• Title/Summary/Keyword: 미시구조

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A Study on the Microstructure of Terminological Dictionaries (전문용어사전의 미시구조에 관한 연구)

  • 김성진;정동열
    • Journal of the Korean Society for Library and Information Science
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    • v.35 no.1
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    • pp.143-162
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    • 2001
  • As technical intellectual work now has become prolific and various, rapid evolution of technical terms needs to collect and manage them systematically and efficiently. The purpose of this study is to suggest the microstructure for systematic definitions of definiendum in terminological dictionaries. This study reveals specific properties or differences of terminography on the basis of terminology and lexicography, analyzes problems of microstructure in a current terminological dictionary, and, based upon the theoretical and practical analysis, attempts to derive structural and methodical suggestions for microstructure of terminological dictionaries.

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Extending the MARTIF and TEI for Korean Lexical Entities (한국어사전 인코딩체계의 확장에 관한 연구: MARTIF와 TEI를 중심으로)

  • 백지원;최석두
    • Journal of the Korean Society for information Management
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    • v.18 no.2
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    • pp.295-322
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    • 2001
  • The purpose of this study is to present a scheme to encode all possible lexical entities in dictionaries, glossaries, encyclopedias, and thesaurus, etc. First, it discussed the nature and structure of dictionaries. Second, two current major terminological data encoding schemes, MARTIF and TEI were analyzed in terms of their flexibility for extension to encompass all lexical entities. Third, an integrated microstructure of dictionaries was presented and compared with the MARTIF and TEI for print dictionaries. Then, the need and 17 suggestions for extended MARTIF and TEI formats were addressed with specific cases, which combined with the suggestions from two studies concerning MARTIF and TEI DTD modification for the markup of Korean dictionary entries.

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분말소결 알루미늄 합금의 반복하중에 의한 미시균열 성장연구

  • ;;Klaus Detert
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1991.11a
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    • pp.21-31
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    • 1991
  • 대부분의 구조물은 정하중뿐아니라 동하중을 받고있으며, 반복되는 동하중에 의해 구조물은 피로를 받게되고 가장 취약한 부위에 작은 미시균열이 발생된다. 미시균열이 성장, 확산되어 기술적으로 인지되는 길이가 0.5 mm 이상이 될때 이를 거시균열이라 하는데, 거시균열의 균열성장은 파괴역학적 해석 방법의 도입으로 많은 공학적 재료들이 광범위하게 연구되었으며, 거시균열의 확산과 연관되어지는 균열닫힘과 미시구조의 관계가 연구되었다. 최근에는 거시균열의 해석과 같이 응력강도가 미시균열에서의 확산거동에 미치는 영향을 설명하는데 많은 관심을 가지게 되었다.(중략)

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A Bootstrap Lagrangian Multiplier Test for Market Microstructure Noise in Financial Assets (금융자산의 시장 미시구조 잡음에 대한 부트스트래핑 라그랑지 승수 검정)

  • Kim, Hyo Jin;Shin, Dong Wan;Park, Jonghun;Lee, Sang-Goo
    • The Korean Journal of Applied Statistics
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    • v.28 no.2
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    • pp.189-200
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    • 2015
  • Stationary bootstrapping is applied to a Lagrangian multiplier (LM) test to test market microstructure noise (MMN) in financial asset prices. A Monte-Carlo experiment shows that the bootstrapping method improves the size of the original LM test which has some size distortion for conditional heteroscedastic models. The proposed test is illustrated for real data sets like KOSPI index and Won-Dollar exchange rate.

