• International Journal of Fuzzy Logic and Intelligent Systems
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• v.6 no.2
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• pp.127-137
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• 2006

This paper presents an $H_{\infty}$ controller synthesis method for discrete time fuzzy dynamic systems based on a piecewise smooth Lyapunov function. The basic idea of the proposed approach is to construct controllers for the fuzzy dynamic systems in such a way that a Piecewise smooth Lyapunov function can be used to establish the global stability with $H_{\infty}$ performance of the resulting closed loop fuzzy control systems. It is shown that the control laws can be obtained by solving a set of Bilinear Matrix Inequalities (BMIs). An example is given to illustrate the application of the proposed method.

• Convergence Security Journal
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• v.24 no.3
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• pp.219-229
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• 2024

The application of 4th Industrial Revolution technologies in the defense sector is accelerating, leading to the rapid incorporation of information and communication technologies (ICT) into military systems. The biggest threat to these ICT-based military systems is an electromagnetic pulse (EMP) attack, which can result from nuclear explosions or EMP bombs. North Korea's ongoing nuclear advancements and EMP bomb capabilities pose a critical threat, necessitating South Korea's preparedness for such attacks to ensure the effective operation of its ICT-based military systems. Despite this urgency, the South Korean military currently lacks comprehensive standards for EMP protection, relying only on the design criteria for EMP protection facilities for buildings. This gap highlights the absence of sufficient legal and regulatory measures and the lack of focused research to develop EMP protection performance standards for safeguarding military systems. Therefore, this paper aims to analyze existing EMP protection performance standards and relevant laws and regulations. It proposes improvements and establishes necessary standards to enhance the EMP resilience of military facilities and equipment.

• Journal of Mechanical Science and Technology
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• v.15 no.1
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• pp.125-138
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• 2001

An efficient correction storage scheme on a structured grid is applied to a sequence of approximate Jacobian systems arising at each time step from a linearization of the discrete nonlenear system of equations, obtained by the implicit time discretization of the conservation laws for unsteady fluid flows. The contribution of freezing the Jacobian matrix to computing costs is investigated within the correction storage scheme. The performance of the procedure is exhibited by measuring CPU time required to obtain a fully developed laminar vortex shedding flow past a circular cylinder, and is compared with that of a collective iterative method on a single grid. In addition, some computed results of the flow are presented in terms of some functionals along with measured data. The computational test shows that the computing costs may be saved in favor of the correction storage scheme with the frozen Jacobian matrix, to a great extent.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.102-102
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• 2000

In this paper, attitude control laws are proposed for an underactuated spacecraft. The stabilization problem of the complete system including the kinematics as well as the dynamics of the spacecraft is addressed. The quaternion parameterization is used. The key idea is that the angular velocity of a uncontrolled axis is first regulated and then, the other states are regulated. Based on numerical simulations, it is conjectured that the closed-loop nonlinear system of a spacecraft with the proposed control laws is globally asymptotically stable. The control law for the stabilization problem around the origin as well as the command following problem are proposed. The numerical examples indicate that the stabilization of an underactuated asymmetric spacecraft can be achieved successfully.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2308-2310
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• 2001

In the adaptive fuzzy sliding mode control, from a set of a fuzzy IF-THEN rules adaptive fuzzy sliding mode control whose parameters are adjusted on-line according to some adaptation laws is constructed for the purpose of controlling the plant to track a desired trajectory. Most of the research works in nonlinear controller design using fuzzy systems consider the affine system with fixed grid-rule structure based on system state availability. The fixed grid-rule structure makes the order of the controller big unnecessarily, hence the on-line fuzzy rule structure and fuzzy observer based adaptive fuzzy sliding mode controller is proposed to solve system state availability problems. Therefore, adaptive laws of fuzzy parameters for state observer and fuzzy rule structure are established implying whole system stability in the sense of Lyapunov.

