• Title/Summary/Keyword: Point Estimate Method

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A Robust Power Transmission Lines Detection Method Based on Probabilistic Estimation of Vanishing Point (확률적인 소실점 추정 기법에 기반한 강인한 송전선 검출 방법)

  • Yoo, Ju Han;Kim, Dong Hwan;Lee, Seok;Park, Sung-Kee
    • The Journal of Korea Robotics Society
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    • v.10 no.1
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    • pp.9-15
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    • 2015
  • We present a robust power transmission lines detection method based on vanishing point estimation. Vanishing point estimation can be helpful to detect power transmission lines because parallel lines converge on the vanishing point in a projected 2D image. However, it is not easy to estimate the vanishing point correctly in an image with complex background. Thus, we first propose a vanishing point estimation method on power transmission lines by using a probabilistic voting procedure based on intersection points of line segments. In images obtained by our system, power transmission lines are located in a fan-shaped area centered on this estimated vanishing point, and therefore we select the line segments that converge to the estimated vanishing point as candidate line segments for power transmission lines only in this fan-shaped area. Finally, we detect the power transmission lines from these candidate line segments. Experimental results show that the proposed method is robust to noise and efficient to detect power transmission lines.

Template-Based Reconstruction of Surface Mesh Animation from Point Cloud Animation

  • Park, Sang Il;Lim, Seong-Jae
    • ETRI Journal
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    • v.36 no.6
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    • pp.1008-1015
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    • 2014
  • In this paper, we present a method for reconstructing a surface mesh animation sequence from point cloud animation data. We mainly focus on the articulated body of a subject - the motion of which can be roughly described by its internal skeletal structure. The point cloud data is assumed to be captured independently without any inter-frame correspondence information. Using a template model that resembles the given subject, our basic idea for reconstructing the mesh animation is to deform the template model to fit to the point cloud (on a frame-by-frame basis) while maintaining inter-frame coherence. We first estimate the skeletal motion from the point cloud data. After applying the skeletal motion to the template surface, we refine it to fit to the point cloud data. We demonstrate the viability of the method by applying it to reconstruct a fast dancing motion.

Optimal Coordination of Intermittent Distributed Generation with Probabilistic Power Flow

  • Xing, Haijun;Cheng, Haozhong;Zhang, Yi
    • Journal of Electrical Engineering and Technology
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    • v.10 no.6
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    • pp.2211-2220
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    • 2015
  • This paper analyzes multiple active management (AM) techniques of active distribution network (ADN), and proposes an optimal coordination model of intermittent distributed generation (IDG) accommodation considering the timing characteristic of load and IDG. The objective of the model is to maximize the daily amount of IDG accommodation under the uncertainties of IDG and load. Various active management techniques such as IDG curtailment, on-load tap changer (OLTC) tap adjusting, voltage regulator (VR) tap adjusting, shunt capacitors compensation and so on are fully considered. Genetic algorithm and Primal-Dual Interior Point Method (PDIPM) is used for the model solving. Point estimate method is used to simulate the uncertainties. Different scenarios are selected for the IDG accommodation capability investigation under different active management schemes. Finally a modified IEEE 123 case is used to testify the proposed accommodation model, the results show that the active management can largely increase the IDG accommodation and penetration.

Development Estimation Method to Estimate Sensing Ability of Smart Sensors (지능센서의 센싱능력 평가를 위한 평가기법 개발)

  • Hwang Seong-Youn;Murozono Masahiko;Kim Young-Moon;Hong Dong-Pyo
    • Transactions of the Korean Society of Machine Tool Engineers
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    • v.15 no.2
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    • pp.99-106
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    • 2006
  • In this paper, the new method that estimates a sensing ability of smart sensor will be proposed. A study is estimation method that evaluates sensing ability about smart sensor respectively. According to acceleration(g) and displacement changing, we estimated sensing ability of smart sensor using SAI(Sensing Ability Index) method respectively. Smart sensors was made fer experiment. The types of smart sensor are two types(hard and soft smart sensor). Smart sensors developed for recognition of material. Experiment and analysis are executed for estimate the SAI method. In develop a smart sensor, the SAI method will be useful for finding optical design condition of smart sensor that can sense a material. And then dynamic characteristics of smart sensors(frequency changing, acceleration changing, critical point, etc.) are evaluated respectively through new method(SAI) that use the power spectrum density. Dynamic characteristic of sensor is evaluated with SAI method relatively. We can use the SAI for finding critical point of smart sensor, too.

Camera Motion Parameter Estimation Technique using 2D Homography and LM Method based on Invariant Features

  • Cha, Jeong-Hee
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.5 no.4
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    • pp.297-301
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    • 2005
  • In this paper, we propose a method to estimate camera motion parameter based on invariant point features. Typically, feature information of image has drawbacks, it is variable to camera viewpoint, and therefore information quantity increases after time. The LM(Levenberg-Marquardt) method using nonlinear minimum square evaluation for camera extrinsic parameter estimation also has a weak point, which has different iteration number for approaching the minimal point according to the initial values and convergence time increases if the process run into a local minimum. In order to complement these shortfalls, we, first propose constructing feature models using invariant vector of geometry. Secondly, we propose a two-stage calculation method to improve accuracy and convergence by using homography and LM method. In the experiment, we compare and analyze the proposed method with existing method to demonstrate the superiority of the proposed algorithms.

