• 제목/요약/키워드: mirror effect

검색결과 225건 처리시간 0.033초

A CMOS Bandgap Reference Voltage Generator for a CMOS Active Pixel Sensor Imager

  • Kim, Kwang-Hyun;Cho, Gyu-Seong;Kim, Young-Hee
    • Transactions on Electrical and Electronic Materials
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    • 제5권2호
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    • pp.71-75
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    • 2004
  • This paper proposes a new bandgap reference (BGR) circuit which takes advantage of a cascode current mirror biasing to reduce the V$\_$ref/ variation, and sizing technique, which utilizes two related ratio numbers k and N, to reduce the PNP BJT area. The proposed BGR is designed and fabricated on a test chip with a goal to provide a reference voltage to the 10 bit A/D(4-4-4 pipeline architecture) converter of the CMOS Active Pixel Sensor (APS) imager to be used in X-ray imaging. The basic temperature variation effect on V$\_$ref/ of the BGR has a maximum delta of 6 mV over the temperature range of 25$^{\circ}C$ to 70$^{\circ}C$. To verify that the proposed BGR has radiation hardness for the X-ray imaging application, total ionization dose (TID) effect under Co-60 exposure conditions has been evaluated. The measured V$\_$ref/ variation under the radiation condition has a maximum delta of 33 mV over the range of 0 krad to 100 krad. For the given voltage, temperature, and radiation, the BGR has been satisfied well within the requirement of the target 10 bit A/D converter.

반도체 포화 흡수체 반사경에 의해 모드 잠금된 Yb:YAG 레이저 출력의 공진기 모드 크기에 대한 의존성 연구 (Dependence of CW Mode Locking on Resonator Mode Size in a Yb:YAG Laser Mode-Locked by a Semiconductor Saturable Absorber Mirror)

  • 김현철;임한범;채동원;김현수
    • 한국광학회지
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    • 제26권6호
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    • pp.312-317
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    • 2015
  • 레이저 공진기 모드 크기가 반도체 포화 흡수체 거울(SESAM)을 이용하여 모드 잠금된 Yb:YAG 레이저의 출력에 주는 영향을 조사하였다. SESAM과 Yb:YAG 매질 위치에서 공진 모드들 크기를 곱한 값이 작을수록 모드 잠금이 안정적으로 발생함을 실험적으로 보였다. 수치적으로 레이저 매질의 열 렌즈 효과와 무관하게 모드 잠금이 이루어지는 공진기 길이 조건이 있음을 확인하였다.

Context-aware Video Surveillance System

  • An, Tae-Ki;Kim, Moon-Hyun
    • Journal of Electrical Engineering and Technology
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    • 제7권1호
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    • pp.115-123
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    • 2012
  • A video analysis system used to detect events in video streams generally has several processes, including object detection, object trajectories analysis, and recognition of the trajectories by comparison with an a priori trained model. However, these processes do not work well in a complex environment that has many occlusions, mirror effects, and/or shadow effects. We propose a new approach to a context-aware video surveillance system to detect predefined contexts in video streams. The proposed system consists of two modules: a feature extractor and a context recognizer. The feature extractor calculates the moving energy that represents the amount of moving objects in a video stream and the stationary energy that represents the amount of still objects in a video stream. We represent situations and events as motion changes and stationary energy in video streams. The context recognizer determines whether predefined contexts are included in video streams using the extracted moving and stationary energies from a feature extractor. To train each context model and recognize predefined contexts in video streams, we propose and use a new ensemble classifier based on the AdaBoost algorithm, DAdaBoost, which is one of the most famous ensemble classifier algorithms. Our proposed approach is expected to be a robust method in more complex environments that have a mirror effect and/or a shadow effect.

