• Journal of Power System Engineering
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• v.5 no.3
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• pp.73-79
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• 2001

The purpose of this investigation is experimentally to clarify the machinability and tool wear of STS 304 steel pipe material for piping. In order to determine the effects of cutting parameters and tool wear on thrust, torque, AE RMS, drilling is conducted on CNC milling machine. In this experiment, it is measured that thrust, torque, tool wear length, tool wear area and AE RMS during drilling using Hss tool. It has been found that a) During the drilling, the thrust and the torque of the STS 304 pipe are received more the effect of the feed than the spindle speed and the thrust increase with the increase of feed, b) The value of the AE RMS is been larger the effect of the cutting speed than the feed rate, and the value of the AE RMS increase with the increase of spindle speed, c) It has been found that the suitable feed in feed condition of 0.03, 0.05, 0.1, 0.15mm/rev is below 0.05mm/rev, d) The value of the AE RMS was shown a characteristic of the jump value during it was a sudden inrcrease of the tool wear. The increased character of the AE RMS value can be known an effective factor of the tool wear detection, and e) It can be quantitatively evaluated the condition of the tool according to calculate a area of the drill wear image which is obtained by a vision system.

• Tribology and Lubricants
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• v.32 no.1
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• pp.32-37
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• 2016

The wear characteristics of metal ball and seat in a metal-seated ball valve significantly affect the performances such as leakage and valve torque. In this work, the wear characteristics of metal ball and seat are experimentally investigated. A stainless steel ball and seat with a high corrosion-resistant coating are prepared and a component level test was performed. The hardness and surface roughness of specimens cut from the metal ball and seat are measured before and after the test using a micro-Vickers hardness tester and confocal microscopy, respectively. In order to assess the wear characteristics, the surfaces of the specimens are carefully examined after the test. The confocal microscope data show that the surface roughness values of both the ball and seat increase by a factor of 3-4, which may lead to an increase in valve torque. However, the wear of the seat is found to be more significant than that of the ball. In addition, a comparison of the surfaces of the ball and seat before and after testing revealed that adhesive and abrasive wear are the major wear mechanisms. The results of this study may aid in the design of metal-seated ball valves from the tribological point of view.

• Tribology and Lubricants
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• v.33 no.4
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• pp.168-186
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• 2017

This paper presents a wear analysis procedure for calculating the wear of journal bearings during the start-up and coast-down cycles of a motoring stripped-down single cylinder engine operating with a tilted shaft. In order to decide whether the lubrication state of a journal bearing is in the mixed-elasto-hydrodynamic lubrication regime, we utilize lift-off speed and MOFT (most oil film thickness) under mixed-elasto-hydrodynamic lubrication regime at the corresponding aligned shaft. We formulate an equation for the modified film thickness in a misaligned journal bearing considering the additional wear volume described in Part I of this study. For this, we use the calculation results of the degree of misalignment and tilting angle obtained after finding the eccentricities of the two bearings supporting the crankshaft of a single cylinder engine. In this Part II, we calculate the wear of journal bearings using the fractional film defect coefficient, the asperity load sharing factor, and the modified specific wear rate for the application of mixed-elasto-hydrodynamic lubrication regime. We show that the accumulated wear volume after turning the ignition switch on and off once, increases to ${\sigma}=39{\mu}m$ and then decreases from ${\sigma}=39{\mu}m$ with increasing in surface roughness.

• Journal of the Korean Society of Clothing and Textiles
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• v.34 no.7
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• pp.1138-1148
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• 2010

This study examines the characteristics of the online child-rearing community launched by the voluntary motivations of consumers, and the effects of those characteristics on community loyalty and the intentions to buy baby wear via community sites. The study was implemented by a descriptive survey method using an online questionnaire. The sample consisted of 212 members of online child-rearing communities. The data were analyzed by frequency, factor analysis, and regression analysis. Results are as follows. 1) It was found that there were four major factors of online child-rearing community characteristics, such as attachment/pleasure, practical/economy, interaction, and information. 2) All four factors had significant effects on community loyalty. 3) The factor attachment/pleasure had no significant effects on intentions to buy baby wear, but practical/economy, interaction and information had effects upon those intentions. 4) Loyalty to the online child-rearing community had significant effects on the intentions of community members to buy baby wear via the community site. In addition, online child-rearing community members are interested in information regarding baby wear as well as its purchase; this is why baby wear makers should perform cost efficient consumer group segmentation in a timely manner. In addition, it will be effective for their marketing activities to target such consumer groups as segmented.

