• Bulletin of the Korean Mathematical Society
• /
• v.37 no.1
• /
• pp.191-207
• /
• 2000

Let R be a ommutative ring with unity and F a finite free R-module. For a nonnegative integer r, there exists a natural filtration of$S_r(S_2F)$ such that its associated graded module is isomorphic to $\Sigma_{{\lambda}{\epsilon}{\tau}_r}\;L_{\lambda}F$, where ${\Gamma}_{\gamma}$ set of partitions such that $$\mid${\lambda}$\mid$-2r,{{\widetilde}{\lambda}}-{{\widetilde}{\lambda}}_1},...,{{\widetilde}{\lambda}}_k},\;each\;{{\widetilde}{\lambda}}_t}$,is even. We call such filtrations plethysm formulas. We extend the above plethysm formula to the version of chain complexes. By plethysm formula we mean the composition of universally free functors. $Let{\emptyset}:G->F$ be a morphism of finite free R-modules. We construct the natural decomposition of $S_{r}(S_2{\emptyset})$,up to filtrations, whose associated graded complex is isomorphic to ${\Sigma}_{{\lambda}{\varepsilon}{\tau}}_r}\;L_{\lambda}{\emptyset}$.

• Journal of the Korean Chemical Society
• /
• v.26 no.5
• /
• pp.265-273
• /
• 1982

The effect of ${\pi}$ bonds on the calculated dipole moments for square planar and tetrahedral [M(II)$O_2S_2$]] type complexes has been investigated by two different approaches. One is the approximate molecular orbital method based on the assumption that the mixing coefficient CM of the valence basis sets for the central metal ion and the appropriate ligand orbitals is equal for all ${\sigma}$ and ${\pi}$ bonding molecular orbitals. The other is the more refined calculation based on the semiempirical LCAO-MO method. If ${\sigma}$ bonds only are assumed to be formed, the calculated dipole moments for square planar and tetrahedral complexes are lower than those of the experimental values. If the contribution of ${\pi}$ bonds to the calculated dipole moments are fully considered, the calculated dipole moments for both square planar and tetrahedral [M(II)$O_2S_2$]] type complexes are higher than the experimental values. However if ${\pi}$ bonds are assumed to be delocalzed, the calculated dipole moments for tetrahedral [M(II$O_2S_2$]] type complexes fall in the range of the experimental values, but those for square planar complexes deviate from the experimental values. These results suggest that [M(II)$O_2S_2$]] type complexes may have the tetrahedral structure in inert solvent solution. This structure is in agreement with the experimental one. The calculated dipole moments for tetrahedral [M(II)$O_2S_2$]] type complexes indicate that the contribution of ${\pi}$ bonds to the calculated dipole moments may not be neglected.

• The Bulletin of The Korean Astronomical Society
• /
• v.43 no.1
• /
• pp.57.4-58
• /
• 2018

We explore the role of various environments in triggering star formation (SF) and narrow-line active galactic nucleus (AGN) in SDSS spiral galaxies and the SF-AGN connection, using a volume-limited sample with $M_r$ < -19.5 and 0.02 < z < 0.055 selected from the SDSS Release 7. To avoid the dependency of AGN activity on bulge mass, the central velocity dispersion of the sample galaxies is limited to have a narrow range of $130{\leq}{\sigma}{\leq}200km\;s^{-1}$. We note that in gas sufficient galaxies, AGN feeding lags behind starburst, whereas as the gas exhausts, the SF slows down and AGN seems to even prevent the SF, and thus divide the high-${\sigma}$ sample into two subsamples according to their cold gas content at central region traced by fiber star formation rate, $SFR_{fib}$. We find that a high density (cluster) environment causes a significant increase in AGN activity as well as gas depletion in host galaxies. However, the finding is only noticeable in the high-${\sigma}$ and low $SFR_{fib}$ sample. It seems that a galaxy interaction with the nearest neighbor directly affects the SF of the central region. However, it is unclear whether it directly affects AGN activity.

• The Korean Journal of Food And Nutrition
• /
• v.24 no.2
• /
• pp.258-267
• /
• 2011

14-3-3 is a highly conserved, ubiquitously expressed protein family. It associates with diverse cellular proteins through its specific phosphoserine/phosphothreonine-binding activity and thus contributes to the regulation of crucial cellular processes such as metabolism, signal transduction, cell-cycle control, apoptosis, protein trafficking, transcription and stress responses. This study aims to determine changes in levels of 14-3-3 isoforms and 14-3-3 - associated proteins in Helicobacter pylori(H. pylori)-infected gastric epithelial AGS cells. AGS cells were stimulated with H. pylori(NCTC 11637) at the ratio of 300:1(bacterium:cell). Western blot analysis revealed that 14-3-3 $\sigma$ was elevated at 3 hr after H. pylori treatment. Other isoforms were not significantly affected by H. pylori infection. Using immunoprecipitation to 14-3-3 $\sigma$, followed by proteomic analysis, we found that S phase kinase associated protein isoform 2 bound to 14-3-3 $\sigma$ has increased. In contrast, three proteins (DEAD-box polypeptide 3, heterogeneous nuclear ribonucleoprotein H2 and WD repeat-containing protein isoform 1) bound to 14-3-3 decreased by H. pylori infection. Our results suggest that 14-3-3 may play an important regulatory role in H. pylori-induced signal transduction in gastric epithelial cells.

• Journal of the Korea Academia-Industrial cooperation Society
• /
• v.7 no.2
• /
• pp.101-106
• /
• 2006

The optimum design of turbine blade at minimized fatigue life can be derived by the statistical fatigue analysis in this study, The optimum value of positions in the axes of X and Y at turbine blade can be found by design of experiments on the condition that the value of fillet radius is fixed to minimize the fatigue life. The degree of uncertainty about process at the factors in the axes of X and Y can be calculated by six sigma analysis. The optimum value of fillet radius is determined by utilizing the robust design at uncertain condition. It is concluded that maximum von Mises stress can decreased by 20% and the fatigue life can be double.

