• Title/Summary/Keyword: generation gap

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Effect of Tip Gap Height on Heat/Mass Transfer over a Cavity Squealer Tip (팁간극높이가 전면스퀼러팁 표면의 열전달 특성에 미치는 영향)

  • Kang, Dong Bum;Moon, Hyun Suk;Lee, Sang Woo
    • The KSFM Journal of Fluid Machinery
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    • v.16 no.6
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    • pp.19-25
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    • 2013
  • The effect of tip gap height on heat/mass transfer characteristics on the floor of cavity squealer tip has been investigated in a turbine cascade for power generation by employing the naphthalene sublimation technique. The squealer rim height is chosen to be an optimal one of $h_{st}/c$ = 5.51% for the tip gap height-to-chord ratios of h/c = 1.0, 2.0, 3.0 and 4.0%. The results show that heat transfer on the cavity floor is strongly dependent upon the behavior of the cavity flow falling down onto the floor. For lower h/c, the floor heat transfer is influenced by the tip leakage flow falling down along the inner face of the suction-side squealer, whereas the floor heat transfer for higher h/c is augmented mainly due to the impingement of leakage flow on the floor near the leading edge. Compared to the plane tip surface heat transfer, the cavity floor heat transfer is less influenced by h/c. For h/c = 1.0%, the average thermal load is as low as a half of the plane tip surface one, and the difference in the thermal load between the two cases tends to decrease with increasing h/c.

3D Numerical Simulation of Water Surface Variations and Velocity Fields around Permeable Submerged Breakwaters under Irregular Waves (불규칙파 조건 하에서 투과성잠제 주변의 수면변동 및 유속장에 관한 3차원 수치모의)

  • Lee, Kwang-Ho;Bae, Ju-Hyun;An, Sung-Wook;Kim, Do-Sam
    • Journal of Korean Society of Coastal and Ocean Engineers
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    • v.30 no.4
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    • pp.153-165
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    • 2018
  • In this study, the performance of irregular wave field generation of olaFlow is first verified by comparing the frequency spectrum of the generated waves by the wave-source using olaFlow and the target wave. Based on the wave performance of irregular waves of olaFlow, the characteristics of the velocity field including the average flow velocity, longshore current and turbulent kinetic energy around the three-dimensional permeable submerged breakwaters, which act as the main external forces of the salient formation, are numerically investigated. The numerical results show that as the gap width between breakwaters decreases, the wave height in the center of the gap increases and as the gap width between breakwaters increases, the longshore currents become stronger. As a result, it is possible to understand the formation of the salient formed behind the submerged breakwaters.

Analysis on the Discharge Characteristics of New Cell Structure for Luminous Efficacy Improvement in an AC Plasma Display Panel (교류형 플라즈마 표시키의 발광 효율 개설을 위한 실 구조의 방전 특성 분석)

  • Bae, Hyun-Sook;Whang, Ki-Woong
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.22 no.6
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    • pp.7-13
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    • 2008
  • Through two-dimensional numerical simulations, we analyzed the effects of new cell structure for the luminous efficacy improvement in an ac plasma display panel. In the new structure with 5 electrodes, two auxiliary electrodes are arranged between X and Y electrodes with long gap. Through the application of adequate auxiliary pulse on the address electrode, the luminous efficacy in the new cell structure showed the improvement of 52[%] in comparison with that of conventional cell structure with short gap between X and Y electrodes. Consequently, as the short gap discharge between auxiliary electrodes decreases and the long gap discharge between X and Y electrodes increases, the result of VUV generation efficacy shows higher improvement. The reliability of simulation result could he confirmed by the experimental result in the test panel.

