• Title/Summary/Keyword: strong discontinuity

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Effects of Fracture Tensor Component and First Invariant on Block Hydraulic Characteristics of the 2-D Discrete Fracture Network Systems (절리텐서의 성분 및 일차불변량이 2-D DFN 시스템의 블록수리전도 특성에 미치는 영향)

  • Um, Jeong-Gi
    • Economic and Environmental Geology
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    • v.52 no.1
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    • pp.81-90
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    • 2019
  • In this study, the effects of fracture tensor component and first invariant on block hydraulic behaviors are evaluated in the 2-D DFN(discrete fracture network) systems. A series of regression analysis is performed between connected fracture tensor components and block hydraulic conductivities estimated at every $30^{\circ}$ hydraulic gradient directions for a total of 36 DFN systems having various joint density and size distribution. The directional block hydraulic conductivity seems to have strong relation with the fracture tensor component estimated in direction perpendicular to it. It is found that an equivalent continuum approach could be acceptable for the 2-D DFN systems under condition that the first invariant of fracture tensor is more than 2.0~2.5. The first invariant of fracture tensor seems highly correlated with average block hydraulic conductivity and can be used to evaluate hydraulic characteristics of the 2-D DFN systems. Also, a possibility of upscaling using the first invariant of fracture tensor for the DFN system is addressed through this study.

Multi-material topology optimization for crack problems based on eXtended isogeometric analysis

  • Banh, Thanh T.;Lee, Jaehong;Kang, Joowon;Lee, Dongkyu
    • Steel and Composite Structures
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    • v.37 no.6
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    • pp.663-678
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    • 2020
  • This paper proposes a novel topology optimization method generating multiple materials for external linear plane crack structures based on the combination of IsoGeometric Analysis (IGA) and eXtended Finite Element Method (X-FEM). A so-called eXtended IsoGeometric Analysis (X-IGA) is derived for a mechanical description of a strong discontinuity state's continuous boundaries through the inherited special properties of X-FEM. In X-IGA, control points and patches play the same role with nodes and sub-domains in the finite element method. While being similar to X-FEM, enrichment functions are added to finite element approximation without any mesh generation. The geometry of structures based on basic functions of Non-Uniform Rational B-Splines (NURBS) provides accurate and reliable results. Moreover, the basis function to define the geometry becomes a systematic p-refinement to control the field approximation order without altering the geometry or its parameterization. The accuracy of analytical solutions of X-IGA for the crack problem, which is superior to a conventional X-FEM, guarantees the reliability of the optimal multi-material retrofitting against external cracks through using topology optimization. Topology optimization is applied to the minimal compliance design of two-dimensional plane linear cracked structures retrofitted by multiple distinct materials to prevent the propagation of the present crack pattern. The alternating active-phase algorithm with optimality criteria-based algorithms is employed to update design variables of element densities. Numerical results under different lengths, positions, and angles of given cracks verify the proposed method's efficiency and feasibility in using X-IGA compared to a conventional X-FEM.

A Qualitative Study on the Experience of Social Participation after Retirement of Baby Boomers through Social Contribution Jobs (사회공헌 일자리를 통한 베이비붐 세대의 퇴직 후 사회참여 경험에 관한 질적 연구)

  • Kim, Eun-Kyung
    • The Journal of the Korea Contents Association
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    • v.22 no.9
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    • pp.205-216
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    • 2022
  • This study investigated the experiences of baby boomers' social participation through social contribution jobs after retirement, using content analysis. The baby boomers who participated in social contribution jobs after retirement showed a strong desire to work, and were provided with rewarding and self-development, which resulted in family members viewing job participation positively. In addition, through self-help groups and communities, they shared information for the program and formed a social relationship. However, they expressed dissatisfaction with the instability and discontinuity of the job with low salary, with job interview repeated every year. As for the future direction, it is necessary that jobs utilize the skills and expertise of the baby boomers, the bridging jobs as an income guarantee after retirement, and the promotion of industries with marketability and publicness through institutional and regulatory reform. It is emphasized that the human resources of the retired baby boomers should be actively utilized with the governmental support.

