• 제목/요약/키워드: 김대식

검색결과 839건 처리시간 0.037초

긴물푸레나무 근피(根皮)의 Coumarin성분(成分) 연구(硏究)(IV) (Coumarin Glycosides of Fraxinus japonica Blume forma intermedia Hara)

  • 육창수;김대식;김성만
    • 약학회지
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    • 제28권5호
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    • pp.283-286
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    • 1984
  • Fraxinus japonica Blume forma intermedia Hara, belonging to Oleacae Family, is growing in Korea. The identification of the species with the root bark extract is possible through the TLC method, and is more distinctive than through the PPC. The methanolextract of the root bark of Fraxinus japonica Blume forma intermedia Hara gave two coumarin glycosides, (fraxin $C_{16}M_{18}O_{10}$ and aesculin $C_{15}H_{16}O_9$) and mannitol.

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RFID 응용 사례 연구 : 비즈니스 모델 관점 (Case Study for RFID Applications from Business Model Perspective)

  • 정석인;김대식
    • Journal of Information Technology Applications and Management
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    • 제20권1호
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    • pp.197-216
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    • 2013
  • Despite the vast potential opportunities of RFID technology in various industrial applications, deployment of RFID applications is rather limited to meet a large industrial demand in Korea. We conducted in-depth case study to organize the RFID applications in business model framework in order to provide practical insights for the development of innovative RFID applications. Throughout extensive searching for RFID applications in literature, web, news, and policy reports, we first classified passive RFID applications, mobile RFID applications, and active RFID applications. Value creation and implementation issues are compared and analyzed for each of RFID applications using Afuah and Tucci business model. This study can contribute in establishing future development of RFID technology, competitive business strategy, and government policy to stimulate Korea RFID industry.

KEM-SPEC. 운영시스템 개발 (Development of Operation System for KEM-SPEC)

  • 안준호;왕용필;박민영;장영길;서순석;김광곤;김대식;한상옥
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2009년도 춘계학술대회 논문집 전기설비전문위원
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    • pp.365-367
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    • 2009
  • 본 논문에서는 전기공사 단위시방서 작성 및 운영에 필요한 KEM-SPEC. 운영시스템을 개발하였다. KEM-SPEC. 운용시스템은 전기설비 시공에 있어, 필요한 공사시방서 작성 시, 누락과 오류, 중복적 피해를 최소화 하고, 전기공사 시공품질과 성능을 확보할 수 있다.

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희박 예혼합 연소기에서 연료 조성이 화염전달함수 특성에 미치는 영향 (Effects of Fuel Composition on Flame Transfer Function in Lean Premixed Combustor)

  • 김진아;김지환;이정원;김대식
    • 한국분무공학회지
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    • 제20권3호
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    • pp.135-140
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    • 2015
  • Flame transfer function is used to determine the relationship between flow fluctuations and heat release perturbations in a lean premixed gas turbine combustor. The characteristics of flame transfer function are known to depend greatly on flame geometries in addition to other various flow conditions. However, it is not easy to experimentally measure the flame transfer function under various actual combustor operating conditions in terms of time and cost. The current research tries to model the flame transfer function using CFD(Computational Fluid Dynamics). From the results, it is shown that the calculated steady flame geometry can be exactly captured with consideration of the wall heat transfer and radiations. Also, unsteady analysis results show the close characteristics of the flame transfer function to the measured one in both gain and phase.

엘리베이터용 헬리컬기어의 전달오차 해석 (Transmission Error Analysis of the Helical Gears for the Elevator)

  • 박찬일;김대식
    • 대한기계학회논문집A
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    • 제26권12호
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    • pp.2695-2702
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    • 2002
  • The elevator gear box with the helical gears needs to be developed instead of the one with the worm gears to improve the efficiency. In order to develop the gear box, the analytical tool to predict the helical gear noise is necessary to meet customer's noise requirement. Gear noise is related to the loaded transmission error. Therefore, the simulation program fer the loaded transmission error analysis of the helical gears is developed in this study. Using the developed program, the effects of tooth modification such as tip relief and the extent of tip relief are investigated. Finally, the procedures to determine the tip relief and the extent of tip relief are proposed.

광 정보 저장 장치에서의 비구면 렌즈 가공 기술 (Aspherical Lens Manufacturing Technology in the Optical Storage Device)

  • 이호철;김대식;이철우;김부태;양민양
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2001년도 춘계학술대회 논문집
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    • pp.964-967
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    • 2001
  • Aspherical lens with the higher numerical aperture has been needed in the optical storage device to increase the recording density on the disk. However, high numerical aperture means the large slope angle at the clear aperture of the lens. Therefore, the measurement and manufacturing technique including the lens molding process for the slope angle should be developed. In this paper, the evaluation technique was described for the optical performance of the aspherical lens. Aspherical form error brings about the wavefront error and the side lobe of the beam intensity profile. A schematic diagram of the aspherical lens manufacturing was drawn to explain the aspherical form error compensation. Finally, form error of the aspherical lens was defined and plotted using the raw data of the Formtalysurf.

