• Title/Summary/Keyword: 혼합 구조의 모델

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A Study on the Subject Specialization System Model of University Libraries in the 21st Century (21세기 대학도서관의 주제별 자료실 조직모형 연구)

  • Chung, Jae-young;Nam, Tae-Woo
    • Journal of the Korean Society for Library and Information Science
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    • v.38 no.1
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    • pp.173-197
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    • 2004
  • It is searched that 56 out of 185 university libraries(30.2%) has adopted 'subject specialization' organization. This 'subject specialization' emerged when university libraries began to care about their users and services for them more than other factors in planning and structuring their organization. The number of university libraries which try to adopt that organization has been continuously increasing. To settle 'subject specialization' in the university libraries under Korea's proper condition and to maximize its effect, each library should consider one's own conditions and step the reasonable procedure in adopting that system. Considering the similar condition which the university libraries in Korea face such as shortage of material support, 'Mixed Model of subject specialization" is reasonable, which means in whole structure of library function-oriented organization is adopted and in Reference Service, subject specialization is adopted. However, the ideal and final destination of Korea's university libraries is the adoption of 'Full subject specialized model": it can be reached when they are supported by sufficient human resources and good conditions.

MissCW:Multiuser Interactive System for Synchronous Collaborative Writing (MissCW:다중 사용자 동기적 공동 저작 시스템)

  • Seong, Mi-Yeong
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.7
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    • pp.1697-1706
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    • 1996
  • This paper presents the design and the implementation of a MissCW(Multi user Interactive System for Synchronous Collaborative Writing). The document model DMDA(Distributed Multimedia Document Architecture) of MissCW consists of the logical structure, presentation style object, and mark object. The windows. The collaborative editor of this system proposes a structure oriented editing mechanism to combine distrbuted objects into one document. The middleware SOM(Shared Object Manager) maintains shared objects consistently and helps application programs use objects efficiently. The infrastructure of this system is a hybrid structure of replicated and centralized architectures, that is to maintain shared objects consistently inside of SOM and to reduce the overhead of network traffic. The central part is a virtual node which corresponds to the Object Controller of SOMwith the SOT(Shared Objet Table).

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Unsteady Flamelet Modeling for Flame Structure and Soot Formation of Lanimar Non-premixed CH4/Air Flame (비정상 화염편 모델을 이용한 대기압 층류 비예혼합 CH4/Air 화염장의 매연입자 생성 특성 및 화염구조 해석)

  • Kim, Taehoon;Jeon, Sangtae;Kim, Yongmo
    • 한국연소학회:학술대회논문집
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    • 2012.11a
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    • pp.137-138
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    • 2012
  • The two-equation soot model based on the transient laminar flamelet model is implemented for soot formation of laminar non-premixed $CH_4/Air$ flame with detailed chemical reaction mechanism and complex thermodynamic properties. The soot model represents nucleation, growth and oxidation with gas-phase chemistry. This represented unsteady flamelet soot model has been tested and compared using well verified reference calculation result obtained solving the Full Transport Equations method.

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Fuzzy Model Identification Using A mGA Hybrid Scheme (mGA의 혼합된 구조를 사용한 퍼지모델 동정)

  • Lee, Yeun-Woo;Joo, Young-Hoon;Park, Jin-Bae
    • Proceedings of the KIEE Conference
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    • 1999.07b
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    • pp.507-509
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    • 1999
  • In this paper, we propose a new fuzzy model identification method that can yield a successful fuzzy rule base for fundamental approximations. The method in this paper uses a set of input-output data and is based on a hybrid messy genetic algorithm (mGA) with a fine-tuning scheme. The mGA processes variable-length strings, while standard GAs work with a fixed-length coding scheme. For successfully identifying a complex nonlinear system, we first use the mGA, which coarsely optimizes the structure and the parameters of the fuzzy inference system, and then the gradient descent method which tine tunes the identified fuzzy model. In order to demonstrate the superiority and efficiency of the proposed scheme, we finally show its application to a nonlinear approximation.

