• 제목/요약/키워드: Fiber-optic

검색결과 1,082건 처리시간 0.029초

네트워크 GR형 수신기와 컨트롤데스크를 이용한 통합방재관리시스템에 대한 연구 (The Study on the Integrated Emergency Management System using Network GR-type Receiver and Control Desk)

  • 백동현;송호빈;강원선
    • 한국화재소방학회논문지
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    • 제26권1호
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    • pp.96-101
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    • 2012
  • 근래의 건축물들은 고층화와 지하 심층화되고 있어 화재 발생 시 대형 사고의 가능성이 매우 높으므로 여러 장소에 개별적으로 설치되어 있는 화재수신기의 방재정보를 통합하여 관리할 필요가 있다. 본 논문에서는 각각 떨어진 장소에 설치된 화재수신기에 대해 원격으로 감시 및 제어 가능하며 인터넷과 광케이블로 연결 할 수 있는 네트워크형 화재수신기와 컨트롤데스크를 제작한 다음 각 장치 간에 화재발생 및 이상상태를 감시하고 상황에 따라 모니터링, 경보, 제어 및 유지관리를 수행 할 수 있는 통합관리시스템을 개발하였다. 제안한 시스템을 국가검정기준에 의하여 평가하고, 각 구간의 신호 전달 시간에 대해 실험을 수행하여 성능의 안정성을 확인하였다.

Picture archiving and communications systems development and performance results

  • Nam, Ji-Seung;Ralph Martinez
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1991년도 한국자동제어학술회의논문집(국제학술편); KOEX, Seoul; 22-24 Oct. 1991
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    • pp.1796-1800
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    • 1991
  • Picture Archiving and Communication Systems(PACS) provide an integration of digital imaging information in a hospital, which encompasses various imaging equipment, viewing workstations, database archive systems, and a high speed fiber optic network. One of the most important requirements for integration is the standardization of communication protocols to connect devices from different vendors. Since 1985, the ACR-NEMA standard provides a hardware interface, a set of software commands, and a consistent set of data formats for point-to-point interconnection of medical equipment. However, it has been shown to be inadequate for PACS networking environments, because of its point-to-point nature and its inflexibility to allow other services and protocols in the future. Based on previous experience of PACS developments in The University of Arizona, a new communication protocol for PACS networks has been suggested to the ACR-NEMA Working Group VI. The defined PACS protocol is intended to facilitate the development of PACS's capable of interfacing with other hospital information systems. Also, it is intended to allow the creation of diagnostic information data bases which can be interrogated by a variety of distributed devices. A particularly important goal is to support communications in a multivendor environment. The new protocol specifications are defined primarily as a combination of the International Organization for Standardization / Open Systems Interconnection (ISO/OSI) protocols and the data format portion of ACR-NEMA standard. This paper addresses the specification and implementation of the proposed PACS protocol into network node. The protocol specification, which covers Presentation, Session, Transport, and Network layers, is summarized briefly. The implementation has natural extentions to Global PACS environments. The protocol implementation is discussed based on our implementation efforts in the UNIX Operating System Environment. At the same time, results of performance evaluation are presented to demonstrate the implementation of defined protocol. The testing of performance analysis is performed on the PACS prototype node.

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VLBI 전파망원경 기준 신호 전송시스템 안정화 (STABILIZATION OF REFERENCE SIGNAL TRANSMISSION SYSTEM IN RADIO TELESCOPE FOR VLBI)

  • 제도흥;이원규;김수연;정문희;송민규;정태현;변도영;김승래;손봉원;위석오;한석태;강용우
    • 천문학논총
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    • 제28권3호
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    • pp.95-100
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    • 2013
  • A fiber-optic reference signal transmission system, which transmits the 1.4 GHz reference signal from H-maser to receiver cabin in radio telescopes, was adopted for compensating the phase changes due to temperature variation and antenna movement. At the first experiment, the remote signal's phase changed more than 15 degrees at 1.4 GHz. We found unstable components in sub-system experiments and replaced them. The main cause of unstable phase stability was the unaligned polarization axis between Laser Diode and Mach-Zehnder Modulator (MZM). The improved system stability showed $1{\times}10^{-16}$ allan standard deviation at 1,000 sec integration time with the antenna fixed. When the antenna moves in the azimuth axis, the 1.4 GHz remote signal showed the phase change smaller than 0.2 degrees.

