• Proceedings of the Korea Electromagnetic Engineering Society Conference
• /
• 2001.11a
• /
• pp.25-28
• /
• 2001

In this paper. to eliminate a cross-polarization interference caused by co-channel dual polarization technique of digital radio relay system(DRRS), a cross-polarization interference canceller(XPIC) is analysed in terms of the analytical modeling, digital design, and its performance. By virtue of a 13-tap adaptive equalizer and XPIC, about 23dB in XPIC improvement can be obtained by computer simulation. To show the operation of designed XPIC, some simulated results are reviewed under 64-QAM DRRS with co -channel dual Polarization.

• Proceedings of the Korea Contents Association Conference
• /
• 2004.05a
• /
• pp.503-512
• /
• 2004

The most important virtue that S&T information should possess is the promptness. In the era of global competition, it is very important to catch the technical trends and R&D policy of advanced countries in time. In this paper, we surveyed S&T trends information service in advanced and competing countries including USA, Japan, European countries, and china. Based on the survey result, we show that the "Overseas S&T Trends Information Service" provided by KISTI is dominant to those of other countries

• Bulletin of the Korean Mathematical Society
• /
• v.49 no.3
• /
• pp.495-510
• /
• 2012

Let $X_1$, $X_2$,${\ldots}$, $X_n$ be a sequence of independent and identically distributed random variables with common distribution function $F$. Convergence rates for the moments of extremes are studied by virtue of second order regularly conditions. A unified treatment is also considered under second order von Mises conditions. Some examples are given to illustrate the results.

• Tribology and Lubricants
• /
• v.15 no.2
• /
• pp.164-170
• /
• 1999

Gerotor is widely used as a hydraulic pump or motor, by virtue of its volume changing ability. Performance deterioration of a gerotor hydraulic motor mainly due to the wear come from the contact between inner rotor with trochoidal curve and outer rotor with circular arc profile. This research covers the basic investigation about the contact forces of a gerotor hydraulic motor using analytic method. The influence of the eccentricity and the radius of circular arc teeth on the contact stress was evaluated.

• Journal of Marine Bioscience and Biotechnology
• /
• v.2 no.4
• /
• pp.201-208
• /
• 2007

Polychlorinated biphenyls (PCBs) are anthropogenic contaminants found globally in water, ice, soil, air and sediment. Modern analytical techniques allow us to determine these chemicals in environmental matrices at parts per trillion levels or lower. Environmental forensic on PCBs opens up new avenues of investigation such as transport and fate of water masses in oceans, sedimentation, onset of primary production, migration of marine mammals, their population distribution and pharmacokinetics of drugs inside organisms. By virtue of persistence, bioaccumulation, bioconcentration and structure-activity relationship PCBs emerge as unconventional chemical tracers of new sort.

• Proceedings of the Korea Concrete Institute Conference
• /
• 1998.10b
• /
• pp.633-636
• /
• 1998

The use of concrete pavements is increasing by virtue of durability and excellent load resisting capacity. But cracks and demage in concrete pavements may be occurred by continuous reciclic load, as time goes by. Therefore, transverser contraction joints are constructed in concrete pavements to relieve tensile stresses, and when properly spaced they control the location of transverse cracks.

• Proceedings of the Korean Institute of Intelligent Systems Conference
• /
• 2002.12a
• /
• pp.375-378
• /
• 2002

In this paper we propose parallel GA to optimize mutation rate and crossover rate using server-client model. The performance of GA depend on the good choice of crossover and mutation rates. Although many researcher has been study about the good choice, it is still unsolved problem. proposed GA optimize crossover and mutation rates trough evolving subpopulation. In virtue of the server-client model, these parameters can be evolved rapidly with relatively low-grade

• Bulletin of the Korean Chemical Society
• /
• v.22 no.6
• /
• pp.593-596
• /
• 2001

The reaction of [(2-N,N-dimethylaminomethyl) pheny] methylvinychlorosiane with t-BuLi in hexane solvent gave dimers, five isomeric 1,3-disilacyslobutanes which were weparated and charaterized. In trapping experiments with various trapping agents, no corresponding silene-trapping aduct was observed. We suggest that more important species for the formation of five isomeric dimers might be the zwitterionic species generated by virtue of intramolecular donor atom rather than the silene.

• Bulletin of the Korean Chemical Society
• /
• v.22 no.6
• /
• pp.597-604
• /
• 2001

The reaction of [(2-N,N-dimethylaminomethyl) pheny] methylvinychlorosiane with t-BuLi in hexane solvent gave dimers, five isomeric 1,3-disilacyslobutanes which were weparated and charaterized. In trapping experiments with various trapping agents, no corresponding silene-trapping aduct was observed. We suggest that more important species for the formation of five isomeric dimers might be the zwitterionic species generated by virtue of intramolecular donor atom rather than the silene.

• Korean Journal of Mathematics
• /
• v.26 no.4
• /
• pp.675-681
• /
• 2018

In the paper, by virtue of techniques in combinatorial analysis, the authors simplify three families of nonlinear ordinary differential equations in terms of the Stirling numbers of the first kind and establish a new family of nonlinear ordinary differential equations in terms of the Stirling numbers of the second kind.