실리콘 파브리-페로 파장가변 열광학 필터 (Silicon Fabry-Perot Tunable Thermo-Optic Filter)

  • 박수연;강동헌;김영호;길상근
    • 전기전자학회논문지
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    • 제12권3호
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    • pp.131-137
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    • 2008
  • 실리콘 박막 코팅을 이용한 WDM용 파장가변 실리콘 파브리-페로 열광학 필터를 제안하고 실험하였다. 실리콘 파브리-페로 파장가변 필터는 일반적인 실리콘 웨이퍼를 CMP 공정을 통해 100${\mu}m{\pm}$1%의 두께로 가공하여 양면에 거울면을 갖도록 박막 코팅하고 온도를 변화시키기 위해 PTC 써미스터를 부착하여 제작하였다. 거울면의 형성은 1550nm를 중심 파장을 갖도록 양면에 굴절율이 다른 물질 $SiO_2$($n_{low}$=1.44)와 a-Si($n_{high}$=3.48)을 ${\lambda}$/4의 두께로 증착시켜 2층 박막과 3층 박막의 거울면을 제작하였다. 실험결과, 2층 박막의 경우 FSR이 3.61nm, FWHM이 0.56nm, finesse가 6.4로 나타났고, 3층 박막의 경우 FSR이 3.36nm, FWHM이 0.13nm, finesse가 25.5로 나타났다. 열광학 효과에 의한 파장 이동은 2층 박막 거울을 가진 필터의 경우 온도가 $23^{\circ}C$에서 투과 중심 파장이 1549.73nm $30^{\circ}C$에서 1550.91nm, $60^{\circ}C$에서 1553.46nm로 파장 이동을 하였고, 3층 박막 거울을 가진 필터의 경우는 온도가 $23^{\circ}C$에서 투과 중심 파장이 1549.83nm, $30^{\circ}C$에서 1550.92nm, $60^{\circ}C$에서 1553.07nm로 파장 이동을 하였다.

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Therapeutic Efficacy of Low Frequency Transcranial Magnetic Stimulation in Conjunction with Mirror Therapy for Sub-acute Stroke Patients

  • Cha, Hyun Gyu;Kim, Myoung-Kwon
    • Journal of Magnetics
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    • 제20권1호
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    • pp.52-56
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    • 2015
  • The purpose of the current study was to investigate the effect of repetitive transcranial magnetic stimulation (rTMS) in conjunction with mirror therapy on the balance function of patients with sub-acute stroke hemiparesis. This study was conducted with 36 subjects who were diagnosed with a hemiparesis due to stroke. Participants in the experimental (19 members) and control groups (17 members) received rTMS and sham rTMS during 10 minute sessions each, which were carried out five days per week for four weeks. This was followed by the mirror therapy over 30 minute sessions, which were carried out five days per week for four weeks. Motor recovery was assessed by balance index, dynamic limits of stability, Berg balance scale, and time up go test. The change values of the balance index ($-2.06{\pm}1.99$ versus $-0.41{\pm}1.11$), dynamic limits of stability ($3.68{\pm}2.71$ versus $1.17{\pm}2.38$), and time up go test ($-7.05{\pm}5.64$ score versus $-3.35{\pm}5.30$ score) were significantly higher in the experimental group than in the control group (p < 0.05). At post-test, balance index ($4.08{\pm}1.14$ versus $5.09{\pm}1.04$), dynamic limits of stability ($13.75{\pm}0.60$ versus $11.73{\pm}3.53$), and time up go test ($23.89{\pm}4.51$ versus $28.82{\pm}3.07$) were significantly higher in the experimental group than in the control group (p < 0.05). In the experimental group, significant differences were found in the pre- and post-test scores for the balance index, dynamic limits of stability, Berg balance scale, and time up go test (p < 0.01). In the control group, a significant difference was observed between the pre- and post-test only for the Berg balance scale and time up go test (p < 0.05). These findings demonstrate that the application of 1Hz rTMS in conjunction with mirror therapy can be helpful in improving the balance function of patients with sub-acute stroke hemiparesis, and this may be used as a practical adjunct to routine rehabilitation therapy.

