• Journal of Korea Foundry Society
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• v.43 no.2
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• pp.55-63
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• 2023

Due to the importance of the surface on the final slab quality, it is essential to maintain a smooth segment roll surface that is in touch with the thin solid shell during solidification. In this paper, the surface of the used continuous casting guide roll was analyzed to realize the mechanism of its surface deterioration. Surface analysis has revealed severe corrosion at two distinct areas leading to deep roughness occurring on the guide roll. Firstly, the severe corrosion follows prior austenite grain boundary due to exposure with acidic environment. Also, in heat affected zone (HAZ) where two cladding beads overlap, more severe corrosion takes place. The overheat input results in local ferritization without full melting which increases retained δ-ferrite content almost 10 times higher than surrounding area. Corrosion was observed to happen at the δ-γ interface where Cr depletion takes place.

• Journal of Advanced Marine Engineering and Technology
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• v.38 no.4
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• pp.409-417
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• 2014

Since the oil price has been significantly jumped for recent some years, the diesel engine of the merchant ship has been mainly used the heavy oil of low quality. Thus, it has been often exposed to severely corrosive environment more and more because temperature of the exhaust gas in a combustion chamber is getting higher and higher with increasing of using the heavy oil of low quality. As a result, wear and corrosion of most parts surrounded with combustion chamber is more serious compared to the other parts of the engine. Therefore, an optimum weldment for these parts is very important to prolong their lifetime in a economical point of view. In this study, four types of filler metals such as Inconel 625, 718, 1.25Cr-0.5Mo and 0.5Mo were welded with SMAW and GTAW methods in the forged steel which would be generally used with piston crown material. And the corrosion properties of weld metal, heat affected zone and base metal were investigated using electrochemical methods such as measurement of corrosion potential, anodic polarization curves, cyclic voltammogram and impedance etc. in 35% H2SO4 solution. The weld metal and base metal exhibited the best and worst corrosion resistance in all cases of filler metals. In particular, the weld metal welded with filler metals of Inconel 718 revealed the best corrosion resistance among the filler metals, and Inconel 625 followed the Inconel 718. Hardness relatively indicated higher value in the weld metal compared to the base metal. Furthermore, Inconel 625 and 718 indicated higher values of hardness compared to 1.25cr-0.5Mo and 0,5Mo filler metals in the weld metal.

• The Research Journal of the Costume Culture
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• v.23 no.5
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• pp.835-845
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• 2015

This study aims to suggest the proper ease for slim-fit jackets according to the number of buttons from a one-button jacket to four-button jackets for men in their 30's. The researchers carried out both an appearance evaluation and movement functionality evaluation. The results are as follows: When conducting the appearance evaluations, meaningful differences were found. The one-button jacket showed high scores for the 7.5 cm ease. The two-button jacket and the three-button jacket showed high scores for the 10.5 cm ease. The four-button jacket showed a high score for the 13.5 cm ease. Next, the results of the movement functionality evaluation showed the same trend; as the ease was increased from 7.5 cm to 13.5 cm, the scores increased. This is because if the garments offer more ease, this gives room for actions. Additionally, it showed that if there were fewer jacket buttons, then the results showed a high score. The researchers believe that if the number of jacket buttons is lower, then the area of the V-zone increases, so that there is more room for movement. The study suggests a proper chest ease of 7.5 cm for the one-button jacket, 10.5 cm for the two-button jacket and three-button jacket, and 13.5 cm for the four-button jacket, respectively.

• Transactions of the Korean Society of Pressure Vessels and Piping
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• v.11 no.1
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• pp.20-24
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• 2015

Steam generator(S/G) tubes in pressurized water reactor (PWR's) are subject to several types of degradation. This degradation includes denting, pitting, intergranular attack(IGA), intergranular stress corrosion cracking(IGSCC), fatigue, fretting and wear. Degradation can be derived from either the primary side(inside) or the secondary side(outside) of the tube. Recent issue for tube degradation in domestic steam generator is the tube end cracking on seal weld region. The seal weld region at the tube end and tube itself is regarded as a pressure boundary between the primary side and the secondary side. One of the Westinghouse Model-F S/G has experienced tube end cracking and its number of plugging approximately becomes to the operating limit up to 5% due to tube end cracking which was reported as SAI/MAI(single/multiple axial indication) or SCI/MCI(Single/multiple circumferential indication) from the results of eddy current testing. Eddy current mock-up test was carried out to determine the origin of cracking whether it is from weld zone area or parent tube. This result was helpful to analyze crack location on ECT data. Correct action on this problem was the installation of tube-end sleeve. Last year, after removing 340 installed plugs from tubes, selected 269 tubes took tube-end sleeve installation. Tube-end sleeve brought pressure boundary from parent tube to installed sleeve tube. Tube-end sleeve has the benefit of reducing outage period and increasing more revenue than replacing S/G. This paper is provided to assist interest parties in effectively understanding this issue.

