• Title/Summary/Keyword: Cones

Search Result 295, Processing Time 0.025 seconds

CURVATURE BOUNDS OF EUCLIDEAN CONES OF SPHERES

  • Chai, Y.D.;Kim, Yong-Il;Lee, Doo-Hann
    • Bulletin of the Korean Mathematical Society
    • /
    • v.40 no.2
    • /
    • pp.319-326
    • /
    • 2003
  • In this paper, we obtain the optimal condition of the curvature bounds guaranteeing that Euclidean cones over Aleksandrov spaces of curvature bounded above preserve the curvature bounds, by considering the Euclidean cone CS$_{r}$ $^{n}$ over n-dimensional sphere S$_{r}$ $^{n}$ of radius r. More precisely, we show that for r<1, the Euclidean cone CS$_{r}$ $^{n}$ of S$_{r}$ $^{n}$ is a CBB(0) space, but not a CBA($textsc{k}$)-space for any real $textsc{k}$$\in$R.

A WEIGHTED-PATH FOLLOWING INTERIOR-POINT ALGORITHM FOR CARTESIAN P(κ)-LCP OVER SYMMETRIC CONES

  • Mansouri, Hossein;Pirhaji, Mohammad;Zangiabadi, Maryam
    • Communications of the Korean Mathematical Society
    • /
    • v.32 no.3
    • /
    • pp.765-778
    • /
    • 2017
  • Finding an initial feasible solution on the central path is the main difficulty of feasible interior-point methods. Although, some algorithms have been suggested to remedy this difficulty, many practical implementations often do not use perfectly centered starting points. Therefore, it is worth to analyze the case that the starting point is not exactly on the central path. In this paper, we propose a weighted-path following interior-point algorithm for solving the Cartesian $P_{\ast}({\kappa})$-linear complementarity problems (LCPs) over symmetric cones. The convergence analysis of the algorithm is shown and it is proved that the algorithm terminates after at most $O\((1+4{\kappa}){\sqrt{r}}{\log}{\frac{x^0{\diamond}s^0}{\varepsilon}}\)$ iterations.

VECTOR OPTIMIZATION INVOLVING GENERALIZED SEMILOCALLY PRE-INVEX FUNCTIONS

  • GUPTA, SUDHA;SHARMA, VANI;CHAUDHARY, MAMTA
    • Journal of applied mathematics & informatics
    • /
    • v.33 no.3_4
    • /
    • pp.235-246
    • /
    • 2015
  • In this paper, a vector optimization problem over cones is considered, where the functions involved are $\eta$-semidifferentiable. Necessary and sufficient optimality conditions are obtained. A dual is formulated and duality results are proved using the concepts of cone $\rho$-semilocally preinvex, cone $\rho$-semilocally quasi-preinvex and cone $\rho$-semilocally pseudo-preinvex functions.

THE PEETRE K-METHOD IN STRONG $\lambda$-K-MONOTONE SPACES

  • Lee, Chongsung
    • Bulletin of the Korean Mathematical Society
    • /
    • v.31 no.2
    • /
    • pp.297-308
    • /
    • 1994
  • In [5], M. Cwikel and J. Peetre showed that some Banach couples are Calderon pairs and every K-monotone cones in that couples can be constructed by the Peetre K-method. With the help of theorem 4 in [3], we can extend the above result to the K-monotone spaces. In [4], M. Cwikel provided the proof of therem 4 in [3] and also mentioned that some theorems in [5] which were stated in terms of K-monotone cones can be extended to K-monotone spaces. But M. Cwikel and J.Peetre's results only cover the case when over bar A = over bar B. We extend this result to the case when over bar A.neq. over bar B. In this case, we need a condition stronger than that the K-monotone space.

  • PDF

AN OPTIMAL CONTROL APPROACH TO CONFORMAL FLATTENING OF TRIANGULATED SURFACES

  • PARK, YESOM;LEE, BYUNGJOON;MIN, CHOHONG
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.23 no.4
    • /
    • pp.351-365
    • /
    • 2019
  • This article presents a new approach for conformal flattening with optimal cone singularity. The algorithm here takes an optimal control for selecting optimal cones and uses the Ricci flow to force the flattening. This work is considered as a modification to the work of Soliman et al. [1] in the sense that they make use of the Yamabe equation for the flattening, which is an approximation of the Ricci flow. We present a numerical algorithm based on the optimal control with the mathematical background. Several numerical results validate that our method is optimal in total cone angle and usage of the Ricci flow ensures the conformal flattening while selecting optimal cones.

