폐쇄성 비후성심근증과 심실중격비후를 가진 고혈압성심장병에서의 심전도학적 차이

박창순,김유홍,박정대,장성국,박의현,이형우,채성철,전재은,박희명 대한순환기학회 1988 Korean Circulation Journal Vol.18 No.4

Economic design of an integrated process control procedure with repeated adjustments and EWMA monitoring

박창순,Marion R. Reynolds Jr. 한국통계학회 2008 Journal of the Korean Statistical Society Vol.37 No.2

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A minimum asymptotic mean squared error controller for an IMA(1, 1) noise process with a starting offset, and its resetting design

박창순 한국통계학회 2011 Journal of the Korean Statistical Society Vol.40 No.3

In a discrete-part manufacturing process, the noise is often described by an IMA(1, 1)process and the pure unit delay transfer function is used as the feedback controller to adjust it. The optimal controller for this process is the well-known minimum mean square error (MMSE) controller. The starting level of the IMA(1, 1) model is assumed to be on target when it starts. Considering such an impractical assumption, we adopt the starting offset. Since the starting offset is not observable, the MMSE controller does not exist. An alternative to the MMSE controller is the minimum asymptotic mean square error controller, which makes the long-run mean square error minimum. Another concern in this article is the un-stability of the controller, which may produce high adjustment costs and/or may exceed the physical bounds of the process adjustment. These practical barriers will prevent the controller to adjust the process properly. To avoid this dilemma, a resetting design is proposed. That is, the resetting procedure in use of the controller is to adjust the process according to the controller when it remains within the reset limit, and to reset the process, otherwise. The total cost for the manufacturing process is affected by the off-target cost, the adjustment cost, and the reset cost. Proper values for the reset limit are selected to minimize the average cost per reset interval (ACR) considering various process parameters and cost parameters. A time non-homogeneous Markov chain approach is used for calculating the ACR. The effect of adopting the starting offset is also studied here.

An Integrated Process Control Procedure with Repeated Adjustments and EWMA Monitoring under an IMA(1,1) Disturbance with a Step Shift

박창순 한국통계학회 2004 Journal of the Korean Statistical Society Vol.33 No.4

Statistical process control (SPC) and engineering process control (EPC) are based on dierent strategies for process quality improvement. SPC reduces process variability by detecting and eliminating special causes of process variation, while EPC reduces process variability by adjusting compensatory variables to keep the quality variable close to target. Recently there has been need for an integrated process control (IPC) procedure which combines the two strategies. This paper considers a scheme that simultaneously applies SPC and EPC techniques to reduce the variation of a process. The process model under consideration is an IMA(1,1) model with a step shift. The EPC part of the scheme adjusts the process, while the SPC part of the scheme detects the occurrence of a special cause. For adjusting the process repeated adjustment is applied according to the predicted deviation from target. For detecting special causes the exponentially weighted moving average control chart is applied to the observed deviations. It was assumed that the adjustment under the presence of a special cause may increase the process variability or change the system gain. Reasonable choices of parameters for the IPC procedure are considered in the context of the mean squared deviation as well as the average run length.

Monitoring of Gene Regulations Using Average Rankin DNA Microarray: Implementation of R

박창순 한국데이터정보과학회 2007 한국데이터정보과학회지 Vol.18 No.4

Traditional procedures for DNA microarray data analysis are to preprocess and normalize the gene expression data, and then to analyze the normalized data using statistical tests. Drawbacks of the traditional methods are: genuine biological signal may be unwillingly eliminated together with artifacts, the limited number of arrays per gene make statistical tests difficult to use the normality assumption or nonparametric method, and genes are tested independently without consideration of interrelationships among genes. A novel method using average rank in each array is proposed to eliminate such drawbacks. This average rank method monitors differentially regulated genes among genetically different groups and the selected genes are somewhat different from those selected by traditional P-value method. Addition of genes selected by the average rank method to the traditional method will provide better understanding of genetic differences of groups.

도금공정에서 최소기대손실을 위한 목표치의 설정

박창순,김정준,Park, Chang-soon,Kim, Jung-Jun 한국데이터정보과학회 2010 한국데이터정보과학회지 Vol.21 No.6

도금공정에서는 도금두께의 규격한계는 주어지지만 대부분의 경우 목표치는 주어지지 않는다. 목표치가 주어지지 않았을 때 일반적으로 규격의 중심점이 목표치로 사용된다. 하지만 공정능력치가 크다면 규격의 중심을 목표치로 사용하는 것은 총 손실비용면에서 최선의 선택이 아니다. 이 논문에서는 총 손실비용을 생산비용과 손실함수의 합으로 정의하였고 기대 총 손실비용을 최소화 하는 목표치를 제안하였다. 그리고 그때의 공정능력치의 감소가 미미한 것을 보였다. In the plating process of the IC chips for the printed circuit board manufacturing, specification limits for the plating thickness are usually given but its target is not specified in most cases. When the target is not specified, the center point of the specification limits is used instead. When the process capability is large, however, the use of the center point for the target is not the best choice in the context of the total cost. In this paper, the total cost is defined in terms of the production cost and the loss function, and then the optimal choice for target is studied in order to minimize the expected loss. As a consequence, the optimal choice of the target reduces the expected loss significantly, while reducing the process capability slightly.