Approximate Method in Estimating Sensitivity Responses to Variations in Delayed Neutron Energy Spectra

  • J. Yoo;H. S. Shin;T. Y. Song;Park, W. S.
    • Proceedings of the Korean Nuclear Society Conference
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    • 1997.10a
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    • pp.85-90
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    • 1997
  • Previous our numerical results in computing point kinetics equations show a possibility in developing approximations to estimate sensitivity responses of nuclear reactor We recalculate sensitivity responses by maintaining the corrections with first order of sensitivity parameter. We present a method for computing sensitivity responses of nuclear reactor based on an approximation derived from point kinetics equations. Exploiting this approximation, we found that the first order approximation works to estimate variations in the time to reach peak power because of their linear dependence on a sensitivity parameter, and that there are errors in estimating the peak power in the first order approximation for larger sensitivity parameters. To confirm legitimacy of our approximation, these approximate results are compared with exact results obtained from our previous numerical study.

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Nonparametric Detection of a Discontinuity Point in the Variance Function with the Second Moment Function

  • Huh, Jib
    • Journal of the Korean Data and Information Science Society
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    • v.16 no.3
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    • pp.591-601
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    • 2005
  • In this paper we consider detection of a discontinuity point in the variance function. When the mean function is discontinuous at a point, the variance function is usually discontinuous at the point. In this case, we had better estimate the location of the discontinuity point with the mean function rather than the variance function. On the other hand, the variance function only has a discontinuity point. The target function in order to estimate the location can be used the second moment function since the variance function and the second moment function have the same location and jump size of the discontinuity point. We propose a nonparametric detection method of the discontinuity point with the second moment function. We give the asymptotic results of these estimators. Computer simulation demonstrates the improved performance of the method over the existing ones.

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Species Diversity of a Stratified Hornbeam Community in Kwangneung Forest (광릉산림에 있어서 서나무군집의 층에 따른 종다양성에 관한 연구)

  • 이광석;장남기
    • Asian Journal of Turfgrass Science
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    • v.9 no.2
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    • pp.131-136
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    • 1995
  • The herb, shrub, understory and canopy strata, which arbitrarily delineated by size classes, were sampled separately. The former one were sampled by the pin-point quadrat method. And remaining three by size quadrats, diversity (H= =$\Sigma$ Pi log Pi) of of each stratum was estimated for each set of census data. Species diversity within a stratum was independent of sample plot size above a minimum cumulative area. Diversity based on plotless and plot samples could he determined by the same equation, and by pooling the data needed to estimate diversity of each stratum.

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Analysis of Tubular Structures in Medical Imaging

  • Kim, Jin-Woo
    • Journal of information and communication convergence engineering
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    • v.7 no.4
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    • pp.545-550
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    • 2009
  • A method fully utilizing multiscale line filter responses is presented to estimate the point spread function(PSF) of a CT scanner and diameters of small tubular structures based on the PSF. The estimation problem is formulated as a least square fitting of a sequence of multiscale responses obtained at each medical axis point to the precomputed multiscale response curve for the ideal line model. The method was validated through phantom experiments and demonstrated through phantom experiments and demonstrated to accurately measure small-diameter structures which are significantly overestimated by conventional methods based on the full width half maximum(FWHM) and zero-crossing edge detection.

Thermography-based coating thickness estimation for steel structures using model-agnostic meta-learning

  • Jun Lee;Soonkyu Hwang;Kiyoung Kim;Hoon Sohn
    • Smart Structures and Systems
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    • v.32 no.2
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    • pp.123-133
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    • 2023
  • This paper proposes a thermography-based coating thickness estimation method for steel structures using model-agnostic meta-learning. In the proposed method, a halogen lamp generates heat energy on the coating surface of a steel structure, and the resulting heat responses are measured using an infrared (IR) camera. The measured heat responses are then analyzed using model-agnostic meta-learning to estimate the coating thickness, which is visualized throughout the inspection surface of the steel structure. Current coating thickness estimation methods rely on point measurement and their inspection area is limited to a single point, whereas the proposed method can inspect a larger area with higher accuracy. In contrast to previous ANN-based methods, which require a large amount of data for training and validation, the proposed method can estimate the coating thickness using only 10- pixel points for each material. In addition, the proposed model has broader applicability than previous methods, allowing it to be applied to various materials after meta-training. The performance of the proposed method was validated using laboratory-scale and field tests with different coating materials; the results demonstrated that the error of the proposed method was less than 5% when estimating coating thicknesses ranging from 40 to 500 ㎛.