• 제목/요약/키워드: Pre-control Chart

검색결과 13건 처리시간 0.032초

Lean 생산방식에 적합한 Complex Target & Pre-Control Chart 적용방안 연구;동일 허용공차를 생산하는 다품종 소량생산을 중심으로 (A Study on the Complex Target & Pre-Control Chart Apply to Lean Production)

  • 신흥섭;이상복
    • 한국품질경영학회:학술대회논문집
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    • 한국품질경영학회 2007년도 춘계학술대회
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    • pp.187-195
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    • 2007
  • 최근 우리나라에서 도요타를 벤치마킹하여 TPS를 도입하는 회사가 늘어나고 있다. 다품종 소량생산의 Lean 생산방식을 적용하기 위해서는 셋업시간의 단축 뿐만 아니라 이에 따른 셋업 품질능력이 향상되어야 한다. 따라서, 공정을 셋업하는 작업자들에게 이러한 Complex Target & Control Chart를 적용한다면, 통계적인 지식 없이도 공정의 불량을 예방 할 수 있으리라 확신한다. 이러한 관리도를 사용하여 공정능력을 향상한다면, 일본과 같은 높은 수준의 공정능력을 확보 할 수 있을 것이다. 단, 본 관리도는 현장 작업자를 위한 불량예방을 위한 품질관리 도구이며, 공정변동을 관리하기 위해서는 엔지니어 측면에서 관리도의 활용도 병행되어야 한다.

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비정규 공정하에 붓스트랩 EWMA관리도의 수행도 평가 (Evolution of Performance for Bootstrap EWMA Control Chart under Non-normal Process)

  • 이만웅;송서일
    • 산업경영시스템학회지
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    • 제25권2호
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    • pp.50-56
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    • 2002
  • In this study, we establish bootstrap control limits for EWMA chart by applying the bootstrap method, called resampling, which could not demand assumptions about pre-distribution when the process is skewed and/or the normality assumption is doubt. The results obtained in this study are summarized as follows : bootstrap EWMA control chart is developed for applying bootstrap method to EWMA chart, which is more sensitive to small shifts of process. With the purpose of eliminating a skewness of the resampling distribution, the bootstrap control limits are established by using a modified residual, and its performance is analyzed by ARL. It is shown that the bootstrap EWMA control chart developed in this study includes the properties of standard EWMA control chart that is sensitive to a small shift, and detects process in out of control more quickly than standard EWMA chart.

Pre-Control의 수행도에 관한 소고 (A Note on the Performance of Pre-Control)

  • 서순근
    • 품질경영학회지
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    • 제44권3호
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    • pp.587-600
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    • 2016
  • Purpose: This paper evaluates the performance of the pre-control(PC), an alternative to statistical process control techniques and compares with a control chart considering the tolerance of process. Methods: The previous studies for PC have drawbacks that PC with two linked stages, qualification and running, are discussed separately and independently. Hence this paper analyzes the performance of PC by integrating two stages. Results: Average outgoing quality limits to grasp the outcome of PC are provided by computational results for two process capability indexes, $C_p$ and $C_{pk}$ and the usefulness of PC from comparative experiments with modified control charts is commented. Conclusion: Helpful guidelines for quality managers to apply PC in practice and areas of process for PC to be more benefit are presented.

붓스트랩 방법을 이용한 로버스트 관리도 (Robust Control Chart using Bootstrap Method)

  • 송서일;조영찬;박현규
    • 산업경영시스템학회지
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    • 제26권3호
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    • pp.39-49
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    • 2003
  • Statistical process cintrol is intended to assist operators of a stable system in monitoring whether a change has occurred in the process, and it uses several control charts as main tools. In design and use of control chart, it is rational that probability of false alarm is minimized in stable process and probability of detecting shifts is maximized in out-of-control. In this study, we establish bootstrap control limits for robust M-estimator chart by applying the bootstrap method, called resampling, which could not demand assumptions about pre-distribution when the process is skewed and/or the normality assumption is doubt. The results obtained in this study are summarized as follows : bootstrap M-estimator control chart is developed for applying bootstrap method to M-estimator chart, which is more robust to keep ARL when process contain contaminate quality characteristic.

