• Transactions on Control, Automation and Systems Engineering
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• v.2 no.4
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• pp.274-284
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• 2000

In this paper, the design methodology of digital fuzzy controller(DFC) for the systems with time-delay is presented and the qualitative effects of the quantizers in digital implementation of a fuzzy controllers are investigated. We propose the fuzzy feed-back controller whose output is delayed with unit sampling period and period and predicted. the analysis and the design problem considering time-delay become very easy because the proposed controller is syncronized with the sampling time. The stabilization problem of the digital fuzzy system with time-delay is solved by linear matrix inequality(LMI) theory. Furthermore, we analyze the stability of the quantized fuzzy system. Our results prove that when quantization os taken into account, one only has convergence to some small neighborhood about origin. We develop a fuzzy control system for backing up a computer-simulated truck-trailer with the consideration of time-delay and quantization effect. By using the proposed method, we analyze the quantization effect to the system and design a DFC which guarantees the stability of the control system in the presence of time-delay.

• Journal of Digital Convergence
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• v.15 no.12
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• pp.625-633
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• 2017

The purpose of this study is to investigate the effect of private insurance revenues and household spending on household income inequality. To this end, we conducted a concentration index and concentration curve analysis for the income level of medical panel survey data in 2015. The main results are as follows. First, the household income concentration ratio is 0.3580, which means that income is concentrated in the high income group, and the degree of inequality is considerably large. Second, although the portion of the private insurance benefits was small on the high-income household, it helped to strengthen the benefits concentration on this group. Third, the low income group has a large self-pay medical expense. Finally, the index of the income excluding the burden of the total medical expenses in the household income was 0.3676, so that even accounting for medical expenses, the income was concentrated in the high income class. Therefore, private insurance benefits and medical expenses were all contributing factors to the inequality of household income, and this study provides the essential materials for research and policy planning which could lead to the convergence of different fields.

• Informatization Policy
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• v.28 no.4
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• pp.3-18
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• 2021

The 'digital divide' is regarded as a latent dysfunction that impedes the intrinsic role of information to contribute to social equality. Therefore, it has drawn great attention inside and outside of academia. The growing interest in the digital divide has been driven by the realization that it can create a serious crisis that threatens a social system compounded by existing economic, social, and cultural inequality, rather than being limited to an uneven distribution of information. In this paper (1) studies on the digital divide published since 1970 are reviewed, (2) studies noteworthy of discussion are selected to assess their academic significance, and (3) the tasks and prospects of digital divide research are explored. Although meaningful achievements have been amassed through continuous interest and efforts of the academic community, two limitations are raised; the gap between pure research and policy research that hinders the working of synthetic imagination, and the intellectual lag falling behind a rapidly changing society. In addition, it is suggested that the operation, curation, and augmentation gaps would emerge as new agenda for digital divide research in the intelligent information age.

• Journal of Digital Convergence
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• v.16 no.12
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• pp.77-86
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• 2018

This study was carried out by using the concentration index calculation method from 1996 to 2016 by using the household trend survey data to confirm the difference of income transfer income and inequality in public transfer income. The main results are as follows. First, the public transfer income concentration index in 1996 was concentrated on the high income group with +0.2774, but since 2009, the concentration index has been negative (-), which has concentrated on the low income group. However, the effect of redistribution of income was small. Second, the average public transfer income of low - income households increased significantly while the number of high income earners decreased. It is gradually improving that public transfer income did not play a role in the improvement of income inequality. Third, public transfer income has been continuously increasing in all income classes, and the rate of increase is low in the low income class and slow in the high income class, so the public transfer income of the low income class is higher than that of the high income class. In sum, the inequality of public transfer income by income class in Korea is gradually improving, but it is not considered to be a level that can improve the inequality between income groups.

• Journal of The Korean Association of Information Education
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• v.11 no.4
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• pp.433-445
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• 2007

Digital divide comes to appear as a new factor of causing social inequality with the entry of information society. Especially, the digital divide in student class makes a worry about education inequality as the education using ICT, e-learning, and u-learning are enlarged. So, the concern about the status of digital divide in school is increasing. In this study, we conducted a questionnaire survey of students and teachers in elementary and secondary schools located in Gyeongnam, and measured informatization level with the weighted average of three subindices : accessing index, capability index, and utilization index. According to the survey, the index on information processing capability showed the largest gap in both the student group and the teacher group. We also had the result of positive correlation between the capability index and the utilization index. These results show that the gap of information processing capability is an important factor for understanding the digital divide.

