• Korean Journal of Mathematics
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• 제24권2호
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• pp.297-305
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• 2016

In this paper, by using fixed point theorem, we obtain the stability of the following functional equations $$f(pr,qs)+g(ps,qr)={\theta}(p,q,r,s)f(p,q)h(r,s)\\f(pr,qs)+g(ps,qr)={\theta}(p,q,r,s)g(p,q)h(r,s)$$, where G is a commutative semigroup, ${\theta}:G^4{\rightarrow}{\mathbb{R}}_k$ a function and f, g, h are functionals on $G^2$.

• 한국지하수토양환경학회지:지하수토양환경
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• 제28권1호
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• pp.15-24
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• 2023

A persulfate(PS)/sulfidated microscale zero-valent iron(S-mZVI) system was tested for treating a soil contaminated with phenol. Sulfidation of bare mZVI was conducted using a mechanochemical process utilizing a ball mill in order to improve persulfate activation capacity and stability of unmodified mZVI. The synthesized S-mZVI performed markedly better than the bare mZVI in activating PS. The optimum molar ratio of sulfur to mZVI was around 0.12. In the soil slurry experiments, a very rapid and complete removal of phenol was observed at the optimum molar ratios of PS to S-mZVI of 2:1 and PS to phenol of 16:1. The phenol removal efficiencies decreased as the water content of the slurries decreased. This was believed to be due to increased soil oxidant demand as the amount of soil was increased as relative to the water content. To evaluate the field applicability of the process, slurry experiments adopting high soil contents were carried out that simulated in-situ soil mixing conditions. These experiments resulted in substantially compromised degradation efficiencies of 54.3% and 43.8% within 4 hours. The current study generally shows that the PS/S-mZVI process has a potential to be developed into a remediation technology for soils contaminated with organics.

• 국제물리치료학회지
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• 제1권1호
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• pp.58-64
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• 2010

The purpose of this study was to investigate the distribution of trigger points(TrPs) on athletes with various sporting background. To achieve the purpose, a study was carried out through a survey from 180 athletes involved in 6 selected sports at Yong-In University. Selected sports included Judo, Taekwondo, Kendo, Ssi-reum(Korean traditional wrestling), Boxing, and Golf. An interview type survey and physical examination were conducted with each thirty athletes from each of the selected sports groups. Technical statistic(SPSS 15.0) was used to analyze the distribution of TrPs on these athletes. The most common TrPs observed in muscles of Trapezius, Quadratus Lumborum, Quadriceps in Judo. In Taekwondo, it was on the trapezius and triceps surae. Kendo athletes had TrPs at sites of trapezius, brachioradialis and triceps surae. Ssirem athletes were found to have TrPs on trapezius, deltoid and quadrates lumborum. In boxers, TrPs appearing at trapezius and brachioradialis were observed. Finally, Golf players were seen to have TrPs at trapezius, quadrates lumborum and brachioradialis. Hence, the analysis shows that there are significant differences of the distribution of TrPs according to the different sport items of the athlete.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 하계학술대회 논문집
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• pp.223-223
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• 2009

In this paper, designed and simulated Power Splitter (PS) integrated Mach-Zehnder interferometer (MZI) based planar type optical waveguide devices (which is called here a PS-MZI). The PS-MZI optical waveguide sensor was preceded by a Y-junction, which splits the input power between the sensor, and a reference branch, to minimize the effect of optical power variations. The PS-MZI optical waveguide sensor induced changing phases of the incident beam, which had fallen upon the waveguide through computer simulation, according to the small changes in the index of refraction, thus beam intensity was changed. The waveguide were optimized at a wavelength of 1550 nm and fabricated according to the design rule of 0.45 delta%, which is the difference of refractive index between the core and clad. The fabrication of PS-MZI optical waveguide sensor was performed by a conventional planar lightwave circuit (PLC) fabrication process. The PS-MZI optical waveguide that was fabricated to be applied as a biosensor revealed a low insertion loss and a low polarization-dependent loss. After having etched the over-clad at the sensor part in the MZI optical waveguide that was fabricated, Ti deposition was made on the adhesion layer, and then Au thin-film deposition was carried out thereon. In addition, its optical properties were measured by having changed the index of refraction oil at the sensing part of the MZI. To apply the planar type PS-MZI optical waveguide as a biosensor, a detection test for Staphylococcus aureus was conducted according to changes in concentration, having adopted Ti-alkoxide as ligand. The detection result of the S. aureus by the PS-MZI optical waveguide sensor was possible to the level of $10^1$ CFU/ml.

