• 대한전기학회:학술대회논문집
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• 대한전기학회 2004년도 추계학술대회 논문집 전력기술부문
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• pp.183-186
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• 2004

본 논문에서는 Lie Group 및 Lie Transformation의 수학적인 근원을 분석하고 이를 비선형 제어기에 제공하였다. 제어기의 구성형태는 Lead-Lag와 LQR 관측기를 결합한 혼합형 비선형 전력계통안정화장치(NPSS)이다. 이 분석에 사용된 제어기는 첫째로 기존의 PSS type인 Lead-Lag 형태의 선형화 제어기이다. 둘째로 제안된 제어기는 Lie group theory를 적용하여 이를 상태변수에 반영한 Lead-Lag와 LQR 관측기를 결합한 것이다. 제안된 혼합형 비선형 전력계통안정화장치(NPSS)의 효과분석은 MATLAB을 이용하였다. 분석모델은 1기 4차 비선형 전력계통의 모델에 적용하였다.

• International journal of advanced smart convergence
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• 제9권4호
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• pp.179-183
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• 2020

The online education platform market is developing rapidly after the coronavirus infection-19 pandemic. As school classes at various levels are converted to non-face-to-face classes, interest in non-face-to-face online education is increasing more than ever. However, the majority of online platforms currently used are limited to the fragmentary functions of simply delivering images, voice and messages, and there are limitations to online hands-on training. Indeed, digital transformation is a traditional business method for increasing coding education and a corporate approach to service operation innovation strategy computing thinking power and platform model. There are many ways to evaluate a computer programmer's ability. Generally, piecemeal evaluation methods are used to evaluate results in time through coding tests. In this study, the purpose of this study is to propose a comprehensive evaluation of not only the results of writing, but also the execution process of the results, etc., and to evaluate the programmer's propensity habits based on the programmer's coding experience to evaluate the programmer's ability and productivity.

• 한국정밀공학회지
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• 제12권6호
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• pp.87-95
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• 1995

In order to predict the case depth and case width in laser transformation hardening, a finite element method was used to analyze the temperature distribution on the material. Laser hardening of the specimens of SM45C and STE11steels was experimented by using the continuous wave CO$_{2}$ laser with the various travel speeds and the defocused Gaussian beam mode. Phosphate coating was adopted on the surface of SM45C to increase the absorption of 10.6 .mu. m laser energy. Experimental data show good agreement with the theoretical predictions. The maximum possible case depth can be predicted for the given laser hardening conditions, such as laser power, and travel speed.

• Kyungpook Mathematical Journal
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• 제64권1호
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• pp.57-68
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• 2024

Let V₃(z, f) and 𝜎⁽¹⁾₃(z, f) be the cubic polynomials representing, respectively, the 3rd de la Vallée Poussin mean and the 3rd Cesàro mean of order 1 of a power series f(z). If 𝒦 denotes the usual class of convex univalent functions in the open unit disk centered at the origin, we show that, in general, V₃(z, f) ⊀ 𝜎⁽¹⁾₃(z,f), for all f ∈ 𝒦. Making use of polylogarithms, we identify a transformation, Λ : 𝒦 → 𝒦, such that V₃(z, Λ(f)) ≺ 𝜎⁽¹⁾₃(z, Λ(f)) for all f ∈ 𝒦. Here '≺' stands for subordination between two analytic functions.

• International journal of advanced smart convergence
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• 제13권1호
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• pp.77-84
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• 2024

This study delves into the subtle sounds emanating from beneath the earth's surface to unveil hidden messages and the movements of life. It transforms these acoustic phenomena into digital data and reimagines them as visual elements. By employing Sismophone microphones and utilizing the FFT function in p5.js, it analyzes the intricate frequency components of subterranean sounds and translates them into various visual elements, including 3D geometric shapes, flowing lines, and moving particles. This project is grounded in the sounds recorded in diverse 'spaces of death,' ranging from the tombs of Joseon Dynasty officials to abandoned areas in modern cities. We leverage the power of sound to transcend space and time, conveying the concealed narratives and messages of forgotten places .Through the visualization of these sounds, this research blurs the boundaries between 'death' and 'life,' 'past' and 'present,' aiming to explore new forms of artistic expression and broaden perceptions through the sensory connection between sound and vision.

