• Title/Summary/Keyword: branching number

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Crystallization Characteristics of Metallocene Low Density Polyethylene (메탈로센 선형 저밀도 폴티에틸렌의 결정화 거동)

  • 김경룡;한정우;조봉규;강호종
    • Polymer(Korea)
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    • v.25 no.6
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    • pp.833-839
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    • 2001
  • The crystallization characteristics of metallocene linear low density polyethylene was investigated by small angle light scattering and comparison was made with Ziegler-Natta linear low density polyethylene. The special efforts were made to find out the effects of branching number, length of branching and co-monomer content of m-LLDPE on the crystallization behavior of m-LLDPE. It was found that m-LLDPE has longer induction time to start crystallization from the amorphous state than that of conventional LLDPE with similar branching number, but the rate of crystallization seems not change much in both LLDPEs. Lowering of branching number in m-LLDPE resulted in both increasing of rate of crystallization and reducing induction time to crystallize. In general, the maximum size of spherulites of m-LLDPE is bigger than that of conventional LLDPE.

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An anatomical study on the branching patterns of left coronary artery in the rats (흰쥐 왼쪽관상동맥의 분지 양상에 관한 해부학적 연구)

  • Ahn, Dong-Choon;Kim, In-Shik
    • Korean Journal of Veterinary Research
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    • v.47 no.1
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    • pp.7-17
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    • 2007
  • The left main descending artery (LMDA) of left coronary artery (LCA) in rats runs around the left side of conus arteriosus after arising from the aortic sinus and descends to the apex of heart with branching several branches into the wall of left ventricle (LV). The ligation site of LMDA for myocardial infarction (MI) is the 2~4 mm from LCA origin, between the pulmonary trunk and left auricle. The characteristics that rat heart has no interventricular groove on the surface and its coronary arteries run intramyocardially with branching several branches give the difficulty in surgery for MI which resulted in expected size. This study was aimed to elucidate the branching patterns of the left coronary artery for analysis of MI size and for giving the basic data to producing small MI intentionally in 2 male species that are widely used, Sprague-Dowley (SD) and Wistar-Kyoto (WKY), in the world. Red latex casting was followed by the microdissection in 27 and 28 hearts of SD and WKY male rats, respectively. The branching patterns of LMDA were classified into 3 major types and others based on the left ventricular branches (L). The Type I, Type II, Type III and others are shown in 55.6%, 22.2%, 14.8%, and 7.4% in SD, 60.7%, 10.7%, 7.1%, and 21.5% in WKY, respectively. The branching number of the first left ventricular branch (L1) that are distribute the upper one third of LV was 1.2~1.5, and its branching sites were ranging 0.9~2.1 ßÆ from LCA origin. L2, the second left ventricular branch distributing middle one third of LV, was the number of 1.2~1.4 and branching out ranging 5.1~5.7 mm. L3, the third left ventricular branch of LMDA distributing lower one third of LV, was the number of 1~1.5 and branching out ranging 7.0~9.3 mm from LCA origin. The common branch of L1 and L2 was branched from LMDA with the number of 1.1, and its site was located in the distance of mean of 1.5 mm and 2.8 mm in SD and WKY, respectively. The common branch of L2 and L3 was branched from LMDA with the number of 1, and its site was located in the distance of mean of 7.2 mm and 2.9 mm in SD and WKY, respectively. The right ventricular branches (R) of LMDA were short and branched in irregularly compared with L. The number of 1~4 of R were branched from LMDA. With regarding to the distribution area of L and the ligation site for MI, moderate MI (25~35% of LV) might be resulted in 70.4% and 60.7% in SD and WKY rats. Small MI might be produced intentionally if the ligation would be located at the 4~6 mm from LCA origin in the left side of LMDA. These data wold be helpful to expect the size of MI and to reproduce of small MI, intentionally, in rat hearts.

THE SOJOURN TIME AND RELATED CHARACTERISTICS OF THE AGE-DEPENDENT BRANCHING PROCESS

  • Kumar, B.-Krishba;Vijayakumar, A.
    • Journal of applied mathematics & informatics
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    • v.14 no.1_2
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    • pp.157-172
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    • 2004
  • An age-dependent branching process where disasters occur as a renewal process leading to annihilation or survival of all the cells, is considered. For such a process, the total mean sojourn time of all the cells in the system is analysed using the regeneration point technique. The mean number of cells which die in time t and its asymptotic behaviour are discussed. When the disasters arrival as a Poisson process and the lifetime of the cells follows exponential distribution, elegant inter- relationships are found among the means of (i) the total number of cells which die in time t (ii) the total sojourn time of all cells in the system upto time t and (iii) the number of living cells at time t. Some of the existing results are deduced as special cases for related processes.