• Journal of Korean Neurosurgical Society
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• 제63권6호
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• pp.784-793
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• 2020

Objective : We attempted to compare the incidence of pyogenic spondylitis (PS) and tuberculous spondylitis (TS) between 2007 and 2016. Furthermore, we investigated the patients who underwent surgery in 2016 compared to that in 2007. Methods : We used a nationwide database managed by the Korean National Health Insurance Service (NHIS) in 2007 and 2016. Total 9655 patients with a newly diagnosis of PS or TS were enrolled in PS or TS group. Among them, 1721 patients underwent either fusion or decompression surgery. We analyzed demographic distribution of patients according to gender and age and year of diagnosis. Results : Comparing between 2007 and 2016, the incidence of PS has increased in 2016 than in 2007 (4874 vs. 2431, p<0.0001). Conversely, declination of incidence of TS was discovered in 2016 compared to 2007 (594 vs. 1756, p<0.0001). Females showed predominance over males regarding both PS and TS (5228 vs. 4427, p<0.0001). Among them, the number of PS patients who underwent surgery increased significantly in 2016 relative to that in 2007 (979 vs. 592, p<0.0001). Conclusion : This nationwide study suggests that PS may increase and TS may decrease in Korea. In addition, demand for surgery regarding PS may increase.

• 동의생리병리학회지
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• 제23권3호
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• pp.599-607
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• 2009

Prunellae Spica is the spike or whole plant of Prunella vulgaris Linne, which has been used for clearing heat from the liver, brightening the eyes and treating headache in traditional oriental medicines. This study was conducted to evaluate the inhibitory effects of the aqueous extract of Prunellae Spica (PSE; PS extract) on the production of NO and PGE2 in LPS-activated Raw 264.7 cells. Cell viability was determined by MTT assay, and all three doses of PS extract (0.03, 0.1 and 0.3 mg/ml) had no significant cytotoxicity during the entire experimental period. The cells were treated with 1 ${\mu}g/ml$ of LPS 1 h before adding PS extract, and increased NO and PGE2 production were detected in LPS-activated cells compared to control. However, these increases were dose-dependently attenuated by treatment with PS extract. The inhibition of NO by PS extract was due to the suppression of iNOS expression via inhibition of $NF{\kappa}B$ nuclear translocation and proteolytic degradation of $I{\kappa}B{\alpha}$. The decreased level of PGE2 was derived from inhibition of COX-2 activity, but expression of COX-2 protein was not affected by PS extract. Moreover, PS extract reduced the elevated production of IL-${\beta}$ and IL-6 by LPS. These results demonstrate that PS extract has inhibitory effects on the production of NO and PGE2 as a consequence of the reduction of proinflammatory cytokines, especially IL-${\beta}$ and IL-6 in LPS-activated Raw 264.7 cells.

• Journal of the Optical Society of Korea
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• 제10권3호
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• pp.112-117
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• 2006

We experimentally investigated the transmission characteristics of 400 Gbit/s (10 Gbit/s ${\times}$ 40 channels) WDM signals with 100 GHz channel spacing over 323 km of installed NZ_DSF. The installed fiber has optical properties of 0.28 dB/km attenuation, 4.3 ps/nm/km dispersion, $0.083ps/nm^2/km$ dispersion slope and less than $0.05ps/km^{1/2}$ PMD coefficient. In this experiment, two cases of dispersion compensation schemes, the lumped type and the distributed type, were compared. The results implied that the distributed type dispersion compensation in which dispersion compensation devices are inserted at the end of the each span showed better transmission performance than the lumped one in which dispersion compensation devices are located at the transmitter and receiver sites. From the analysis of the experimental results, we verified that different transmission performance comes from the power penalty induced by XPM in the distributed scheme is lower than the lumped scheme case.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 C
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• pp.1173-1176
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• 1999