• 전자통신동향분석
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• 제39권3호
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• pp.98-106
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• 2024

Advanced packaging is emerging as a core technology owing to the increasing demand for multifunctional and highly integrated semiconductors to achieve low power and high performance following digital transformation. It may allow to overcome current limitations of semiconductor process miniaturization and enables single packaging of individual devices. The introduction of advanced packaging facilitates the integration of various chips into one device, and it is emerging as a competitive edge in the industry with high added value, possibly replacing traditional packaging that focuses on electrical connections and the protection of semiconductor devices.

• 대한가정학회지
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• 제50권7호
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• pp.67-79
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• 2012

This study analyzed the characteristics of morphing in fashion design through the documentaries on morphing and fashion. The characteristics of morphing in fine art, media, and design area were categorized as reversible metamorphosis, sequential dissolve and blurring of interpolation boundaries. The results were as follow in fashion design. Reversible metamorphosis showed an automatic silhouette transformation by remote control, the metamorphosis of folding method by wearer's own movements and the automatic silhouette transformation by the air pressurizing method. It represented the thoughts of omnipotence as in the feeling of the magical world, the human desire for control in life, the rationalization of magical thinking and imaginative power, the creation of a new dress space and the extension of dress function. Sequential dissolve showed juxtaposition in the same area by the time order, juxtaposition in virtual space through the computer graphics, the series of fashion photography by steel cut of the dress making process and the blending of digital film and fashion design. It represented the approach for the storytelling of fashion show, implication of creative fashion design process and the creation of organic forms and the feeling of fantasy through artificial technology. The blurring of interpolation boundary showed an overlay of different fabrics with transparent boundaries, an overlay of different patterns with transparent boundaries and the blending of fabrics through the visual mixing of color. It represented the obfuscation of the object, the connotation of the space order, the connotation of the extensive and various meanings and the integrative property of objects.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.134-134
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• 2009

In this work, we report that crystallization speed as well as the electrical and optical properties about the N-doped $Ge_2Sb_2Te_5$ thin films. The 200-nm-thick N-doped $Ge_2Sb_2Te_5$ thin film was deposited on p-type (100) Si and glass substrate by RF reactive sputtering at room temperature. The amorphous-to-crystalline phase transformation of N-doped $Ge_2Sb_2Te_5$ thin films investigated by X-ray diffraction (XRD). Changes in the optical transmittance of as-deposited and annealed films were measured using a UV-VIS-IR spectrophotometer and four-point probe was used to measure the sheet resistance of N-doped $Ge_2Sb_2Te_5$ thin films annealed at different temperature. In addition, the surface morphology and roughness of the films were observed by Atomic Force Microscope (AFM). The crystalline speed of amorphous N-doped $Ge_2Sb_2Te_5$ films were measured by using nano-pulse scanner with 658 nm laser diode (power : 1~17 mW, pulse duration: 10~460 ns). It was found that the crystalline speed of thin films are decreased by adding N and the crystalline temperature is higher. This means that N-dopant in $Ge_2Sb_2Te_5$ thin film plays a role to suppress amorphous-to-crystalline phase transformation.

• 한국전기전자재료학회논문지
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• 제21권7호
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• pp.585-593
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• 2008

In this work, we report several experimental data capable of evaluating the phase transformation characteristics of GeSbTe pseudobinary thin films comprehensively utilized as phase change materials. The phase transformation of the GeSbTe thin films was confirmed by XRD measurement from amorphous to hexagonal structure via fee structure except for $Ge_8Sb_2Te_{11}$. In addition, X-ray photoelectron spectra analysis revealed to weaken Ge-Te bond for $Ge_2Sb_2Te_5$ and to strengthen the bonds of all elements for $Ge_8Sb_2Te_{11}$ during the amorphous to crystalline transition. The values of optical energy gap $(E_{OP})$ were around 0.71 and 0.50 eV and the slopes of absorption in extended region (B) were ${\sim}5.1{\times}10^5$ and ${\sim}10{\times}10^5cm^{-1}{\cdot}V^{-1}$ for the amorphous and fcc-crystalline structures, respectively. Finally, the kinetics of amorphous-to-crystalline phase change on the GeSbTe films was characterized using a nano-pulse scanner with 658-nm laser diode (power; $1{\sim}17$ mW, pulse duration; $10{\sim}460$ ns).

• 한국인쇄학회지
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• 제23권1호
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• pp.65-75
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• 2005

An accurate characterization of the display device is essential for better color matching. The calibration and characterization process in display device is needed to transform the device dependent color to the device independent color. The process of characterization performs a linearization and transforms the linearized values into the CIE XYZ tristimulus values. The purposes of this paper is to propose optimal color transformation method for accurate reproduction of original copy in display device and to explain the propriety of transformation method using specific variable for the power of gradation expression.