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Active Noise Transmission Control Through a Panel Structure Using a Frequency Domain Identification Method (주파수 영역 모델 방법을 이용한 평판 구조물의 능동 소음전달 제어)

  • Kim, Yeung-Shik;Kim, In-Soo;Moon, Chan-Young
    • Journal of the Korean Society for Precision Engineering
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    • v.18 no.9
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    • pp.71-81
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    • 2001
  • This paper analyzes the effectiveness of minimizing vibration and sound transmission on/through a thin rectangular plate by both feedback control and hybrid control which combines adaptive feedforward control with a feedback loop. An experimental system identification technique using the matrix-fractional curve-fitting of the frequency response data is introduced for complex shaped structures. This identification technique reduces the model order o the MIMO(Multi-Input Multi-Output) system which simplifies the practical implementation. The adaptive feedforward control uses a Multiple filtered-x LMS(Least Mean Square) algorithm and the feedback control uses a multivariable digital LQG(Linear Quadratic Gaussian) algorithm. Experimental results show that an effective reduction of sound transmission is achieved by the hybrid control scheme when both vibration and noise measurement signals are incorporated in the controller.

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공구파손의 파괴역학적 해석에 관한 기초적 연구

  • 이태세
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1992.04a
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    • pp.33-37
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    • 1992
  • 구조물과 기계부품에 부하를 주는 하중은 여러가지 종류가 있고, 이에 따르는 파괴의 형식도 여러가지가 있다. 그중에서도 연강압연용 로울러, 베어링 레일등은 집중 압축하중을 받는데 이들 부재의 파괴사고가 빈번히 일어나고 잇다. 압축에 의한 파괴 중 frectting, 피팅등과 같은 마모 현상은 두 재료의 표면이 서로 미끌어질때 일어나며, 이것이 공구나 기계부품의 성능과 수명을 저하시키는 주원인이 되며, 이러한 궁구나 기계 부품을 수리 또는 교환을 하기위한 인적, 경제적 손실은 막대하다. 본 연구에서는 금형등 공구의 마모편이 발생되는 마지막 과정인 크렉의 성장을 고찰하기 위하여 Sub-surface크랙 모델을 설정하여 2차원 유한요소 법으로 경계층 근방에 크랙이 존재하는 반무한 평면에 집중하중이 작용할때의 응력확대계수를 해설하였는데, 일반화된 해석법으로 혼합모드에서의 응력확대계수를 결정하였다.

분사액체와 운용조건이 공기충돌형 인젝터에 의해 형성되는 액적의 분무특성에 미치는 영향

  • Park, Seung-Gyu;Han, Jae-Seob;Kim, Yoo;Kim, Sun-Jin;Park, Jung-Bae
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 1999.04a
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    • pp.8-8
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    • 1999
  • 2-유체 인젝터의 분무연소에 대한 통찰 및 구조에 대한 이해와 연료-공기 혼합과 연소반응의 물리적 이해에 필요한 수치적 모델의 개발 및 검증을 위해서는 2유체 시스템에서 액체 및 기체 각각의 기본적 특성인 액적크기, 액적속도, 액적의 질량플럭스(flux), 가스상의 속도측정 등이 필요하다. 특히, 액체분무에서는 액적의 크기를 예측하는 것이 매우 중요한 과제이며, 액적의 크기에 영향을 주는 인자들로는 노즐의 형태, 분사액체의 물성치(점도, 표면장력, 밀도), 주위기체의 조건(온도, 압력, 응축과 증발현상), 분사압력 등이 있다. 그러나, 실제 분무액적의 크기는 분포를 가지므로 같은 SMD를 가지더라도 그 분포의 정도는 크게 다를 수 있어 결과적으로 분무액적의 크기를 평균값만으로 표현하는 것은 불충분할 뿐만 아니라 그 적용에도 한계를 가지게 된다. 따라서 분무액적의 평균크기와 함께 그 분포의 정도 등을 함께 나타내려는 시도가 많은 과학자들에 의하여 연구되었다.

