• Journal of Korean Institute of Industrial Engineers
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• v.28 no.4
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• pp.407-414
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• 2002

The inherent reliability of a product is primarily determined in the design stage, and therefore, design engineers should be able to design reliability into the product in an efficient manner. Especially, the product should be designed such that its reliability is robust to various noise factors encountered in production and field environments. The Taguchi method can be effectively used for this purpose. However, there exist only a few attempts to integrate the Taguchi method with reliability design, and in addition, the existing works do not sufficiently consider the robustness and/or the distinction between noise and acceleration factors. This paper develops a unified approach to robust reliability design assuming that accelerated life tests are conducted at each combination of design and noise conditions. First, an experimental structure for assigning not only acceleration but also noise factors is presented. Second, the reliability at the use condition is estimated using the assumed accelerated life test model. Third, reliabilities are transformed into 'efforts' using an effort function which reflects the degree of difficulty involved in improving the reliability. Finally, an optimal setting of design parameters is determined based on the mean and standard deviation of the effort values. The above approach is illustrated with an example of a paper feeder design.

• Journal of Sasang Constitutional Medicine
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• v.20 no.3
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• pp.118-132
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• 2008

1. Introduction This study aims to survey knowledge and attitude of Sasang constitution investigators on the Sasang constitution clinical study. 2. Methods We have made up list of 24 Sasang constitution investigators who have conducted Sasang constitution clinical study before. The study has been surveyed for 20 investigators who has been experiencing clinical study bye-mail or interview. 3. Results 1) The recognition degree on clinical study for sasang constitutional investigators was relatively lower than that for non-oriental investigators. 2) Most investigators have difficulty in designing a Protocol and they thought Protocol is most important in clinical study. 3) The investigators has stressed the need of diagnosis guideline on Sasang Constitution in performing clinical study. 4. Conclusions Special course of clinical study for sasang constitutional investigators should be prepared to activate Sasang constitution clinical study. This course may set up the guideline of sasang constitution clinical study and designing protocol. Also it is urgent to develop constitution diagnosis guideline for clinical study.

• The International Journal of Costume Culture
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• v.12 no.2
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• pp.121-128
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• 2009

The goal of this study is to investigate the current conditions of apparels for the handicapped, identify the problems and recommend what are appropriate and functional apparels for the handicapped. The research method was to statistically process a survey on 200 handicapped by frequency analysis and cross tabulations. The study results are as follows. First, the degree of discomfort in daily activities was shown during toilet use and eating. Among clothes categories owned by the handicapped, most discomfort was felt in the order of everyday clothes, workout clothes, underwear, athletic shoes and working clothes. Second, children's clothing was most commonly preferred clothing style by handicap for the dwarfism. Comfortable clothes was preferred and relaxed, decent, and unique styles were preferred in the order. Soft feeling texture and absorbency was considered important as preferred clothing material. Third, sizes and designs were improvements wanted by the handicapped in apparel in the order. In addition, they wanted to wear apparel sensitive to the fashion just like the non-handicapped without showing the handicapped parts. There is a necessity for the government or municipalitiesto establish and run protected workplaces or independent workplaces for those who have studied apparel. The field is thought to require continuous and numerous follow-up studies such as researches on different physiques, standardization of apparel, segmentation of sizes and methods of producing custom apparel by function and handicap.

• Phonetics and Speech Sciences
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• v.2 no.4
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• pp.51-58
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• 2010

English vowels play an important role in the daily communication between Korean students and international visitors. However, many Korean students still have difficulty producing them distinctively. Vowels vary according to shapes of oral and pharyngeal cavities, which are mainly determined by the degree of jaw opening and tongue position. Yang (2008a) proposed a simplified chart of English and Korean vowels for an educational purpose. He also suggested to use wooden chopsticks to secure distinguishable jaw openings. The purpose of this study is to tap whether wooden chopsticks can be applicable to a method for correcting English vowel pronunciation. Twelve male and female students participated in the recordings of eight /hVd/ words followed by additional recordings with wooden chopsticks between upper and lower teeth. The first and second formant trajectories of both natural and controlled vowel productions were obtained and compared at six equidistant measurement points using Praat. Results showed that the formant values of natural vowel productions were comparable to those of controlled productions. Vowels with similar formant trajectories of male students were separated with the aid of chopsticks. The width of each chopstick could be controlled similarly in the experiment. The author concludes that wooden chopsticks can be useful to correct vowel pronunciation. Further studies are desirable for native speakers to make perceptual evaluations of controlled vowel productions by nonnative speakers.

• Journal of the Korean Society of Visualization
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• v.22 no.1
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• pp.79-84
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• 2024

As microchips' degree of integration is getting higher, its cooling problem becomes important more than ever. One of the promising methods is using fractal microchannel heat sink by mimicking nature's Murray networks. However, most of the related works have been progressed only by numerical analysis. Perhaps such lack of direct experimental studies is due to the technical difficulty of the temperature and heat flux measurement in complex geometric channels. Here, we demonstrate the direct visualization of in situ temperature profile in a fractal microchannel heat sink. By using the temperature-sensitive fluorescent dye and a transparent Polydimethylsiloxane window, we can map temperature profiles in silicon-based fractal heat sinks with various fractal scale factors (a=1.5-3.5). Then, heat transfer rates and pressure drops under a fixed flow rate were estimated to optimize hydrodynamic and thermal characteristics. Through this experiment, we found out that the optimal factor is a=1.75, given that the differences in heat transfer among the devices are marginal when compared to the variances in pumping power. This work is expected to contribute to the development of high-performance, high-efficiency thermal management systems required in various industrial fields.

