• 제목/요약/키워드: a optic fiber

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A Understanding of the Temporal Stem

  • Choi, Chan-Young;Han, Seong-Rok;Yee, Gi-Taek;Lee, Chae-Heuck
    • Journal of Korean Neurosurgical Society
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    • 제47권5호
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    • pp.365-369
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    • 2010
  • Objective : There has been inconsistency about definition of the temporal stem despite of several descriptions demonstrating its microanatomy using fiber dissection and/or diffusion tensor tractography. This study was designed to clarify three dimensional configurations of the temporal stem. Methods : The fronto-temporal regions of several formalin-fixed human cerebral hemispheres were dissected under an operating microscope using the fiber dissection technique. The consecutive coronal cuts of the dissected specimens were made to define the relationships of white matter tracts comprising the temporal stem and the subcortical gray matters (thalamus, caudate nucleus, amygdala) with inferior limiting (circular) sulcus of insula. Results : The inferior limiting sulcus of insula, limen insulae, medial sylvian groove, and caudate nucleus/amygdala were more appropriate anatomical structures than the roof/dorso-lateral wall of the temporal horn and lateral geniculate body which were used to describe previously for delineating the temporal stem. The particular space located inside the line connecting the inferior limiting sulcus of insula, limen insulae, medial sylvian groove/amygdala, and tail of caudate nucleus could be documented. This space included the extreme capsule, uncinate fasciculus, inferior occipito-frontal fasciculus, anterior commissure, ansa peduncularis, and inferior thalamic peduncle including optic radiations, whereas the stria terminalis, cingulum, fimbria, and inferior longitudinal fiber of the temporal lobe were not passing through this space. Also, this continued posteriorly along the caudate nucleus and limiting sulcus of the insula. Conclusion : The temporal stem is white matter fibers passing through a particular space of the temporal lobe located inside the line connecting the inferior limiting sulcus of insula, limen insulae, medial sylvian groove/amygdala, and tail of caudate nucleus. The three dimensional configurations of the temporal stem are expected to give the very useful anatomical and surgical insights in the temporal lobe.

측광 후처리 가공에 의한 유연 광직물의 발광 효과 (Luminescence effects of POF-based Flexible Textile by post-treated Optic illuminate)

  • 양은경;이주현
    • 감성과학
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    • 제14권4호
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    • pp.495-502
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    • 2011
  • 광섬유 직물 기반 스마트 의류가 국, 내외로 개발되고 있는 실정이며, 기존의 일반적인 광섬유는 직물화가 어렵고 내구성, 내수성이 결여되어 세탁 및 유지 관리의 한계로 인해 에칭된 광섬유사의 표면에 합성수지를 코팅 처리하는 '내수성 광섬유사 가공 기술'이 최근 개발 되었다. 본 연구에서는 제직 후 측광가공 된 유연 광섬유 직물을 대상으로 광섬유사 길이에 따른 특성과 광원 색채에 따른 발광 특성을 분석, 평가하여 디지털 컬러 의류의 적용 적합성을 파악하고자 한다. 이를 위하여 광섬유사 길이에 따른 총 4가지 유연 광섬유 직물시료를 제직하여, 이를 대상으로 광원 색채에 따른 유연 광섬유 직물의 휘도, 물리적 가시도, 지각적 가시도를 측정함으로써 발광특성을 분석하였다. 그 결과, 10cm인 유연 광섬유 직물과 녹색 광원을 사용한 경우가 최대가시거리 100m로 디지털 컬러 의류 즉, 안전보호 기능의 산악복 적용에 가장 적합한 발광효과를 보이는 것으로 나타났다. 그러므로 본 연구의 결과는 앞으로 유연 광섬유 직물 적용 의류 개발과 관련된 후속 연구의 자료로서 활용될 수 있을 것으로 기대된다.

