• 산업경영시스템학회지
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• 제29권2호
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• pp.97-103
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• 2006

Recently, the control chart is developed for monitoring processes with normal short production runs by the coefficient of variation(CV) characteristic for a normal distribution. This control chart does not work well in non-normal short production runs. And most of industrial processes are known to follow the non-normal distribution. Therefore, the control chart is required to be developed for monitoring the processes with non-normal short production runs by the CV characteristics for a non-normal distribution. In this paper, we suggest the control chart for monitoring the processes with a gamma short runs by the CV characteristics for a gamma distribution. This control chart is denoted by the gamma CV control chart. Futhermore evaluated the performance of the gamma CV control chart by average run length(ARL).

• 대한산업공학회지
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• 제13권2호
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• pp.97-103
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• 1987

Skip-Lot sampling plan is formulated in terms of renewal process. This approach facilitates studying the average outgoing quality in a short production run of length t, AOQ (t). By numerical studies it is found that the long-run average outgoing quality (AOQ) greatly overestimates AOQ (t) for short runs.

• 대한산업공학회지
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• 제15권1호
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• pp.89-103
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• 1989

In this paper the approximate average outgoing quality and properties of a class of continuous sampling plans in a short production run are investigated when the quality of successive units follows a two-state time-homogeneous Markov chain. The results of previous studies can be obtained as special cases. It is observed that the long-run average outgoing quality limit values under the statistical control differ significantly as compared to the case of short production runs in a Markov-dependent production process.

• Industrial Engineering and Management Systems
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• 제6권1호
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• pp.11-21
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• 2007

The PDCA (Plan, Do, Check and Act) cycle is often used in the field of quality management. Recently, business environments have become more competitive, and the due time of products has shortened. In a short production run process, to increase efficiency of management, the necessity for distinguishing the PDCA design that starts with PLAN and the CAPD design that starts with CHECK has been clarified. Starting from Duncan (1956), there have been a number of papers dealing with the economic design of control charts from the viewpoint of production run. Some authors (Gibra, 1971; Ladany and Bedi, 1976; etc.) have studied the economic design for finite-length runs; other authors (Crowder, 1992; Del Castillo and Montgomery, 1996; etc.) have studied the economic design for short runs. However, neither the PDCA nor the CAPD design of control charts has been considered. In this paper, both the PDCA and CAPD designs of the $\bar{\x}$ chart are defined based on Del Castillo and Montgomery's design (1996), and their mathematical formulations are shown. Then from an economic viewpoint, the optimal values of the sample size per each sampling, control limits width, and the sampling interval of the two designs are studied. Finally, by numerically analyzing the relations between the key parameters and the total expected cost per unit time, the comparisons between the two designs are considered in detail.

• 품질경영학회지
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• 제28권2호
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• pp.70-88
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• 2000

Short runs where it is neither possible nor practical to obtain sufficient subgroups to estimate accurately the control limit are common in modem business environments. In this study, the standardized control chart, Hillier's exact method, Q chart, EWMA(Exponentially Weighted Moving Average) chart for Q statistics and EWMA chart for mean and absolute deviation among many SPC(Statistical Process Control) techniques for short runs have been reviewed and advantages and disadvantages of these techniques are discussed. The simulation experiments to compare performances of these variable charts for process mean and variations are conducted for combination of subgroup size, scale and timing of shifts of process mean an/or standard deviation. Based upon simulation results, some guidelines for practitioners to choose short run SPC techniques are recommended.

• 산업경영시스템학회지
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• 제27권3호
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• pp.14-20
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• 2004

The coefficient of variation(CV) which is a relatively dimensionless measure of variability is widely used to describe the variation of sample data. However, the properties of CV distribution are little available and few research has been done on estimation and interpretation of CV. In this paper, we give an outline of statistical properties of coefficient of variation and design of control chart based on this statistic. Construction procedures of control chart are presented. The proposed control chart is an efficient method to monitor a process variation for short production run situation. Futhermore, we evaluated the performance of CV control chart by average run length(ARL).

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.1016-1020
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• 2001

The spinning is a very effective manufacturing technology for short production runs in a variety of sizes and shapes, because it can form the cross-section or tubular parts various shapes. However extensive experimental and analytical research has not been carried out. In this study, and fundamental experiment was conducted to improve productivity with process parameter such as tool path, angle of roller holder(a), feed rate(v) and corner radius of forming roller(Rr). These factors were selected as variables in the experiment because they were most likely expected to have and effect on spring back. The clearance was controlled in order to achieve the precision product which is comparable to deep drawing one. And also thickness and diameter distribution of a multistage cup obtained by shear spinning process were observed and compared with those of a commercial product produced by conventional deep drawing.

