• 제목/요약/키워드: Reference Point

검색결과 1,781건 처리시간 0.031초

위치정보 제공 서비스를 위한 유비쿼터스 기준점 설계 연구 (Design of Ubiquitous Reference Point for Location Service)

  • 박재민;오윤석;강진아;김병국
    • Spatial Information Research
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    • 제15권3호
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    • pp.301-310
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    • 2007
  • 현재 우리나라에는 전국에 약 21,000점의 측량용 국가기준점이 표석 형태로 매설되어 있으며, 대부분이 시통을 위해 산 정상에 매설되어 있어 일반인들의 사용과 접근이 어렵다. 최근 유비쿼터스 환경이 구축되어 감에 따라 위치정보 및 위치정보 기반의 정보를 일반인들에게 손쉽게 제공할 수 있는 서비스가 요구되고 있다. 본 연구에서는 RFID 태그와 2차원 바코드를 이용하여 위치정보를 손쉽게 제공할 수 있는 새로운 개념의 기준점 프로토타입을 제작하였다. 본 논문에서는 개발된 인텔리전트 기준점을 실용화하여 실제로 서비스하기 위해 필요한 사항에 대해 고려하여 보았으며, 실제 테스트를 통해 사용 가능성을 검증해보았다.

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Optimal 및 Sub-optimal 기준점을 사용한 DGPS 설계 및 성능평가 (Design and Performance Evaluation of DGPS Based on Optimal and Sub-optimal Reference Point)

  • 고광섭;홍성래;정세모
    • 한국정보통신학회논문지
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    • 제2권3호
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    • pp.343-352
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    • 1998
  • DGPS 이용으로 Standalone GPS의 정확도와 동일한 위성을 사용하는 2개 또는 그 이상의 사용자 수신기에서 생기는 공통오차제거가 가능하게 되었다. 정확한 기준점을 갖는 DGPS 시스템은 기준국과 사용자 수신기에서 발생하는 공통오차를 계산하여 사용자 수신기의 의사거리 보정을 한다. 정확한 기준점 측정은 특정한 측량기구 시스템을 이용하여 각 위성의 parameter를 측정하고 후 처리하여 얻게되므로 상당한 시간과 비용이 불가피하다. 본 연구에서는 측량기준점을 바탕으로 한 DGPS시스템과 Sub-optimal 기준점을 이용한 DGPS 시스템을 자체 구현하였다. 각각의 RTCM 보정 데이터를 이용하여 얻은 오차범위를 분석 평가하였다. 연구결과 이 시스템이 민간 및 군의 특정한 해양활동 사용시에 활용될 수 있음을 보였다.

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방향 패턴의 레이블링을 이용한 지문영상의 Core Point 검출 (Core Point Detection using Orientation Pattern Labeling in Fingerprint)

  • 이경환;박철현;오상근;박길흠
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2001년도 제14회 신호처리 합동 학술대회 논문집
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    • pp.429-432
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    • 2001
  • 지문영상의 특이점(Singularities) 중의 하나인 Core Point는 대부분의 지문인증 시스템에서 기준점(Reference Point)으로 사용되고 있다. 또한 Core Point의 검출은 전체 지문인증 시스템의 가장 기본적인 단계로서 전체 시스템의 성능에 많은 영향을 준다. 본 논문에서는 지문 영상의 방향 패턴(Orientation Pattern)과 이의 리레이블링(Re-labeling)을 이용한 Core Point 검출 방법을 제안하고, 기존의 Poincare Index를 이용하는 방법 및 Sine Map을 이응한 방법과 비교, 분석하였다.

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EPD 신호검출에 의한 플라즈마식각공정의 이상검출 (Malfunction detection in plasma etching process using EPD signal trace)

  • 이종민;차상엽;최순혁;우광방
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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    • pp.1360-1363
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    • 1996
  • EPD(End Point Detection) is used to decide etching degree of layer which must be removed at wafer etching process in plasma etching process which is one of the most important process in semiconductor manufacturing. In this thesis, the method which detects malfunction of etching process in real-time will be discussed. Several EPD signal traces are collected in normal plasma etching condition and used as reference EPD signal traces. Critical points can be detected by applying differentiation and zero-crossing techniques to reference EPD signal. Mean and standard deviation of critical parameters which is memorized from reference EPD signal are calculated and these determine the lower and higher limit of control chart. And by applying statical control chart to EPD signals which are collected in real etching process malfunctions of process are detected in real-time. By means of applying this method to the real etching process we prove our method can accurately detect the malfunction of etching process and can compensate disadvantage of current industrial method.

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Method of Making the Distribution of Voxels Uniform within the Volumetric 3D image Space

  • Lin, Yuanfang;Liu, Xu;Xie, Xiaoyan;Liu, Xiangdong;Li, Haifeng
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.1138-1141
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    • 2008
  • By defining a uniform reference point array corresponding to the 3D voxel array and abandoning voxels whose deviations from their respective reference points exceed a given tolerance, the distribution of voxels within the volumetric 3D image space gets uniform, effects of non-uniform distribution upon the image reconstructing are eased.

