• Title/Summary/Keyword: RECC

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Urban Change Detection Between Heterogeneous Images Using the Edge Information (이종 공간 데이터를 활용한 에지 정보 기반 도시 지역 변화 탐지)

  • Jae Hong, Oh;Chang No, Lee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.33 no.4
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    • pp.259-266
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    • 2015
  • Change detection using the heterogeneous data such as aerial images, aerial LiDAR (Light Detection And Ranging), and satellite images needs to be developed to efficiently monitor the complicating land use change. We approached this problem not relying on the intensity value of the geospatial image, but by using RECC(Relative Edge Cross Correlation) which is based on the edge information over the urban and suburban area. The experiment was carried out for the aerial LiDAR data with high-resolution Kompsat-2 and −3 images. We derived the optimal window size and threshold value for RECC-based change detection, and then we observed the overall change detection accuracy of 80% by comparing the results to the manually acquired reference data.

Behavior of short columns constructed using engineered cementitious composites under seismic loads

  • Syed Humayun Basha;Xiaoqin Lian;Wei Hou;Pandeng Zheng;ZiXiong Guo
    • Steel and Composite Structures
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    • v.48 no.5
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    • pp.565-582
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    • 2023
  • The present research reports the application of engineered cementitious composites (ECC) as an alternative to conventional concrete to improve the seismic behavior of short columns. Experimental and finite element investigation was conducted by testing five reinforced engineered cementitious composite (RECC) concrete columns (half-scale specimens) and one control reinforced concrete (RC) specimen for different shear-span and transverse reinforcement ratios under cyclic lateral loads. RECC specimens with higher shear-span and transverse reinforcement ratios demonstrated a significant effect on the column lateral load behavior by improving ductility (>5), energy dissipation capacity (1.2 to 4.1 times RC specimen), gradual strength degradation (ultimate drift >3.4%), and altering the failure mode. The self-confinement effect of ECC fibers maintained the integrity in the post-peak region and reserved the transmission of stress through fibers without noticeable degradation in strength. Finite element modeling of RECC specimens under monotonic incremental loads was carried out by adopting simplified constitutive material models. It was apprehended that the model simulated the global response (strength and stiffness) and damage crack patterns reasonably well.

Preparation process of functional particles: II. Particle coating by rapid expansion of supercritical fluid solutions (기능성 미분말의 제조공정에 관한 연구: II. 초임계 분출법에 의한 입자 코팅)

  • 류완원;김영도;신건철
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.8 no.4
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    • pp.673-676
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    • 1998
  • The Rapid Expansion of Supercritical fluid Solutions (RESS) process was applied to particles coating. Experiments were conducted in a fluidized bed with an internal nozzle in the center of the reaction tube. Pure glass beads (500~590$\mu$m, 74~149$\mu$m) and glass beads covered with brilliant blue were used as the core particles. Supercritical $CO_2$ solutions of paraffin were expanded through the nozzle into the bed that was fluidized by air. The precipitate coating materials on core surface was analyzed by using SEM, FT-IR. The releasing behavior of brilliant blue was inspected by atomic absorbance spectrophotometer. The release behavior of coated particles superior to noncoated particles.

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Parallel Computing Simulation of Large-Scale Polymer Electrolyte Fuel Cells (대면적 고분자전해질연료전지의 병렬계산 시뮬레이션)

  • Gwak, Geon-Hui;Chippar, Purushothama;Kang, Kyung-Mun;Ju, Hyun-Chul
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.6
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    • pp.868-877
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    • 2011
  • This paper presents a parallel computing methodology for polymer electrolyte fuel cells (PEFCs) and detailed simulation contours of a real-scale fuel cell. In this work, a three-dimensional two-phase PEFC model is applied to a large-scale 200 $cm^2$ fuel cell geometry that requires roughly 13.5 million grid points based on grid-independence study. For parallel computing, the large-scale computational domain is decomposed into 12 sub-domains and parallel simulations are carried out using 12 processors of 2.53 GHz Intel core i7 and 48GB RECC DDR3-1333. The work represents the first attempt to parallelize a two-phase PEFC code and illustrate two-phase contours in a representative industrial cell.