• Journal of the Optical Society of Korea
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• 제13권2호
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• pp.245-250
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• 2009

We propose a digital holographic interference analysis method based on a 2-frame phase-shifting technique for measuring an optical mirror surface. The technique using 2-frame phase-shifting digital interferometry is more efficient than multi-frame phase-shifting techniques because the 2-frame method has the advantage of a reduced number of interferograms, and then takes less time to acquire the wanted topography information from interferograms. In this measurement system, 2-frame phase-shifting digital interferograms are acquired by moving the reference flat mirror surface, which is attached to a piezoelectric transducer, with phase step of 0 or $\pi$/2 in the reference beam path. The measurements are recorded on a CCD detector. The optical interferometry is designed on the basis of polarization characteristics of a polarizing beam splitter. Therefore the noise from outside turbulence can be decreased. The proposed 2-frame algorithm uses the relative phase difference of the neighbor pixels. The experiment has been carried out on an optical mirror which flatness is less than $\lambda$/4. The measurement of the optical mirror surface topography using 2-frame phase-shifting interferometry shows that the peak-to-peak value is calculated to be about $0.1779{\mu}m$, the root-mean-square value is about $0.034{\mu}m$. Thus, the proposed method is expected to be used in nondestructive testing of optical components.

• 한국전자파학회논문지
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• 제12권5호
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• pp.777-786
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• 2001

본 논문에서는 64-QAM 디지털 무선 전송장치에 적용할 목적으로 주파수 선택적 페이딩 대책 중의 하나인 디지털 기울기 등화기의 원리, 채널 모델링 및 디지털 구현방법을 분석하였다. 또한 복소 13-탭 시간영역의 적응 등화기 칩과 연동시의 성능분석을 수치계산으로 수행하였으며, 장치의 signature 특성을 통과대역 가장자리에서 약 4.5 dB 개선시킬 수 있음을 보였다. 그리고 디지털 기울기 등화기의 모델링에 대한 한계, 동작 자파수, 제어계수, 신호의 constellation, 장치의 성능에 대한 다양한 결과도 검토하였다. 끝으로 61 MHz 클럭까지 동작시험을 검증한 디지털 기울기 등화기의 칩에 대한 기능을 소개한다.

• 대한공간정보학회지
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• 제18권2호
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• pp.131-138
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• 2010

서울시의 건축물 정보를 관리하기 위하여 항공사진을 촬영하고 판독을 실시하여 판독현황도를 제작하고 있다. 그러나 판독현황도는 인쇄된 형태이며 수기로 제작되어 많은 오류를 포함하고 있으며, 갱신에도 어려움이 많다. 본 연구에서는 판독현황도의 수치화를 수행하기 위하여 도면 스캐닝에 의한 방법, 정사영상 및 진정사영상을 활용하는 방법, 수정도화에 의한 방법, LiDAR 자료를 이용하는 방법 등을 적용하고 비교 분석하였다. 본 연구를 통하여 수치수정도화에 의한 수치 판독현황도를 제작하는 것이 건축물 정보의 정확도와 경제성 측면에서 타당한 방법임을 제안할 수 있었다.

• 대한치과의사협회지
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• 제56권7호
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• pp.366-374
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• 2018

Purpose : The purpose of this study was to compare the marginal fit of monolithic zirconia restorations fabricated form the conventional and the digital impression technique. Materials and methods : Ten patients were restored with monolithic zirconia restorations fabricated from the digital and the conventional impression technique. Before definitive insertion, silicone replicas were produced from all twenty crowns. The silicone replicas were cut in three sections; each section was evaluated at two points. The measurement was carried out by using a measuring microscope (Olympus BX 51) and I-Solution. Data from the silicone replica scores were analyzed by Shapiro-Wilk test for normal distribution and the t-test for equality of two population's mean. All tests were performed with ${\alpha}-level$ of 0.05. Results : The average marginal gaps of monolithic zirconia restorations were $133.81{\pm}36.46{\mu}m$ for the conventional impression technique, $90.07{\pm}9.47{\mu}m$ for the digital impression technique. No statistical differences were found between the two impression techniques Conclusion : Both prostheses presented clinically acceptable results with comparing the marginal fit.

• 인터넷정보학회논문지
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• 제15권2호
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• pp.143-147
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• 2014

본 논문에서는 디지털 라디오 표준인 DRM(Digital Radio Mondiale) 및 DRM+(Digital Radio Mondiale Plus) 시스템을 이더넷모드에서 분석할 수 있는 다중화분산접속(MDI, Multiplex Distribution Interface) 분석기를 설계한다. 제안하는 MDI 분석기는 메모리 공유 기술을 가진 공통 블록 모듈을 사용하여 MDI 패킷들의 부하를 감소시키며, 차세대 디지털 라디오 방송시스템을 위해 수신된 MDI 패킷을 통해 IP(Internet Protocol)와 DRM/DRM+ 시스템의 FAC(Fast Access Channel)/SDC(Service Description Channel) 구성정보를 확인할 수 있다.