Classification of plant type in Bupleurum falcatum L. by Multivariate Analysis (다변양(多變量) 해석법(解析法)에 의한 시호(柴胡)의 초형분류(草型分類))

  • Chung, Hae-Gon;Seong, Nak-Sol;Kim, Kwan-Su;Lee, Seong-Tak;Chae, Jae-Cheon
    • Korean Journal of Medicinal Crop Science
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    • v.2 no.2
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    • pp.140-145
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    • 1994
  • B. falcatum plants were classified into six groups from group I to grop VI by the complete linkage cluster method depending on 8 charactenstics such as plant height. number of nodes, number of branches, position of the first branching node root diameter, root length, number of lateral root, dry weight of root. These groups are divided into two plants types, such as multi-branching and non multi-branching type by the number of branches, group II and group VI were the multi-branching types and the other groups were nonmulti-branching ones, Dry weight of root had highly positive correlation with the number of branches and negative correlation with the position of first branching nodes.

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Studies on the Flowering and Maturity in Sesame (Sesamum indicum L.) II. Capsule-Setting Habit by Different Plant Types (참깨의 개화 등숙에 관한 연구 II. 참깨의 초형에 따른 착삭습성)

  • Jung-Il Lee;;Eung-Ryong Son
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.29 no.4
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    • pp.376-385
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    • 1984
  • The habit of anthesis and maturity of sesame were investigated as a basic research for the improvement of high-yielding varieties and cultural practices. Eight different plant types were identified using typical cultivars among gene pool grown in Korea. Non-branching, Monocapsule, Bicarpels quadriloculi (NMB) type showed higher ratio for capsule setting compared with Non-branching, Monocapsule, Quadricarpels octoloculi (NMQ) type. Non-branching, Tricapsules, Quadricarpels octoloculi(NTQ) type presented lower ratio for capsule setting than non-branching, tricapsules, bicarpels quadriloculi(NTB) type. The number of flowers by flower setting position was the highest on lower part, intermediate on middle part, and the lowest on higher part in NMB and NTB type. However, the number of flowers was the highest on middle part, intermediate on lower part, and lowest on higher part in NMQ and NTQ type. BMB type appeared to have the highest ratio for capsule setting when compared with the other plant types. BTB type with many flowers and capsules exhibited higher percentage for capsule setting than BTQ type with lowest capsule setting percentage. Capsule setting percentage of branch appeared to be lower than that of main stern in the branching type. The branching type had more flowers and capsules than non-branching type. Tricapsules type had more flowers and capsules per plant than monocapsule type, and bicarpels quadriloculi type had more than quadricarpels octoloculi type. However, capsule setting ratio in non-branching type was higher than in branching type. The ratio was higher in monocapsule type than in tricapsules type. Bicarpels quadriloculi type had higher ratio of capsule setting than quadricapels octoloculi type. Number of capsules per plant and capsule setting ratio are supposed to be dominated by shape of capsule (number of carpels and loculi), not by branching or number of capsules per axil. The order of number of capsules per plant was as follows; BTB, BMB, NTB, BTQ, BMQ, NTQ, NMQ, and NMB types. However, the order of capsule setting ratio was as follows: BMB, NMB, NTB, NTQ, NMQ, BMQ, BTB, BTQ types. Consequently, branching, tricapsules, bicarpels quadriloculi(BTB) type was considered as a sourse of breeding for high yielding varieties by introducing the genes govering BMB type with one capsule per axil which has high capsule setting ability.

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A Geometrical Study of Branching Pattern in Pinus densiflora Siebold & Zuccarini (소나무의 분지형에 관한 기하학적 연구)

  • Park, Bong Kyu;Hyeong Seon Choi
    • Journal of environmental and Sanitary engineering
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    • v.5 no.2
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    • pp.100-104
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    • 1990
  • The geometrical branching pattern was studied through the time by a few parameters: the branching lengths, angles and number of branches. Ratios of moving amounts of nutrients between branches was decreased more in a terminal branch than in a proximal one. As the time increased, the more branches and leaves were also increased, while the influx of sunlight was decreased in the lower portion of inner crown which increased the mortality rate of branches.

