• 제목/요약/키워드: CFA

검색결과 478건 처리시간 0.032초

베이어 CFA 카메라를 사용한 다중 스펙트럼 기반 컬러영상 생성 기술 (Multi-spectral Imaging-based Color Image Reconstruction Using the Conventional Bayer CFA)

  • 신정호
    • 방송공학회논문지
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    • 제16권3호
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    • pp.561-565
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    • 2011
  • 본 논문에서는 기존의 베이어 컬러필터 배열 기반의 영상 센서를 사용하는 카메라에서 개선된 컬러 영상을 생성하기 위한 영상 시스템을 제안한다. 제안한 컬러 영상 생성 기술은 두 장의 연속적인 영상(광대역 G채널 필터를 사용한 영상과 색필터를 적용하지 않고 연속적으로 촬영한 영상)으로부터 RGBCY의 다양한 색 정보를 추출하여 디모자이킹을 위한 컬러 영상 보간의 계산은 감소시키며 개선된 색상 정보를 가지는 영상을 얻을 수 있다. 또한 기존의 베이어 CFA 영상센서를 사용하기 때문에 새로운 형태의 CFA를 제작할 필요 없이 다중 스펙트럼 영상을 취득할 수 있는 카메라 시스템으로 확장 가능하다. 마지막으로 본 논문에서 제안한 컬러영상 생성을 위한 카메라 시스템의 성능을 검증하기 위해서 기존의 디모자이킹 기술과 비교하였으며, 그 결과 컬러 중첩 현상이 상당히 개선되었음을 보였다.

유한요소법을 이용한 냉각홴의 진동 및 간섭에 관한 연구 (A Study on Resonance and Interference of a Cooling Fan Assembly by Using FEM)

  • 서종휘;송하종;박태원;김주용;정일호
    • 한국소음진동공학회논문집
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    • 제14권9호
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    • pp.903-909
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    • 2004
  • A CFA(cooling fan assembly) is composed of a fan, motor and shroud, which is at the back of the automotive radiator. By forcing the wind to pass, the CFA controls the cooling performance of the radiator. The noise and vibration of the CFA may be primarily due to the resonance between the CFA and engine. The Interference among the fan, shroud and radiator by deformation is considered when the CFA is designed. In this paper, in order to analyze the structural vibration of the CFA for automobiles, a finite element model of the CFA is established by using a commercial FEM code. After the finite element modeling, the natural frequencies and the mode shapes are obtained from the FE analysis. The natural frequencies are obtained from the vibration test as well. Then, the results of the vibration test are compared with those of the FE analysis. The natural frequencies obtained by experiment have a great similarity to the results from FE model. We have confirmed the validity of the FE model and verify the structural safety for the resonance. The stress and displacements are obtained from FE analysis. We have confirmed the safety for the interference and failure.

Participation of IL-1β in temporomandibular nociception in rats with CFA-induced inflammation

  • Ju, Jin-Sook;Choi, Seung-Ho;Kim, Hye-Jin;Son, Jo-Young;Ahn, Dong-Kuk
    • International Journal of Oral Biology
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    • 제41권3호
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    • pp.125-131
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    • 2016
  • The aim of the present study was to develop an animal model for evaluation of temporomandibular (TMJ) nociception under TMJ inflammation. We also investigated the participation of $IL-1{\beta}$ in inflammation-induced TMJ nociception. Experiments were carried out using male Sprague-Dawley rats. Intra-articular injection of 3% formalin was administered to evaluate hyperalgesia 3 days after CFA injection. Intra-articular injection of 3% formalin did not produce nociceptive behavior in normal rats. Although intra-articular injection of 3 doses of CFA produced TMJ inflammation, only 1:3 diluted CFA produced hyperalgesia when formalin was injected intra-articularly 3 days after CFA injection. Co-administration of IL-1 receptor inhibitor with formalin into the TMJ cavity 3 days after CFA injection was performed. Co-administration of IL-1 receptor inhibitor significantly inhibited formalin-induced hyperalgesia in rats with CFA-induced TMJ inflammation. These results suggested that intra-articular injection of formalin produced hyperalgesia under chronic TMJ inflammation. Moreover, $IL-1{\beta}$ plays an important role in TMJ hyperalgesia under chronic inflammation and blockade of $IL-1{\beta}$ is a potential therapeutic target for inflammatory TMJ pain.