• Journal of Information Management
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• v.40 no.4
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• pp.135-150
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• 2009

Existing bibliometric laws have been established on the basis of well defined science journals with a long history. However, the history of technology innovation research in Korea is young and the scope of the research is diverse compared with other fields. The main purpose of this research can be summarized as follows : Can the traditional bibliometric laws be used to explain the young and diverse data derived from technology innovation studies in Korea. Second, we want to compare the explain ability of the power law, compared with the traditional laws in the field. Third, we propose a quasi index related to the well-known impact factor to measure the contribution of a journal or a group of journals to the development of innovation research in Korea. We confirmed Lotka's and Bradford's laws which are used to measure the productivity of researchers, but we could not support the validity of Price's Square Root law as Nicholls (1998) could not. On the citations to journals, Garfield's laws is not observed. However, the power law fits well the citations to author, journal, article, and book. The estimated parameters between 1.6 and 3.5 are similar to the values in the range of 1.5 and 3 in previous studies. Finally the quasi index shows that the influence of international leading journals on innovation research in Korea is weaker than on innovation studies in the world.

• Korean Journal of Geomatics
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• v.2 no.1
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• pp.75-82
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• 2002

The information system fields of spatial applications have rapidly grown during the last decade in Korea. Spatial data has been produced for a variety of systems without common standards until national GIS Committee defined the data exchange formats among spatial databases in the middle of 1990's. It aimed at promoting data sharing between the different systems in similar application fields. However, a considerable number of databases built prior to the introduction of the standards are not yet standard compliant but still play the roles of the main producers/consumers in the data collection field such as early developed huge AM/FM systems maintained by governmental organizations. The strong autonomy of these databases keeps their own data models, formats and descriptions from being standardized, which leads the sharing to a more difficult stage. Sharing is another way of data acquisition with least efforts and time away from direct collection. A data clearinghouse is the core module which directs users to the relevant data resources. The contents of datasets should be described with predefined metadata standards for precise indexing. Moreover, a number of technical problems have to be resolved for the common use of data between heterogeneous spatial database systems. However, the technical issues can be covered by the present information technologies. The difficulties persist in the political/institutional issues. Institutional issues are derived from the diverse sources such as political background, governmental policies, related laws and/or regulations. The paper will firstly make an analysis of current situation in terms of Korean policies, laws and regulations, secondly abstract the institutional issues from the situation analysis, lastly present guidelines for promoting spatial data sharing in Korea.

• The Journal of Fisheries Business Administration
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• v.31 no.2
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• pp.119-132
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• 2000

One of most important wort to build Fisheries Policy Information Systems(FPIS) is related to connect the data warehouse between fisheries departments, This paper presents the developing strategies to build the FPIS. First, developing the FPIS needs to compensate the laws and regulations with assistance of fisheries departments. Second, FPIS developer needs to cooperate the related fisheries departments deeply, Third, developing the data warehouse will be contribute to improve criterion and statistics of fisheries data. Forth, For experts of systems use the FPIS, they are needed to educate for appling the systems in the fisheries environments.

• International Journal of Control, Automation, and Systems
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• v.2 no.1
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• pp.1-14
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• 2004

This paper surveys some existing direct adaptive feedback control schemes for linear time-invariant systems with actuator failures characterized by the failure pattern that some inputs are stuck at some unknown fixed or varying values at unknown time instants, and applications of those schemes to aircraft flight control system models. Controller structures, plant-model matching conditions, and adaptive laws to update controller parameters are investigated for the following cases for continuous-time systems: state tracking using state feed-back, output tracking using state feedback, and output tracking using output feedback. In addition, a discrete-time output tracking design using output feedback is presented. Robustness of this design with respect to unmodeled dynamics and disturbances is addressed using a modified robust adaptive law.

• Management & Information Systems Review
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• v.7
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• pp.69-92
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• 2001

The purpose of this study is to show the problems and to suggest improvement methods on the introduction of Pharmacy Information Systems(PIS) after medical reform. Medical reform have influenced many aspects of patients, doctors and pharmacists. In the case of pharmacy, information systems have been key role in the pharmacy management after medical reform. Although one year has been passed, there are still many problems. The size of system development company, A/S, the ability of programmer and the frequent change of related laws and ordinances cause difficulties in the operation of PIS. In this paper, the case of A pharmacy in daegu was investigated for the operation of PIS. Analytic Hierarchy Process(AHP) and mathematical programming methods can be used for reducing the aspect of subjectivity and considering the resource constraints.