• Title/Summary/Keyword: Wear characteristic

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A Study on the Ethnic Minimalism Expressed in Modern Fashion - Comparing with Minimalism - (현대 복식에 나타난 에스닉 미니멀리즘에 관한 연구 - 미니멀리즘(minimalism)과의 비교 고찰을 통하여 -)

  • Chae, Hye-Sook;Chae, Keum-Suk
    • Journal of the Korean Society of Costume
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    • v.58 no.3
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    • pp.63-78
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    • 2008
  • Since 1960, minimalism has been one of the fashion phenomenon and turned out in many different ways. After postmodernism which contains negotiation and pluralism, appeared in 1980, there was a new wave of post minimalism that inherited 1960's minimalism. Minimal style which come out of 60's fashion, is marked by simplicity, minimal expression, and monochrome color, and it shows up simple style with no decoration. It opened up a young fashion period, and we saw minimal style in sports wear which utilized simplicity and function with spread of sports in the 70's. And also since 1980, Post-Modern widely influenced the idea about modern culture as well as complicated clothes getting rid of fixed concept, seeking to break the boundary between culture and life which were seek in fashion and personality as well as various characteristic, Accordingly in different ages, The style and image were borrowed from different culture and natural environment mixing the image, cultural phenomena like these appearing in complexity and expression, variety and possibility of new vision was expanded. Since 1980, Fashion has become more gradually diversity, high classed, required of each individuality. The phenomenon of fashion reappearance which was influenced by minimalism is continued to 2000. The Oriental style fashion is still attracted, so The new term "Ethic Minimalism" has appeared along with the trends which is put together. Therefore the purpose of this study is to search the concept and the characteristics of ethnic minimalism, to consider the relationship between minimalism and ethnic minimalism, and reveal the characteristic of ethnic minimalism happened to modern fashion. The study method went through literature research and practice research. The range of this study is oriental fashion spanning of from 1960 to current day. Photo records from this period show well the spirit of the oriental and the personality of minimalism. The oriental representative designer and western representative designer are centered Consequently, The formative characteristics of ethnic minimalism are simple, pure, unbalanced free style and representing the phenomena of compromise, blending oriental and western fashion. Structually, Elements of space and plane are emphasized, colors are restricted, and materials are composed mainly of natural fiber. So, minimalism based on simplicity combined with a structure of oriental spiritual depth and space, It could be called ethnic minimalism as a rational fashion.

A study on the asperity degradation of rock joint surfaces using rock-like material specimens (유사 암석 시편을 사용한 암석 절리면 돌출부 손상 연구)

  • Hong, Eun-Soo;Kwon, Tae-Hyuk;Cho, Gye-Chun
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.11 no.3
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    • pp.303-314
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    • 2009
  • Image analyses for sheared joint specimens are performed to study asperity degradation characteristics with respect to the roughness mobilization of rock joints. Four different types of joint specimens, which are made of high-strength gypsum materials, are prepared by replicating the three-dimensional roughness of rock joints. About twenty jointed rock shear tests are performed at various normal stress levels. The characteristic and scale of asperity degradation on the sheared joint specimens are analyzed using the digital image analysis technique. The results show that the asperity degradation characteristic mainly depends on the normal stress level and can be defined by asperity failure and wear. The asperity degradation develops significantly around the peak shear displacement and the average amount of degraded asperities remains constant with further displacement because of new degradation of small scale asperities. The shear strength results using high-strength gypsum materials can not fully represent physical properties of each mineral particles of asperities on the natural rock joint surface. However the results of this quantitative estimation for the relationship between the peak shear displacement and the asperity degradation suggest that the characterization of asperity degradation provides an important insight into mechanical characteristics and shear models of rock joints.

