• Title/Summary/Keyword: mirror effect

Search Result 225, Processing Time 0.036 seconds

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
    • /
    • v.5 no.2
    • /
    • pp.71-75
    • /
    • 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.

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

  • Kim, Hyun Chul;Lim, Han Bum;Chae, Dong Won;Kim, Hyun Su
    • Korean Journal of Optics and Photonics
    • /
    • v.26 no.6
    • /
    • pp.312-317
    • /
    • 2015
  • We investigate the effect of laser-resonator mode size on the output of a Yb:YAG laser that is mode-locked by a semiconductor saturable absorber mirror (SESAM). We demonstrate that the smaller the product of the mode sizes at a SESAM and at a Yb:YAG crystal, the more stable the mode-locked output is. Also, we found numerically that there is a resonator length at which the mode-locked output occurs, regardless of the thermal lens effect of a Yb:YAG.

Context-aware Video Surveillance System

  • An, Tae-Ki;Kim, Moon-Hyun
    • Journal of Electrical Engineering and Technology
    • /
    • v.7 no.1
    • /
    • pp.115-123
    • /
    • 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.

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

  • Park, Su-Yeon;Kang, Dong-Heon;Kim, Young-Ho;Gil, Sang-Keun
    • Journal of IKEEE
    • /
    • v.12 no.3
    • /
    • pp.131-137
    • /
    • 2008
  • A silicon Fabry-Perot tunable thermo-optic filter for WDM using the thin film silicon coating is proposed and experimented. The filter is implemented by using the CMP process and polishing both sides of the commercial silicon wafer with normal thickness of 100${\mu}m{\pm}$1%. The filter also has 2-layer or 3-layer dielectrics thin film coating mirror which are alternated ${\lambda}$/4 layers of $SiO_2$($n_{low}$=1.44) and a-Si($n_{high}$=3.48) for the central wavelength of 1550nm by RF sputtering. The experiment shows that FSR is 3.61nm and FWHM is 0.56nm and the finesse is 6.4 for 2-layer mirror with the reflection of 61%, and that FSR is 3.36nm and FWHM is 0.13nm and the finesse is 25.5 for 3-layer mirror with the reflection of 89%. According to thermo-optic effect, the transmitted central wavelength of 1549.73nm at $23^{\circ}C$ is shifted to 1550.91nm at $30^{\circ}C$ and 1553.46nm at $60^{\circ}C$ for 2-layer mirror, and the transmitted central wavelength of 1549.83nm at $23^{\circ}C$ is shifted to 1550.92nm at $30^{\circ}C$ and 1553.07nm at $60^{\circ}C$ for 3-layer mirror.

  • PDF

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
    • /
    • v.20 no.1
    • /
    • pp.52-56
    • /
    • 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.

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 (동의보감·내경편 독활(獨活)의 용법을 통해 본 한의학 기초와 임상의 연계 교육 방안)

  • Hong, Jiseong;Kang, Inhye;Lee, Youngmi;Lee, Hoon-Yeon;Kang, Yeonseok
    • The Journal of Korean Medical History
    • /
    • v.33 no.1
    • /
    • pp.1-9
    • /
    • 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.

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) ("동의보감"과 "향약집성방"의 "증류본초" 활용 -"향약집성방" "향약본초", "동의보감" "탕액편"을 중심으로-)

  • Oh, Chae-Kun
    • Journal of Korean Medical classics
    • /
    • v.24 no.5
    • /
    • pp.107-118
    • /
    • 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.

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

  • Jung, Wonseok;Kwon, Guhyeon;Seo, Jeongwook;Song, Myungkyu
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2017.05a
    • /
    • pp.727-729
    • /
    • 2017
  • According to the National Statistical Office and the Ministry of Health and Welfare Family Department, Korea has already estimated that the proportion of the elderly population aged 65 or over is estimated to be higher than the global average, and has already entered the "Aging Society". Moreover, it is estimated that the quality of life of the people improved by reaching the information society earlier than expected. However, unlike young people, elderly people show clear differences in access and use of information that is difficult to access new machines easily and cause intergenerational digital divide phenomenon. In order to solve such a phenomenon, we implemented a speech recognition based smart mirror system for elderly people. The installed system can provide lighting control, weather forecast and subway time information search service of the using voice recognition. Through the implemented system, it is expected that the elderly will have accessibility to new machines, information that gives a feeling of participating in the change of the new era will be obtained and the effect of living convenience will be expected.

  • PDF

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" - ("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 -)

  • Lee, Yang-Seok;Kwon, Sun-Oh;Kim, Seung-Tae;Park, Hi-Joon;Hahm, Dae-Hyun;Lee, Hye-Jung
    • Korean Journal of Acupuncture
    • /
    • v.29 no.1
    • /
    • pp.47-55
    • /
    • 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.

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

  • Kwon, Dong-hyun;Heo, Sung-uk;Lim, Ji-yong;Oh, Am-suk;Kim, Wan-sik
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2016.10a
    • /
    • pp.142-144
    • /
    • 2016
  • Recent promising technologies of the manufacturing sector interest, and the interest in 3D printing that is expected to cause a huge ripple effect rapidly, and various types of products advertised in accordance with the falling price of 3D printers is spreading. However, the personal 3D printers that are currently being advertised is used for Injection output of the simple type that does not require a high processing precision in accordance with the limitation of technical performance, and consumer satisfaction is very low. In this paper, we propose a 3D printer, 3D precision to overcome existing limitations in the way the printer's high SLA 3D printer that combines injection method and the LSU (Laser Scanning Unit) in the office laser printer polygon mirror scanning method. 3D printers which are proposed to improve the accuracy and manufacturing speed is expected to replace the existing entry-level 3D printer.

  • PDF