• Journal of Microbiology and Biotechnology
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• v.21 no.1
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• pp.28-36
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• 2011

Diblock copolymers composed of poly(${\varepsilon}$-caprolactone) (PCL) and poly(N,N-dimethylamino-2-ethyl methacrylate) (PDMAEMA), or methoxy polyethylene glycol(PEG), were synthesized via a combination of ring-opening polymerization and atom-transfer radical polymerization in order to prepare polymeric nanoparticles as an antifungal drug carrier. Amphotericin B (AmB), a natural antibiotic, was incorporated into the polymeric nanoparticles. The physical properties of AmB-incorporated polymeric nanoparticles with PCL-b-PDMAEMA and PCL-b-PEG were studied in relation to morphology and particle size. In the aggregation state study, AmB-incorporated PCL-b- PDMAEMA nanoparticles exhibited a monomeric state pattern of free AmB, whereas AmB-incorporated PCL-b- PEG nanoparticles displayed an aggregated pattern. In in vitro hemolysis tests with human red blood cells, AmBincorporated PCL-b-PDMAEMA nanoparticles were seen to be 10 times less cytotoxic than free AmB (5 ${\mu}g$/ml). In addition, an improved antifungal activity of AmBincorporated polymeric nanoparticles was observed through antifungal activity tests using Candida albicans, whereas polymeric nanoparticles themselves were seen not to affect activity. Finally, in vitro AmB release studies were conducted, proving the potential of AmB-incorporated PCL-b-PDMAEMA nanoparticles as a new formulation candidate for AmB.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.15 no.6
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• pp.116-126
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• 2016

In this study, lane-wise traffic flow characteristics were analysed on uninterrupted flow using a new notion of "lane-wise travel speed reversal (LTSR)" which is defined as a phenomena that travel speed in the median lane is lower than other lanes. Mathematical formulation was also proposed to calculate the strength of LTSR. The experiment road site is Seoul Outer Ring Expressway (Jayuro-IC~Jangsoo-IC), and travel trajectories for each four lane were collected for weekdays (Mon. through Fri.) during morning peak. Comparing lane-wise travel speeds for entire test road section, no LTSR was observed, meaning that the travel speed in the median lane is the fastest, followed by 2nd, 3rd, and 4th lane as in order. Howerver, the result of microscopic analysis using 100-meter discrete road section based data shows that LTSR occurs many times. Especially the strength of LTSR is higher in congestion area and freeway merge and diverge segment. It is expected that these results could be used as a fundamental data when establishing lane-by-lane traffic operation strategy and developing lane-wise traffic information collection and dissemination technology.

• Journal of electromagnetic engineering and science
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• v.16 no.3
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• pp.169-181
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• 2016

This work presents a new method for enhancing the performance of a dual band Planer Inverted-F Antenna (PIFA) and its lumped equivalent circuit formulation. The performance of a PIFA in terms of return loss, bandwidth, gain, and efficiency is improved with the addition of the proposed open stub in the radiating element of the PIFA without disturbing the operating resonance frequencies of the antenna. In specific cases, various simulated and fabricated PIFA models illustrate that the return loss, bandwidth, gain, and efficiency values of antennas with longer optimum open stub lengths can be enhanced up to 4.6 dB, 17%, 1.8 dBi, and 12.4% respectively, when compared with models that do not have open stubs. The proposed open stub is small and does not interfere with the surrounding active modules; therefore, this method is extremely attractive from a practical implementation point of view. The second presented work is a simple procedure for the development of a lumped equivalent circuit model of a dual band PIFA using the rational approximation of its frequency domain response. In this method, the PIFA's measured frequency response is approximated to a rational function using a vector fitting technique and then electrical circuit parameters are extracted from it. The measured results show good agreement with the electrical circuit results. A correlation study between circuit elements and physical open stub lengths in various antenna models is also discussed in detail; this information could be useful for the enhancement of the performance of a PIFA as well as for its systematic design. The computed radiated power obtained using the electrical model is in agreement with the radiated power results obtained through the full wave electromagnetic simulations of the antenna models. The presented approach offers the advantage of saving computation time for full wave EM simulations. In addition, the electrical circuit depicting almost perfect characteristics for return loss and radiated power can be shared with antenna users without sharing the actual antenna structure in cases involving confidentiality limitations.