생체분자막을 이용한 생물분자소자의 개발 제1부 :효소분자 LB막을 이용한 에탄올 측정용 광학 바이오센서 (Development of Biomolecular Device Using Biomolecular Film Part 1: Optical Biosensor to Detect the Ethanol Using Langmuir-Blodgett Film of Eilzyme Molecules)

  • 최정우;배주연지용이원홍
    • KSBB Journal
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    • 제10권1호
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    • pp.105-112
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    • 1995
  • 본 연구에서는 LB기법에 의하여 분자수준으로 고 정화된 효소를 이용하여 에탄올의 양을 측정하는 광섬유 바이오센서가 개발되 었다. ADH는 arachidic acid의 단분자막에 LB기법으로 고정화된다. 센서의 출력신호를 분석하기 위하여 고정화된 ADH의 효소 반응은 ordered multisubstrate mechanism을 이용 하여 검토되었다. 광학 측정 시스템이 제시되었으며, 센서의 출력신호는 에단올의 농도에 비례하여 증가 하며 LB막에 누적된 누적충수와 관련이 있음을 알 수 있었다. LB막의 누적된 누적충수를 20충으로 증가하면 센서의 신호출력 범위가 확장되어 45mM의 고농도 에탄올도 측정할 수 있었다. 순수지질의 단 분자막과 효소가 흡착된 지질의 단분자막의 $\pi$-Aisotherm은 중성의 subphase에서 각기 다른 전하를 띠는 세 가지 종류의 지질에 대하여 조사되었다. ADH의 흡착도가 가장 우수한 지질은 arachidic a acid이며 이는 중성의 sub phase에서 양의 전하를 띠는 ADH 분자와 읍극의 전하를 띠는 arachidic a acid 분자 사이에 작용하는 정전기력에 기인한 것이다.

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다축 수준기의 오차분석을 통한 측정 정밀도 향상 (Development of accuracy for the statical inclinometer by error analysis)

  • 이정근;박재준;조남규
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 춘계학술대회 논문집
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    • pp.1797-1802
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    • 2005
  • In this study, we were developed an accuracy of the proposed two dimensional statical inclinometer what used a position sensitive detector(PSD) by an error analysis. The inclinometer consists of a laser source, a mass, an optic-fiber, and a PSD. The gravity direction on a base platform of the inclinometer is changed by an unknown inclination angle. And a laser spot is moved from the origin to another position of a PSD following a variation of an optical path by the gravity. These processes enable the inclinometer to estimate the inclination angle from distance information of the moving spot. A design methodology on the basis of a sensitivity analysis was applied to improve the measurement performance such as a full measuring range and a resolution. But it still has error factors, so we analyze the uncertainty of the inclinometer to evaluate the systematic errors from alignments, assembly error and so on. The experimental performance evaluation about the design objectives as a measuring range and a resolution was performed. And the validity and the feasibility of the design process were certified by an experimental process. Systematic errors eliminated to improve the accuracy of the inclinometer by the corrected measuring model from the calibration process between the inclination angle and the PSD position instead of the nominal measuring model. The ANOVA(analysis of variance) confirmed the effect of eliminating the systematic errors in the inclinometer. From these methodologies, the proposed inclinometer was able to measure with a high resolution(35.14sec) and a wide range(from $-15^{\circ}\;to\;15^{\circ}$

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QUICK DETERMINATION OF MEAT COLOR, METMYOGLOBIN FORMATION AND LIPID OXIDATION IN BEEF, PORK AND CHICKEN BY NEAR-INFRARED SPECTROSCOPY

