• 제목/요약/키워드: Hierarchical Structures

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반말과 계층 구조 -정대현 교수의 반말 이론에 대한 비판적 검토- (Ban-mal and Hierarchical Structures : Professor Chung′s Theory Critically Examined)

  • 선우환
    • 인문언어
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    • 제5권
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    • pp.93-106
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    • 2003
  • Professor Daihyun Chung has recently presented an intriguing view of Ban-mal(non-honorific expressions) in Korean. He criticizes uses of Ban-mal, on the grounds that they presuppose the existence of hierarchical structures in human beings. Professor Chung also advocates ″a relational theory of Ban-mal″ according to which ascriptions of 'n-mal' should be relativized to the speaker-hearer relationship. He employs this view in showing that uses of Ban-mal indeed presuppose the existence of hierarchical structures in human beings I claim that Professor Chung has not shown the credibility of his relational theory of Ban-mal, and that this very view leads to an unintended and undesirable consequence. Moreover, 1 show that even if we assume that this view is true for the sake of an argument, he is not able to show that uses of Ban-mal indeed presuppose the existence of hierarchical structures. All he can show is rather that uses of 'Ban-mal'(a meta-linguistic expression) presuppose the existence of hierarchical structures. Finally, 1 conclude that what really presupposes the existence of hierarchical structures is the asymmetrical uses of Ban-mal and honorific expressions.

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박판 탄성구조물의 최적해석을 위한 계층적 모델에 관한 연구 (A Study of Hierarchical Models for the Optimal Analysis of Thin Elastic Structures)

  • 조진래
    • 대한기계학회논문집A
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    • 제21권6호
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    • pp.933-941
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    • 1997
  • In the analysis of thin elastic structures such as plate and shell-like structures, classical lower-order theories like Kirchhoff and Reissner-Mindin theories are insufficient to describe the behavior of such structures in the region where the state of stresses is complex. On the other hand, the fully three dimensional theory of linear elasticity can provide desired analysis accuracy, but requires expensive computational implementation compared to the classical theories. This paper is concerned with the development of hierarchical models for elastic structures which can be used for hierarchical modeling for the analysis of such structures. Derivation and limit model analysis (when the thickness of structures tends to zero) of hierarchical models are presented together with a introduction of modeling error estimation. Also, numerical results supporting theoretical results are given.

생체구조를 모방한 다층복합재료의 이방성 유효탄성계수 및 저속 충격 해석 (Analysis of Effective Anisotropic Elastic Constants and Low-Velocity Impact of Biomimetic Multilayer Structures)

  • 이종원;범현규
    • 한국정밀공학회지
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    • 제29권11호
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    • pp.1245-1255
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    • 2012
  • Effective elastic constants of biomimetic multilayer structures with hierarchical structures are evaluated based on the potential energy balance method. The effective anisotropic elastic constants are used in analyzing low-velocity impact of biomimetic multilayer structures consisting of mineral and protein. It is shown that displacements of biomimetic multilayer structures strongly depend on the volume fraction of mineral and hierarchical level. The effect of the volume fraction of mineral and hierarchical level on the contact force and stresses at the impact point are also discussed.

마이크로/나노 계층구조 형성법 및 응용 (Fabrication of micro/nanoscale hierarchical structures and its application)

  • 정훈의;곽노균;이승석;서갑양
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회A
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    • pp.426-428
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    • 2007
  • A simple method is presented for fabricating micro/nanoscale combined hierarchical structures using a two-step UV-assisted capillary molding technique. This lithographic method consists of two steps: (i) fabrication of partially cured polymer microstructures using a PDMS mold and (ii) subsequent nanofabrication using a high-resolution polyurethane acrylate (PUA) mold on top of the pre-formed microstructures. Using this technique, various micro/nano hierarchical structures were fabricated with minimum resolution down to 70 nm over a large area with very good reproducibility.

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2단계 모세관 리소그라피 기술을 이용한 마이크로/나노 병합구조 공정 기술 및 수학적 모델을 통한 표면 특성 분석 (Fabrication of polymer hierarchical structures by two-step temperature-directed capillary)

  • 서갑양;정훈의;이성훈;김재관
    • 한국정밀공학회:학술대회논문집
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    • 한국정밀공학회 2005년도 추계학술대회 논문집
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    • pp.272-274
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    • 2005
  • A simple method for fabricating micro/nanoscale hierarchical structures is presented using a two-step temperature-directed capillary molding technique. This lithographic method involves a sequential application of molding process in which a uniform polymer-coated surface is molded with a patterned mold by means of capillary force above the glass transition temperature of the polymer. Using this approach, multiscale hierarchical structures for biomimetic functional surfaces can be fabricated with precise control over geometrical parameters and the wettability of a solid surface can be designed in a controllable manner.

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피라미드 구조를 이용한 계층적 hausdorff distance 정합 (Hierarchical hausdorff distance matching using pyramid structures)

  • 권오규;심동규;박래홍
    • 전자공학회논문지S
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    • 제34S권12호
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    • pp.70-80
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    • 1997
  • This paper proposes a hierarchical Hausdorff distance (HD) matching algorithm baased on coarse-to-fine approach. It reduces the computational complexity greatly by using the pyramidal structures consisting of distance transform (DT) and edge pyramids. Also, inthe proposed hierarchical HD matching, a thresholding method is presented to find an optimal matching position with small error, in which the threshold values are determined by using the property between adjacent level of a DT map pyramid. By computer simulation, the performance of the conventional and proposed hierarchical HD matching algorithms is compared in therms of the matching position for binary images containing uniform noise.

