• Title/Summary/Keyword: fixing

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Issues and Solutions of Roe Schemes for High Mach Number Flows (고마하수 유동에서 Roe 해법의 문제와 해결)

  • Won S. H.;Choi J. Y.;Jeung I. S.
    • 한국전산유체공학회:학술대회논문집
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    • 2005.04a
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    • pp.128-134
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    • 2005
  • In the CFD area, the numerical analysis of high Mach number flow over a blunt-body poses many issues. Various numerical schemes have been developed to cover the issues, but the traditional schemes are still used widely due to the complexities of new schemes and intricacy of modifying the established codes. In the present study, the well-known Roe's FDS based on TVD-MUSCL scheme is used for the solution of very high Mach number three-dimensional flows posing carbuncle and non-physical phenomena in numerical analysis. A parametric study was carried out to account for the effects of the entropy fixing, grid configurations and initial condition. The carbuncle phenomena could be easily overcome by the entropy fixing, and the non-physical solution could be eliminated by the use of the modified initial condition regardless of entropy fixing and grid configurations.

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A Study on the One Bath One Step Thermosol Dyeing of Polyester/Cotton Blended Fabrics (폴리에스터/면 혼방직물의 1욕 1단 서모졸 염색에 관한 연구)

  • Ro, Duck-Kil
    • Textile Coloration and Finishing
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    • v.20 no.1
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    • pp.16-21
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    • 2008
  • In this study the effects of swelling and fixing agent for the cotton side of polyester/cotton blended fabrics and the thermosol temperature on the dyeing properties and fastness. were investigated, when the polyester/cotton blended fabrics were dyed with a disperse dye which was able to dye both side of fiber by one bath one step thermosol process. The obtained results are as follows; The dye adsorption decreased with the increase of cotton blend ratio in polyester/cotton blended fabrics, when the ratio of swelling and fixing agent for cotton side was constant. As the thermosol temperature increased up to $210^{\circ}C$, the dye adsorption were increased, but that effect was less significant when the cotton blend ratio was higher.

A Study on the Sericin Fixation of Raw Silk Fibers by Fixing with the Mixtures of Various Amines and Formalin (아민류와 포르말린 혼합액에 의한 실크 생사의 세리신 정착에 관한 연구)

  • Park, Geon-Yong
    • Textile Coloration and Finishing
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    • v.21 no.1
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    • pp.67-72
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    • 2009
  • To investigate the strong and effective sericin fixing agents and conditions, raw silk fibers were treated with the mixtures of urea-formalin, thiourea-formalin and melamine-formalin as sericin fixing agents, respectively. And the treated raw silk fibers were degummed by the degumming liquors of alkaline detergent and sodium carbonate to confirm the hardness of sericin fixation. The weight of raw silk fibers was decreased in the process of sericin fixation treating at 80$^{\circ}C$ for 60min. The effective sericin fixation was obtained by treating at $60{\sim}80^{\circ}C$ for 15min with the mixture of melamine and formalin. The mixture of melamine and formalin showed an outstanding ability of sericin fixation because the three amino groups of melamine were able to cross-link the hydroxy amino acids of sericin such as serine with the assistance of formalin.

A Basic Study on Position Fixing by Free Gyros (자유자이로를 이용한 위치결정에 관한 기초 연구)

  • Park, Sok-Chu;Jeong, Tae-Gweon
    • Journal of Navigation and Port Research
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    • v.28 no.8
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    • pp.653-657
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    • 2004
  • The authors aim to design further an upgraded and self-contained position fixing system to meet the future commercial requirements. As a first step this paper is to investigate the theoretical structure of position fixing based on the nature of free gyro, in which the tilt angles of the two spin axes at an arbitrary position are measured respectively and the elapsed time with respect to a reference position or starting point is observed And it illustrates some limitations to be expected in this system.

Mobile Crane Ground-Fixing System (이동식 크레인의 접지설계 시스템)

  • Ho, Jong-Kwan;Seo, Jong-Min;Kim, Sun-Kuk
    • KIEAE Journal
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    • v.7 no.6
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    • pp.83-90
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    • 2007
  • A mobile crane has been more frequently used to deal with the increased capital-intensive projects in line with the economic growth, but the operation is still heavily dependent on personal experience in the past, resulting in severe overturn accidents that cause the loss of lives and damage to the properties. A crane shall be installed in a systematic manner that proved to be safe in engineering aspect, and should the installation and operation be blindly dependent on experience alone, it would apparently cause a great risk. Particularly the mobile crane, among others, frequently causes a severe overturn accident due to poor ground-fixing device. The study therefore focused on fixing system of mobile crane and the outcome is highly expected to make a great commitment to selecting the optimal type of crane for the project as well as to securing the safety during construction.

Evaluation of Physical Properties of Mucosal Adhesive Tablets (I):-Adhesive Force- (점막 부착정제의 물성평가(I):-부착력-)

  • Park, Kwang-Sin;Chung, Bee-Hwan;Cha, Bong-Jin;Kwon, Jong-Won
    • Journal of Pharmaceutical Investigation
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    • v.23 no.1
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    • pp.51-53
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    • 1993
  • Mucoadhesive tablets containing hydroxypropylcellulose-H (HPC) and carbopol 934 (CP) were prepared from direct compression. Their adhesive forces and water absorptions were investigated by using mouse peritoneal membrane and 1.5% agar plate, respectively. Adhesive force was significantly improved with increasing CP concentration, but was not affected by compression force and addition of disintegrants. And adhesive force to mouse peritioneal membrane was increased as fixing time increased. In conclusion, adequate adhesive force can be obtained by control of CP/HPC ratio and fixing time.

