• Journal of the Korean Society for Precision Engineering
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• v.27 no.10
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• pp.45-51
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• 2010

Electrical discharge drilling (ED-drilling) is a widespread machining method used to bore small holes with a high aspect ratio. This paper presents additional methods by which ED-drilling can improve machining speed, tool wear, and machined surface quality. Firstly, for high machining speed, and low tool wear, a new-type electrode that was ground on one side or both sides of the cylindrical electrodes was suggested to expel debris. The debris which is generated during the machining process can cause sludge deposition and secondary discharge problems: major reasons to decrease machining speed. This new-type electrode also reduced tool wear that was due to the decrease of unstable discharge in a machining gap by helping to expel waste water and debris from the gap. Secondly, to improve the machined surface roughness, an electrolyzation process was included after drilling. This process made the machined surface smooth by means of an electrochemical reaction between an electrode and a workpiece. In this study, the machining speed, electrode wear, and surface roughness were improved by the newtype electrode and the electrolytic process.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.353-354
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• 2006

The automatic inspection system is developed for the formed end part of automotive fuel pipe. The developed system has functions of outer diameter and formed end length measurement by LVDT(linear variable differential transformer) together with burr cleaning of automotive fuel pipe. The measured data are managed and controlled in real time by embedded SPC(statistical process control) program. The system is composed of mechanical part, electronic part and developed software system. These three parts operate automatically by mutual communication with each other. The developed system showed good results in finding inferior goods and efficiency improvement of the fuel pipe production line. It also eliminated the unreliable manual inspection processes and improved the confidence of product quality.

• Journal of Fashion Business
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• v.6 no.5
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• pp.41-47
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• 2002

Until now, there is a tendency of most textile research focused on the certain specific area of textiles in profound. This paper based on the case study of inspection of manufacturing men's formal wear has been investigated in the relationship between defection of men's formal wear and mechanical properties of textile for fall and winter. As a results of implementing Pearson's Correlation, density, blend rate, bending property, the rate of silk blend, the formality of sewing are correlated with defection of men's formal wear. However, it is required the defection of classification standard in various types of the finished product in a further study. In addition to increase efficiency of production in the manufacture, it is necessary for scholars to investigate the direction of research according to the contingency approach based on the systems approach.

• Transactions of Materials Processing
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• v.8 no.3
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• pp.269-275
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• 1999

A variable blank holding force method is proposed to improve deep drawing characteristics of sheet materials. In this method, the blank holding force (BHF) is controlled throughout a drawing process so that the punch load does not exceed a critical value, which is slightly less than the conventional process with the conforming process with the variable BHF is more flexible than the conventional process with the constant BHF and it could be used for improving the product's quality and drawability. In this paper we suggest a method controlling the BHF as a function of punch travel during the forming process. The optimization BHF curves are determined theoretically and experimentally. It is concluded that for the case of optimum BHF control methods the drawn cup height and the drawing formability achieved by this method are increased than those for constant BHF method. Also, as comparing the wall thickness distribution of the cup drawn by the constant BHF and the optimum BHF control, the BHF control reduce the wall thickness variation of the drawn cup at the cup wall and make the cup thickness distribution more uniformly than the constant BHF.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2012.10a
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• pp.577-582
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• 2012

Recently, noise reduction of air-conditioner is one of the important design factors for high quality product. Especially, customer complaints arise due to noise problem of the outdoor unit. After the operation of air-conditioner start, noise level of outdoor unit is increased gradually and sometimes abnormal noise occurs until it reaches steady state condition. The aim of this paper is to investigate the relation between noise of outdoor unit and thermodynamic properties of cycle at transient condition of room air-conditioner. In order to find out the noise characteristics of outdoor unit, noise and vibration measurements are carried out. Also, the thermodynamic properties of compressor and heat exchanger are measured by using temperature and pressure sensors and experimental results are discussed. Finally, we find out the relation between noise and cycle properties at starting of room air-conditioner and the improvement method to reduce noise level is proposed.

