• 제목/요약/키워드: Characteristic Estimation

검색결과 752건 처리시간 0.023초

Optimal Design of the Adaptive Searching Estimation in Spatial Sampling

  • Pyong Namkung;Byun, Jong-Seok
    • Communications for Statistical Applications and Methods
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    • 제8권1호
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    • pp.73-85
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    • 2001
  • The spatial population existing in a plane ares, such as an animal or aerial population, have certain relationships among regions which are located within a fixed distance from one selected region. We consider with the adaptive searching estimation in spatial sampling for a spatial population. The adaptive searching estimation depends on values of sample points during the survey and on the nature of the surfaces under investigation. In this paper we study the estimation by the adaptive searching in a spatial sampling for the purpose of estimating the area possessing a particular characteristic in a spatial population. From the viewpoint of adaptive searching, we empirically compare systematic sampling with stratified sampling in spatial sampling through the simulation data.

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Ti:$LiNbO_3$ 진행파 광변조기의 FEM 전극해석 및 대역폭 예측 (FEM analysis of Ti:$LiNbO_3$ optical modulator's traveling-wave electrodes and estimation of modulation band-width)

  • 김창민;한상필
    • 전자공학회논문지A
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    • 제32A권2호
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    • pp.96-110
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    • 1995
  • Traveling-wave electrodes for the high-speed Ti:LiNbO$_{3}$ modulators are designed. For a solution to the problems of 1) phase-velocity mismatching between the optical wave and the Modulating M/W, 2) M/W electrode characteristic impedance mismateching, we assume devices with 1$\mu$m thick SiO$_{2}$ buffer layer between the electrode and the Ti:LiNbO$_{3}$ substrate. The electrode analyses are performed by the FEM using the second-order triangular elements. The optimum design parameters to satisfy the phase-velocity matching and the characteristic impedance matching are sought for. By use of the analyses' results, a Mach-Zehnder optical modulator with a CPW electrode is designed as an example. the band-width estimation is also illustrated.

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충진제와 실란처리에 따른 에폭시 복합체의 파괴시간 예측 (An Estimation of Breakdown Time of the Epoxy Composites according to Filler and Silane Treatment)

  • 신철기
    • 한국전기전자재료학회논문지
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    • 제20권9호
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    • pp.793-797
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    • 2007
  • In this paper, the long time breakdown characteristic of the epoxy composite, which is widely used in the insulation system for high voltage application, was estimated with Weibull distribution. In the procedure of the estimation, the short time breakdown characteristics for the epoxy composite specimens, which were made with the variation of hardener and/or filler, were tested firstly. Then the long time voltage-to-time test was implemented. Finally, the long time breakdown voltage of each specimen was estimated with the parameters obtained from the statistical treatment with Weibull distribution. Base on the results, it has been found that the optimal weight ratio of epoxy resin/hardener/filler that has the excellent long time breakdown characteristic was 100/100/65. It was due to the silane treatment which relieves the electric field at the interface between filler and epoxy.

스펙트럼 특성행렬을 이용한 효율적인 반사 스펙트럼 복원 방법 (Efficient Method for Recovering Spectral Reflectance Using Spectrum Characteristic Matrix)

  • 심규동;박종일
    • 한국멀티미디어학회논문지
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    • 제18권12호
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    • pp.1439-1444
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    • 2015
  • Measuring spectral reflectance can be regarded as obtaining inherent color parameters, and spectral reflectance has been used in image processing. Model-based spectrum recovering, one of the method for obtaining spectral reflectance, uses ordinary camera with multiple illuminations. Conventional model-based methods allow to recover spectral reflectance efficiently by using only a few parameters, however it requires some parameters such as power spectrum of illuminations and spectrum sensitivity of camera. In this paper, we propose an enhanced model-based spectrum recovering method without pre-measured parameters: power spectrum of illuminations and spectrum sensitivity of camera. Instead of measuring each parameters, spectral reflectance can be efficiently recovered by estimating and using the spectrum characteristic matrix which contains spectrum parameters: basis function, power spectrum of illumination, and spectrum sensitivity of camera. The spectrum characteristic matrix can be easily estimated using captured images from scenes with color checker under multiple illuminations. Additionally, we suggest fast recovering method preserving positive constraint of spectrum by nonnegative basis function of spectral reflectance. Results of our method showed accurately reconstructed spectral reflectance and fast constrained estimation with unmeasured camera and illumination. As our method could be conducted conveniently, measuring spectral reflectance is expected to be widely used.

복합재료 기준형 블레이드를 장착한 축소 힌지없는 허브시스템의 진동특성과 피로수명 예측 (The Vibration Characteristic and Fatigue Life Estimation of a Small-scaled Hingeless Hub System with Composite Rectangular Blades)

  • 송근웅;김준호;김덕관;주진
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2003년도 추계학술대회논문집
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    • pp.310-315
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    • 2003
  • This paper described that rotating test and fatigue test of a small-scale hingeless hub system with composite rectangular blades. Generally Rotating stability and fatigue test technique is one of Key-technology on test and evaluation for helicopter rotor system Rotating test of hingeless rotor system was achieved by means of rotor vibration characteristic and aeroelastic stability test GSRTS, equipped with hydraulic actuator and 6-component rotating balance was used to test hingeless rotor system especially for an observation of blade motion including flawing, lagging and feathering. Rotating test was done in hover and forward flight condition. Small-scaled blade fatigue test condition was determined by blade load analysis with the reference table of composite materials(S-N curve). Fatigue test bench was developed for the estimation of blade fatigue life, and tested its characteristic.

