• Journal of the Korean Society of Safety
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• v.29 no.5
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• pp.47-53
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• 2014

Despite the automatic fire alarm system, according to the national fire data system of national emergency management agency, the fires account for 40,932 incidents, 2,184 injuries and about 430 billion won in property losses in 2013. Since the conventional automatic fire alarm system has several weaknesses related to electrical signal such as noise, surge, lighting, etc. Most fires are mainly caused by electrical faults, mechanical problem, chemical, carelessness and natural. The electrical faults such as line to ground fault, line to line fault, electrical leakage and arc are one of the major problems in fire. This paper describes the development of a novel real-time fire monitoring system algorithm including fault detection function which puts the existing optic smoke and heat detectors for fire detection with current and voltage sensors in order to utility fault monitoring using high accuracy DAQ measurement system with LabVIEW program. The fire detection and electrical fault monitoring with a proposed a new detection algorithm are implemented under several test. The fire detection and monitoring system operates according to the proposed algorithm well.

• Smart Media Journal
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• v.6 no.3
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• pp.95-102
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• 2017

A large volume of research has been devoted to the development of security tools for protecting the Smart Grid systems, however the most of them have not taken the Availability, Integrity, Confidentiality (AIC) security triad model, not like CIA triad model in traditional Information Technology (IT) systems, into account the security measures for the electricity control systems. Thus, this study would propose a novel security framework, an abnormal behavior detection system, to maximize the availability of the control systems by considering a unique set of characteristics of the systems.

• Journal of the Korea Society of Computer and Information
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• v.24 no.1
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• pp.129-135
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• 2019

This paper is part of research and development for stand-alone solar system without commercial power supply. It implements firmware of controller for operation of stand-alone solar system by applying IoT technology and also develops communication modules that allow multiple solar lamps to send and receive data through wireless network. The controller of the developed stand-alone solar system can effectively charge the power generated by the solar module, taking into account the battery's charge and discharge characteristics. It also has the advantage of attaching wireless communication modules to solar lamp posts to establish wireless communication networks without incurring communication costs. In addition, by establishing IoT gateway middleware platform for each installation site, it forms a foundation to operate multiple solar lamp posts into multiple clusters. And, it is expected that the data collected in each cluster will be used to enable configuration and control of operational information, thereby inducing convenience and efficiency of remote operation and management.

• Journal of Mechanical Science and Technology
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• v.18 no.12
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• pp.2069-2079
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• 2004

This paper represents the description of a complex mathematical model of biomechanical interaction for human-rifle system during shooting. The model is developed by finite element method using bar elements. And three typical shooting positions, i.e. standing, kneeling and prone are used. Characteristics of interior/exterior ballistics and behaviors of human-rifle system are evaluated by this model, which takes into account the influence of environment, bullet, powder, barrel geometry parameters and anthropological parameters. The results of this study can be applied to anthropology, biomechanics, medical science, gait analysis, interior ballistics and exterior ballistics.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.8
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• pp.1383-1391
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• 2016

This paper is concerned with applicability of a new type of controllers, called i-PID and GPI in which unknown parts of the plant are taken into account without any modeling procedure, to automatic voltage regulator (AVR) system. First, the procedure for applying i-PID and GPI algorithms to AVR system is proposed, which uses model reduction technique based on the given information of AVR. Second, simulations are given to verify their effectiveness comparing to various PID algorithms including PIDD2 which is four-term controller, that is, consisting of PID and second order derivative terms. Superior response performances of i-PID and GPI in comparison to conventional PID controllers are shown. Moreover, i-PID can highly improve the system robustness with respect to model uncertainties, especially to load variations.