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수직형 마이크로 자이로스코프의 연성 진동과 영점 출력

  • 이승엽;전도영;김택현
    • 소음진동
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    • 제10권5호
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    • pp.880-885
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    • 2000
  • In a verical type, vibratory gyroscope, the coupled motion between the reference and sensing vibrations causes the zero-point output which means non-zero sensing vibration without angular velocity. This structural coupling leaks to an inherent discrepancy between the natural frequencies of the reference and sensing oscillations, causing the degradation of the sensing performance and dynamic stability. In this paper, the dynamic characteristics associated the coupling phenomenon are theoretically analyzed. Effects of reference frequency and coupling factor on the rotational direction and amplitude of elliptic oscillation are studied. A technique to predict the existence of curve veering of crossing in frequency trajectories is introduced to apply the design of micro gyroscopes with decoupled structures.

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능동전력필터의 정밀 기준신호 발생기 (Accurate Current Reference Generator for Active Power Filters)

  • 배병열;전영수;한병문;소용철
    • 전력전자학회:학술대회논문집
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    • 전력전자학회 2004년도 전력전자학술대회 논문집(2)
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    • pp.575-578
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    • 2004
  • The performance of an active power filter(APF) depends on the inverter characteristic, the control method, and the accuracy of reference signal generator. The accuracy of reference generator is the most critical item to determine the performance of active power filter. This paper introduces a novel reference signal generator composed of improved adaptive predictive filter. The performance of proposed reference signal generator was first verified through a simulation with MATLAB. Furthermore, the application of feasibility was evaluated through experimenting with a single-phase APF prototype based on the proposed reference generator, which was implemented using the TMS320C31 floating-point signal processor. Both simulations and experimental results confirm that our reference signal generator can be used successfully in practical active power filters.

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Robustness of optimized FPID controller against uncertainty and disturbance by fractional nonlinear model for research nuclear reactor

  • Zare, Nafiseh;Jahanfarnia, Gholamreza;Khorshidi, Abdollah;Soltani, Jamshid
    • Nuclear Engineering and Technology
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    • 제52권9호
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    • pp.2017-2024
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    • 2020
  • In this study, a fractional order proportional integral derivative (FOPID) controller is designed to create the reference power trajectory and to conquer the uncertainties and external disturbances. A fractional nonlinear model was utilized to describe the nuclear reactor dynamic behaviour considering thermal-hydraulic effects. The controller parameters were tuned using optimization method in Matlab/Simulink. The FOPID controller was simulated using Matlab/Simulink and the controller performance was evaluated for Hard variation of the reference power and compared with that of integer order a proportional integral derivative (IOPID) controller by two models of fractional neutron point kinetic (FNPK) and classical neutron point kinetic (CNPK). Also, the FOPID controller robustness was appraised against the external disturbance and uncertainties. Simulation results showed that the FOPID controller has the faster response of the control attempt signal and the smaller tracking error with respect to the IOPID in tracking the reference power trajectory. In addition, the results demonstrated the ability of FOPID controller in disturbance rejection and exhibited the good robustness of controller against uncertainty.

복합하중을 받는 평판에 존재하는 반타원 표면균열의 공학적 탄소성 파괴해석법 (Engineering Elastic-Plastic Fracture Analysis for Semi-Elliptical Surface Cracked Plates Under Combined Bending and Tension)

  • 심도준;김윤재;최재붕;김영진
    • 대한기계학회논문집A
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    • 제26권6호
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    • pp.1127-1134
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    • 2002
  • The present paper provides an engineering J estimation equation for surface cracked plates under combined bending and tension. The proposed equation is based on the reference stress approach, and the most relevant normalising loads to define the reference stress for accurate J estimations are given for surface cracked plates under combined bending and tension. Comparisons with J results from extensive 3-D FE analyses, covering a wide range of crack geometry, plate geometry and loading combination, show overall good agreement not only at the deepest point but also at arbitrary points along the crack front. for pure tension, agreement between the estimated J and the FE results is excellent, even at the surface point. On the other hand, for pure bending and combined bending and tension, the estimated J values become less accurate for locations close to the surface point. Thus the results in this paper will be useful to assess short-term fracture or low cycle fatigue of surface defects in plates under combined bending and tension.

초고층 건축물의 거주자 생활환경을 위한 평가기준 개선에 관한 연구 (A study on the establishment a point of reference for the improvement of a dweller's life environment at skyscraper)

  • 이건;김길중;이현철;박현구;고성석
    • 한국주거학회:학술대회논문집
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    • 한국주거학회 2009년 춘계학술발표대회 논문집
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    • pp.355-360
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    • 2009
  • Nowadays, the condition of overcrowded cities has raised a question which is insufficient land in cities, and has gotten worse because of the influx of the population continuously. It has rapidly constructed a skyscraper increasingly that the solution to secure a living space against these overcrowded cities until 2000, but these are already positioning itself as one of the new type of residence. The necessity of skyscraper as facilities of residence inside cities has be available both a solution for overcrowded cities and a meaning for a symbol of its represented a landmark. However, constructing skyscrapers indiscreetly can not guarantee dweller's life environment, and it contains risks unless design and facilities criteria are provided. Now, a skyscraper as a new substitute constituting a living space in the future for overcrowded cities deals with a systematic correlation between a city and construction. Therefore the aim of this study were to indicate a method for improvement of dweller's life environment at skyscraper through establishing a point of reference to inculcate them for a sustainable skyscraper from now on.

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