• Communications of the Korean Mathematical Society
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• v.30 no.3
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• pp.253-267
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• 2015

Given a complex submanifoldM of the projective space $\mathbb{P}$(T), the hyperplane system R on M characterizes the projective embedding of M into $\mathbb{P}$(T) in the following sense: for any two nondegenerate complex submanifolds $M{\subset}\mathbb{P}$(T) and $M^{\prime}{\subset}\mathbb{P}$(T'), there is a projective linear transformation that sends an open subset of M onto an open subset of M' if and only if (M,R) is locally equivalent to (M', R'). Se-ashi developed a theory for the differential invariants of these types of systems of linear differential equations. In particular, the theory applies to systems of linear differential equations that have symbols equivalent to the hyperplane systems on nondegenerate equivariant embeddings of compact Hermitian symmetric spaces. In this paper, we extend this result to hyperplane systems on nondegenerate equivariant embeddings of homogeneous spaces of the first kind.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.747-750
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• 1996

This paper considers the problem of robust H$_{\infty}$ control with regional stability constraints via output feedback to assure robust performance for uncertain linear systems. A robust H$_{\infty}$ control problem and the generalized Lyapunov theory are introduced for dealing with the problem, The output feedback H$_{\infty}$ controller makes the controlled outputs settle within a given bound and the control input not to be saturated. The regional stability constraints problem for uncertain systems can be reduced to the problem for the nominal systems by finding sufficient bounds of variations of the closed-loop poles due to modeling uncertainties. A controller design procedure is established using the Lagrange multiplier method. The controller design technique was illustrated on the track-following system of a optical disk drive.ve.

• Journal of Institute of Control, Robotics and Systems
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• v.5 no.5
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• pp.511-520
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• 1999

An anti-reset windup (ARW) based compensation method for state constrained control systems is studied. First, a linear controller is constructed to give a desirable nominal performance ignoring state-constraints of a plant. Then, an additional compensator is introduced to provide smooth performance degradation under state-constraints of the plant. This paper focuses on the effective design method of the additional compensator. By minimizing a reasonable performance index, the proposed compensator is expressed in terms of theplant and ocntroller parameters. The resulting dynamics of the compensated controller exhibits the dominant part of the linear closed-loop system which can be seen from the singular perturbation model reducton theory. THe proposed method guarantees total stability of overall resulting systems if linear controllers were constructed to meet certain condition.

• Journal of Institute of Control, Robotics and Systems
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• v.20 no.3
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• pp.333-344
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• 2014

This is the survey paper on the role of kinematics in robot development. The robot is considered as a form of mechanical systems which includes closed-chain loop system, open-chain loop system and closed and open switching system. To analyze these systems, kinematic notations has been developed in kinematics of mechanical theory since 1955 and has been applied in robotics. Several kinematic notations including Denavit-Hartenberg notations have been reviewed. The status of development of the spherical motor which has a great impact on the future robot advancement has reviewed, and research activity on a spherical motor and its application to 3-D spatial mechanisms at UNIST is introduced. For the open and closed switching mechanical systems, the bipedal robots' walking theories using Zero Moment Point are reviewed. And current status regarding bipedal robots based on newly developed passive dynamic walking theory is reviewed with the research activity at UNIST on this subject.

• International Journal of Control, Automation, and Systems
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• v.4 no.5
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• pp.653-659
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• 2006

The design of $H_2$-optimal control with regional pole assignment via state feedback in linear time-invariant systems is investigated. The aim is to find a state feedback controller such that the closed-loop system has the desired eigenvalues lying in some desired stable regions and attenuates the disturbance between the output vector and the disturbance vector. Based on a proposed result of parametric eigenstructure assignment via state feedback in linear systems, the considered $H_2$-optimal control problem is changed into a minimization problem with certain constraints, and a simple and effective algorithm is proposed for this considered problem. A numerical example and its simulation results show the simplicity and effectiveness of this proposed algorithm.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.5 no.3
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• pp.216-221
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• 2005

The rapid growth and spread of the World Wide Web has made it possible to easily access a variety of useful information. It is, however, very difficult to retrieve, manage, and use the desired information in web. Various kinds of systems such as Search engines, MetaSearch engines, Spiders, Softbots, Intelligent Agents or Web Agents have been developed by a large number of researchers and companies. Those systems as intelligent agent are employed to avoid the overload of information. To efficiently improve the Software Agents, it is necessary to represent and classify the retrieved data. And to improve performance of the Intelligent Agents to create the classification, it is offered how to evaluate the propriety with other information retrieved from the Web and to recommend to the user the most suitable information.

