• Title/Summary/Keyword: simplex

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The Phenomena of Injection Instability for Simplex Swirl Injector (Simplex Swirl Injector의 Injection Instability에 관한 연구)

  • Park, Byung-Sung;Kim, Ho-Young;Chun, Chul-Kyeun
    • 한국연소학회:학술대회논문집
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    • 2005.10a
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    • pp.287-293
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    • 2005
  • Most of all combustion system has combustion instability. It is a serious problem in combustion system. Unstable injection is one of the source of combustion instability. The experimental investigation of spray characteristics for simplex swirl injector were conducted experimentally. Two kerosene based fuels were chosen as the atomizing fluid. As the major operating parameters, fuel temperature and injection pressure were chosen, and varied in the range from 253 K to 293 K and from 0.2 MPa to 1.0 MPa, respectively. Direct spray images and mean diameter were measured for the various combination of operating parameters in the flow field. The results of present study show that the injection pressure and spray cone angle are fluctuated at specific conditions while it is continuous steady injection. As the fuel temperature changes continuously, spray cone angle varies discontinuously through the region of injection instability.

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Development Changes of Cambial Initials and Their Derivative Cells in the Trunk of Diospyros kaki THUNB. and Firmiana simplex W.F. WIGHT in Relation to Girth Increase (감나무와 벽오동 수간의 둘레증가에 따른 형성층 원시세포와 그 유도세포의 발생학적 변화)

  • 한경식
    • Journal of Plant Biology
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    • v.34 no.3
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    • pp.191-199
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    • 1991
  • This study has been conducted to investigate the developmental changes of cambial initials and their derivatives in relation to the growing girth of tree in Diosypros kaki and Firmiana simplex. In D. Kaki and F. simplex with typical storeyed cambium, increase in the girth of camium occurred by radial anticlinal division in general, however occasionally the increase was companied by pseudotransverse division. The length of fusiform initials, vessel member, and sieve tube member remained relatively constant throughout the secondary growth but that of fiber showed general tendancy to increase with growing girth of tree. During the girth increase of tree, height and number of ray remained constant in D. kaki, however in F. simplex, height of ray markedly decreased while the number of ray per unit area more or less increased. The secondary ray was originated from the segmentation or division of the side or end of fusiform initials.

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Electron Microscopic Observations on BHK-21 Cells Infected with Herpes Simplex Type 2 Virus (Herpes Simplex 2형 바이러스의 BHK-21 세포내에서의 전자현미경적 관찰)

  • Ko, Kwang-Kjune;Lee, Yun-Tai;Lee, Chong-Hoon
    • The Journal of the Korean Society for Microbiology
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    • v.16 no.1
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    • pp.71-82
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    • 1981
  • An electron microscopic study was carried out on the morphogenesis of herpes simplex type 2 virus in BHK-21 cells BHK-21 cells was found susceptible to infection and replication of herpes simplex type 2 virus cytopathic effects of the herpes type appeared at approximately 1 day postinoculation. Foci consisting of rounded refractile cells and syncytia were observed. Projection of the nuclear membrane in the infected cells was also seen, Several infected cells showed a track-shaped structure which apparently consisted of multiple layered membranes of the nucleus.

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A study on constructing a good initial basis in the simplex method (단체법에서의 초기기저 구성에 관한 연구)

  • 서용원;김우제;박순달
    • Korean Management Science Review
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    • v.13 no.3
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    • pp.105-113
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    • 1996
  • Constructing an initial basis is an important process in the simplex method. An initial basis greatly affects the number of iterations of iterations and the execution time in the simplex method. The purpose of this paper is to construct a good initial basis. First, to avoid linear dependency among the chosen columns, an enhanced Gaussian elimination method and a method using non-duplicated nonzero elements are developed. Second, for an order to choose variables, the sparsity of the column is used. Experimenal results show that the proposed method can reduce the number of iterations and the execution time compared with Bixby's method by 12%.

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Metazoan Parasites Observed in Darkblotched Rockfish, Sebastes crameri (Jordan) in Newport Fish Market

  • Chun, Kae-Shik
    • Korean Journal of Environmental Biology
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    • v.20 no.4
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    • pp.309-311
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    • 2002
  • A total of ten specimens of darkblotched rockfish, Sebastes crameri obtain-ed from Newport fish market were examined for parasites during February, 2002. Eight out of ten S. crameri were found to be infected with metazoan parasites. They were flatworm Trochopus australis, nematoda Anisakis simplex, and copepods Neobrachiella robusta and Chondracanthus triventricosus. Nine (30.0%) T. australis, seven (30.0%) N. robusta, one (10.0%) C. triventricosus and seven (60.0%) A. simplex were infected. Among them, A. simplex was the most abundant and prevalent metazoan parasites in S. crameri. T. australis and N. robsta were found in gills with moderate intensity (1.7 and 1.9, respectively), and C. triventricosus in dorsal fin with low intensity (0.3).

