• Journal of the Korean Data and Information Science Society
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• 제19권4호
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• pp.1173-1181
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• 2008

In this paper, when the parameter of interest is the shape parameter in Pareto distribution, we develop likelihood based inference for this parameter. Specially, we develop signed log-likelihood ratio statistic and the modified signed log-likelihood ratio statistic for the shape parameter. It is well-known that as sample size grows, the modified signed log-likelihood ratio statistic converges to standard normal distribution faster than the signed log-likelihood ratio statistic. But the computation of the modified signed log-likelihood statistic is hard or even impossible when the sufficient statistics and the ancillary statistics are not clear. In this case, one can consider an approximation to the modified signed log-likelihood statistic. Specially, when the parameter of interest is informationally orthogonal to the nuisance parameters, we propose the approximate modified signed log-likelihood statistic. Through simulation, we investigate the performances of the proposed statistics with the signed log-likelihood statistic.

• 산업경영시스템학회지
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• 제21권45호
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• pp.201-213
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• 1998

We address the problem of choosing the most economic mean value for an automatic filling operation on a production line through the sampling inspection. If quality characteristic of a unit is less than inspection specification then the goods is not accepted. Otherwise, it is accepted. The lots that the numbers of non-conforming units in a sample are larger than the allowable number of non-conforming units are rejected. The non-conforming units in the rejected lots are separated by the screening inspection. The non-conforming units separated are sold in discount price. We assume that quality characteristic is larger-the-better characteristic, the distribution of quality characteristic is normal distribution, and the standard deviation of the distribution is known. This paper presents total expected profit function model considering sales revenue, inspection costs, and material costs. The manufacturing process mean value maximizing total expected profit is determined, and the results of the process target value and total expected profit is analyzed as coefficients change.

• 한국멀티미디어학회논문지
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• 제10권5호
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• pp.679-686
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• 2007

매년 게임업체의 수는 증가하고 있으나 이들 업체에 의하여 개발 및 유통되는 모든 게임들이 경쟁력을 갖고 있는 것은 아니다. 하나의 게임 나아가서는 게임산업의 경쟁력과 부가가치를 높이기 위하여 수요자들의 만족도가 높은 게임을 개발해야 하며 이를 위하여 만족도가 어느 정도 되는지를 평가할 수 있는 과학적 연구가 필요하다. 본 논문에서는 AHP와 통계적 방법을 이용하여 게임 만족도를 정량적으로 추정하고 만족도 점수의 분포를 구하는 방법을 연구하였다. 이 방법을 활용하여 기존 또는 향후 개발되는 게임들의 만족도 수준과 기준을 예측할 수 있는 기대효과를 얻을 수 있다.

• 응용통계연구
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• 제21권6호
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• pp.901-910
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• 2008

국내 삼일열 말라리아는 1990년대 중반부터 급격히 증가하여 2000년대에는 연평균 1600여명이 발병하고 있다. 본 연구에서는 이미 알려진 잠복기 분포와 2001년부터 2006년까지의 발병자수 자료에 바탕하여 후향연산식을 활용하여 국내 삼일열 말라리아의 감염분포를 최소제곱법으로 추정하였다. 추정된 감염분포는 평균이 207일이고 표준편차가 30.7일인 정규분포를 이루었다. 이를 이용하여 연간 유병자수 분포를 산출한 결과, 말라리아의 하루 평균 유병자수는 628.8명 이었다.

• 응용통계연구
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• 제26권1호
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• pp.37-47
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• 2013

Q-Q 플롯은 자료에 대한 분포적 가정을 평가하기 위해서 사용되는 편리하고 효과적인 그래프 방법이다. Q-Q 플롯은 자료의 분포와 이론적 분포를 비교하기 위한 확률플롯으로 자료에서의 분위수와 이에 대응하는 이론적 분위수를 각각 수직축과 수평축으로 해서 그린 산점도의 형태를 취한다. 본 논문에서는 확률변수 X가 위치모수 ${\mu}$와 척도수 ${\lambda}$를 가지는 역가우스분포를 따르면, 변환된 확률변수 $Y={\mid}\sqrt{\lambda}(X-{\mu})/{\mu}\sqrt{X}{\mid}$는 평균이 0이고 분산이 1인 표준반접정규분포를 하게 되는 분포적 결과를 활용하여 역가우스분포 Q-Q 플롯의 구축방법을 소개한다. 역가우스분포와 다른 분포를 따르는 자료를 대상으로 그린 Q-Q 플롯에서 나타나는 점들의 형태를 알아보고자 모의실험을 수행하고 그 결과를 제시한다. 실제 자료에 대한 사례분석을 통해 제안한 Q-Q 플롯의 유용성을 보인다.

• 품질경영학회지
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• 제51권4호
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• pp.663-675
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• 2023

Purpose: Skewness is an indicator used to measure the asymmetry of data distribution. In the past, product quality was judged only by mean and variance, but in modern management and manufacturing environments, various factors and volatility must be considered. Therefore, skewness helps accurately understand the shape of data distribution and identify outliers or problems, and skewness can be utilized from this new perspective. Therefore, we would like to propose a statistical quality control method using skewness. Methods: In order to generate data with the same mean and variance but different skewness, data was generated using normal distribution and gamma distribution. Using Minitab 18, we created 20 sets of 1,000 random data of normal distribution and gamma distribution. Using this data, it was proven that the process state can be sensitively identified by using skewness. Results: As a result of the analysis of this study, if the skewness is within ± 0.2, there is no difference in judgment from management based on the probability of errors that can be made in the management state as discussed in quality control. However, if the skewness exceeds ±0.2, the control chart considering only the standard deviation determines that it is in control, but it can be seen that the data is out of control. Conclusion: By using skewness in process management, the ability to evaluate data quality is improved and the ability to detect abnormal signals is excellent. By using this, process improvement and process non-sub-stitutability issues can be quickly identified and improved.