전력계통에서 발생하는 저주파 동요에 대해서 가장 효과적인 제동력 향상방안으로 알려진 PSS의 최적 설치지점을 결정하기 위하여 NSE(Normalizing Speed Eigenvectors), SPF(Speed Participation Factors), TFR(Transfer Function Residues) 및 주파수 응답법을 각각 비교분석 하였다. 분석결과 SPF는 제어/입력 행렬을 포함하지 않는 상태행렬만을 고려하기 때문에 PSS의 제어특성을 반영하지 못하는 단점이 있었으며 TFR은 여자기 이득에 민감하여 최적위치 선정에 있어서 문제점을 보였다. 본 연구에서는 SPF법을 이용하여 PSS 설치 후보지를 선정하고 이들 후보지에 대해서 TFR법과 주파수 응답법으로 최적의 발전기를 결정하도록 하였으며 PSS를 설치하여 그 효과를 검증하였다.

• Bulletin of the Korean Chemical Society
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• 제18권2호
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• pp.156-161
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• 1997

Aqueous 6-hydroxyquinoline in the first excited singlet state undergoes protonation to the imine group first in 15 ps, then in the time scale of 40 ps deprotonation from the enol group and finally, however, quickly as in 11 ps electron rearrangement to change into a resonance hybrid structure of quinoid-prevailing forms. Despite the fact that the decay time constant is smaller than the formation time constant, fluorescence from excited protropic zwitterion is observed to assign its maximum at 510 nm. The electron rearrangement is basically an intramolecular charge transfer from the deprotonated oxygen atom to the positively charged iminium ring without any notable change in nuclear geometry, producing a zwitterionic quinoid structure with much a smaller electric dipole moment than the zwitterionic protropic species. This photoproduct formed by consecutive excited state proton and electron transfers shows a smaller dipole moment in S1 than in S0 and a hypsochromic shift although its S1 state has (π, π*) character.

• Asian-Australasian Journal of Animal Sciences
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• 제9권3호
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• pp.319-329
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• 1996

During the monsoon in Bangladesh, the possibility of preserving wet ($700g\;H_2O$) straw by urea (50 g/kg straw DM) with or without polythene cover has been studied. The quality of preserved straw (PS) in terms of colour, smell and fungal infestation were recorded. Nutritive value of the PS was compared to that of a dry straw (DS) in two separate feeding trials on growing bulls (about 290 kg) without (Expt. 1) or with (Expt. 2) concentrate supplements. Over 96% of the wet straw was excellently preserved for over 5 months when covered with polythene in horizontal heaps (of appx. 4 tons). Whereas only 33% of the straw was well preserved in the uncovered (dome shaped) heaps (of approximately 9.5 tons). Each ton of wet straw costed Tk. 1413 and its preservation cost incurred Tk. 345. Urea preservation increased the crude protein content (95 vs. 50 g/kg), dry matter (DM) degradability at all (8, 16, 24, 48, 72 and 96) hours of incubation and at 48 hours, DM degradability (%) were 45 and 25 respetively for the PS and the DS. When fed alone, DM intake (75 vs. $106g/kg\;W^{0.75}/d$), total microbial N yield (27 vs. 54 g/d) and growth rate (-379 vs. 283 g/d) were higher (p < 0.01) in the PS than the DS. Supplementation of concentrate reduced the straw DM intake both in the DS ($51g/kg\;W^{0.75}/d$) and the PS ($958g/kg\;W^{0.75}/d$), but the substitution rate (SR%) was higher in the PS (42) than the DS (27). Higher substitution rate was probably responsible for the reduction in the differences between the DS and PS in their nutrient digestibilities, total microbial N yield (62 vs. 64 g/d) and growth rate(669 vs 339 g/d) when supplemented with concentrate. On 28th day of Expt. 2, feeding PS from one of the polythene covered heaps resulted nervous disorder due to unknown reason(s). Further studies on the effect of size and shape of heap on the preservation quality need to be determined.