• Proceedings of the KOSOMBE Conference
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.19-22
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• 1997

• Proceedings of the PSK Conference
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• 대한약학회 2000년도 NEW STRATEGY FOR DRUG DEVELOPMENT IN POST-GENOMIC ERA(대한약학회)
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• pp.269.1-269.1
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• 2000

• Bulletin of the Korean Mathematical Society
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• 제50권2호
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• pp.353-373
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• 2013

In this paper, a class of delayed predator-prey models of prey migration and predator switching is considered. By analyzing the associated characteristic transcendental equation, its linear stability is investigated and Hopf bifurcation is demonstrated. Some explicit formulae for determining the stability and the direction of the Hopf bifurcation periodic solutions bifurcating from Hopf bifurcations are obtained by using the normal form theory and center manifold theory. Some numerical simulations for justifying the theoretical analysis are also provided. Finally, biological explanations and main conclusions are given.

• YAKHAK HOEJI
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• 제44권3호
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• pp.251-256
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• 2000

Sterically stabilized liposomes (SSL) composed of distearoylphosphatidylcholine, cholesterol, dicetylphosphate and distearoylphosphatiodylethanolamine-N-poly(ethyleneglycol) 2000 (DSPE-PEG 2000) were made by reverse phase evaporation method to prolong biological half-life and decrease toxic side effect of drug. Streptozocin (572), a water-soluble antitumor agent with short half-life, was selected as a model drug. The size of SSL was controlled by polycarbonate extrusion to 100 nm which is adequate size for long circulation in plasma. The release rate of drugs from SSL in PBS was evaluated. And the stability of STZ-containing liposomes against drug leakage into rat plasma was evaluated in order to investigate the interaction of liposome and plasma protein. Incorporation of DSPE-PEG 2000 into conventional liposomes significantly decreased the drug leakage into rat plasma.

• Journal of Biomedical Engineering Research
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• 제12권4호
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• pp.249-254
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• 1991

In the study on the quantitative diagnosis using ultrasound, the stability and precision of tissue characterized parameters are important for the clinical application. We estimate attenuation coefficient introducing homomorphlc process Into the modified spectral differnce method about silicon-madu phantom. We compare the results with those estimated uslng the method used for obtaining the attenuation map image before. Homomorphic process has the effect smoothing the reflected echo signal spectrum, therefore eliminat os the random pattern of the signal spectrum generated by the scatterers. As a result, it Is shown that the stability is enhanced

• Smart Structures and Systems
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• 제30권1호
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• pp.1-15
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• 2022

This article focuses on stability analysis and fuzzy controller synthesis for large neural network (NN) systems consisting of several interconnected subsystems represented by the NN model. Advanced and fuzzy NN differential inclusion (NNDI) for stability based on the developed algorithm with H infinity can be designed based on the evolved biological design. This representation is constructed using sector linearity for NN models. Sector linearity transforms a non-linear model into a linear model based on proposed operations. New sufficient conditions are realized in the form of LMI (linear matrix inequalities) to ensure the asymptotic stability of the trans-Lyapunov function. This transforms the nonlinear model into a linear model based on multiple rules. At last, a numerical case study with simulations is derived as illustration to prove its feasibility in real nonlinear structures.

• Journal of Biomedical Engineering Research
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• 제43권4호
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• pp.251-258
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• 2022

Silk fibroin microparticles were fabricated using a phase separation technique between silk fibroin solution and polyvinyl alcohol. We found that the concentration of polyvinyl alcohol determines the size of microparticles. The mean diameter of the silk fibroin microparticles varied from 3.48 ㎛ to 4.05 ㎛. The silk fibroin microparticle size increased as a function of the concentration of PVA in aqueous silk solution. The resulting silk fibroin microparticles have narrow size distribution (i.e. monodisperse) and smooth/spherical surface. Also, we studied the effects of mouse serum, sodium phosphate buffer (PBS), and pH on the stability of the silk fibroin microparticles. Overall, we demonstrated the simple method to fabricate and to control the silk fibroin microparticles that makes our silk microparticles to be usable for a potential drug delivery carrier.

• Applied Biological Chemistry
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• 제46권1호
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• pp.28-31
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• 2003

Soybean phytosterols have been known to have the effect of reducing the amount of cholesterol in blood. We isolated and analyzed soybean phytosterols from soybean scum. The functional mayonnaise was prepared by the addition of the different amounts of soybean phytosterols. To determine the desirable level of soybean phytosterols in mayonnaise, solubility, viscosity, the stability of emulsion and the sensory evaluation were measured. The most desirable level of soybean phytosterols was 0.5% in solubility, viscosity, stability of emulsion and the sensory evaluation.

• Applied Biological Chemistry
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• 제15권3호
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• pp.207-211
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• 1972

In order to investigate the action of thermophilic fungi on the xylan and its related substances, xylanase and laminaranase were examined using Myriococcum albomyces. In the extract from bran culture of Myriococcum albomyces, xylanase and laminaranase activity were recognized. 1) The optimum pH for xylanase and laminaranase activity were found to be pH 5.0 and pH 6.0. 2) The optimum temperature for xylanase and laminaranase activity were found to be $55^{\cicr}C$. 3) Thermal stability of xylanase for 55 minutes at $65^{\cicr}C$ and laminaranase for 60 minutes at $65^{\cicr}C$ did not influence their stability.

• Journal of the Korean Applied Science and Technology
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• 제19권3호
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• pp.167-173
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• 2002

The isoflavone as a derivatives of flavone is colorless crystalline compounds. It acts on synthesis of fibronectine, collagen III, collagen I in human normal fibroblast by same biological activity to animal hormone. In this study, we tried to search and demonstrate system content rate of dermal translocation system for cosmetics using microemulsion containing isoflavone. The results of microemulsion stability test by centrifugation, storage in incubator and circulation chamber showed that separation of phase did not appear after 30 days. By the skin flexibility test, it has confirmed efficiency and effect as cosmetics materials. As the result, the microemulsion showed that skin flexibility factor improved up to 7.6%. We could confirm that O/W type microemulsion was stable system.