• Title/Summary/Keyword: coefficient ideal

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Combustion Characteristics of Hydrogen by the Thermodynamic Properties Analysis

  • Han, Sung Bin
    • Journal of Energy Engineering
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    • v.24 no.2
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    • pp.84-90
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    • 2015
  • Hydrogen has some remarkably high values of the key properties for transport processes, such as kinematic viscosity, thermal conductivity and diffusion coefficient. Hydrogen, as an energy medium, has some distinct benefits for its high efficiency and convenience in storage, transportation and conversion. Hydrogen has much wider limits of flammability in air than methane, propane or gasoline and the minimum ignition energy is about an order of magnitude lower than for other combustibles. Statistical thermodynamics provides the relationships that we need in order to bridge this gap between the macro and the micro. Our most important application will involve the calculation of the thermodynamic properties of the ideal gas.

Thangka Image Inpainting Algorithm Based on Wavelet Transform and Structural Constraints

  • Yao, Fan
    • Journal of Information Processing Systems
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    • v.16 no.5
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    • pp.1129-1144
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    • 2020
  • The thangka image inpainting method based on wavelet transform is not ideal for contour curves when the high frequency information is repaired. In order to solve the problem, a new image inpainting algorithm is proposed based on edge structural constraints and wavelet transform coefficients. Firstly, a damaged thangka image is decomposed into low frequency subgraphs and high frequency subgraphs with different resolutions using wavelet transform. Then, the improved fast marching method is used to repair the low frequency subgraphs which represent structural information of the image. At the same time, for the high frequency subgraphs which represent textural information of the image, the extracted and repaired edge contour information is used to constrain structure inpainting in the proposed algorithm. Finally, the texture part is repaired using texture synthesis based on the wavelet coefficient characteristic of each subgraph. In this paper, the improved method is compared with the existing three methods. It is found that the improved method is superior to them in inpainting accuracy, especially in the case of contour curve. The experimental results show that the hierarchical method combined with structural constraints has a good effect on the edge damage of thangka images.

The ECBL approach for interactive buckling of thin-walled steel members

  • Dubina, Dan
    • Steel and Composite Structures
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    • v.1 no.1
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    • pp.75-96
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    • 2001
  • Actual buckling curves are always characterised by the erosion of ideal buckling curves. In case of compact sections this erosion is due to the imperfections, while for thin-walled members, a supplementary erosion is induced by the phenomenon of coupled instabilities. The ECBL approach- Erosion of Critical Bifurcation Load - represents a practical and convenient tool to characterise the instability behaviour of thin-walled members. The present state-of-art paper describes the theoretical background of this method and the applications to cold-formed steel sections in compression and bending. Special attention is paid to the evaluation methods of erosion coefficient and to their validation. The ECBL approach can be also used to the plastic-elastic interactive buckling of thin-walled members, and the paper provides significant results on this line.

The Design and Implementation of Electromotion Curtain System using PLC and CDM Controller

  • Choo, Yeon-Gyu;Kang, Sung-Soo;Kim, Bong-Gi
    • Journal of information and communication convergence engineering
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    • v.8 no.4
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    • pp.443-448
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    • 2010
  • The electrical curtain is an electronic product which is most suitable for the sphere of intelligent home network. It provides the basic feature of intelligent home network such as the followings; various functions, powerful control. It also becomes the ideal technology with inexpensive power-line protocol, energy saving and solar power generation. Generally it is a suitable motor for BLDC to move the electrical curtain, because it provides the maintenance without difficulty, long-lived use with good efficiency. On this paper, we proposed the BLDC motor controller designed by CDM(Coefficient Diagram Method) and evaluated its performance with a simulation of the plant, designed the electrical curtain using BLDC motor and powe-line protocol.

A study on the Motions of a ship with Liquid Cargo Tanks (화물창의 유체유동을 고려한 선체운동에 관한 연구)

  • 박명규;김순갑;김동준
    • Journal of the Korean Institute of Navigation
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    • v.10 no.2
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    • pp.139-155
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    • 1986
  • In this paper the dynamic effects due to the free water motions in tanks upon the lateral motion of a floating body in regular waves are calculated, in order to obtain the relationship between a motion of a floating body and that of the free water in tanks. Under the assumption that the fluid is ideal and motion amplitudes are small, velocity potential of the fluid in tanks is calculated by the source distribution method and the hydrodynamic forces and moments are calculated by the integration of fluid pressures over the tank surface. Hydrodynamic effects of the fluid on the floating body are expressed in terms of added mass and coupling coefficient obtained from the integration. Computations are carried out for ship with seven wide center tanks and comparisons between the liquid cargo loading case and the rigid cargo loading case are shown.

