• Title/Summary/Keyword: shift parameter

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Phase Shift Analysis of 6Li Elastic Scattering on 12C and 28Si at Elab = 318 MeV

  • Kim, Yong Joo
    • New Physics: Sae Mulli
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    • v.68 no.12
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    • pp.1331-1337
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    • 2018
  • We present a three-parameter phase shift model whose form is the same as that of Coulombmodified Glauber model obtained from Gaussian nuclear densities. This model is applied to the $^6Li+^{12}C$ and the $^6Li+^{28}Si$ elastic scatterings at $E_{lab}=318MeV$. The calculated differential cross sections provide quite a satisfactory account of the experimental data. The diffractive oscillatory structures observed at forward angles can be explained as being due to the strong interference between the near-side and the far-side scattering amplitudes. The optical potentials for two systems are predicted by using the method of inversion. The calculated inversion potentials are found to be in fairly good agreements with the results determined from the optical model analysis in the surface regions around the strong absorption radius. We also investigate the effects of parameters in the three-parameter phase shift model on the elastic scattering cross sections.

Monitoring the asymmetry parameter of a skew-normal distribution

  • Hyun Jun Kim;Jaeheon Lee
    • Communications for Statistical Applications and Methods
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    • v.31 no.1
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    • pp.129-142
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    • 2024
  • In various industries, especially manufacturing and chemical industries, it is often observed that the distribution of a specific process, initially having followed a normal distribution, becomes skewed as a result of unexpected causes. That is, a process deviates from a normal distribution and becomes a skewed distribution. The skew-normal (SN) distribution is one of the most employed models to characterize such processes. The shape of this distribution is determined by the asymmetry parameter. When this parameter is set to zero, the distribution is equal to the normal distribution. Moreover, when there is a shift in the asymmetry parameter, the mean and variance of a SN distribution shift accordingly. In this paper, we propose procedures for monitoring the asymmetry parameter, based on the statistic derived from the noncentral t-distribution. After applying the statistic to Shewhart and the exponentially weighted moving average (EWMA) charts, we evaluate the performance of the proposed procedures and compare it with previously studied procedures based on other skewness statistics.

Experimental Study of Chemical Shift Artifacts at 1.5T and 3.0T MRI using Gradient Echo Pulse Sequence (GE 펄스시퀀스을 이용한 1.5T와 3.0T MRI의 화학적 이동 인공물의 실험적 연구)

  • Cheol, Kweon Dae
    • Journal of the Korean Society of Radiology
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    • v.10 no.7
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    • pp.531-537
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    • 2016
  • An experimental study was to use the parameter to determine the MRI artifact of chemical shift that occurs in water and fats. Scanning the image according to the encoding parameter and the bandwidth and change in 1.5T and 3.0T MRI to the SNR, we compared the CNR. In the image was confirmed that the occurrence of artefacts in the chemical shift of the water and oil. 3.0T more image artifacts in the 1.5T was confirmed that the relatively reduced. The width of the bandwidth it could be confirmed that according to the honeycombs artifacts decrease. Therefore, in order to reduce the artifacts in the MRI scan of the chemical shift runners weak field strength, is thought to be appropriate to widen the width of the bandwidth.

Optimal Design of a EWMA Chart to Monitor the Normal Process Mean

  • Lee, Jae-Heon
    • The Korean Journal of Applied Statistics
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    • v.25 no.3
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    • pp.465-470
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    • 2012
  • EWMA(exponentially weighted moving average) charts and CUSUM(cumulative sum) charts are very effective to detect small shifts in the process mean. These charts have some control-chart parameters that allow the charts and be tuned and be more sensitive to certain shifts. The EWMA chart requires users to specify the value of a smoothing parameter, which can also be designed for the size of the mean shift. However, the size of the mean shift that occurs in applications is usually unknown and EWMA charts can perform poorly when the actual size of the mean shift is significantly different from the assumed size. In this paper, we propose the design procedure to find the optimal smoothing parameter of the EWMA chart when the size of the mean shift is unknown.

An Edge Preserving Color Image Segmentation Using Mean Shift Algorithm and Region Merging Method (Mean Shift 알고리즘과 영역 병합 방법을 이용한 경계선 보존 컬러 영상 분할)

  • Kwak Nae-Joung;Kwon Dong-Jin;Kim Young-Gil
    • The Journal of the Korea Contents Association
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    • v.6 no.9
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    • pp.19-27
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    • 2006
  • Mean shift procedure is applied for the data points in the joint spatial-range domain and achieves a high quality. However, a color image is segmented differently according to the inputted spatial parameter or range parameter and the demerit is that the image is broken into many small regions in case of the small parameter. In this paper, to improve this demerit, we propose the method that groups similar regions using region merging method for over-segmented images. The proposed method converts a over-segmented image in RGB color space into in HSI color space and merges similar regions by hue information. Here, to preserve edge information, the region merge constraints are used to decide whether regions are merged or not. After then, we merge the regions in RGB color space for non-processed regions in HSI color space. Experimental results show the superiority in region's segmentation results.

