• Journal of Electrical Engineering and Technology
• /
• v.13 no.3
• /
• pp.1110-1122
• /
• 2018

This paper proposes an alternative method to evaluate the effect of wind power to the power system stability with small disturbance. Alternatively, available techniques for stability analysis of a power system based on deterministic methods are less accurate for high penetration of wind power. Numerical simulations of random behaviors are computationally expensive. A stochastic stability index (SSI) is proposed for the power system stability evaluation based on the theory of stochastic stability and energy function, specifically the stochastic derivative of the relative well-defined energy function and the critical energy. The SSI is implemented on the modified nine-bus system including wind turbines under different conditions. A doubly-fed induction generator (DFIG) wind turbine is characterized and modeled using measured wind data from several sites in Thailand. Each of the obtained wind power data is analyzed. The wind power effect is modeled considering the aggregated effect of wind turbines. With the proposed method, the system behavior is properly predicted and the stability is quantitatively evaluated with less computational effort compared with conventional numerical simulation methods.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
• /
• v.24 no.2
• /
• pp.59-67
• /
• 2018

Background: The purpose of this study was to investigate the effects of gluteus medius strength exercise on the ankle stability of high school student with chronic ankle sprains. Methods: A total of 30 participants were divided two groups. Experimental group was 15 participants applied gluteus medius strength exercise. Control group was 15 participants performing ankle strength exercise. This study was performed for 50 minutes per day, three a week for 6 weeks. All measurements were taken to a pre and post test. Strength was measured using Power Track ll. Balance was measured using Biodex balance system for Limits of Stability and Postural Stability. Ankle Stability was measured using Cumberland Ankle Instability Tool (CAIT). Results: In the case of gluteus medius strength, there were statistically significant differences between the experimental group and the control group. For ankle stability were statistically significant differences within the experimental group according to measurements taken by Limits of Stability, Postural Stability, and CAIT. A between group comparison showed a statistically significant difference for CAIT only. Conclusion: According to our measurements it appears that gluteus medius strength training was effective in benefiting muscular strength, balance and ankle stability among the physical education.

• Advances in concrete construction
• /
• v.7 no.2
• /
• pp.97-105
• /
• 2019

In this paper, the workability and static stability were evaluated using a proposed test method. Workability and static stability represent a key property of self-compacting concrete (SCC) in fresh state. A number of standardized test methods were developed to assess these properties. However, no accelerated test method reliably predicts both workability and static stability of SCC. In the present work, a modified K-slump test method was developed to evaluate workability and static stability of SCC. In order to take implicit mixture variations of SCC constituents that can affect fresh SCC properties, a central composite design was adopted to highlight the effect of gravel to sand ratio (G/S), gravel 3/8 to gravel 8/15 ratio (G1/G2), water to cement ratio (W/C), marble powder to cement ratio (MP/C) and superplasticizer content (SP) on workability measured with slump and flow time (T50) tests and static stability measured with sieve stability test (Pi), segregation test index (SSI), Penetration test (Pd) and the proposed K-slump test (Km). The obtained results show that G/S ratio close to 1 and G1/G2 ratio close to 60% can be considered as optimal values to achieve a good workability while ensuring a sufficient static stability of SCC. Acceptable relationships were obtained between Slump flow, Pi, Pd and Km. Results show that the proposed K-slump test allow to assess both workability and static stability of fresh SCC mixtures.

