• 제목/요약/키워드: digital $(k_0,\

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PRODUCT PROPERTIES OF DIGITAL COVERING MAPS

  • HAN SANG EON
    • Journal of applied mathematics & informatics
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    • 제17권1_2_3호
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    • pp.537-545
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    • 2005
  • The aim of this paper is to solve the open problem on product properties of digital covering maps raised from [5]. Namely, let us consider the digital images $X_1 {\subset}Z^{n_{0}}$ with $k_0-adjacency$, $Y_1{\subset}Z^{n_{1}}$ with $k_3-adjacency$, $X_2{\subset}Z^{n_{2}}$ with $k_2-adjacency$ and $Y_2{\subset}Z^{n_{3}}$ with $k_3-adjacency$. Then the reasonable $k_4-adjacency$ of the product image $X_1{\times}X_2$ is determined by the $k_0-$ and $k_2-adjacency$ and the suitable k_5-adjacency$ is assumed on $Y_1{\times}Y_2$ via the $k_1-$ and $k_3-adjacency$ [3] such that each of the projection maps is a digitally continuous map, e.g., $p_1\;:\;X_1{\times}X_2{\rightarrow}X_1$ is a digitally ($k_4,\;k_1$)-continuous map and so on. Let us assume $h_1\;:\;X_1{\rightarrow}Y_1$ to be a digital $(k_0, k_1)$-covering map and $h_2\;:\;X_2{\rightarrow}Y_2$ to be a digital $(k_2,\;k_3)$-covering map. Then we show that the product map $h_1{\times}h_2\;:\;X_1{\times}X_2{\rightarrow}Y_1{\times}Y_2$ need not be a digital $(k_4,k_5)$-covering map.

4차 산업혁명 디지털 트윈 기술의 품질경영 적용 연구 (Review on the Application of Industry 4.0 Digital Twin Technology to the Quality Management)

  • ;박상찬
    • 품질경영학회지
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    • 제45권4호
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    • pp.601-610
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    • 2017
  • Purpose: Authors observe the digital twin enabled smart factory and/or digital manufacturing processes where Industry 4.0 technologies and quality management principles intersect. In this regard, this study reviews existing research regarding digital twins from the perspective of quality management. Methods: Initially, attention was given to how digital twins are manifested in the Industry 4.0 environment. Then, authors identify quality management elements amongst digital twin models, to align the concept of quality with the functional purpose of digital twins. After introducing specific examples of quality management tools applied to digital twins, the authors extend the domain of quality management into the analysis of multimedia format quality data obtained through machine vision. Results: Inspired by cases on the quality management application to digital twins, the authors suggest a framework for Industry 4.0 quality management. The envisioned suggested framework encompasses 4 dimensions, namely, 4M&1E, an application time window, new methodologies, and enabling technologies. Conclusion: Finally, the authors unfold the emerging trend of digital twin enabled smart factories, while emphasizing the necessity of quality management in conjunction with the introduction of digital twins.

STRONG k-DEFORMATION RETRACT AND ITS APPLICATIONS

  • Han, Sang-Eon
    • 대한수학회지
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    • 제44권6호
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    • pp.1479-1503
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    • 2007
  • In this paper, we study a strong k-deformation retract derived from a relative k-homotopy and investigate its properties in relation to both a k-homotopic thinning and the k-fundamental group. Moreover, we show that the k-fundamental group of a wedge product of closed k-curves not k-contractible is a free group by the use of some properties of both a strong k-deformation retract and a digital covering. Finally, we write an algorithm for calculating the k-fundamental group of a dosed k-curve by the use of a k-homotopic thinning.