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Substituted Phenyl 2-Thiophenecarboxylates and Benzoates:Synthesis, NMR Spectra, and Aromaticity Index

  • Lee, Chang Gyu;Yu, Ji Suk;Park, Jong Seok
    • Bulletin of the Korean Chemical Society
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    • v.21 no.1
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    • pp.49-55
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    • 2000
  • A series of m-, and p-substituted phenyl 2-thiophenecarboxylates and benzoates was prepared by the reaction of the corresponding acyl chlorides and phenols. Their $^1H$ and $^{13}C$ NMR chemical shifts were analyzed using single substituent parameter (S SP) and dual substituent parameter (DSP) methods. The relative aromaticity index of thiophene was estimated to be 0.92 from the plot of the chemical shift of the carbonyl carbons of the thienoyl esters against chemical shift of the carbonyl carbons of the benzoyl esters.

Shifted Linear Interpolation with an Image-Dependent Parameter (영상에 종속적인 매개변수를 갖는 이동 선형 보간법)

  • Park, Do-Young;Yoo, Hoon
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.17 no.10
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    • pp.2425-2430
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    • 2013
  • This paper presents an shifted linear interpolation method with an image-dependent parameter. The previous shifted linear interpolation proposed the optimal shift parameter of 0.21, which is calculated by spectrum analysis of the shifted linear interpolation kernel. However, the parameter can be different if we takes an input image spectrum into account. Thus, we introduce an image-dependent parameter. An experiment shows the best shift parameter is 0.19 in average for real images. Also, simulation results indicate the proposed method is superior to the existing shifted linear interpolation as well as conventional methods such as linear interpolation and cubic convolution interpolation in terms of the subjective and objective image quality.

A Color Image Segmentation Using Mean Shift and Region merging method (Mean Shift와 영역병합을 이용한 칼라 영상 분할)

  • Kwak, Nae-Joung;Kwon, Dong-Jin;Kim, Young-Gil
    • Proceedings of the Korea Contents Association Conference
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    • 2006.05a
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    • pp.401-404
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    • 2006
  • Mean shift procedure is applied for the data points in the joint spatial-range domain and achieves a high quality. However, a color image is segmented differently according to the inputted spatial parameter or range parameter and the demerit is that the image is broken into many small regions in case of the small parameter. In this paper, to improve this demerit, we propose the method that groups similar regions using region merging method for over-segmented images. The proposed method converts a over-segmented image in RGB color space into in HSI color space and merges similar regions by hue information. Here, to preserve edge information, the proposed method use by merging constraints to decide whether regions is merged or not. After then, we merge the regions in RGB color space for non-processed regions in HSI color space. Experimental results show the superiority in region's segmentation results.

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Shift-Power Transformation (이동-멱변환에 관한 연구)

  • Cho Ki-Jong;Jeong Seok-Oh;Shin Key-Il
    • The Korean Journal of Applied Statistics
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    • v.19 no.2
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    • pp.283-290
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    • 2006
  • Generally speaking, power transformations such as Box-Cox transformation(1964) is applied for variance stabilization and symmetry. But, when the distribution of the original data has a large mean with a small variance or the coefficient of variation is very small, they don't work at all. This paper propose a simple method to introduce a shift parameter before applying power transformations and showed the numerical evidence by Monte Carlo simulation and a real data analysis.

Optimal Design of c Control Chart using Variable Sampling Interval (가변추출간격을 이용한 c 관리도의 최적설계)

  • Park, Joo-Young
    • Journal of the Korea Safety Management & Science
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    • v.9 no.2
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    • pp.215-233
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    • 2007
  • Even though the ad hoc Shewhart methods remain controversial due to various mathematical flaws, there is little disagreement among researchers and practitioners when a set of process data has a skewness distribution. In the context and language of process control, the error related to the process data shows that time to signal increases when a control parameter shifts to a skewness direction. In real-world industrial settings, however, quality practitioners often need to consider a skewness distribution. To address this situation, we developed an enhanced design method to utilize advantages of the traditional attribute control chart and to overcome its associated shortcomings. The proposed design method minimizes bias, i.e., an average time to signal for the shift of process from the target value (ATS) curve, as well as it applies a variable sampling interval (VSI) method to an attribute control chart for detecting a process shift efficiently. The results of the factorial experiment obtained by various parameter circumstances show that the VSI c control chart using nearly unbiased ATS design provides the smallest decreasing rate in ATS among other charts for all experimental cases.