• 한국품질경영학회:학술대회논문집
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• 한국품질경영학회 1998년도 The 12th Asia Quality Management Symposium* Total Quality Management for Restoring Competitiveness
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• pp.198-207
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• 1998

The p chart approximate to the normal distribution has a difficulty to analyze the process condition precisely when the negative LCL is occurred. Furthermore, the probability of Type I error increases compared with using its original binomial distribution. For a long time the p chart has been used as approximated to the normal distribution because of its easy use. However, it becomes rapid and convenient to calculate the binomial distribution through the development of computer and software, so it is strongly suggested to use the binomial distribution determining control limits to reduce the probability of Type I error. In this study, I suggest that the control limits can be designed in use of binomial distribution and they can be utilized without special software by illustrating the certain work for establishing p-chart with the commercial one(EXCEL).

• 한국정보디스플레이학회:학술대회논문집
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• 한국정보디스플레이학회 2003년도 International Meeting on Information Display
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• pp.698-700
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• 2003

LGP (Light-Guide Panel) of TFT-LCD Backligh/Frontlight is one of the major components which affect on the product quality of LCD. Since the brightness distribution of LGP is sensitive to the process error in manufacturing, the optical characteristics such as reflection and absorption of LGP pattern should be modeled including the process error. LGP is developed by using the fast and reliable design technology, which uses the concept of the inverse-design, makes the model on the characteristics of uncertainty in the manufacturing process, and designs the dispersion pattern analytically without try-and-error by using an artificial intelligence. The PEA(Process-Error-Adaptive) design gives the best solution in handling the process error. The offset of target in feedback system makes such the best pattern design possible that the brightness distribution is nearly same (more than 90%) with target in regardless of the miscellaneous errors in mass production. The present design method has been also applied to frontlight and multi-side-lamp(eg., four-side-four-lamp) backlight.

• 한국산학기술학회논문지
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• 제22권5호
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• pp.561-566
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• 2021

오차분포 추정을 위한 커널 사이즈는 오차확률밀도 사이의 유클리드 거리를 최소화 알고리즘의 가중치 갱신에 적합한 커널 사이즈가 될 수 없다. 이 논문에서는 MED 알고리즘의 수렴 성능 향상을 위해 적응적으로 커널 사이즈를 갱신하는 방법을 제안하였다. 제안한 방식은 MED 학습 알고리즘의 가중치 갱신을 위해 커널 사이즈에 대한 오차분산의 평균변화율을 도입하여 MED의 오차에 대한 평균전력이 감소하는 방향으로 커널 사이즈를 조절하도록 하였다. 제안된 적응 커널 추정법을 무선통신 채널의 왜곡 보상에 적용하여 학습 성능을 실험하고 그 효능을 밝혔다. 오차분산에 비례한 작은 값을 가지는 기존의 오차분포 추정 위한 최적 커널 사이즈와 달리, 제안한 방법에 의한 커널 사이즈는 MED 가중치 수렴을 위한 적절한 커널 사이즈로 수렴함을 보였다. 실험 결과로부터 제안한 방법이 MED 알고리즘의 커널 사이즈 설정에 따른 민감성을 크게 해결한 방법이라고 볼 수 있다.

• 대한방사선기술학회지:방사선기술과학
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• 제42권2호
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• pp.137-143
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• 2019

The aim of this study was analyzed the setup error of breast cancer patients in intensity modulated radiation therapy(IMRT) with deep inspiration breath holding(DIBH) and was analyzed the dose distribution due to setup error. A total of 45 breast cancer cases were performed a retrospective clinical analysis of setup error. In addition, the re-treatment planning was carried by shifting the setup error from the isocenter at the treatment. Based on this, the dose distribution of PTV and OARs was compared and analyzed. The 3D error for small breast group and medium breast group and large breast group were 3.1 mm and 3.7 mm and 4.1 mm, respectively. The difference between the groups was statistically significant(P=0.003). DVH results showed HI, CI for the PTV difference between standard treatment plan and re-treatment plan of 14.4%, 4%. The difference in $D_5$ and $V_{20}$ of the ipsilateral lung was 5.6%, 13% respectively. The difference in $D_5$ and $V_5$ of the heart of right breast cancer patients was 6.8%, 8% respectively. The difference in $D_5$, $V_{20}$ of the heart of left breast cancer patients was 7.2%, 23.5% respectively. In this study, there was a significant association between breast size and significant setup error in breast cancer patients with DIBH. In addition, it was found that the dose distribution of the PTV and OARs varied according to the setup error.

• 대한방사선치료학회지
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• 제16권2호
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• pp.81-89
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• 2004

