• Title/Summary/Keyword: Generation difference

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The Comparative Study on Consumer's Purchase Behaviors by Sexuality (성별에 따른 외식구매행동 비교연구 - 20대 초반 대학생을 중심으로 -)

  • Jin, Yang-Ho
    • Culinary science and hospitality research
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    • v.13 no.1 s.32
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    • pp.224-234
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    • 2007
  • Consumers' awareness has been changing through the development of information industry and change of life style. To understand the new generation came to be our concern in terms of being able to predict the trend of the future. Companies are trying to go through the market-change by making a marketing strategy that matches their emotion and characteristics. There should be a research on the new generation, specially university students, according to sex. Therefore, this research covers the university students in early twenties to see the differences between sexes. Foodservice industry needs to have consideration on coupon-books. It is reconfirmed that advertisement by word of mouth is still effective in sales promotion.

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Numerical Study of Thermal Convection in Horizontal Enclosure with Heat Generating Conducting Body (발열 전도체를 가지는 밀폐계 내부의 자연대류 현상에 대한 수치적 연구)

  • Lee, Jae-Ryong;Ha, Man-Yeong
    • Proceedings of the KSME Conference
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    • 2004.11a
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    • pp.1080-1085
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    • 2004
  • The physical model considered here is a horizontal layer of fluid heated below and cold above with heat-generating conducting body placed at the center of the layer. The dimensionless thermal conductivities of body considered in the present study are 0.01, 1 and 150. The dimensionless temperature difference ratios considered are 0.25, 2.5 and 25. Two-dimensional solution for unsteady natural convection is obtained using an accurate and efficient Chebyshev spectral methodology for variety of Rayleigh number from $10^{3}$ to $10^{6}$. Multi-domain technique is used to handle square-shaped heat-generating conducting body. The results for the case of conducting body with heat generation are also compared to those without heat generation.

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The Coupling of Conduction with Free Convection Flow Along a Vertical Flat Plate in Presence of Heat Generation

  • Taher, M.A.;Lee, Yeon-Won
    • Journal of Advanced Marine Engineering and Technology
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    • v.31 no.7
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    • pp.833-841
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    • 2007
  • The aim of this paper is to analyze the conjugate problems of heat conduction in solid walls coupled with laminar free convection flow adjacent to a vertical flat plate under boundary layer approximation. Using the similarity transformations the governing boundary layer equations for momentum and energy are reduced to a system of partial differential equations and then solved numerically using Finite Difference Method(FDM) known as the Keller-box scheme. Computed solutions to the governing equations are obtained for a wide range of non-dimensional parameters that are present in this problem, namely the coupling parameter P. the Prandtl number Pr and the heat generation parameter Q. The variations of the local heat transfer rate as well as the interface temperature and the friction along the plate and typical velocity and temperature profiles in the boundary layer are shown graphically. Numerical solutions have been consider for the Prandtl number Pr=0.70

An Application of Divisia Decomposition Analysis to the Measurement of Thermal Efficiency Improvement of Power Generation (화력발전소 효율개선 측정에 대한 디비지아분해기법의 적용)

  • Choi, Ki-Hong
    • Environmental and Resource Economics Review
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    • v.9 no.5
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    • pp.811-827
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    • 2000
  • Since improved thermal efficiency reduces capacity requirements and energy costs, electricity producers often treat thermal efficiency as a measure of management or economic performance. The conventional measure of the thermal efficiency of a fossil-fuel generation system is the ratio of total electricity generation to the simple sum of energy inputs. As a refined approach, we present a novel thermal efficiency measure using the concept of the Divisia index number. Application of this approach to the Korean power sector shows improvement of thermal efficiency of 1.1% per year during 1970-1998. This is higher than the 0.9% improvement per year given by the conventional method. The difference is attributable to the effect of fuel substitution. In the Divisia decomposition context, we also show the limitations of the popular $T{\ddot{o}}rnqvist$ index formula and the superiority of the Sato-Vartia formula.

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Development of a Method for Reliability Evaluation of Transmission System under the Deregulated Electricity Market (규제완화된 전력시장 하에서의 송전계통 신뢰도 평가방법의 개발)

  • Cha, Jun-Min;Kim, Hong-Sik;Choi, Jae-Seok;Oh, Kwang-Hae
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.397-399
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    • 2000
  • This paper presents a method for assessing reliability indices of transmission system. Because successful operation of electric power under the deregulated electricity market depends on transmission system reliability management, quantity evaluation of transmission system reliability is very important. The key point idea is based on that the reliability level of transmission system is equal to reliability level difference of between composite power system(HLII) and generation system(HLI). It is sure that risk indices of reliability of composite power system are larger than those of generation system. It is the reason that composite power system includes uncertainties and capacity limit of transmission lines. The characteristics and effectiveness of this methodology are illustrated by the case study using MRBTS.