• Fashion & Textile Research Journal
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• v.11 no.4
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• pp.614-620
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• 2009

This study surveyed Koreans' as well as foreigners' satisfaction about the size and appropriateness of size label for souvenir T-shirts currently selling in domestic and overseas countries. Questionnaire survey was conducted to 205 Koreans who located in overseas and foreigners who located in Korea. The questionnaire was composed with T-shirts purchasing, difficulties in size selection, and satisfaction of fitness and prepared in Korean and english version. The survey revealed that the most dissatisfaction with the size of souvenir T-shirts concerned difficulty in finding appropriate sizes due to discrepancy between size systems different among countries and actual T-shirt size. Particularly, the participants showed relatively low degree of satisfaction with the area of shoulders and necks. When the size satisfaction was compared across countries, there were significant differences in shoulder width, shoulder length, and neck circumference. The satisfaction with shoulder width was also different depending on gender. Female participants' satisfaction was significantly lower than that of male participants.

• School Mathematics
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• v.17 no.4
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• pp.531-553
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• 2015

This study discussed a sketch map and planar figure, classical contents in math curriculum of Korea. Two problems were posed. One was the degree of difficulty and ambiguous intentions of some contents in 5th grade math textbook of 2009 revised curriculum. The other was the status of sketch maps and planar figures in more general view. We looked into elementary mathematics textbooks of former Korean national curriculums and other countries to discuss the problems. The reason why the present Korean textbook has such contents was considered, based on the result of searching former Korean and foreign textbooks. The suggestions in view of expression and building of 3D shapes were also talked.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.5
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• pp.374-382
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• 2013

Robust design method developed by Genichi Taguchi has been very popular since the 1980s and there have been many academic and applied research works on this topic. However, college students and engineers in companies have had difficulty in understanding the method. This paper presents a procedure to implement the robust design method by an easy-to-execute paper helicopter experiment. A crossed array was adopted, which consists of a resolution IV fractional factorial design with 6 control factors and a factorial design with 3 noise factors. Three performance measures were analyzed; signal-to-noise ratio, mean, and standard deviation of the falling time of the paper helicopter that is to be maximized. Control-noise interaction plots are also given to evaluate the degree of the sensitivity of each level of the control factors to the noise factors. The procedure presented in this paper can be helpful to those who want to have basic knowledge in the robust design method.

• Journal of The Korean Society of Agricultural Engineers
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• v.48 no.4
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• pp.15-22
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• 2006

This study was conducted by the slump test and the consistency test of the cement mixed soil which is soil mixed with cement to investigate and estimate the difficulty degree of work and the proper water content. So I would like to present the fundamental data that establish the work standard of the cement mixed soil. In conclusion, in this study the slump value of the cement mixed soil increases over-all according to the increase of the water content although it has a little difference of the increase range and it is smaller than one of the soil. It is estimated that the aggregating and throwing work of the cement mixed soil which is mixed with 6% and 9% cement would be fine when it has the $25%{\sim}27%$ water content and the wall plastering work is the $30%{\sim}32%$ and the floor plastering work is the $30%{\sim}35%$ and the flowing and pouring work is the $40%{\sim}42%$ water content as well as the mold compacting work is the 20%.

• Journal of Dental Anesthesia and Pain Medicine
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• v.17 no.4
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• pp.281-287
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• 2017

Background: Various techniques have been introduced to decrease complications during nasotracheal intubation. A common practice is to use nasal packing with a cotton stick and 0.01% epinephrine jelly. However, this procedure can be painful to patients and can damage the nasal mucosa. Xylometazoline spray can induce effective vasoconstriction of the nasal mucosa without direct nasal trauma. In this study, we aimed to compare the efficacy of these two methods. Methods: Patients were randomly allocated into two groups (n = 40 each): xylometazoline spray group or epinephrine packing group. After the induction of general anesthesia, patients allocated to the xylometazoline spray group were treated with xylometazoline spray to induce nasal cavity mucosa vasoconstriction, and the epinephrine packing group was treated with nasal packing with two cotton sticks and 0.01% epinephrine jelly. The number of attempts to insert the endotracheal tube into the nasopharynx, the degree of difficulty during insertion, and bleeding during bronchoscopy were recorded. An anesthesiologist, blinded to the intubation method, estimated the severity of epistaxis 5 min after intubation and postoperative complications. Results: No significant intergroup difference was observed in navigability (P = 0.465). The xylometazoline spray group showed significantly less epistaxis during intubation (P = 0.02). However, no differences were observed in epistaxis 5 min after intubation or postoperative epistaxis (P = 0.201). No inter-group differences were observed in complications related to nasal intubation and nasal pain. Conclusion: Xylometazoline spray is a good alternative to nasal packing for nasal preparation before nasotracheal intubation.