Changes in growth performance, carcass characteristics, and meat properties of Hanwoo steers according to supplementation of composite feed additive

  • Ahn, Jun-Sang;Shin, Jong-Suh;Lee, Chang-Woo;Choi, Wook-Jin;Kim, Min-Ji;Choi, Jang-Gun;Son, Gi-Hwal;Chang, Sun-Six;Kwon, Eung-Gi;Park, Byung-Ki
    • 농업과학연구
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    • 제46권1호
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    • pp.11-25
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    • 2019
  • This study was conducted to evaluate the effects of a composite feed additive (CFA) consisting of vitamin C, vitamin E, selenium, and choline on growth performance, carcass characteristics, and meat properties of Hanwoo steers. Twenty-two late fattening steers were randomly assigned to one of two dietary groups, control (commercial concentrate + rice straw) and treatment (commercial concentrate + rice straw + 50 g of CFA). Average daily gain (ADG) was 4.0% higher in treatment than that in control; however, there was no statistically significant difference. The supplementation of CFA had no effect on overall yield or quality traits of carcass. CFA had no effect on chemical composition, water holding capacity, shear force, cooking loss, or myoglobin values in longissimus muscle; however, the content of ${\alpha}$-tocopherol was increased by supplementation of CFA (p < 0.01). The contents of ${\alpha}$-linolenic acid and n-3 fatty acids were higher in treatment group than in control (p < 0.01). The ratio of n-6/n-3 fatty acids was decreased by supplementation of CFA (p < 0.01). The supplementation of CFA had no effect on pH or thiobarbituric acid reactive substances (TBARS) values in longissimus muscle (raw); however, TBARS (cooked) values were lower in treatment group than in control during refrigerated storage (p < 0.01). Thus, the results indicate that the supplementation of CFA (vitamin C + vitamin E + selenium + choline) had some positive effects on the increase in ${\alpha}$-tocopherol and n-3 fatty in longissimus muscle, without any negative effect on growth performance or carcass characteristics of late fattening Hanwoo steers.

휴대폰의 CFA 패턴특성을 이용한 사진 위변조 탐지 (Automatic Detection of Forgery in Cell phone Images using Analysis of CFA Pattern Characteristics in Imaging Sensor)

  • 심재연;김성환
    • 한국정보처리학회:학술대회논문집
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    • 한국정보처리학회 2010년도 추계학술발표대회
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    • pp.1118-1121
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    • 2010
  • With the advent of cell phone digital cameras, and sophisticated photo editing software, digital images can be easily manipulated and altered. Although good forgeries may leave no visual clues of having been tampered with, they may, nevertheless, alter the underlying statistics of an image. Most digital camera equipped in cell phones employ a single image sensor in conjunction with a color filter array (CFA), and then interpolates the missing color samples to obtain a three channel color image. This interpolation introduces specific correlations which are likely to be destroyed when tampering with an image. We quantify the specific correlations introduced by CFA interpolation, and describe how these correlations, or lack thereof, can be automatically detected in any portion of an image. We show the efficacy of this approach in revealing traces of digital tampering in lossless and lossy compressed color images interpolated with several different CFA algorithms in test cell phones.

