• Title/Summary/Keyword: reaction concept

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Planar near-field antenna measurement method based on symplectic relation and reaction concept

  • Cho, Yong-Heui
    • International Journal of Contents
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    • v.6 no.2
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    • pp.6-9
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    • 2010
  • Using symplectic relation and reaction concept, we propose a planar near-field antenna measurement method. A generalized probe compensation equation is deduced to obtain the probe correction formulation. To verify our approach, a reflector antenna with $1{\times}2$ horn array is fabricated and measured in the near-field measurement facility. The near-field measurement results are compared with the physical optics (PO) simulation. The results of measurement and simulation agree very well near to the mainbeam.

REMARKS ON CRITERIA FOR THE EXISTENCE OF A POSITIVE EQUILIBRIUM IN REACTION NETWORKS

  • Choo, S.M.
    • Journal of applied mathematics & informatics
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    • v.29 no.3_4
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    • pp.949-953
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    • 2011
  • It is interesting to know the behavior of a network from its structure. One interesting topic is to find a relation between the existence of a positive equilibrium of the reaction network and its structure. One approach to study this topic is using the concept of deficiency. Another is using some conditions on nodes, which can apply to large-size networks compared to deficiency. In this work, we show the relation between deficiency and the conditions.

AN ELEMENTARY PROOF OF THE EXISTENCE OF A POSITIVE EQUILIBRIUM IN REACTION NETWORKS

  • Choo, S.M.
    • Journal of applied mathematics & informatics
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    • v.28 no.5_6
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    • pp.1545-1552
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    • 2010
  • It is interesting to know the behavior of a network from its structure. One interesting topic is to find a relation between the existence of a positive equilibrium of the reaction network and its structure. One approach to study this topic is using the concept of deficiency. In this work, we develop an algorithm and show an elementary proof of the relation based on the algorithm and deficiency.

The Effect of Apply Concept Maps for 'Ocean' Units in Middle School Science (중학교 과학 '해양' 단원의 개념도 활용 수업의 효과)

  • Choi, Sung-Bong
    • Journal of the Korean Society of Earth Science Education
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    • v.6 no.2
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    • pp.93-100
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    • 2013
  • The purpose of this study is to examine the effect of science related attitudes and science inquiry skill that apply concept maps for 'Ocean' units in middle school science. The subjects of this study consist of four classes third grade middle school students of the Busan Metropolitan City, which were divided into two groups: one is the experimental group which applied concept map teaching and the other is the ordinary teaching group. The result of this study were shown as follow: First, the use of concept map teaching improved the active meaningful process and improved student's science related attitudes in the experimental group. Second, the science lesson using concept map is effective for science inquiry skill in the experimental group. Third, the using concept map teaching created a positive reaction to make the formulation of ideas.

The Evaluation and Treatment of Post-Traumatic Stress Disorder and Acute Stress Disorder After Traumatic Brain Injury (외상성 뇌손상이후 발생하는 외상후 스트레스장애와 급성스트레스 장애의 평가 및 치료)

  • Park, Ki-Chang
    • Korean Journal of Biological Psychiatry
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    • v.2 no.2
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    • pp.193-204
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    • 1995
  • Traumatic brain injury(TBI) used to be developed after a severe traumatic event. Therefore TBI usually induces acute or chronic stress reaction. I reviewed the concept, epidemiology, biological or psychosocial etiology, diagnosis and treatment of post-traumatic stress disorder (PTSD), and discussed about PTSD or stress reaction after TBI. Early evaluation and management of stress reaction after TBI are important.

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Catalytic Activity Tests in Gas-Liquid Interface over Cu-ZnO/Al2O3 Catalyst for High Pressure Water-Gas-Shift Reaction (고압 WGS 반응을 위한 Cu-ZnO/Al2O3 촉매상에서 기-액 계면 촉매 반응 특성 연구)

