• 대한통합의학회지
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• 제10권2호
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• pp.203-210
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• 2022

Purpose : The purpose of this study was to investigate the effect of vestibular sensory stimulation exercise on the limit of stability, dynamic weight shift, and upper and lower extremities reaction time in adult women. Methods : This study was conducted with 30 female. All subjects were randomly and equally assigned to an experimental group and a control group of 15 each. Subjects assigned to the experimental group received vestibular sensory stimulation training for 6 weeks. For the intervention, vestibular sensory stimulation exercises were conducted by referring to the Hamid exercise method and the Cawthorne-Cooksey exercise method, and the control group did not receive any intervention. All subjects were tested for limit of stability, dynamic weight shift, and upper and lower extremities reaction time before and after the intervention. Results : The results of this study showed significant differences between groups in reaction time, moving velocity, and directional control in the limit of stability test after intervention. In the dynamic weight shift test after intervention, there was a significant difference between the groups in the slow directional control of left and right. And in the upper and lower extremities reaction time test after intervention, both scores and reaction time showed significant differences between groups. Conclusion : As a result, the three vestibular sensory stimulation exercises applied in this study improved the limit of stability, dynamic weight shift, and upper and lower extremities reaction time.

• Journal of Mechanical Science and Technology
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• 제15권6호
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• pp.743-751
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• 2001

A Prototype reaction wheel, named the Hankuk Aviation University (HAU) reaction wheel, has been developed for KAISTSAT satellite series. Torque and force disturbances are inherent in reaction wheels, and thus the force and torque characteristics should be examined for every newly developed reaction wheel. The torque and force disturbance noises in the prototype HAU reaction wheel are measured with a torque-measuring table developed for the present study. A new measuring procedure based on a simple principle is applied for the measurements. The frequency characteristics of the torque and force noises are analyzed by examining the power spectral density. The effect of the torque noise on the attitude stability is also examined through numerical simulations with a single-axis attitude model. The noise-induced attitude error and jitter and found to be well below the specified error limits for the KAISTSAT satellite series.

• Biotechnology and Bioprocess Engineering:BBE
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• 제11권3호
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• pp.258-261
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• 2006

The addition of zeolite particles enhances the stability of mRNA molecules in a cell-free protein synthesis system. When $20{\mu}g/{\mu}L$ of zeolite (Y5.4) is added to a reaction mixture of cell-free protein synthesis, a substantial increase in protein synthesis is observed. The stabilizing effect of zeolite is most dearly observed in an in vitro translation reaction directed by purified mRNA, as opposed to a coupled transcription and translation reaction. Upon the addition of zeolite in the in vitro translation reaction, the life span of the mRNA molecules is substantially extended, leading to an 80% increase in protein synthesis. The effect of zeolite upon the mRNA stability appears be strongly related to the cation exchange (potassium to sodium) reaction. Our results demonstrate the possibility of modifying this biological process using heterogeneous, non-biological substances in a cell-free protein synthesis system.

• 한국전자통신학회논문지
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• 제6권2호
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• pp.280-287
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• 2011

연구의 목적은 서민주거안정정책이 주택가격에 미치는 영향을 분석하는 것이다. 이에 대한 실증분석을 실시한 결과 다음과 같은 결론을 얻었다. 첫째, 그랜저인과관계를 검증한 결과 전 지역의 주택시장은 서민주거안정정책에 영향을 주고 있는 것으로 나타났다. 둘째, 충격반응은 전 지역에서 부(-)의 반응을 보이며, 서민주거안정정책은 주택시장안정에 어느 정도 기여한 것으로 나타났다. 셋째, 로짓회귀분석결과 서민주거안정정책은 노무현 정부의 강남지역을 제외하고 주택시장안정에 상당한 효과가 있는 것으로 나타났다.

• Bulletin of the Korean Chemical Society
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• 제24권1호
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• pp.86-90
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• 2003

Reverse-Water-Gas-Shift reaction (RWGSR) was carried out over the ZnO, $Al_2O_3,\;and\;ZnO/Al_2O_3$ catalysts at the temperature range from 400 to 700 ℃. The ZnO showed good specific reaction activity but this catalyst was deactivated. All the catalysts except the $ZnO/Al_2O_3$ catalyst (850 ℃) showed low stability for the RWGSR and was deactivated at the reaction temperature of 600 ℃. The $ZnO/Al_2O_3$ catalyst calcined at 850 ℃ was stable during 210 hrs under the reaction conditions of 600 ℃ and 150,000 GHSV, showing CO selectivity of 100% even at the pressure of 5 atm. The high stability of the $ZnO/Al_2O_3$ catalyst (850 ℃) was attributed to the prevention of ZnO reduction by the formation of $ZnAl_2O_4$ spinel structure. The spinel structure of $ZnAl_2O_4$ phase in the $ZnO/Al_2O_3$ catalyst calcined at 850 ℃ was confirmed by XRD and electron diffraction.

