• 제목/요약/키워드: similar material

검색결과 3,185건 처리시간 0.03초

An Experimental Study on Crack Growth in Rock-like Material under Monotinic and Cyclic Loading (단조증가 및 반복하중 하에서 모사 암석 시료의 균열 성장에 관한 실험적 연구)

  • Ko, Tae-Young;Lee, Seung-Cheol;Kim, Dong-Keun;Choi, Young-Tae
    • Tunnel and Underground Space
    • /
    • 제21권4호
    • /
    • pp.307-319
    • /
    • 2011
  • Cyclic loading due to traffic, excavation and blasting causes microcrack growth in rocks over long period of time, and this type of loading often causes rock to fail at a lower stress than its monotonically determined strength. Thus, the crack growth and coalescence under cyclic loading are important for the long-term stability problems. In this research, experiments using gypsum as a model material for rock are carried out to investigate crack propagation and coalescence under monotonic and cyclic loading. Both monotonic and cyclic tests have a similar wing crack initiation position, wing crack initiation angle, cracking sequence and coalescence type. Three types of crack coalescence were observed; Type I, II and III. Type I coalescence occurs due to a shear crack and Type II coalescence occurs through one wing or tension crack. For Type III, coalescence occurs through two wing or tension cracks. Fatigue cracks appear in cyclic tests. Two types of fatigue crack initiation directions, coplanar and horizontal directions, are observed.

A Study on the Shroud around Kwanju and Chonnam Area (광주.전남지역 수의에 관한 실태 조사)

  • Yim, Linn;Kim, Yong-Seo
    • Journal of the Korean Society of Costume
    • /
    • 제51권2호
    • /
    • pp.93-103
    • /
    • 2001
  • This Study shows local characters, meaning, value and others (kind, function, material, shape, name) on Shroud through documents and fact-finding survey. In Shroud′s kind and function, Shroud of Kwangju Area is similar with one of Youngsan-river Area, while Sumjin-river Area and Coastal Area, each has its own character due to difference of Burial Culture. In Shroud′s Material, hemp cloth, white cotton cloth and calico, have been well-used in Kwangju and Youngsan-river Area, while silk has used in Sumjin-river and Coastal Area. Shroud′s color has followed Natural color. In Shroud′s shape, Male Jeoksam, Female Trousers, Um, Myokmok, Aksoo, Bib have their local characters. They are reformed in Kwangju Area and Youngsan-river Area. Jeoksam in Coastal Area, Female Trousers in Sumjin-river Area. Um in Coastal Area and Myokmok in Sumjin-river Area, have its unique character. In Shroud′s name, Shroud has widely been called "Dead Clothes", and called "Blind Clothes", "Munnyung Clothes" some areas. In Sumjin-river Area, Summer Jacket has been failed "Deungjigae", Dango called "Ddangjungwee". In Coastal Area, Myokmok and Aksoo have been called "Face Cover" and "Hands Cover", Shroud′s local characters have been caused by Next World, which has reflected local natural environment and cultural features. Next World is so abstract that it can not be expressed well, while Reality is clearly divided into dual spaces : Real World, Next World. Comprehension on Next World, helps harmonize recent values with Shroud meaning and prevents Shroud from standardization and transformation.

  • PDF

A Suggestion for the Development of Cultural Products through the Analysis of the Significance Patchwork Wapping Colthes (Jogakbo) (조각보 의미 분석을 통한 문화상품 개발 방안)

