• Title/Summary/Keyword: Wear Theory

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The Text Analysis of Plasticity Expressed in the Modern Art to Wear (Part I) - Focused on the West Art Works since 1980s - (현대 예술의상에 표현된 조형성의 텍스트 분석 (제1보) - 1980년대 이후 서구작가 작품을 중심으로 -)

  • Seo Seung Mi;Yang Sook Hi
    • Journal of the Korean Society of Clothing and Textiles
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    • v.29 no.6
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    • pp.793-804
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    • 2005
  • The new paradigm of the 21st century demand an openly different world of formative ideologies in respect to art and design. The purpose of this study is focused on trying to comprehend aesthetic essence of clothing as an, with the investigation of artistic theories manifested by art philosophers. Art to Wear was categorized into style to understand its artistic meaning as well as to analyze its character. Upon the foundation of semiotics theory, the feature of Art to Wear and its analysis category were argued in the context of Charles Morris three dimension of semiotics analysis. The conclusion to the research is like so. The feature and analysis category of Art to Wear upon a semiotics perspective was divided into syntactic dimension, semantic dimension and pragmatic dimension. The analytical categorization upon the perspective of syntactic dimension fell into the category of topology, shape and color. The semantic dimension of Art to Wear was divided into categories of denotation and connotation. In addition, the pragmatic dimension of Art to Wear analytical categorization was divided into a delivering function and common function.

Wear Debris Concentration Measurement by Laser Beam Attenuation (광감쇄를 이용한 마모입자의 농도 측정)

  • 강기호;손정영;전형욱;윤의성;안효석
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 1990.11a
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    • pp.58-62
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    • 1990
  • The size and concentration of wear debris in lubricating oil often reveal the operating condition of the rotating machinery. To evaluate the possible application of light attenuation measurement for the estimation of wear debris concentration in the lubricating oil, the light transmittance through the lubricating oil cell contaminated with various concentrations of diatomite particles was measured, the attenuation coefficient was estimated from the transmittance measurement and the coefficients were compared with those obtained from the scattering theory. The comparision showed good agreements between them. It is also noted that the experimentally determined attenuation coefficient showed almost linear relation with particle weight concentrations for the concentrations within the range of 2000 ppm. For the case of 0 ppm weight concentration of diatomite particles in the lubricating oil cell, the thickness of the cell required to give $100 \mu W$ light attenuation is 7.75 mm. This result indicates that the light attenuation method will be one of the possible candidates of machine failure diagnostic sensors for the estimation of wear debris concentration in the lubricating oil.

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Wear Debris Coacentration Measurement by Laser Beam Attenuation (광감쇄를 이용한 마모입자의 농도 측정)

  • 강기호;손정영;전형욱;윤의성;안효석
    • Tribology and Lubricants
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    • v.6 no.2
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    • pp.94-98
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    • 1990
  • The size and concentration of wear debris in lubricating oil often reveal the operating condition of the rotating machinery. To evaluate the possible application of light attenuation measurement for the estimation of wear debris concentration in the lubricating oil, the light transmittance through the lubricating oil cell contaminated with various concentrations of diatomire particles was measured, the attenuation coefficient was estimated from the transmittance measurement and the coefficients were compared with those obtained from the scattering theory. The comparision showed good agreements between them. It is also noted that the experimentally determined attenuation coefficient showed almost linear relation with particle weight coucentrations for the concentrations within the range of 2000 ppm. For the case of 0 ppm weight concentration of diatomire particles in the lubricating oil cell, the thickness of the cell required to give $100 \muW$ light attenuation is 7.75 mm. This result indicates that the light attenuation method will be one of the possible candidates of machine failure diagnostic sensors for the estimation of wear debris concentration in the lubricating oil.

Mechanism of aging and prevention (노화의 기전과 예방)