미세 구조 변화에 따른 ZnS 세라믹의 중적외선 투과 특성 연구

박창순,여서영,권태형,박운익,윤지선,정영훈,홍연우,조정호,백종후,Park, Chang-Sun,Yeo, Seo-Yeong,Kwon, Tae-Hyeong,Park, Woon-ik,Yun, Ji-Sun,Jeong, Young-Hun,Hong, Youn-Woo,Cho, Jeong-Ho,Paik, Jong-Hoo 한국전기전자재료학회 2017 전기전자재료학회논문지 Vol.30 No.11

Transparent ZnS ceramics were synthesized by hydrothermal synthesis ($180^{\circ}C$ for 70 h), and were sintered by a hot press process at $950^{\circ}C$. To confirm the optical properties of the ZnS ceramics after sintering for various sintering holding times, we performed X-ray diffraction analysis, scanning electron microscopy, and Fourier-transform-infrared spectroscopy. The ZnS nanopowders was found to be single-phase (cubic) without any hexagonal phase. However, the hexagonal phase is formed and increases in content with increasing sintering holding time. The density of the ZnS ceramics was above 99.7%, except for the unsintered one. The ZnS ceramics showed high transmittance (~70%) when sintered for more than 2 h.

산업용지 생산을 위한 UKP 중요 특성 선정과 분석 : 섬유의 화학적 특성과 산업용지 특성과의 관계

박창순,박종문,채희재,임종혁 한국펄프·종이공학회 2009 한국펄프·종이공학회 학술발표논문집 Vol.2009 No.10

편차제곱평균과 수정량분산의 균형을 위한 단일 및 이중 지수가중이동평균 피드백 수정기의 수정

박창순,권성구,Park, Chang-Soon,Kwon, Sung-Gu 한국데이터정보과학회 2009 한국데이터정보과학회지 Vol.20 No.1

수정절차에서 공정수정기는 잡음이 존재하지만 제거할 수 없을 때 공정수준을 목표치에 가깝게 수정하는데 종종 유용하게 사용된다. 강건 수정기의 예로는 단일 및 이중 지수가중이동평균 수정기가 있다. 이중 지수가중이동평균 수정기는 단일 지수가중이동평균 수정기가 제거할 수 없는 공정편차의 치우침을 줄일 수 있도록 고안되었다. 이 논문에서는 이 두 가지 수정기가 적용될 때 과도하게 커질 수 있는 수정량분산을 줄일 수 있도록 원래의 수정기에 지수가중이동평균을 적용함으로써 수정되었다. 주어지 수정기에 대한 지수가중이동평균 수정은 편차제곱평균은 조금 증가시키지만, 수정량분산을 줄이는데 성공적임을 보이고 있다. The process controller in the adjustment procedure is often used effectively to control the process level close to target when noise is present and unremovable. Examples of the robust controller are single EWMA controller and double EWMA controller. Double EWMA controller is designed to reduce the offset of the process deviation, which single EWMA can not eliminate. In this paper, the two controllers are modified by taking EWMA of the original controller to reduce the adjustment variance, which may become excessively large when the two given controllers are implemented. It is shown that the EWMA modification of the given controllers is successful in reducing the adjustment variance, while the mean squared deviation increases slightly.

지수가중이동평균관리도의 경제적 최적모수의 선정

박창순,원태연 한국통계학회 1996 응용통계연구 Vol.9 No.1

지수가중이동평균관리도는 최근 들어 공정검색과 공정수정에 널리 이용되고 있으나 모수의 설정에 관한 연구는 많지 않다. 관리도의 설계는 통계적 설계와 경제적 설계로 분류한다. 통계적 설계는 허용된 제1종 오류하에서 제2종 오류를 최소화하는데 반해 경제적 설계는 공정에서 발생하는 모든 가능한 비용을 고려한 비용함수를 최소화한다. 이 논문에서는 지수가중이동평균관리도의 통계적 설계와 함께 경제적 설계를 정의한 다음 각 설계에서의 최적모수를 선정하여 결과를 비교한다. 경제적 설계에서 설정된 최적모수는 통계적 설계와 다르게 나타남을 알 수 있고 특히 가중치의 값은 통계적 설계에서 보다 항상 큰 값으로 나타난다. 경제적 설계에서는 고려하는 이상원인의 수에 따라 단일이상원인과 다중이상원인 모형으로 구분하여 설계한다. 다중이상원인의 평균적 개념으로 적용되는 단일이상원인 모형에서는 실제 다중이상원인이 존재할 때에 잘못된 판단을 할 수 있음을 보이고 있다. Exponentially weighted moving averae(EWMA) control chart has been used widely for process monitoring and process adjustment recently, but there has not been many studies about the selection of the parameters. Design of the control chart can be classified into the statistical design and the economic design. The purpose of the economic design is to minimize the cost function in which all the possible costs occurring during the process are probability given the Type I error probability. In this paper the optimal parameters of the EWMA chart are selected for the economic design as well as for the statistical design. The optimal parameters for the economic design show significantly different from those of the statistical design, and especially the weight is always larger than that used in the statistical design. In the economic design, we divide the model into the single assignable cause model and the multiple assignable causes model caacording to number of which is used as the average context of the multiple assignable causes, it shows that the selection of the parameters may be misleading when the multiple assignable causes exist in practice.