A Study on the Factors Affecting Gender Wage Difference in the Creative Class (창조계층 성별 임금격차에 영향을 주는 요인 연구)

  • Joo, Mijin
    • The Journal of the Korea Contents Association
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    • v.19 no.2
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    • pp.248-258
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    • 2019
  • The importance of the creative class has been emphasized as the industrial structure changes. However, there are only a few studies on gender wage difference in the creative class. The purpose of this study is to analyze the various factors influencing the gender wage gap in the creative class by using labor panel data. The results of this study are as follows: First, it was found that the wage of the male creative class is higher than the wage of the female creative class. Second, there were different factors affecting wages depending on the gender of the creative class. Third, female workers in the creative class suffer wage discrimination due to differences, but a larger part is due to gender discrimination. Fourth, compared to the non-creative classes, the gender wage gap of the creative classes was small. The gender gap caused by discrimination was the highest among the younger generation.

An Analysis of the Meaning of Laughter by Comedians Hee-Gap Kim, Bong-Seo Koo and Young-Chun Seo : focusing on Korean Comedy Movies in the late 1960s (코미디언 김희갑, 구봉서, 서영춘의 웃음 의미작용 분석 : 1960년대 후반기 한국 코미디영화를 중심으로)

  • Seo, Kok-Suk
    • Journal of Korea Entertainment Industry Association
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    • v.15 no.8
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    • pp.75-89
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    • 2021
  • In this paper, the results of analyzing the meaning of laughter in comedy movies of the late 1960s, focusing on comedians, Hee-Gap Kim, Bong-Seo Koo and Young-Chun Seo, are as follows. First, the narrative laughter of the comedians represents the generational conflict between the lower class and the upper class, the gender conflict between men and women, and the frustration of reality. Second the mechanism of creating laughter of the comedians shows ridicule of the conservative older generation, revelation of the immoral upper class, and caricature of the frustrated lower class. Third, the practical aspect of the comedians' laughter reveals cracks in tradition and modern, gaps in economic inequality, and expression of prohibited desires. Therefore, comedians Hee-Gap Kim, Bong-Seo Koo and Young-Chun Seo in comedy movies of the late 1960s show the semantic effect of laughter of internal/external boundaries and optimistic world views through the closed opening of informal culture and the conflict of characters/performers.

LCOE Assessment of Major Power Generation Technologies Reflecting Social Costs (사회적 비용을 고려한 국내 주요 발전기술의 균등화발전비용 산정)

  • Cho, Young-Tak;Seok, Kwanghoon;Park, Jong-Bae
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.67 no.2
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    • pp.179-185
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    • 2018
  • A considerable cost gap between three major power generation technologies, namely nuclear, coal, and combined cycle gas turbine (CCGT), has been a well-established fact in the Korean electricity market. Alternatively, this paper analyzes the levelized costs of electricity (LCOE) of the three technologies reflecting overall social costs of electricity generation including accident risk, $CO_2$ emission, and air pollution damage. The paper unveils to what extent current discriminative subsidies on fuels regarding the social costs, mostly through tax exemptions, affect economic competitiveness of the technologies. In particular, it finds relative positions of coal and CCGT could be altered depending on appreciation level of the social costs. It has limits in analyzing fixed costs of the technologies, however, due to limited data availability of nuclear power, and suggests further studies on the issue.

A Study of Virtual 3D Fashion Coordination (가상 3D 패션 코디네이션 연구)

  • 강인애;김효숙;최창석
    • Journal of the Korean Home Economics Association
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    • v.40 no.6
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    • pp.159-171
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    • 2002
  • Today, many people seek for their own personal character which is distinguished from another people and they utilize fashion coordination as the was of expression their own image. In addition, interest in electronic commerce and cuber shopping mall on the internet is increasing. For this reason, visual and interesting virtual fashion coordination system is needed. The purpose of this study is to propose possibility of fashion coordination by virtual 3D model. For this study, 1. We make a 3D standard body model by automatic generation. 2. We make 3D fashion item (sleeveless top and flare skirt) by automatic generation. 3. We combine 3D body model with fashion item by special point, grouping and gap being between body and clothes. 4. We make textile palettes and textile DB for texture mapping and rendering. As a effect of this study, 1. It can give the chance to coordinate clothes suitable for their own character and bodyshape on the cuber space more speedily and variously. 2. It can help fashion internet shopping mall company can save a time, expenses and tries to advertise their new products, offer service for customers and lead customers to purchasing. 3. It can accumulate a database of design and textile for using by fashion and textile industry.