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The Gyroscope Positioning and North Finding System (자이로스코프 위치시스템과 지북시스템)

  • Park, Sok-Chu
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2004.11a
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    • pp.291-294
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    • 2004
  • There are many position fixing systems in the world from ancient times. But the principles are to compare the position to want to know with the known position already. The position finding system which is not restricted by weather condition and/or electronic apparatus has been sought. The best system is the GPS as far. But the system has the fatal faults as follows; 1. to depend on satellite's accuracy, 2. not to use underwater. This paper is to investigate theoretically position fixing and north finding by using free gyroscope. This paper introduce a position fixing and north finding method by measuring inclination of 2 free gyroscopes. And this system does not depend on the weather condition and underwater condition. What is more, it could use on the planets, if the gravity exits.

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Systematic Review of Bug Report Processing Techniques to Improve Software Management Performance

  • Lee, Dong-Gun;Seo, Yeong-Seok
    • Journal of Information Processing Systems
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    • v.15 no.4
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    • pp.967-985
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    • 2019
  • Bug report processing is a key element of bug fixing in modern software maintenance. Bug reports are not processed immediately after submission and involve several processes such as bug report deduplication and bug report triage before bug fixing is initiated; however, this method of bug fixing is very inefficient because all these processes are performed manually. Software engineers have persistently highlighted the need to automate these processes, and as a result, many automation techniques have been proposed for bug report processing; however, the accuracy of the existing methods is not satisfactory. Therefore, this study focuses on surveying to improve the accuracy of existing techniques for bug report processing. Reviews of each method proposed in this study consist of a description, used techniques, experiments, and comparison results. The results of this study indicate that research in the field of bug deduplication still lacks and therefore requires numerous studies that integrate clustering and natural language processing. This study further indicates that although all studies in the field of triage are based on machine learning, results of studies on deep learning are still insufficient.

The Effect of Fixing Agents and Softner on Sericin Fixation of Trimethylolmelamine (트리메틸올멜라민의 세리신 정착에 있어 정착제와 유연제의 영향)

  • Park, Geon-Yong
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.5
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    • pp.93-98
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    • 2017
  • The fixing behaviors of raw silk yarns treated with melamine and formaldehyde at a molar ratio of 1:3 for trimethylolmelamine were investigated. Sericin was fixed during the fixing process, but a part of sericin I was removed simultaneously by hot water. The weight losses by fixing and the degumming losses by degumming greatly decreased with increasing concentrations of melamine and formaldehyde. The silk yarns fixed with 0.011 M melamine and 0.033M formaldehyde were significantly degummed due to the insufficient fixation of sericin and the alkaline hydrolysis of sericin by sodium carbonate during the degumming process. On the other hand, the silk yarns fixed with 0.055M melamine and 0.165M formaldehyde were degummed slightly (the degumming losses of 3-8%) due to the strong fixation of sericin, which might result from the many cross-linkages between the sericin I molecules, which were formed by trimethylolmelamine. Those fixed with the fixing solution containing 15% owf softener showed the lowest weight and degumming losses because under the condition of 15% owf softener, the cation of the softener can effectively form ionic bonds with the negatively charged side chain of aspartic acid in sericin. In addition, van der Waals' forces may be also formed between the hydrophobic tail of the softener and the hydrophobic region of sericin, which may help inhibit the removal of sericin I.

Effects of Rice Straw Application on the Biological Nitrogen Fixation of Paddy Fields. -I. Effects of Application Method of Rice Straw on the Nitrogen Fixing Activity (논 토양(土壤)의 생물적(生物的) 질소고정(窒素固定)에 미치는 볏짚 시용효과(施用効果) -I. 볏짚 시용방법(施用方法)이 질소고정활성(窒素固定活性)에 미치는 영향(影響))

  • Yoo, Ick-Dong;Matsuguchi, Tatsuhiko
    • Korean Journal of Soil Science and Fertilizer
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    • v.16 no.1
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    • pp.77-83
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    • 1983
  • Effects of rice straw application (particularly application method; surface placement and deep placement) on the biological nitrogen fixing activity of paddy fields and on the growth of rice plant have been investigated by the lysimeter experiment with Aragawa alluvial soil and Tochigi ando soil. 1. Nitrogen fixing activity of plow layer (0~1cm) was increased by the rice straw application, notably by the phototrophs, both deep placement and surface placement, between 1 and 2 months of initial growth stage of rice plant. 2. Surface placement method stimulated the nitrogen fixing activity more significantly them the deep placement method, and also showed good effects on the growth of rice plant. 3. The increased of effect on the nitrogen fixing activity of surface placed area was found to be originated from the applied rice straw and its neigh bouring area. 4. Nitrogen fixing activity of surface placed rice straw was rather promoted by the application of herbicides (2, 4, 6-arichlorophenyl ether) than the non-applicated plot.

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