• Geomechanics and Engineering
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• v.34 no.6
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• pp.637-648
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• 2023

When an earth pressure balance (EPB) shield machine bores a tunnel in gravelly sand stratum, the excavated natural soil is normally transformed using foam and water to reduce cutter wear and the risk of direct muck squeezing out of the screw conveyor (i.e., muck spewing). Understanding the undrained shear behavior of conditioned soils under pressure is a potential perspective for optimizing the earth pressure balance shield tunnelling strategies. Owing to the unconventional properties of conditioned soil, a pressurized vane shear apparatus was utilized to investigate the undrained shear behavior of foam-conditioned gravelly sands under normal pressure. The results showed that the shear stress-displacement curves exhibited strain-softening behavior only when the initial void ratio (e₀) of the foam-conditioned sand was less than the maximum void ratio (e_max) of the unconditioned sand. The peak and residual strength increased with an increase in normal pressure and a decrease in foam injection ratio. A unique relation between the void ratio and the shear strength in the residual stage was observed in the e-ln(τ) space. When e₀ was greater than e_max, the fluid-like specimens had quite low strengths. Besides, the stick-slip behavior, characterized by the variation coefficient of measured shear stress in the residual stage, was more evident under lower pressure but it appeared to be independent of the foam injection. A comparison between the results of pressurized vane shear tests and those of slump tests indicated that the slump test has its limitations to characterize the chamber muck fluidity and build the optimal conditioning parameters.

• Composites Research
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• v.31 no.5
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• pp.260-266
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• 2018

This study investigates thermal and mechanical characterization of Hafnium carbide coating on the $C_f-C$ composites. The hafnium carbide coatings by vacuum plasma spray on the C/C-SiC composites are prepared to evaluate oxidation and wear resistance. We perform the thermal durability tests by thermal cycling at $1200^{\circ}C$ for 10cycles in air and investigates the weight change of each cycle. We also evaluate the wear and indentation behavior using tungsten carbide ball indenter as a mechanical evaluation. As a result, the HfC coating is beneficial to reduce of weight loss during thermal cycling test and improve the elastic property of C/C-SiC composite. Especially, the HfC coating improves the wear resistance of C/C-SiC composite.

• Journal of Korean Home Economics Education Association
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• v.21 no.1
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• pp.141-155
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• 2009

Purchasing used school uniforms is to reduce environmental pollution and expenses, and to enhance a feeling of wearing satisfaction for school uniforms by improving size fitting. In order to improve reutilization of used school uniforms, uniform purchasing behavior, awareness of the reutilizing markets of used school uniforms, and the running conditions of reutilizing markets of used school uniforms were analyzed through the survey. The subjects are 741 students of middle and high schools in Seoul and Kyeonggi Province in this study. The results are as follows. First, the better-fitted uniforms students wear, the higher satisfaction they feel. Therefore, it is desirable for students to wear the uniforms which are well fitted for each student. Second, the higher aware of environment students are and the more environmental preservation behavior they do, the higher awareness of wearing used school uniforms they are. In order to enhance students' awareness of reutilizing markets of used school uniforms, it is important to educate students about the environment systematically and to promote recycling events. Third, the reasons for not purchasing used school uniforms are difficulty in access to the repurchasing market and the sanitary problem. Therefore, it is suggested that environmental education which boosts students' awareness of environment and reutilization events should be held to make reutilizing markets of used school uniforms vigorous. Moreover, it is necessary to make reutilizing markets easy to access and improve cleaning and repairing system.

• Journal of Korea Multimedia Society
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• v.16 no.8
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• pp.962-971
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• 2013

In this paper, we propose a method to infer the user's behavior and situation through collected data from multi-sensor equipped with a smart clothing and it was implemented as a smart-phone App. This smart-clothes is able to monitor wearer users' health condition and activity levels through the gyro, temp and acceleration sensor. Sensed vital signs are transmitted to a bluetooth-enabled smart-phone in the smart-clothes. Thus, users are able to have real time information about their user condition, including activities level on the smart-application. User context reasoning and behavior determine is very difficult using multi-sensor depending on the measured value of the sensor varies from environmental noise. So, the reasoning and the digital filter algorithms to determine user behavior reducing noise and are required. In this paper, we used Multi-black Filter and SVM processing behavior for 3-axis value as a representative value of one.

• The Research Journal of the Costume Culture
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• v.8 no.3
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• pp.460-476
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• 2000

The purpose of this study was, accordingly, to examine male college student's general body consciousness and their actual condition of wearing clothing, as it's assumed that clothing, which everyone must always wear, might be effective in making up for the physical defect. The findings of this study were as follows : 1. Male College Students'Body Consciousness : They expressed some dissatisfaction with their own body, and they were most discontented with their height, among their bodies. They thought of the western-style shape as an ideal one, as what's considered by them to be ideal was thinner a little than them, being taller with wider shoulder, longer legs, smaller and white face. 2. Male College Students'Characteristics of Clothing Purchasing Behavior : In purchasing clothing, male college students were slightly sensitive about the physical part with which they wasn't satisfied. The clothing pattern preferred by them was an abstract one, and their favorite color was white or black. The greatest number of them put most emphasis on design in buying clothing, and they purchased clothing mainly at special fashion shop. On the whole, they showed an affirmative response toward wearing Korean costume, and they also had a positive opinion about the purchase of reformed Korean dress for everyday life. 3. Male College Students'Characteristics of Wearing Clothing : They appeared not to consider making up for physical weakness. Male college students favored aloha shirt and trousers when they went out. Male college students purchase clothing in consideration of individual, manly, classical, tender, or comfortable factors. 4. Relationship of Body Consciousness to Wearing Behavior : The degree to which they considered covering up physical weakness in wearing clothing was examined, by dividing them into two groups : one was a group that thought their own shape normal, and the other was a group that didn't think of their own shape as normal. As a result, both groups appeared not to consider covering up physical weakness.