목적 : 방사선 치료에서 환자와 근무자에 의한 setup error등은 치료성적이 결정될 수 있는 중요한 요인이라고 볼 수 있다. 이에 환자와 근무자에 의한 SET-UP ERROR가 환자치료에 미치는 영향에 대하여 비교 분석하고자 한다. 대상 및 방법 : 실험은 human phantom을 이용하여 C-T scan시 Left방향의 Lateral Level을 0mm, 3mm, 5mm, 7mm, 10mm, 15mm, 20mm로 변화시켜 SET-UP ERROR를 유발하였고, 각각에 대하여 C-T scan을 시행하였고, SET-UP ERROR가 유발된 각각의 C-T image를 얻어 RTP장비를 이용하여 임상에서 많이 사용되는 plan을 사용하여 7개의 C-T image에 각각의 plan-대향이문조사plan, Box-4문조사plan, 3Dimension plan-3개를 시행하여 총 21개의 plan을 실시하였다. (CTV+1cm margin, CTV+0.5cm margin, CTV+0.3cm margin = PTV) 이렇게 얻어진 plan을 이용하여 SET-UP ERROR가 유발이 안된 0mm image의 plan 3개와 SET-UP ERROR가 있는 6개 image의 총 18개의 plan을 대향이문조사plan, Box4문조사plan, 3Dimension plan으로 나누어 선량분포와 DVH를 이용하여 비교 분석하였다. 결과 : SET-UP ERROR를 유발시킨 3mm, 5mm, 7mm C-T image에서는 대향이문조사plan을 제외하고는 모든 plan에서 충분히 치료에 영향을 미칠만한 변화가 나타났으며, Box4문조사plan에서는 SET-UP ERROR에 의한 CTV가 Field 밖으로 빠짐으로 선량분포와 DVH가 나빠지는 현상이 나타났다. 결론 : 환자의 움직임, CTV 3차원형태, CTV margin등이 치료에 영향을 미친다. 이러한 영향을 줄이기 위해서는 환자의 긴장감과 움직임을 줄일 수 있는 환자교육과 정확한 환자setup능력이 치료의 승패를 좌우한다고 생각된다. 또한 재현성과 움직임을 줄일 수 있는 accessory 개발과 보급이 중요하다.

• Communications for Statistical Applications and Methods
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• 제14권1호
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• pp.33-55
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• 2007

The economic world is full of patterns, many of which exert a profound influence over society and business. One of the most contentious is the distribution of wealth. Way back in 1897, an Italian engineer-turned-economist named Vilfredo Pareto discovered a pattern in the distribution of wealth that appears to be every bit as universal as the laws of thermodynamics or chemistry. The present paper proposes some Bayes estimators of shape parameter of Pareto income distribution in censored sampling. Asymmetric LINEX loss function has been considered to study the effects of overestimation and underestimation. For the prior distribution of the parameter involved a number of priors including one and two-parameter exponential, truncated Erlang and doubly truncated gamma have been contemplated to express the belief of the experimenter s/he has regarding the parameter. The estimators thus obtained have been compared theoretically and empirically with the corresponding estimators under squared error loss function, some of which were reported by Bhattacharya et al. (1999).

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 2006년도 춘계공동학술대회 논문집
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• pp.1677-1683
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• 2006

Color image segmentation is useful for fast retrieval in large image database. For that purpose, new image segmentation technique based on the probability of pixel distribution in the image is proposed. Color image is first divided into R, G, and B channel images. Then, pixel distribution from each of channel image is extracted to select to which it is similar among the well known probabilistic distribution function-Weibull, Exponential, Beta, Gamma, Normal, and Uniform. We use sum of least square error to measure of the quality how well an image is fitted to distribution. That P.d.f has minimum score in relation to sum of square error is chosen. Next, each image is quantized into 4 gray levels by applying thresholds to the c.d.f of the selected distribution of each channel. Finally, three quantized images are combined into one color image to obtain final segmentation result. To show the validity of the proposed method, experiments on some images are performed.

• Geomechanics and Engineering
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• 제35권5호
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• pp.499-509
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• 2023

The objective of this study is to perform outlier analysis to obtain the distribution of groundwater levels through the best model. The groundwater levels are measured in 10, 25 and 30 piezometers in Seoul, Daejeon and Suncheon in South Korea. Fifty-eight empirical distribution functions were applied to determine a suitable fit for the measured groundwater levels. The best fitted models based on the measured values are determined as the Generalized Pareto distribution, the Johnson SB distribution and the Normal distribution for Seoul, Daejeon and Suncheon, respectively; the reliability is estimated through the Anderson-Darling method. In this study, to choose the appropriate confidence interval, the relationship between the amount of outlier data and the confidence level is demonstrated, and then the 95% is selected at a reasonable confidence level. The best model shows a smaller error ratio than the GEV while the Mahalanobis distance and outlier labelling methods results are compared and validated. The outlier labelling and Mahalanobis distance based on median shown higher validated error ratios compared to their mean equivalent suggesting, the methods sensitivity to data structure.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2008년도 하계종합학술대회
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• pp.1085-1086
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• 2008

An error prediction system (EPS) for a power distribution system can predict an out-of-order state based on gathered data from the system. This paper describes a software structure of an EPS that is equipped with various sensors. The software analyzes the gathered data from sensors and predict error symptoms using statistical methods. The EPS system is installed on a real power distribution system.

• 한국통신학회논문지
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• 제19권7호
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• pp.1224-1233
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• 1994

업링크와 다운링크 경로상에 각각 가산성 백색 가우스잡음이 존재하는 이동 위성 통신로에서 TWTA의 비성형성에 의한 BPSK신호와 QPSK신호의 오율성능을 조사하였따. 다운링크 경로상의 페이딩은 Rice분포를 한다고 가정하였다. Rice 분포에 대한 근사 이산 확률분포를 고전적인 모멘트 기법(CMT)을 이용하여 처음으로 유도하였다. 최종적으로 오율은 근사 이산 확률 분포와 Gauss Quadrature Formula를 이용하여 계산하였다.