• Journal of Fashion Business
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• v.4 no.2
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• pp.113-126
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• 2000

The purpose of the study was to investigate the level of latest fashion adoption of men's wear manufacturers and differences in the level of fashion adoption according to characteristics of brands and merchandise. Thus, this study was to be an exploratory study to examine the trends in fashion adoption of men's wear manufacturers. The questionnaire consisted of questions on 7 elements of fashion adoption and characteristics of men's wear manufacturers and their merchandise. The subjects were to evaluate their level of fashion adoption and rated on 5 point Likert-type scales of 7 elements. For the survey, the subjects were 100 employees (62 merchandisers, and 24 designers, etc.) who are employed by men’s wear manufacturers which have national brands, designer brands, license brands, import brands or private brands. The SAS PC+ package was used to calculate factor analysis, mean, t-test, ANOVA, Duncan's test, and Tukey's test. The results from the study were as follows: 1) The elements of fashion adoption of men's wear manufacturers were divided into 4 factors (clolr/fabric, silhouette/fashion image, detail/item coordination, accessories) which explained 83.61% of the whole of factors. 2) The highest score of mean of fashion adoption factors was fabric/color, but the lowest was accessory factor. 3) There were significant positive correlations between fashion adoption factors except between fabric/color and accessories. 4) There were significant differences in the level of fashion adoption according to types of brands and ages of target consumers. 5) There were significant differences in the level of fashion adoption according to the categories of apparel (suits vs. casual clothing) and types of suits and casual wear.

• Tribology and Lubricants
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• v.38 no.6
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• pp.274-280
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• 2022

There is a problem that semiconductor probe pin has a short lifespan. In order to solve this problem, Ti having excellent conductivity was doped to tetrahedral amorphous carbon (ta-C) having excellent hardness and abrasion resistance. This experiment was planned through the Taguchi robust design to determine the effect of the control factor of the ta-C:Ti coating film. The effect and contribution of control factors such as Unbalanced Magnetron Sputter(UBM) discharge current, arc discharge current, temperature, and bias voltage on ta-C:Ti characteristics were analyzed from the perspective of electrical and mechanical characteristics. The UBM discharge current was set to 4, 6, and 8 A. The main control factor of thickness and resistance is the UBM discharge current, and the thickness increased and the resistance decreased as the current increased. The decrease in resistance is due to the increase in the Ti content of the ta-C:Ti coating film. The arc discharge current was set to 60, 80, and 100 A. The main control factor of hardness and wear is the arc discharge current, and as the current rises, the hardness increases and the wear area decreases. This is due to the increased ta-C content of the ta-C:Ti coating film. Since resistance and wear are important for Probe Pin, the optimal level is set from the perspective of resistance and wear and a confirmation experiment is conducted.

• International Journal of Costume and Fashion
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• v.4
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• pp.21-45
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• 2004

The rapid development of science technology during the 20th century has greatly lowered the hours for labour, thus giving members of society extra time for leisure. With the increasement of leisure activities, sports casual wear has become one of the foremost leading items in the fashion industry, and among such sports casual, down wear has become the F/W season's most popular item. Because it generates high profits, many recognize it as a very important factor in lady's wear. Since the 1990's, down wear was widely applied to various sections of lady's, men's, and children's wear, and it has ceased to be limited to sports casual only. The purpose of this study was to fully understand the characteristics of down, and to develop crossover garments design desired not only in the F/W season but also the S/S season. It has been taken into consideration that many restrictions in sewing technique and material selection in manufacturing down as a fashion product exist when choosing a means of manufacture. That was why this study focused on the history and characteristics of down while analysing the works of domestic and foreign designers to concretely applicate them in fashion products. This study has divided the resulting down wear products according to consumer preference： vest, jacket, coat, one-piece, and skirt to applicate design manufacture of lady's wear in general, while designing and making artistically expressed down wear. There were 48 works developed as a result of this study, of which 41 were ready-to-wear, and the remaining 7 works were creative art wear.

• The Research Journal of the Costume Culture
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• v.7 no.2
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• pp.304-314
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• 1999

The objective of this study was to investigate clothing of disability for using to base data for development of human design clothing of disability. Data were obtained from 138 disability in the occupation school at Illsan and the association of disability at Seoul. The results were as follows. 1) Factor of diability were 21.8% by natur, 78.2% by posteriori. 2) Unsatisfier on ready-made clothing were infantile paralysis 20.6%, spinal obst-ruction 16.7%, physically handicapped 15%. 3) Apparel wore ready-to wear 64%, repaired ready-to wear 27.8%, home-to wear 0.7%.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 1999.11a
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• pp.49-56
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• 1999

A material was formulated with Phenol novolac and HEXA only. The cure kinetics and thermal characteristics of phenol novolac with various HEXA contents were peformed by differential scanning calorimetry and thermal gravimetric analysis. All kinetic parameters of the curing reaction including the reaction order, activation energy, and rate constant were calculated and reported. The results indicate that the curing reaction goes through an autocatalytic kinetic mechanism. The friction and wear characteristics of this material were determined using friction material testing machine. The friction coefficient of phenol novolac with various HEXA contents was determined using the PV(pressure & velocity) factor. The most stable and highest friction coefficient with a various pressure and velocity condition was found at HEXA 10 wt.% material. The specific wear rate per unit sliding distance with a various HEXA contents was reported.

• Journal of the Korean Society of Safety
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• v.18 no.4
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• pp.16-22
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• 2003

Generally the rupture of steam generator tubes proceeds from significant plastic deformation before failure. In this study, the burst pressures of damaged steam generator tubes were calculated from the plastic instability analysis with the finite element method. Two wear types, flat and circumferential types were considered. An equation for the burst pressure was proposed by using the strength reduction factor and the Svensson equation. The analysis results were compared with the experiment data from published references and they showed a good agreement with the experiment data.