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Reliability of passive optic splitting devices is compared with fused fiber type optical coupler and planar lightwave guide type optical coupler

  • Choi Young-Bok;Cho Sung-Hyun;Oh Min-Chul;Kim Sang-In;Jeong Gi-Tae;Han Kwan-Hoon
    • 한국정보통신설비학회:학술대회논문집
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    • 2003.08a
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    • pp.49-51
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    • 2003
  • This test data informs to compare components from different manufactured coupler type. On the point of reliability, less than 1x8 output branching number, fuse type coupler was more stable than PLC type coupler. But more than 1x8 output branching number, PLC type coupler was more stable. This test data showed critical branching point, on the point of reliability.

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Chain Transfer to Monomer and Polymer in the Radical Polymerization of Vinyl Neo-decanoate

  • Balic, Robert;Fellows, Christopher M.;Van Herk, Alex M.
    • Macromolecular Research
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    • v.12 no.4
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    • pp.325-335
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    • 2004
  • Molecular weight distributions of poly(vinyl neo-decanoate) produced by the bulk polymerization of the monomer to low conversions were investigated to obtain values of the rate constants for the chain transfer to monomer ( $C_{M}$). The value of $C_{M}$ of 7.5($\pm$0.6)${\times}$10$^{-4}$ was obtained from a logarithmic plot of the number distribution at 5,25, and 5$0^{\circ}C$, which suggests that the activation energy for chain transfer is on the order of 20-25 kJ ㏖$^{-1}$ . These plots were linear between the number and weight-average degrees of polymerization, but not over the whole molecular weight range for which a significant signal was observed in the gel permeation chromatography (GPC) trace. Modeling suggests that the deviations observed at high molecular weights can be explained by branching of the chains through chain transfer to the polymer, with a branching density as low as 10$^{-5}$ , without affecting the slope at low values of the number of monomer unit, N. This deviation from the expected distribution of linear chains was used to estimate the branching densities at low conversion.ion.

New Branching Criteria for the Asymmetric Traveling Salesman Problem (비대칭 외판원 문제를 위한 새로운 분지기법)

  • 지영근;강맹규
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.19 no.39
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    • pp.9-18
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    • 1996
  • Many algorithms have been developed for optimizing the asymmectric traveling salesman problem known as a representative NP-Complete problem. The most efficient ones of them are branch and bound algorithms based on the subtour elimination approach. To increase efficiency of the branch and bound algorithm. number of decision nodes should be decreased. For this the minimum bound that is more close at the optimal solution should be found or an effective bounding strategy should be used. If the optimal solution has been known, we may apply it usefully to branching. Because a good feasible solution should be found as soon as possible and have similar features of the optimal solution. By the way, the upper bound solution in branch and bound algorithm is most close at the optimal solution. Therefore, the upper bound solution can be used instead of the optimal solution and information of which can be applied to new branching criteria. As mentioned above, this paper will propose an effective branching rule using the information of the upper bound solution in the branch and bound algorithm. And superiority of the new branching rule will be shown by comparing with Bellmore-Malone's one and carpaneto-Toth's one that were already proposed.

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Energy- and Time-Dependent Branching to Competing Paths in Coupled Unimolecular Dissociations of Chlorotoluene Radical Cations

  • Seo, Jongcheol;Kim, Seung Joon;Shin, Seung Koo
    • Bulletin of the Korean Chemical Society
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    • v.35 no.3
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    • pp.833-838
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    • 2014
  • The energy- and time-dependent branching to the competing dissociation paths are studied by theory for coupled unimolecular dissociations of the o-, m-, and p-chlorotoluene radical cations to $C_7{H_7}^+$ (benzylium and tropylium). There are four different paths to $C_7{H_7}^+$, three to the benzylium ion and one to the tropylium ion, and all of them are coupled together. The branching to the multiple paths leads to the multiexponential decay of reactant with the branching ratio depending on both internal energy and time. To gain insights into the multipath branching, we study the detailed kinetics as a function of time and internal energy on the basis of ab inito/RRKM calculations. The number of reaction steps to $C_7{H_7}^+$ is counted for each path. Of the three isomers, the meta mostly goes through the coupling, whereas the para proceeds with little or no coupling. In the beginning, some reactants with high internal energy decay fast to the benzylium ion without any coupling and others rearrange to the other isomers. Later on all three isomers dissociate to the products via long-lived intermediates. Thus, the reactant shows a multiexponential decay and the branching ratio varies with time as the average internal energy decreases with time. The reciprocal of the effective lifetime is taken as the rate constant. The resulting rate-energy curves are in line with experiments. The present results suggest that the coupling between the stable isomers is thermodynamically controlled, whereas the branching to the product is kinetically controlled.