• Journal of Soil and Groundwater Environment
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• v.10 no.5
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• pp.52-60
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• 2005

The conceptual model of under-sampled study area will include a great amount of uncertainty. In this study, we investigate the applicability of Markov chain model in a spatial domain as a tool for minimizing the uncertainty arose from the lack of data. A new formulation is developed to generalize the previous two-dimensional coupled Markov chain model, which has more versatility to fit any computational sequence. Furthermore, the computational algorithm is improved to utilize more conditioning information and reduce the artifacts, such as the artificial parcel inclination, caused by sequential computation. A generalized 20 coupled Markov chain (GCMC) is tested through applying a hypothetical soil map to evaluate the appropriateness as a substituting model for conventional geostatistical models. Comparing to sequential indicator model (SIS), the simulation results from GCMC shows lower entropy at the boundaries of indicators which is closer to real soil maps. For under-sampled indicators, however, GCMC under-estimates the presence of the indicators, which is a common aspect of all other geostatistical models. To improve this under-estimation, further study on data fusion (or assimilation) inclusion in the GCMC is required.

• Microbiology and Biotechnology Letters
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• v.47 no.4
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• pp.603-613
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• 2019

This study was carried out to examine the antagonistic effect against phytopathogenic fungi of isolated strains from soil samples collected from Busan, Changwon, and Jeju Island: Botrytis cinerea, Colletotrichum acutatum, Corynespora cassiicola, Fusarium sp., Rhizoctonia solani, Phytophthora capsici, and Sclerotinia sclerotiorum. According to results of our studies, isolated strains showed an antagonistic effect against phytopathogenic fungi. Such an antagonistic effect against phytopathogenic fungi is seen due to the production of siderophores, antibiotic substances, and extracellular amylase, cellulase, protease, and xylanase enzyme activities. Extracellular enzymes produced by isolated strains were significant, given that they inhibited the growth of phytopathogenic fungi by causing bacteriolysis of the cell wall of plant pathogenic fungi. This is essential to break down the cell wall of plant pathogenic fungi and thus help plant growth by converting macromolecules, which cannot be used by the plant for growth, into small molecules. In addition, they are putative candidates as biological agents to promote plant growth and inhibit growth of phytopathogenic fungi through nitrogen fixation, indole-3-acetic acid production, siderophore production, and extracellular enzyme activity. Therefore, this study suggests the possibility of using Bacillus subtilis ANGa5, Bacillus aerius ANGa25, and Bacillus methylotrophicus ANGa27 as new biological agents, and it is considered that further studies are necessary to prove their effect as novel biological agents by standardization of formulation and optimization of selected effective microorganisms, determination of their preservation period, and crop cultivation tests.

• The Korean Journal of Pesticide Science
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• v.20 no.3
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• pp.181-188
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• 2016

BtPlus is a group of biopesticides that are made of Bacillus thuringiensis and immunosuppressant. A new BtPlus that exhibits high insecticidal activity against mosquito larvae has been investigated in control efficacy in field conditions and its environmental safety against aquatic system. This study assessed the control efficacy of BtPlus against mosquito larvae with two different application methods. In aerial spraying application (100 mL per $3.3m^2$), BtPlus was effective at 50% or above formulation concentrations to control mosquito larvae. For a direct application to aqueous mosquito habitat, a semi-field mimicking paddy rice field was constructed. In this condition, BtPlus showed 80% and 100% control efficacies at 0.1% and 0.2% concentrations, respectively. BtPlus also showed 40% mortality against adults at 0.1% concentration in 10% sugar bait. However, its control efficacies against adults were much less than against larvae. Safety assessment of BtPlus against ecosystem was evaluated using young carp (Cyprinus carpio), a water flea (Daphnia magna), and a honey bee (Apis mellifera). BtPlus did not give any adverse effects on these nontarget organisms. Based on these results, BtPlus can be applied to control mosquitoes by direct aqueous application to paddy rice field.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.1
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• pp.9-13
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• 2016

Micelles, which are called solubilization formulation, have been widely used in skin lotion, mist or various formulations for the purpose of solubilizing the fragrance rather than the role of the active ingredient carrier because the particles are very small. In this study, we developed the swollen micelle having a transparent appearance to deliver ${\beta}$-sitosterol. When preparing the swollen micelle, solubility parameter was considered with active ingredient. This method allowed insoluble active ingredient to be safely entrapped inside the micelles. Stability of micelle was evaluated by dynamic light scattering (DLS). The transparency and shape of the micelles were confirmed by cryo-TEM. In addition, through the thermal analysis using DSC, ${\beta}$-sitosterol was found to be stably present in the swollen micelles. These results indicate that swollen micelles considered solubility parameter could be used as a new carrier for the insoluble active ingredients.