  • Kim, Jay Sik
    • IMMUNE NETWORK
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    • v.1 no.2
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    • pp.104-108
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    • 2001
  • Aging is a senescence and defined as a normal physiologic and structural alterations in almost all organ systems with age. As Leonard Hayflick, one of the first gerontologists to propose a theory of biologic aging, indicated that a theory of aging or longevity satisfies the changes of above conditions to be universal, progressive, intrinsic and deleterious. Although a number of theories have been proposed, it is now clear that cell aging (cell senescence) is multifactorial. No single mechanism can account for the many varied manifestations of biological aging. Many theories have been proposed in attempt to understand and explain the process of aging. Aging is effected in individual by genetic factors, diet, social conditions, and the occurrence of age-related diseases as diabetes, hypertension, and arthritis. It involves an endogenous molecular program of cellular senescence as well as continuous exposure throughout life to adverse exogenous influences, leading to progressive infringement on the cell's survivability so called wear and tear. So we could say the basic mechanism of aging depends on the irreversible and universal processes at cellular and molecular level. The immediate cause of these changes is probably an interference in the function of cell's macromolecules-DNA, RNA, and cell proteins-and in the flow of information between these macromolecules. The crucial questions, unanswered at present, concerns what causes these changes in truth. Common theories of aging are able to classify as followings for the easy comprehension. 1. Biological, 1) molecular theories - a. error theory, b. programmed aging theory, c. somatic mutation theory, d. transcription theory, e. run-out-of program theory, 2) cellular theories - a. wear and tear theory, b. cross-link theory, c. clinker theory, d. free radical theory, e. waste product theory, 3) system level theory-a. immunologic/autoimmune theory, 4) others - a. telomere theory, b. rate of living theory, c. stress theory, etc. Prevention of aging is theoretically depending on the cause or theory of aging. However no single theory is available and no definite method of delaying the aging process is possible by this moment. The most popular action is anti-oxidant therapy using vitamin E and C, melatonin and DHEA, etc. Another proposal for the reverse of life-span is TCP-17 and IL-16 administration from the mouse bone marrow B cell line study for the immunoglobulin VDJ rearrangement with RAG-1 and RAG-2. Recently conclusional suggestion for the extending of maximum life-span thought to be the calory restriction.

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Mixed Lubrication Analysis of Cam/Tappet Interface on the Direct Acting Type Valvetrain System

  • Cho, Myung-Rae;Shin, Heung-Ju;Han, Dong-Chul
    • Journal of Mechanical Science and Technology
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    • v.15 no.6
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    • pp.685-692
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    • 2001
  • This paper reports on the mixed lubrication characteristics between the cam and the tappet contact surface of direct acting type valve train systems. First, the dynamic characteristics are solved by using the lumped mass method to determine the load conditions at the contact point. Then, the minimum oil film thickness is calculated with consideration of elastohydrodynamic line contact theory and the friction force is obtained by using the mixed lubrication model which separates the hydrodynamic and the boundary friction. Finally, the average surface temperatures are calculated by using the flash temperature theory. The results show that, there are some peaks in the friction force due to the asperity contact friction, and flash temperature at the position of minimum oil film thickness. It is thought that there is a relationship between the surface temperature and cam surface wear, and therefore, the analysis on the worn cam profile has been performed.

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Information Sources of Reference Used by Male College Students for Casual Wear Purchase Decisions

  • Shin, Su-Yun
    • The International Journal of Costume Culture
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    • v.2 no.1
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    • pp.77-86
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    • 1999
  • This study was designed to identify the information sources of reference used by male college students. Theoretical framework is based upon social comparison theory, reference group theory, and Kotler's model of personal and non-personal sources of reference. The subjects were 287 male college students. The questionnaire were distributed to the school area and the commercial area such as Shinchon, Myung-Dong, and Apkujung-Dong in Seoul. Means, standard deviation, frequency, T-test, one-way ANOVA, and Duncan's multiple range test were applied for the analyses of data. The result of hyporthesis 1 showed that male college student utilize personal and non-personal sources of reference indiscriminately. The result of hypothesis 2 showed that male college students consult the socially high-proximal group such as a girl friend(a lover) and mother most actively. The result of hypothesis 3 found that male college students use position media most actively, especially in-store displays, followed by print media and broadcast media.

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Spherical Particles Formation in Lubricated Sliding Contact -Micro-explosion due to the Thermally-activated Wear Process-

  • Kwon, O.K.
    • Tribology and Lubricants
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    • v.11 no.5
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    • pp.1-9
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    • 1995
  • The mechanism of various spherical particles formation from wide range of tribo-systerns is suggested and deduced by the action of micro-explosion on the basis of the thermally-activated wear theory, in which the flash temperature at contact could be reached clearly upto the material molten temperature due to the secondary activation energy from the exothermic reactions involving lubricant thermo-decomposition, metals oxidation, hydrogen reactions and other possible complex thermo-reactions at the contacts. Various shapes of spherical particles generated from the tribosystem can be explained by the toroidal action of micro-explosion accompanied with the complex thermo-chemical reactions at the contact surfaces or sub-surfaces.