A Study on the Somatotype Characteristics of Korean Adult Women: A Comparison between the Data of the 5th Anthropometry of Size Korea and 6th Anthropometry of Size Korea

  • Yi, Kyong-Hwa
    • Journal of the Ergonomics Society of Korea
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    • v.31 no.1
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    • pp.237-245
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    • 2012
  • Objective: The aim of the study is to analyze female adult's body shape characteristics and to provide the basic information for clothing manufacturing. Background: The comparative study among the age groups is very fundamental to understand the body characteristics of each subjects group. Therefore, comparison of body measurements in age groups was applied in this study. Method: The study was fulfilled by the comparison between the data of the $5^{th}$ Anthropometry of Size Korea (2004) and the $6^{th}$ Anthropometry of Size Korea(2010). The subjects were 2,213 female adults aged 20~59 of the 5th Size Korea anthropometric survey and 2,025 female adults aged 20~59 of the 6th Size Korea anthropometric survey. Results: The differences indicated the decreased values in widths, depths, girths regarding the torso region and BMI. "Head height to Stature ratio" decreased significantly in the 6th data, on the other hand, "Crotch height to Stature ratio" increased in the 6th data. Through the distribution characteristic of the age groups by Stature groups, it was convinced that 160cm stature group is the most frequent among all age groups of the 6th Size Korea. Conclusion: As a summary, the meaningful differences were showed between the 5th anthropometric data and the 6th data. According to the 6th Size Korea, the distribution tendency of obesity is very similar to the 5th Size Korea data. But the percentage of obese women declined significantly. Application: These findings from the study can be utilized women's wear design and construction that reflect body characteristics.

SEMIDIRECT RESIN INLAY RESTORATION OF POSTERIOR TEETH (반직접법 레진 인레이를 이용한 구치부의 수복)

  • Han, Mi-Ran;Kim, Jong-Soo;Kim, Yong-Kee
    • Journal of the korean academy of Pediatric Dentistry
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    • v.26 no.3
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    • pp.479-485
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    • 1999
  • Materials for posterior teeth includes amalgam, gold inlay and composite resin inlay. Amalgam and gold inlay have unsatisfyine esthetics. And because they simply obturate the cavity preparation, they do not strengthen the remaining tooth structure. Posterior composite resin has become established in recent years. However, its polymerization shrinkage and insufficient wear resistance were the most undesirable characteristic. The physical and mechanical properties of the composite resin inlay are further improved through heat treatment in an oven. The major part of polymerization contraction of the resin inlay takes place be fore cementation, and possible gap formation is only due to shrinkage of the thin layer of resin cement. With the semidirect technique, the inlay material is placed directly in the prepared tooth, and the primary polymerization is made by light activation with a handhold curing unit. Additional curing may take place extraorally with use of different curing ovens. It provides the patient with the benefits of luted restorations without the procedure of indirect lab-made inlay. I report three successfully treated cases by semidirect resin inlay technique. Entire clinical steps are described in detail with some discussions on the outcome.

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A Study on Feed Rate Characteristics of Motor-driven Cylinder Lubricator with Electronic Control Quill in a Large Two-stroke Diesel Engine (대형 2행정 디젤기관에 있어서 전자제어 퀼 부착 모터구동 실린더 주유기의 송출유량 특성에 관한 연구)

  • Bae, Myung-Whan;Jung, Hwa;Jung, Yeun-Hak;Kim, In-Deok;Kang, Chang-Ho
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.6
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    • pp.1-8
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    • 2007
  • Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke marine diesel engine is of great economic importance. In Korea, authors first developed a motor-driven cylinder lubricator for a Wartsila Switzerland large two-stroke diesel engine. The characteristic of the developed product is that can control automatically the oil feed rate with a load fluctuation by the motor drive and the offset cam. For manufacturing the reliable and useful products, however, it is necessary to investigate further characteristics and to improve performances as a cylinder lubricator. In this study, the effects of pump motor speed, plunger stroke and cylinder back pressure on oil feed rate, maximum discharge and delivery pressures are experimentally investigated by using the electronically controlled quill injection system and distributer in the developed cylinder lubricator. It is found that the oil feed rates of electronic control and mechanical type quills with the in-cylinder back pressure are differently characterized by the role of accumulator, the viscous resistance of contact area, etc. It can be also shown that the maximum discharge pressure of the electronic control quill is lower than the mechanical type one but the maximum discharge pressure difference of two types decreased as plunger stroke is small, and the maximum delivery pressures of two types increased as plunger stroke, motor speed and back pressure are elevated but the maximum delivery pressure of mechanical type is higher than the one of electronic control type.