• Journal of Information Technology Applications and Management
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• v.18 no.1
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• pp.75-100
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• 2011

For decades, thousands of corporation introduced knowledge management systems to respond knowledge-based society. However, it seems that the systems merely focusing on knowledge accumulation and its sharing have been bounded by many restrictions in terms of new knowledge creation based on the life cycle of knowledge management systems. Moreover, recently, a variety of knowledge management activities regarding organization, systems, and process is emphasized as a strategic asset for a corporation to create core knowledge. Therefore, this study adopted the Csikszentmihalyi's flow theory to investigate the factors affecting knowledge creation and the success factors of knowledge management systems in virtual space. Prior studies argued that flow experience should be a prerequisite for creative knowledge creation. In that vein, this research revealed the causal relationships for flow experience between the determinants of clear goal, immediate feedback, congruence of challenge and skill. Additionally, it empirically examined how flow experience affected the exploratory behavior of knowledge creation.

• Asia pacific journal of information systems
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• v.33 no.4
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• pp.899-933
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• 2023

The second-generation mobile instant messaging (SMIM) proliferates with various relationship management functions: group chats, audio/video chats, file sharing, real-time location sharing, and nonverbal graphics, such as emojis and stickers. This study integrates the important but often overlooked affordances theory into innovation diffusion and proposes an SMIM continuance intention model. SMIM is a social affordance platform for users to develop new friendships and maintain their relationships. Integrated diffusion of innovation and affordance theoretical frameworks, this study investigates the influence of four factors on the success of using SMIM apps to improve friendship development and relationship management. Data were collected from 231 participants using a survey questionnaire in a public university in Taiwan. The findings confirm the effects of friendship development and relationship maintenance on the intention of users to continue using SMIM apps. Implications for research and practice are discussed.

• Management & Information Systems Review
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• v.35 no.2
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• pp.119-136
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• 2016

The purpose of this study are as follows : First, This study conceptually provide an insight of reasons that organizations seek to create, acquire, store and distribute knowledge at the level of an organization and of process how they can transform or evolve to knowledge based organizations. Second, this study confirms examine what theories can be used to knowledge management, how such theories can be useful to analyse knowledge management and provide a theoretical foundation for knowledge management research. Applied to the theories of knowledge based and resource based view and institutional theory, the essence of knowledge management confirms that the organization finds job-related knowledge and know-how retained by individual of organizational members systematically and shares common knowledge within the organization and explains knowledge creation, multi-dimensional knowledge transition and share in all dimension of individual, group, and organization. As a result of comparative analysis of theory of organizational knowledge creation theory, In knowledge management, building of knowledge-creative culture, transitional process of explicit knowledge and tacit knowledge, knowledge creation and knowledge operation are important. In the basis on these study results, we discussed how the organizational knowledge creation theory can be used to manage knowledge in the organization, and also proposed hypotheses based on some arguments against the universal acceptance of the theory.

• Smart Structures and Systems
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• v.5 no.5
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• pp.531-546
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• 2009

In the present analysis, the spline finite strip with higher-order shear deformation is formulated for the static analysis of piezoelectric composite plates. The proposed method incorporates Reddy's third-order shear deformation theory, Touratier's "Sine" model, Afaq's exponential model, Cho's higher-order zigzag laminate theory, as well as the classic plate theory and the first-order plate theory. Thus, the analysis can be conducted based on any of the above-mentioned theories. The selection of a specific method is done by simply changing a few terms in a 2 by 2 square matrix and the results, obtained according to different plate theories, can be compared to each other. Numerical examples are presented for piezoelectric composite plates subjected to mechanical loading. The results based on different shear deformation theories are compared with the three-dimensional solutions. The behaviours of piezoelectric composite plates with different length-to-thickness ratios, fibre orientations, and boundary conditions are also investigated in these examples.