• Transactions of the Korean Society of Machine Tool Engineers
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• v.16 no.1
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• pp.92-97
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• 2007

This study was carried out to minimize the lifting force and to design the slim sized frame of a height adjustment mechanism. This unit is designed for the display devices in order to enhance the ergonomics for effective height adjustment as well as to achieve much slimmer frame for the pedestal. A tolerance analysis of 6 sigma was applied to achieve smooth lift at design stage not to change the tolerance specification of gap several times in a roller type of lifting mechanism at mass production stage. The specification of minimum gap and the target of production yield ratio were agreed with a quality team before tooling. A DFSS simulation on drawings had been done with reasonable tolerance and achievable standard deviation(${\sigma}$) several times until the target specification of gap and yield ratio was met. Once tolerance and deviation(${\sigma}$) were fixed tooling start was done successfully. A CAE method was applied to achieve a slim design. Design parameters were frozen when those parameters matched the reference strength data of standard model. Through those tolerance analysis and CAE simulation the number of tool modification was reduced and production yield ratio was raised up without arguing quality specification at production stage in the end.

• Journal of the military operations research society of Korea
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• v.29 no.2
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• pp.131-147
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• 2003

The complexity of modern weapon systems using the intelligence technology demands that rapid and effective transition from force requirements to deployment and fielding. Thus this paper deals with the integration of development procedure, evolutionary acquisition, integrated test and evaluation, improvement of the requirements decision process, use of commercial products of high quality and low cost, specification deviation, and the effective use of dual use technology. In general, decision­makers, and military field users shall first consider the moving technology rapidly into use. This study is aimed to improve the defence acquisition management directive for timely force integration of weapon system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.18 no.36
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• pp.275-285
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• 1995

In recent years there has been increasing interest in the issue of process centering in manufacturing process, The traditional process capability indices Cp, Cpk and Cpu are used to provide measure of process performance, but these indices do not represent the issue of process centering. A new measure of the process capability index Cpm is proposed that takes into account the proximity to the target value as well as the process variation when assessing process performance. However, Cpm only considers acceptance cost for deviation from target value within specification limits, do not includes economic consideration for rejected items. This paper proposes flexible process performance measures that considered quadratic loss function caused by quality deviation within specification limits, rejection cost associated with the disposition of rejected items, and inspection cost. In this model disposition of rejected items are considered under perfect corrective procedures and the absence of perfect corrective procedures.

• Structural Engineering and Mechanics
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• v.68 no.3
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• pp.289-297
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• 2018

The real behavior of the RC structures constructed based on the assumed specifications of the used materials is matched with the designed ones when the assumed and the applied specifications in construction are the same. Despite in the construction phase of the reinforced concrete (RC) structures always it is tried to implement the same specifications of materials as given in the executive drawings, but considering the unpredicted/uncontrolled parameters that affect the specification of materials, always there is a deviation between the constructed and the designed materials' specifications. The objective of this paper is to submit a guideline for the evaluation of the strength and damage to the existing RC structures encountered deviation in materials' strengths. To achieve this goal, the lateral strength (plastic behaviors) and damage to twenty-five RC moment-resisting frames (MRFs) are studied by applying the inelastic analysis. In this study, a couple of concrete and reinforcement strengths' deviations are investigated. The obtained results indicate that in general, there is a semi-linear relationship between the deviation in the strength of reinforcement and the changes in the lateral strength values of the MRFs. The relative effect of the deviation in the strength of reinforcements is more than the relative effect of the deviation in the concrete strength on the damage rate. The obtained results could be a guideline for the engineers in the survey of the existing buildings encountered deviation in materials' strengths during their construction phase.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.41 no.3
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• pp.145-153
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• 2018

Taguchi regarded the concept of quality as 'total loss to society due to fluctuations in quality characteristics from the time of supplied to the customer.' The loss function is a representative tool that can quantitatively convert the loss that occurs due to the deviation of the quality characteristic value from the target value. This has been utilized in various studies with the advantage that it can change the social loss caused by fluctuation of quality characteristics to economic cost. The loss function has also been used extensively in the study of producer specification limits. However, in previous studies, only the second order loss function of Taguchi is used. Therefore, various types of losses that can occur in the process can't be considered. In this study, we divide the types of losses that can occur in the process considering the first and second loss functions and the Spiring's reflected normal loss function, and perform total inspection before delivering the customer to determine the optimal producer specification limit that minimizes the total cost. Also, we will divide the quality policy for the products beyond the specification limits into two. In addition, we will show the illustration of expected loss cost change of each model according to the change of major condition such as customer specifications and maximum loss cost.

