• Title, Summary, Keyword: Fur quality

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Calculation of Equivalent Feeder Geometries for CANDU Transient Simulations

  • Cho, Seungyon;Muzumdar, Ajit
    • Proceedings of the Korean Nuclear Society Conference
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    • pp.429-436
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    • 1995
  • This paper describes a methodology for determination of representative CANDU feeder geometry and the pressure drops between inlet/outlet header and fuel channel in the primary loop. A code, MEDOC, was developed based on this methodology and helps perform a calculation of equivalent feeder geometry for a selected channel group on the basis of feeder geometry data (fluid volume, mass flow rate, loss factor) and given property data pressure, quality, density) at inlet/outlet header. The equivalent feeder geometry calculated based on this methodology will be useful fur the transient thermohydraulic analysis of the primary heat transport system for the CANDU heavy water-cooled pressure tube reactor.

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Effect of Drawing Parameters on the evenness of C/P Blended Rovings

  • Kim Gyu-Ho;Lee Dae-Hun;Ju Chang-Hwan
    • Proceedings of the Korean Fiber Society Conference
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    • pp.398-401
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    • 1998
  • The evenness of roving is greatly important fur the improvement of quality in final yarns. In order to produce even rovings, all fibers would have to be uniformly distributed over the whole rovings. However, that is ruled out by the inhomogeneity of fiber materials aid by the mechanical constraint. Accordingly, there are limits to the achievable fiber assembly evenness. Also, since the evenness of roving has greatly influenced on the evenness of slivers in drawing process, the optimum condition of drawing process is very important. (omitted)

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Internet-based Apparel Fabric Information System (인터넷을 기반으로 하는 의류용 소재 정보시스템)

  • 박창규;이대훈;이웅의
    • Journal of the Korean Society of Clothing and Textiles
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    • v.27 no.3_4
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    • pp.354-363
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    • 2003
  • In this research, an internet-based fabric information system has been developed. Recently, the numbers of textile industries which have their own homepages to advertise their product fabrics fur apparel through the Internet and textile e-Commerce web sites rapidly increase. Unfortunately, traditional fabric information systems based on direct meeting and trust cannot give sufficient information to numerous visitors of the Internet sites including fabric buyers for apparel. They can just view 3-dimensional fabric images and text-based specifications such as fabric density, composition, colors, weight, etc. To solve these problems, the new fabric information system fur apparel has been developed. The web-based fabric information system is composed of the following six modules; $\circled1$ fabric database management system, $\circled2$ a 3-D fabric drape image viewer to illustrate fabric appearances, $\circled3$ a virtual wearing system to apply a fabric to garment designs, $\circled4$ a fabric property viewer to confirm fabric characteristics, $\circled5$ a QC (quality control) document generator to manufacture high qualify garments with a fabric, and$\circled6$actual display mall to view actual fabrics. The fabric information system is simply performed by visitors clicking the buttons hyper-linked with JAVA applets on web browser. The web-based fabric information system enables the web site visitors to understand fabrics shown on the Internet in more details.

Parameter Design and Analysis for Aluminum Resistance Spot Welding

  • Cho, Yong-Joon;Li, Wei;Hu, S. Jack
    • Journal of Welding and Joining
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    • v.20 no.2
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    • pp.102-108
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    • 2002
  • Resistance spot welding of aluminum alloys is based upon Joule heating of the components by passing a large current in a short duration. Since aluminum alloys have the potential to replace steels fur automobile body assemblies, it is important to study the process robustness of aluminum spot welding process. In order to evaluate the effects of process parameters on the weld quality, major process variables and abnormal process conditions were selected and analyzed. A newly developed two-stage, sliding-level experiment was adopted fur effective parameter design and analysis. Suitable ranges of welding current and button diameters were obtained through the experiment. The effects of the factors and their levels on the variation of acceptable welding current were considered in terms of main effects. From the results, it is concluded that any abnormal process condition decreases the suitable current range in the weld lobe curve. Pareto analysis of variance was also introduced to estimate the significant factors on the signal-to-noise (S/N) ratio. Among the six factors studied, fit-up condition is found to be the most significant factor influencing the SM ratio. Using a Pareto diagram, the optimal condition is determined and the SM ratio is significantly improved using the optimal condition.

Accuracy Improvement in Transfer-Type Variable Lamination Manufacturing Process using Expandable Polystyrene Foam and Experimental Verification (단속형 가변 적층 쾌속 초형 공정(VLM-ST)을 위한 정밀도 향상에 관한 연구 및 실험적 검증)

  • Choe, Hong-Seok;An, Dong-Gyu;Lee, Sang-Ho;Yang, Dong-Yeol
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.7
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    • pp.97-105
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    • 2002
  • The use of rapid prototyping (RP) has reduced time to market, cut total costs and improved product quality by giving design and manufacturing teams the opportunity to verify and fine tune designs before committing them to expensive tooling and fabrication. In order to improve their unique characteristics according to the working principles, Variable Lamination Manufacturing process (VLM-ST) and corresponding CAD/CAM software (VLM-Slicer) is developed. The objective of this study is to improve the accuracy of VLM-ST process, and it can be done by offset fur cutting error correction, cutting path overrun fur sharp edge and reference shape generation for off-line stacking. It has been shown that, through the verification experiments for given practical shapes, the proposed algorithms are effective for diverse categories of three-dimensional shapes.

