• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2000.11a
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• pp.256-261
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• 2000

Electro-Rheological(ER) fluid is applied to a controllable squeeze film damper(SFD) for stabilizing a flexible rotor system. ER fluid is a class of functional fluid whose yield stress varies according to the applied electric field strength, which is observed as viscosity variation of the fluid. In applying ER fluid to a SFD, a pair of rings of the damper can be used as electrodes. When the electrodes are divided into a horizontal pair and a vertical one, the SFD can produce damping force in each direction independently. A prototype of the directionally controllable SFD was constructed and its performance was experimentally and numerically investigated in the present work.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1102-1108
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• 1997

Proteins and polysaccharides confer distinct functional properties in food systems. This research was attempted to improve emulsion properties of casein by protein-polysaccharide conjugation, in which alginates with various molecular weights were employed as polysaccharide sources. Casein-alginate mixtures were conjugated by the amino-carbonyl or Maillard reaction at 6$0^{\circ}C$ and 79% relative humidity. The resulting casein-alginate conjugates were tested for their emulsion activity and emulsion stabilizing properties. In general, the emulsion stability of casein-alginate mixture greatly increased due to the amino-carbonyl reaction between casein and alginates, whose magnitude depended on the molecular weight of alginate, weight ratio of casein to alginate and incubation time. It was also found that thermal stability and pH stability were markedly improved by the casein-alginate conjugation.

• Bulletin of the Korean Chemical Society
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• v.16 no.7
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• pp.591-594
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• 1995

The influence of protecting groups on the β-sheet-structure-stability of protected peptides was studied in organic solvents. α-amino groups, carboxyl groups and side chain functional groups of model peptides were protected by suitable groups commonly used in peptide synthesis. The difference of the solubilities of model peptides was investigated by the solvent-titration method by using IR absorption spectra. The β-sheet structure of model peptide in CH2Cl2 was easily disrupted by increasing the amounts of DMSO. The β-sheet-structure-stabilizing potentials of each protecting group showed similar behaviors except Npys, Mts and Z2. The result exhibits that the < SPβ > values of protected peptides are almost independent of the kinds of their protecting groups.

• Journal of Microbiology and Biotechnology
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• v.22 no.9
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• pp.1271-1278
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• 2012

Genetic fusion of two proteins frequently induces beneficial effects to the proteins, such as increased solubility, besides the combination of two protein functions. Here, we study the effects of the bacterial surface layer protein SgsE from Geobacillus stearothermophilus NRS 2004/3a on the folding of a C-terminally fused enhanced green fluorescent protein (EGFP) moiety. Although GFPs are generally unable to adopt a functional confirmation in the bacterial periplasm of Escherichia coli cells, we observed periplasmic fluorescence from a chimera of a 150-amino-acid N-terminal truncation of SgsE and EGFP. Based on this finding, unfolding and refolding kinetics of different S-layer-EGFP chimeras, a maltose binding protein-EGFP chimera, and sole EGFP were monitored using green fluorescence as indicator for the folded protein state. Calculated apparent rate constants for unfolding and refolding indicated different folding pathways for EGFP depending on the fusion partner used, and a clearly stabilizing effect was observed for the SgsE_C fusion moiety. Thermal stability, as determined by differential scanning calorimetry, and unfolding equilibria were found to be independent of the fused partner. We conclude that the stabilizing effect SgsE_C exerts on EGFP is due to a reduction of degrees of freedom for folding of EGFP in the fused state.

• The Academic Congress of Korean Shoulder and Elbow Society
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• 2009.03a
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• pp.43-43
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• 2009

Glenohumeral ligaments play an important role in stabilizing the shoulder. However, it is impossible to know how they function in vivo during shoulder motion. To help elucidate this stabilizing role, we conducted in vivo three-dimensional kinematics of the normal shoulder joint using a markerless bone-registration technique. Magnetic resonance images of 14 shoulder joints of 7 healthy volunteers were acquired for 7 isometric abduction positions between $0^{\circ}$ and $180^{\circ}$. We then calculated three-dimensional shortest paths between the origin and insertion of each ligament based on anatomical study in each abduction position. At $0^{\circ}$ of abduction, the posterior band of the coracohumeral ligament displayed the maximum length. At $30^{\circ}$ of abduction, the superior glenohumeral ligament displayed the maximum length. At $60^{\circ}$ of abduction, the anterior band of the coracohumeral ligament and the middle glenohumeral ligament displayed the maximum length. At $120^{\circ}$ of abduction, the anterior band of the inferior glenohumeral ligament displayed the maximum length. We think that the maximum length of these results is an important influence on the function of the soft tissue stabilizer.

• The Journal of the Korea Contents Association
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• v.12 no.3
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• pp.233-243
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• 2012

The purpose of this study was to examine the effects of lumbar stabilization exercise using the PNF techniques on the lumbar deep muscles thickness and functional activity in chronic low back pain patient. Group I(n=10): general physical therapy group; Group II(n=10): general lumbar stabilization exercise group; Group III(n=10): lumbar stabilization exercise using PNF techniques(stabilizing reversal, rhythmic stabilization, combination of isotonic) group. Change of pain was measured with visual analog scale(VAS). To observe muscle thickness changes, we measured transverse abdominis(TrA), external oblique(EO), multifidus with real time ultrasound scanning. The functional activity were measured with Oswestry Disability Questionnaire(ODQ) and Roland & Morris Disability Questionnaire(RMDQ). In VAS test, group III had more significantly decreased than before exercise. In muscle thickness test, group III had more significantly increased than before exercise in right/left TrA, EO, multifidus. In ODQ & RMDQ test, group III had more significantly decreased than before exercise. This study show that the PNF techniques is effective in improving the lumbar stability and functional activity in chronic low back pain patients.

