• 제목/요약/키워드: high-frequency core

검색결과 480건 처리시간 0.027초

Image Restoration and Object Removal Using Prioritized Adaptive Patch-Based Inpainting in a Wavelet Domain

  • Borole, Rajesh P.;Bonde, Sanjiv V.
    • Journal of Information Processing Systems
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    • 제13권5호
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    • pp.1183-1202
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    • 2017
  • Image restoration has been carried out by texture synthesis mostly for large regions and inpainting algorithms for small cracks in images. In this paper, we propose a new approach that allows for the simultaneous fill-in of different structures and textures by processing in a wavelet domain. A combination of structure inpainting and patch-based texture synthesis is carried out, which is known as patch-based inpainting, for filling and updating the target region. The wavelet transform is used for its very good multiresolution capabilities. The proposed algorithm uses the wavelet domain subbands to resolve the structure and texture components in smooth approximation and high frequency structural details. The subbands are processed separately by the prioritized patch-based inpainting with isophote energy driven texture synthesis at the core. The algorithm automatically estimates the wavelet coefficients of the target regions of various subbands using optimized patches from the surrounding DWT coefficients. The suggested performance improvement drastically improves execution speed over the existing algorithm. The proposed patch optimization strategy improves the quality of the fill. The fill-in is done with higher priority to structures and isophotes arriving at target boundaries. The effectiveness of the algorithm is demonstrated with natural and textured images with varying textural complexions.

Hall Effect and Resistivity of Amorphous $Fe_{83-x}Zr_{7}B_{10}Nb_{x}$ Alloys

  • Lee, Soo-Hyung;Yu, Seong-Cho;Xu, Jun-Hau;Rao, K.V.;Noh, Tae-Hwan;Kang, Il-Koo;Rhie, Kungwon
    • 한국자기학회지
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    • 제5권5호
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    • pp.841-845
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    • 1995
  • The effect of small addition of Nb on the electrical resistivity and Hall coeffcient of the amorphous $Fe_{83}Zr_{7}B_{10}$ alloy and annealed ones ones below the crystallization temperature were investigated, which has been considered to be suitable for high frequency core material. At room temperature, their resistivities $\rho$ and the spontaneous Hall coeffcients $R_{s}$ are $~1.6\;{\mu}{\Omega}m$ and $~3{\times}10^{-8}m^{3}/As$, respectively. $R_{s}$ and $\rho$ are decreased with increasing temperature from 100 K to room temperature. Side-jump effect was adopted to analyze the effect of the small variation of conentration and annealing. The quantity of $R_{s}/{\rho}^{2}$ at room temperature, which is directly related to the electronic structure of the mother alloy, remained almost a constant except as quenched one as it can be predicted from the side-jump effect. The unexpected temperature dependence of $R_{s}/{\rho}^{2}$ measured at low fields much below Tc is left as a question.

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HALL EFFECT AND RESISTIVITY OF AMORPHOUS $Fe_{83-x}Zr_{7}B_{10}Nb_{x}$ ALLOYS

  • Lee, Soo-Hyung;Yu, Seong-Cho;Xu, Jun-Hau;Rao, K.V.;Noh, Tae-Hwan;Kang, Il-Koo;Rhie, Kungwon
    • 한국자기학회지
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    • 제5권5호
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    • pp.772-777
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    • 1995
  • The effect of small addition of Nb on the electrical resistivity and Hall coefficient of the amorphous $Fe_{83}Zr_{7}B_{10}$ alloy and annealed ones below the crystallization temperature were investigated, which has been considered to be suitable for high frequency core material. At room temperature, their resistivities $\rho$ and the spontaneous Hall coefficients $R_{s}$ are $~1.6\;{\mu}{\Omega}m$ and $~3{\times}10^{-8}m^{3}/As$, respectively. $R_{s}$ and $\rho$ are decreased with increasing temperature from 100 K to room temperature. Side-jump effect was adopted to analyze the effect of the small variation of concentration and annealing. The quantity of $R_{s}/{\rho}^{2}$ at room temperature, which is directly related to the electronic structure of the mother alloy, remained almost a constant except as quenched one as it can be predicted from the side-jump effect. We suggested the temperature dependence of $R_{s}/{\rho}^{2}$ can be compared to Ms{T}.