Edge-preserving demosaicing method for digital cameras with Bayer-like W-RGB color filter array

  • Park, Jongjoo;Chong, Jongwha
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제8권3호
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    • pp.1011-1025
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    • 2014
  • A demosaicing method for a Bayer-like W-RGB color filter array (CFA) is proposed. When reproducing images from a W-RGB CFA, conventional color separation methods for W-RGB CFA are likely to cause blurring near the edges due to rough averaging using a color ratio of neighboring pixels. Moreover, these methods cannot be applied to real-life digital cameras with W-RGB CFA because the methods were proposed under an ideal situation, W=R+G+B, not a real-life situation, $W{\neq}R+G+B$. To improve edge performance, we propose a method of constant color difference assumption with inversed weight, which uses information from all edge directions for interpolating all missing color channels. The proposed method calculates the correlation between W, R, G, and B to enable its application to real-life digital cameras with W-RGB CFA. Simulations were performed to evaluate the proposed method using images captured from a real-life digital camera with W-RGB CFA. Simulation results shows that we can demosaic by using the proposed algorithm compared with the conventional one in about +34.79% SNR, +11.43% PSNR, +1.54% SSIM and 14.02% S-CIELAB error. Thus, the proposed method demosaics better than the conventional methods.

전침에 의한 CFA유발 통증모델의 NMDA 수용체 의존적 ERK MAPK 발현 변화 (Effects of Electroacupucture on NMDA Receptor-dependent Spinal ERK MAPK Expression in CFA-induced Pain Model)

  • 김하늬;김유리;장지연;최영현;이용태;최병태
    • 동의생리병리학회지
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    • 제24권6호
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    • pp.983-988
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    • 2010
  • The present study aims to investigate a possible mechanism of electroacupuncture (EA) in the spinal dorsal horn that may underlie N-methyl-D-aspartate (NMDA) receptor-associated extracellular signal-regulated kinase (ERK) mitogen-activated protein kinase (MAPK) signaling pathways. The hot plate latency of the ipsilateral hindpaw of EA-treated rats was significantly decreased compared with complete Freund's adjuvant (CFA)-injected ones. The expressions of NR1 and NR2B subuint mRNA of NMDA receptor in the whole L4-5 segments are decreased by CFA treatment, but NR2B subunit was significantly recovered by EA treatment. When we detected the expression of ERK, there were no significant difference between normal and CFA-treated rats with EA or NMDA receptor antagonist MK801. But phosphorylated ERK expressions were markedly induced by CFA, but these inductions were significantly modulated by EA treatment. Although hosphorylation of ERK was also arrested by MK801, these inductions of CFA-injected rats was markedly inhibited only by co-treatment with EA and MK801. Phosphorylated cAMP response element-binding protein (CREB), ERK-related transcriptional factor, showed a significant increase in CFA-treated rats and this increase was slightly inhibited by EA and MK801 treatments. But immunoreaction for phosphorylated CREB were significantly increased by CFA treatment in the superficial laminae of the dorsal horn and these inductions were significantly arrested by co-treatment of EA and MK801. Consequently, the hyperalgesia induced by CFA are associated NMDA receptor and EA and MK801 may showed anti-hyperalgesia via same mechanism for inhibition of ERK and CREB phosphorylation in the dorsal horn.

A Blockade of the Central MAPK Pathway Attenuates Referred Pain in Rats with Complete Freund's Adjuvant -Induced Inflammation of the Temporomandibular Joint