• 한국인쇄학회지
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• 제24권2호
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• pp.1-10
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• 2006

In the past few years, the printing industry has witness a trend that has become ever more defined: due to the advent of digital technology, the production of short print runs has continued to gain in importance. An important initiative for the support of digital work flow in the manufacturing of printed products is CIP4 consortium. CIP4 stands for "International Cooperation for Integration of Prepress, Press and Post-press, it is an association of around forty international companies, mostly manufacturers of prepress, press and post-press, as well as suppliers and users. In this paper, we studied on the acting application of CIP4 work flow.

• 한국의류산업학회지
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• 제19권2호
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• pp.109-120
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• 2017

In the textile industry located in Gyeonggi-do, 85% of small-sized firms have less than 10 employees; in addition, the most of them are characterized by a vendor relying specialization system that conducts foundry from the vendor that managed marketing, textile design development, and quality checks according to unit stream. The breakaway of these vendors accelerated over the last 7 years; however, industry survival is at stake because the specialization system and orders have collapsed. The following four main policies must be implemented to overcome industry hardship. Policies have been derived from survey and analysis (present condition and trends) from industrial statistics and related policies in advanced and developing countries. First, a policy to promote cooperation between small-sized foundry unit-streams. Second, unification of the marketing support function with a textile design and development support system. Third, the introduction of policy support-management system customized according to developmental stages (tall process${\rightarrow}$fabric production${\rightarrow}$sales${\rightarrow}$clothing production sales). Fourth, foundation of a control tower that puts these tasks in a vehicle and runs them and the division of roles with the central government. We must propel main tasks to manifest the developmental potential (develop eco-friend dyeing and processing technologies, change to the young next CEO in business environment, and grow the of knit market) of the Gyeonggi Textile Industry in a short period to present a condition where these four main policies are running.

• Nuclear Medicine and Molecular Imaging
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• 제40권4호
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• pp.228-232
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• 2006

목적 : $[^{18}F]F_2\;(T_{1/2}=110\;min)$ 기체를 이용하여 친전자성 치환반응으로 방사성동위원소 $^{18}F$을 표지하는 방법은 새로운 앙전자방출단층촬영용 방사성의약품 개발 분야에서 유용하게 이용되고 있다. 그림에도 불구하고 $[^{18}F]F_2$를 높은 생산수율과 비방사능으로 생산하기 위한 표적 개발 연구는 아직도 진행 중에 있다. 본 연구에서는 친핵성 치환반응으로 $^{18}F$을 도입하기 어려운 방사성의약품에 친전자성 치환반응으로 방사성동위원소를 도입할 수 있는 $[^{18}F]F_2$ 가스의 효율적인 생산에 관해 연구하였다. 대상 및 방법: 표적은 원추형 모양의 알루미늄 재질로 제작하였다. $[^{18}F]F_2$ 생산을 위한 핵반응으로 $^{18}O(p,n)^{18}F$를 사용하였으며, two-step 빔 조사방법을 이용하였다. 첫 번째 조사는 농축 $[^{18}O]O_2$가스를 표적에 충진한 후 빔 조사하여 $^{18}O(p,n)^{18}F$ 핵반응을 일으킴으로써 $^{18}F$를 생산한다. 생산된 $^{18}F$은 표적 챔버 기벽에 흡착된다. $[^{18}O]O_2$은 재사용을 위하여 냉각포획법으로 회수하였으며, $^{18}F$를 회수하기 위해 $[^{19}F]F_2/Ar$ 가스를 충진한 후, 두 번째 빔을 조사하여 방사성불소를 회수하는 방법으로 구성된다. 본 연구에서는 최적의 방사성불소 생산 조건을 찾기 위해 빔 조사 시간, 빔 전류 세기 농축 $[^{18}O]O_2$ 충진 압력 등의 변화에 따라 생산량을 평가하였다. 결과: 빔 조사 시간, 빔 전류, 농축 $[^{18}O]O_2$ 충진 압력 등의 조건을 변화시키면서 생산량을 평가한 결과 최적의 빔 조사 조건은 다음과 같다. 첫 번째 조사: 농축 $[^{18}O]O_2$을 약 15.0 bar충진, 13.2 MeV, 30 ${\mu}A$로 60-90분 조사; 두 번째 조사: 1% $[^{19}F]F_2/Ar$혼합가스 12.0 bar 충진, 13.2 MeV, 30 ${\mu}A$로 20-30분 조사 후 아르곤 가스로 회수하였을 때 EOB(end of bombardment) 기준으로 약 $34{\pm}6.0$ GBq(n>10)의 $[^{18}F]F_2$를 얻었다. 결론: $^{18}O(p,n)^{18}F$ 핵반응을 이용하여 친전자성 방사성동위원소 $[^{18}F]F_2$를 생산하였다. 표적 챔버는 알루미늄으로 제작하였으며 본 연구에서 연구된 $[^{18}F]F_2$가스는 친핵성 치환반응으로 방사성동위원소를 도입하기 어려운 다양한 방사성의 약품개발에 유용하게 이용될 수 있을 것이다.