• Title/Summary/Keyword: description elements

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Parameterising a Microplankton Model

  • Lee, Jae-Young;Tett, Paul;Kim, Kyung-Ryeul
    • Journal of the korean society of oceanography
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    • v.38 no.4
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    • pp.185-210
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    • 2003
  • This paper describes and assesses the parameterisation of MP, the microplankton compartment of the carbon­nitrogen microplankton­detritus model. The compartment is 'the microbial loop in a box' and includes pelagic bacteria and protozoa as well as phytoplankton. The paper presents equations and parameter values for the autotroph and microheterotroph components of the microplankton. Equations and parameter values for the microplankton as a whole are derived on the assumption of a constant 'heterotroph fraction'. The autotroph equations of MP allow variation in the ratios of nutrient elements to carbon, and are largely those of the 'cell­quota, threshold­limitation' algal growth model, which can deal with potential control of growth by several nutrients and light. The heterotroph equations, in contrast, assume a constant elemental composition. Nitrogen is used as the limiting nutrient in most of the model description, and is special in that MP links chlorophyll concentration to the autotroph nitrogen quota.

On FEM modeling of piezoelectric actuators and sensors for thin-walled structures

  • Marinkovic, Dragan;Marinkovic, Zoran
    • Smart Structures and Systems
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    • v.9 no.5
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    • pp.411-426
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    • 2012
  • Thin-walled adaptive structures render a large and important group of adaptive structures. Typical material system used for them is a composite laminate that includes piezoelectric material based sensors and actuators. The piezoelectric active elements are in the form of thin patches bonded onto or embedded into the structure. Among different types of patches, the paper considers those polarized in the thickness direction. The finite element method (FEM) imposed itself as an essential technical support for the needs of structural design. This paper gives a brief description of a developed shell type finite element for active/adaptive thin-walled structures and the element is, furthermore, used as a tool to consider the aspect of mesh distortion over the surface of actuators and sensors. The aspect is of significance for simulation of behavior of adaptive structures and implementation of control algorithms.

A Study on the Behavior of Cylindrical Shell Structure Subjected to Axial Compression (축압축력을 받는 원통형 축대칭 쉘구조의 거동에 관한 연구)

  • 조현영;정진환;황상필
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1997.10a
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    • pp.249-253
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    • 1997
  • A numerical method for evaluating the equilibrium path of cylindrical shell subject to axial load and eccentrically axial load is presented. The effects of both material and geometric nonlinearities were also considered in the analysis. The nonlinear formulation was based on the total Lagrangian description and nonlinear equtions were solved by the Newton-Raphson method with load increment procedures. Degenerate shell elements with layered approach were employed for the analysis. The elasto-plastic deformation can be found in several examples and a large eccentricity of the axial load reduces the stress level at the time of the local buckling of the pipe considerably.

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A Study on the Breaking Phenomena Varying with Notch Shape of Fuse-Element (휴즈 엘리먼트 노치 형태에 따른 차단특성에 관한 연구)

  • Lee, B.S.;Lee, S.H.;Lee, J.C.;Bark, G.B.;Han, S.O.;Kim, J.S.
    • Proceedings of the KIEE Conference
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    • 1994.07b
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    • pp.1382-1384
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    • 1994
  • Description is given of the effect of fuse-element notch shape on interruption parameters. The notch of fuse-elements have all the same area. Tests were carried out at direct current and carried out the effect of the fuse element construction on the process of interrupting short circuit and overload current. The arcing phenomenon in a low voltage fuse operation in case of high current value of short circuit is analyzed.

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A Faceted Data Model for Bibliographic Integration Between MARC and FRBR

  • Lee, Seungmin
    • Journal of Information Science Theory and Practice
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    • v.1 no.1
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    • pp.69-82
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    • 2013
  • Although MAchine Readable Cataloging (MARC) and Functional Requirements for Bibliographic Records (FRBR) are currently the most broadly used bibliographic structures for generating bibliographic data in the library community, each has its own weaknesses in describing information resources in diverse media. If the MARC format could be implemented in a structure that reflects the multi-layered characteristics of FRBR, its use could address current problems and limitations in resource description. The purpose of this research is to propose an alternative approach that can integrate the heterogeneous bibliographic structures of MARC and FRBR through the applications of facet and facet analysis. The proposed faceted data model is expected to function as a conceptual structure that can mediate between MARC data elements and FRBR attributes in order to utilize these structures in a more reliable and comprehensive way.

