• Journal of the Ergonomics Society of Korea
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• v.35 no.5
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• pp.343-359
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• 2016

Objective:In this study, we designed working clothes for livestock farmers to wear in spring and autumn to improve their work efficiency, conducted a physiological test on their performance, and evaluated their comfort. Background: In recent years, livestock farming in Korea has expanded, yet farmers' safety and sanitation levels remain low in hazardous environments that include organic dust, toxic gas, and heat stress, as well as the risk of accidents. Furthermore, most livestock farmers wear ordinary or dust-resistant clothes that are unsuitable for rearing livestock and compromise their safety and health. Thus, it is important to design specialized working clothes for livestock farmers that are comfortable and that minimize their health and safety risks. Method: To this end, we examined the literature on livestock (poultry, swine, and cattle) farmers' safety and sanitation issues, designed appropriate working clothes, and tested them in terms of sensory feel, physiological response, and subjective comfort. Results: The respondents expressed satisfaction with the new working clothes. The results of a physiological test showed a decline in temperature and humidity inside the clothes, a lower pulse rate, and a lower oxygen intake compared to the measurements taken when famers wore their previous working clothes. This indicates a fall in heat stress and fatigue, which was mostly consistent with the results of the assessment of subjective comfort. Conclusion: The results of the analysis show an improvement in the comfort of the new working clothes compared to the dust-resistant clothes that are widely worn. Based on this study, the new working clothes need to be further tested and evaluated to improve the design. Application: This study is expected to contribute to designing better working clothes for livestock farmers.

• Composites Research
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• v.28 no.3
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• pp.81-88
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• 2015

In this paper, we evaluate structural integrity of the wearable robot by using finite element analysis, which is made of CFRP(Carbon Fiber Reinforced Plastic) composite materials to be lightened. On the basis of the ASTM(American Standard Test Method), mechanical tests of the material are carried out in tensile, compressive and shear test for analytical evaluation. With the tested composite material, the main frame and two femoral frames of the robot is redesigned to satisfy the lightening design requirements. It is verified with the structural analysis that the redesigned frames are good for the part of the wearable robot.

• Korean Journal of Human Ecology
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• v.15 no.3
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• pp.397-404
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• 2006

The purpose of this study is to analyze the subjective sensations and preference for spring/fall casual cotton shirt fabrics, and to assist in developing shirt fabrics that offer maximum comfort in wearing sensation. The subjects of this study were male and female college students who assessed the tactile sensation of seven types of spring/fall shirt fabrics available on the market: plain weave and rib weave made of cotton and that of cotton mixed fabrics. The subjects were university students between the ages of 20 to 23, who were residing in the city of Cheongju, Korea. The questionnaires related to the fabrics hand were evaluated using a nine point bi-polar scale of 9 descriptive terms. Mean, t-test, F-test and $X^2$ were used for data analysis. The fabric hand evaluation on the seven types of shirts showed a significant difference in all of the 9 descriptive terms. There were partially significant differences in the subjective sensations according to fabric characteristics regarding shirt fabrics. As regards the difference in fabric hand according to gender, female students responded with more receptiveness and sensitivity than male students in the category of woven fabric evaluation. In particular, female students responded with more sensitivity to the sensation of dense and wrinkle sensations. There were significant differences in the purchase preference according to gender regarding casual shirt fabrics. Plain weave fabrics made of cotton was most preferred among male students, whereas rib weave fabrics made of cotton/polyester was most preferred among female students.