• Journal of the Korean Society for Precision Engineering
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• v.6 no.1
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• pp.45-51
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• 1989

In metal cutting various types of chips are produced in consequence of cutting conditions. According to the type of chips the cutting mechanism is to be changed. Most of the cutting theory is based on the continuous chip because of its convenient analysis, but the occurrence of the saw-toothed chip depends upon the workpiece and/or the cutting conditions, one of which is titanium alloy used widely. Nowadays titanium alloys are used widely with the rapid development of aerospace structural engineering application, whereas the theory of cutting mechanism has not been established yet, and the formatting process has not been understood satisfactorily, either. Unfortunately several misconceptions, conflicting statements and statements needing further clarifi- cation are also found. In this paper an attempt is made to clarify the formation process of saw-toothed chips which are to be produced during the orthogonal cutting process of titanium alloys. They were machined at low speed to avoid the rapid tool wear. We observed the SEM-photographs of chips taken at the quick-st- opping device. It is hoped that a rational model of the mechanics of cyclic chip formation can be developed. The results obtained are as follows. 1. When a saw- toothed chip is formed, the shear band begins at the primary shear zone and trans- fers to the free surface, so that a segment is produced and it is completed by upsetting between the formatting segment and the formatted segment. 2. As the rake angle or the clearance angle increases in the machining of the titanium alloy, the chip approaches to that of the continous type. 3. When the rake angle and the clearance angle are increased the shear energy and the unit friction energy decrease, which shows the same aspect as that of the continuous chip.

• Proceedings of the KWS Conference
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• 2009.11a
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• pp.95-95
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• 2009

Zinc coatings provide the most effective and economical way of protecting steel against corrosion. There are three types of galvanizing lines typically used in production line in galvanizing industries,Galvanize (GI) coating (Zn-0.1-0.3%Al), Galfan coating (Zn-5%Al), Galvalume(GL) coating (45%Zn-Al). In continuous Galvanizing lines, the immersed bath hardware (e.g. bearings, sink, stabilizer, and corrector rolls, and also support roll arms and snout tip) are subjected to corrosion and wear failure. Understanding the reaction of these materials with the molten Zn alloy is becomes scientific and commercial interest. To investigate the reaction with molten Zn alloys, static immersion test performed for 4, 8, 16, and 24 Hr. Two different baths used for the static immersion, which are molten Zn and molten Zn-55%Al. Microstructures characterization of each of the materials and intermetallic layer formed in the reaction zone was performed using optical microscope, SEM and EDS. The thickness of the reaction layer is examined using image analysis to determine the kinetics of the reaction. The phase dominated by two distinct phase which are eutectic carbide and matrix. The morphology of the intermetallic phase formed by molten Zn is discrete phase showing high dissolution of the material, and the intermetallic phase formed by Zn-55wt%Al is continuous. Aluminum reacts readily with the materials compare to Zinc, forming iron aluminide intermetallic layer ($Fe_2Al_5$) at the interface and leaving zinc behind.

• Science of Emotion and Sensibility
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• v.20 no.2
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• pp.117-126
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• 2017

In this study, moisture transport characteristics for the woven and knitted fabrics made of 8 kinds of fiber materials using MMT (moisture management tester) were measured and discussed with the Bireck bt MMT and water evaporating rate (WER) measuring methods, which are vertical moisture transport methods. In addition, the drying property by MMT of the eight kinds of specimens was compared and discussed with the results measured by the vertical drying measurement. MMT experimental result which is horizental moisture transport appeared to be similar to the result of the Bireck method, which is the vertical moisture transport experiment. Absortion time measured from drip method of the fabrics made of the bamboo, linen, and cotton/nylon composite fabrics was short and thus they showed best wicking property, which was attributed to the low contact angle on the fabric surface and high porosity of the fabrics due to the staple yarn structure composed of the hydrophilic staple fibers. In drying property of the fabric specimens by MMT, maximum absorption radius of the dry-zone knit and bamboo woven fabrics were the highest and they showed the best drying property, which was a little different result compared with vertical drying measurement method. Half time of the drying rate in the MMT method was highly correlated with the fabric thickness and saturated moisture absortion rate and their regression coefficients were 0.9 and 0.88, respectively. This means that the knitted and woven fabric design technology for retaining good wicking and drying properties of the fabrics with thin fabric thickness is very important for obtaining high functional wear comfort fabrics. In addition, wicking and drying properties of the fabrics made of different fiber materials and with different yarns and fabric structures showed different results according to the measuring methods.