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Relationship between Expandability, MacEwan Crystallite Thickness, and Fundamental Particle Thickness in Illite-Smectite Mixed Layers (일라이트-스멕타이트 혼합층광물의 팽창성과 MacEwan 결정자 및 기본입자두께에 관한 연구)

  • 강일모;문희수;김재곤;송윤구
    • Journal of the Mineralogical Society of Korea
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    • v.15 no.2
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    • pp.95-103
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    • 2002
  • The object of this study was to interpret the ralationship between expandability (% $S_{XRD}$), MacEwan crystallite thickness ( $N_{CSD}$), and mean fundamental particle thickness ( $N_{F}$ ) in illite-semctite mixed layer (I-S), quantitatively. This interpretation was extracted from comparison of two structural models (MacEwan crystallite model and fundamental particle model) of I-S mixed layers. In I-S structure, % $S_{XRD}$, $N_{CSD}$, and $N_{F}$ are not independent parameters but are related to each others by particular geometric relations. % $S_{XRD}$ is dependent on $N_{CSD}$ by short-stack effect, whereas, % $S_{XRD}$ and $N_{F}$ have relation to smectite interlayer number (Ns)=( $N_{F-}$1)/(100%/% $S_{XRD-}$ $N_{F}$ . Therefore, % $S_{XRD}$ and $N_{F}$ should satisfy a specific physical condition, 1< $N_{F}$ <100%/% $S_{XRD}$, because $N_{s}$ is positive. Based on this condition, this study suggested % $S_{XRD}$ vs $N_{F}$ diagram which can be used to interpret % $S_{XRD}$, $N_{F}$ , $N_{S}$ , and ordering, quantitatively. The diagram was examined by XRD data for I-S samples from Ceumseongsan volcanic complex, Korea. I-S samples showed that $N_{F}$ departs from the physical upper-limit ( $N_{F}$ =100%/% $S_{XRD}$) with decrease in % $S_{XRD}$. This phenomenon may happen due to decrease of stacking-capability of fundamental particles with their thickening.g.s with their thickening.g.

Vehicle Interior Noise Analysis Using Frequency Response Function Based Substructural Method (주파수응답함수의 부분구조합성 법을 이용한 차 실내소음 예측)

  • 허덕재;박태원
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.4
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    • pp.5-12
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    • 2001
  • This paper presents the simulation methodology of the interior noise of vehicle using the frequency response function based hybrid modeling of the system which consists of multi-subsystem models obtained by the test or analysis. The complex systems such as a trimmed body of high modal density and a powertrain were modeled by using experimental data, and a sub-frame of a vehicle of low modal density was modeled by finite element data. Modeling of the whole system was executed and validated in the two stages. The first stave is combining the trimmed body and the sub-frame, and the second stage is attaching the powertrain, which is a exciting source, to the combined model of the first stage. The input force to the system was modeled as an equivalent force in the virtual space, which was obtained from impedance method using the FRFs of the powertrain and the responses. The interior noise predicted by the proposed method was very close to the direct measurement, which showed feasibility of the proposed modeling procedure. Since the methodology is easily applied to both the transfer path analysis of structure-borne noise and the analysis of noise contribution of a sub-system, it is expected to be a strong tool for design change of a vehicle in the earlier stare.

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On Numerical Modeling of Kerosene/Liquid Oxygen Coaxial Swirl Injectors (케로신/액체산소 동축 와류형 분사기에 대한 수치해석 모델 고찰)

  • Kim, Seong-Ku;Choi, Hwan-Seok
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2010.11a
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    • pp.729-732
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    • 2010
  • The present study has been motivated by the development of a reliable numerical methodology for simulation of kerosene/LOx coaxial swirl injectors. To deal with thermodynamic non-ideality and anomalies of transport properties pronounced at supercritical pressures, a set of subroutine libraries has been constructed based on the cubic equations of state, and applied to an existing flamelet analysis code. For computational efficiency, two-dimensional axisymmetric RANS formulation with swirl was adopted and validated successfully against an isothermal coaxial swirling jet. For the actual problem with high pressure combustion, however, numerical results show that the RANS models yield excessive production of turbulence probably due to high density gradient magnitude in the vicinity of mixing layer of swirling film flow, and imply strongly further improvement of the turbulence models.

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