A Study on the Wear of Rail by Fracture Mechanics (파괴역학을 이용한 차륜과 레일의 마모에 관한 연구)

  • 구병춘
    • Proceedings of the KSR Conference
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    • 1998.05a
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    • pp.315-322
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    • 1998
  • A two dimensional elasto-plastic finite element program taking into account contact between crack surfaces if developed in order to analyze subsurface cracking in rolling contact. But the friction between upper and lower surface of the crack is not considered. Under the assumptions of small deformation and small displacement, the incremental theory of plasticity is used to describe plastic deformation. J-integral is computed as the applied Hertzian load slides over the surface with friction. J-integral is correlated with wear rate of the rail. The propagation rate of the right tip of the surface crack is fast by 45% than that of the left side.

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Study on Wear of Journal Bearings during Start-up and Coast-down Cycles of a Motoring Engine - I. Theory and Analysis Procedure (모터링 엔진의 시동 사이클 및 시동 정지 사이클에서 저어널베어링의 마모 연구 − I. 이론 및 해석 절차)

  • Chun, Sang Myung
    • Tribology and Lubricants
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    • v.31 no.3
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    • pp.109-124
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    • 2015
  • This paper presents a wear analysis procedure for the journal bearings on a stripped-down single-cylinder engine during start-up and coast-down by motoring. A journal bearing is in the mixed elastohydrodynamic (EHL) lubrication region when the shaft speed is less than the corresponding lift-off speed. Below the lift-off speed, a wear scar can form on bearing surfaces. In part 1 of this paper, we develop the appropriate formulations and the calculation procedure for the analysis. Specifically, we formulate an equation for modified film thickness in a journal bearing considering the additional wear volume. In order to obtain the modified specific wear rate induced by the modified Archard’s wear coefficient, we utilized the extended non-dimensional diagram for the specific wear rate, k, the fractional film defect coefficient, Ψ and the asperity load sharing factor, γ2. This asperity load sharing factor is newly calculated by setting the Zhao-Maietta-Chang (ZMC) asperity contact pressure equation coupled with the central film thickness equation derived by using the ZMC asperity contact model equal to the modified central contact pressure derived by using the central (or maximum) contact pressure at the dry rough line-contact configuration. We can use the procedure introduced in this paper to determine the lifetime (or longterm) linear wear in radial journal bearings that is a result of repeated stop-start cycles.

A Study on the Origin of Clothing (의복(衣服)의 기원(起源)에 대한 연구(硏究) - 선사(先史) 시대(時代)를 중심(中心)으로 -)

  • Lee, Ran-Hee
    • Journal of the Korean Society of Costume
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    • v.6
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    • pp.145-160
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    • 1982
  • Wearing a clothes in human living is very rightful and reasonable things. And it's also the necessaries of living. So now, I want look around about origin of clothes from the prehistorical age, how they start and why they need to wear a clothes. As human culture is unknown origin, human clothes origin is also unknown origin, too. So many different people made unlike story about that, and it is very difficult to say correct birth of clothes. It must be reflection by a time, by a place, by a mankind, until this days, the history of human progress is $2,000,000{\sim}3,000,000$ years. And from after the "Old Adam" man understand what is shame and disgrace, so that made them cover of their private parts, also it is a motive of human clothes. Since after pass a long time, the earth has many changes as it were weather, and for take care of human body from cold, people start make clothes and it's a second object of wearing a clothes. And third object of wearing clothes is after opportunity of development human culture, people desire for an aesthetic sence and for full-fill that feeling they start make a beautiful clothes with accessories and it is motive and a purpose of a human start wear a clothes. So I can say, for origin birth of clothes is 1. Protect of human body. 1) be adapted for different weather and different circumstance. 2) take care self from outside injurg. 2. Decorate for aesthetic sence. 1) Theory of Amulets. 2) Theory of symbolism. 3) Theory of Sex attraction. 4) Aesthetic Theory. 5) Theory of chastity. 6) Multi-theory And material for clothes they made from natural wilds like leaves, fur, skin of wood. skin of fishes and feather etc. But after develop of human knowledge people invent fiber, and use a knitted goods and woven stuff also first of all. They start use those kind that they just cover of their private parts as a belt and astring with leaves and a beast skins. But until this days it's taken big development with human knowledge and most important influence of develop was weather. So modern clothes for present days, must care with. physicology, preservation of health, living activity, dressing, morals, and etiquette etc.

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