot give sufficient information to numerous visitors of the Internet sites including fabric buyers for apparel. They can just view 3-dimensional fabric images and text-based specifications such as fabric density, composition, colors, weight, etc. To solve these problems, the new fabric information system fur apparel has been developed. The web-based fabric information system is composed of the following six modules; $\circled1$ fabric database management system, $\circled2$ a 3-D fabric drape image viewer to illustrate fabric appearances, $\circled3$ a virtual wearing system to apply a fabric to garment designs, $\circled4$ a fabric property viewer to confirm fabric characteristics, $\circled5$ a QC (quality control) document generator to manufacture high qualify garments with a fabric, and$\circled6$actual display mall to view actual fabrics. The fabric information system is simply performed by visitors clicking the buttons hyper-linked with JAVA applets on web browser. The web-based fabric information system enables the web site visitors to understand fabrics shown on the Internet in more details.

• Korean Institute of Interior Design Journal
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• v.25 no.2
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• pp.83-91
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• 2016

This study is a basic research to suggest user-centered healthcare environmental color, which aims to analyze tendency of color consciousness and preference depending on the user characteristics (generation, gender, residential area, and environment). For this purpose, this study constructed an analysis tool through the literature review with regard to environmental color of healthcare facility and influential factors of color preference. Besides, an online survey regarding general usage and satisfaction, health related color consciousness, and color preference tendency of healthcare facility was conducted targeting from 20s to 60s, total 1,500 persons. The results of this study are as follows: (1) The usage and satisfaction of healthcare facilities were higher for older generation and accessible urban area. (2) The respondents were aware that color and health are related, recognizing 'green' as healthy and stress relieving color. Besides, 'natural' and 'clear' was the highest in health related color image. 'Light' which relates to vitality was high as well for older generation. (3) In the color preference tendency survey, hue PB was generally the most highly preferred, in details, younger generation preferred B and R while older generation preferred G. The survey also showed high value and chroma were preferred, while female and younger generation preferred high value of 9.0 and low chroma close to achromatic color, which presented older generation preferred vivid color.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.7 no.6
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• pp.1231-1236
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• 2006

The contrast control of images with narrow dynamic range is a simple method among enhancement methods for low intensity of image. Histogram equalization is the most common method for this purpose, which stretches the dynamic range of intensity Conventional methods would fail to enhance images with extremely dark and bright regions, because of not considering the shape of histogram. In this paper, we propose a novel adaptive histogram equalization based on histogram matching with multiple Gaussian transformation function. As a result, output images with a couple of peaks of histogram could be improved and the details such as edges in dark regions could be appeared better than conventional method subjectively.