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MAGNETIC PROPERTIES OF MELT-SPUN $F_{86-x}Al_{4}B_{10}Zr_{x}$ AMORPHOUS ALLOYS

  • Kim, K.J.;Park, J.Y.;Kim, K.Y.;Lee, J.S.;Noh, T.H.
    • 한국자기학회지
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    • 제5권5호
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    • pp.487-490
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    • 1995
  • With the object of developing a new magnetic core materials for high frequency use, the crystallization behaviors and the soft magnetic properties of amorphous $F_{86-x}Al_{4}B_{10}Zr_{x}\;(5{\leq}x{\leq}10\;at%)$ alloys subjected to annealing treatment at wide temperature range were investigated. For optimally annealed $Fe_{86-x}Al_{4}B_{10}Zr_{x}$ alloys in amorphous state, rather good soft magnetic properties of ${\mu}_{e}=17000~25000,\;H_{c}=20~30$ mOe and $B_{10}{\geq}0.6$ T are obtained. However, as the alloys crystallize, the soft magnetic properties are largely dergely deteriorated, which is attributed principally to the narrow temperature gap between $T_{x1}$ and $T_{x2}$, which allows the nearly co-precipitation of bcc phase and Fe-B compounds in incipient crystallization stage.

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Co-occurrence Network Analysis of Keywords in Geriatric Frailty

  • Kim, Youngji;Jang, Soong-nang;Lee, Jung Lim
    • 지역사회간호학회지
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    • 제29권4호
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    • pp.429-439
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    • 2018
  • Purpose: The aim of this study is to identify core keyword of frailty research in the past 35 years to understand the structure of knowledge of frailty. Methods: 10,367 frailty articles published between 1981 and April 2016 were retrieved from Web of Science. Keywords from these articles were extracted using Bibexcel and social network analysis was conducted with the occurrence network using NetMiner program. Results: The top five keywords with a high frequency of occurrence include 'disability', 'nursing home', 'sarcopenia', 'exercise', and 'dementia'. Keywords were classified by subheadings of MeSH and the majority of them were included under the healthcare and physical dimensions. The degree centralities of the keywords were arranged in the order of 'long term care' (0.55), 'gait' (0.42), 'physical activity' (0.42), 'quality of life' (0.42), and 'physical performance' (0.38). The betweenness centralities of the keywords were listed in the order of depression' (0.32), 'quality of life' (0.28), 'home care' (0.28), 'geriatric assessment' (0.28), and 'fall' (0.27). The cluster analysis shows that the frailty research field is divided into seven clusters: aging, sarcopenia, inflammation, mortality, frailty index, older people, and physical activity. Conclusion: After reviewing previous research in the 35 years, it has been found that only physical frailty and frailty related to medicine have been emphasized. Further research in psychological, cognitive, social, and environmental frailty is needed to understand frailty in a multifaceted and integrative manner.

4차산업으로 인한 공작기계산업의 새로운 안전문제 (New Safety Issues in the Machine Tool Industry due to the 4th Industry)

  • 박영석
    • 한국안전학회지
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    • 제37권4호
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    • pp.1-10
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    • 2022
  • The purposes of this study were to suggest 1) a future direction for Korea's machine tool industry and 2) how to secure the safety and reliability of emerging intelligent or automated machine tooling. The study concludes that, overseas, the machine tool industry is growing again while promoting innovation by converging with ICT. Accordingly, Korea also promotes ICT innovation to advance the machine tool industry, which is at the core of the national economy. As a result, unlike in the past, the frequency of serious injuries like entrapment accidents has recently decreased, while the proportion of collision accidents has increased. In addition, a new type of accident has become possible. Since ICT is network-based, the distinction between work and rest can become ambiguous; there is a risk of hacking, working hours and places are flexible and there are risk factors for diseases like chronic fatigue due to overload of specific personnel. As robots and automation are introduced, there is also a high probability of problems caused by physical and psychological burdens on system operators and resulting fatigue.

Parametric study on multichannel analysis of surface waves-based nondestructive debonding detection for steel-concrete composite structures

  • Hongbing Chen;Shiyu Gan;Yuanyuan Li;Jiajin Zeng;Xin Nie
    • Steel and Composite Structures
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    • 제50권1호
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    • pp.89-105
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    • 2024
  • Multichannel analysis of surface waves (MASW) method has exhibited broad application prospects in the nondestructive detection of interfacial debonding in steel-concrete composite structures (SCCS). However, due to the structural diversity of SCCS and the high stealthiness of interfacial debonding defects, the feasibility of MASW method needs to be investigated in depth. In this study, synthetic parametric study on MASW nondestructive debonding detection for SCCSs is performed. The aim is to quantitatively analyze influential factors with respect to structural composition of SCCS and MASW measurement mode. First, stress wave composition and propagation process in SCCS are studied utilizing 2D numerical simulation. For structural composition in SCCS, the thickness variation of steel plate, concrete core, and debonding defects are discussed. To determine the most appropriate sensor arrangement for MASW measurement, the effects of spacing and number of observation points, along with distances between excitation points, nearest boundary, as well as the first observation point, are analyzed individually. The influence of signal type and frequency of transient excitation on dispersion figures from forwarding analysis is studied to determine the most suitable excitation signal. The findings from this study can provide important theoretical guidance for MASW-based interfacial debonding detection for SCCS. Furthermore, they can be instrumental in optimizing both the sensor layout design and signal choice for experimental validation.