$\bar{x}$ 관리도의 표준관리한계와 부트스트랩 백분률 관리한계의 수행도 비교평가 (Comparison and Evaluation of Performance for Standard Control Limits and Bootstrap Percentile Control Limits in $\bar{x}$ Control Chart)

  • 송서일;이만웅
    • 산업경영시스템학회지
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    • 제22권52호
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    • pp.347-354
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    • 1999
  • Statistical Process Control(SPC) which uses control charts is widely used to inspect and improve manufacturing process as a effective method. A parametric method is the most common in statistical process control. Shewhart chart was made under the assumption that measurements are independent and normal distribution. In practice, this assumption is often excluded, for example, in case of (equation omitted) chart, when the subgroup sample is small or correlation, it happens that measured data have bias or rejection of the normality test. A bootstrap method can be used in such a situation, which is calculated by resampling procedure without pre-distribution assumption. In this study, applying bootstrap percentile method to (equation omitted) chart, it is compared and evaluated standard process control limit with bootstrap percentile control limit. Also, under the normal and non-normal distributions, where parameter is 0.5, using computer simulation, it is compared standard parametric with bootstrap method which is used to decide process control limits in process quality.

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Poisson GLR 관리도 (Poisson GLR Control Charts)

  • 이재헌;박종태
    • 응용통계연구
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    • 제27권5호
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    • pp.787-796
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    • 2014
  • Poisson 분포를 따르는 결점수를 관측하여 공정을 관리할 때 표본 크기를 동일하게 유지하기가 힘든 경우가 많다. 이 논문은 표본 크기가 동일하지 않은 경우 Poisson 공정모수의 변화를 탐지하는 GLR(generalized likelihood ratio) 관리도 절차를 제안하고 있다. 또한 제안된 GLR 관리도의 효율을 모의실험을 통하여 기존에 연구된 CUSUM 관리도들과 비교하였다. 모의실험 결과, 제안된 GLR 관리도는 공정모수의 다양한 변화에 대해 효율이 대체적으로 양호했으며, CUSUM 관리도에서 실제 공정모수의 변화값이 미리 지정한 값과 차이가 많이 날 경우 CUSUM 관리도에 비해 효율이 월등히 좋음을 알 수 있었다.

Effects of Spinal Mobilization with Leg Movement and Neural Mobilization on Pain, Mobility, and Psychosocial Functioning of Patients with Lumbar Disc Herniation: A Randomized Controlled Study

  • Seung Jin Kim;Ho Young Jang;Suk-Min Lee
    • Physical Therapy Rehabilitation Science
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    • 제12권2호
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    • pp.92-104
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    • 2023
  • Objective: The purpose of this study was to investigate the effect of spinal mobilization with leg movement (SMWLM) and neural mobilization (NM) in patients with lumbar disc herniation (LDH) accompanied by radiating pain. Design: Three-group pre-test-post-test control group design. Methods: We enrolled 48 participants, whom we randomly assigned to three groups. The SMWLM group (n=16) underwent 20 min of conventional physical therapy (CT) and 20 min of SMWLM. The NM group (n=16) underwent 20 min of CT and 20 min of NM. The control group (n=16) underwent 20 min of CT. These interventions in all the groups were performed three times a week for 4 weeks. Numeric pain rating score (NPRS), body grid chart score (BGCS), passive straight leg raise (PSLR), active lumbar flexion range of motion (ALFROM), korean version oswestry disability index (KODI), and korean version fear avoidance beliefs questionnaire (KFABQ) were measured pre- and post-intervention. Results: In all three groups, the NPRS, PSLR, KODI, and KFABQ scores were significantly different pre- and post-intervention (p<0.05). Significant differences were observed in BGCS and ALFROM in the SMWLM and NM groups pre- and post-intervention (p<0.05). The SMWLM group showed more improvement in the NPRS of leg pain, ALFROM, and KFABQ score than that exhibited by the NM and control groups (p<0.05). Conclusions: Both SMWLM and NM were effective for improving back and leg pain, centralization of symptoms, mechanical sensitivity, lumbar mobility, lumbar functional disability, and psychosocial functioning in patients with LDH with radiating pain.

