• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2453-2455
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• 2005

We represent an efficient intelligent digital redesign method for a Takagi-Sugeno (T-S) fuzzy system Intelligent digital redesign means that an existing analog fuzzy-model-based controller converts to equivalent digital counter part in the sense of state-matching. The proposed method performs previous work, moreover, it allows re matching the states of the overall closed-loop T-S fuzzy system with the predesigned analog fuzzy-model-based controller. And the problem of stability represent convex optimization problem and cast into linear matrix inequality (LMI) framework. This method applies to the helicopter systems which are the nonlinear plant and determine the feasibility and effectiveness of the proposed method.

• Proceedings of the KIEE Conference
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• 2005.07b
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• pp.1811-1813
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• 2005

We represent an efficient intelligent digital redesign method for a Takagi-Sugeno(T-S) fuzzy system. Intelligent digital redesign means that an existing analog fuzzy-model-based controller converts to equivalent digital counter part in the sense of state-matching. The proposed method performs previous work, moreover, it allows to matching the states of the overall closed-loop T-S fuzzy system with the predesigned analog fuzzy-model-based controller. And the problem of stability represent convex optimization problem and cast into linear matrix inequality(LMI) framework. This method applies to the helicopter systems which are the nonlinear plant and determine the feasibility and effectiveness of the proposed method.

• Honam Mathematical Journal
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• v.45 no.3
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• pp.542-554
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• 2023

Given a real number α, the Lagrange number of α is the supremum of all real numbers L > 0 for which the inequality |α - p/q| < (Lq²)^-1 holds for infinitely many rational numbers p/q. All Lagrange numbers less than 3 can be arranged as a set {l_p/q : p/q ∈ ℚ ∩ [0, 1]} using the Farey index. The present paper considers a function C(α) devised from Sturmian words. We demonstrate that the function C(α) contains all information on Lagrange numbers less than 3. More precisely, we prove that for any real number α ∈ (0, 1], the value C(α) - C(0) is equal to the sum of all numbers 3 - l_p/q where the Farey index p/q is less than α.

• Communications of the Korean Mathematical Society
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• v.39 no.3
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• pp.657-671
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• 2024

In this paper, we use higher order derivatives with regard to symmetric points to introduce a class of multivalent starlike functions. The major deviation is that we define some differential characterizations that are subordinate to a function whose real part is not greater than zero. The primary outcomes of this study are initial coefficients and the Fekete-Szegő inequality for functions falling under the given class. Also, we have obtained an interesting subordination results involving symmetric functions. The results obtained here extend or unify the various other well-known and new results.

• Journal of the Korean Institute of Intelligent Systems
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• v.11 no.7
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• pp.621-627
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• 2001

In this paper, a novel and efficient global intelligent digital redesign technique for a Takagi-Sugeno (TS) fuzzy system is addressed. The proposed method should be notably discriminated from the previous works in that in allows us to globally match the states of the closed-loop TS fuzzy system with the pre-designed continuous-time fuzzy-model-based controller and those with the digitally redesigned fuzzy-model-based controller, and further to guarantee the stabilizability by the redesigned controller in the sense of Lyapunov. Sufficient conditions for the global state-matching and the stability of the digitally controller system are formulated in terns of linear matrix inequalities (LMIs). The Duffing-like chaotic oscillator is simulated and demonstrated, to validate the effectiveness of the proposed digital redesign technique, which implies the safe applicability to the digital control system.

