• KSII Transactions on Internet and Information Systems (TIIS)
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• 제8권10호
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• pp.3394-3408
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• 2014

Conventional mobile state (MS) and base station (BS) association based on average signal strength often results in imbalance of cell load which may require more powerful processor at BSs and degrades the perceived transmission rate of MSs. To deal with this problem, a Markov decision process (MDP) for load balancing in a multi-cell system with multi-carriers is formulated. To solve the problem, exploiting Sarsa algorithm of on-line learning type [12], ${\alpha}$-controllable load balancing algorithm is proposed. It is designed to control tradeoff between the cell load deviation of BSs and the perceived transmission rates of MSs. We also propose an ${\varepsilon}$-differential soft greedy policy for on-line learning which is proven to be asymptotically convergent to the optimal greedy policy under some condition. Simulation results verify that the ${\alpha}$-controllable load balancing algorithm controls the behavior of the algorithm depending on the choice of ${\alpha}$. It is shown to be very efficient in balancing cell loads of BSs with low ${\alpha}$.

• The Korean Journal of Physiology and Pharmacology
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• 제13권1호
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• pp.55-59
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• 2009

Three dimensional quantitative structure activity relationship between diazabicyclo[4.2.0]octanes and nicotinic acetylcholine receptor($h{\alpha}4{\beta}2$ and $h{\alpha}3{\beta}4$) agonists was studied using comparative molecular field analysis(CoMFA) and comparative molecular similarity indices analysis(CoMSIA). From 11 CoMFA and CoMSIA models, CoMSIA with steric and electrostatic fields gave the best predictive models($q^2=0.926$ and 0.945, ${r^2}_{ncv}=0.983$ and 0.988). This study can be used to develop potent $h{\alpha}4{\beta}2$ receptor agonists with low activity on $h{\alpha}3{\beta}4$ subtype.

• 미생물학회지
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• 제14권3호
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• pp.135-145
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• 1976

Confluent AGMK cells were infected by large plaque SV40 virus. Levels of DNA polymeras $({\alpha}\;and\;{\beta})$ were measured in the cytoplasm and the cell nucleus. The activities of DNA $polymerase-{\alpha}$ which found in both the cell nucleus and the cytoplasm were increased approximately eight folds at 48 hours after infection of SV40 virus. Only insignificant but constant amounts of DNA $polymerase-{\beta}$ were found either in the nucleus of the SV40 infected cell or of the uninfected cell. The characteristics of the SV40 virus induced DNA polymerases were compared with that of the uninfected cellular DNA polymerase in regard of the effects of pH, salt concentration, NEM concentration and temperature on those enzyme activities. No differential effect was found between both enzymes. Endouclease activities wre examined in the purified DNA $polymerase-{\alpha}\;and\;{\beta}$. The low level of endonuclease activity which might cut SV40 DNA 1 at one site was observed in the DNA $polymerase-{\alpha}$ whereas high but nonspecific endonuclease activities were found in the DNA $polymerase-{\beta}$.

• Journal of Magnetics
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• 제17권2호
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• pp.133-137
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• 2012

We investigated the effects of pulsed magnetic fields (PMF) stimulus on electroencephalogram (EEG) alpha activity and heart rate variability (HRV) from electrocardiogram (ECG) measurements with various stimulus durations at acupoint PC9. The alpha activity in the EEG and the ratio of low frequency power and high frequency power (LHR) in the HRV, a reflection of sympathovagal activity, were increased and decreased, respectively, after PMF stimulus of 3 min. Our spectral analysis quantitatively proved that the changes in the EEG alpha activity were consistent with an autonomic function in the ECG. These findings suggest that appropriate PMF stimulus results in the same effect as that of acupuncture applied to the acupoint PC9, which is closely related to the parasympathetic activity of the autonomic nervous system.

• Journal of Microbiology and Biotechnology
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• 제11권3호
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• pp.389-393
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• 2001

An $\alpha$-glucosidase inhibitor, CK-4416, was identified from the culture broth of Streptomyces sp. CK-4416. CK-4416, which had some specificity against intestinal disaccharidases, especially sucrase and matlase activities, was purified by adsorption and cationic ion exchange chromatographies. The molecular formula was determined to be $C_{37}H_{63}NO_{30}$ (MW 1001.31) by FAB-MS and NMR analyses. In vitro studies found CK-4416 to show a potent inhibitory activity against sucrase and maltase, but it had low inhibition against $\alpha$-amylase.

• 한국세라믹학회지
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• 제29권2호
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• pp.143-151
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• 1992

Partially stabilized alpha-sialon composition (X=0.1) powder was hot-pressed at 1800~200$0^{\circ}C$ for 0~90 min with 30 MPa. Sintering behavior, phase changes and mechanical properties for the specimens were studied. As sintering temperature was raised from 1800 to 190$0^{\circ}C$, the relative density tended to increase and reached 99% of theoretical at 190$0^{\circ}C$. However the amount of alpha-sialon decreased because alpha-sialon transformed to beta-Si3N4 and yttrium rich silicate glass. In the case of hot-pressing at 190$0^{\circ}C$ for various times, densification increased with sintering time and full densification above 99% of theoretical was attained by 30 min. The amount of alpha-sialon decreased with sintering time. The maximum strength of 825 MPa was obtained by hot-pressing at 190$0^{\circ}C$ for 60 min.

