• Magazine of the Korean Society of Agricultural Engineers
• /
• v.34 no.4
• /
• pp.39-47
• /
• 1992

Derivation of reasonable design low flows was attempted by comparative analysis of design low flows was derived by Power and SMEMAX transformations for the normalizations of skewed distribution and by Type m extremal distribution presented in the first report of this study with annual low flows in the five watersheds of main river basins in Korea. The results were anslyzed and summarized as follows. 1.Basic statistics of annual low flows for the selected watersheds were calculated by using Power and SMEMAX transformations. 2.Power thansformation has found to be the best for the normalization of skewed distribution among others including log, square root and SMEMAX transformations. 3.Design low flows for the selected watersheds were derived by the Power and SMEMAX transformations. 4.Judging by the relative suitabilities of the Type III extremal distribution, Power and SMEMAX transformation, it was found that design low flows of all methods are closer to the observed data within 10 years of the return period and those of Power transformation can be acknowledzed as a reasonable one among others from the viewpoint of the median between values of Type m extremal distribution and SMEMAX transformation in addition to closing the observed than others over 10 years of the return period.

• Journal of electromagnetic engineering and science
• /
• v.6 no.3
• /
• pp.182-188
• /
• 2006

Orthogonal frequency division multiplexing(OFDM) is very useful for the wireless communication system. However, OFDM is very sensitive to the radio frequency impairments. One of the most important major impairments is the IQ imbalance between in-phase(l) and quadrature(Q) branches in the up and down-conversion. IQ imbalance can be divided into phase and amplitude imbalances. These imbalances make constellation of signal to expand and rotate. The performance of system is severely degraded. In this paper, a closed-form for the bit error probability of the OFDM signal in IQ imbalance environment is derived in terms of the function of phase and amplitude imbalance parameters. So, it will be convenient and useful to evaluate the performance of OFDM communication system with IQ imbalance. It is confirmed that computer simulation results closely match with the results of the analytical derivation. When phase imbalance $\varphi=20^{\circ}$, amplitude imbalance $\varepsilon=0.1$; 0.3; 0.4; 0.5, BER at $10^{-5}$ is severely degraded by 1.8 dB, 3.12 dB, 4.72, and 8.44 dB, respectively.

• Journal of the Institute of Electronics Engineers of Korea SP
• /
• v.37 no.4
• /
• pp.65-71
• /
• 2000

Finite wordlength effect of the recursive implementation of SDFT(sliding-DFT) is analytically derived in this paper. Representation errors of the twiddle coefficients and the data registers are the two major causes of the spectral errors in the recursive implementation. The noise-to-signal ratio is analytically derived in terms of the coefficients wordlength, the data registers wordlength, and the DFT's block-length used in the computation Error dynamic equation is obtained from the recursive DFT and the probabilistic models for the coefficients error and the round-off error are introduced for the NSR derivation, The result of the NSR derivation is verified with the simulation data.

• Molecules and Cells
• /
• v.19 no.1
• /
• pp.46-53
• /
• 2005

Human embryonic stem (hES) cells, unlike most cells derived from adult or fetal human tissues, represent a potentially unlimited source of various cell types for basic clinical research. To meet the increased demand for characterized hES cell lines, we established and characterized nine new lines obtained from frozen-thawed pronucleus-stage embryos. In addition, we improved the derivation efficiency from inner cell masses (to 47.4%) and optimized culture conditions for undifferentiated hES cells. After these cell lines had been maintained for over a year in vitro, they were characterized comprehensively for expression of markers of undifferentiated hES cells, karyotype, and in vitro/in vivo differentiation capacity. All of the cell lines were pluripotent, and one cell line was trisomic for chromosome 3. Improved culture techniques for hES cells should make them a good source for diverse applications in regenerative medicine, but further investigation is needed of their basic biology.

• Journal of the Chungcheong Mathematical Society
• /
• v.26 no.4
• /
• pp.703-706
• /
• 2013

Let R be a commutative noetherian algebra and let ${\delta}$ be a nonzero derivation. Here we determine the prime ideals of the skew polynomial algebra R[z;${\delta}$] and the Poisson prime ideals of R[z;${\delta}$]p.

• Journal of the Chungcheong Mathematical Society
• /
• v.26 no.4
• /
• pp.743-748
• /
• 2013

The purpose of this note is to introduce interesting and useful properties differential-basis and p-basis in theorem 3.3. The result gives a existence differential basis of $S^P$ [$[{\Lambda}_1]$](S) which has a p-basis over $S^p$ ($S^p[{\Lambda}_1]$).

• The Pure and Applied Mathematics
• /
• v.26 no.4
• /
• pp.305-313
• /
• 2019

Using the fixed point method, we prove the Hyers-Ulam stability of 3-Lie homomorphisms and 3-Lie derivations in 3-Lie algebras for Cauchy-Jensen functional equation.

• Bulletin of the Korean Mathematical Society
• /
• v.47 no.4
• /
• pp.663-673
• /
• 2010

This work was intended as an attempt to introduce and investigate the Connes-amenability of module extension of dual Banach algebras. It is natural to try to study the $weak^*$-continuous derivations on the module extension of dual Banach algebras and also the weak Connes-amenability of such Banach algebras.

• Kyungpook Mathematical Journal
• /
• v.55 no.4
• /
• pp.893-907
• /
• 2015

The Hyers-Ulam-Rassias stability of the k-th partial ternary quadratic derivations is investigated in non-Archimedean Banach ternary algebras and non-Archimedean $C^*$-ternary algebras by using the fixed point theorem.

• Wind and Structures
• /
• v.8 no.4
• /
• pp.283-294
• /
• 2005

This paper describes the work of the Working Group on wind pressure coefficients on low-rise structures, one of the groups set up by the International Association of Wind Engineering in 1999. General aspects of wind loading on low-rise structures are summarized. The definition, derivation and codification of loading coefficients is described. Comparisons of pressure coefficients on low rise structures are made between a selection of wind loading standards. Recommendations for consistency and for the harmonization of these coefficients are given.