  • Mitsumoto, Mitsuru;Sasaki, Keisuke;Murakami, Hitoshi
    • 한국근적외분광분석학회:학술대회논문집
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    • 한국근적외분광분석학회 2001년도 NIR-2001
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    • pp.1259-1259
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    • 2001
  • Meat becomes brown and rancid during storage in the refrigerator and display in the case. Color changes, metmyoglobin formation and lipid oxidation are the important problems in the transportation / distribution of meat and retail display. The freshness of meat is determined by the sense of vision and smell. Since conventional method determining lipid oxidation is time consuming and destructive (it needs to homogenize meat with reagents, filtrate, time for reaction and read optical density using spectroscopy), more rapid and nondestructive technical tools are desired. The objective of this work was to evaluate near-infrared spectroscopy as an analytical tool for determining meat color, metmyoglobin formation and lipid oxidation. in beef, pork and chicken. Semitendinosus and longissimus thoracis muscles from six beef steers, biceps femoris and longissimus thoracis muscles from twelve LWD crossbred pigs, and superficial pectoral muscles from twenty-four broilers were used. About a 5-cm diameter and 1-cm thick sample (20.0g) was cut from the muscle and placed on plastic foam, over-wrapped with PVC film, and displayed under flourescent lights at 4 degrees C. during 10 days for beef and pork or 4 days for chicken. The spectra was measured by NIR systems Model 5500 Spectrophotometer using fiber optic scan at range of 400 - 1100 nm. Data were recorded at 2 nm intervals and 10 scans / 10 sec were averaged for every sample. Data obtained were saved as log 1/Re, where Re is the reflectance energy, and then mathematically transformed to second derivatives to reduce effects of differences in particle size. $L^{*}$, $a^{*}$ and $b^{*}$, and metmyoglobin formation were determined by conventional spectrophotometer using the integrating sphere unit. 2-Thiobarbituric acid reactive substances (TBARS) were measured for lipid oxidation. A multiple linear regression was used to find the equation which would best fit the data. The number of wavelengths used in the equation was selected based on the fewer number compared to the increasing multiple correlation and Decreasing standard error. (omitted)

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복합재료 파손 검출을 위한 EFPI 센서 위상 안정화 시스템 (A Phase Stabilization System of EFPI for Damage Detection of Composite)

  • 김대현;구본용;방형준;김천곤;홍창선
    • 한국항공우주학회지
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    • 제31권8호
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    • pp.44-49
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    • 2003
  • EFPI (extrinsic Fabry-Perot interferometer) 센서를 이용해 복합재료의 파손 신호를 취득하기 위해서는 파손 신호에 비해 상대적으로 낮은 주파수의 열적, 기계적 준정적 변형에 의해 발생하는 위상 변화를 보상해 주는 기술이 필요하다. 또한 센서의 민감도를 최적화하기 위해 출력 신호의 위상을 쿼드러쳐 (quadrature) 지점에 유지시켜야 한다. 본 논문에서는 EFPI 센서 시스템의 출력 신호 위상을 일정하게 유지시킬 수 있는 안정화 제어 시스템을 개발하였다. 안정화 제어 시스템은 광대역 파장 레이저 광원, 가변 F-P (Fabry-Perot) 필터 그리고 필터를 제어할 수 있는 전자 회로 시스템으로 구성하였다. 개발된 시스템의 위상 제어 성능을 평가하기 위해 복합재료 시편의 인장 실험을 수행하여 인장 변형에 의해 발생하는 위상 변화를 개발된 시스템을 이용해 쿼드러쳐 지점에 일정하게 유지할 수 있음을 보였다.

유류 오염 토양에서의 단일방향족 탄화수소 농도 측정을 위한 자외선 형광 분석에 관한 연구 (Detection of fluorescence from soils contaminated with monoaromatic hydrocarbons)

  • 김우진;박재우;이주인
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제7권2호
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    • pp.35-44
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    • 2002
  • 유류로 오염될 위험성이 있는 지역에서 유류의 누출을 미리 감지하여 오염의 확산을 막기 위한 시스템을 개발하기 위하여, 유류에 상당량이 함유되어 있는 벤젠, 톨루엔, 에틸벤젠, 자일렌의 농도별 형광세기를 측정하였다. 이것은 단일방향족 탄화수소계 물질이 260nm대의 자외선영역의 빛을 흡수하여 290nm 파장 영역의 형광을 낸다는 원리를 이용한 것이었으나 실제 토양 시료의 형광을 측정할 때는 300-600nm파장 영역에서 형광이 나왔다 이것은 토양이 입자 물질로 구성되어 있기 때문에 나타나는 경향이라 사료된다. 흡광 영역이 비슷한 이 네 가지 단일 방향족 탄화수소계 물질들은 그 형광을 내는 파장 영역도 비슷하였으며, 토양시료의 형광세기는 오염시킨 농도가 증가함에 따라 증가하였다. 또한 이러한 경향은 토양 입자가 미세한 토양에서 더 뚜렷하게 나타났다. 따라서 본 측정 기술은 기존의 방법에 비하여 신뢰도가 높은 데이터를 얻을 수 있고, 간편하고 단순하여 한번의 설치로 주기적인 측정이 가능하므로 유류 오염의 위험이 있는 지역에서의 상시 측정장치로서 효과적일 것으로 판단된다.