• Fashion & Textile Research Journal
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• v.15 no.5
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• pp.733-742
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• 2013

This research explores the relationship between body image and clothing behavior in order to enhance self-efficacy among multicultural children based on a survey of 167 children. The statistical analysis indicated that children value(in decreasing order)family-esteem, friend-esteem, self-esteem, and school-esteem. School-esteem is the lowest, with boys displaying slightly higher levels of esteem than girls. A boys' self-esteem appears enhanced by higher satisfaction with overall appearance and weight; however, girls' self-esteem helped them address appearance and physical characteristics with positive attitudes. In addition, the clothing behavior of children significantly influenced self-esteem to differing degrees based upon gender. A boys' self-esteem can be increased by having them show interest in clothes rather than letting them wear similar clothes to their friends because their self-esteem can be heightened by higher interests and lower similarity. A girls' self-esteem can be augmented by the clean management of clothes and comfortable wearing due to their emphasis on manageability and comfort. This survey was limited to the Gyeonggi and Inchon area and leaves room for future studies.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.4
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• pp.99-106
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• 2006

High velocity oxygen-fuel thermal spray coating of the WC-Co cermet material is a well-established process for modifying the surface properties of the structural components exposed to the corrosive and wear attacks, and also these coating are well-known method to improve the fatigue strength of material. In this study, HVOF coated SM490B are prepared to evaluation of the effect of coating on tension and fatigue crack growth behavior. The pre-crack of the fatigue crack growth test specimens machined at deposited material area, heat affected zone and boundary, respectively. Through these test, the following results are obtained: 1) Tensile strength was about 498 MPa, and fracture occurred on base metal area. 2) The fatigue crack of coated specimens propagated more rapidly than non-coated specimen in all specimens. 3) In the same coating thickness specimens, the specimens with pre-crack at boundary more rapidly propagated than the specimens with pre-crack at HAZ and deposited material area. These results can be used as basic data in a structural integrity evaluation of rolled SM490B weldments considering HVOF coating.

• Journal of Korean Academy of Nursing
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• v.34 no.8
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• pp.1477-1482
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• 2004

Purpose. With the continuous spread of the AIDS virus and other sexually transmitted diseases (STDs) throughout Asia, it has become imperative for HIV/AIDS prevention outreach programs to stress the need for using prophylactics as one form of protection. This is particularly true for commercial sex workers. This pilot study was conducted to investigate the rate of condom use among the commercial sex workers in Korea and reasons why they frequently do not wear condoms during sexual intercourse. Methods. Fifty female commercial sex workers who worked in the Yong San area were recruited while outreach was performed and forty eight responses were analyzed due to two incomplete questionnaires. The data were collected on June 28, 2004 as part of an outreach program for condom use promotion. Results. The subjects ranged in age from 21 to 45 years. Nearly half of the subjects ($47.9\%$) did not consistently use condoms. The major reason for not using protection was clients' reluctances for using condoms. When condoms were used, the subjects preferred lubricant-rich and less painful condom during intercourse. Conclusion. Due to the inconsistent use of condoms, it is clear that many commercial sex workers and clients are susceptible to sexually transmitted diseases. Therefore, it is important to not only educate commercial sex workers, but also to educate their pimps and clientele about the importance of condom use. In general, it is recommended that practical strategies and a policy for condom use promotion be developed.

• Journal of the Korean Society of Costume
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• v.50 no.8
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• pp.29-41
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• 2000

This study was intended to grasp the actual condition of adult women's wearing foundation garments for the Korean adult women in their 20s to 40s. For this purpose, questionnaire research was conducted for 639 adult women in their 20s to 40s living in Seoul and Kyonggi Province. As for the reason for the purchase of foundation garments, It was found that the highest proportion of the responding adult women would buy brassieres when they were needed because the old ones were threadbare, followed by the purchase of brassiere when they caught their eyes in shopping around. As for the reason for the purchase of girdles, the highest proportion of the responding adult women could buy girdles when they were needed because their old ones were wornout, and next when bargain sale began at the department store or the large shopping center. The highest proportion of the responding adult women thought the source of information on foundation garments as the window display, followed by magazine. The adult women in their 30s collected information on foundation garments through the window display when buying brassieres or girdles. As for the product evaluation criteria of foundation garments, the highest proportion of the responding adult women thought highly of the feeling of wear in brassieres and girdles, followed by dimensions in brassieres and bodily correctability in girdles. As for the place of buying brassieres or girdles, the responding adult women showed it to be the department store. followed by the discount store and the well-known agency.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.265-271
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• 2005

Randomness exists in engineering. Tolerance, assemble-error, environment temperature and wear make the parameters of a mechanical system uncertain. So the behavior or response of the mechanical system is uncertain. In this paper, the uncertain parameters are treated as random variables. So if the probability distribution of a random parameter is known, the simulation of mechanical multibody dynamics can be made by Monte-Carlo method. Thus multibody dynamics simulation results can be obtained in statistics. A new concept called functional reliability is put forward in this paper, which can be defined as the probability of the dynamic parameters(such as position, orientation, velocity, acceleration etc.) of the key parts of a mechanical multibody system belong to their tolerance values. A flexible mechanical arm with random parameters is studied in this paper. The length, width, thickness and density of the flexible arm are treated as random variables and Gaussian distribution is used with given mean and variance. Computer code is developed based on the dynamic model and Monte-Carlo method to simulate the dynamic behavior of the flexible arm. At the same time the end effector's locating reliability is calculated with circular tolerance area. The theory and method presented in this paper are applicable on the dynamics modeling of general multibody systems.