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LC(Liquid crystal)-광섬유를 이용한 최소 침습적 레이저 온열 치료용 온도 측정 센서의 개발을 위한 기초 연구 (Feasibility study on the development of Liquid crystal-optical fiber temperature sensor for minimal invasive laserthermia)

  • 이봉수;황영묵;정순철
    • 센서학회지
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    • 제12권5호
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    • pp.225-230
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    • 2003
  • 최근 최소 침습적 수술(minimal invasive surgery)방법에 대한 관심이 높아지면서 인체 내부의 악성 종양을 치료하는 방법 중의 하나로 레이저를 이용한 온열 치료법(laserthermia)이 사용되고 있다. 인체 심부의 암세포에 대한 레이저 열 치료는 레이저를 조직에 흡수시키면서 발생되는 열을 이용하여 암세포를 제거하는 방법이다. 본 시스템은 레이저 전달용 광섬유, 영상 획득용 내시경, 온도 측정 센서 등으로 구성된다. 온열 요법은 치료할 암세포를 적절한 온도($42{\sim}43^{\circ}C$)로 유지시켜주면서 정상 세포는 레이저의 조사에 의한 열 발생을 최소화시키는 것이 중요한데 이러한 온도 유지를 위해서는 신속 정착한 온도 측정이 요구되고 있다. 본 연구에서는 새로운 형태의 LC(liquid crystal)-광섬유 온도 측정 센서를 개발하기 위해 온도 변화에 따른 LC물질의 색 변화 정도를 수광-발광 광섬유로서 측정하였고 측정된 수광량과 온도 변화 사이의 관계식을 도출하였다. 그리고 광섬유와 LC물질간의 복잡한 거리 문제를 해결하고, 보다 향상된 실험 결과를 얻기 위해 Y-coupler를 제작하여 LC물질의 반사 광량과 온도 사이의 관계도 알아보았다.

실리카 졸-겔막을 이용한 pH 광학센서 (A pH Optosensor Based on Fluoresence from Nile Blue Encapsulated within Silica Sol-Gel Film)

  • 이정민;이명;이상학;김영선;김창진;이부형
    • 센서학회지
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    • 제13권3호
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    • pp.169-174
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    • 2004
  • A fiber optic pH sensor has been fabricated using nile blue entrapped in an ammonia catalyzed silica sol-gel film coated on glass substrate by dip-coating. The sensor was fixed on the end of an optical fiber. The sensor showed pH sensitivity when dipped into liquids at different pHs. Linear and reproducible responses were obtained in standard buffer solutions in the pH range $6.0{\sim}8.5$, which encompasses the clinically-relevant range. The effects of interferences on the determination of pH were also investigated. The sensors were successfully applied to the determination of pH in different commercial ionic drinks.

도로교 안전관리 모니터링 시스템의 입력하중 측정을 위한 FBG 기반 하중 측정시스템 개발에 관한 연구 (A Study on the Development of FBG-Based Load Measurement System for Structural Health Monitoring of Highway Bridge)

  • 이규완;한종욱;김철영;박영석
    • 대한토목학회논문집
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    • 제39권4호
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    • pp.469-475
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    • 2019
  • 구조물의 장기적인 안전관리를 위하여 교량 장기계측시스템이 도입되어 운영 중에 있다. 그러나 일반적인 교량 장기계측시스템은 응답만 측정하고 입력하중은 측정하지 못하고 있기 때문에, 추세분석에 의한 관리기준 상회여부만을 판단하고 있어 정량적인 구조계의 상태평가가 어려운 실정이다. 이러한 단점을 극복하기 위하여 본 논문에서는 도로교 입력하중 측정을 위한 FBG 기반 입력하중 측정센서를 개발하였으며, 실내실험을 통하여 그 타당성을 검증하였다.

CW Nd:YAG Laser를 이용한 SM45C 환봉의 표면 열처리 특성 (The characteristics of Surface Transformation Hardening for Rod-shaped SM45C Carbon Steel by CW Nd:YAG Laser)

  • 김종도;강운주;이창제;이제훈;서정;이문용
    • 대한용접접합학회:학술대회논문집
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    • 대한용접접합학회 2006년도 춘계 학술대회 개요집
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    • pp.248-250
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    • 2006
  • The study on a surface transformation hardening of a rod-shaped SM45C carbon steel is carried out by using CW Nd:YAG laser. Conventionally, $CO_2$ laser has been usually used as a laser source for a transformation hardening. however, it is needed to an additional absorbent coating like a colloidal graphite owing to a lower absorbtion rate. On the other hand, no cost and post-removal process of coating is required to Nd:YAG laser, due to a higher absorbtion rate relatively. Moreover, there is a merit which is capable of building up the more flexible processing system resulted from a beam delivery through a optical fiber. In this study, we were going to recognize characteristics of a transformation hardening using a optic head with a gaussian beam distribution.