Primal-Interior Dual-Simplex Method and Dual-Interior Primal-Simplex Method In the General bounded Linear Programming (일반한계 선형계획법에서의 원내부점-쌍대단체법과 쌍대내부점-원단체법)

  • 임성묵;김우제;박순달
    • Journal of the Korean Operations Research and Management Science Society
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    • v.24 no.1
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    • pp.27-38
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    • 1999
  • In this paper, Primal-Interior Dual-Simplex method(PIDS) and Dual-Interior Primal-Simplex method(DIPS) are developed for the general bounded linear programming. Two methods were implemented and compared with other pricing techniques for the Netlib. linear programming problems. For the PIDS, it shows superior performance to both most nagative rule and dual steepest-edge method since it practically reduces degenerate iterations and has property to reduce the problem. For the DIPS, pt requires less iterations and computational time than least reduced cost method. but it shows inferior performance to the dynamic primal steepest-edge method.

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Comparison between Genetic Algorithm and Simplex Method in the Evaluation of Minimum Zone for Flatness (평면도의 최소 영역 평가에서 유전자 알고리듬과 심플렉스 방법의 비교)

  • Hyun, Chang-Hun;Shin, Snag-Choel
    • Journal of Industrial Technology
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    • v.20 no.B
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    • pp.27-34
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    • 2000
  • The definition of flatness is given by ISO, ANSI, KS, etc. but those standards don't mention about the specific methods for the flatness. So various solution models that are based on the Minimum Zone Method have been proposed as an optimization problem for the minimax curve fitting. But it has been rare to compare some optimization algorithms to make a guideline for choosing better algorithms in this field. Hence this paper examined and compared Genetic Algorithm and Simplex Method to the evaluation of flatness. As a result, Genetic Algorithm gave the better or equal flatness than Simplex Method but it has the inefficiency caused from the large number of iteration. Therefore, in the future, another researches about alternative algorithms including Hybrid Genetic Algorithm should be achieved to improve the efficiency of Genetic Algorithm for the evaluation of flatness.

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Optimization of Multimodal Function Using An Enhanced Genetic Algorithm and Simplex Method (향상된 유전알고리듬과 Simplex method을 이용한 다봉성 함수의 최적화)

  • Kim, Young-Chan;Yang, Bo-Suk
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2000.11a
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    • pp.587-592
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    • 2000
  • The optimization method based on an enhanced genetic algorithms is proposed for multimodal function optimization in this paper. This method is consisted of two main steps. The first step is global search step using the genetic algorithm(GA) and function assurance criterion(FAC). The belonging of an population to initial solution group is decided according to the FAC. The second step is to decide the similarity between individuals, and to research the optimum solutions by simplex method in reconstructive search space. Two numerical examples are also presented in this paper to comparing with conventional methods.

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Infection of Parasitic Anisakis Type Larvae (Nematoda) from Some Rockfishes, Sebastes spp. (볼락류 Sebastes spp.에 있어서 선충류 아니사키스 유충의 감염)

  • Chun, Kae-Shik
    • Journal of Food Hygiene and Safety
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    • v.17 no.4
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    • pp.206-209
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    • 2002
  • From February through March 2002, sixteen rockfishes representing three species were collected from Oregon Coast Aquarium and Newport fish market and examined far nematodes. During this study, a total of 157 Anisakis type larvae were recovered from Sebastes spp. and parasitized for an average infection prevalence of 50.0%. The yellowtail rockfish, S. flavidus, darkblotched rockfish, S. crameri, and canary rockfish, S. pinniger examined were infected with 110 Anisakis simplex larva, 30 Contracaecum spp. larva and 17 Pseudoterranova decipiens larva. Of the rockfishes examined, 75.0% carried Sebastes crameri, and 12.5% S. flavidus and S. crameri, respectively. The sites of infection far Anisakis type larvae were the intestine, omentum, and stomach walls. A. simplex larvae infected 60.0% on S. crameri and 33.3% on S.flavidus and S. pinniger respectively. The prevalence of Contracaecum sp. larvae and Pseudoterranova decipiens larvae on S. pinniger was 33.3%. The intensities of A. simplex larvae ranged from 1 to 87 in S. flavidus, S. crameri, and S. pinniger. The intensity of Contracaecum spp. larvae and P. decipiens larvae ranged from 0 to 30 in S. pinniger.