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단일 전력단 능동 클램프형 고주파 공진 인버터의 특성 평가 (Characteristic Estimation of Single-Stage Active-Clamp Type High Frequency Resonant Inverter)

  • 원재선;강진욱;김동희
    • 대한전기학회논문지:전기기기및에너지변환시스템부문B
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    • 제53권2호
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    • pp.114-122
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    • 2004
  • This paper presents a novel single-stage active-clamp type high frequency resonant inverter. The proposed topology is integrated full-bridge boost rectifier as power factor corrector and active-clamp type high frequency resonant inverter into a single-stage. The input stage of the full-bridge boost rectifier works in discontinuous conduction mode(DCM) with constant duty cycle and variable switching frequency. So that a boost converter makes the line current follow naturally the sinusoidal line voltage waveform. By adding additional active-clamp circuit to conventional class-E high frequency resonant inverter, main switch of inverter part operates not only at Zero-Voltage-Switching mode but also reduces the switching voltage stress of main switch. Simulation results have demonstrated the feasibility of the proposed high frequency resonant inverter. Characteristics values based on characteristics estimation through circuit analysis is given as basis data in design procedure. Also, experimental results are presented to verify theoretical discussion. This proposed inverter will be able to be practically used as a power supply in the fields of induction heating applications, fluorescent lamp and DC-DC converter etc.

Analysis of Real-Time Estimation Method Based on Hidden Markov Models for Battery System States of Health

  • Piao, Changhao;Li, Zuncheng;Lu, Sheng;Jin, Zhekui;Cho, Chongdu
    • Journal of Power Electronics
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    • 제16권1호
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    • pp.217-226
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    • 2016
  • A new method is proposed based on a hidden Markov model (HMM) to estimate and analyze battery states of health. Battery system health states are defined according to the relationship between internal resistance and lifetime of cells. The source data (terminal voltages and currents) can be obtained from vehicular battery models. A characteristic value extraction method is proposed for HMM. A recognition framework and testing datasets are built to test the estimation rates of different states. Test results show that the estimation rates achieved based on this method are above 90% under single conditions. The method achieves the same results under hybrid conditions. We can also use the HMMs that correspond to hybrid conditions to estimate the states under a single condition. Therefore, this method can achieve the purpose of the study in estimating battery life states. Only voltage and current are used in this method, thereby establishing its simplicity compared with other methods. The batteries can also be tested online, and the method can be used for online prediction.

Simulation of the Blood Pressure Estimation Using the Artery Compliance Model and Pulsation Waveform Model

  • Jeon, Ahyoung;Ro, Junghoon;Kim, Jaehyung;Baik, Seongwan;Jeon, Gyerok
    • 센서학회지
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    • 제22권1호
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    • pp.38-43
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    • 2013
  • In this study, the artery's compliance model and the pulsation waveform model was proposed to estimate blood pressure without applying HPF (High Pass Filter) on signal measured by the oscillometric method. The method proposed in the study considered two ways of estimating blood pressure. The first method of estimating blood pressure is by comparing and analyzing changes in pulsation waveform's dicrotic notch region during each cardiac period. The second method is by comparing and analyzing morphological changes in the pulsation waveform during each cardiac period, which occur in response to the change in pressure applied on the cuff. To implement these methods, we proposed the compliance model and the pulsation waveform model of the artery based on hemodynamic theory, and then conducted various simulations. The artery model presented in this study only took artery's compliance into account. Then, a pulsation waveform model was suggested, which uses characteristic changes in the pulsation waveform to estimate blood pressure. In addition, characteristic changes were observed in arterial volume by applying artery's pulsation waveform to the compliance model. The pulsation waveform model was suggested to estimate blood pressure using characteristic changes of the pulsation waveform in the arteries. This model was composed of the sum of sine waves and a Fourier's series in combination form up to 10th harmonics components of the sinusoidal waveform. Then characteristic of arterial volume change was observed by inputting pulsation waveform into the compliance model. The characteristic changes were also observed in the pulsation waveform by mapping the arterial volume change in accordance with applied cuff's pressure change to the pulsation waveform's change according to applied pressure changes by cuff. The systolic and diastolic blood pressures were estimated by applying positional change of pulsation waveform's dicrotic notch region.

도시특성지표 기반 공간개발 패턴 추정에 관한 연구 - 강남지역을 대상으로 - (An Estimation of the Spatial Development Patterns based on the Characteristic City Indicators - The Case of Gangnam District -)

  • 장성만;이창효
    • Spatial Information Research
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    • 제23권3호
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    • pp.23-33
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    • 2015
  • 현재 계획단계에서 구득하여 활용할 수 있는 토지이용 관련 정보는 시도, 시군구, 그리고 읍면동과 같은 집계된 단위의 자료가 주를 이루고 있어, 미시적 공간단위에서의 변화 양상을 파악하기에는 근본적인 한계가 존재한다. 본 연구의 목적은 존 내 물리적 도시특성지표를 바탕으로 공간 개발패턴을 추정하는 방법론을 개발하는데 있다. 본 연구에서는 강남지역을 육각형 픽셀로 분할하고 각 공간분석단위별로 판매 및 업무의 건축물 개발강도를 단계별로 구분하여 도시의 공간적 특성이 판매 및 업무에 어떠한 영향을 미치는가를 다항 로지스틱 회귀분석을 통해 수행하였다. 분석결과 도로와 버스정류장과의 거리가 증가하면 밀도 개발 확률이 감소하며, 수계와의 거리가 증가하면 밀도 개발 확률이 높아짐을 확인하였다. 본 연구의 방법론과 결과물은 도시계획분야에서 집계된 자료를 미시적 공간으로 세분하는 방법론으로 활용될 것으로 판단된다.