• Journal of the Korea Society of Computer and Information
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• v.22 no.12
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• pp.163-170
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• 2017

The purpose of this study is to introduce policy and theoretical implications by analyzing affecting factors for the elder's happiness. For this study, we analyzed data using HLM. Data include a world value survey(hereafter, WVS) as personal level analysis data and also OECD's Social Expenditure Database(hereafter, SOCX) and database from the World Bank as national level analysis data. The subjects of personal level analysis were the elder who are over 65-years od age, and they were total 3,297 people, and while the subjects of national level analysis were total 9 OECD countries. For the data analysis, hierarchial linear model(HLM) analysis was done by using HML 7.0 program. As a result of analysis, First, for the elderly's happiness, they should improve self-disposition, members of social groups, and social class. Second, the old-age pension and the survivor's pension had no meaningful effect on the happiness. but it was found that self - disposition, social class, gender, and health status showed meaningful interaction effect according to old - age pension, survivor pension, per capita GDP, income inequality. This suggests that efforts to improve the happiness of the elderly should be made at the individual level and the national level at the same time.

• Journal of the Korean Society for Library and Information Science
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• v.43 no.2
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• pp.329-350
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• 2009

The purpose of this study is to develop the indicators of user satisfaction for Korean public library evaluation. This is an attempt to overcome the inequality of indicators, which mainly consist of inputs and outputs. User satisfaction indicators are constructed through literature reviews and the prepared indicators are tested through a user survey of public libraries. Notably, the test is focused on the applicability of indicators for public libraries with a variety characteristics such as scale and operation organization. Based on the analysis of the results, this study suggests a total of 10 indicators.

• Journal of Family Resource Management and Policy Review
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• v.12 no.3
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• pp.45-58
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• 2008

The purpose of this study is to determine how the culture of modern mass consumption is understood in determining a decent lifestyle. This study examined a variety of literature on this problem. The important results are as follows. The culture of consumption has evolved through the increase of productivity in modern industry. People's desires have instigated a developing consumption culture: the concepts of advertising, fashion, over-consumption, and conspicuous consumption. The dissemination of this new consumption culture in an information-rich society, facilitated by the popularization of the Internet, has started to influence every nook and comer of our lives. This change of lifestyle has resulted not only in positive effects, but also in negative ones, such as distortion of information, and inequality. Thus the culture of modern mass consumption has created a new concept of class order and has reinforced the unbalance between opinion-leaders and opinion-followers. It has also increased the ratio of needs to wants. Consumption makes escape and sensual pleasure possible. The conclusion of this study is that the culture of modern mass consumption has not upheld its original purpose, that is, the qualitative enrichment of life through consumption. It has only caused the disintegration of individuality.

• Journal of Institute of Control, Robotics and Systems
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• v.22 no.6
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• pp.453-462
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• 2016

This paper proposes a torque control method for surface mounted permanent magnetic synchronous motor (PMSM) driven by a 2-level voltage source driven inverter, which has fast torque response and small torque ripple. The proposed torque control method follows the finite control set model predictive control (FCS-MPC) strategy. A reference state is derived at each time step for the given time varying torque reference and the cost index is defined so that the tracking error for this reference state should be penalized. The choice of an optimal output voltage vector is made first from the 6 possible active voltage vectors of the 2-level voltage source inverter. Then a modulation factor for the chosen optimal voltage vector is obtained so that the torque ripple can be reduced further. It is shown that the proposed FCS-MPC control method yields fast torque tracking response and small torque ripple through simulation and experiments.

• Structural Engineering and Mechanics
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• v.56 no.3
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• pp.385-407
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• 2015

This paper deals with the problem of the global stabilization for a class of tension leg platform (TLP) nonlinear control systems. It is well known that, in general, the global asymptotic stability of the TLP subsystems does not imply the global asymptotic stability of the composite closed-loop system. Finding system parameters for stabilizing the control system is also an issue need to be concerned. In this paper, we give additional sufficient conditions for the global stabilization of a TLP nonlinear system. In particular, we consider a class of NN based Takagi-Sugeno (TS) fuzzy TLP systems. Using the so-called parallel distributed compensation (PDC) controller, we prove that this class of systems can be globally asymptotically stable. The proper design of system parameters are found by a swarm intelligence algorithm called Evolved Bat Algorithm (EBA). An illustrative example is given to show the applicability of the main result.