Some Comments on and an Extension to Activity Structures for Intelligent Systems

  • Hall, Lawrence O.
    • Journal of the Korean Institute of Intelligent Systems
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    • v.3 no.1
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    • pp.23-28
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    • 1993
  • Activity structures are a set of functional structures which may be used to provide a uniform framework for the description of information processing systems. The interaction of some aspects of activity structures is discussed. Intelligent systems, a subset of information handling systems, are the primary emphasis of this work. An extension to the functional structures of the activity structures is proposed. The proposed structure is a met a-structure which affects most elements of an intelligent system. The structure is concerned with describing the way uncertainty in an environment is handled by a system. An example is given which shows the importance of describing the uncertainty handling method(s) of an intelligent system.

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A Study on Development of Micro Controller for Converter using VHDL (VHDL을 이용한 전력변환용 마이크로 컨트롤러 개발에 관한 연구)

  • Seo, Young-Jo;Oh, Jeong-Eon;Yoon, Jea-Shik;Kim, Beung-Jin;Jeon, Hee-Jong
    • Proceedings of the KIEE Conference
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    • 2000.07b
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    • pp.1071-1073
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    • 2000
  • The use of HDL(Hardware Description Language) is now central to the ASIC(Application Specific Integrated Circuit). HDL-based ASIC can simplify the process of development and has a competition in market because it reduce the consuming time for the design of IC(Integrated circuit) in system level. Therefore, the development of power electronics system on chip (SOC), to design microcontroller and switching logic as one chip, is required extremely for the purpose of having reliability and low cost in power electronics which is based on switching elements. The major application of SOC is variable converter, active filter inverter for induction motor. UPS and power supply with a view to reducing electro-magnetic pollution.

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A Study on Implementation of Out-of-Step Detection Algorithm using VHDL (VHDL을 이용한 동기탈조 검출 알고리즘 구현에 관한 연구)

  • Kim, Chul-Hwan;Kwon, O-Sang
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.5
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    • pp.179-184
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    • 2006
  • In a power system, an out-of-step condition causes a variety of risk such as serious damage to system elements, tripping of loads and generators, mal-operation of relays, etc. Therefore, it is very important to detect the out-of- step condition and take a proper measure. This paper presents a study on implementation of out-of-step detection algorithm using VHDL(Very high speed Hardware Description Language). The structure of out-of-step detection algorithm is analyzed for development of out-of-step detection relay on the FPGA(Field Programmable Gate Array). The out-of-step algorithm is separated to 4 parts: DFT IP, complex power calculation IP, out-of-step detection IP, control unit. Each parts are developed and simulated by using VHDL.

Vortex excitation model. Part I. mathematical description and numerical implementation

  • Lipecki, T.;Flaga, A.
    • Wind and Structures
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    • v.16 no.5
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    • pp.457-476
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    • 2013
  • This paper presents theoretical background for a semi-empirical, mathematical model of critical vortex excitation of slender structures of compact cross-sections. The model can be applied to slender tower-like structures (chimneys, towers), and to slender elements of structures (masts, pylons, cables). Many empirical formulas describing across-wind load at vortex excitation depending on several flow parameters, Reynolds number range, structure geometry and lock-in phenomenon can be found in literature. The aim of this paper is to demonstrate mathematical background of the vortex excitation model for a theoretical case of the structure section. Extrapolation of the mathematical model for the application to real structures is also presented. Considerations are devoted to various cases of wind flow (steady and unsteady), ranges of Reynolds number and lateral vibrations of structures or their absence. Numerical implementation of the model with application to real structures is also proposed.

Reduced Rank Eigen-Space Beamforming for Adaptive Array Systems (적응형 배열 안테나를 위한 감소 차수 고유 공간 빔형성 알고리즘)

  • Hyeon, Seung-Heon;Choi, Seung-Won
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.4C
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    • pp.336-341
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    • 2008
  • In this paper, beamforming algorithm is proposed which can obtain diversity gain in beamforming system that deploy antenna elements with half-wavelength. The proposed algorithm provides beam-pattern using eigen-vectors that span received signal subspace. The criterion to decide optimal rank of eigen-space used for beamforming is also proposed. A beamforming system applied the proposed algorithm shows better performance with diversity gain as getting larger angle spread. This paper provides a description of proposed algorithm with analysis of the performance using various computer simulations.