인공적 인접면 치아우식증의 구내방사선사진과 디지털 영상의 진단능 평가 (DIAGNOSTIC ABILITY OF THE PERIAPICAL RADIOGRAPHS AND DIGITAL IMAGE IN THE DETECTION OF THE ARTIFICIAL PROXIMAL CARIES)

  • 허민석;유동수
    • 치과방사선
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    • 제24권2호
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    • pp.439-450
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    • 1994
  • Recently, the digital image was introduced into radiological image. The digital image has the power of contrast enhancement, histogram control, and other digitally enhancement. At the point of the resolution, periapical radiograph is superior to the digital image, but enhanced digital procedure improves the diagnostic ability of the digital image. The purpose of this study was to evaluate the diagnostic ability of artificial proximal caries in conventional radiographs, digital radiographs and enhanced digital radiographs (histogram specification). ROC (Receiver Operating Characteristic) analysis and paired t-test were used for the evaluation of detectability, and following results were acquired: 1. The mean ROC area of conventional radiographs was 0.9274. 2. The mean ROC area of unenhanced digital image was 0.9168. 3. The mean ROC area of enhanced digital image was 0.9339. 4. The diagnostic ability of three imaging methods was not significant difference(p>0.05). So, the digital images had similar diagnostic ability of artificial proximal caries to conventional radiographs. If properly enhanced digital image, it may be superior to conventional radiographs.

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Enhanced Lifetime and Efficiency of Organic Light Emitting Diodes

  • Choi, Han-Ho;Kim, Myung-Seop;Park, Sang-Tae;Yang, Joong-Hwan;Kim, Sung-Tae
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2006년도 6th International Meeting on Information Display
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    • pp.1803-1804
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    • 2006
  • In this paper, device performances of organic lightemitting diodes (OLEDs) will be presented for AMOLED and general illumination applications. Various types of advanced devices were developed to enhance the power efficacy and luminous efficiency. Here we also demonstrated longer lifetime AM-OLED structures, which lifetime is about 100 hours until $L/L_0$ reaches 0.99.

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방사선 사진을 이용한 계수 영상의 판독능에 관한 실험적 연구 (AN EXPERIMENTAL STUDY ON THE DETECT ABILITY OF DIGITAL RADIOGRAPHIC IMAGES)

  • 손영순;조봉혜;나경수
    • 치과방사선
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    • 제24권2호
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    • pp.305-316
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    • 1994
  • The comparative detectability of the artificial defects among conventional radiographs, digital images and digital subtraction images was evaluated. The artificial defects were made within spogy bone of 24 unilateral mandibles of adult dogs. The results were as follows: 1. With normal exposure time, the detectability of digital subtraction radiographs was 90.3% which was statistically significant superior to those of conventional radiographs(78.0%) and digital images(75.9%) (p<0.05). 2. With half-exposure time, the detectability of conventional radiographs, digital images and digital subtraction radiographs was 68.4%, 67.3% and 69.9% respectively. There was no statistical significant difference among the detectability of these methods(p>0.05). 3. All radiographic images with normal exposure time showed statistically significant superior detectability to those with half-exposure time(p<0.05). 4. The detectability of digital subtraction radiographs was not linearly related to the standard deviation of the grey levels of reference line(p<0.05).

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Temperature-dependent Luminescence Properties of Digital-alloy In(Ga1-zAlz)As

  • Cho, Il-Wook;Ryu, Mee-Yi;Song, Jin Dong
    • Applied Science and Convergence Technology
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    • 제27권3호
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    • pp.56-60
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    • 2018
  • The optical properties of the digital-alloy $(In_{0.53}Ga_{0.47}As)_{1-z}/(In_{0.52}Al_{0.48}As)_z$ grown by molecular beam epitaxy as a function of composition z (z = 0.4, 0.6, and 0.8) have been studied using temperature-dependent photoluminescence (PL) and time-resolved PL (TRPL) spectroscopy. As the composition z increases from 0.4 to 0.8, the PL peak energy of the digital-alloy $In(Ga_{1-z}Al_z)As$ is blueshifted, which is explained by the enhanced quantization energy due to the reduced well width. The decrease in the PL intensity and the broaden FWHM with increasing z are interpreted as being due to the increased Al contents in the digital-alloy $In(Ga_{1-z}Al_z)As$ because of the intermixing of Ga and Al in interface of InGaAs well and InAlAs barrier. The PL decay time at 10 K decreases with increasing z, which can be explained by the easier carrier escape from InGaAs wells due to the enhanced quantized energies because of the decreased InGaAs well width as z increases. The emission energy and luminescence properties of the digitalalloy $(InGaAs)_{1-z}/(InAlAs)_z$ can be controlled by adjusting composition z.