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LonRF 지능형 디바이스 기반의 유비쿼터스 홈네트워크 테스트베드 개발 (Development of a LonRF Intelligent Device-based Ubiquitous Home Network Testbed)

  • 이병복;박애순;김대식;노광현
    • 제어로봇시스템학회논문지
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    • 제10권6호
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    • pp.566-573
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    • 2004
  • This paper describes the ubiquitous home network (uHome-net) testbed and LonRF intelligent devices based on LonWorks technology. These devices consist of Neuron Chip, RF transceiver, sensor, and other peripheral components. Using LonRF devices, a home control network can be simplified and most devices can be operated on LonWorks control network. Also, Indoor Positioning System (IPS) that can serve various location based services was implemented in uHome-net. Smart Badge of IPS, that is a special LonRF device, can measure the 3D location of objects in the indoor environment. In the uHome-net testbed, remote control service, cooking help service, wireless remote metering service, baby monitoring service and security & fire prevention service were realized. This research shows the vision of the ubiquitous home network that will be emerged in the near future.

KTX 안전운행 확보를 위한 ATP시스템 설치 최적화 방안 (A study on the optimum ATP installation for KTX safety running)

  • 유병관;김대식
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2007년도 춘계학술대회 논문집
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    • pp.1388-1397
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    • 2007
  • In order to install ATP system for KTX safety running, a study has been done to examine measures to ensure the interface between KTX and ATP system. Although onboard signaling system is efficient and has been verified both at home and abroad, alternatives for optimum installation shall be adopted so as to show designated performance taking into account the given peripheral device. A solution to interface between beacon and onboard system shall be presented especially for the KTX, which runs on both high speed and conventional line (ATP-ATS). Furthermore, the method for controlling the braking process and recorder shall be studied.

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GaAs 양자우물에서 흡수와 편광소멸의 결맞는 조절 : 시간과 에너지 영역 연구 (Coherent Control of Absorption and Polarization Decay in GaAs Quantum Wells : Time and Spectral Domain Studies)

  • 김대식;이대수;이기주;홍성철
    • 한국광학회:학술대회논문집
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    • 한국광학회 2000년도 제11회 정기총회 및 00년 동계학술발표회 논문집
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    • pp.18-19
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    • 2000
  • Recently, coherent control of exciton populations has been demonstrated through terahertz, reflection, and four-wave-mixing experiments. However, the most direct probe of exciton population control is the absorption, which has been lacking in previous studies. In this report, we probe the time evolution of exciton population directly through a transmission experiment. In particular, using upconversion technique with both narrow (spectrally broad) and long (spectrally narrow) pulses, we can obtain both the temporal and the spectral information. The main thrust of our report is that when phase controlled, the second pulse can be either greatly enhanced or completely destroyed by gaining energy from exciton (thus destroying the exciton population) or giving all of its energy to the system (thus greatly increasing the exciton population), respectively. (omitted)

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신재생에너지전원(태양광, 풍력)의 저압배전계통연계 자동평가시스템 개발 (Development of Automatic Evaluation System for Interconnection of Renewable Power Sources in Distribution Systems)

  • 노대석;김효진;김대식;원성호
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2008년도 제39회 하계학술대회
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    • pp.2069-1-2070-1
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    • 2008
  • 산업자원부에서는 국가에너지사업의 정책으로 지역 에너지사업 및 신 재생에너지 시범보급사업을 수행하고 있으며, 이에 따라 대규모 신재생에너지전원(태양광, 풍력, 열병합 등) 단지가 활발하게 조성되고 있는 상황이다. 그러나 신재생에너지전원의 설치자 측에서는 설비비용의 절감을 이유로 일반배전선로(고압 및 저압배전선로)에 직접적인 연계를 요구하고 있으나, 한전 측에서는 계통운용의 어려움으로 인하여 까다로운 계통연계지침(가이드라인)을 정하여, 한전 측과 전기사업자(전기공사업자 및 발전 사업업자)간의 이해가 상충되는 부분이 발생하고 있는 실정이다. 따라서 본 연구에서는 신재생에너지전원의 발전업자와 전기공사업자의 측면에서는 효율적인 공사 및 시공을 위하여, 배전계통 연계와 관련된 복잡한 기술적인 계통연계 지침을 일일이 해석하지 않더라도, 연계 적합여부를 손쉽고 자동적으로 판단해주는 평가시스템을 개발하였다.

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