• Kyungpook Mathematical Journal
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• v.60 no.2
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• pp.335-347
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• 2020

In this paper, we take into account a parasite-host system with reaction-diffusion. Firstly, we derive conditions for Hopf, Turing, and wave bifurcations of the system in the spatial domain by means of linear stability and bifurcation analysis. Secondly, we display numerical simulations in order to investigate Turing pattern formation. In fact, the numerical simulation discloses that typical Turing patterns, such as spotted, spot-stripelike mixtures and stripelike patterns, can be formed. In this study, we show that typical Turing patterns, which are well known in predator-prey systems ([7, 18, 25]), can be observed in a parasite-host system as well.

• Nuclear Engineering and Technology
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• v.29 no.4
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• pp.280-290
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• 1997

The robust controller for the nuclear reactor power control system is designed. The nuclear reactor is modeled by use of the point kinetics equations and the singly lumped energy balance equations, Since the model is not exact, the controller which can make the actual system robust is necessary. The perturbed plant is investigated by employing the uncertainties of the initial power level and the physical properties, and by introducing the delay into the modeled plant The overall system is configured into the two port model and the H$\infty$ controller is designed. In designing the H$\infty$ controller, two factors of the loop shaping and the permissible magnitude of control input are taken into account The designed controller provides the sufficient margins for the robustness, and the transients of the system output power and the control input satisfy their associated requirement.

• Journal of Electrical Engineering and Technology
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• v.10 no.2
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• pp.688-698
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• 2015

This paper presents a modeling and a controller design for a hybrid wind turbine generator, especially with an operating mode of battery energy-storage system and a dumpload that contribute to the frequency control of the system while diesel-synchronous unit is not in operation. The proposed control scheme is based on a robust tracking controller, which takes an account of system uncertainties due to the wind flow and load variations. In order to provide robustness for system uncertainties, the range of operation is partitioned into three operating conditions as sub-models in the controller design. In the simulation study, the proposed robust tracking controller (RTC) is compared with the conventional proportional-integral (PI) controller. Simulation results show that the effectiveness of the RTC against disturbances caused by wind speed and load variation. Thus, better quality of the hybrid wind power system is achieved.

• Journal of the Korean Society of Safety
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• v.33 no.2
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• pp.61-67
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• 2018

This study proposes a new vibration control approach for adjacent twin structures, which is termed as viscous damper asymmetric coupling system in this paper. The proposed system takes a concept that the diagonal bracing viscous dampers are asymmetrically distributed in two buildings to break the behavior symmetry of the twin buildings and then the coupling viscous damper is additionally installed at the top floor of the two buildings to couple both buildings and interactively transfer the asymmetric behavior-caused damping forces into both buildings. These asymmetric damping distributions and interacting damping forces of the connection damper efficiently suppress the overall vibration of the damper-coupled adjacent twin buildings efficiently. Genetic algorithm (GA) based multi-objective optimization technique is adopted for optimal design of the proposed system. In the numerical example of adjacent twin 10-story building structures, the conventional control approach, that is, uniform damping distribution system (UDS) is also taken into account for comparison purpose. The optimization results verify that the proposed system either can improve the control performance over the UDS with the same damping capacity, or can save the damping capacity significantly while maintaining the similar level of control performance to the UDS.

• Proceedings of the Korea Technology Innovation Society Conference
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• 1998.05a
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• pp.4-4
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• 1998

As our society leads into information age, it becomes necessary to build a new national science & technology information system responded to new social technological change. Therefore, It is needed a picture of the new economic structure to introduce a new system, but our part of science & technology information service have not taken into account of it. This paper gives the national R&D electronic information service system of science & technology in this new change a guide to the coming structure, thus allowing it to better define and position its offerings in the context of one another. The premise of this paper is that new role of it will be based on the structure of new national science & technology information system In this research results, information society of the future is going to the direction of maximizing the economies of extent and connection. The intent of Science & Technology Integrated Information System is hold the information in common, to possess accumulation benefit of the information. In this system, science & technology information fulfill its function of a R&D part in national management system, therefore cooperation among enterprise, school and research institution is easily made through the process into more enhancing the total competition of national science & technology.