• Title/Summary/Keyword: Mid-Gap

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The Research on the Development Procedure and Current Problems of the Korean Abalone Industry (전복 양식업의 발전과정과 당면과제 연구)

  • Ock, Young-Soo
    • The Journal of Fisheries Business Administration
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    • v.44 no.3
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    • pp.15-28
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    • 2013
  • Abalone aquaculture has developed very rapidly in Korea. Until the mid 1990s it has annually produced about 100 tons. Since then the yield has increased to about 9,000 tons in 2012. The amount accounts for 20% of the global abalone yield. About 86% of produced abalone is consumed domestically and the rest is exported. 100 tons for export seemed as an unattainable goal back in 2003. However, the export rose up to 1,333 tons in 2012. Despite its rapid growth, Korean abalone industry is faced with some problems. The first is the slowdown of yield increase rates. Abalone production increased by 50~60% until the mid 2000. However, the rate continued to drop to below 10%. Reasons behind the slow increase are deteriorating aquaculture grounds and worsening market problems. Constant aquaculture aggravated productivity and overcrowded facilities at a limited space made matters worse. Moreover, abalone export has stalled and so did domestic consumption. In the meantime, rising mortality of young abalone has lowered productivity at abalone breeding places. The mortality rates of abalone remained below 5% in the early 2000s but rose to 30~40% these days. This translates into rising abalone prices. The market problems imply stagnant or shrinking export as well as domestic consumption. The export increase rates took a nosedive from 200 to below 50 between the early 2000s and the late 2000s. Moreover, the increase rates of domestic consumption have become remarkably sluggish. According to, it stood at 50~60% in the mid 2000s but continued to decrease after 2008. These problems, in turn, affected the size of abalone. The usual abalone size for market was 10~12 shells per kg, but recently the size became smaller and smaller to 15~16 shells per kg. The change of size implies shift in consumption patterns: Consumers not only eat live abalone but also they cook soup with it. The size of abalone for uncooked dish is usually very big, like 10~12 shells per kg. In contrast, smaller abalone, such as 20~25 shells per kg, are used for making soup. Increasing use of smaller abalone leads to lower income of abalone aquaculture households. This is partly because that the size determines the price and the price gap between big abalones and smaller ones is extreme in Korea. For the sustainable growth of Korean abalone industry, we need to come up with strategies. First, a reasonable production system needs to be in place, especially for better management of abalone aquaculture grounds. Management of abalone licenses is also necessary because local governments issue relevant licenses as well as supervising abalone grounds. Second, abalone export destination need to be diversified. Japan, the major importer of Korean abalone, takes up a lion's share of export, at 95%. Third, new consumption style of abalone needs to be developed. Abalone used to be consumed as 'raw type' or Sashimi in Korea. This sole type of consumption hampers the growth of abalone market. Moreover, more strategies are needed to encourage and distribute home cooking of abalone rather than eating-out at restaurants. Last but not least, distribution system should be improved for better delivery of live abalone.

An Experimental Study on the Effect of Air Space on the Absorption Property of Composite Absorption System (배후공기층이 복합흡음구조의 흡음특성에 미치는 영향에 관한 실험적 연구)

  • Oh, Yang-Ki
    • KIEAE Journal
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    • v.1 no.2
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    • pp.47-54
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    • 2001
  • Single sound absorbers such as porous materials, panels, and Helmholts resonators have limited performance with some extents of frequency region. For example, porous materials do not attenuate low frequency sounds, while panels do not absorb high frequency sounds. Composite absorption structure with coverings, porous materials, and air gaps are an alternative for wide band sound absorption. Slits, panels, perforated panels are those materials for coverings, glass wool, mineral wool, polyester, and polyurethane are frequently used porous materials. Air gap between the porous material and background surface is one of major factors which governs the absorption characteristics of composite absorption structures, especially in the low frequency area. Calculations and measurements show that the absorption coefficients of composite absorption structure, in mid and low frequency bands, are getting higher with increased air gaps. Perforated panels rather than slits and panels are good coverings with higher number as far as absorption coefficient is concerned. Perforated panels with porous materials and 37 cm of air gaps in background have high absorption coefficients for all frequency bands, above 0.7 to 1.0. All measurements are performed in reverberation chamber, Mokpo National University, according to ISO 354 and ISO 3382.