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SVM Load Forecasting using Cross-Validation (교차검증을 이용한 SVM 전력수요예측)

  • Jo, Nam-Hoon
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.55 no.11
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    • pp.485-491
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    • 2006
  • In this paper, we study the problem of model selection for Support Vector Machine(SVM) predictor for short-term load forecasting. The model selection amounts to tuning SVM parameters, such as the cost coefficient C and kernel parameters and so on, in order to maximize the prediction performance of SVM. We propose that Cross-Validation method can be used as a model selection algorithm for SVM-based load forecasting technique. Through the various experiments on several data sets, we found that the difference between the prediction error of SVM using Cross-Validation and that of ideal SVM is less than 5%. This shows that SVM parameters for load forecasting can be efficiently tuned by using Cross-Validation.

The Design and Implementation of Electromotion Curtain System using BLDC Motor (BLDC 모터를 이용한 전동커튼시스템 설계 및 구현)

  • Choo, Yeon-Gyu;Kim, Bong-Ki
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.05a
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    • pp.763-766
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    • 2009
  • The electrical curtain is an electronic product which is most suitable for the sphere of intelligent home network. It provides the basic feature of intelligent home network such as the followings; various functions, powerful control. It also becomes the ideal technology with inexpensive power-line protocol, energy saving and solar power generation. Generally it is a suitable motor for BLDC to move the electrical curtain, because it provides the maintenance without difficulty, long-lived use with good efficiency. On this paper, we proposed the BLDC motor controller desinged by CDM(Coefficient Diagram Method) and evaluated its performance with a simulation of the plant, designed the electrical curtain using BLDC motor and powe-line protocol.

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A Study on Digital Filter Design based on High-order Window Function (고차 창함수 기반의 디지털필터 설계에 관한 연구)

  • Bae, Sang-Bum;Kim, Nam-Ho
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2009.10a
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    • pp.973-976
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    • 2009
  • Digital signal processing technique use to variety fields including communication. For these signal processing, FIR digital filter is representative. And for FIR digital filter designing, the window function is used to reduce the Gibbs phenomenon which occurs in the coefficient cutting process of the ideal filter. Therefore, in this paper to improve performance of digital filter, a high-order window function was applied. In this simulation, we compared a peak side-lobe and a transient characteristics with the existing window function.

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A review on thermomechanical properties of polymers and fibers reinforced polymer composites

  • Saba, N.;Jawaid, M.
    • Journal of Industrial and Engineering Chemistry
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    • v.67
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    • pp.1-11
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    • 2018
  • Polymer composites offered broad engineered applications, however their diversity get restricted owing to fluctuations in thermomechanical properties during heating or cooling hence great concern required prior their applications through thermomechanical analysis (TMA). Traditionally, TMA or dilatometry found to be simple, ideal, reliable, sensitive, excellent and basic thermal analytical technique. TMA provides valuable information on thermal expansion, glass transitions temperature (Tg), softening points, composition and phase changes on material of having different geometries simply by applying a constant force as a function of temperature. This compilation highlights the basics and experimental of TMA for both research and technical applications and also provide literature on TMA of polymers, hybrid composites, nanocomposites and their diverse applications.

Electrical Engineering Design Method Based on Neural Network and Application of Automatic Control System

  • Zhe, Zhang;Yongchang, Zhang
    • Journal of Information Processing Systems
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    • v.18 no.6
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    • pp.755-762
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    • 2022
  • The existing electrical engineering design method and the dynamic objective function in the application process of automatic control system fail to meet the unbounded condition, which affects the control tracking accuracy. In order to improve the tracking control accuracy, this paper studies the electrical engineering design method based on neural network and the application of automatic control system. This paper analyzes the structure and working mechanism of electrical engineering automation control system by an automation control model with main control objectives. Following the analysis, an optimal solution of controllability design and fault-tolerant control is figured out. The automatic control power coefficient is distributed based on an ideal control effect of system. According to the distribution results, an automatic control algorithm is based on neural network for accurate control. The experimental results show that the electrical automation control method based on neural network can significantly reduce the control following error to 3.62%, improve the accuracy of the electrical automation tracking control, thus meeting the actual production needs of electrical engineering automation control system.