정상견 무릎의 관절경 검사소견 (Arthroscopic Findings of the Canine Stifle Joint)

  • 정순욱;정월순
    • 한국임상수의학회지
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    • 제16권2호
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    • pp.300-308
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    • 1999
  • Arthroscopy is a valuable diagnostic and operative tool in equine and human orthopedics. The arthroscope is a difficult instrument to use and requires patience, practice, and persistence in order to obtain good results. This technique was found to be less traumatic than arthrotomy, invasiveness, rapid recovery and the feasibility of surgically correcting many arthropathies. The use of the arthroscope in the dog provides a new dimension in the study and diagnosis of joint derangements. The purpose of this report is to introduce the use of the arthroscope in the dog-more specifically, in the stifle of the dog. A diameter 2.7 mm fore-oblique viewing arthroscope, cold light source, video and video printer are used. With the fore-oblique viewing type it is possible to view directly as well as slightly to the side and the range of viewing can be increased by rotating the arthroscope around the object The scope is connected with a cold light source by means of a fiber-optic light guide. The stifle joint was flexed to 20~30$^{\circ}$. The joint were lavaged with lactated Ringer's solution during arthroscopic examination. Arthroscopy of the stifle was performed prior to arthrotomy in 1 dead dog and 4 healthy dogs, and other 3 dogs was performed only arthroscopic examination. In this study only the conventional approaches were used and in most cases it was possible to view all the intra-articular structures via the lateral infrapatellar approach. In the stifle joint, endoscopic observation was performed to find lateral femoral condyle, patella, medial femoral condyle, trochlear groove, tibia, fat, cranial cruciate ligament, caudal cruciate ligament lateral meniscus, tendon of long digital extensor muscle, medial meniscus, and medial collateral ligament Post-arthroscopic examination, the lameness had disappeared within 12~24 hours. Pain and swelling in the stifle joint had disappeared within 24~36 hours. Post-arthroscopic secondary infection was never encountered in the dogs. In conclusion, arthroscopic insertion technique in canine stifle joint using a diameter 2.7 mm 30$^{\circ}$ arthroscope was established and arthroscopical views of all anatomical structures in the normal stilfe joint were obtained through lateral infrapatellar portal.

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원전 안전통신망을 위한 TDMA 기반의 프로토콜 개발 (Development of TDMA-Based Protocol for Safety Networks in Nuclear Power Plants)

  • 김동훈;박성우;김정헌
    • 대한전기학회논문지:시스템및제어부문D
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    • 제55권7호
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    • pp.303-312
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    • 2006
  • This paper proposes the architecture and protocol of a data communication network for the safety system in nuclear power plants. First, we establish four design criteria with respect to determinability, reliability, separation and isolation, and verification/validation. Next we construct the architecture of the safety network for the following systems: PPS (Plant Protection System), ESF-CCS (Engineered Safety Features-Component Control System) and CPCS (Core Protection Calculator System). The safety network consists of 12 sub-networks and takes the form of a hierarchical star. Among 163 communication nodes are about 1600 origin-destination (OD) pairs created on their traffic demands. The OD pairs are allowed to exchange data only during the pre-assigned time slots. Finally, the communication protocol is designed in consideration of design factors for the safety network. The design factors include a network topology of star, fiber-optic transmission media, synchronous data transfer mode, point-to-point link configuration, and a periodic transmission schedule etc. The resulting protocol is the modification of IEEE 802.15.4 (LR-WPAN) MAC combined with IEEE 802.3 (Fast Ethernet) PHY. The MAC layer of IEEE 802.15.4 is simplified by eliminating some unnecessary (unctions. Most importantly, the optional TDMA-like scheme called the guaranteed time slot (GTS) is changed to be mandatory to guarantee the periodic data transfer. The proposed protocol is formally specified using the SDL. By performing simulations and validations using Telelogic Tau SDL Suite, we find that the proposed safety protocol fits well with the characteristics and the requirements of the safety system in nuclear power plants.