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고온 임프린팅을 통한 알루미늄합금 표면의 마이크로/나노 구조 성형 기술 (Hot Imprinted Hierarchical Micro/Nano Structures on Aluminum Alloy Surfaces)

  • 문인용;이호원;오영석;김세종;김지훈;강성훈
    • 소성∙가공
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    • 제28권5호
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    • pp.239-246
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    • 2019
  • Various surface texturing techniques have been studied because of the effective applicability of micro or nano scale surface patterns. Particularly, the most promising types of patterns include the hierarchical patterns, which consists of micro/nano structures. Different processes such as MEMS, laser machining, micro cutting and micro grinding have been applied in the production of hierarchical patterns on various material surfaces. This study demonstrates the process of hot imprinting to induce the hierarchical patterns on the Al alloy surfaces. Wire electrical discharge machining (WEDM) process was used to imprint molds with micro scale sinusoidal pattern. In addition, the sinusoidal pattern with rough surface morphology was obtained as a result of the discharge craters. Consequently, the hierarchical patterns consisting of the sinusoidal pattern and the discharge craters were prepared on the imprinting mold surface. Hot imprinting process for the Al plates was conducted on the prepared mold, and the replication performance was analyzed. As a result, it was confirmed that the hierarchical patterns of the mold were effectively duplicated on the surface of Al plate.

A POSTERIORI ERROR ESTIMATOR FOR HIERARCHICAL MODELS FOR ELASTIC BODIES WITH THIN DOMAIN

  • Cho, Jin-Rae;J. Tinsley Oden
    • Journal of Theoretical and Applied Mechanics
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    • 제3권1호
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    • pp.16-33
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    • 2002
  • A concept of hierarchical modeling, the newest modeling technology. has been introduced early In 1990. This nu technology has a goat potential to advance the capabilities of current computational mechanics. A first step to Implement this concept is to construct hierarchical models, a family of mathematical models which are sequentially connected by a key parameter of the problem under consideration and have different levels in modeling accuracy, and to investigate characteristics In their numerical simulation aspects. Among representative model problems to explore this concept are elastic structures such as beam-, arch-. plate- and shell-like structures because the mechanical behavior through the thickness can be approximated with sequential accuracy by varying the order of thickness polynomials in the displacement or stress fields. But, in the numerical analysis of hierarchical models, two kinds of errors prevail: the modeling error and the numerical approximation errors. To ensure numerical simulation quality, an accurate estimation of these two errors Is definitely essential. Here, a local a posteriori error estimator for elastic structures with thin domain such as plate- and shell-like structures Is derived using element residuals and flux balancing technique. This method guarantees upper bounds for the global error, and also provides accurate local error Indicators for two types of errors, in the energy norm. Comparing to the classical error estimators using flux averaging technique, this shows considerably reliable and accurate effectivity indices. To illustrate the theoretical results and to verify the validity of the proposed error estimator, representative numerical examples are provided.

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A posteriori error estimator for hierarchical models for elastic bodies with thin domain

  • Cho, Jin-Rae
    • Structural Engineering and Mechanics
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    • 제8권5호
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    • pp.513-529
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    • 1999
  • A concept of hierarchical modeling, the newest modeling technology, has been introduced in early 1990's. This new technology has a great potential to advance the capabilities of current computational mechanics. A first step to implement this concept is to construct hierarchical models, a family of mathematical models sequentially connected by a key parameter of the problem under consideration and have different levels in modeling accuracy, and to investigate characteristics in their numerical simulation aspects. Among representative model problems to explore this concept are elastic structures such as beam-, arch-, plate- and shell-like structures because the mechanical behavior through the thickness can be approximated with sequential accuracy by varying the order of thickness polynomials in the displacement or stress fields. But, in the numerical, analysis of hierarchical models, two kinds of errors prevail, the modeling error and the numerical approximation error. To ensure numerical simulation quality, an accurate estimation of these two errors is definitely essential. Here, a local a posteriori error estimator for elastic structures with thin domain such as plate- and shell-like structures is derived using the element residuals and the flux balancing technique. This method guarantees upper bounds for the global error, and also provides accurate local error indicators for two types of errors, in the energy norm. Compared to the classical error estimators using the flux averaging technique, this shows considerably reliable and accurate effectivity indices. To illustrate the theoretical results and to verify the validity of the proposed error estimator, representative numerical examples are provided.

Hierarchical Structure in Semantic Networks of Japanese Word Associations

  • Miyake, Maki;Joyce, Terry;Jung, Jae-Young;Akama, Hiroyuki
    • 한국언어정보학회:학술대회논문집
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    • 한국언어정보학회 2007년도 정기학술대회
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    • pp.321-329
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    • 2007
  • This paper reports on the application of network analysis approaches to investigate the characteristics of graph representations of Japanese word associations. Two semantic networks are constructed from two separate Japanese word association databases. The basic statistical features of the networks indicate that they have scale-free and small-world properties and that they exhibit hierarchical organization. A graph clustering method is also applied to the networks with the objective of generating hierarchical structures within the semantic networks. The method is shown to be an efficient tool for analyzing large-scale structures within corpora. As a utilization of the network clustering results, we briefly introduce two web-based applications: the first is a search system that highlights various possible relations between words according to association type, while the second is to present the hierarchical architecture of a semantic network. The systems realize dynamic representations of network structures based on the relationships between words and concepts.

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