• The Journal of Asian Finance, Economics and Business
• /
• v.9 no.8
• /
• pp.183-196
• /
• 2022

Bank stability serves as a prerequisite for the smooth functioning of economic and financial activities in the country. Banks face numerous risks, and liquidity plays an essential role in determining a bank's long-term growth and financial stability. By using the sample of 70 banks of the Gulf Cooperation Council, this study examines the association between funding the liquidity and the creation of liquidity and their impact on bank stability. Firstly, the reciprocal relationship reveals between funding the liquidity and the creation of liquidity by employing the 2SLS regression model. Further, by employing the dynamic GMM model, the research finds that funding liquidity is significant and positively influences bank stability. However, bank stability is significantly negatively influenced by the creation of liquidity, but the combined effect of funding the liquidity and creation of liquidity positively explains the bank stability. Additionally, this study reveals that managerial optimism biases contribute to determining the bank's liquidity and long-term stability. The finding of this study supports the executives, policymakers, and management of banks in understating liquidity risks, efficiency, and bank stability. The findings support regulatory guidelines mainly by the Basel III framework, which places more importance on the joint management of funding the liquidity and creation of liquidity in the economy.

• Bulletin of the Korean Mathematical Society
• /
• v.34 no.3
• /
• pp.437-446
• /
• 1997

In this paper, the Hyers-Ulam stability and the general Hyers-Ulam stability (more precisely, modified Hyers-Ulam-Rassias stability) of the gamma functional equation (3) in the following setings $$ \left$\mid$ f(x + 1) - xf(x) \right$\mid$ \leq \delta and \left$\mid$ \frac{xf(x)}{f(x + 1)} - 1 \right$\mid$ \leq \frac{x^{1+\varepsilon}{\delta} $$ shall be proved.

• Proceedings of the Korean Geotechical Society Conference
• /
• 2003.03a
• /
• pp.485-492
• /
• 2003

In this study, We peformed on the effective evaluation of slope berm construction using slope stability analysis programs. The effective evaluation of slope berm construction was performed by stability of slope and economy of construction. This time, used slope stability analysis programs are Talren97 that use Limit equilibrium method (LEM) and FLAC-SLOPE that use finite difference method (FDM), and carried out using Rocfall program to evaluate slope stability by rockfall occurrence.

• Journal of the Korean Mathematical Society
• /
• v.35 no.2
• /
• pp.449-463
• /
• 1998

In this paper we introduce the notions of orbital Lipschitz stability (in variation) and orbital exponential asymptotic stability (in variation) of $C^{r}$ dynamical systems (or $C^{r}$ diffeomor-phisms) on Riemannian manifolds, and study the embedding problem of those concepts in $C^{r}$ dynamical systems.stems.

• Korean Journal of Mathematics
• /
• v.24 no.1
• /
• pp.1-13
• /
• 2016

This paper shows that the solutions to the perturbed functional dierential system $$y^{\prime}=f(t,y)+{\int_{t_0}^{t}}g(s,y(s),Ty(s))ds$$ have uniformly Lipschitz stability and asymptotic property. To sRhow these properties, we impose conditions on the perturbed part ${\int_{t_0}^{t}}g(s,y(s),Ty(s))ds$ and the fundamental matrix of the unperturbed system $y^{\prime}=f(t,y)$.

• Microbiology and Biotechnology Letters
• /
• v.19 no.1
• /
• pp.100-108
• /
• 1991

Molecular characteristics and improving methods for thermal stability of enzyme have been considered. Intrinsic and extrinsic stabilizing mechanisms are two governing principles for enhanced thermal stability of enzyme in molecular basis. Factors contributing to the former and the latter mechanisms may be involved in the enhanced thermal stability of enzyme complementarily. Also, the methods for improving thermal stability of enzyme which comprise reaction in organic solvent system, chemical modification, immobilization, sequential unfolding and refolding, gene manipulation techniques and enzyme-antibody complexing are reviewed.

• 제어로봇시스템학회:학술대회논문집
• /
• 1995.10a
• /
• pp.5-9
• /
• 1995

In many cases of robust stability problems, the characteristic polynomial has real coefficients which or nonlinear functions of uncertain parameters. For this set of polynomials, a new stability easily checking algorithm for reducing the conservatism of the stability bound are given. It is the new stability theorem to determine the stability region just in parameter space. Illustrative example show that the presented method has larger stability bound in uncertain parameter space than others.