Improvement of Ozone Yield by a Multi-Discharge Type Ozonizer Using Super position of Silent Discharge Plasma (무성방전의 중첩을 이용한 다중방전형 오존발생기의 오존생성수율 개선)

  • Song, Hyun-Jig;Lee, Dong-Heon;Oh, Jin-Hoon;Park, Seong-Wook;Seo, Young-Taek
    • Proceedings of the KIEE Conference
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    • 2004.07e
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    • pp.88-91
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    • 2004
  • In order to improve ozone generation, we experimentally investigated the silent discharge plasma and ozone generation characteristics of a multi-discharge type ozonizer. Ozone in a multi-discharge type ozonizer is generated by superposition of a silent discharge plasma, which is simultaneously generated in separated discharge spaces. A multi-discharge type ozonizer is composed of three different kinds of superposed silent discharge type ozonizers, depending on the method of applying power to each electrode. We observed that the discharge period of the current pulse for a multi-discharge type ozonizer can be longer than that of silent discharge type ozonizer with two electrodes and one gap.Hence, ozone generation is improved up to 17185 ppm and 783 g/kwh for the superposed silent discharge type ozonizer for which an AC high voltages with a 180 phase difference were applied to the internal electrode and the external electrode, respectively, with the central electrode being ground

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A Study on the Characteristics of Discharge and Ozone Generation for Ozonizer of Neon Discharge Tube Type (네온방전관형 오존발생기의 방전특성 및 오존생성특성에 관한 연구)

  • Song, H.J.;Woo, S.H.;Kim, S.G.;Kim, K.C.;Lee, K.S.;Lee, D.I.
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1857-1860
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    • 1996
  • In this paper, ozonizer of neon discharge tube type( Neolamp ) by using silent discharge has been designed and manufactured. The discharge and ozone generation characteristics of Neolamp have been studied with variation of turn-on number( N ) of Neolamp, quality( Q ) and shape of external electrode. The discharge voltage is proportional to gap spacing of spiral external electrode( G ) for constant applied volatge. The discharge current is inversely proportional to G for constant applied volatge. The ozone concentration is inversely proportional to Q and G. Also, ozone concentration and generation are proportional to N. The sterilization characteristics of Escherichia coil have been obtained more than 97[%] at $1.30[mg/{\ell}]$ of liquid ozone concentration.

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Corona Discharge and Ozone Generation Characteristics of a Wire-to-Wire Gap with a Ferroelectric Pellet Bed (강유전체 충진 선대선 방전갭의 코로나 방전 및 오존 발생특성)

  • Shin, Jung-Min;Bae, Chang-Hwan;Ahn, Chang-Jin;Lee, Jong-Hoon;Moon, Jae-Duk
    • Proceedings of the KIEE Conference
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    • 2003.07c
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    • pp.1873-1875
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    • 2003
  • Surface corona discharge characteristics of a ac corona charged ferroelectric pellet barrier have been investigated experimentally. Electric charged stored on the surfaces of the ferroelectric pellets by a at corona discharge provide partial electric fields on the surfaces of the ferroelectric pellets, which could generate surface corona discharges on the ferroelectric pellets. This system utilizes both the surface discharges on the ferroelectric pellet barrier and the corona discharge between wire electrodes. As a result, in the case of the corona discharge with the ferroelectric pellet barrier, the mean corona current and ozone generation increase greatly, and the surface discharges on the ferroelectric pellets can be generated efficiently. It is also found that, the ferroelectric pellet barrier discharge reactor had better discharge characteristics for plasma generation than the wire-to-wire discharge reactor without pellets.

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