• Journal of Korea Multimedia Society
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• v.16 no.1
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• pp.11-18
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• 2013

This paper presents a SFF(shape from focus) algorithm using a new focus measure based on higher order statistics for the exact depth estimation. Since conventional SFF-based 3D depth reconstruction algorithms used SML(sum of modified Laplacian) as the focus measure, their performance is strongly depended on the image characteristics. These are efficient only for the rich texture and well focused images. Therefore, this paper adopts a new focus measure using HOS(higher order statistics), in order to extract the focus value for relatively poor texture and focused images. The initial best focus area map is generated by the measure. Thereafter, the area refinement, thinning, and corner detection methods are successively applied for the extraction of the locally best focus points. Finally, a 3D model from the carefully selected points is reconstructed by Delaunay triangulation.

• The Journal of the Korea Contents Association
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• v.8 no.11
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• pp.85-93
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• 2008

For music score recognition, several approaches have been proposed including shape matching, statistical methods, neural network based methods and structural methods. In this paper, we deal with recognition for low resolution images which are captured by the digital camera of a mobile phone. Considerable distortions are included in these low resolution images, so when existing technology is used, many problems appear. First, captured images are not stable in the sense that they contain lots of distortions or non-uniform illumination changes. Therefore, notes or symbols in the music score are damaged and recognition process gets difficult. This paper presents recognition technology to overcome these problems. First, musical note to head, stick, tail part are separated. Then template matching on head part of musical note, and remainder part is applied. Experimental results show nearly 100% recognition rate for music scores with single musical notes.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.22 no.3
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• pp.74-79
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• 2021

This study examined the mixing efficiency of exhaust gas and urea according to the mixer shape in the SCR system. For the experiment, an SCR simulation system was manufactured, and a uniformity detector was attached to the catalyst location to measure the uniformity. The experiment was conducted by setting the exhaust-gas flow rate, temperature, mixer type, and catalyst distance as variables. The experimental results confirmed the swirl angle analysis, urea number distribution, and uniformity. The swirl angle experiment of Models A and B confirmed that the swirl angle of Model A was formed approximately 7 to 8 degrees higher over the entire RPM range. When there was no mixer in the SCR system, the urea and water were concentrated to one side. Mixer Model A showed an even distribution overall, and Model B showed a slightly concentrated tendency at the beginning but then showed a stable distribution of urea. The mixing efficiency of 90%, which was the uniformity target, could be satisfied in Model A and Model B. In particular, Model A showed excellent results that satisfied 90% efficiency at 10 cm of the catalyst position.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.30-30
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• 2009

GTA 용접에서 용입, 용접부의 크기와 형상이 형성되는 아크 물리학적 현상을 이해함에 있어서 에너지 분포특성은 매우 중요한 인자이다. GTA 용접에서 아크 길이의 변화와 사용된 실드 가스 종류에 따라 음극인 텅스텐 전극 팁의 아크 루트 직경에 큰 변화를 주며, 양극인 모재 쪽의 에너지 분포에 영향을 미치며 된다. 기존의 연구자들은 저전류나 중전류 영역의 GTA 용접에서 텅스텐 전극의 선단각과 용입 형태와 의 관계를 plasma 기류 등에 의해 고찰하거나, 최대 아크압력에 미치는 전극형상의 영향에 대하여 연구하였다. 용접부에 작용하는 아크 압력의 분포는 결국 운동 에너지의 분포이다. 기존의 연구자들에 비하여 보다 간편한 실험을 통하여 양극 모재위의 아크 압력에 의한 에너지 분포특성을 규명하는 연구가 필요하다. 본 연구의 목적은 GTA 용접의 용접전류 100A~200A 영역에서 아크 길이 변화와 Ar 가스에 $H_2$ 혼합에 따른 측정된 아크 압력으로부터 기존연구자들의 아크 물리학적 결과들을 활용하여 양극 모재 위에 작용하는 전류밀도 분포를 유도하는 것이다. GTA 용접에서 아크 길이의 변화와 Ar 가스에 $H_2$ 혼합은 아크 압력분포에 큰 영향을 미치며, 이에 따라 에너지 분포특성에 많은 영향을 미친다. 아크 길이가 증가함에 따라 Ar가스와 $H_2$ 혼합가스의 에너지 분포는 감소하였고, Ar가스에 $H_2$ 혼합에 의해 아크 에너지가 증가하여 용입형상에 큰 영향을 미칠 것으로 판단된다. 이에 대한 연구는 향후 GTA 용접 응용분야 확대 적용될 것이며, 아크 물리학 연구에 기초적이고 아주 중요한 과학적인 자료가 될 것으로 판단된다.

• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.2119_2120
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• 2009

전압을 인가하였을 때 전계방향에 의해 가역적으로 색이 변화하는 현상을 전기변색(electrochromism)이라고 한다. 이러한 전기채색현상을 보이는 물질을 전기채색물질(electrochromism materials)이라고 하며, 전기채색 물질에 의한 소자를 전기채색소자(electrochromism device : ECD)라고 한다. 전기채색현상은 투과율(transmittance), 반사율(reflectance)의 가역적이며 가시적인 변화이고, 전기화학적인 산화환원 반응과 관련이 있다. 따라서 본 연구에서는 Titanate nanotube(TNT)를 제조하고 전기변색소자(ECD)에 응용하였다. SEM, XRD, UV-Vis등을 이용하여 재료학적 분석을 시행하였으며, 전기화학적 테스트로 cyclic voltammetry를 측정 하였다. 그 결과 TNT 분말은 직경 약 20~30 nm, 길이 약 500~600 nm 의 입자형상을 나타내었으며, X-선 회절시험결과 $H_2Ti_2O_5{\cdot}H_2O$의 층상구조를 나타내었다. 제조된 막은 FTO glass 위에 PEI/(TNT/TBAOH)$_{n-1}$/PDDA의 순으로 코팅되었다. 전기화학적 테스트를 위하여 2전극 시스템을 제작하였으며, 여러 종류의 액체 전해질을 제작하여 cycle voltammetry를 시행하였다. 그 결과, 각각의 전해질에서 "-"영역의 산화환원전위 피크가 뚜렷하게 나타났으며, 짙은 갈색으로의 채색현상을 나타냈다. 본 연구의 결과로서 TNT 박막을 이용한 ECD은 광조절 유리로서 뿐만 아니라, 여러 전기채색 디바이스에 응용될 것으로 사료된다.

• The Journal of the Acoustical Society of Korea
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• v.19 no.3
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• pp.92-99
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• 2000

In this paper, theoretical acoustic sensitivity was derived to describe acousto-optic transduction property of the mandrel type fiber optic acoustic sensor with respect to external acoustic field. The acoustic sensitivity was analyzed in relation to both material properties and geometrical influence factors of the constitutional parts of the sensor, analytically. Validity of the theoretical results were verified through comparison with the finite element analysis results. The variation trends of the sensitivity of the sensor in relation to the studied parameters showed good agreement for the two analysis methods. According to the results, it is considered more economical to design the basic structure of the sensor with the analytic equations developed in this paper, and then to carry out further detailed analysis with the finite element method for specific points of design interest.

• Archives of design research
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• v.12 no.2
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• pp.147-154
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• 1999

This is a suggestional thesis for fu. ;her study on computer game design. We can understand the computer game design as a new form of communication design.The particular qualities of computer game as communication is: 1. computer game is not a mere recording of past events but a creative reproduction by the player.; 2. its production procedure is a multiple structure of program engineering and multimedia design. Computer game design should be more than just production of visual image or technical results. It could be the design of "fields for training of identity".ity".uot;.