• Bulletin of the Korean Chemical Society
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• 제7권5호
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• pp.341-346
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• 1986

The electrical conductivity of the system ${\alpha}-Fe_2O_3-CoO$ was measured in the temperature range 200-1000$^{\circ}C$ and PO$_{2}$ range 10$^{-7}-2{\times}10^{-1}$ atm. Possible defect models were suggested on the basis of conductivity data, which were measured as a function of temperature and of oxygen partial pressure. The observed activation energies were 0.50 eV and 1.01 eV in the low- and high-temperature regions, respectively. The observed conductivity dependences on PO$_{2}$ were ${\sigma}\;{\alpha}\;PO_2^{-1/6}$ in the PO$_{2}$ range $10^{-7}-10^{-4}$ atm and ${\sigma}\;{\alpha}\;PO_2^{-1/4}$ at PO$_{2}$ 's of $10^{-4}-2{\times}10^{-1}$ atm at temperatures from 300-1000$^{\circ}C$. An extrinsic electron conduction due to an Vo defect and an intrinsic electron conduction due to an Fei' defect were suggested at different temperature and oxygen partial pressure regions, respectively.

• 한국항공우주학회지
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• 제34권10호
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• pp.16-23
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• 2006

저 레이놀즈수에서 NACA 0012 에어포일의 경계층 거동에 관한 연구가 터빈 블레이드와 초소형 비행체에서 적용될 수 있는 경계층을 파악하기 위하여 수행되었다. 레이놀즈수 Re=$2.3{\times}10^4$, $3.3{\times}10^4$, $4.8{\times}10^4$과 정적 받음각 ${\alpha}$=$0^{\circ}$, $3^{\circ}$, $6^{\circ}$에서 경계층을 측정하기 위해 열선 풍속계가 사용되었다. 연구결과는 정적 받음각 =$0^{\circ}$에서는 층류 경계층이 에어포일 표면에 부착되며, 정적 받음각 $3^{\circ}$에서는 경계층 층류 분리가 발생된 것을 보여준다. 더욱이 본 연구에서 경계층 재부착 현상은 정적 받음각 $6^{\circ}$에서 레이놀즈수 $3.3{\times}10^4$와 $4.8{\times}10^4$에서 발생된다.

• 대한임상검사과학회지
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• 제43권2호
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• pp.48-56
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• 2011

Gastrointestinal stromal tumor (GIST) is a mesenchymal tumor and is associated with a specific immunophenotype index. It is very important to identify the specific immunophenotype and the diagnosis for the treatment GIST patients. Ninety two cases of GIST analyzed in this study were immuno-stained for c-kit, DOG1, CD34, PKC-${\theta}$, PDGFR-${\alpha}$. The rate of positive staining and statistical significance were then compared. In addition, the GISTs were analyzed as followings: very low risk, low risk, intermediate risk and high risk according to tumor size and nuclear division, and later correlated with clinical parameters. The results of the GIST positive stainings were: DOG1 (95.7%), PKC-${\theta}$ (90.2%), PDGFR-${\alpha}$ (88.0%), c-kit (87.0%) and CD34 (71.7%). Only DOG1 staining showed a statistical significance of p<0.05. It was identified in the classification system of histologic risk that staining expression of DOG1, PKC-${\theta}$, PDGFR-${\alpha}$ were significantly increased as histologic risk increases (p<0.05). However, clinical parameters such as age and sex of patients have no correlations with the classification system of histologic risk (p>0.05). Therefore, in this study, the expression of DOG1 showed statistical significance and DOG1, PKC-${\theta}$, PDGFR-${\alpha}$ staining increased significantly as the histologic risk increases in histologic classification system. Taken together, the DOG1 staining should be very effective for the diagnosis of GIST patients.

• 한국수산과학회지
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• 제46권1호
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• pp.70-76
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• 2013

Some fish live in aquatic environments with low or temporally changing $O_2$ availability. Variation in dissolved oxygen (DO) levels requires behavioral, physiological, and biochemical adaptations to ensure the uptake of sufficient $O_2$. Several species are relatively well adapted to tolerate low $O_2$ partial pressures (hypoxia). The medaka (Oryzias dancena ) is an important model organism for biomedical research that shows remarkable tolerance to hypoxia. We investigated the regulation and role of hypoxia-inducible factor-1 (HIF-$1{\alpha}$) as a general hypoxia-response gene and stanniocalcin-2 (STC2), which is one of the genes regulated by HIF-$1{\alpha}$ in mammals under hypoxia. We subjected adult male medaka to the following three acute hypoxia regimes: 1, 24, and 72 h at DO = $1.8{\pm}0.5$ ppm. The changes in STC2 and HIF-$1{\alpha}$ mRNA were monitored using quantitative real-time reverse-transcription PCR. We found strong upregulation of HIF-$1{\alpha}$ mRNA in the livers of fish exposed to hypoxia. Hypoxia rapidly upregulated STC-2 mRNA expression in muscle, but not in the brain, gills, liver, or intestine. Therefore, unlike in mammals, hypoxia might regulate O. dancena STC-2 expression in an HIF-$1{\alpha}$-independent manner.