Hydrogeological characteristics of a seepage area of white leachate (백색침출수 용출지역의 수리지질학적 고찰)

  • Kim, Man-Il;Park, Young-Gyu;Kim, Eul-Young;Kim, Yang-Bin;Yong, Hwan-Ho;Ji, Won-Hyun
    • The Journal of Engineering Geology
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    • v.20 no.4
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    • pp.381-390
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    • 2010
  • This study assessed the hydrogeological characteristics of a seepage area of white leachate. The geological characteristics of the leachate were determined by a surface survey, and an electrical resistivity survey and borehole image processing system (BIPS) were applied to estimate the distribution of discontinuities, to assess the geological structure of the seepage areas. Fluctuations in groundwater level within boreholes were measured during periods of precipitation in the dry and wet seasons. The results show that electrical resistivity is lower in the seepage section than in non-seepage sections. The distribution of fracture zones and limestone cavities was inferred from the logging data and BIPS data. Variations in groundwater level and groundwater recharge, related to rainfall events, show the direct effect of rainfall events during the rainy season. We obtained a strong relationship between seepage amount and rainfall (correlation coefficients of 0.83-0.97).

User-centered information service and a n.0, pplication of sense-making theory (이용자 중심 정보서비스와 Sense-making 이론의 적용)

  • ;Noh, Jin-Goo
    • Journal of Korean Library and Information Science Society
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    • v.28
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    • pp.447-475
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    • 1998
  • We are seeing a shift of the focus of information service from system-centered(data-centered or intermediary-centered) a n.0, pproach to user-centered a n.0, pproach. Sense-making theory is one of the user- centered a n.0, pproaches. This study focused on user-centered information service paradigm concepts of Dervin's sense-making theory and interpreting sense-making theory in the practical context of library services. The sense-making theory is basically a cognitive a n.0, pproach to information-seeking, in that it recognizes information as something that involves internal cognitive processes. The user of information becomes the focus in this sense-making model. The sense-making theory sees information as subjective, situational, and cognitive. It focuses on understanding information within specific contexts and on understanding how information needs develop and how they are satisfied. It regards the user not as a passive receive of external information but as the center in a active, ongoing process of change. It related to the information needs of users. Dervin's method for studying information needs employs the 'situation-gap-use' metaphor. All information needs stem from a discontinuity or 'gap! in one's knowledge. Dervin believes that information needs can be addressed by understanding the process that each individual goes through in experiencing a gap, in trying to resolve it, and in gaining something (especially new knowledge) from the experience. Sense-making is a process; 'sense' is the product of this process. Sense includes 'knowledge'. However, it includes a host of other subjective factors that reflect an individual's interpretations of a situation including intuitions, opinions, hunches, effective responses, evaluations, questions, etc. For several reasons, however, difficulties are encountered if one attempts a more substantial assessment of the theory. First, it has not yet crystallized into a well-defined theory. Secondly, though the theory has aroused general interest, e.g. within LIS, detailed discussion of its strong and weak points is still lacking. A third source of difficulty is that the basic assumptions of the theory have been explicated metaphorically. If sense-making theory is to be really useful, it needs to be interpreted for library settings. But we have found no attempt to construct an information service based on the theory. Because the research tradition is still relatively young, there are many unanswered questions connected, e.g. with the design of information systems. In any case, e.g. intermediary access systems would be more efficient and effective it their planning could be founded on the user-centered a n.0, pproach.

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Properties of Disconitinuity for the Seoul Granite in the Northeastern Part of Seoul City (서울시 북동부의 서울화강암에 대한 불연속면의 특성)

  • 정상원;정상용
    • The Journal of Engineering Geology
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    • v.12 no.2
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    • pp.167-178
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    • 2002
  • Properties of discontinuity for Seoul Granite in northeastern part of Seoul City were analyzed by dividing structural domains into Surak and Bulam Mtn. areas. Important parameters measured among several engineering properties of a rock during tunnel excavation and road construction are as follows: 1) Orientation of joint, 2) joint spacing, 3) joint density, and 4) uniaxial compressive strength. Orientation, spacing, and density of joints can be directly measured during field investigation using scanline survey, circle-inventory method, and window survey. Uniaxial compressive strength of the rock was calculated by a simple correlation equation although it is originally necessary to prepare core samples in measuring it. Major orientations of joints measured from both areas are 3 sets of joints with different orientations. In other words, they are 2 sets of orthogonal joint and 1 set of sheet joint that is dipping at low angle, and have very similar orientations in both areas. Joint densities in both areas range from 0.039 and 0.066/cm, and average joint length are between 1.30 and 4.52m. Average joint spacing also has values from 10.3cm up to 59.6cm, and shows significant difference along specific orientation of scanlines measured. Values of uniaxial compressive strength calculated on the basis of Schmidt hammer rebound values range from 217 to 335 MPa, which indicates very strong rock type by classification of wall strength.