• Polymer(Korea)
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• v.34 no.5
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• pp.459-463
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• 2010

Amphotericin B (AmB) is anti-fungal agent for the treatment of systemic fungal infections, but its poor solubility has limited clinical applications. In this study, a new gel formulation made up of L-arginine as solubilizer, thermosensitive Poloxamer 407 (P 407), and adhesive carbopol was designed for effective solubilization and delivery of AmB. The aqueous solubility of AmB was enhanced up to 2.6 mg/mL by addition of L-arginine. Aqueous P 407 solutions of more than 20% w/v showed thermo-induced sol-gel-sol phase transition. The phase transition behavior was affected by the presence of AmB and L-arginine, and the phase transition range was broadened by addition of carbopol. In vitro drug release was improved by the solubilizing effect of L-arginine, and the presence of mucoadhesive carbopol prolonged the release rate as a function of concentration.

• Journal of Periodontal and Implant Science
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• v.34 no.1
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• pp.195-204
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• 2004

A novel glucanhydrolase from Lipomyces starkeyi KSM 22 has been suggested as a promising anti-plaque agent because it has been shown to have additional amylase activity and mutanase activity besides dextranase activity and to strongly bind to hydroxyapatite. Mouthrinsing with Lipomyces starkeyi KSM 22 glucanhydrolase solution was comparable to 0.12% chlorhexidine mouthwash in inhibition of plaque accumulation and gingival inflammation and local side effects were less frequent and less intense in human experimental gingivitis. In this study, Lipomyces starkeyi KSM 22 glucanhydrolase mouthrinses (1 and 2 unit/ml) were compared with a control mouthrinse (commercial 0.01% benzethonium chloride mouthrinse, $Caregargle^{(R)}$, Hanmi Pharmaceuticals) in the ability to inhibit plaque formation. A 3-replicate clinical trial using 4-day plaque regrowth model was used. Fifteen volunteers were rendered plaque-free on the 1st day of each study period, ceased toothcleansing, and rinsed 2X daily with allocated mouthrinse thereafter. On day 5, plaque accumulation was scored and the washout periods was 9 days for the next trial. Lipomyces starkeyi KSM22 glucanhydrolase(1 unit and 2 unit)- containing mouthrinse resulted in Significantly lower plaque formation in plaque area and thickness, compared to the control mouthrinse. There was no significant difference in plaque inhibition between enzyme-mouthrinses at 2 different concentrations used. This glucanhydrolase- containing mouthwash resulted in significantly lower plaque area severity index score and tended to have lower plaque thickness severity index score than those of control mouthrinse. But there was no significant difference according to the enzyme concentration. From these results, Lipomyces starkeyi KSM 22 glucanhydrolase-containing benzethonium chloride mouthrinse has greater anti-plaque effect than the commercial mouthrinse alone. Therefore this glucanhydrolase preparation is a promising agent for new mouthwash formulation in the near future.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.12 no.10
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• pp.4678-4702
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• 2018

Traffic Matrix estimation has always caught attention from researchers for better network management and future planning. With the advent of high traffic loads due to Cloud Computing platforms and Software Defined Networking based tunable routing and traffic management algorithms on the Internet, it is more necessary as ever to be able to predict current and future traffic volumes on the network. For large networks such origin-destination traffic prediction problem takes the form of a large under- constrained and under-determined system of equations with a dynamic measurement matrix. Previously, the researchers had relied on the assumption that the measurement (routing) matrix is stationary due to which the schemes are not suitable for modern software defined networks. In this work, we present our Compressed Sensing with Dynamic Model Estimation (CS-DME) architecture suitable for modern software defined networks. Our main contributions are: (1) we formulate an approach in which measurement matrix in the compressed sensing scheme can be accurately and dynamically estimated through a reformulation of the problem based on traffic demands. (2) We show that the problem formulation using a dynamic measurement matrix based on instantaneous traffic demands may be used instead of a stationary binary routing matrix which is more suitable to modern Software Defined Networks that are constantly evolving in terms of routing by inspection of its Eigen Spectrum using two real world datasets. (3) We also show that linking this compressed measurement matrix dynamically with the measured parameters can lead to acceptable estimation of Origin Destination (OD) Traffic flows with marginally poor results with other state-of-art schemes relying on fixed measurement matrices. (4) Furthermore, using this compressed reformulated problem, a new strategy for selection of vantage points for most efficient traffic matrix estimation is also presented through a secondary compression technique based on subset of link measurements. Experimental evaluation of proposed technique using real world datasets Abilene and GEANT shows that the technique is practical to be used in modern software defined networks. Further, the performance of the scheme is compared with recent state of the art techniques proposed in research literature.