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The Socialization and the Comparison of Generation Attitudes about the Family Rituals (가정행사의 사회화 실태와 모녀세대간 시행의식 -진주시 여대생 가정을 중심으로-)

  • 장상옥
    • Journal of Families and Better Life
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    • v.21 no.5
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    • pp.41-50
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    • 2003
  • The purpose of this study is to investigate the level of the socialization of family rituals and compare the attitudes between the younger and the older generation. Research data were collected in 2002 from households living in Jinju. The subjects of this study were college students and their mothers. The results of this study were as follows: The socialization of the following family rituals is increasing: the first birthday party, banquets for parents' 60th birthday, wedding anniversaries, employment ceremony, and commencement ceremony. There was significant difference in the attitude between younger and older generations regarding performance of the family rituals.

A Study of Thermoelectric Material for Waste Heat Recovery (배열회수 발전용 열전소재 기초연구)

  • Kim, Ho-Young;Kim, Cham
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.175-180
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    • 2008
  • Thermoelectric materials convert temperature difference to electric power for power generation and vice versa for refrigeration. Recent advances in enhancing the thermoelectric figure-of-merit shed light on efficient power generation from the waste heat available in industries and vehicles. Nanoscale phenomena with both nanoscale constituent-embedded bulk samples and nanoscale materials proving enhanced thermoelectric performance have been widely reviewed. Bulk materials of crystal-orientation and nano-structured particle embedding seem to promise a higher thermoelectric figure-of-merit and an effective power generation application. As a preliminary study, Si-Ge nanocomposite was prepared with spark plasma sintering method and its properties were examined.

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A Protection Technique Against the Damages Caused by Lightning Surges on Information and Communication Facilities

  • Lee, Bok-Hee;Kang, Sung-Man;Ahn, Chang-Hwan
    • KIEE International Transactions on Electrophysics and Applications
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    • v.3C no.4
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    • pp.117-122
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    • 2003
  • The AC power lines and signal lines of info-communication networks are routed on overhead poles and are highly exposed to lightning strikes. Due to the potential difference between grounding points of AC power lines and signal lines, the electronic equipments connected to the signal lines can easily be damaged by lightning surges. In this work, in order to develop reliable methods of protecting information and communication facilities from lightning surges, the reliability and performance of SPDs (surge protective devices) were experimentally investigated in an actual-sized test circuit. The behaviors of SPDs against lightning surges from AC power lines and signal lines and the coordinated effects of SPD installation methods were evaluated. As a consequence, it was confirmed that the bypass arrester methods and common grounding system are both highly effective.

The Performance, Socialization and the Comparison of Generation Attitudes about the Family Rituals (여대생 가정의 가정행사 수행 및 사회화와 행사의식 변화 -최근 10년간 변화를 중심으로-)

  • 장상옥
    • Journal of Families and Better Life
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    • v.22 no.5
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    • pp.253-264
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    • 2004
  • The objective of this study was to investigate the change of the level of the performance of family rituals and socialization of them, and to compare the change of the attitudes between daughter and mother generation. Research data were collected in 1992 and 2002 from families living in Seoul. Housewives and university students from these families completed the questionnaires. Major findings were as follows: Most of the family performed the birthday parties, traditional rituals, and memorial days. The level of the performance of the birthday rituals, and rituals from western culture has increased for a decade. The socialization of the following family rituals is increasing: banquets for parents' 60th birthday, wedding anniversaries, employment ceremony, commencement ceremony. There was significant difference in the attitude between younger and older generations regarding performance of the family rituals between 1992 and 2002.

Performance Evaluation of Combined Heat and Power Plant Configurations -Thermodynamic Performance and Simplified Cost Analysis (열병합 발전소의 구성안별 성능 평가 방안 - 플랜트 열성능 및 단순화 발전단가 분석)

  • Kim, Seungjin;Choi, Sangmin
    • Journal of the Korean Society of Combustion
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    • v.18 no.3
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    • pp.1-8
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    • 2013
  • Thermodynamic and economic analyses of various types of gas turbine combined cycle power plants have been performed to establish criteria for optimization of power plants. The concept of efficiency, in terms of the difference in energy levels of electricity and heat, was introduced. The efficiency of power and heat generation by power plants with other purposes was estimated, and power generation costs were figured out for various types of combined heat and power plants(i.e., fired and unfired, condensing and non-condensing modes, single or double pressure HRSG).