• 대한수학회보
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• 제53권5호
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• pp.1585-1596
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• 2016

In this paper we investigate the existence of nontrivial solutions for the following fractional boundary value problem (FBVP) $$\{_tD_T^{\alpha}(_0D_t^{\alpha}u(t))={\nabla}W(t,u(t)),\;t{\in}[0,T],\\u(0)=u(T)=0,$$ where ${\alpha}{\in}(1/2,1)$, $u{\in}{\mathbb{R}}^n$, $W{\in}C^1([0,T]{\times}{\mathbb{R}}^n,{\mathbb{R}})$ and ${\nabla}W(t,u)$ is the gradient of W(t, u) at u. The novelty of this paper is that, when the nonlinearity W(t, u) involves a combination of superquadratic and subquadratic terms, under some suitable assumptions we show that (FBVP) possesses at least two nontrivial solutions. Recent results in the literature are generalized and significantly improved.

• 한국융합학회논문지
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• 제3권4호
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• pp.1-5
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• 2012

최근 IT기술의 발전에 따라 언제 어디서나 이용할 수 있는 U-Healthcare분야의 기술 개발이 빠르게 진행되고 있다. U-Healthcare 기술은 네트워크를 기반으로 하기 때문에 다양한 보안의 위협요소가 발생된다. 본 논문에서는 네트워크 공격 기반의 DOS/DDOS공격에 대한 위협을 알아보고, 기존 Detecting Early DOS/DDOS attacks through Packet Counting을 수정하여 U-Healthcare서비스 상황에 맞는 대응 기법을 제안한다.

• KSBB Journal
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• 제14권6호
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• pp.707-712
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• 1999

Dextransucrse와 ${\alpha}$-amylase의 혼합효소반응 통하여 새로운 구조의 올리고당을 생산하였고, 그 특성을 조사하였다. 기질인 설탕과 녹말의 농도를 10%(w/v), 5%(w/v)로 하였을 때 dextransucrase와 ${\alpha}$-amylase의 활성비가 100U대 1000U일 경우 올리고당의 종류와 생산수율이 66.4%로 가장 높았다. 녹말의 분해산물이 dextransucrase의 수용체 반응을 활성화시켜 dextransucrase 활성을 증가시켰다. 혼합효소의 활성이 증가할수록 올리고당보다는 다당을 생산하였다. 5%(w/v)의 녹말을 1시간동안 반응시켜 수용체로 이용될 수 있는 산물의 양을 증가시킨 후 설탕의 농도가 10%(w/v)가 되도록 반응시킨 방법이 녹말과 설탕을 반응초기부터 모두 반응시킨 방법보다 올리고당 생산수율이 12% 더 증가하였다. 새로운 구조의 올리고당은 pH 3에서는 10.6, pH 4에서는 7.8%의 분해를 보였다. 새로운 구조의 올리고당은 pH 6과 140$^{\circ}C$ 고온에서 89.3%까지 안정하였다.

• 대기
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• 제21권3호
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• pp.319-336
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• 2011

The objective of this study was to assess the meteorological capability of Korea by comparing with that of the U.S. and Japan as of 2010. The research was conducted based on various indices and surveys, and quantified the results using the Gordon's scoring model. The index assessment used 11 items derived from 9 segments - surface observation, advanced observation and observations quality in the observation field; data assimilation, numerical model and infrastructure in the data processing field; forecast accuracy in the forecast field; climate prediction and climate change in the climate field - in this research, we classified the meteorological technology into four fields. In the survey assessment, another 10 items in addition to the above 11 ones (total 21 items) were used. In the field of climate, Korea was found to lag far behind the U.S. (96.5p) and Japan (90.5p) with 77.6 points out of 100, which is 18.9 and 12.9 points lower than them respectively. On the other hand, Korea showed the narrowest gap with Japan (95.3p) and the U.S. (94.2) in the forecasting field, recording 90.3 points. Particularly, in surface observation, infrastructure and forecast accuracy segment, Korea was on a par with the U.S. and Japan, boasting 100.5 percent compared to their counterparts. However, in advanced observation, data quality and climate change segment, Korea was only at the level of 81.5 percent compared to that of the U.S. and Japan. All in all, the technological prowess of Korea, scoring 84.6 points, stood at 89.7 percent of that of the U.S. (94.3p) and 91.9 percent of Japan (92.1p).

• Restorative Dentistry and Endodontics
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• 제26권2호
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• pp.162-170
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• 2001

The purpose of this study was to investigate the effect of cavity configurations on the marginal leakage of class 5 glass ionomer cement and composite resin restorations. Four types of cavities such as saucer shape. notch shape. combined shape(notch shape occlusally and saucer shape gingivally). and U shape were prepared on the buccal and lingual surfaces of 80 extracted premolars(40 cavities for each shape). Occlusal cavity margins were placed at enamel and cervical margins were placed at dentin. 10 cavities of each shape were restored with Ketac Fil as a conventional glass ionomer cement. Fuji II LC improved as a resin modified glass ionomer cement, Z 100 as a hybrid composite resin. and Tetric Flow as a flowable composite resin (40 cavities for each material). After thermocycling, teeth were immersed in 5% basic fuchsin solution for 6 hours and sectioned longitudinally in a buccolingual direction through the center of the restoration. The dye penetrations at the tooth restoration interface were examined by stereomicroscope. The Result were as follows 1. In saucer shape, notch shape and combined shape, composite resin restorations showed lesser leakage than glass ionomer restorations(p<0.05) and in U shape. Tetric Flow showed the least marginal leakage and others were decreased as Z 100. Fuji II LC improved, Ketac Fil in that order. There were statistically significant difference between Tetric Flow and Fuji II LC improved. Ketac Fil and between Z 100 and Ketac Fil(p<0.05). 2. In Ketac Fil restoration group, saucer shape showed the highest marginal leakage and U shape showed the least marginal leakage and others were decreased as notch shape, combined shape in that order. There were statistically significant difference between saucer shape and combined shape, U shape and between notch shape and U shape(p<0.05). 3. In Fuji II LC improved restoration group, U shape showed the least marginal leakage. There were statistically significant difference between U shape and other three shapes(p<0.05). 4. The cavity configuration had no significant effect on marginal leakage of composite resin restorations(p>0.05).

