• Title/Summary/Keyword: k-covers

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Nonparametric Granger Causality Test

  • Jeong, Ki-ho;Nishiyama, Yoshihiko
    • Journal of the Korean Data and Information Science Society
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    • v.18 no.1
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    • pp.195-210
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    • 2007
  • This paper develops a consistent nonparametric test for Granger causality in the context of strong-mixing process, which covers a large class of stationary processes including ARMA and ARCH models. The previously proposed tests require absolute regularity ($\beta$-mixing) more stringent than the strong-mixing condition. We prove the consistency of the test under a high level assumption on the approximation error of U statistic by its projection. Due to the sample splitting, the test statistic we propose is asymptotically normally distributed under the null.

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Different Approaches to Design a Meteorological Buoy for Weather Monitoring Purposes

  • Lee, Chee-Cheong;Park, Soo-Hong
    • Journal of information and communication convergence engineering
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    • v.8 no.3
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    • pp.301-306
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    • 2010
  • This project is to study and design a meteorological buoy. It mainly covers and compares two approaches to design a meteorological buoy where their functions are same. The comparison will be made between mechanical structure, type of sensors, and electronics system design and power consumption issues.

Research and Development Status of Dog-Horse Robot (견마형로봇 연구개발 현황)

  • Park, Yong-Woon;Chae, Jeong-Sook
    • Proceedings of the IEEK Conference
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    • 2008.06a
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    • pp.127-128
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    • 2008
  • Research and development status of Dog-Horse robot is presented based on the critical technology issues which generates severe problems or hard trade-offs to meet the general requirement of system and new technologies. This paper covers from architectural problems to specific technology to overcome the operational requirement. Technology development based on operation requirement derived new research challenges as well as advanced development for system adaptation.

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Four Species of Jumping Spiders (Areaneae: Salticidae) from China

  • Xian-Jin Peng;Joo-Pil Kim
    • Animal cells and systems
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    • v.2 no.4
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    • pp.411-414
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    • 1998
  • One novel species, Phaeacius yunnanensis n. sp. and three species new to China, Brettus albolimbattus, Hyllus lacertosus and Ptocasius kinhi of the jumping spider.belonging to the family Salticidae, are described based on the materials collected from Yunnan Province, China. The new species is similar to Phaecius lancerarius, but can be distinguished by secondary conductor covers on the emblus. That of the latter below the emblous, retro1aterial tibial apophysis, is much more slender and with an abdominal pattern.

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Graphene growth from polymers

  • Seo, Hong-Kyu;Lee, Tae-Woo
    • Carbon letters
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    • v.14 no.3
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    • pp.145-151
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    • 2013
  • Graphene is a fascinating material with excellent electrical, optical, mechanical, and chemical properties. Remarkable progress has been made in the development of methods for synthesizing large-area, high-quality graphene. Recently, the chemical vapor deposition method has opened up the possibility of using graphene for electronic devices and other applications. This review covers simple and inexpensive methods to grow graphene using polymers as solid carbon sources; which do not require an additional process to transfer graphene from the growth substrate to the receiver substrate.

SOME REMARKS ON COTORSION ENVELOPES OF MODULES

  • Kim, Hae-Sik;Song, Yeong-Moo
    • Bulletin of the Korean Mathematical Society
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    • v.44 no.4
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    • pp.589-596
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    • 2007
  • In this paper we prove that the extension of pure injective module is pure injective if and only if the cotorsion envelope and the pure injective envelope of any R-module M are isomorphic over M. And we prove that if the product of pure injective envelopes of flat modules is a pure injective envelope and the product of flat covers is a flat cover, then the product of cotorsion envelopes is a cotorsion envelope.

TOPOLOGICAL COMPLEXITY OF SEMIGROUP ACTIONS

  • Yan, Xinhua;He, Lianfa
    • Journal of the Korean Mathematical Society
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    • v.45 no.1
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    • pp.221-228
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    • 2008
  • In this paper, we study the complexity of semigroup actions using complexity functions of open covers. The main results are as follows: (1) A dynamical system is equicontinuous if and only if any open cover has bounded complexity; (2) Weak-mixing implies scattering; (3) We get a criterion for the scattering property.

ASYMPTOTIC RUIN PROBABILITIES IN A GENERALIZED JUMP-DIFFUSION RISK MODEL WITH CONSTANT FORCE OF INTEREST

  • Gao, Qingwu;Bao, Di
    • Journal of the Korean Mathematical Society
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    • v.51 no.4
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    • pp.735-749
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    • 2014
  • This paper studies the asymptotic behavior of the finite-time ruin probability in a jump-diffusion risk model with constant force of interest, upper tail asymptotically independent claims and a general counting arrival process. Particularly, if the claim inter-arrival times follow a certain dependence structure, the obtained result also covers the case of the infinite-time ruin probability.

Distributions of Trees Along the Site Specific Micro-environmental Factors Related to the Topography of Kwangnung, Korea

  • Lim, Jong-Hwan;Shin, Joon-Hwan
    • Proceedings of The Korean Society of Agricultural and Forest Meteorology Conference
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    • 2001.06a
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    • pp.135-138
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    • 2001
  • The study area, the Kwangnung Experimental Forest (KEF) region is located at the west-central portion of the Korean peninsula (Figure 1), and covers 2, 240ha. Elevations range about from 90m to 600m, and the highest peak is Mt. Jukyeopsan (600.6m). Kwangnung Natural Reserve Forest area is about 1, 200ha, which has been protected from human activities for a long time.(omitted)

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Tris(2-methoxyphenyl)phosphine as a Highly Active Ligand for the Synthesis of Biaryls by Suzuki Coupling Reaction

  • Kang, Pill-Seong;Ko, Sung-Bo;Ko, Jang-Myoun;Park, Jeong-Ho
    • Bulletin of the Korean Chemical Society
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    • v.30 no.11
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    • pp.2697-2700
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    • 2009
  • A $Pd(OAc)_2/(o-MeOPh)_3P$ system has been developed for the catalytic Suzuki coupling of aryl bromides with arylboronic acids. Our catalyst system covers a broad spectrum of commonly available arylboronic acids and aryl bromides to provide biaryls in very good yields. The catalyst system works very well in the synthesis of sterically hindered biaryls.