Microstructure Properties of Cement Extruding Solid using Waste Concrete Powder (폐콘크리트 미분말을 사용한 압출경화체의 미시구조 특성)

  • Yu, Jae-Seong;Kim, Jin-Man;Sun, Jeong-Soo;Choi, Hong-Bum
    • Proceedings of the Korean Institute of Building Construction Conference
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    • 2016.05a
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    • pp.55-56
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    • 2016
  • In the recent concrete industry, when producing recycled aggregates, waste concrete powder is by-produced in large quantities; however, since it is not used properly but buried or discarded. This study is to apply the waste concrete powder to a cement extruding panel as filler. Flexural strength and microstructure characteristics of panel is tested in order to improve the economics of the extruding panel. As a results of this study, it was found that extruding panel replacing silica(No.8) as the waste concrete powder totally showed little difference in the strength and satisfied the target flexural strength of 14MPa, comparing with controlled panel. In addition, we can understand that rich Portlandite and Calcite contributed to develop the strength in all curing conditions from XRD pattern.

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Market Microstructure Noise and Optimal Sampling Frequencies for the Realized Variances of Stock Prices of Four Leading Korean Companies (한국주요상장사 주가 실현변동성 추정시 시장미시구조 잡음과 최적 추출 빈도수)

  • Oh, Rosy;Shin, Dong-Wan
    • The Korean Journal of Applied Statistics
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    • v.25 no.1
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    • pp.15-27
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    • 2012
  • We have studied the realized variance(RV) of intra-day returns and market microstructure noise based on high-frequency stock transaction data for the four largest companies in terms of market capitalization in the KOSPI. First, non-negligible biases are observed for the RV and for the bias-corrected realized variance($RV_{AC_1}$) which is constructed by adjusting RV for the first order autocorrelation in intra-day returns. Bias is more obvious for the RV and the $RV_{AC_1}$ when intra-day returns are sampled more frequently than every 2 minutes. Transaction Time Sampling(TTS) is shown to be better than Calendar Time Sampling(CTS) in terms of biases of the RV and the $RV_{AC_1}$ for the 4 companies. The analysis reveals that market microstructure noise is temporally dependent. Second, by using the Noise-to-Signal Ratio(NSR), we estimate sampling frequencies that are optimal in terms of the Mean Square Errors(MSE) of the RV and the $RV_{AC_1}$. The optimal sampling frequencies are around 200 for RV and is around 5000 for the $RV_{AC_1}$ for all the four stock prices. For the 6 hour transaction period of the Korean stock trading, these correspond to about 2 minutes and 6 seconds.

low Velocity Impact Behavior Analysis of 3D Woven Composite Plate Considering its Micro-structure (미시구조를 고려한 3차원 직교직물 복합재료 평판의 저속충격 거동해석)

  • Ji, Kuk-Hyun;Kim, Seung-Jo
    • Composites Research
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    • v.18 no.4
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    • pp.44-51
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    • 2005
  • In this paper, we developed the direct numerical simulation(DNS) model considering the geometry of yams which consist of 3D orthogonal woven composite materials, and using this model, the dynamic behavior of under transverse low-velocity impact has been studied. To build up the micromechanical model considering tow spacing and waviness, an accurate unit structure is presented and used in building structural plate model based on DNS. For comparison, DNS results are compared with those of the micromechanical approach which is based on the global equivalent material properties obtained by DNS static numerical tests. The effects with yarn geometrical irregularities which are difficult to consider in a macroscopic approach are also investigated by the DNS model. Finally, the multiscale model based on the DNS concepts is developed to enhance efficiency of analysis with real sized numerical specimen and macro/micro characteristics are presented.

Laboratory Tests and Numerical Simulations for Prediction of Stress-Stain Behavior Using Construction Materials for Embankment (제방축조재료의 응력-변형거동 예측을 위한 실내시험 및 수치해석)

  • Jeong, Sang-Guk;Koo, Ja-Kap
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.14 no.6
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    • pp.215-219
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    • 2010
  • The evaluation of the mechanical properties and behavior is very important for the design of embankment using granular materials. In this research, the lab. tests with Nak-dong river sand were conducted to find out mechanical properties related to stress-strain behavior. Also, numerical simulations which can express the behavior of granular material were conducted by distinct element method. Distinct element method can play a import role to predict stress-strain behavior for different confining stress and loading condition if micro-parameters can be estimated in specific condition.