• Title/Summary/Keyword: solidity

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A Study on the Effects f Vacuum Degree on the Plastic Parts (진공도가 성형제품에 미치는 영향에 관한 연구)

  • 신남호
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1999.10a
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    • pp.293-298
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    • 1999
  • To make use of various switches, relays, and control instruments, a connector (jack) is used to link the battery (power) and operating units. A connector must have precision as well as solidity to control the power in a car. To improve productivity, we researched and developed a connector molding by adapting vacuum system and we've made it possible to minimize the incomplete molding and weld-line. As a result, good quality can be warranted with less costs.

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Analysis of impeller exit condition using a modified Stanitz equation in a centrifugal refrigerant compressor (예측수정된 Stanitz 방정식을 이용한 임펠러 출구 조건 해석)

  • Jeong, J.;Kim, C.D.;Lee, H.K.;Lee, Y.D.
    • 유체기계공업학회:학술대회논문집
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    • 1999.12a
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    • pp.61-68
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    • 1999
  • We have measured pressure distributions within the diffuser and pressures at the inlet and outlet of the compressor in orde to match impeller and low-solidity diffuser of 500RT centrifugal refrigerant-compressor which has been developed in LG Cable Ltd. Modified Stanitz equation is used to predict the measured data by tuning several parameters and then is validated. Using the validated parameters and modified Stanitz equation, we have obtained data necessary to design the diffuser.

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A Study on Trailing Edge Noise from a Blade Cascade in a Uniform Flow (케스케이드 날개 후단소음 특성에 관한 연구)

  • J. M. Son;Kim, H. K.;Lee, S.
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2002.11a
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    • pp.366.1-366
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    • 2002
  • It is addressed that the turbulent broadband sound power from a sirocco fan can be modeled by the trailing edge noise. The trailing edge noise is usually influenced by inflow turbulence, separation, and boundary layer on the blade. The design parameters such as solidity(c/s) and stagger angle are specified to predict performance and noise level because the separation and slip velocity are strong1y affected by them along with the flow coefficient. (omitted)

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An Online Voting System based on Ethereum Block-Chain for Enhancing Reliability (신뢰성 향상을 위한 이더리움 블록체인 기반의 온라인 투표 시스템)

  • Kim, Chul-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.4
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    • pp.563-570
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    • 2018
  • Existing online voting is not being used for public elections due to uncertainty about security threats, and offline voting costs a lot of money. As an alternative, blockchain is emerging. Applying blockchain technology to online voting will ensure transparency and confidentiality, because voter information and aggregate information are distributed and managed. Since a blockchain distributes the voting information, it will be more secure than existing central server - based online voting systems. If blockchain technology is applied to public elections, and the transparency and confidentiality of the voting information is guaranteed, the cost of voting will be greatly reduced. This paper tries to apply to an online voting system the Ethereum platform from among the blockchain technologies. Ethereum is a highly scalable blockchain technology that provides a smart contract based on the Solidity language to develop an online voting contract and to distribute the contract to each voter. Each voter votes on the contract that has been distributed, and the votes are distributed to other voters. The experiment verifies the consistency of the stored voting information.

Grouting Performance for the Reinforcement of Operating Railway Roadbed (운영 중인 철도노반 보강을 위한 그라우팅 성능)

  • Jung, Hyuk Sang;Han, Jin Kyu;Moon, Joon Shik;Yoon, Hwan Hee
    • Journal of the Korean GEO-environmental Society
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    • v.18 no.12
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    • pp.13-23
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    • 2017
  • This paper discusses about the reinforcement materials and construction method in order to cope with roadbed settlement in operating railway. In Korea, concrete tracks have been introduced to urban railways, high-speed railways, and general railways, but some recently constructed concrete tracks have experienced roadbed settlements. Reinforcement of the railway roadbed is urgent task for safe operation of railway, but it is difficult to reinforce the roadbed and there are no case history of reinforcing railway roadbed under an operating railroad track. Therefore, in this study, the target performance level for roadbed reinforcement was determined, and infiltration and solidity injection efficiency were investigated for selected reinforcement materials. As a result of the study, it was found that the generally used reinforcement materials and methods for geotechnical works need to be improved for applying in railway roadbed reinforcement.