A Phase-Locked Loop with Embedded Analog-to-Digital Converter for Digital Control

  • Cha, Soo-Ho;Jeong, Chun-Seok;Yoo, Chang-Sik
    • ETRI Journal
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    • 제29권4호
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    • pp.463-469
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    • 2007
  • A phase-locked loop (PLL) is described which is operable from 0.4 GHz to 1.2 GHz. The PLL has basically the same architecture as the conventional analog PLL except the locking information is stored as digital code. An analog-to-digital converter is embedded in the PLL, converting the analog loop filter output to digital code. Because the locking information is stored as digital code, the PLL can be turned off during power-down mode while avoiding long wake-up time. The PLL implemented in a 0.18 ${\mu}m$ CMOS process occupies 0.35 $mm^2$ active area. From a 1.8 V supply, it consumes 59 mW and 984 ${\mu}W$ during the normal and power-down modes, respectively. The measured rms jitter of the output clock is 16.8 ps at 1.2 GHz.

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이진 위상-주파수 검출기와 카운터를 이용한 디지털 위상 고정 루프 회로 설계 (Design of Digital PLL using Binary Phase-Frequency Detector and Counter for Digital Phase Detection)

  • 한종석;윤관;강진구
    • 전기전자학회논문지
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    • 제16권4호
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    • pp.322-327
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    • 2012
  • 본 논문은 이진 위상-주파수 검출기와 카운터를 사용한 새로운 위상-디지털 변환기 구조의 디지털 위상 고정 루프 회로를 제안하였다. 제안한 디지털 위상 고정 루프 회로는 위상-디지털 변환기, 디지털 루프, 디지털 제어 발진기(DCO)로 구성되어 있다. 제안된 위상-디지털 변환기 구조는 일반적인 시간-디지털 변환기(TDC)를 사용하지 않고, 이진 위상 주파수 검출기와 카운터를 사용함으로써 단순한 구조와 적은 면적으로 소비전력을 감소하는 장점을 갖는다. CMOS 0.18um 공정을 사용하여 1.0GHz에서 2.2GHz에 동작하는 디지털 위상 고정 루프 회로를 설계하였고 칩 면적은 $0.096mm^2$을 차지한다. 시뮬레이션 결과 전력소비는 1.65GHz 동작시 16.2mW로 나타났다.

시-촉각 지연이 실감도에 미치는 영향 (The delay effect on reality in visual and haptic presentation)

  • 김종화;황민철;김영주
    • 감성과학
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    • 제11권2호
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    • pp.227-234
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    • 2008
  • 시각과 청각으로 표현된 디지털 콘텐츠가 감각표현을 확장하려는 연구가 활발하다. 최근에는 촉각 표현이 가능한 다양한 촉각 표현 시스템이 개발하여 촉감을 표현하는 디지털 콘텐츠 개발하고 있다. 하드웨어에 의한 촉감각 표현시 다른 감각과의 동기화가 중요한 표현 요소로 대두되고 있다. 본 연구는 햅틱(haptic)표현이 다른 감각에 비해 표현 지연 발생할 경우 실감도에 미치는 영향에 관한 것이다. 시각 및 햅틱 지연 시간을 0.5, 1.0, 2.0, 4.0(초)로 설정하여 각 지연에 대한 실감도 평가를 실시하여 선형 회귀 분석하였다. 촉각 지연 보다 시각 지연에서 실감도와 상관성을 보였으며 지연 시간이 길어질수록 실감도가 떨어지는 것을 볼 수 있었다. 그러므로 사용자는 촉감 표현에 대한 지연이 시각 지연 보다 관대한 것으로 사료된다.

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