• Journal of The Korean Association For Science Education
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• v.16 no.1
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• pp.1-12
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• 1996

The purpose of this study is to investigate the psychological hierarchy structure of science concepts and to determine the effective teaching order by comparing the teaching effects of the psychological hierarchy order with those of teaching order of the current text in order to inquire validating evaluation framework of science curriculum sequence. Key concepts were selected by tasks analysis in the seven units of elementary and secondary school curriculum. Concept formation tests were developed to evaluate each concepts achievement,. The test items were made according to each of the concepts based on 12 prototype tasks developed by Frayer(1969). To identify the students' psychological hierarchy the test items were administrated to elementary and secondary school students. Ordering theory was used to identify the students' psychological hierarchy. Nonequivalent control group pretest-posttest design was used in this study as an experimental design. Teaching with psychological hierarchy order was applied tp experimental group and teaching with concept order described in the current text was applied to control group. The major results of this study are as followings: 1. The students' psychological hierarchy structures are different from logical hierarchy structures. 2. The science teachers' psychological hierarchy structures are different from not only logical hierarchy structures but also students' psychological hierarchy structures. 3. The mean score of experimental group applied psychological hierarchy order is significantly higher(p<.05) than the control group in the concept achievement.

• Journal of the Society of Naval Architects of Korea
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• v.52 no.1
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• pp.8-18
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• 2015

Reduction of the fuel oil consumption and corresponding greenhouse gas exhausted from ships is an important issue for today's ship design and shipping. Several concepts and devices on the superstructure of a container ship were suggested and tested in the wind tunnel to estimate the air drag reduction. As a preliminary performance evaluation, air drag contributions of each part of the superstructure and containers were estimated based on RANS simulation respectively. Air drag reduction efficiency of shape modification and add-on devices on the superstructure and containers was also estimated. Gap-protectors between containers and a visor in front of upper deck were found to be most effective for drag reduction. Wind tunnel tests had been carried out to confirm the drag reduction performance between the baseline(without any modification) configuration and two modified superstructure configurations which were designed and chosen based on the computation results. The test results with the modified configurations show considerable aerodynamic drag reduction, especially the gap-protectors between containers show the largest reduction for the wide range of heading angles. RANS computations for three configurations were performed and compared with the wind tunnel tests. Computation result shows the similar drag reduction trend with experiment for small heading angles. However, the computation result becomes less accurate as heading angle is increasing where the massively separated flow is spread over the leeward side.

• Proceedings of the Korean Geotechical Society Conference
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• 2009.09a
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• pp.545-553
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• 2009

A lot of long-span marine bridge, which connects land to island or island to island, are being designed and constructed lately in south-west coast in South Korea. In the past, caisson foundations in marine were mainly adopted in construction and stability aspect, however, nowadays with development of pile construction technology, drilled shaft foundations are mainly adopted. As the long span cable stayed bridge and suspension bridge applied with lots of loads are being designed, the scale of pile foundations are getting larger. As the construction cost of substructure including foundation in marine bridges is too high, the appropriate evaluation of the axial bearing capacity of pile becomes a core factor to decide the construction cost of foundation if the drilled shaft is adopted as foundation type of bridge. The evaluation values of skin friction and end bearing capacity of drilled shaft in weathered rock suggested in south Korea are only to introduce the foreign specifications, and most of them are designed in a kind of hard soil layer. Also the allowable load of pile section is less than the expected bearing capacity of pile in the soil condition since the allowable capacity of pile is undervalued. Recently in order to improve this factor the bi-axial hydraulic load test of pile was taken, the data of load transfer analysis of pile, unit of skin friction and end bearing capacity are accumulated. In our country, the design of piles are made with ASD, however, LRFD considering service, strength and extreme state was adopted in Incheon Grand Bridge implemented with BTL, and the research to systematize the resistance coefficient appropriate at home country are being progressed.

• The Journal of the Korea institute of electronic communication sciences
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• v.16 no.5
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• pp.835-844
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• 2021

In this paper, a power facility communication control device was designed to autonomously determine and separate the fault section through communication between power facilities in the smart grid distribution system. In the power facility communication control device, the control module was designed as a DSP to measure three-phase voltage and current, and the communication module was designed as an embedded-based Raspberry Pi to determine the fault section and realize the fault section separation through communication between power facilities. Communication between DSP and Raspberry Pi was designed by SPI communication, and communication between Raspberry Pi was designed based on Wi-Fi. Finally, a performance evaluation system based on three power facility communication control devices was built, and simulation verification was conducted for various fault events that may occur on the distribution line. As a result of the test evaluation, it was possible to confirm the effectiveness of the design methodology of the communication control device by showing the required response of the communication control device to all test cases.