• 한국군사과학기술학회지
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• 제22권3호
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• pp.332-340
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• 2019

Electronic warfare systems are needed to be advantageous in the modern war. Many radar threat signals with various frequency spectrums and complicated techniques exist. For detecting the threats, a receiver with wide and narrow-band digital processing is needed. To process a wide-band searching mode, a polyphase filter bank has become the architecture of choice to efficiently detect threats. A polyphase N-path filter aligns the re-sampled time series in each path, and a discrete Fourier transform aligns phase and separates the sub-channel baseband aliases. Multiple threats and CW are detected or rejected when the signals are received in different sub-channels. And also, to process a narrow-band precision mode, a direct down converter is needed to reduce aliasing by using a decimation filter. These digital logics are designed in a FPGA. This paper shows how to design and develop a wide and narrow-band digital receiver that is capable to detect the threats.

• 전기전자학회논문지
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• 제23권3호
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• pp.988-993
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• 2019

지난 수십 년간 반도체 업계에서는 반도체 소자의 성능을 높이고 높은 밀도로 반도체 소자를 칩 위에 집적하기 위해 끊임없이 그 크기를 축소해 왔다. 하지만, 게이트 제어의 감소, 높아진 누설 전류, 그리고 단 채널 효과와 같은 다양한 문제점에 직면하면서 이를 극복할 수 있는 차세대 반도체에 점점 더 많은 관심을 보이고 있다. 본 논문에서는 다음 반도체 세대를 이끌 후보로 관심을 받고 있는 CNTFET(Carbon NanuTube Field Effect Transistor)을 활용하여 디지털 회로를 디자인하는 방법에 대해 논하고자 한다. CNTFET이 분명 구조적으로 기존 MOSFET과 다른 구조를 가진 만큼, CNTFET을 활용하여 디지털 회로를 디자인할 때, 기존 디지털 회로 기법을 어떻게 활용할 수 있는지 자세히 알아보고 시뮬레이션을 통해 두 소자의 성능 차이를 확인해 보고자 한다.

• 한국의류학회지
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• 제45권1호
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• pp.200-216
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• 2021

This article considers short-form fashion videos as distinguished from fashion films, defines the concept, details the expressive characteristics of short-form fashion video, and reveals the method of producing it. For the methodology, a literature review was conducted to derive the concept and expression techniques. A case study was also performed to define the expressive characteristics. Five short-form fashion videos were also produced based on the results. The final results are as follows. First, short-form fashion video was defined as a fashion medium on the purpose of fashion communication within 60 seconds and classified by three digital image formats. Second, the result of analyzing the expression of the short-form fashion video shows the simplicity and reconstitution, characterization and remediation, borderless and expansion, and synesthesia trigger of the fashion image. Third, five short-form fashion videos were produced based on the theme of the digital garden. It shows that the short-form fashion video intensively expresses the content as a medium whose sensational expression is more prominent than the composition of the story by the short running time that reflects the taste of digital mainstream.

• International Journal of Advanced Culture Technology
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• 제11권3호
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• pp.302-309
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• 2023

This study aimed to develop a VR-based digital therapeutic intervention for the diagnosis and treatment of ADHD. The research combined medical data with virtual reality technology to develop an algorithm for ADHD diagnostic scales and implemented a VR-based digital therapeutic platform using a head-mounted display (HMD). This platform can be used for the diagnosis and treatment of ADHD in children and adolescents. Additionally, we four VR games were developed, including archery timing, Antarctic exploration, grocery shopping, and rhythm-based drumming(RBD), incorporating various psychiatric treatment techniques based on cognitive-behavioral therapy(CBT). To evaluate the usability of this digital therapeutic intervention, a group of experts specialized in counseling psychology participated in the study. The evaluations received highly positive feedback regarding the ability to access the system menu while wearing the HMD, the consistency of terminology used in menus and icons, the usage of actual size for 3D graphic elements, and the support for shortcut key functionality. The assessments also indicated that the games could improve attention, working memory, and impulse control, suggesting potential therapeutic effects for ADHD. This intervention could provide a daily treatment method for families experiencing financial constraints that limit hospital-based therapies, thereby reducing the burden.

• 패션비즈니스
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• 제27권5호
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• pp.108-120
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• 2023

Recently, interest in eco-friendliness and sustainability has been increasing due to the rapid progress of fast fashion and the crisis of sudden environmental changes after COVID-19. This study aims to develop upcycling textiles and express product design using digital 3D to realize a sustainable fashion industry and present environmental aspects, diversity, creativity, and new directions in fashion industry design. The research method is to develop and pattern upcycling textile designs by applying weaving techniques with waste materials. It uses the developed upcycling textile design in digital 3D to incorporate it into clothing fashion and shows the utility and practicality of upcycling textile design. As a result of the study, the appearance is realistic when outputting DTP of upcycling textile design. It endures without loosening or tearing, making it a durable and creatively expressive fashion item. Texpro 3D mapping reduces the time and cost of making actual sample fabric. Upcycling textile design and 3D CLO virtual clothing are combined to produce actual clothing samples, resulting in zero waste reduction due to cutting and sewing. This study anticipates actively and continuously advancing the development of upcycling textile design and digital 3D in terms of ethics and the environment.