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The effects of young consumers' perceptions of environment-friendly shopping bags and environmental consciousness on attitudes and purchase intentions

  • Smith, Madalyn;Cho, Eunjoo;Smith, Kathleen R.
    • The Research Journal of the Costume Culture
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    • v.24 no.5
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    • pp.687-696
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    • 2016
  • As consumers' interest in social responsibility (SR) has greatly increased in the last two decades, a growing body of academic research has examined the influence of consumers' environmental consciousness on their attitudes and purchase intentions toward environment-friendly apparel products. Use of environment-friendly shopping bags (EFSB; recycled and reusable bags) is an example of how apparel retailers engage in SR. However, little research has examined consumers' perceptions and their responses to the use of EFSB. To fill this research gap, this study examined the impact of young consumers' perceptions of EFSB and environmental consciousness on their attitudes and purchase intentions toward apparel retailers using EFSB. An online survey was conducted for data collection. A convenience sample of 212 college students was obtained from a large mid-Southern university in the U.S. A simple linear regression analysis was conducted to test all hypotheses. Results showed that young consumers' perceptions of EFSB positively influenced their environmental consciousness and their attitudes toward apparel retailers that use EFSB, which led to purchase intentions toward the retailers. Findings confirmed that young consumers placed a great degree of importance on EFSB and, therefore, would purchase apparel from retailers that use recycled or reusable shopping bags. These findings imply that providing EFSB is important in enhancing positive attitudes and purchase intentions toward apparel retailers.

Stability of the axially compliant fixed scroll in scroll compressors (스크롤 압축기에서 축방향 순응하는 고정부재의 안정성)

  • Kim, H.J.;Lee, W.H.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.9 no.2
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    • pp.93-103
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    • 1997
  • This study presents a way of improving the stability of fixed scroll in scroll compressors. For the scroll compressor whose fixed scroll is designed to move in the axial direction for the axial compliance, the fixed scroll is under the influence of the overturning moment produced by internal gas forces. Unless the overturning moment is properly compensated by the moments of reaction forces at the suspension of the fixed scroll to the compressor frame, the fixed scroll would exhibit wobbling motion, increasing gas leakage through the gap induced by the wobbling of the fixed scroll between the two scroll members. The conditions on which the wobbling motion can be suppressed have been found analytically; The axial position of the fixed scroll suspension should be made within a certain range. The upper limit of this range is the axial location for the o-rings which are inserted between the fixed scroll and the back pressure chamber to promote sealing for the gas in the back pressure chamber. And the lower limit is mainly determined by the magnitude of the axial sealing force. As long as the axial sealing force is not negative over all crank angles, the lower limit is not above the mid-height of the scroll wrap. Larger axial sealing force lower the lower limit.

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Status of Domestic Byproduct Hydrogen and Infrastructure (국내 부생수소 현황과 수소 유통 인프라)

  • Sim, Kyu-Sung;Kim, Jong-Won;Kim, Jung-Duk;Hwang, Gap-Jin;Kim, Heung-Sun
    • Transactions of the Korean hydrogen and new energy society
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    • v.13 no.4
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    • pp.330-338
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    • 2002
  • A long-term energy system in the future is expected to be based on the ideal circulation system between water and hydrogen in the sense that the hydrogen prepared from water eventually returns to water again after its use. Currently, with respect to the hydrogen energy system, it is predicted that the turning-point at which the production cost of hydrogen will become to be lower than that of fossil fuels would be after 2010. However, fuel cell technology would be able to be practically used for the applications to the transportation vehicles and small-scale power sources from 2004, and therefore, an efficient construction of the infrastructure covering hydrogen production and supply systems would be required with short-/mid-term technologies for the $CO_2$ reduction associated with fossil fuel utilization. In this paper, the hydrogen quantity available in domestic market has been estimated focusing on the hydrogen by-produced from domestic industries, and also the infrastructure for hydrogen-driven vehicles like fuel cell cars has been reviewed.

Photofield-Effect in Amorphous InGaZnO TFTs

  • Fung, Tze-Ching;Chuang, Chiao-Shun;Mullins, Barry G.;Nomura, Kenji;Kamiya, Toshio;Shieh, Han-Ping David;Hosono, Hideo;Kanicki, Jerzy
    • 한국정보디스플레이학회:학술대회논문집
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    • 2008.10a
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    • pp.1208-1211
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    • 2008
  • We study the amorphous In-Ga-Zn-O thin-film transistors (TFTs) properties under monochromatic illumination ($\lambda=420nm$) with different intensity. TFT off-state drain current ($I_{DS_off}$) was found to increase with the light intensity while field effect mobility ($\mu_{eff}$) is almost unchanged; only small change was observed for sub-threshold swing (S). Due to photo-generated charge trapping, a negative threshold voltage ($V_{th}$) shift is also observed. The photofield-effect analysis suggests a highly efficient UV photocurrent conversion in a-IGZO TFT. Finally, a-IGZO mid-gap density-of-states (DOS) was extracted and is more than an order lower than reported value for a-Si:H, which can explain a good switching properties of the a-IGZO TFTs.