• Journal of Fashion Business
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• v.11 no.4
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• pp.152-172
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• 2007

This research suggest the correspondent sizes of women's and men's ready-made clothes to export to China on the basis of KS size specification. The results of this study, with the cooperation of Sejung and Searte Companies exporting clothes to Ningbo City, Zhejiang Province in China, are as follows: 1. Corresponding Dimensions of China Women's Clothes According to Morrison's relative deviation method, the body measurement characteristics of Chines and Korean women in their 30s and 40s were compared. As a result, Chinese women were bigger in height, arm length, abdomen girth, and upper arm girth but smaller in shoulder length and shoulder width. The cluster analysis for body type classification was as follows: Type 1, tall and well-developed, was 34.8%. Type 2 with weaker upper body, medium height, narrow shoulders and a slim waist was 45%. Type 3 with stronger upper body, shortest height and wide shoulders was 20.2%. 2. Corresponding Dimensions of China Men's Clothes Based on the drop standard of KS K 0050, the body types of Chinese men in their 20s were classified. A body types were 55.77%, Y body types were 32.16%, B body types were 11.55% and BB body types were 1.51%. According to the criteria of ready-made dimensions of normal body type suggested in Korea Standards, and in consideration of the basic distribution reality of body dimensions, representative 5 sizes were selected. 3. The corresponding size specification of China women's and men's clothes based on those of KS size specification were presented here, showing product sizes and physical items in detail.

• Journal of Korean Society for Quality Management
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• v.20 no.1
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• pp.80-90
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• 1992

In industries, the capability indices $C_p$ and $C_{pk}$ can be used to provide measures of process potential capability and performance, respectively. The new approach advocated by Taguchi in quality control overcomes some problems in other approaches preventive management activities. Taguchi introduces the emphasis on loss function to improve quality of products on the side of customer. The proceeding concept of capability indices is not rational for the measurement of quality if the process mean is not equal to target value. The Taguchi approach is said to be more reasonable than the others in quality evaluation because of his loss function. However, the capability indices $C_{pm}{^+}$ and $C_{pn}$ using Taguchi's loss function only consider, acceptance cost for deviation from target value within specification limits. In other words, they do not include rejection cost for nonconformings that are failed to fall on the specification limits.

• Journal of the Korea Institute of Military Science and Technology
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• v.18 no.1
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• pp.55-65
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• 2015

This paper describes the results of a temperature analysis of Korea and its neighbor regions for temperature specification of weapon systems to be deployed in Korea, and introduces the concept of a standard deviation frequency of occurrence which represents a frequency of yearly occurrence. On the basis of this analysis, reasonable operational temperatures for the Korea weapon systems are recommended, and the regional frequency of yearly occurrence of temperatures worse than recommended operational temperatures in each country regions are presented.

• Journal of the Korean Data and Information Science Society
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• v.13 no.2
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• pp.285-294
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• 2002

The control chart is widely used tool for monitoring of the process. This paper deals with an interpretation of the process capability index(PCI) and process performance index(PPI) when the control chart is used for monitoring of the process. The main difference between the PCI and PPI is how we did estimate the process deviation. The PCI uses the within process variation and the PPI uses the total process variation, which is conceptually defined as sum of between process variation and within process variation. Easy interpretations of the PCI and PPI for field engineers are described. And some new approaches to interpretation of the process capability and performance index may be useful in early stabilization of new process.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.8 no.5
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• pp.76-82
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• 1999

During operating given working a robot manipulator makes some problems such as the accumulation of the error or the deviation from the command trajectory. These problems are mainly due to the disturbance noise or unmodeled system parameters. To solve these problems most of robot manipulators equip the controller. But if exact controller gains are not seleced we can't decrease the working efficiency(such as compensation about error or deviation) of the robot manipulator. So in this paper we present the controller gain tuning law by which we can find the controller gain which satisfies the per-formance specification of the robot manipulator during working of the robot. The proposed algorithm is derived from the Laypunov direct method. And by the simulation on the 4-axis SCARA type robot(SAMSUNG SM5 Robot) we guarantee the performance of this algorithm.