  • Kim, Yeo-Kyung;Hong, Na-Young
    • Journal of the Korean Society of Costume
    • /
    • 제59권3호
    • /
    • pp.145-156
    • /
    • 2009
  • This study proposes the product development through an organic link with multi-faceted analysis on the archetype of traditional costumes culture. In order to find ways to develop cultural products, Jogakbo was selected, and the research result is as following. 1. Analysis on the types of Jogakbo products sold in the market shows that there are not only living, stationary, and fashion items, but also DIY packages. In terms of materials used, most of these Jogakbo products were made of fabric or mixture of different materials. These products displayed similar tendency by reflecting formative characteristics of Jogakbo. 2. This study analyzed the color, surface composition, material, manufacturing, and usage of Jogakbo. The rotor of Jogakbo is mostly composed of mono tone colors or Obangsac(five-element colors). The mono tone colors carries environmentally friendly meaning as it is using the natural color and Obangsac means harmony. Moreover, the surface composition of Jogakbo represents the expansion through connection and its material is also meaningful in that it is recycling. Manufacturing of Jogakbo has educational significance, fortune-wishing characteristics, decorative function, it also gives a gratification of handcraft. The usage of Jogakbo is a multi-(unctional article whose form is determined by an item that is held inside it. 3. Through the analysis on Jogakbo, this study presents the baby wear in relation to the ere-friendliness of colors, brooch sets using the surface composition, dresses using recycling fabric, children's educational instruments with educational significance, as well as multi-functional packages in regards to usage of Jogakbo.

How the museum architecture has been affected by the social shift to the plural society since 1990 (다원적 사회로의 변화가 뮤지엄 건축의 공간에 미친 영향에 관한 연구)

  • Ko, Jae-Min;Moon, Jung-Mook;Lim, Che-Zinn
    • Proceedings of the Korean Institute of Interior Design Conference
    • /
    • 한국실내디자인학회 2004년도 춘계학술발표대회 논문집
    • /
    • pp.116-122
    • /
    • 2004
  • Since the 18th century the museums in Europe have accepted the social demand of the publicity and have played a role of social education and it lasted to the present. Recently, the society began to change it's direction. It is from the Universalism to the Pluralism. The Universalism is due to democratic society after 'the Civil Revolution' and standardized social system after 'the Industrial Revolution' The Pluralism that starts with the decrease of the modern society is about the diversity and the activation of identity which has been disregarded since the Modernism. This study is to analyze and to clarify how the museum's educational environment which had begun since the 18th century has been changed since 1990 and how these are related to the social alteration from the Universalism to the Pluralism. As a result of this study, it was confirmed that there had been a simple circulation system and a unified spatial experience in the museum of Europe since 18th century to 1980's(phl) while there had been a complex circulation system and a diverse spatial experience in the museum of Europe after 1990's(ph2). These mean that the museum of phl gave a unified social education to the visitors and they came to have a similar knowledge and emotion after their seeing the exhibition material while the museums of 'ph2' gave a diverse one and the visitor came to have a different knowledge and emotion to the same exhibition material. The museum which gives a unified social education is to produce a unified thoughts of people and it is because the social direction is the Universalism. In addition to this, the museum of diverse social education is to produce people of diversity and it is related to the Pluralism.

  • PDF

Preliminary Study on Nonlinear Static Response Topology Optimization Using Equivalent Load (등가하중을 이용한 비선형 정적 응답 위상최적설계의 기초연구)

  • Lee, Hyun-Ah;Zeshan, Ahmad;Park, Gyung-Jin
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • 제34권12호
    • /
    • pp.1811-1820
    • /
    • 2010
  • Most components in the real world show nonlinear response. The nonlinearity may arise because of contact between the parts, nonlinear material, or large deformation of the components. Structural optimization considering nonlinearities is fairly expensive because sensitivity information is difficult to calculate. To overcome this difficulty, the equivalent load method was proposed for nonlinear response optimization. This method was originally developed for size and shape optimization. In this study, the equivalent load method is modified to perform topology optimization considering all kinds of nonlinearities. Equivalent load is defined as the load for linear analysis that generates the same response field as that for nonlinear analysis. A simple example demonstrates that results of the topology optimization using equivalent load are very similar to the numerical results. Nonlinear response topology optimization is performed with a practical example and the results are compared with those of conventional linear response topology optimization.