• Nuclear Engineering and Technology
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• 제49권3호
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• pp.645-650
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• 2017

This technical note demonstrates the feasibility of using laser ablation inductively coupled plasma mass spectrometry for the characterization of U-7Mo/Ale5Si dispersion fuel. Our measurements show 5.0% Relative Standard Deviation (RSD) for the reproducibility of measured $^{98}Mo/^{238}U$ ratios in fuel particles from spot analysis, and 3.4% RSD for $^{98}Mo/^{238}U$ ratios in a NIST-SRM 612 glass standard. Line scanning allows for the distinction of U-7Mo fuel particles from the Al-5Si matrix. Each mass spectrum peak indicates the presence of U-7Mo fuel particles, and the time width of each peak corresponds to the size of that fuel particle. The size of the fuel particles is estimated from the time width of the mass spectrum peak for $^{98}Mo$ by considering the scan rate used during the line scan. This preliminary application clearly demonstrates that laser ablation inductively coupled plasma mass spectrometry can directly identify isotope ratios and sizes of the fuel particles in U-Mo/Al dispersion fuel. Once optimized further, this instrument will be a powerful tool for investigating irradiated dispersion fuels in terms of fission product distributions in fuel matrices, and the changes in fuel particle size or shape after irradiation.

• 한국가축번식학회지
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• 제5권2호
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• pp.56-59
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• 1981

The sows which had not returned estrus since 15 to 152 days after weaning were treated with PMSG or PGF2$\alpha$ to induce estrus and inseminated to conceive on that estrus. 1. Eight (83%) among 12 sows treated with PMSG came into estrus on average 5.3 days after treatment. 2. The one sow which didn't show any estrus by treatment of PMSG showed an estrus by intramuscular use of 10mg PGF2$\alpha$ and the other one showed an estrus by another intramuscular use of 1000 I.U. of PMSG at 15 days after first injection of PMSG. 3. The one sow injected with Vit. A.D.E. complex(Injacom) (Vit. A 500,000 I.U., Vit. D. 75,000 I.U., and Vit. E. 50 I.U. per ml) on 6 days before PMSG injection showed an estrus on 6 days after PMSG injection and farrowed 8 piglets. 4. Five among 10 sows showed an estrus by treatment of PMSG or PGF2$\alpha$ were pregnant and litter size of the four farrowed sows averaged 9.5.

• Journal of Microbiology and Biotechnology
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• 제20권7호
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• pp.1101-1106
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• 2010

Pulsed electric field (PEF) of 1Hz, 1.5 kV, and 1ms increased the activities of catalase and inulinase over the whole range of applied Se concentrations compared with the non-treated cultures. A significant effect of selenium concentration (in the range of 5-14 ${\mu}g/ml$) on both intra- and extracellular enzyme activities was noted. At a Se concentration of 10 ${\mu}g/ml$, the activities of intra- and extracellular inulinases and extracellular catalase in the PEF-treated cultures reached the maximum of 71 U/g d.m., 46 U/g d.m., and approx. 8 U/ml, respectively. The maximum activity of intracellular catalase of approx. 6 U/ml (with and without PEF) was recorded at 5 ${\mu}g$ Se/ml. Further increasing of selenium concentration caused a decrease in the activity of the enzymes.

• 한국식품위생안전성학회지
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• 제11권1호
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• pp.7-10
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• 1996

Chicken skins or carcasses inoculated with Salmonella typhimurium were exposed to 0.1 or 0.5% grapefruit seed extracts (DF-100) for 1 or 3 min to evaluate antibacterial activity of DF-100 and its possible application in proultry processing. The numbers of live salmonellae on chicken skins were reduced by 0.8-1.2 logs/cm2 with 0.5% DF-100. Dipping chicken carcasses into 0.5% DF-100 for 3 min reduced salmonelae by 4.3 logs/carcass. Scanning electron microscopy showed that DF-100 killed the cells attached but did not detach cells from the skin. No odor or changes in the color of chicken skin were detected after DF-100 treatment.

• 대한수학회보
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• 제52권5호
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• pp.1517-1533
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• 2015

In this paper, we prove the existence of at least three nontrivial solutions to nonlinear discrete boundary value problems $$\{^{-{\Delta}_{p,{\omega}}u(x)+V(x){\mid}u(x){\mid}^{q-2}u(x)=f(x,u(x)),x{\in}S,}_{u(x)=0,\;x{\in}{\partial}S}$$, involving the discrete p-Laplacian on simple, nite and connected graphs $\bar{S}(S{\cup}{\partial}S,E)$ with weight ${\omega}$, where 1 < q < p < ${\infty}$. The approach is based on a suitable combine of variational and truncations methods.