• 품질경영학회지
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• 제18권1호
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• pp.77-83
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• 1990

A model for the economic design of an pn control charts with an assignale cause is presented and the loss-cost function for control schemes using these charts is derived. By minimizing this function with respect to the three control variables, namely, the sample size, the sampling interval and acceptance number, the economically optimal control plan can be optained. The article shows what influence increasing or decreasing condition, according to changeability of the size of these factors, of expected cost can have on the economy when an attribute control chart is used.

• 응용통계연구
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• 제30권3호
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• pp.487-501
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• 2017

최근 산업의 생산공정에서는 머신비전시스템을 통하여 제품의 품질특성치에 대한 정보를 이미지 데이터로 제공하는 경우가 많다. 따라서 산업과 의학 현장에서 이미지 데이터의 모니터링을 위해 관리도 절차의 필요성이 많이 대두되고 있다. 이미지 데이터를 모니터링하는 관리도 절차는 전통적으로 사용하는 관리도 절차와 유사한 점도 있지만, 데이터의 구조를 비롯하여 각 이미지에서 ROI를 설정하여 관리도 절차를 적용하는 등 서로 다른 점도 많이 있다. 이 논문에서는 생산공정에서 제공되는 이미지 데이터에 대해 관리도를 사용하는 절차를 소개하고, 이미지 또는 ROI 크기의 확대와 축소가 제품의 이상원인을 탐지하는데 어떠한 영향이 주는지를 모의실험을 통하여 알아보았고 각 관리도의 성능 또한 비교하였다.

• 대한산업공학회지
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• 제31권1호
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• pp.87-98
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• 2005

This research investigates economic-statistical characteristics of variable sampling size and interval (VSSI)$\bar{X}$charts under two assignable causes. A Markov chain approach is employed in order to calculate average run length (ARL) and average time to signal (ATS). Six transient states are derived by carefully defining the state. A steady state cost rate function is constructed based on Lorenzen and Vance(1986) model. The cost rate function is optimized with respect to six design parameters for designing the VSSI $\bar{X}$ charts. Computational experiments show that the VSSI $\bar{X}$ chart is superior to the Shewhart $\bar{X}$ chart in the economic-statistical sense, even under two assignable causes. A comparative study shows that the cost rate may increase up to almost 30% by overlooking the second cause. Critical input parameters are also derived from a sensitivity study and a few guideline graphs are provided for determining the design parameters.

• 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.

• Ocean and Polar Research
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• 제25권2호
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• pp.133-145
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• 2003

Deep-sea surface sediments were collected using a multiple corer at 20 stations of Clarion-Clipperton fracture zone in the northeast equatorial Pacific to understand latitudinal and longitudinal variations of geotechnical properties. There was a distinct latitudinal variation of geotechnical properties in the study area. The northern sediments showed finer grain size, lower water content and porosity, higher bulk density and specific grain density, lower liquid limits and plastic limits than their southern counterparts. The northern sediments are classified into inorganic clays of low plasticity (fat clays) on plasticity charts and normal to active clay on activity chart, whereas, the southern sediments are classified into fine-grained, highly-plastic, inorganic and biogenic silt or organic clays on plasticity chart and normal to very active clay on activity chart. When shear strength are considered, the northern sediments were found to be in unconsolidated states, while the southern ones to be normal to over-consolidated states. These latitudinal variations in sediment characteristics are likely caused by differences in productivity of surface water that controls sediment compositions, sedimentation rates, and grain solubility.

• 한국의류학회지
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• 제21권5호
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• pp.835-844
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• 1997

The purpose of the study was to develop a size chart for elderly women over 60s. In order to investigate the differences in sine and figure, we measured 28 measurements of the 400 samples in Seoul in 1996. The selected measurements were what required to draft a tailored jacket patterns. At the beginning of the study, we surveyed about the difficulties and complaints on clothing of elderly in general with the samples of customers and suppliers for larger sizes. They preferred a jacket when they go out, and most frequently experienced difficulty was not to be able to find a decent clothing of suitable design and fitting size.'chat is why we concentrated the study on the measurements required for jackets. We analyzed the data as follows. 1. As Korean apparel industry use K.S. sizing system, we decided to use the same measurement to categorize the samples, bust and height. 2. We found out the frequency in the sixte chart and suggests the production sixte for over 60s. 3. We suggested some of the distinct figure related characteristics for better fitting.