• Journal of Ocean Engineering and Technology
• /
• v.28 no.4
• /
• pp.306-313
• /
• 2014

Super duplex stainless steels (sDSS) are excellent for use under severely corrosive conditions such as offshore and marine applications like pipelines and flanges. sDSS has better mechanical properties and corrosion resistance than the standard duplex stainless steel (DSS) but it is easier for a sigma phase to appear, which depresses the mechanical property and corrosion resistance, compared to DSS, because sDSS has a higher alloy element than DSS. In addition, sDSS has a feeble ductile-brittle transition temperature (DBTT) because it has a 50% ferrite microstructure. In the actual operating environment, sDSS would be thermally affected by welding and a sub-zero temperature environment. This study analyzed how precipitated sDSS behaves at a sub-zero temperature through annealing heat treatment and a sub-zero tensile test. Six types of specimens with annealing times of up to 60 min were tested in a sub-zero chamber. According to the experimental results, an increase in the annealing time reduced the elongation of sDSS, and a decrease in the tensile test temperature raises the flow stress and tensile stress. In particular, the elongation of specimens annealed for 15 min and 30 min was clearly lowered with a decrease in the tensile test temperature because of the increasing sigma phase fraction ratio.

• Korean Business Review
• /
• v.22 no.2
• /
• pp.87-109
• /
• 2009

Through literature review, this paper studies the development stages of Quality Circles and 6 sigma which are representative of domestic quality improvement activities. Thus, using the judgement guideline of Van der Wiele's classification for fad, fashion, and fit, the development stages for existing researches of Quality Circles and 6 sigma are qualitatively classified by research themes. In addition to, academic and business perspective are examined to grasp a current position of domestic quality improvement activities. As a result of the findings of current development stages of quality improvement activities, domestic Quality Circles which are not going to move on a fit stage are currently classified as the stage between fashion and fit, and 6 sigma activities are currently classified as the stage of fashion.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.27 no.2
• /
• pp.123-129
• /
• 2017

Objectives: The purpose of this study is to enhance the application of analytical method of polar solvents(alcohols) by GCOTC (gas chromatography open tubular column) through the system suitability test(SST) to estimate the whole chromatographic system performance(integral part). Methods: To perform the SST, carried out repeatability(n=6) as analytical method of polar solvents by GCOTC, got the retention time($t_R$), standard deviation(${\sigma}_{n-1}$) of $t_R$, baseline width($w_b=4{\sigma}_{n-1}$) and calculated dead time($t_m$) by $v_m=d^2{\pi}L(f/4)$ and $v_m=t_m$ x flow rate. Results: In this experiment, obtained the basic data, there were $t_m=2$ min, methanol($t_R=3.569$, ${\sigma}_{n-1}=0.01$, $w_b=0.04$), ethanol ($t_R=3.892$, ${\sigma}_{n-1}=0.004$, $w_b=0.016$), isopropanol($t_R=4.209$, ${\sigma}_{n-1}=0.004$, $w_b=0.016$). By using these data, calculated the corrected retention time($t_R{^{\prime}}$), capacity factor(k), separation factor(${\alpha}$), number of theoretical plate(n) and resolution($R_s$) for SST and got the good results. Conclusions: Through the SST, could reconfirm the whole chromatographic performance system(integral part) for analytical method of polar solvents by GCOTC. Therefore, this analytical method expect to be widely applied at the related areas.

• The Bulletin of The Korean Astronomical Society
• /
• v.39 no.1
• /
• pp.54.1-54.1
• /
• 2014

Kyung Hee University has been developing a CubeSat for the space science mission called SIGMA (Scientific cubesat with Instrument for Global Magnetic field and rAdiation), which includes TEPC (Tissue Equivalent Proportional Counter) and a magnetometer. SIGMA has a 3-unit CubeSat, and the weight is about 3.2 kg. The main payload is TEPC which can measure the Linear Energy Transfer (LET) spectrum and calculate the equivalent dose for the complicated radiation field in the space. The magnetometer is a secondary payload using a miniaturized fluxgate magnetometer. We expect it to have a 1 nT resolution in the dynamic range of ${\pm}65535$ nT. An Attitude Control System (ACS) spins the SIGMA spacecraft 4 rpm with the spin axis perpendicular to the ecliptic plane. Full duplex communication is consists of VHF uplink and S-band and UHF downlink. In this paper, we introduce the system design and the scientific purpose of the SIGMA CubeSat mission.

• Journal of Navigation and Port Research
• /
• v.36 no.3
• /
• pp.181-187
• /
• 2012

Highly plastic clays in their normally consolidated states are not always linear but are concave downwards. Thus their compression index deceases with the increase of consolidation pressure. The $e-{\log}{\sigma}_{\upsilon}{\prime}$ curves of plastic or non-plastic silty clays are not linear but are convex upwards. In this paper, consolidation tests were conducted with several undisturbed field soils of Korea south coast and their $e-{\log}{\sigma}_{\upsilon}{\prime}$ plots are not always linear. In case of using Butterfield's method(liquid limit 50~100%), ${\ln}{\upsilon}-{\ln}{\sigma}_{\upsilon}{\prime}$ plots are linear. But some undisturbed samples which have void ratio over 2.24, liquid limit over 100% and plasticity index over 60% are not linear. In results of consolidation tests with remolded samples which contain silt(fly ash) contents of 90% has compression index increasing with the increase in consolidation pressure.