철계 비정질 합금 분말코아의 자기적 특성에 미치는 분말 제조방식의 영향 (Effects of the Powder Preparation Method on the Magnetic Properties of Fe-based Amorphous Alloy Powder Cores)

  • 노태환;최혁열
    • 한국자기학회지
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    • 제15권3호
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    • pp.191-197
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    • 2005
  • 철계 비정질 합금 리본을 분쇄한 뒤 상온 압축성형을 통하여 분말코아를 제조할 때 로터밀과 볼밀의 두 가지 분말제조 공정을 사용하여 만든 분말의 형상을 관찰하고, 또 이들을 이용한 분말코아의 자기적 및 전기적 특성과 미세구조를 조사하였다. 로터밀을 사용한 경우 실효투자율의 크기는 볼 밀링한 경우보다 낮았으나 이의 주파수 의존성 및 품질계수는 볼밀의 경우보다 우수하였으며 자심손실 또한 더 작았다. 한편 로터밀을 사용하여 만든 분말은 크기가 균일하고 가장자리는 강한 전단가공을 받아 완만한 곡선을 지닌 등축형을 이루고 있는 반면 볼밀을 사용한 경우는 크기가 상대적으로 불규칙하면서 작은 분말이 많고 가장자리는 날카로운 형상을 하고 있었다. 로터밀로 만든 분말코아의 낮은 투자율은 밀링시 심한 전단에 의해 발생하는 큰 내부응력의 축적에 기인하는 것으로 보여진다. 한편 로터 밀링을 통해 만든 분말코아의 경우 투자율은 상대적으로 낮지만 전기저항의 측정 및 미세구조의 관찰로부터 보다 양호한 절연상태가 확보되어 높은 주파수에 이르기까지 투자율이 유지되면서 적은 자심손실이 얻어진 것으로 판단되었다. 분말코아의 자기적 안정성을 나타내는 직류중첩특성 또한 로터밀의 경우가 볼 밀링한 경우보다 우수하였다.

멀티미디어 데이터 처리에 적합한 SIMD MAC 연산기의 설계 (SIMD MAC Unit Design for Multimedia Data Processing)

  • 홍인표;정우경;정재원;이용석
    • 대한전자공학회논문지SD
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    • 제38권12호
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    • pp.44-55
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    • 2001
  • MAC(Multiply and ACcumulate) 연산은 DSP와 멀티미디어 데이터 처리의 핵심이 되는 연산이다. 기존의 DSP 혹은 내장형 프로세서의 MAC 연산기들은 주로 3사이클의 latency를 가지며, 한번에 하나씩의 데이터를 처리하므로 성능에 한계를 보인다. 따라서 고성능의 범용 프로세서들은 SIMD(Single Instruction Multiple Data) 연산을 지원하는 MAC 연산기를 실행 유닛으로 내장하는 추세이다. 하지만 이러한 고성능의 연산기는 고성능 범용 프로세서의 특성상 다양한 동작 모드를 지원해야 하고 clock 주파수가 높아야 하므로 파이프라인 기법을 사용하고 이에 따른 컨트롤이 복잡하여 하드웨어 설계가 까다롭고 면적이 큰 문제가 있다. 본 논문에서는 내장형 프로세서에 적합한 64비트 폭을 갖는 SIMD MAC 연산기를 설계하였다. 한 사이클에 누적연산까지 모두 완료하도록 하여 파이프라인 제어의 필요성을 없앴고, 기존의 Booth 곱셈기 구조에 기반하여 약간의 회로 추가로 SIMD 연산이 가능하도록 하였다.

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고투자율 등방성 자기물질을 이용한 공진형 마그네토미터의 설계 (Design of Resonant-Type Magnetometer Using High Permeability Isotropic Magnetic Material)

  • 임정빈;심영호;안영섭
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2005년도 춘계학술대회 논문집
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    • pp.133-139
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    • 2005
  • 스마트 디지털 콤파스를 구현하기 위하여 고투자율 등방성 자기물질을 이용한 공진형 마그네토미터(RM)을 설계하였다. 코어에 감은 코일의 인덕턴스 L은 코어의 투자율 $\mu(H)$ 에 비례함을 이론적으로 정립하였고, L의 변화는 간단한 슈미트 트리거 회로를 이용하여 주파수로 획득할 수 있었다. 또한, 반도체 스위치를 이용함으로서 회로를 간단히 구성할 수 있고, 온도에 따른 드리프트와 작동점 이동 문제를 해결할 수 있었다. 자기코어는 Metglas사의 2705M이 최적임을 알았고, RM을 이용하여 측정한 값으로 선체영구자기 성분을 구할 수 있음을 확인하였다.

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