Interaction of Nonreceptor Tyrosine-Kinase Fer and p120 Catenin Is Involved in Neuronal Polarization

  • Lee, Seung-Hye
    • Molecules and Cells
    • /
    • v.20 no.2
    • /
    • pp.256-262
    • /
    • 2005
  • The neuronal cytoskeleton is essential for establishment of neuronal polarity, but mechanisms controlling generation of polarity in the cytoskeleton are poorly understood. The nonreceptor tyrosine kinase, Fer, has been shown to bind to microtubules and to interact with several actin-regulatory proteins. Furthermore, Fer binds p120 catenin and has been shown to regulate cadherin function by modulating cadherin-${\beta}$-catenin interaction. Here we show involvement of Fer in neuronal polarization and neurite development. Fer is concentrated in growth cones together with cadherin, ${\beta}$-catenin, and cortactin in stage 2 hippocampal neurons. Inhibition of Fer-p120 catenin interaction with a cell-permeable inhibitory peptide (FerP) increases neurite branching. In addition, the peptide significantly delays conversion of one of several dendrites into an axon in early stage hippocampal neurons. FerP-treated growth cones also exhibit modified localization of the microtubule and actin cytoskeleton. Together, this indicates that the Fer-p120 interaction is required for normal neuronal polarization and neurite development.

The Study on the Effects of Various N.P.K. Fertilization Levels on Hop Yield (NPK의 시비수준이 호프수량에 미치는 영향에 관한 연구)

  • 임웅규
    • Journal of Plant Biology
    • /
    • v.19 no.2
    • /
    • pp.37-40
    • /
    • 1976
  • The experiment designed to obtain information relative to the favourable levels to apply N.P.K fertilizer was conducted at the hop garden of College of Agriculture, S.N.U. in 1975. The varieties used were 1-year-old Cascade, Hallertau and Shinshuwase. The design of the experiment was a split plot design with 3 replications. Yields were recorded as fresh weight of harvested cones in gram per split plot. The results obtained from the experiment were as follows: 1. The results from analysis of the data for 3 varieties indicated that significant increase in yield were found due to the application of 46g N, 20g P2O5 and 60kg K2O per plant, although higher level thn the above caused a remarkable reduction of yield. 2. The individual fresh weight of harvested cones was significantly increased with application of nitrogen, phosphorus and potash, regardless of fertilizer levels. 3. Analysis of variance for yields showed that there were no significant interaction between fertilizer level and variety, i.e., all varieties used might require the same fertilizer level.

  • PDF

Study on the nonuniform modification of laser ablated HTS surface (레이저 융제된 HTS 표면의 불균일한 변조에 대한 연구)

  • Jeong, Young-Sik;Lee, Sang-Yeol
    • Proceedings of the KIEE Conference
    • /
    • 1996.11a
    • /
    • pp.251-253
    • /
    • 1996
  • High temperature superconducting (HTS) target has been irradiated by excimer laser beam. The surface of HTS target has been changed and showed the formation of cones. The laser ablated HTS target surface has been systematically studied using a scanning electron microscope. A KrF excimer laser with a wavelength of 248 nm was used to ablate the HTS YBCO target. The size of laser beam focused on the target showed a rectangular shape of $9.7{\times}2\;mm^2$. The image of SEM shows the difference between the shapes of cones fanned at the boundary and at the center of the ablated area after 1,000 laser pulses.

  • PDF

Numerical optimization of flow uniformity inside an under body- oval substrate to improve emissions of IC engines

  • Om Ariara Guhan, C.P.;Arthanareeswaran, G.;Varadarajan, K.N.;Krishnan, S.
    • Journal of Computational Design and Engineering
    • /
    • v.3 no.3
    • /
    • pp.198-214
    • /
    • 2016
  • Oval substrates are widely used in automobiles to reduce the exhaust emissions in Diesel oxidation Catalyst of CI engine. Because of constraints in space and packaging Oval substrate is preferred rather than round substrate. Obtaining the flow uniformity is very challenging in oval substrate comparing with round substrate. In this present work attempts are made to optimize the inlet cone design to achieve the optimal flow uniformity with the help of CATIA V5 which is 3D design tool and CFX which is 3D CFD tool. Initially length of inlet cone and mass flow rate of exhaust stream are analysed to understand the effects of flow uniformity and pressure drop. Then short straight cones and angled cones are designed. Angled cones have been designed by two methodologies. First methodology is rotating flow inlet plane along the substrate in shorter or longer axis. Second method is shifting the flow inlet plane along the longer axis. Large improvement in flow uniformity is observed when the flow inlet plane is shifted along the direction of longer axis by 10, 20 and 30 mm away from geometrical centre. When the inlet plane is rotated again based on 30 mm shifted geometry, significant improvement at rotation angle of $20^{\circ}$ is observed. The flow uniformity is optimum when second shift is performed based on second rotation. This present work shows that for an oval substrate flow, uniformity index can be optimized when inlet cone is angled by rotation of flow inlet plane along axis of substrate.