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보울 피이더에서 신경 회로망을 이용한 부품 자세 인식에 관한 연구 (A neural network method for recognition of part orientation in a bowl feeder)

  • 임태균;김종형;조형석;김성권
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.275-280
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    • 1990
  • A neural network method is applied for recognizing the orientation o f individual parts being fed from a bowl feeder. The system is designed in such a way that a part can be discriminated and sorting according to every possible stable orientation without implementing any a mechanical tooling. The operation of the bowl feeder is based on a 2D image obtained from an array of fiber optic sensor located on the feeder track. The acquired binary image of a moving and vibrating part is used as input to a neural network which, in turn, determines t he orientation of the part. The main task of the neural network, here is to synthesize the appropriate internal discriminant functions for the part orientation using the part features. A series of the experiments reveals several promising points on performance. Since the operation of the feeder is highly programmable, it is well suited for feeding and sorting small parts prior to small batch assembly work.

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Structural Characteristic Analysis of a High-precision Centerless Grinding Machine with a Concrete-filled Bed

  • Kim, Seok-Il;Cho, Jae-Wan
    • International Journal of Precision Engineering and Manufacturing
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    • 제7권4호
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    • pp.34-39
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    • 2006
  • High-precision centerless grinding machines are emerging as a means of finishing the outer diameter grinding process required for ferrules, which are widely used as fiber optic connectors. In this study, a structural characteristic analysis and evaluation were carried out using a virtual prototype of a centerless grinding machine to realize systematic design technology and performance improvements required to manufacture ferrules. The prototype consisted of a concrete-filled bed, hydrostatic grinding wheel (GW) and regulating wheel (RW) spindle systems, a hydrostatic RW feed mechanism, a RW swivel mechanism, and on-machine GW and RW dressers. The loop stiffness values of the centerless grinding machine were estimated based on the relative displacements between the GW and RW caused by grinding forces. The simulated results illustrated that a concrete-filled bed considerably improved the structural stiffness and accuracy of a high-precision centerless grinding machine.

Airway management in a displaced comminuted fracture of the mandible and atlas with a vertebral artery injury: A case report

  • Paramaswamy, Rathna
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제18권3호
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    • pp.183-187
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    • 2018
  • Complex cervical spine fractures are a serious complications of maxillofacial trauma and associated with high mortality and neurological morbidity. Strict vigilance in preventing further insult to the cervical spine is a crucial step in managing patients who are at risk for neurologic compromise. We report a rare case of a right transverse process of atlas fracture with right-sided vertebral artery injury that was associated with a comminuted fracture of the body and angle of the mandible, which restricted mouth opening. Airway management was performed by an awake fiber-optic nasotracheal intubation, where neck movement was avoided with a cervical collar. Vertebral artery injuries may have disastrous consequences, such as basilar territory infarction and death, and should be suspected in patients with head and neck trauma. After mandibular plating, the patient was on cervical collar immobilization for 12 weeks and anti-coagulant therapy.

Option of EDFAs for WDM Long-Haul Transmission Systems Gain Flattening With or Without a Gain Equalizer

  • Chung, Hee-Sang;Choi, Hyun-Beom;Lee, Mun-Seob;Lee, Dong-Han;Ahn, Seong-Joon;Choi, Bong-Su;Moon, Hyung-Myung;Lee, Kyu-Haeng
    • Journal of the Optical Society of Korea
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    • 제4권1호
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    • pp.14-18
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    • 2000
  • We have investigated gain flattening of EDFA systems with or without a gain equalizer for WDM long-haul transmission using a re-circulating EDFA loop. Without a gain equalizer, gain variation as small as 2.9 dB was achieved over the 10-nm band of a 100 cascaded EDFA system by the inversion principle. With a gain equalizer based on all-fiber acousto-optic tunable filters, two different config-urations of EDFAs were tested. For a single-stage EDFA scheme, the 21-nm band has shown 3.8 dB of gain variation at 17.4 ∼ 20.3 dB of OSNRs after the 100the stage of EDFAs. For a dual-stage EDFA scheme, a wider bandwidth of 34 nm has shown 3.6-dB variation after 40 cascaded EDFAs.