• The Research Journal of the Costume Culture
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• v.29 no.6
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• pp.795-809
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• 2021

The purpose of this study was first, to clarify the clothing benefits that Uzbek female college students seek through clothing products; and second, to determine whether there is a difference in clothing involvement and clothing purchasing behavior according to the type of clothing benefits. Data were collected from 290 female university students from Tashkent, Uzbekistan, and analyzed using factor analysis, K-means group classification analysis, ANOVA, Duncan test, χ²-test, and frequency analysis. Respondents were classified into four types according to their clothing benefits: individuality/economy-pursuit, comfort-pursuit, fashion/brand-pursuit, and indifference. Significant differences were identified in terms of clothing involvement, information sources, clothing evaluation criteria, clothing store attributes, clothing wearing conditions (including monthly clothing expenses), number of purchases per year, clothing purchase location, clothing preference style, and clothing dissatisfaction. The fashion/brand-pursuit and personality/economy-pursuit types were influenced more by fashion and symbolism of clothing involvement, information sources, clothing evaluation criteria, and clothing store attributes. The individuality/economy-pursuit type purchased more frequently, spent more monthly clothing expenses, and used the internet. Clothing store attributes were considered more important by female students than the other attributes. In these results, clothing benefits were identified as consumer characteristics of female Uzbek college students and market segmentation was determined. In addition, it is meaningful in providing basic data for efficient marketing activities and minimizing trials and errors in establishing local-friendly strategies for target customers in different cultures.

• Journal of the Korean GEO-environmental Society
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• v.22 no.12
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• pp.71-77
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• 2021

As the number of using road in Korea increases, maintenance costs and traffic congestion costs also increase. In order to reduce maintenance cost and time of road, existing long - lived modular road system has been proposed. In this study, the design and performance evaluation of the adaptable support module, which is the substructure of the proposed system, was performed. Two adaptable (Cross-Beam type)support modules were designed and fabricated to determine the load and shape. A adaptable support module was constructed and a static load test was carried out to select the type with better performance. As a result of the load test, the maximum value of the measured earth pressure difference is about 158 kPa and the settlement amount is about 0.032 mm in the two types of adaptable support modules. Based on these results, it is concluded that the performance of the adaptable support module of the bottom curved cross-beam type is better.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.25 no.10
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• pp.1514-1519
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• 2001

This paper is concerned with design, manufacturing and performance test of LIPCA ( Lightweight Piezo- composite Curved Actuator) using a top carbon fiber composite layer with near -zero CTE(coefficient of thermal expansion), a middle PZT ceramic wafer and a bottom glass/epoxy layer with high CTE. The main point of this design is to replace the heavy metal layers of THUNDER by thigh tweight fiber reinforced plastic layers without losing capabilities to generate high force and large displacement. It is possible to save weight up to about 30% if we replace the metallic backing material by the light fiber composite layer. We can also have design flexibility by selecting the fiber direction and the size of prepreg layers. In addition to the lightweight advantage and design flexibility, the proposed device can be manufactured without adhesive layers when we use epoxy resin prepreg system. Glass/epoxy prepregs, a ceramic wafer with electrode surfaces, and a graphite/epoxy prepreg were simply stacked and cured at an elevated temperature (177 $^{circ}C$ after following an autoclave bagging process. It was found that the manufactured composite laminate device had a sufficient curvature after detached from a flat mold. The analysis method of the cure curvature of LIPCA using the classical lamination theory is presented. The predicted curvatures are fairly in agreement with the experimental ones. In order to investigate the merits of LIPCA, a performance test of both LIPCA and THUNDE$^{TM}$ were conducted under the same boundary conditions. From the experimental actuation tests, it was observed that the developed actuator could generate larger actuation displacement than THUNDERT$^{TM}$.