• Title/Summary/Keyword: $\partial$-estimate

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Fast 360° Sound Source Localization using Signal Energies and Partial Cross Correlation for TDOA Computation

  • Yiwere, Mariam;Rhee, Eun Joo
    • Journal of Information Technology Applications and Management
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    • v.24 no.1
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    • pp.157-167
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    • 2017
  • This paper proposes a simple sound source localization (SSL) method based on signal energies comparison and partial cross correlation for TDOA computation. Many sound source localization methods include multiple TDOA computations in order to eliminate front-back confusion. Multiple TDOA computations however increase the methods' computation times which need to be as minimal as possible for real-time applications. Our aim in this paper is to achieve the same results of localization using fewer computations. Using three microphones, we first compare signal energies to predict which quadrant the sound source is in, and then we use partial cross correlation to estimate the TDOA value before computing the azimuth value. Also, we apply a threshold value to reinforce our prediction method. Our experimental results show that the proposed method has less computation time; spending approximately 30% less time than previous three microphone methods.

Analyzing Separation and Weight of Partial Equilibrium Welfare Effects and Spillover Effects of Restriction on the Fishery Market (수산물시장규제의 부분균형후생효과와 파급효과의 분리와 비중분석)

  • Park, Hoan-Jae
    • The Journal of Fisheries Business Administration
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    • v.47 no.1
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    • pp.101-113
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    • 2016
  • The purpose of this paper is to analyze theoretically and empirically spillover effects of fishery quota on related markets through their demand curves. Theoretically, the spillover effects of a change in quota can be captured through the directly distorted market alone by computing surpluses associated with the new and old equilibrium. This study estimates empirically demand functions in the context of both the partial equilibrium and general equilibrium. The spillover effect can be computed from the difference between these two estimates. The econometric methodology to estimate the demand curves in the context of general equilibrium is presented and illustrated. The empirical result of fishery markets shows that spillover effects transmitted across other markets are not small and approximately account for 43.3% of the partial equilibrium welfare effects.

Improved Model for Maximum Power Point Tracking (MPPT) of Solar System (태양광 시스템의 최대 전력지점 추적(MPPT) 정확도 향상을 위한 모델링)

  • Lee, YoungHyun;Lee, Jonghwan
    • Journal of the Semiconductor & Display Technology
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    • v.21 no.1
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    • pp.114-118
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    • 2022
  • The photovoltaic system is affected by various conditions such as temperature and irradiance. Because non-uniform irradiation and partial shading conditions affect the entire string of cells connected in series, a bypass diode is used to bypass the current flow normally. In order to find the maximum power point in partial shade conditions, it is necessary to estimate various methods of maximum power point tracking. In this paper, the hybrid method of MPPT using Lambert W function and perturbation & observation algorithm is proposed under partial shading conditions. The simulation results are obtained using MATLAB/Simulink and shows the improvement of the accuracy of MPPT.

A Dynamic Graphical Method for Transformations and Curvature Specifications in Regression

  • Seo, Han-Son;Yoon, Min
    • The Korean Journal of Applied Statistics
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    • v.22 no.1
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    • pp.189-195
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    • 2009
  • A dynamic graphical procedure is suggested to estimate optimal response transformation parameter and a curvature function of covariates in the regression model. Augmented partial residual plot is chosen for specifying a curvature. The proposed method is compared with a different approach (Soo, 2007) and is investigated efficiency by applying it to the real and the artificial data. The method is also extended to the 3D graphical situations.

A Modified Computing Algorithm for Raking Ratio Estimation Subject to Partial Marginal Information

  • Son, Chang Kyoon
    • Communications for Statistical Applications and Methods
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    • v.11 no.2
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    • pp.419-433
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    • 2004
  • We suggest the modified computing algorithm for raking ratio estimation under the assumption that the population total is partially known, and the sample total is completely known about survey variable in contingency table. We show that the proposed estimation procedure is useful to estimate the population cell count in this situation through an empirical study.