Services of Algae to the Environment

  • Rai, Lal-Chand;Har Darshan Kumar;Frieder Helmut Mohn;Carl Johannas Soeder
    • Journal of Microbiology and Biotechnology
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    • v.10 no.2
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    • pp.119-136
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    • 2000
  • Being autotrophic, algae occupy a trategic place in the biosphere. They produce oxygen both directly and indirectly through the chloroplasts of all green plants. The chloroplasts are believed to have originated from archaic prokaryotic algae through endosymbiosis with primitive eukaryotic cells. Phytoplankton and other algae regulate the global environment not only by releasing oxygen but also by fixing carbon dioxide. They affect water quality, help in the treatment of sewage, and produce biomass. They can be used to produce hydrogen which is a clean fuel, and biodiesel, and fix $N_2$ for use as a biofertilizer. Some other services of algae to the environment include restoration of metal damaged ecosystems, reducing the atmospheric $CO_2$ load and citigating global warming, reclamation of saline-alkaline unfertile lands, and production of dimethyl sulphide (DMS) and oxides of nitrogen (NOx) involved in the regulation of UV radiation. ozone concentration, and global warming. Algae can be valuable in understanding and resolving certain environmental issues.

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Development of Dry Films of Lead-free Transparent Dielectrics for PDP (PDP용 무연 투명유전체의 Dry Film 개발)

  • Lee Ji-Hun;Bang Jae-Cheol
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.6 no.6
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    • pp.497-501
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    • 2005
  • Dry film method was applied to fabricate lead-free transparent dielectric fur PDP(Plasma Display Panel). From various slurry compositions, it was able to find out the. best composition for producing high density green sheet. The slurry exhibited shear thinning characteristics which are known to be suitable fur producing a high quality green sheet. The thermal expansion coefficient of the fabricated transparent dielectric was measured to be $97{\times}10^{-7}/^{\circ}C$ which is close to the value of the glass substrate(PD-200). Cross sectional SEM of the transparent dielectric layer on PD-200 showed that the two layers were well attached each other with no observable gaps between them.

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An Experimental Study on Pressure drop Characteristics in Plate and Shell Heat Exchanger (Plate and Shell 열교환기내의 R-22 응축압력강하 특성에 관한 실험적 연구)

  • 이기백;서무교;박재홍;김영수
    • Journal of the Korean Society of Marine Engineering
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    • v.25 no.6
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    • pp.1220-1227
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    • 2001
  • The condensation pressure drop fur refrigerant R-22 flowing in the plate and shell heat exchanger were investigated experimentally in this study. Two vertical counterflow channels were formed in the exchanger by three plates of commercial geometry with a corrugated trapezoid shape of a chevron angel of $45^{\circ}$. The condensing R-22 flowing down in one channel exchanges heat with the cold water flowing up in the other channel. The effects of the mean vapor quality, mass flux, average imposed heat flux and system pressure of R-22 on the pressure drop were explored in detail. The quality change of R-22 between the inlet and outlet of the refrigerant channel ranges from 0.03 to 0.05. The present data showed that pressure drop increases with the vapor quality. At a higher mass flux, pressure drop is higher for the entire range of the vapor quality. Also, a rise in the average imposed heat flux causes an slight increase in the Pressure drop. Finally, at a higher system pressure the pressure drop is found to be slightly lower. Correlation is also provided for the measured pressure drops in terms of the friction factor.

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The Effect of Cognitive Gap on the Hotel Restaurant Performance (호텔.레스토랑의 서비스품질 인식 차이(Gap)와 경영성과 간의 상관성)

  • 나영선;박기안;이훈영
    • Culinary science and hospitality research
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    • v.8 no.2
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    • pp.37-58
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    • 2002
  • Up to these days, hotels are assumed to compete each other. Due to the spread of high quality the hotel restaurants have begun to face an intensive competition. Hotel food at Beverage have become the more competitive along with fund, good price, service, quality food, and management know-how. It causes the hotel restaurants confront with management difficulties. In order to overcome the management difficulties, hotel restaurants have to improve their marketing abilities and especially to improve their service quality. For this, it is necessary fur hotel restaurants to investigate how their service providers and receivers recognize their service quality. In this research, we examined the cognitive three types of cognitive gaps among customers, service providers, and managers both on the service quality and on the positioning of hotel restaurants. Their cognitive gaps proved negatively correlated with hotel's performance. This research suggests the following findings. Firstly, the competitiveness of hotel restaurant depends on the accurate communication and consensus among managers, service providers, and customers. Secondly, using the information about cognitive gaps recognized, each hotel restaurant should develop concrete marketing plans and strategies with a careful consideration about its current competitive position and management condition.

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A Method for Improving Anchor Picture Quality of Multiview Video Coding Scheme (다시점 비디오 부호화의 기준 영상 화질 향상 방법)

  • Park, Min-Woo;Park, Jong-Tae;Park, Gwang-Hoon
    • Journal of Broadcast Engineering
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    • v.13 no.3
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    • pp.388-400
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    • 2008
  • This paper introduces a cost-effective method fur improving anchor picture quality of a multiview video coding scheme that is mainly based on chroma compensation. Proposed method is applied to both INTER $16{\times}16$ and SKIP modes in only anchor P-pictures. By testing using JVT common test conditions, simulation results show that proposed method can obtain the average BD-PSNR gains fur U and V as 0.136 dB and 0.127 dB, respectively, while maintaining almost same performance for Y (luminance). For the range of low bit-rates, it is observed that average BD-PSNR gains of Y, U, and V are 0.141 dB, 0.494 dB and 0.525 dB, respectively. Necessary computational complexity is very marginal because the number of anchor P-pictures is only 4.18% in comparison with whole coded sequences, however it can be found that the proposed method can significantly improve the coding efficiencies of color components.