• Title/Summary/Keyword: substitution

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Ba치환이 PMN-PZT세라믹의 전기적, 유전적 특성에 미치는 영향 (Effects of Ba substitution on the electric, dielectric properties of PMN-PZT Ceramics)

  • 김만성;류주현;이수호
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1997년도 추계학술대회 논문집
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    • pp.158-162
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    • 1997
  • In this paper, the electrical and dielectrical properties were investigated in Pb(Zr,Ti)O$_3$-Pb(Mn,Nb)O$_3$ ceramics which are manufactured with the substitution of Ba in site Pb. In older to increase the del and Kp , Ba was substitued to site Pb from 0 to 0.1 by 0.02 mol%. As the Ba substitution is increased, dielectric constant is increased and electricmachanical coupling factor showed the maximum value at Ba 0.06mol% and the mechanical qualify factor is decreased and the tetragonality and the grain size are decreased as the Ba substitution.

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Dollarization in North Korea: Evidence from a Survey of North Korean Refugees

  • Mun, Sung Min;Jung, Seung Ho
    • East Asian Economic Review
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    • 제21권1호
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    • pp.81-100
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    • 2017
  • This study measures the degree of dollarization in North Korea using results from a survey of 231 North Korean refugees. Specifically, we compare foreign currency use of households as both store-of-value substitutes (i.e., asset substitution) and transaction substitutes (i.e., currency substitution) before and after the confiscatory currency reform of 2009. The degree of dollarization has advanced since the currency reform in terms of both asset and currency substitutions. Survey results also indicate that the Chinese yuan is frequently used in the Sino-North Korean border area, whereas the US dollar is predominantly used in non-border areas. Furthermore, foreign currency increasingly serves as a medium of exchange not only for large transactions but also for smaller transactions, such as food purchases.

A Study of Unit Commitment Considering Environmental Effects by Fuel Substitution

  • Lee, Buhm;Kim, Yong-Ha;Park, Nam-Sup
    • Journal of information and communication convergence engineering
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    • 제1권2호
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    • pp.93-97
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    • 2003
  • This paper proposes a new generation scheduling algorithm which can consider total quantity of contamination and energy limits based on Lagrangian Relaxation. First, we formulate a Lagrangian function which consider quantity of contamination including substitution of fuel, and quantity of fuel. Second, we developed Multi-state S.U.D.P. which can treat multiple fuels. Third, we propose an effective generation scheduling algorithm including Multi-state S.U.D.P.. As a results, unit commitment and generating power can be obtained to meet the environmental and fuel constraints with fuel substitution. By applying it to the test system, effectiveness of the method is verified.

Elasticity of substitution of renewable energy for nuclear power: Evidence from the Korean electricity industry

  • Kim, Kwangil
    • Nuclear Engineering and Technology
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    • 제51권6호
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    • pp.1689-1695
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    • 2019
  • This study suggests a simple economic model to analyze electricity grid that consists of different power sources. The substitutability of renewable energy for nuclear power in Korean electricity transmission network is investigated by suggested model. The monthly data from January 2006 to December 2013 reported by Electricity Power Statistics Information System (EPSIS) of Korea Power EXchange (KPX) are used. To estimate the elasticities of substitution among four power sources (i.e. coal, natural gas, nuclear power, and renewable energy), this paper uses the trans-log cost function model on which local concavity restrictions are imposed. The estimated Hicks-Allen and Morishima elasticity of substitution shows that renewable electricity and nuclear power are complementary. The results also evidenced that renewable electricity and fossil fueled thermal power generation are substitutes.

Isomorphous Substitution of Fe in Sodalite and Its Electric Characterization

  • Kim, Chy-Hyung;Jung, Chi-Sup
    • Bulletin of the Korean Chemical Society
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    • 제14권2호
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    • pp.215-220
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    • 1993
  • Experiment on isomorphous substitution of Al by Fe in sodalite framework was carried out using dry way method at 800-900$^{\circ}$C in nitrogen atmosphere. The substitution of Fe was possible up to 25 mole% with some deviation of symmetry in sodalite cage. The cubic unit cell parameter increased with increasing Fe content. It showed ionic semiconducting property, especially the highest conductivity and the lowest activation energy in 10 mole% Fe-substituted sodalite which could behave as a superionic conductor at above 400$^{\circ}$C. When more Fe was introduced into sodalite the electronic conductivity was improved at high temperature. But the relative electronic contribution was found to be lower compared with ionic contribution at high temperature. In infrared spectra some major absorption bands of sodalite shifted to lower wave numbers due to heavier Fe atoms substitution in Al lattice sites.

Generation Z and Its OTT Usage Patterns: The Case of Netflix in Korea

  • Ahn, Jungah
    • International Journal of Contents
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    • 제18권1호
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    • pp.65-75
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    • 2022
  • This study aims to reveal the various differences within the factors that influence use satisfaction, continuous use intention, and media substitution intention, specifically in regard to the use motives and use behaviors of Netflix viewers. This study's results demonstrate that the following various factors affected use satisfaction, continuous use intention, and media substitution intention in differential ways. Firstly, the diversity of content influenced use satisfaction to a greater degree than social relations; and the diversity of content, social relations, and active participation all positively influenced continuous use intention. In other words, the more positively users appreciated the diversity of content, and the more strongly they had social relations, and the more actively they participated within communities, the greater degree to which they increased their continuous use intention for Netflix. However, the diversity of content and the convenience of use also had a negative effect on the media substitution intention for Netflix, which means that the more diverse the content and the more convenient the use of Netflix, the fewer the number of users who intended to cancel Netflix and subscribe to another OTT service or resubscribe to traditional media sources.

초월대수 비용함수 추정을 통한 IATTC 해역 원양연승어업의 생산요소 간 대체성 분석 (Substitution analysis among production factors of distant longline fisheries in IATTC waters using a translog cost function)

  • 조헌주;김도훈;김두남;이성일;이미경
    • 해양정책연구
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    • 제34권2호
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    • pp.1-28
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    • 2019
  • The purpose of this study is to analyze the substitution among production factors of Korean distant water longline fisheries in IATTC waters. In the analysis, the translog function which have one output variable of total cost and input variables of labor, fuel, fishing gear, and capital was established and it was transformed into simultaneous equations by each cost. Then, variables of equations were estimated by SUR (seemingly unrelated regression) model. Since distant water longline fisheries is a fishing type with high fuel usage, substitution of fuel with other factors was mainly analyzed. Results showed a substitute relation between fuel and labor as well as fuel and fishing gear, while a complementary relation between fuel and capital. In addition, it was analyzed that magnitude of fuel elasticity with other factors would be inelastic.