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Effect of Crossflow on Heat (Mass) Transfer of an Impingement/Effusion Cooling System (충돌제트/유출냉각기법에서 횡방향유동이 열/물질전달에 미치는 영향)

  • Nam, Yong-Woo;Choi, Jong-Hyun;Cho, Hyung-Hee;Cho, Hyung-Hee
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.2219-2226
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    • 2003
  • Two perforated plates are placed in parallel and staggered arrangements with a gap distance of 2 times of the hole diameter, and initial crossflow passes between the plates. Both the injection and effusion hole diameters are 10 mm, and the Reynolds number based on the hole diameter and hole-to-hole pitch are fixed to 10,000 and 6 times of the hole diameter, respectively. To investigate the effect of crossflow, the flow rate of crossflow is changed from 0.2 to 2 times of that of the impinging jet. A naphthalene sublimation method is used to determine the local heat/mass transfer coefficients on the upward facing surface of the effusion plate. With the initial crossflow, the heat/mass transfer rates on the effusion (target) plate decrease as the velocity of crossflow increases, since the crossflow induces the locally low transfer regions formed at the mid-way between the effusion holes. However, the impingement/effusion cooling with crossflow presents higher heat/mass transfer rates than the array jet impingement cooling with the same initial crossflow.

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The development of piezoelectric smart panels for wide range transmission noise reduction (광대역 전달 소음저감을 위한 지능패널의 개발)

  • Lee, Joong-Kuen;Kim, Jae-Hwan;Cheong, Chae-Cheon;Kang, Young-Kyu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.06a
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    • pp.1273-1279
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    • 2000
  • A new concept of piezoelectric smart panels for noise reduction in wide band frequencies is proposed and their possibility is experimentally investigated. The proposed panels are based on active and passive methods. They use piezoelectric smart structure technology for active noise reduction at low band frequencies and passive sound absorbing materials for mid-range of noise frequencies. To prove the concept of piezoelectric smart panels, an acoustic measurement experiment was performed. The smart panels exhibit a good noise reduction in middle and high frequency ranges due to the mass effects of absorbing materials or/and the air gap. The use of piezoelectric smart panel renders noise reduction large at resonance frequency. Another concept of smart panel that uses piezoelectric damping is experimentally investigated. Since piezoelectric dampings can reduce vibration and noise at resonance frequencies with simple shunt circuit, they have merits in terms of economy and simplicity. Dissipated energy method(DEM) is adopted to tune the shunt circuit precisely in piezoelectric dampings. Noise reduction at multiple resonance frequencies is demonstrated.

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A MEASUREMENT OF DISPLACEMENTS OF CAST FRAMEWORK BY TORCH SOLDERING AND ELECTRIC SOLDERING TECHNIQUES (화염 납착법과 전기 납착법에 의한 금합금 주조체의 변위 양상에 관한 계측학적 연구)

  • Jeon, Sang-Won;Lim, Jang-Seop;Jeong, Chang-Mo;Jeon, Young-Chan
    • The Journal of Korean Academy of Prosthodontics
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    • v.37 no.6
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    • pp.791-799
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    • 1999
  • The purpose of this study was to investigate the displacements of cast framework by torch soldering and electric soldering techniques. Specimen had two cylinders and connecting bar that had sectioned with 0.3mm gap at mid point. 10 of total specimens were divided into two groups. In torch soldered group, soldering investment block was made and conventional torch solder-ing procedure was carried out. In electric soldered group, electric soldering was carried out on the master cast without soldering investment block by using electric soldering machine(Dentapunkt DP 7, Kulzer, Germany) After soldering procedure, three dimensional coordinates of two centroids of each cylinder were measured by three dimensional coordinate measuring machine. The intercentroidal displacement and global displacement were calculated and then, these values were compared and evaluated. The results were obtained as follows: 1. Intercentroidal distances of specimens decreased after both soldering procedures, and the decrease in intercentroidal distance was greater for torch soldered group than for electric soldered group 2. Global displacements of torch soldered group were greater than those of electric soldered group.

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The Characteristics of the Popular Culture Contemporary Fashion Shows -Focus on Pret-a-Porter Collections after the Mid of 1990s- (현대패션쇼의 대중문화적 특성(제2보) -1990년대 중반이후 기성복컬렉션을 중심으로-)

  • 장안화;박민여
    • Journal of the Korean Society of Costume
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    • v.54 no.5
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    • pp.1-12
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    • 2004
  • This Study has examined characteristics of the popular culture of the contemporary fashion show by each element as follows The fashion show place expanded its area when It moved its center because of not only the use of ordinary and public friendly place but also adjacent places post-modernism thought. The installation stage was produced by organic combination with the stage using object: The technology for the stage has produced dynamic variability and variety enough to expand the stage. The dramatic element of production technique was introduced to the fashion show to shorten gap with ordinary life and transfer a theme by facial expressions, gesture and pose. etc of a model In addition. its performance element combines other genre freely to be one time and viewers' participating type technique. At the minimalism element, clothing functions moderately as main factor of the fashion show: Technical elements are added to emphasize future Images. At sound tracks and sound effects, the show's overall atmosphere has been revived to remake various genre of music and improve images. At the fashion model, objective appearance boundary is collapsed to expand model concept and make tools of their own. The fashion show has external values of active movement of associated industry as well as economic boost enough to produce jobs, and internal values to provide aesthetic rest and satisfactions to let the ones. who are isolated from recreation values and the society, establish friendly relations with the society