Performance Evaluation of SHF Sensor for Partial Discharge Signal Detection on DC Rectifier (DC 정류기 부분방전 신호검출을 위한 SHF 센서의 성능평가)

  • Jung, Ho-Sung;Park, Young;Na, Hee-Seung;Jang, Soon-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.7
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    • pp.1056-1060
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    • 2012
  • Online monitoring system is becoming an essential element of railway traction system for utilized to condition based malignance management and various techniques currently employed in railway traction system. Among the various techniques, it is efficient to detect partial discharge signals by electromagnetic wave detection in order to detect insulation fault of rectifier. Although VHF (Very High Frequency), UHF (Ultra High Frequency) sensors were adopted to detect partial discharge of power facilities, due to characteristics of urban railway, excessive noise occurs from 500 MHz to 1.5 GHz on UHF bandwidth. In this paper a new measurement system able to monitoring the conditions of power facilities on DC substation in metro was studied and set up. The system uses UHF sensors to measure the partial discharge of the rectifier due to electric faulting and dielectric breakdown. Comparison and estimation for performance of SHF sensor which had devised to detect partial discharge signal of urban railway rectifier has conducted. In order to estimate performance of SHF sensor, we have compared the sensor with existing UHF sensor on sensitivity upon frequency bandwidth generated by pulse generator, and also we have verified performance of the SHF sensor by detection results of partial discharge signal from urban railway rectifier.

Surface Tension of Molten Ag-Sn and Au-Cu Alloys at Different Oxygen Partial Pressures (다양한 산소분압에 따른 용융 Ag-Sn 및 Ag-Cu 합금의 표면장력)

  • Min, Soon-Ki;Lee, Joon-Ho
    • Korean Journal of Materials Research
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    • v.19 no.1
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    • pp.13-17
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    • 2009
  • A semi-empirical method to estimate the surface tension of molten alloys at different oxygen partial pressures is suggested in this study. The surface tension of molten Ag-Sn and Ag-Cu alloys were calculated using the Butler equation with the surface tension value of pure substance at a given oxygen partial pressure. The oxygen partial pressure ranges were $2.86{\times}10^{-12}$$1.24{\times}10^{-9}$ Pa for the Ag-Sn system and $2.27{\times}10^{-11}$$5.68{\times}10^{-4}$ Pa for the Ag-Cu system. In this calculation, the interactions of the adsorbed oxygen with other metallic constituents were ignored. The calculated results of the Ag-Sn alloys were in reasonable accordance with the experimental data within a difference of 8%. For the Ag-Cu alloy system at a higher oxygen partial pressure, the surface tension initially decreased but showed a minimum at $X_{Ag}$ = 0.05 to increase as the silver content increased. This behavior appears to be related to the oxygen adsorption and the corresponding surface segregation of the constituent with a lower surface tension. Nevertheless, the calculated results of the Ag-Cu alloys with the present model were in good agreement with the experimental data within a difference of 10%.

BERGMAN KERNEL ESTIMATES FOR GENERALIZED FOCK SPACES

  • Cho, Hong Rae;Park, Soohyun
    • East Asian mathematical journal
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    • v.33 no.1
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    • pp.37-44
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    • 2017
  • We will prove size estimates of the Bergman kernel for the generalized Fock space ${\mathcal{F}}^2_{\varphi}$, where ${\varphi}$ belongs to the class $\mathcal{W} $. The main tool for the proof is to use the estimate on the canonical solution to the ${\bar{\partial}}$-equation. We use Delin's weighted $L^2$-estimate ([3], [6]) for it.

Monotone Local Linear Quasi-Likelihood Response Curve Estimates

  • Park, Dong-Ryeon
    • Communications for Statistical Applications and Methods
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    • v.13 no.2
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    • pp.273-283
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    • 2006
  • In bioassay, the response curve is usually assumed monotone increasing, but its exact form is unknown, so it is very difficult to select the proper functional form for the parametric model. Therefore, we should probably use the nonparametric regression model rather than the parametric model unless we have at least the partial information about the true response curve. However, it is well known that the nonparametric regression estimate is not necessarily monotone. Therefore the monotonizing transformation technique is of course required. In this paper, we compare the finite sample properties of the monotone transformation methods which can be applied to the local linear quasi-likelihood response curve estimate.