• Journal of Electrical Engineering and Technology
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• v.7 no.3
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• pp.420-428
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• 2012

In this paper, a novel intelligent digital redesign (IDR) technique is proposed for the nonlinear interconnected systems which can be represented by a Takagi-Sugeno (T-S) fuzzy model. The IDR technique is to convert a pre-designed analog controller into an equivalent digital one. To develop this method, the discretized models of the analog and digital closed-loop system with the decentralized controller are presented, respectively. Using these discretized models, the digital decentralized control gain is obtained to minimize the norm between the state variables of the analog and digital closed-loop systems and stabilize the digital closed-loop system. Its sufficient conditions are derived in terms of linear matrix inequalities (LMIs). Finally, a numerical example is provided to verify the effectiveness of the proposed technique.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.29 no.3
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• pp.271-295
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• 2018

Information inequality has been differently conceptualized and defined in national laws. While the information inequality increases, library policy and informational service has lagged behind in meeting the needs of the society and the state. This paper aims to provide a preliminary research on information inequality, in terms of conceptualization, the legal base, terminology, index development based on the level of digital information. The paper also highlights cases on library services for solution of the difference. It compares library services designed for the disabled, ethnic minorities and the aged. The paper reviews the existing literature and project data. As a result, there are a number of processes and tasks that needs to be developed, including policy development, supporting organization, human capital, cooperating network, supporting facilities and service, and data.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1289-1294
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• 2003

This paper proposes a novel and efficient intelligent digital redesign technique for a Takagi-Sugeno (TS) fuzzy system. The term of intelligent digital redesign involves converting an existing analog fuzzy-model-based controller into an equivalent digital counterpart in the sense of state matching. In this paper, we suggest the discretization method based on the dual-rate sampling approximation is first proposed, and then attempt to globally match the states of the overall closed-loop TS fuzzy system with the pre-designed analog fuzzy-model-based controller and those with the digitally redesigned fuzzy-model-based controller. To show the feasibility and the effectiveness of the proposed method, a computer simulation is provided.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.1 no.1
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• pp.113-118
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• 2001

In this paper, we develop an optimal intelligent digital redesign method for a class of fuzzy-model-based controllers, effective for stabilization of continuous-time complex nonlinear systems. Takagi-Sugeno (TS) fuzzy model is used to extend the results of the classical digital redesign technique to complex nonlinear systems. Unlike the conventional intelligent digital redesign technique reported in the literature, the proposed method utilized the recently developed LMI optimization technique to obtain a digitally redesigned fuzzy-model-based controller. Precisely speaking, the intelligent digital redesign problem is converted to an equivalent optimization problem, and the LMI optimization method is used to find the digitally redesigned fuzzy-model-based controller. A numerical example is provided to evaluate the feasibility of the proposed approach.

• Journal of Digital Convergence
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• v.13 no.5
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• pp.177-185
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• 2015

The gender difference in social roles affects digital devices' utilization differences in man and woman even in the 21st Century. Prior studies analyze the digital divide (genders, ages, etc.) from the assessment perspectives of digital equipment, such as PCs. In the area of high speed internet, most functions of PCs have been replaced with smartphones, and around 80% of the mobile phone users adopt smartphones. Subsequently the inequality of physical access to the digital devices is no longer a criterion for digital divide. The focus on digital divide should be shifted from the physical access to other factors, such as socio-technical or socio-cultural ones. This paper examines utilization of women's digital equipment, in particular, preparing for tourism activities, which is popular but sensitive to the technology. A survey was conducted with participants of [Suncheon Garden Expo] 2013. The results of this study capture the inactive use of digital devices particularly women over 50s. This phenomenon (high utilization of the digital devices for social or informative purposes, but low utilization of the digital payment) implies other aspects of Korean women (economic independence, low self-assertion, technical difficulties, etc.), which is considered from the socio-technological convergence perspective. This study also has a practical implication on the side of the digital device developers as well as marketing, where the qualitative communication is likely to be incorporated for the women over 50s.