Differential Induction of PepTLP Expression via Complex Regulatory System against Fungal Infection, Wound, and Jasmonic Acid Treatment during Pre-and Post-Ripening of Nonclimacteric Pepper Fruit

  • Jeon, Woong-Bae;Kim, Kwang-Sang;Lee, Hyun-Hwa;Cheong, Soo-Jin;Cho, Song-Mi;Kim, Sun-Min;Pyo, Byoung-Sik;Kim, Ynung-Soon;Oh, Boung-Jun
    • The Plant Pathology Journal
    • /
    • 제20권4호
    • /
    • pp.258-263
    • /
    • 2004
  • Ripe fruit of pepper (Capsicum annuum) showed resistance to Colletotrichum gloeoporioides, but unripe fruit was susceptible. We previously isolated the PepTLP gene that induced in both unripe and ripe fruit by fungal infection and wound, and only in ripe fruit by jasmonic acid (JA) treatment. To examine further regulation of PepTLP, the action of specific agonist and antagonists of known signaling effector on the .PepTLP expression by fungal infection, wound, and JA was investigated. A similar dephosphorylation event negatively activated all the PepTLP expression in the ripe fruit by fungal infection, wound, and JA. The induction of PepTLP expression by wound is differentially regulated via phosphorylation and dephosphorylation step during pre- and post-ripening, respectively. In addition, the induction of PepTLP expression in the ripe fruit by wound and JA is differentially regulated via dephosphorylation and phosphorylation step, respectively. Only both wound and JA treatment has synergistic effect on the PepTLP expression in the unripe fruit. Both SA and JA treatments on the unripe fruit, and both wound or JA and SA on the ripe fruit could not do any effect on the expression of PepTLP. These results suggest that the induction of PepTLP expression is differentially regulated via complex regulatory system against fungal infection, wound, and JA treatment during pre- and post-ripening of pepper fruit.

Study on Tribological Characteristics of Machine Component in Boundary Lubrication (경계윤활에서 기계 부품 소재의 트라이볼로지적 특성에 관한 연구)

  • Kim, Myeong-Gu;Seo, Kuk-Jin;Nam, Jahyun;Kim, Dae-Eun
    • Tribology and Lubricants
    • /
    • 제35권6호
    • /
    • pp.356-361
    • /
    • 2019
  • The friction and wear between machine components directly influence the energy loss and failure in various machines. Therefore, there is always a demand for finding methods to reduce friction and wear. Of the possible methods, lubrication is a widely used method for reducing friction and wear. In the case of lubrication, it is important to analyze the tribological behavior in the boundary lubrication because most of friction and wear occurs in the boundary lubrication regime. Cast iron has been regarded as a good material for industrial applications due to the excellent mechanical properties and high productivity. Especially, nodular cast iron is a material that shows better mechanical properties and wear-resistance compared with cast iron due to inclusion of spheroidal graphite. In this work, we investigated the tribological characteristics of nodular cast iron with respect to different counter parts in boundary lubrication regime. Sliding tests were conducted with SUJ2, ZrO2, Si3N4 balls as counter parts using a pin-on-disk type tribotester. The results showed different friction and wear behaviors with different counter parts. The case of ZrO2 showed the lowest wear rate in specimen and no significant ball wear. In case of SUJ2, it showed similar wear rate with ZrO2 case in specimen and the highest friction coefficient. The case of Si3N4 showed the lowest friction coefficient, 33% lower than the case of SUJ2. It showed 16.9 times larger wear rate in specimen and 43% larger wear rate in ball compared to that of the SUJ2 case.

Effect of Distribution System Materials and Water Quality on Heterotrophic Plate Counts and Biofilm Proliferation

  • CHANG , YOUNG-CHEOL;JUNG, KWEON
    • Journal of Microbiology and Biotechnology
    • /
    • 제14권6호
    • /
    • pp.1114-1119
    • /
    • 2004
  • The biofilms on pipe walls in water distribution systems are of interest since they can lead to chlorine demand, coliform growth, pipe corrosion, and water taste and odor problems. As such, the study described in this paper is part of an AWWARF and Tampa Bay Water tailored collaboration project to determine the effect of blending different source waters on the water quality in various distribution systems. The project was based on 18 independent pilot distribution systems (PDS), each being fed by a different water blend (7 finished waters blended in different proportions). The source waters compared were groundwater, surface water, and brackish water, which were treated in a variety of pilot distribution systems, including reverse osmosis (RO) (desalination), both membrane and chemical softening, and ozonation-biological activated carbon (BAC), resulting in a total of 7 different finished waters. The observations from this study consistently demonstrated that unlined ductile iron was more heavily colonized by a biomass than galvanized steel, lined ductile iron, and PVC (in that order) and that the fixed biomass accumulation was more influenced by the nature of the supporting material than by the water quality (including the secondary residual levels). However, although the bulk liquid water cultivable bacterial counts (i.e. heterotrophic plate counts or HPCs) did not increase with a greater biofilm accumulation, the results also suggested that high HPCs corresponded to a low disinfectant residual more than a high biofilm inventory. Furthermore, temperature was found to affect the biofilms, plus the AOC was important when the residual was between 0.6 and 2.0 mg $Cl_2/l$. An additional aspect of the current study was that the potential of the exoproteolytic activity (PEPA) technique was used along with a traditional so-called destructive technique in which the biofilm was scrapped off the coupon surface, resuspended, and cultivated on an R2A agar. Both techniques indicated similar trends and relative comparisons among the PDSs, yet the culturable biofilm values for the traditional method were several orders of magnitude lower than the PEPA values.