• PNF and Movement
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• v.19 no.1
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• pp.19-29
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• 2021

Purpose: This study aimed to compare the effects of a four-week scapular stabilization exercise program using the PNF technique on scapular symmetry and range of flexion motion (ROM), pain, function, and quality of life (QOL) in post-mastectomy women with breast cancer. Methods: This study included 20 women divided into an experimental group (n = 10) and a control group (n = 10). All patients performed complex decongestive physiotherapy for 40 min daily, five times per week for four weeks. The experimental group performed the extra scapular stabilizing exercise program using the PNF technique for 50 min daily, five times per week for four weeks. Scapular symmetry, shoulder flexion ROM, pain and function, and QOL were subsequently assessed. For ROM measurement, the range of shoulder flexion was measured using a clinometer smart phone application; the pain of the shoulder was measured using the visual analogue scale (VAS); the scapular position was measured using a lateral scapular slide test (LSST); the level of pain and functional activity was measured using the Shoulder Pain and Disability Index (SPADI); and the QOL was measured using Functional Assessment of Cancer Therapy-Breast. Results: There were significant differences in shoulder flexion ROM, VAS, SPADI, and LSST 0˚ and 45˚ when the experimental group was compared with the control group (p < 0.05). After the intervention, there was an improved within-group change in the ROM, SPADI, LSST, and QOL in both the experimental and control groups. Conclusion: These findings suggest that a scapular stabilization exercise program using the PNF technique may be used as a possible treatment option for post-mastectomy women with breast cancer that aims to improve scapular position, shoulder ROM and function, and QOL.

• Bulletin of the Korean Chemical Society
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• v.33 no.3
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• pp.906-910
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• 2012

Hollow gold-silver bimetallic nanoparticles (AuAg-HNPs) have been synthesized and their optical and structural properties were characterized. Initially Ag nanoparticles (Ag-NPs) were prepared using poly(ethylenimine) (PEI) as a reducing and a stabilizing agent simultaneously. AuAg-HNPs could then be synthesized via galvanic replacement reaction in a PEI aqueous solution by reacting sacrificial Ag template with a precursor compound of Au, i.e., $HAuCl_4$. Due to the presence of abundant amine functional groups in PEI, which could act as the dissolving ligand for AgCl, the precipitation problem of $Ag^+$ in the presence of Cl from $HAuCl_4$ salt was avoided. On this basis, the relatively high concentrations of $HAuCl_4$ and PEI-stabilized Ag nanoparticles could be used for the fabrication of AuAg-HNPs. Because of their increased surface areas and reduced densities, the AuAg-HNPs were expected and confirmed to outperform their solid counterparts in applications such as catalysis for the reduction of 4-nitrophenol in the presence of $NaBH_4$.

• Proceedings of the Korean Society of Life Science Conference
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• 2002.12a
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• pp.48-60
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• 2002

Granulocyte-macrophage colony-stimulating factor (GM-CSF) is a cytokine that stimulates the production of granulocytes, macrophages, and white blood cells. The effects of osmotic pressure on secretion of human GM-CSF into the culture medium were investigated in suspension cultures of transgenic tobacco cells. An increase in osmotic pressure caused by the addition of mannitol decreased the cell size index, with the effect being more pronounced when cells were measured wet rather than dry. Increased osmotic pressure enhanced the secretion of hGM-CSF. At 90 g/L mannitol, the maximum concentration tested, hGM-CSF was present in the culture medium at 980 ug/L. As the concentration of mannitol increased, the total amount of protein secreted also increased, but was disproportionately enriched in GM-CSF NaCl, another osmoticum, had very similar effects on cell growth and hGM-CSF production, but did not cause enrichment for hGM-CSF Additionally, protein-stabilizing polymer was added to culture broth to enhance stability of secreted recombinant protein. Finally, above two method were applied together to maximize the productivity.

• Proceedings of the KIEE Conference
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• 1991.07a
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• pp.670-677
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• 1991

All models of dynamical systems invariably have some measure of uncertainties associated with some of their dynamics. The recent approaches to establish robustness of stabilizing feedback control against the possible uncertainties have a serious limitation, that is, their applicability only to the systems that satisfy the matching conditions. Such conditions are rarely met in general applications. If a particular system satisfies the matching conditions, the addition of an actuator will destroy the satisfaction of such conditions. In this paper, we develop robust control algorithm for uncertain multivariable systems in which the matching conditions are not necessarily met. In order to eliminate an influence over partial state variables due to unknown constant disturbances we perform the appropriate block-decomposition for a given system. Functional observers are introduced to estimate the unknown constant disturbances. The sliding mode controller is designed in such a way that the partial state variables in the state-space are directed towards switching surfaces and regulated to the origin asymptotically. Numerical examples are discussed as illustrations.