Stick-slip Characteristics of Magnetorheological Elastomer under Magnetic Fields (자기장에 따른 자기유변탄성체의 스틱 슬립 현상 연구)

  • Lian, Chenglong;Lee, Kwang-Hee;Kim, Cheol-Hyun;Lee, Chul-Hee;Choi, Jong Myoung
    • Tribology and Lubricants
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    • v.31 no.1
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    • pp.6-12
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    • 2015
  • This paper investigates the stick-slip characteristic of magnetorheological elastomer (MRE) between an aluminum plate and the surface of the MRE. MRE is a smart material and it can change its mechanical behavior with the interior iron particles under the influence of an applied magnetic field. Stick-slip is a movement of two surfaces relative to each other that proceeds as a series of jerks caused by alternate sticking from friction and sliding when the friction is overcome by an applied force. This special tribology phenomenon can lead to unnecessary wear, vibration, noise, and reduced service life of work piece. The stick-slip phenomenon is avoided as far as possible in the field of mechanical engineering. As this phenomenon is a function of material property, applied load, and velocity, it can be controlled using the characteristics of MRE. MRE as a soft smart material, whose mechanical properties such as modulus and stiffness can be changed via the strength of an external magnetic field, has been widely studied as a prospective replacement for general rubber in the mechanical domain. In this study, friction force is measured under different loads, speed, and magnetic field strength. From the test results, it is confirmed that the stick-slip phenomenon can be minimized under optimum conditions and can be applied in various mechanical components.

Friction Assessment of Canola Oil on Contact Bearing Materials

  • Okechukwu, Nicholas Nnaemeka;Byun, JaeYoung;Kim, JongSoon;Park, JongMin;Kwon, SoonGoo;Chung, SungWon;Kwon, SoonHong;Choi, WonSik
    • Tribology and Lubricants
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    • v.36 no.1
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    • pp.11-17
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    • 2020
  • In manufacturing operations, oil plays a crucial role in reducing friction and wear among interacting surfaces at varying velocities, loads, and temperature. Hydrocarbon oil is considered the origin of lubrication oils. However, this base oil has been limited in its use as it is a principal cause of pollution. This research focuses on identifying a biodegradable base oil lubricant that possesses a stable coefficient of friction and viscosity with temperature. Friction analysis is conducted by employing a pin on a disk tribotester with a fixed load of 10 N at varying sliding speeds ranging from 0.06 m/s to 0.34 m/s. Oil viscosity analysis is perfomed at room temperature by using a rotary viscometer. Tests are performed using canola oil and paraffin oil as lubricants. The results indicate that the viscosity of canola oil is more efficient than paraffin oil. The non-dimensional characteristic number according to the Stribeck curve reveals an elastohydrodynamic lubrication regime with canola oil lubrication. A comparison of both lubricants reveals that, the friction efficiency of canola oil and paraffin oil does not differ considerably. However, the friction in canola oil is observed to decrease more than that in paraffin oil at an elevated sliding speed. The tests confirm that canola oil is potent in minimizing the friction coefficient of SCM440 bodies interacting with one another as well as acted upon by load.

A Study on the Late 19th century Children's Costumes and Games of Genre Paintings by Jungeun Kim (19세기말 풍속화가 기산 김준근이 그린 삽화 속 어린이 놀이문화와 복식에 관한 연구)