• Nuclear Engineering and Technology
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• 제53권1호
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• pp.93-102
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• 2021

The analysis of the fluid flow characteristics in reactor pressure vessel is an important part of the hydraulic design of nuclear power plant, which is related to the structure design of reactor internals, the flow distribution at core inlet and the safety of nuclear power plant. The flow distribution and mixing characteristics in the pressurized reactor vessel for the 1000MWe advanced pressurized water reactor is analyzed by using Computational Fluid Dynamics (CFD) method in this study. The geometry model of the full-scaled reactor vessel is built, which includes the cold and hot legs, downcomer, lower plenum, core, upper plenum, top plenum, and is verified with some parameters in DCD. Under normal condition, it is found that the flow skirt, core plate holes and outlet pipe cause pressure loss. The maximum and minimum flow coefficient is 1.028 and 0.961 respectively, and the standard deviation is 0.019. Compared with other reactor type, it shows relatively uniform of the flow distribution at the core inlet. The coolant mixing coefficient is investigated with adding additional variables, showing that mass transfer of coolant occurs near the interface. The coolant mainly distributes in the 90° area of the corresponding core inlet, and mixes at the interface with the coolant from the adjacent cold leg. 0.1% of corresponding coolant is still distributed at the inlet of the outer-ring components, indicating wide range of mixing coefficient distribution.

• 한국의류산업학회지
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• 제1권2호
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• pp.137-147
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• 1999

The purpose of this study was to classify female students' somatotypes, to investigate the relationship between five somatotypes obtained from anthropometric measurements and to examine the relationship between the spinal deformity and somatotypes. The subjects for anthropometric measurements were 844 female middle and high school students. The data were analyzed by cluster analysis, correspondence analysis, Duncan test, and T-test. The results were as follows. Cluster analysis on the factors extracted from directly measured items classified subjects into five types (middle height and a little slim type (39.6%), low height and a little slim type (13.1%), middle height and a little fat type (18.0%), tall and very fat type (7.7%), and very tall and standard type (21.6%). In examining the relationship between the normal people and those of the spinal deformity, the normal showed higher mean value in almost all the items of the girth, the depth, and the length. High school students had more spinal deformity in number than middle school students. The degree of deformity was higher in the right spinal deformity than in the left spinal deformity as the age increased. In terms of the distribution of the spinal deformity classified by the somatotype, Type 1 (middle height and a little slim type) and Type 5 (very tall and standard type) appeared the highest.

• 대한한의학회지
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• 제38권4호
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• pp.55-61
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• 2017

Objectives: In order to accurately measure skin moisture and accumulate normal skin moisture data, analyzing the uncertainty of the skin moisture measurement and establishing standard reference data is essential. It helps to evaluate the skin's condition and has great significance in diagnosis and treatment. In this study, the traceability of the equipment and the uncertainty of the results were analyzed for their potential use in the field of Korean medicine. The data was collected measuring skin moisture on the sole of the foot. Methods: One professional measured the moisture of the adult male's foot 10 times following a determined protocol. The standard uncertainty of repeated measurements was calculated from the mean value of 10 repeated measurements. Ten trainee participants also measured the adult male's foot following a determined protocol. The standard uncertainty by tester was calculated from the value of repeated measurements. Results: As a result of analyzing the difference between the mean and standard uncertainties in both the expert and trainees, it was confirmed that the variance in this study did not satisfy the normal distribution. In addition, the Mann-Whitney U-test was carried out, and it was found that there was no significant difference in the measured values of the two groups. The authorized uncertainty of measurements and traceability of all the equipment was not confirmed. Conclusions: This paper establishes the basis for later measurement-equipment research to provide the objective indicators to approach the dryness of plantar skin from dehydration, the Korean medicine perspective.

• 한국동물위생학회지
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• 제43권3호
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• pp.161-165
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• 2020

In order to effective treats a sick calf, it is necessary to obtain accurate information about the patient's condition. However, the standard references for Korean cattle claves are not well known. Therefore, this study aims to present useful clinical values by analyzing normal blood and diarrhea blood of Hanwoo calf. Recently, with the advent of a portable blood analyzer, it is possible to immediately analyze the patient's condition and severity in the field, not in the laboratory, and to calculate a suitable dosage for supporting fluid therapy. Therefore, in this study, the distribution of red blood cells (RBC) and white blood cells (WBC) were analyzed in normal and diarrhea Hanwoo calves. As a result, Hematocrit (HCT) levels increase significantly between 1 and 20 days in diarrhea positive calves. Changes in leukocyte composition had similar growth patterns in normal and diarrhea calves. As it grew, the proportion of neutrophils decreased and lymphocytes increased. However, the number of WBCs increased from 1 to 10 and 21 to 30 days in diarrhea positive calves, which is closely related to the increase in neutrophils. Therefore, those data can be used for diagnosis and treatment of diarrhea calf.