• Journal of the Korean Society of Food Culture
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• v.26 no.3
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• pp.283-294
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• 2011

The purpose of this study was to determine the optimal mixing conditions for three different amounts of mulberry juice, sugar, and agar powder for Yanggaeng prepared with mulberry juice. The experiment was designed according to the central composite design for estimating the response surface, which demonstrated 16 experimental points including 2 replicates for mulberry juice, sugar and agar powder each?? The mechanical and sensory properties of test materials were measured, and these values were applied to the mathematical models. A canonical form and perturbation plot showed the influence of each ingredient on the final product mixture. Measurement results of the mechanical properties showed a significant increase or decrease?? in pH, sugar content, water content, viscosity, l-value, a-value, b-value, hardness, springiness, chewiness, gumminess, cohesiveness. Also the sensory measurements showed a significant improvement?? in appearance, flavor, color, sweetness, texture, overall quality. As a result, the optimum formulation by numerical and graphical methods was calculated as mulberry juice 41.99 g, sugar 90.00 g, agar powder 3.18 g.

• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.283-292
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• 2013

This paper aims to propose a new steps of hypothesis testing using analysis process and improvement process in the six sigma DMAIC. The six sigma implementation models proposed in this paper consist of six steps. The first step is to establish a research hypothesis by specification directionality and FBP(Falsibility By Popper). The second step is to translate the research hypothesis such as RHAT(Research Hypothesis Absent Type) and RHPT(Research Hypothesis Present Type) into statistical hypothesis such as $H_0$(Null Hypothesis) and $H_1$(Alternative Hypothesis). The third step is to implement statistical hypothesis testing by PBC(Proof By Contradiction) and proper sample size. The fourth step is to interpret the result of statistical hypothesis test. The fifth step is to establish the best conditions of product and process conditions by experimental optimization and interval estimation. The sixth step is to draw a conclusion by considering practical significance and statistical significance. Important for both quality practitioners and academicians, case analysis on six sigma projects with implementation guidelines are provided.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2007.11a
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• pp.5-9
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• 2007

The construction method for Foamed-Concrete has not been important due to following process of construction work. However, according to the code about enhance of energy saving design policy and impact noise, noised isolation has been used in construction site so that the resistance for cracking and capability for insulating of Foamed-Concrete has been required. Therefore, new alternatives are demanded. Optimum mixing design, which can get the improvement of insulation and resistance of crack for Foamed-Concrete adding EVA chip, was derived and also the device, applying to construction site, was invented to equalize quality. This device can measure quantity of all input and placement, and show up the sum of placement and mixing design on a touch screen. This valuable construction method is friendly environment and recycling method because of using EVA chip, by-product of an EVA insole scrap burned or embedded, as a light-weight aggregate.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.68-78
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• 2014

Recently, companies are trying to gain a competitive advantage in the market to meet the voice of customer. For this purpose, QFD has been used as product development technology in many areas to include the customer' requirements. Also, Kano model has been used to understand the customer' requirements for an effective way. Therefore integration of Kano model and QFD can more efficiently reflect the customer' requirements when designing a new service. This paper proposes PI index by taking into account the current satisfaction position of our company and competitors while IR (Improvement Ratio) value was set uniformity. This study suggests a more accurate index to predict potential improvements and calculates the final importance or priority. Through case studies targeted at elevator maintenance companies, we can have a general idea how much to improve in the near future and estimate the final importance of customer requirements.

• Human Ecology Research
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• v.53 no.6
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• pp.619-628
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• 2015

Baby boomers who have rebuilt the Korean economy over the last half a century are now transitioning into a silver generation who are over 65 years of age. New silver consumers are qualitatively and quantitatively different from the previous generation and are considered to be 'the single most consumption-leading generation.' The number of new silver consumers using department stores and traditional markets has increased. SPSS ver. 21.0 was used with the methods of frequency analysis, t-test, one-way analysis of variance (ANOVA), device master record test, and regression analysis. This research studies consumer satisfaction of new silver consumers on department stores and traditional markets among retailing. The improvement of the parking environment is the most urgent issue for traditional markets because the long-term assessments of parking areas indicate that it is necessary to provide improved convenience for consumers. Salesman satisfaction has improved and consumer satisfaction ranks salesman satisfaction high for traditional markets; however, price satisfaction is low and the distribution system should be improved to supply products at a lower price. Salesman and price satisfaction should be improved at depart stores. Traditional markets should also promote consumer satisfaction through consistent management to make consumers trust information in regards to quality control and production and distribution; in addition, department stores should increase consumer satisfaction by maintaining store systems such as product diversification and display, cleanness, and atmosphere.