  • Choi, Eunjoo
    • Fashion & Textile Research Journal
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    • v.18 no.3
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    • pp.289-300
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    • 2016
  • This study surveys children's costumes and games from the 11 Genre paintings by Junkeun Kim in the book "Korean Games(Stewart Culin 1858-1929)". The character of the general dress-costumes, games and the culture of life from the late $19^{th}$ century in genre painting of Junkeun Kim are as follows. The study results on the games are as follow. The boy's games are kite-flying, spinning tops, playing shuttlecock with the feet, blindman's buff, yut("Four-Stick Game"). Girl's games are seesaw with board, blindman's buff, marbles. Combined games are mount shoulder, sledge, tightrope walking for men with boy. The strengthen one's body type were seesaw with board, tightrope walking, the compete score type were playing shuttlecock with the feet, marbles and the multi complex type were yut("Four-Stick Game"), kite-flying. Through genre painting in the $19^{th}$ century we know a boy's 'Jeogori 'and 'Ba-ji' were similar to a modern man's and boy's 'Hanbok' with a traditional method of wearing. We believe that the originality of a traditional costume was an unchangeable characteristic. Girl's 'Jeogori' and 'Chi-ma' changed in length and width, and method of wearing; however, the basic shape did not change. The analysis for artist's genre painting which was ordered by a foreigner and the late of $19^{th}$ century's children's costume and game of life culture is useful to match the counters and show how to wear a modern Korean costume used to understand the 'Hanbok' and establish a costume of life.

A Study of the Life Test of Hydraulic Pump Driving Gear Box for the Large Excavator (초대형 굴삭기용 유압펌프 구동 기어박스의 수명시험에 관한 연구)

  • Lee, Yong Bum
    • Journal of Advanced Marine Engineering and Technology
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    • v.39 no.3
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    • pp.211-216
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    • 2015
  • Large hydraulic excavator weighted 90 tons used the several pumps installed in parallel to use the hydraulic pump driving gearbox to improve fuel consumption by improving the energy efficiency of the hydraulic system. Gearbox connected to hydraulic pump supply the mechanical output to the high pressure and low pressure pump to be supplied by torque and rotation, which are the mechanical power, through a input shaft connected to large size engine of the excavator. So, gearbox connected to hydraulic pump is same as main artery in the human body and is required long life because it operates the hydraulic pump continuously during operating the engine. This study had used oil contamination analysis method to check the wear characteristics of the gearbox and frequency response characteristic analysis method to check the failure of the teeth failures of gearbox, while the test equipment adopted by the electrical feedback method to reduce the energy consumption was operating for the life assessment, in which the required power was 600 kW input power.

A Study on Effect of Quill Accumulator upon Performance of Motor-driven Cylinder Lubricator in a Large Two-stroke Diesel Engine (대형 2행정 디젤기관용 모터구동 실린더 주유기의 성능에 미치는 퀼 어큐뮬레이터의 영향에 관한 연구)

  • Bae, Myung-Whan;Ok, Hyun-Jin;Jung, Hwa
    • Transactions of the Korean Society of Automotive Engineers
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    • v.15 no.2
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    • pp.115-125
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    • 2007
  • Minimizing the cylinder wear and the consumption rate of cylinder oil in a large two-stroke marine diesel engine is of great economic importance. In Korea, a motor-driven cylinder lubricator for a large two-stroke marine diesel engine manufactured by $W{\ddot{a}}rtsil{\ddot{a}}$ Switzerland Co., Ltd. was first developed by authors through the joint research of industry-university in 2002. The characteristic of the developed product is that can control automatically the oil feed rate to a load fluctuation by the motor drive and the offset cam. The performance of the product is not also inferior to the conventional one. For manufacturing the reliable and useful products, however, it is necessary to investigate further characteristics and improve the performance of a cylinder lubricator. In this study, the effect of quill with and without accumulator on maximum discharge pressure, delivery delay duration and oil feed rate relative to motor revolution speed using plunger stroke as a parameter is experimentally investigated by using the developed cylinder lubricator. It is found that the maximum discharge pressure with accumulator is higher than that of no accumulator as plunger stroke and motor revolution speed are elevated, and the delivery delay duration with accumulator is shorter than that of no accumulator as plunger stroke and motor revolution speed are increased. Also, oil feed rate with accumulator is less than that of no accumulator except for a plunger stroke of 2 mm as plunger stroke and motor revolution speed are raised.