• 제목/요약/키워드: Quadratic Loss

검색결과 118건 처리시간 0.028초

Sufficient Conditions for the Admissibility of Estimators in the Multiparameter Exponential Family

  • Dong, Kyung-Hwa;Kim, Byung-Hwee
    • Journal of the Korean Statistical Society
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    • 제22권1호
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    • pp.55-69
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    • 1993
  • Consider the problem of estimating an arbitrary continuous vector function under a weighted quadratic loss in the multiparameter exponential family with the density of the natural form. We first provide, using Blyth's (1951) method, a set of sufficient conditions for the admisibility of (possibly generalized Bayes) estimators and then treat some examples for normal, Poisson, and gamma distributions as applications of the main result.

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An approach to improving the Lindley estimator

  • Park, Tae-Ryoung;Baek, Hoh-Yoo
    • Journal of the Korean Data and Information Science Society
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    • 제22권6호
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    • pp.1251-1256
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    • 2011
  • Consider a p-variate ($p{\geq}4$) normal distribution with mean ${\theta}$ and identity covariance matrix. Using a simple property of noncentral chi square distribution, the generalized Bayes estimators dominating the Lindley estimator under quadratic loss are given based on the methods of Brown, Brewster and Zidek for estimating a normal variance. This result can be extended the cases where covariance matrix is completely unknown or ${\Sigma}={\sigma}^2I$ for an unknown scalar ${\sigma}^2$.

Improvement of the Modified James-Stein Estimator with Shrinkage Point and Constraints on the Norm

  • Kim, Jae Hyun;Baek, Hoh Yoo
    • 통합자연과학논문집
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    • 제6권4호
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    • pp.251-255
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    • 2013
  • For the mean vector of a p-variate normal distribution ($p{\geq}4$), the optimal estimation within the class of modified James-Stein type decision rules under the quadratic loss is given when the underlying distribution is that of a variance mixture of normals and when the norm ${\parallel}{\theta}-\bar{\theta}1{\parallel}$ it known.

주파수 변조 DANTE를 이용한 자화율 효과의 감소 (Reduction of Susceptibility Effect Using Frequency Modulation DANTE)

  • 정성택;홍인기;김지훈;노용만;조장희
    • 대한의용생체공학회:학술대회논문집
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    • 대한의용생체공학회 1995년도 추계학술대회
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    • pp.167-170
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    • 1995
  • An frequency modulated (FM) DANTE pulse sequence generates a quadratic phase toward the transverse of image by an FM RF pulse. In the image of a serious susceptibility effect, the phase due to the difference of the susceptibility in the pixel occurs susceptibility error which arise signal loss. But the signal loss due to the susceptibility effect in the pixel is reduced when the quadratic phase adds in the pixel. In this paper, we have generated a quadratic function toward the transverse (X-Y) using FM DANTE sequence and the susceptibility effect is reduced in the gradient echo (GE) imaging. Computer simulation and experimental results is obtained by using a whole-body KAIS 2.0T NMR system.

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Effects of Dietary Cellulose on the Basal Endogenous Loss of Phosphorus in Growing Pigs

  • Son, A.R.;Kim, B.G.
    • Asian-Australasian Journal of Animal Sciences
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    • 제28권3호
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    • pp.369-373
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    • 2015
  • An experiment was conducted to determine the effect of cellulose concentration in diets containing no phosphorus (P) on the basal endogenous loss (BEL) of P in growing pigs. Twelve barrows (an initial mean body weight = $49.6{\pm}3.2kg$) were individually housed in metabolism crates. Pigs were allotted to 4 experimental diets according to a cross-over design with 12 animals and 2 periods. Four P-free diets were mainly based on corn starch, sucrose, and gelatin, and were formulated to contain 0%, 4%, 8%, or 12% cellulose. Each period consisted of a 5-d adaptation and a 5-d collection period. The marker-to-marker method was used for fecal collection. The feed intake (p<0.05, linear and quadratic) and dry feces output (p<0.01, linear and quadratic) were increased with increasing dietary cellulose concentration. However, P concentration in the feces was decreased (p<0.01, linear and quadratic) with increasing dietary cellulose concentration. There was no significant difference in total P output and the BEL of P as mg per kg DMI (ranging from 157 to 214 mg/kg of dry matter intake) among experimental diets. However, values for the apparent total tract digestibility of energy, dry matter, organic matter, crude protein, and calcium were linearly decreased (p<0.01) with increasing cellulose concentration in the diet. In conclusion, dietary cellulose affected the amount of feces and digestibility of energy and nutrients, but did not affect the endogenous loss of P.