동의보감·내경편 독활(獨活)의 용법을 통해 본 한의학 기초와 임상의 연계 교육 방안 (Bridging Basic Knowledge and Clinical Practice in the Education of Traditional Korean Medicine: A case of Pubescent Angelica usages in Internal Bodily Elements section, Treasured Mirror of Eastern Medicine)

  • 홍지성;강인혜;이영미;이훈연;강연석
    • 한국의사학회지
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    • 제33권1호
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    • pp.1-9
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    • 2020
  • Pubescent Angelica is generally used in musculoskeletal diseases of lower extremity, itching, external contraction (外感) and furuncle, with the effect of dispelling wind, draining dampness, dispersing the external (解表) and stopping pain. The disease parts of Treasured Mirror of Eastern Medicine (東醫寶鑑) contain 121 examples of the usage of Pubescent Angelica. Cases of musculoskeletal diseases and itching are mainly in the External Bodily Elements section (外形篇), and those of external contraction and furuncle are mainly in the Miscellaneous Disorder section (雜病篇). Internal Bodily Elements section (內景篇) has 10 prescriptions that involve Pubescent Angelica, in Dreams (2), Voice (1), Uterus (4), Parasites (1), and Feces (2) chapters. Their specific symptoms are insomnia and sleep paralysis (Dreams), loss of voice due to external contraction (Voice), uterine hemorrhage (Uterus), phthisis (Parasites), and constipation and diarrhea (Feces). It is not easy for students beginning their clinical training to link the effects of Pubescent Angelica and its actual usage, especially in the area of internal medicine. By Analyzing the whole cases of Pubescent Angelica in the Treasured Mirror, we found various usages out of reach of basic knowledge of the herb. Such method can be utilized not only in developing herbal knowledge-based products, but also in improving Korean medicine education, by enhancing the occupational competency bridging basic and clinical knowledge.

"동의보감"과 "향약집성방"의 "증류본초" 활용 -"향약집성방" "향약본초", "동의보감" "탕액편"을 중심으로- (Applications of Classified Emergency Materia Medica (證類本草) on Treasured Mirror of Eastern Medicine (東醫寶鑑) and Compendium of Prescriptions from the Countryside (鄕藥集成方))

  • 오재근
    • 대한한의학원전학회지
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    • 제24권5호
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    • pp.107-118
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    • 2011
  • Classified Emergency Materia Medica is a pharmacopoeia published by the government of the Song(宋) dynasty. After publishment, it had a decisive effect on East-Asian herbology of China, Korean & Japan. Sakae Miki(三木榮), Tameto Okanisi(岡西爲人) wrote papers on the subjects of type, publishing process, bibliographic terms of Classified Emergency Materia Medica published in the early and middle years of Joseon Dynasty. Moreover, Sakae Miki claimed that Classified Emergency Materia Medica from China had been a standard of herbology of Joseon Dynasty since its publishment, and herbology based on materia medica from countryside(鄕藥) also had occupied a part of herbology in Joseon Dynasty. Nevertheless the specific influences, from Classified Emergency Materia Medica to the medical books of Joseon Dynasty which established the herbology based on materia medica from countryside has never been handled so far. So I would like to investigate the influence of Classified Emergency Materia Medica to Joseon Dynasty, through a comparison with literature review. The main literatures for comparison are two representative medical books of Joseon Dynasty, Compendium of Prescriptions from the Countryside(1433) & Treasured Mirror of Eastern Medicine(1613), especially focusing on the pharmacognostic parts. The main comparing points on researching literatures will be the following: publication year of books; order of herbs; and quotations. This paper will show which edition of Classified Emergency Materia Medica was utilized to publish two medical books of Joseon Dynasty, and the process how Korean herbology based on materia medica from countryside was transformed after accepting Chinese herbology.