Effects of Diverse Water Pipe Materials on Bacterial Communities and Water Quality in the Annular Reactor

  • Jang, Hyun-Jung;Choi, Young-June;Ka, Jong-Ok
    • Journal of Microbiology and Biotechnology
    • /
    • 제21권2호
    • /
    • pp.115-123
    • /
    • 2011
  • To investigate the effects of pipe materials on biofilm accumulation and water quality, an annular reactor with the sample coupons of four pipe materials (steel, copper, stainless steel, and polyvinyl chloride) was operated under hydraulic conditions similar to a real plumbing system for 15 months. The bacterial concentrations were substantially increased in the steel and copper reactors with progression of corrosion, whereas those in stainless steel (STS) and polyvinyl chloride (PVC) reactors were affected mainly by water temperature. The heterotrophic plate count (HPC) of biofilms was about 100 times higher on steel pipe than other pipes throughout the experiment, with the STS pipe showing the lowest bacterial number at the end of the operation. Analysis of the 16S rDNA sequences of 176 cultivated isolates revealed that 66.5% was Proteobacteria and the others included unclassified bacteria, Actinobacteria, and Bacilli. Regardless of the pipe materials, Sphingomonas was the predominant species in all biofilms. PCR-DGGE analysis showed that steel pipe exhibited the highest bacterial diversity among the metallic pipes, and the DGGE profile of biofilm on PVC showed three additional bands not detected from the profiles of the metallic materials. Environmental scanning electron microscopy showed that corrosion level and biofilm accumulation were the least in the STS coupon. These results suggest that the STS pipe is the best material for plumbing systems in terms of the microbiological aspects of water quality.

The Development of the Korean Medical Insurance Economic Index(MIEI) (의료보험 수가수준의 조정을 위한 의료보험경제지수 (Medical Insurance Economic Index: MIEI)의 개발)

  • 김한중;손명세;박은철;최귀선;박웅섭;임종건;지영건
    • Health Policy and Management
    • /
    • 제9권1호
    • /
    • pp.156-177
    • /
    • 1999
  • The current method of rate adjustment for inflation is based on the evaluation of the financial performance of hospitals. The method has the disadvantage such as too complicated, expensive process as well as low reliability. This study, therefore, develops the 'Korean Medical Insurance Economic Index(MIEI)' as a new model for the rate adjustment with the use of the macro economic indices. In addition, we calculate the 1992∼1998 rate adjustment with the MIEI, and examines the validity of the MIEI by comparing with the conventional method. Medical costs are classified into nine categories : physician salaries, nurse·pharmacist·medical technician salaries, assistants & others salaries, material cost(by imports), material cost(by domestics), depreciation & rent paid(by imports), depreciation & rent paid(by domestics), power utilities, other administrative costs. Then the category weight which is the ratio of category in the total cost is calculated. Macro economic indices are selected for each cost category in order to reflect the concept of the each cost category and inflation during the year of 1992∼1998. Finally MIEI which integrate all category according to the category weight and selected macro indices is calculated. The mean of hospital MIEI which weighting by amount paid by insurers was cacluated. The result from the application of empirical data to the MIEI model is very similar to that of the current method. Furthermore, this method is very simple and also easy to get social consensus. This MIEI model can be replaced the current method based on the analysis of the financial performance for the adjustment of medical fees.