A Study of Deconstruction in Clothing -Comparison of Clothing with Architecture- (복식에 나타난 해체주의 양식연구 -건축과 복식의 비교-)

  • 전혜정
    • Journal of the Korean Society of Costume
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    • v.32
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    • pp.293-312
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    • 1997
  • Deconstructionism is a philosophical stream in the latter half of 20'th century which goes against western metaphysics and tries to deconstruct the dualism e.g. eastern/west-ern man/woman. Its main concepts are 'indi-vidual' 'other' 'difference' 'restoration of the repressed' 'decentralization' 'Today it shows strong influences in literature art, and other social fields. This study investigated inner meanings and exterior forms represented in clothing on the base of Jacques Derrida's theory in order to re-search modes of deconstruction in is. And it compared clothing with architecture among other genres of art in order to discover similarities between through and modes of art in a certain period. For illuminating concept of deconstruction I referred to the literatures of preceding studies and for deconstruction's characteristics in both clothing and architec-ture I referred work's collection book $\ulcorner$collec-tions$\lrcorner$ and other related books dealing from 1960's to this point. As a rsult there are four modes of decons-truction in both clothing and architecture as follows; 1) Differenance which is a concept of the dif-ference in time and space as being trace. 2) In termeaning of meanings which is not present in reality but re-interpreted a new in the future. 3) Interxtuality in which a texte is not alone but with others 4) Dis.De phenomenon in which distortion and fragmentation forms occur as the result of the denial of perfection and reson. There are characteristics of modes of de-construction in clothing as follows; 1) Differance; R.Gigli, P. Rabanne. G.Bersace, V.Westwood are representatives of the cloth-ing which is combined with the past the pres-ent and the future or is re-viewed as the clothing of the past in the present point of view. J. Watanabe R. Dawakubo I miyake are representatives of the clothing which is out-date but re-viewed in the sense of recollec-tion and re-usage. 2) Intermeaning of meanings: R. kawakubo I, Miyake Y,Yamamoto are representatives of the clothing which is incomplete but re-interpreted in the future and appears to be new-fashioned according to ways of bnding wearing throwing on and tying J.C. Castel-bajac K.Hamnett S.Sprouse are representa-tives of the clothing which is made up of ab -stract forms scribbling or symbolic letters which appears to be different according to view-point of observers. 3) Intertextuality ;J.P.Gaultier K.Hamnett, Comme des Gar ons are representatives of intertextuality of gender which avoids the 여-ality of man/woman J.P Gaultier G,Versace J. galliano are representatives of the intertex-tuality of time place and occasion which mixes temporality extensity and purposiveness. J.P Gaultier G,Versace are representatives of the intertextuality of coordination which combines items different in image purpose and use. P.Rabanne A,Courr ges R,Gernreic I,Miyake are representatives of the intertextuality of mat-ter which uses heterogeneous matter different from cloth. 4) Dis.De-phenomenon: R, Kawakubo I.Mi-yake J.P.Gaultier are representatives of the de-composition which discloses distortion and exag-geration of form through destructing the estab-lished way of construction J.Galliano R.Kawa-kubo Devota Y Lomba arte representatives of the decentring which restores the repressed and the alienated on the one hane and shows front-centrality on the other. Comme des Gar ones is representative of the discontinuity because of which right and left up and down are not in har-mony with one another. J,Galliano J.P,Gaultier T,Mugler are representatives of the disruption by way of which one makes one's body exposed through intentional slashes or holes. As a consequence deconstructionism enabled us to investigate similarities between through of deconstruction and modes of art interms of diffrance Intermeaning of meanings intertextuality and Dis De-phenomenon. And we found that deconstruction was a phase of development in that it as a all-comprising and multiple concept tries to pursue the new through deconstruction.

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