• Journal of Fashion Business
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• v.10 no.4
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• pp.1-15
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• 2006

The purpose of this study was to analyze the image perception of dress shirts according to perceiver's residency and shirts style, and to investigate the shirts preference according to style of dress shirts, and to find out the men's aesthetics consciousness for shirts, and to analyze between the image perception and the usage of mass-media, for developing the possibility & strategy of the dress shirts market in men's wear market for the apparel marketers and manufactures. For this study, the data obtained from 321 respondents were analyzed by descriptive statistics, Pearson's simple correlation, ANOVA. The results from the study were as follow ; The 6 stimuli for image perception rated on 5 point Likert-type scales in the 12 features were evaluated by perceivers. By the best 3 features abstracted, shirts style concepts were decided such as, Basic style by the best 3 features of the first stimulus, and Soft style by the best 3 features of the second stimulus, and Sophisticate style by the best 3 features of the third stimulus, and Modern casual style by the best 3 features of the fourth stimulus, and Modern mannish style by the best 3 features of the fifth stimulus, and Trendy style by the best 3 features of the sixth stimulus. The modern casual style was estimated highly by respondents in Daejon. The respondents in Seoul prfered the basic style to other style. There were significant differences in evaluating between preferences of shirts style and pattern. Of the 82 respondents(26.8%) with the preference of bold london stripe, the 52 respondents estimated Modern casual style in bold london stripe. The fashion consciousness of the respondents in Seoul was estimated higher than in Daejon. But, the respondents in Daejon in the consciousness for the coordination knit cardigan and V zone was estimated higher than in Seoul. Also, the 31 respondents with the preference of Sophisticate style were the highest in fashion consciousness. The respondents estimated that the first important thing in buying dress shirts is 'Design(41.4%). and next is quality(17.8%). Results revealed that Daks ranked best brand (13.7%), and Renoma ranked best two brand (6,5%). And, the 35.5% respondents estimated that the first important information which influenced on buying dress shirts was the store display, next was internet(15.9%). Finally, I propose that the best strategy for men with low fashion consciousness is to upgrade salesmen' coordination technic and fabric knowledge, and store management with story attracting customers.

• 전자공학회논문지 IE
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• v.49 no.1
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• pp.12-17
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• 2012

Fast development of ubiquitous technology prompted the broadening of the related application area. Application of ubiquitous techniques and system into the construction sites may give us many benefits. There are always a lot of hazard situations in construction sites, and the falling is known to have the high accident rate. To prevent the falling, there has been a lot of efforts including safety education and use of safety gears. In this study, we designed, fabricated and tested a system that can monitor the worker's safety and location informations in real time by using the wireless technology of TOA and RSSI. We used ATmegal28 that is popular in the industrial equipments as MCU and NanoPan 5357 module from Nanotron and CC2500 chipset from TI for radio circuits. We also used 3-axis accelerometer and pressure MEMS sensors to obtain the environmental information, and therefore to aquire the informations of the worker's movement and altitude. We used Labview software from National Instrument to monitor and control the system. We developed the system to send the warning alarms to the server operator and the workers when the workers in the danger zone did not wear the safety hook.

• Journal of the Korea Fashion and Costume Design Association
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• v.8 no.1
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• pp.81-96
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• 2006

This study aimed to investigate the sociocultural phenomena which affected to clothing change in 1650-1900 and to examine the features of men's necktie in the western art. For this study, information about historic neckwear is obtained from the visual evidence of painted or engraved portraits, contemporary written sources. The covered area of this study was Europe mainly England and France. For this process, research steps were as follows : 1. Investigating the sociocultural phenomena which affect to clothing change through 1650-1900 and analysis of men's clothing and appearance. 2. Finding the changing characteristics of neckties including it's different types, shapes, knots, colors and materials and analyzing similarities and differences of neckties by the times. 3. Examining necktie as one of important and representative icons of male gender identity. The results of the study was as follows: 1. In 1660-1900, men's fashion was simplified in color and detail due to the influence of practical Puritanism and matured civil culture. And British men's fashion spreaded throughout whole European countries and get popularity. 2. In 1650-1720, there were band, cravat and steinkirk. And expecially cravatier, a expert custodian of cravats, was appeared in that period. In 1720-1800, there were stock, solitaire and cravat. In 1800-1850, neckwear were popularized and got various sizes and types up to shape and size of chemise collars. Black stock, scarf cravat and shawl cravat were popular and terms of 'necktie' were used for an certain neckcloth shape. And abundant literature for necktie were published thanks to the development of printing technology in that period. In 1851-1900, the leady-made neckties were spreaded and there were changes in shape, length, knot of necktie up to V-zone formed with shirt's collars and vest types. Neckwear was gradually evolving through four distinct styles, bow tie, scarf or neckerchief, Ascot and four-in-hand. 3. After the mid-l7th Century, as civil culture matured and splendid and extravagant colorful men's wear disappeared, British men's fashion spreaded throughout whole European countries and got popularity. The necktie become an essential ornamental accessory of men's fashion and one of important and representative icons of male gender identity.