노인을 위한 음성인식 기반의 스마트 미러 시스템 구현 (Implementation of speech recognition based smart mirror system for the elderly)

  • 정원석;권구현;서정욱;송명규
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2017년도 춘계학술대회
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    • pp.727-729
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    • 2017
  • 통계청과 보건복지가족부에 따르면 우리나라는 65세 이상 고령인구 비율이 세계 평균치보다 높게 추정되며 이미'고령화 사회(Ageing Society)'에 접어든 것으로 나타났다. 또한, 예상보다 이른 시기에 정보사회에 도달하여 국민들의 삶의 질이 개선되었을 것으로 추정된다. 그러나 고령층은 젊은 층과 달리 새로운 기계에 선뜻 접근하기 어려워 정보의 접근 및 이용에 있어 뚜렷한 차이를 보이고 있어 세대 간 정보 격차(Digital Divide) 현상을 야기 시키고 있다. 이러한 현상을 해결하기 위해 고령층을 위한 음성인식 기반의 스마트 미러 시스템을 구현하였다. 구현한 시스템은 음성인식을 통하여 조명제어 및 날씨, 지하철 시간 정보 조회 서비스를 제공할 수 있다. 구현한 시스템을 통하여 고령층에게 새로운 기계에 대한 접근 용이성을 제공하여 새로운 시대 변화에 동참하는 느낌을 주고 정보를 얻어 생활이 편리하게 만들어 준다는 효과가 기대된다.

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"의종금감.외과심법요결(醫宗金鑑.外科心法要訣)"의 경락학적 이해 - "자구심법요결(刺灸心法要訣)"과 비교 고찰을 중심으로 - (The Understanding of Meridian in "Woe Gwa Sim Beop Yo Gyeol" of "The Golden Mirror of Medicine" - Focus on Comparative Study with "Ja Gu Sim Beop Yo Gyeol" -)

  • 이양석;권선오;김승태;박히준;함대현;이혜정
    • Korean Journal of Acupuncture
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    • 제29권1호
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    • pp.47-55
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    • 2012
  • Objectives : The aim of this study was to understand the meaning of meridian in "Woegwasimbeopyogyeol (WGS)" of "The Golden Mirror of Medicine (GMM)". Methods : We compared the meaning of meridian in WGS with in Jagusimbeopyogyeol (JGS) of GMM. Results : Objectivity and clearness is obtained by inserting the meridian and collateral diagram and the partially expanded diagram in WGS and JGS. The meridian song (a quatrain with seven) in WGS is placed at the beginning of the chapter, indicating its importance. Kihyeoldaso of 12 meridians is detailed in WGS, so as to reduce the harmful effect when doctors diagnose, treat and prognose. It is important to understand the meaning of meridian When doctors treat carbunculosis. The symptoms of a disease is classified by parts and shown in diagram, which can play an important role in diagnosis. Conclusions : The WGS follows the meanings of meridian and the complementary structure in JGS.

폴리곤 미러를 이용한 3D 프린터에 관한 연구 (A Study on 3D Printer Using Polygon Mirror)

  • 권동현;허성욱;임지용;오암석;김완식
    • 한국정보통신학회:학술대회논문집
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    • 한국정보통신학회 2016년도 추계학술대회
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    • pp.142-144
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    • 2016
  • 최근 제조 분야의 미래 유망기술이자, 막대한 파급효과를 유발할 것으로 예상되는 3D 프린터에 대한 관심이 급증하고 있으며, 3D 프린터 제품 가격의 하락에 따른 다양한 형태의 제품 보급이 확산되고 있다. 그러나 현재 보급되고 있는 개인용 3D 프린터는 기술적 성능의 한계점에 따라 높은 가공 정밀도를 요구하지 않는 단순한 형태의 사출물 출력에 사용되고 있으며 소비자 만족도가 매우 낮다. 따라서 본 논문에서는 기존 3D 프린터의 한계점을 극복하기 위해 정밀도가 높은 SLA 방식의 3D 프린터 사출방식과 사무용 레이저 프린터의 LSU(Laser Scanning Unit)를 융합한 폴리곤 미러 스캐닝 방식의 3D프린터를 제안하였다. 제안하는 3D프린터는 정밀도와 제조 속도를 개선하여 기존의 보급형 3D프린터를 대체할 수 있을 것으로 기대한다.

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