• 한국안전학회지
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• 제22권4호
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• pp.43-50
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• 2007

Lack of understanding of the process chemistry and thermodynamics are the major reasons that can is lead to thermal runaway reaction in the chemical reaction process. The evaluation of reaction factors and thermal behavior in neutralization process of pigment plant are described in this paper. The experiments were performed in the C 80 calorimeter, and Thermal Screening Unit($TS^{u}$). The aim of the study was to evaluate the results of thermal stability in terms of safety reliability to be practical applications. It suggested that we be proposed safe operating conditions and securities for accident prevention through this study.

• Journal of Pharmaceutical Investigation
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• 제20권3호
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• pp.145-152
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• 1990

Zirconium pyrithione complex was prepared by reaction of sodium-pyrithione solution and zirconyl chloride solution. The physico-chemical properties of the complex was examined by means of IR, XRD, DSC and NMR. And the stability of Zr-complex was investigated on the basis of accelerated stability analysis under conditions of temp. elevation, UV radiation and pH dependence. The result indicates that the ratio of the ligand to metal in Zr-pyrithione complex was determined 4:1, and its stability constant was $4.643{\times}10^4$. The rate order of decomposition of the complex was apparent first-order reaction of which rate constant and the decomposition rate was not only accelerated by effect of heat and UV radiation but was catalyzed by specific acid-base catalysis considered the pH dependence for the hydrolysis of the complex and the suspension was most stable over the range pH 4-8 indicating that solvent catalysis is the primary made of reaction in this region.

• 한국식품영양과학회지
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• 제26권6호
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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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• 제20권1호
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• pp.35-41
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• 1999

Stability characteristics of hyperbolic reaction-diffusion equations with a reversible Brusselator model are investigated as an extension of the previous work. Intensive stability analysis is performed for three important parameters, Nrd, β and Dx, where Nrd is the reaction-diffusion number which is a measure of hyperbolicity, β is a measure of reversibility of autocatalytic reaction and Dx is a diffusion coefficient of intermediate X. Especially, the dependence on Nrd of stability exhibits some interesting features, such as hyperbolicity in the small Nrd region and parabolicity in the large Nrd region. The hyperbolic reaction-diffusion equations are solved numerically by a spectral method which is modified and adjusted to hyperbolic partial differential equations. The numerical method gives good accuracy and efficiency even in a stiff region in the case of small Nrd, and it can be extended to a two-dimensional system. Four types of solution, spatially homogeneous, spatially oscillatory, spatio-temporally oscillatory and chaotic can be obtained. Entropy productions for reaction are also calculated to get some crucial information related to the bifurcation of the system. At the bifurcation point, entropy production changes discontinuously and it shows that different structures of the system have different modes in the dissipative process required to maintain the structure of the system. But it appears that magnitude of entropy production in each structure give no important information related for states of system itself.

• Biotechnology and Bioprocess Engineering:BBE
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• 제10권4호
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• pp.329-333
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• 2005

This study was designed to investigate the stability of a lipase fused with a cellulose­binding domain (CBD) to cellulase. The fusion protein was derived from a gene cluster of a CBD fragment of a cellulase gene in Trichoderma hazianum and a lipase gene in Bacillus stearother­mophilus L1. Due to the CBD, this lipase can be immobilized to a cellulose material. Factors affecting the lipase stability were divided into the reaction-independent factors (RIF), and the re­action-dependent factors (RDF). RIF includes the reaction conditions such as pH and tempera­ture, whereas substrate limitation and product inhibition are examples of RDF. As pH 10 and $50^{\circ}C$ were found to be optimum reaction conditions for oil hydrolysis by this lipase, the stability of the free and the immobilized lipase was studied under these conditions. Avicel (microcrystal­line cellulose) was used as a support for lipase immobilization. The effects of both RIF and RDF on the enzyme activity were less for the immobilized lipase than for the free lipase. Due to the irreversible binding of CBD to Avicel and the high stability of the immobilized lipase, the enzyme activity after five times of use was over $70\%$ of the initial activity.