• 한국지반환경공학회 논문집
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• 제11권12호
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• pp.37-45
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• 2010

초미립자시멘트는 입자 크기가 마이크로화되어 실트성 지반까지 주입가능하지만 점성이 높아 침투성이 저하되는 단점이 있다. 본 연구에서는 유동화제를 사용하여 점성을 낮춘 초미립자주입재의 그라우팅 효과를 평가하고자 암반에서 초미립자주입재와 보통시멘트주입재의 주입효과를 비교하였다. 시추조사, 현장수압시험, 공내재하시험, 공내전단시험, 단위주입량분석, p~q~t chart 유형 분석을 실시하였다. 시험 결과 초미립자주입재를 사용하는 경우가 보통시멘트 주입재를 사용하는 경우보다 투수성, 탄성계수 및 변형계수, 단위주입량 및 주입재 회수율 등 측면에서는 유리하지만 전단응력 측면에서는 차이가 거의 없는 것으로 나타났다.

• 품질경영학회지
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• 제30권4호
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• pp.86-93
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• 2002

There are many different factors used in calculating control limits of control chart for variable data. Specially these factors are divided into two groups such as "no given standard" and "given standard"(namely, for analysis and management), but many kind of factors give rise to confusion. Therefore, It is necessary to manifest relationships among factors for easy application regardless of subgroup size. Many SQC textbooks show us plainly these factors, but do not have enough for adequate explanation of relationships among factors. Besides, notation of these factors of SQC textbook isn't coincide with another one, so necessity to the coincidence for the notation of the factors is highlighted during my work recently. In this study, the close examination about relationships among various factors (A-A3, B3-B6, D1-D4, C4, d2, d3 etc) was carried out. Spread sheet results are presented for getting factors according to subgroup size, by grouping as the case of "no given standard" and "given standard". How are these factors to be applied in statistical package (ex, Minitab) have been analyzed using a series of sample data. analyzed using a series of sample data.

• 한국의상디자인학회지
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• 제24권3호
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• pp.145-158
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• 2022

To grasp the size system of children's clothing online shopping malls, basic size charts for clothing products from 14 shopping malls were collected, compared, and analyzed. Looking at the age range of the basic size chart for each company, the minimum age is 1 year old, the maximum age is 14-15 years old, and all companies included ages up to 7 years. In addition, as for the number of size designations, children's clothing companies used seven to eight designations, and there were six types of size designation methods. Next, looking at the height range for each size, even with the same size designation method, the height range differed depending on the company. Also, the KS size standard does not consider body weight, but many companies use weight as a reference body size. Compared with the child body size data of the 6th Korean Body Size Data, the height and weight range for each size provided by the company showed differences between companies. The results of this study can be used in the future as basic data when revising and supplementing the clothing sizes in children's clothing companies.

• 한국의류학회지
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• 제26권6호
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• pp.923-934
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• 2002

The aim of this study is to suggest a Sizing System which has following points:- 1. In order to satisfy children of diverse figure shapes, we developed sizing system for three different figure type. Figure types are categorized into slim, normal, fat type based on the Rohrer Index. 2. For each figure types, we developed size chart using height bust circumference and hip circumference as basic measurements. The size codes are presented as the height-bust circumference or height-hip circumference. The size interval of height is 5cm for all figure types, such as 120,125,130 ‥‥ we developed a size allocation program, which is helpful when a customer doesn't know exact measurement of some body dimension. If a customer input measurements as much as he/she hows, the program allocates the nearest. At the end of the study, the sizing interaction sites were developed to present the results of the study clear.