• The Journal of Korean Institute of Communications and Information Sciences
• /
• v.21 no.9
• /
• pp.2355-2361
• /
• 1996

Convergence analysis on Godard's quartic(GQ) algorithm used for blind equalization is accomplished in this paper. First, we explain the local behavior of the GQ algoithm around the global minimum point of the average performance function. Then we consider the geometry of the average performance function. The main result is that a good initial parameter vector of the GQ algorithm can be chosen based on the information of the geometry of the average performance function.

• Proceedings of the KIEE Conference
• /
• 2003.07d
• /
• pp.2352-2354
• /
• 2003

An apparatus and method for imposing a desired average radial force on tire by calculating the current average force between the tire and load wheel based on the average radial force and radial distance between the tire load wheel over the last previous complete revolution of the tire, the spring constant of the tire and the current radial distance between the tire and the load wheel.

• Bulletin of the Korean Chemical Society
• /
• v.17 no.1
• /
• pp.61-65
• /
• 1996

The semiempirical time-dependent Hartree-Fock PM3 calculations have been performed on three polyene systems. In order to study the nonlinear optical properties, we calculated the frequency-dependent first-, second-, and third-order polarizabilities of thiophene-, furan-, pyrrole-nitro polyene systems. The PM3 predicted average and longitudinal polarizabilties increase in the order: thiophene- > pyrrole- > furan-nitro polyene systems. The PM3 predicted limiting average second-order polarizabilities show the order: pyrrole- > furan- > thiophene-nitro polyene systems. The average and longitudinal third-order polarizabilties have the following order: pyrrole- > thiophene- > furan-nitro polyene systems. In these trends, we sugest that pyrrole group is the best donor group among the three polyene systems.

• Journal of the Korean Magnetics Society
• /
• v.8 no.6
• /
• pp.395-399
• /
• 1998

평면 실리콘 헤드를 사용한 디스크 드라이브(hard disk:HDD) 시스템의 average bit error rate(ABER)를 계산하였다. ABER을 구하기 위해 3차원 유한 요소법을 사용하여 헤드 자장 분포를 구하고 error rate response surface(ERRS)를 구하엿다. 다음에 track misregistration(TMR)과 계산되어진 ERRS를 컨볼루션하여 ABER을 시뮬레이션 하였다. 허용할 수 잇는 에러 율이 10-6이라 하고 트랙 피치가 3.7$\mu$m일 때, 요구되는 TMR은 0.36$\mu$m이었다. 이는 트랙 피치의 9.7이었다.

• Journal of the Optical Society of Korea
• /
• v.19 no.3
• /
• pp.237-240
• /
• 2015

We derived the average bit error rate (BER) of coherent free-space optical (FSO) systems with digital binary phase shift keying (BPSK) modulations over atmospheric turbulence channels with a gamma-gamma distribution. To obtain a generalized derivation in a closed-form expression, we used special integrals and transformations of the Meijer G function. Furthermore, we numerically analyzed and simulated the average BER behavior according to the average SNR for different turbulence strengths. Simulation results are demonstrated to confirm the analytical results.

• Communications of the Korean Mathematical Society
• /
• v.34 no.3
• /
• pp.981-989
• /
• 2019

In this paper we deal with some shadowing properties of discrete dynamical systems on a compact metric space via the density of subdynamical systems. Let $f:X{\rightarrow}X$ be a continuous map of a compact metric space X and A be an f-invariant dense subspace of X. We show that if $f{\mid}_A:A{\rightarrow}A$ has the periodic shadowing property, then f has the periodic shadowing property. Also, we show that f has the finite average shadowing property if and only if $f{\mid}_A$ has the finite average shadowing property.

• Journal of the military operations research society of Korea
• /
• v.8 no.1
• /
• pp.99-107
• /
• 1982

This paper is concerned with the optimality of exponential smoothing applied to the general IMA process with different moving average and differencing orders. Numerical experiments were performed for IMA(m,n) process with various combinations of m and n, and the corresponding forecast errors were compared. Results show that the higher differencing order is more critical to the optimality of exponential smoothing, i.e., the IMA process with the higher moving average order, forecasted by exponential smoothing, has comparatively smaller forecast error. If the difference between the differencing order and the moving average order becomes larger, the accuracy of forecast by exponential smoothing declines gradually.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
• /
• 2000.06a
• /
• pp.134-141
• /
• 2000

The real area of contacts, average film thickness, mean real pressure, and mean hydrodynamic pressure are investigated numerically in this study, especially for the parallel thrust bearing. Model surface is generated numerically with given autocorrelation function and some surface profile parameters. Then the average Reynolds equation contained flow factors and contact factor is applied to predict the effects of surface roughness in mixed lubrication regimes. In this equation, flow factors are defined as correction terms to smooth out high frequency surface roughness and contact factor is introduced to relieve from obtaining the average film thickness. Therefore the computation time to obtain h can be reduced.

• Journal of the Korean Society of Physical Medicine
• /
• v.6 no.3
• /
• pp.353-360
• /
• 2011

Purpose : The purpose of this study was to compare the effect of muscle strength by stimulation of russian current and low frequency. Methods : The subjects were thirty young healthy volunteers who were divided into two groups including russian current group(n=15) and low frequency group(n=15). The intervention was applied totally 12 times (1 time, 10 minute) for 4weeks in each group. The peak torque and average power were measured and analysed using Biodex system 4 before the treatment, after 2 weeks, 4 weeks. Results : As a result, russians currents and low frequency stimulation increased significantly average power and peak torque with the lapse of time. However, there were not significant differences of the average power and peak torque between the groups in all periods. Conclusion : In conclusion, russians currents and low frequency stimulation had no differences in the increase of muscle strength.

• Asian-Australasian Journal of Animal Sciences
• /
• v.3 no.4
• /
• pp.319-322
• /
• 1990

The studies were conducted on 12 lactating animals comprising of six Karan Swiss (KS) cows and six Murrah buffaloes in second and third lactation. At the start of experiment the cows had completed on an average 51 days in lactation and were yielding an average of 15.1 kg milk a day. The buffaloes had completed 53 days in lactation and were yielding an average of 11.6 kg milk a day. At fortnightly intervals jugular blood samples were drawn at morning, noon, evening and night hours. Plasma growth hormone concentrations were highest during morning and thereafter decreased. In both the species there was a definite trend in the change of growth hormone concentrations during the day. In general growth hormone concentration decreased as the stage of lactation advanced. The overall average values of plasma growth hormone in cows and buffaloes were 2.95 and 2.48 ng/ml which were not statistically different. With the advancing lactation, the decline in milk yields in both the species was positively correlated with the growth hormone concentrations.