  • Won, Kyoung-A.;Lim, Nak-H.;Lee, Min-K.;Park, Min-K.;Yang, Gwi-Y.;Park, Yoon-Yub;Ahn, Dong-K.;Bae, Yong-C.
    • International Journal of Oral Biology
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    • 제35권3호
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    • pp.83-89
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    • 2010
  • We investigated the role of the central MAPK pathways in extra-territorial (referred) pain resulting from inflammation of the temporomandibular joint (TMJ). Experiments were carried out on male Sprague-Dawley rats weighing 220-280 g. Under anesthesia, these animals were injected with $50\;{\mu}L$ of complete Freund's adjuvant (CFA) into the TMJ using a Hamilton syringe. In the control group, saline was injected into the TMJ. To identify the extent of inflammation of the TMJ, Evans blue dye (0.1%, 5 mg/kg) was injected intravenously at 1, 3, 6, 9, 12 and 15 days after CFA injection. The concentration of Evans blue dye in the extracted TMJ tissue was found to be significantly higher in the CFA-treated animals than in the saline-treated group. Air-puff thresholds in the vibrissa pad area were evaluated 3 days before and at 3, 6, 9, 12, 15 and 18 days after CFA injection into the TMJ. Referred mechanical allodynia was established at 3 days, remained until 12 days, and recovered to preoperative levels at 18 days after CFA injection. This referred mechanical allodynia was observed in contralateral side area. To investigate the role of central MAPK pathways, MAPK inhibitors ($10\;{\mu}g$) were administrated intracisternally 9 days after CFA injection. SB203580, a p38 MAPK inhibitor, significantly attenuated referred mechanical allodynia, as compared with the vehicle group. PD98059, a MEK inhibitor, also reduced CFA-induced referred mechanical allodynia. These results suggest that TMJ inflammation produces extra-territorial mechanical allodynia, and that this is mediated by central MAPK pathways.

탐색적요인분석과 확인적요인분석의 비교에 과한 연구 (The Study on the comparative analysis of EFA and CFA)

  • 최창호;유연우
    • 디지털융복합연구
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    • 제15권10호
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    • pp.103-111
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    • 2017
  • 본 연구는 탐색적 요인분석과 확인적 요인분석에 대한 특성과 그 차이점에 대하여 살펴보고, 동일한 데이터를 활용하여 탐색적 요인분석과 확인적 요인분석의 분석과정 및 결과를 비교분석함으로써 두 방법론의 올바른 이해와 적용에 대하여 알아보고자 한다. 한편, 실증분석 결과는 아래와 같다. 탐색적 요인분석에서는 판별타당도가 저해되는 p.1, p.3이 제거된 반면, 확인적 요인분에서는 집중타당도가 저해되는 p.3가 제거 되었다. 탐색적 요인분석의 경우 다수의 측정변수를 소수의 요인으로 축약하는 분석과정(다소 부족한 이론적배경)인 반면, 확인적 요인분석은 측정변수와 잠재변수들 간의 관계를 파악 및 확인하는 과정(강력한 이론적배경)으로 동일한 데이터를 활용한다 하더라도 두 방법론은 언제든지 다른 결과 값이 도출될 수 있는 바, 데이터의 성격 등에 따라 올바른 방법론의 활용이 요구된다는 시사점을 보여주고 있다.

재(석탄, 목재, 왕겨재)의 특성과 환경보호를 위하여 계분의 첨가 가능성에 관한 연구 (Characteristics of Ash (Coal, Wood and Rice Hull) and Its Potential Use as an Additive in Poultry Manure for Protecting the Environment)

  • 남기홍
    • 한국가금학회지
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    • 제33권1호
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    • pp.65-80
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    • 2006
  • 재는 가축분을 중성화 시키며 토양에 산포하면 악취를 저감시키는 역할을 하며 하천에서 P의 양을 감소시킬 수 있다. 그러므로 본 연구에서는 재의 특성과 이들의 첨가가 가져올 환경적인 이용에 관해서 언급하였다. 재는 아직도 물리적 화학적으로 일정한 정의가 없다 (석탄재-CFA, 목재재-WA, 왕겨재-RHA). 이들 재를 형성하고 있는 조건과 조성에 따라 산도는 6.0이하 그리고 12.5이상까지 이른다. CFA를 분중에 첨가하면 분중에 녹아있는 P의 양이 감소되어 토양에 산포하면 수질을 향상시킨다. WA는 WA 자체에 많은 탄소 원자를 갖고 있기 때문에 분에서 발생하는 냄새를 제거할 수 있다. RHA는 재중에 $20{\sim}60%$ 가량이 실리카이다. 현재까지 CFA, WA 그리고 RHA를 토양에 산포하여 미치는 영향에 대한 연구는 많이 되어 있으므로 앞으로 가축분에 첨가하면 분중의 P과 악취를 낮출 수 있는 연구가 필요하다.