  • Kim, Se-Hun;Park, No-Kuk;Lee, Tae-Jin
    • Transactions of the Korean hydrogen and new energy society
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    • v.22 no.6
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    • pp.905-912
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    • 2011
  • In this study, the novel concept catalytic reactor was designed for water-gas shift reaction (WGS) under high pressure. The novel concept catalytic reactor was composed of an autoclave, the catalyst, and liquid water. Cu-ZnO/$Al_2O_3$ as the low temperature shift catalyst was used for WGS reaction. WGS in the novel concept catalytic reactor was carried out at the ranges of 150~$250^{\circ}C$ and 30~50 atm. The liquid water was filled at the bottom of the autoclave catalytic reactor and the catalyst of pellet type was located at the gas-liquid water interface. It was concluded that WGS reaction occurred over the surface of catalysts partially wetted with liquid water. The conversion of CO for WGS was also controlled with changing content of Cu and ZnO used as the catalytic active components. Meanwhile, the catalyst of honey comb type coated with Cu-ZnO/$Al_2O_3$ was used in order to increase the contact area between wet-surface of catalyst and the reactants of gas phase. It was confirmed from these experiments that $H_2$/CO ratio of the simulated coal gas increased from 0.5 to 0.8 by WGS at gas-liquid water interface over the wet surface of honey comb type catalyst at $250^{\circ}C$ and 50 atm.

Development of A Simple Design Monograph for Track Sublayers (궤도 하부구조설계를 위한 간이 설계 모노그래프 개념 개발)

  • Park, Mi-Yun;Lee, Jin-Ug;Lee, Seong-Hyeok;Park, Jae-Hak;Lim, Yu-Jin
    • Proceedings of the KSR Conference
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    • 2011.10a
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    • pp.428-435
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    • 2011
  • In general, thickness of the sublayers under track is designed based on concept of vertical soil reaction value or vertical stiffness. However, this design method cannot take consideration into soil-track interaction under repetitive load, traffic condition and velocity of the train. Furthermore, the reinforced roadbed soils experience complex behavior that cannot be explained by conventional stress-strain relation expressed as soil reaction value k. The reinforced roadbed soils also can produce cumulative permanent deformation under repetitive load caused by train. Therefore new design method for the sublayers under track must be developed that can consider both elastic modulus and permanent deformation. In this study, a new design concept, a rule-of-thumb, is proposed as the form of design monograph that is developed using elastic multi-layer and finite element programs by analyzing stress and deformation in the sublayers with changing the thickness and elastic modulus of the sublayers and also using data obtained from repetitive triaxial test. This new design concept can be applied to design of the reinforced roadbed before developing full version of design methodology that can consider MGT, axial load and the material properties of the layers. The new design monograph allows the user to design the thickness of the reinforced roadbed based on permanent deformation, elastic modulus and MGT.

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An Introduction on the Customer Reaction Encouragement System for E-Commerce Customer Satisfaction : Extension of Customer Response System (전자상거래 고객만족을 위한 고객반응유도시스템 도입 : 고객응대시스템의 확장을 중심으로)

  • 서순모;이종호
    • The Journal of Society for e-Business Studies
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    • v.9 no.1
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    • pp.237-254
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    • 2004
  • A customer satisfaction at business activity has influence on affirmative customer reaction. The customer reaction encouragement system(CRES) is to expand the present customer response concept in this paper. The CRES application can make real-time connection between customers and sellers at EC(B2C) environment, and on the basis of this application, it can derive the positive customer reaction encouragement. In this paper, the comparison results between new EC system applied for the CRES and present EC system are proposed.

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Numerical Investigation on the Thermal Characteristics of Mild Combustion According to Co-axial Air (동축공기에 따른 Mild 연소의 열적 특성에 대한 수치연구)

  • Hwang, Chang-Hwan;Baek, Seung-Wook;Kim, Hak-Young
    • Journal of the Korean Society of Combustion
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    • v.15 no.4
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    • pp.1-8
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    • 2010
  • Mild combustion is considered as a promising combustion technology for energy saving and low emission of combustion product gases. In this paper, the controllability of reaction region in mild combustion is examined by using co-axial air nozzle. For this purpose, numerical approach is carried out. Propane is considered for fuel and air is considered for oxidizer and the temperature of air is assumed 900K slightly higher than auto ignition temperature of propane. But unlike main air, the atmospheric condition of co-axial air is considered. Various cases are conducted to verify the characteristics of Co-Axial air burner configuration. The use of coaxial air can affect reaction region. These modification help the mixing between fuel and oxidizer. Then, reaction region is reduced compare to normal burner configuration. The enhancement of main air momentum also affects on temperature uniformity and reaction region. The eddy dissipation concept turbulence/chemistry interaction model is used with two step of global chemical reaction model.