• Journal of Industrial Convergence
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• v.20 no.10
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• pp.33-38
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• 2022

In this paper, a simple method of forming a solution-based carbon nanotube (CNT) for use as a conductive material for electronic devices was studied. The CNT thin film coating was performed on the glass by applying the spin coating method and the argon atmospheric pressure plasma process. In order to observe changes in electrical and physical properties according to the number of coatings, samples formed in the same manner from times 1 to 5 were prepared, and surface shape, reflectance, transmittance, absorbance, and sheet resistance were measured for each sample. As the number of coatings increased, the transmittance decreased, and the reflectance and absorptivity increased in the entire measurement wavelength range. Also, as the wavelength decreases, the transmittance decreases, and the reflectance and absorption increase. In the case of electrical properties, it was confirmed that the conductivity was significantly improved when the second coating was applied. In conclusion, in order to replace CNT with a transparent electrode, it is necessary to consider the number of coatings in consideration of reflectivity and electrical conductivity together, and it can be seen that 2 times is optimal.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.37 no.3
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• pp.531-539
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• 2017

The strut-tie model approach has been recognized as an efficient methodology for the design of all types of concrete members with D-regions, and the approach has been accepted in design codes globally. However, the design of concrete members with the approach requires many iterative numerical structural analyses, numerous graphical calculations, enormous times and efforts, and designer's subjective decisions in terms of the development of appropriate strut-tie model, determination of required areas of struts and ties, and verification of strength conditions of struts and nodal zones. In this study, a computer graphics program, that enables the design of concrete members efficiently and professionally by overcoming the forementioned limitations of the strut-tie model approach, is developed. In the computer graphics program, the numerical programs that are essential in the strut-tie model analysis and design of concrete members including finite element analysis programs for the plane truss and solid problems with all kinds of boundary conditions, a program for automatic determination of effective strengths of struts and nodal zones, and a program for graphical verification of developed strut-tie model's appropriateness by displaying various geometrical shapes of struts and nodal zones, are loaded. Great efficiency and convenience during the application of the strut-tie model approach may be provided by the various graphics environment-based functions of the proposed program.

• Proceedings of the Korean Vacuum Society Conference
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• 2012.02a
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• pp.399-399
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• 2012

II-V 족 화합물 반도체인 황화카드뮴(CdS)은 상온에서 2.42 eV의 밴드갭을 갖는 직접 천이형 물질로서 CdTe 또는 $CuInSe_2$와 같은 박막형 태양전지의 투과층(window layer)으로 널리 사용되고 있다. CdS 박막은 전자빔 증착법(e-beam evaporation), 화학용액증착법(chemical bath deposition), 열분해법(spray pyrolysis), 스퍼터링법(sputtering) 등으로 제작되고 있다. 이 중 스퍼터링법의 경우, 다른 증착법에 비해 조작이 간단하고 넓은 면적에서 균일한 박막을 증착할 수 있을 뿐만 아니라, 박막두께 조절이 용이하다. 따라서 본 실험에서는 RF 마그네트론 스퍼터링법으로 증착된 CdS 박막의 기판온도 및 열처리 온도변화에 따른 구조적 및 광학적 특성을 조사하였다. 기판은 RCA 기법으로 세정된 Corning Eagle 2000 유리 기판을 사용하였다. 박막 공정은 초기 진공 $1{\times}10^{-6}Torr$ 상태에서 20 sccm의 Ar 가스를 주입하고 100 W의 RF 파워, 7 mTorr의 공정 압력에서 기판 온도를 $200^{\circ}C$부터 $500^{\circ}C$까지 변화시키면서 수행하였다. 증착된 CdS 박막은 질소 분위기의 가열로(furnace)를 이용해 $300-500^{\circ}C$ 온도에서 30분간 열처리되었다. 시료들의 표면 형상은 scanning electron microscope를 사용하여 관찰하였으며, UV-vis-NIR spectrophotometer를 사용하여 400-1,000 nm 파장영역에서의 투과율을 측정하였다. 그리고 X-선 회절분석(X-Ray Diffraction)으로 결정구조를 조사하고 결정립 크기를 산출하였다.