• Journal of the Chungcheong Mathematical Society
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• v.21 no.3
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• pp.395-401
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• 2008

In this paper we investigate h-stability for linear dynamic equations on time scales under $u_{\infty}$-similarity.

• Journal of Korean Society of Forest Science
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• v.109 no.1
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• pp.99-108
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• 2020

Although the relationship between income and income inequality has previously been discussed, the present study applies a dynamic approach to analyze the specific relationship between forest household income and income inequality. For this analysis, a unit root test and a cointegration test were conducted to characterize the nature of income time-series data. After converting unstable time-series data into stable time-series data, a VAR model was estimated. Based on this model, an impulse-response was generated and variance-decomposition analysis was performed. These analyses showed that the effect of forest household income was relatively larger than that of the Gini coefficient, and that the impact of forest household income not only caused income to increase but also caused the Gini coefficient to decrease. In addition, the impact of the Gini coefficient had an impact on reducing forest household income and further increasing income inequality. We conclude that, with the aim of alleviating the inequality of forest household income, an income growth policy would be more effective than an income distribution policy.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.11
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• pp.7788-7793
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• 2015

Both export and import sides of grain trade market are analyzed and compared in terms of the static levels and dynamic trends to make new empirical inference on the imperfect competition degree. Export concentration level is high compared to import concentration level. And such states have been sustained since 2001 until 2014. Unlike public concerns, the concentration level of export side seems to be easing by small degree. However, the grain trade market remains imperfect competitive market. Furthermore, overall imperfective competition condition over 2002-2014 has been worsened compared to 2001 level. It is because the reduction level of imports concentration is higher than that of the export concentration. Gini and Atkinson Inequality Index based on Lorenz Curve are newly utilized to analyze market concentration level, instead of the commonly used concentration ratio.

• Journal of Korean Medicine Rehabilitation
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• v.21 no.3
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• pp.13-20
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• 2011

Objectives : We studied the clinical utility of meridian electromyography for the assessment of erector spinae muscle in functional leg length inequality. Methods : We compared electrical activity between A group with a functional leg length inequality(n=17) and B group(n=23) in dynamic flexion-reextension state during five minutes. We anayzed amplitudes and areas of electrical activity and asymmetry index(AI). Results : 1. The short leg sides were significantly higher electrical activity than the long leg sides in the experimental group and control group(p<0.05). 2. The AI of A group significantly higher than B group(p<0.05). Conclusions : According to above results, there are correlations between erector spinae muscle and functional leg length inequality.

• Journal of the Korean Institute of Intelligent Systems
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• v.17 no.6
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• pp.780-785
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• 2007

This paper proposes the decentralized dynamic output feedback controller for discrete-time nonlinear interconnected systems using Takagi-Sugeno (T-S) fuzzy model. Through T-S fuzzy model of each subsystem, the decentralized dynamic output feedback controller is designed. By the closed-loop subsystems with controller, it represents the linear matrix inequality (LMI) for stability of whole interconnected system. The value of control gain are obtained by LMI. An example is given to show the experimentally verification discussed throughout the paper.

• Journal of Advanced Marine Engineering and Technology
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• v.26 no.3
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• pp.313-319
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• 2002

Since the oil crisis in 1970, a great deal of effort has been made to develop automatic electric load sharing systems as a part of the efforts to save energy. A large scale electric generating system composes more than two generators whose characteristics may be different. When such a system is operated individually or in parallel, the lagrange multiplier's method has difficulty in achieving optimal load distribution because generators usually have the limitations of the operating range with inequality constraints. Therefore, a suitable operating mode of generators has to be decided according to the selection of the generators to meet electric power requirements at the minimum cost. In this study, a method which solves the optimal electric load distribution problem using the dynamic programming technique is proposed. This study also shows that the dynamic programming method has an advantage in dealing with the optimal load distribution problem under the limitations of the operating range with inequality constraints including generator operation mode. In this study, generator operating cost curve of second order equation by shop trial test results of diesel generators are used. The results indicate that the proposed method can be applied to the ship's electric generating system.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.515-515
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• 2000

The performance of dynamic path following of a wheeled mobile robot with nonholonomic constraints has some drawbacks such as the influence of the initial state. The drawbacks can be overcome by the temporary path generator and modified output. But with the previous input-output linearization method using them, it is difficult to tune the gains, and if there are some modeling errors, the low gain can make the system unstable. And if a high gain is used to overcome the model uncertainties, the control inputs are apt to be large so the system can be unstable. In this paper. an H$_{\infty}$ controller is designed to guarantee robustness to model parameter uncertainties and to consider the magnitude of control inputs. And the solution to Hamilton Jacobi (HJ) inequality, which is essential to H$_{\infty}$ control design, is obtained by nonlinear matrix inequality (NLMI).

• Korean Journal of Organic Agriculture
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• v.23 no.4
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• pp.683-702
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• 2015

The static status and dynamic trend of the market structure in the international wheat trade market are empirically analyzed. The export inequality level empirically proved to be high compared to import inequality level. And such states have been maintained since 2001 until 2014. Although the concentration level of export side seems to be easing, the international wheat market remains imperfect competitive market. Moreover, overall imperfect competitive status over 2002-2014 has been worsened compared to 2001 level. The main reasons are that the overall trends of the imports concentration is reduced more than those of the export concentration level.

• Journal of applied mathematics & informatics
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• v.41 no.3
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• pp.487-510
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• 2023

We propose a mathematical model which describes the frictional contact between a piezoelectric body and an electrically conductive foundation. The behavior of the material is described with a linearly electro-viscoelastic constitutive law with long term memory. The mechanical process is dynamic and the electrical conductivity coefficient depends on the total slip rate, the friction is modeled with Tresca's law which the friction bound depends on the total slip rate with taking into account the electrical conductivity of the foundation both. The main results of this paper concern the existence and uniqueness of the weak solution of the model; the proof is based on results for second order evolution variational inequalities with a time-dependent hemivariational inequality in Banach spaces.

• Proceedings of the KSRS Conference
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• 2005.10a
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• pp.294-297
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• 2005

Time series are comprehensively appeared and developed in many applications, ranging from science and technology to business and entertainrilent. Similarity search under time warping has attracted much interest between the time series in the large sequence databases. DTW (Dynamic Time Warping) is a robust distance measure and is superior to Euclidean distance for time series, allowing similarity matching although one of the sequences can elastic shift along the time axis. Nevertheless, it is more unfortunate that DTW has a quadratic time. Simultaneously the false dismissals are come forth since DTW distance does not satisfy the triangular inequality. In this paper, we propose an efficient range query algorithmbased on a new similarity search method under time warping. When our range query applies for this method, it can remove the significant non-qualify time series as early as possible before computing the accuracy DTW distance. Hence, it speeds up the calculation time and reduces the number of scanning the time series. Guaranteeing no false dismissals, the lower bounding function is advised that consistently underestimate the DTW distance and satisfy the triangular inequality. Through the experimental result, our range query algorithm outperforms the existing others.