The Effect of a Social Skills Program on Violent Behaviors in Children Aged 60~72 Months

  • Kuzlu Ayyildiz, Tulay;Cimete, Guler
    • 대한간호학회지
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    • 제49권6호
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    • pp.771-782
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    • 2019
  • Purpose: To determine the effects of a child and parent program on developing social skills for preventing violent behaviors in children aged 60~72 months through a specially developed pre and posttest, control group, quasi-experimental study. Methods: A social skills development program based on Gardner's Multiple Intelligence Theory was used. The data were collected using the Social Skills Assessment Scale (SSAS), a Chart to Monitor Verbal and Behavioral Violence in Children, the Parental Attitude Scale and the Parent Interview Form. This quasi-experimental study that included a pretest, posttest, and control group had a sample comprising 67 children and parents, with 36 in the experimental group, and 31 in the control group. Results: Over a six-month period, while the social skill scores of the children in the experimental and control groups increased, their violent behaviors decreased (p<.050). Increase in social skill scores and decrease in violent behaviors were higher in the experimental than in the control group children (p<.050). The parents in the experimental group stated that they had started to empathize with their children, using "I" language, and applied rules more consistently after the program. Conclusion: This program was successful in preventing violent behaviors in children through the development of social skills. Hence, it can be effectively implemented through a teacher/nurse collaboration.

경추의 전신조정술 관절치료가 관절가동범위에 미치는 영향 (The effect of motion according to general coordination manipulation treatment on cervical)

  • 김형수;김은영;구봉오;배성수
    • The Journal of Korean Physical Therapy
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    • 제15권4호
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    • pp.90-102
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    • 2003
  • Purpose: The purpose of this study is to search effect that GCM joint treatment gets to range of motion of cervical, lumbar, trunk and anke. And cervical gets in ankle joint. Methods: Estimated body deformity using GCM body type assesment chart then measured range of motion of each region. After control group did as act freely after do experiment pre measurement control group did post measurement. After control group did as act freely after do experiment premeasurement, control group did postmeasurement. Each region was measured by measurer who each subject person differs. Experimental group did GCM joint treatment and all measurements each region by measurer who each subject person differs three times measure postmeasurement after premeasurement. When measure with each measurement, measured after leave and walk time interval for 10 minutes. Result: For the analysis of the result of experiment, the results is change amount comparison increased to keep in mind except cervical flexion and both ankle joint's dorsiflexion after experiment of experimental group. In experimental group, cervical, lumber and ankle joint of range of motion was significantly increased(p<.05).

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다축-다변량회귀분석 기법을 이용한 회분식 공정의 이상감지 및 통계적 제어 방법 (Fault Detection & SPC of Batch Process using Multi-way Regression Method)

  • 우경섭;이창준;한경훈;고재욱;윤인섭
    • Korean Chemical Engineering Research
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    • 제45권1호
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    • pp.32-38
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    • 2007
  • 통계적인 공정 제어 기법을 회분식 공정에 적용하여, 일반적인 회분식 공정의 데이터를 통해 보다 빠르고, 손쉽게 공정의 상태를 진단할 수 있는 시스템을 구현해 보았다. 대표적인 회분식 공정의 하나인 반도체 식각공정과 반회분식 스타이렌-부타디엔 고무 생산 공정의 데이터를 이용하여 공정 변수와 공정의 상태간의 연관 관계를 규명할 수 있는 모델을 수립하였으며, 이 모델의 출력(output) 결과를 이용해 통계적 공정 제어 차트를 구성하고, 시간에 따른 공정의 추이를 분석해 이상을 판별해 보았다. 회분식 공정의 다축(multi-way) 데이터를 두개의 축으로 만드는 펼치기(unfolding) 과정을 거쳤으며, 모델링 방법으로는 Support Vector Regression 및 Partial Least Square 등의 다변량 회귀분석 방법을 이용하였다. 또한 에러차트 및 변수 기여도 차트(variable contribution chart)를 이용해 이상의 세기, 형태 및 이상 데이터에 대한 각 변수들의 기여도를 계산해 보았으며, 그 결과 이상의 발생 유무 및 발생시점 뿐만아니라 이상의 세기 및 원인 까지 진단해 볼 수 있는 우수한 성능을 보이는 것을 확인할 수 있었다.