Extremozymes: A Potential Source for Industrial Applications

  • Dumorne, Kelly;Cordova, David Camacho;Astorga-Elo, Marcia;Renganathan, Prabhaharan
    • Journal of Microbiology and Biotechnology
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    • v.27 no.4
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    • pp.649-659
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    • 2017
  • Extremophilic microorganisms have established a diversity of molecular strategies in order to survive in extreme conditions. Biocatalysts isolated by these organisms are termed extremozymes, and possess extraordinary properties of salt allowance, thermostability, and cold adaptivity. Extremozymes are very resistant to extreme conditions owing to their great solidity, and they pose new opportunities for biocatalysis and biotransformations, as well as for the development of the economy and new line of research, through their application. Thermophilic proteins, piezophilic proteins, acidophilic proteins, and halophilic proteins have been studied during the last few years. Amylases, proteases, lipases, pullulanases, cellulases, chitinases, xylanases, pectinases, isomerases, esterases, and dehydrogenases have great potential application for biotechnology, such as in agricultural, chemical, biomedical, and biotechnological processes. The study of extremozymes and their main applications have emerged during recent years.

Analysis of Resistance Distribution of the Midwater Trawl Net (중층 트롤 그물의 저항 분포 해석)

  • 박진영
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.35 no.3
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    • pp.250-265
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    • 1999
  • Quality and distribution of the TEA(Total Enclosed Area), TSA(Twine Surface Area), solidity ratio and resistance according to the partial nets of the midwater trawl net were examined through experiment at the sea to standardize a design of the midwater trawl net.The results can be summarized as follows;1. The TEA, TSA and resistance of the trawl net were increased definitely according to increasing the scale of the trawl net, and this is the most important factor to design the trawl net.2. As the result of analysis of the distributions of the bag net was smaller than the others. Because TEA for rear end of the wing net is decreased suddenly, we can judge that the trawl net was towed irregularly. 3. The resistance distribution of the partial net was increased suddenly from central part of the bag net and was showed large value in the codend.4. The resistance of the net from the position one of three to gab net and codened charged 75% at all resistance of net.

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Trailing Edge Noise Modification in a Blade Cascade (익렬 날개 후단소음의 저감)

  • Son, J.-M.;Kim, H.-J.;Lee, S.;Cho, S.-M.
    • 유체기계공업학회:학술대회논문집
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    • 2002.12a
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    • pp.116-122
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    • 2002
  • It is addressed that the turbulent broadband sound power from a sirocco fan can be modeled by the trailing edge noise. The trailing edge noise is usually influenced by inflow turbulenca separation, and boundary layer thickness on the blade. The design parameters such as solidity (c/s) and stagger angle are specified to predict performance and noise level because the separation and slip velocity are strongly affected by them along with the flow coefficient. This paper reports the effects of the stagger angle upon the trailing edge noise for various trailing edge shapes. It is believed that the serrated trailing edge provides break-up mechanism for organized convecting vortices, thereby reduce the overall noise level for every case of stagger angle.

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On the Analysis of Vertical-axis Wind Rotor (수직축 풍력발전기의 해석에 관하여)

  • ;;Lee, Chung-Oh
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.3 no.2
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    • pp.60-67
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    • 1979
  • Aerodynamic forces acting on a curved blade are computed theoretically taking into account the variation of wind speed over the blade to investigate the performance of a vertical axis wind rotor. It is shown that the rotor does not self start at the rated wind speed without a supplementary starting device and that most of the power output is contributed by the central portion of the rotor, and the use of spoilers for limiting the maximum rotational speed is needed for safety. It is also shown that provision of skew angle to the blade does not improve the starting characterstics and only reduces the maximum power output. The effects of geometric variables such as skew angle, blade solidity and ratio of the rotor height to diameter are also discussed.