Optimal Estimation within Class of James-Stein Type Decision Rules on the Known Norm

  • Baek, Hoh Yoo
    • 통합자연과학논문집
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    • 제5권3호
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    • pp.186-189
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    • 2012
  • For the mean vector of a p-variate normal distribution ($p{\geq}3$), the optimal estimation within the class of James-Stein type decision rules under the quadratic loss are given when the underlying distribution is that of a variance mixture of normals and when the norm ${\parallel}\underline{{\theta}}{\parallel}$ in known. It also demonstrated that the optimal estimation within the class of Lindley type decision rules under the same loss when the underlying distribution is the previous type and the norm ${\parallel}{\theta}-\overline{\theta}\underline{1}{\parallel}$ with $\overline{\theta}=\frac{1}{p}\sum\limits_{i=1}^{n}{\theta}_i$ and $\underline{1}=(1,{\cdots},1)^{\prime}$ is known.

Multiclass Support Vector Machines with SCAD

  • Jung, Kang-Mo
    • Communications for Statistical Applications and Methods
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    • 제19권5호
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    • pp.655-662
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    • 2012
  • Classification is an important research field in pattern recognition with high-dimensional predictors. The support vector machine(SVM) is a penalized feature selector and classifier. It is based on the hinge loss function, the non-convex penalty function, and the smoothly clipped absolute deviation(SCAD) suggested by Fan and Li (2001). We developed the algorithm for the multiclass SVM with the SCAD penalty function using the local quadratic approximation. For multiclass problems we compared the performance of the SVM with the $L_1$, $L_2$ penalty functions and the developed method.

Fully Analog ECG Baseline Wander Tracking and Removal Circuitry using HPF Based R-peak Detection and Quadratic Interpolation

  • Nazari, Masoud;Rajeoni, Alireza Bagheri;Lee, Kye-Shin
    • Journal of Multimedia Information System
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    • 제7권3호
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    • pp.231-238
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    • 2020
  • This work presents a fully analog baseline wander tracking and removal circuitry using high-pass filter (HPF) based R-peak detection and quadratic interpolation that does not require digital post processing, thus suitable for compact and low power long-term ECG monitoring devices. The proposed method can effectively track and remove baseline wander in ECG waveforms corrupted by various motion artifacts, whereas minimizing the loss of essential features including the QRS-Complex. The key component for tracking the baseline wander is down sampling the moving average of the corrupted ECG waveform followed by quadratic interpolation, where the R-peak samples that distort the baseline tracking are excluded from the moving average by using a HPF based approach. The proposed circuit is designed using CMOS 0.18-㎛ technology (1.8V supply) with power consumption of 19.1 ㎼ and estimated area of 15.5 ㎟ using a 4th order HPF and quadratic interpolation. Results show SNR improvement of 10 dB after removing the baseline wander from the corrupted ECG waveform.

이차손실함수 하에서 최적 공정평균 및 규격하한 (Optimum Mean Value and Lower Limit under a Quadratic Loss Function)

  • 홍성훈;최성일;임훈;반재석
    • 품질경영학회지
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    • 제28권4호
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    • pp.194-203
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    • 2000
  • This paper is concerned with an economic selection of both the process mean and the lower limit for a continuous production process with the quadratic loss function. It is assumed that the quality characteristic is normally distributed with a known variability. A profit model is developed which involves selling price, production cost, reprocessing cost and the cost which is incurred by imperfect quality. Methods of finding optimum values of the process mean and the lower limit are presented, and a numerical example is given.

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