• Journal of Institute of Control, Robotics and Systems
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• v.10 no.2
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• pp.139-144
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• 2004

The flight control system designed for an unmanned airship, which is under development by KARI, is in reduced. First, the dynamic characteristics of the airship are addressed, which are fairly different from those of the nominal aircraft. In order to implement autonomous flight for the unmanned airship, flight control logic is designed including autopilot and guidance law. The autopilot is designed under consideration of the velocity region of the unmanned airship. The guidance laws are implemented in main operational modes such as point navigation, station keeping and spiral up/down for emergency return. Their simulation results are also presented in order to validate performances of the flight control system.

• Proceedings of the KIEE Conference
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• 2008.04a
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• pp.197-198
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• 2008

A software platform which is able to evaluate the performances of a GPS/INS integrated system has been developed in this paper. And it consists of four parts including GUI(Graphic User Interface) part, GPS part, INS part and integrated filter part. It basically offers the loosely, tightly and deeply coupled GPS/INS algorithms, and many design parameters can be changed by users via GUI. Each functions of the platform has been confirmed with GPS signals and IMU data from commercial simulators.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2009.11a
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• pp.155-155
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• 2009

This paper introduces the findings of a detailed study on breakdown voltage strength under DC voltage and the development of HVDC cable. Recently, Nano-fillers are attracting attentions of many researchers and engineers, since they seem to bring higher potentials for advancement of electrical insulating properties as nano-composites. Additives and fillers are often adopted to polymeric materials for improving insulating and machanical properties. We have improved the polymer composition and developed a new insulation material for HVDC cable. Each specimen blended at LDPE1 to antioxidant, LDPE2 to antioxidant, pure XLPE was manufactured respectively. The insulation performances of the proposed insulator were compared with specimens blended at nano powders. DC breakdown strength of LDPE1 specimen at 90[$^{\circ}C$] was higher than other specimens. The experimental results show that polar groups intorduced in moleculars chains of blended specimen plays an important role in enhancement of thermal conductivity.

• Journal of Institute of Control, Robotics and Systems
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• v.9 no.10
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• pp.816-821
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• 2003

In the manufacturing industries, agility and flexibility are the key issues to meet the various market demands. From this point of view, open architecture control has many advantages. This paper suggests a real-time Linux-based open architecture controller. Linux-based and windows-based controllers are compared in several aspects, and Linux is shown to be advantageous over the windows. With the user friendly GUI, the suggested controller is applied to the X-Y stage which is made of two linear motors. Path following and repeatability performances are successfully observed, which shows the validity of the suggested controller.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.268-271
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• 2004

This paper describes the development of a fuzzy logic control based on PID controller to improve the performances of the control system using conventional PID controller for the cascade process control systems. The structure of the proposed control system consists of two fuzzy-based PID controllers. One is used to eliminate the input disturbances of the inner loop and the other is used to regulate output response of the outer loop. The fuzzy PID design is derived from the linear-time continuous function of the conventional PID controller. The performance of the proposed controller is verified by MATLAB/SIMULINK simulation. Results of simulation studies demonstrates the outstanding of the control system using fuzzy-based PID controller in terms of reduced overshoot and fast response compared with the conventional PID controller.

• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.726-729
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• 2004

This paper concerns on developing a multi-purpose test device for measuring mechanical properties of shoes. The device was modified from a commercial robot manipulator, with which impact, bending, and pronation tests were suggested to evaluate performances of shoes. From several experiments, the developed device could produce repetitive and consistent results corresponding to the different material of shoes. In the shoe industry, it is expected that the device could contribute to developing a better shoe for comfort of costumers.

• Proceedings of the IEEK Conference
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• 2003.07c
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• pp.2943-2946
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• 2003

In this paper are described the indirect induction healed boiler and induction boated hot air producer using the voltage-fed series resonant high-frequency inverter which can operate in the frequency range from 20［kHz］to 50［kHz］. A specially designed induction heater, which is composed of laminated stainless assembly with many tiny holes and interconnected spot welding points between stainless plates, is inserted into the ceramic type vessel with external working coil. This working coil is connected to the inverter and turbulence fluid through this induction heater to moving fluid generates in the vessel. The operating performances of this unique appliance in next generation and its effectiveness are evaluated and discussed from a practical point of view.

• The Journal of the Acoustical Society of Korea
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• v.15 no.2E
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• pp.60-68
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• 1996

In this paper, we implement the door lock system based on pattern matching technique for speaker recognition using DTW. In this study, major features of our system are summarized as follows:(1) Make the average reference pattern using DTW. This method keeps the high recognition rate compared with the other systems whose performances degrade rapidly as time goes on. (2) Use F-ratio values of the cepstral coefficients. We find that the weighted cepstral reveals an effect on intensifying the difference between th customer and the imposter. The system hardware is composed of two parts : the door lock part and the speaker recognition processing part. We use an 8051 microprocessor in the door lock park for serial communication with host processor to open or close the lock. Using our system, we obtain speaker recognition rate of about 99.5%.

• KSII Transactions on Internet and Information Systems (TIIS)
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• v.7 no.5
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• pp.1108-1130
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• 2013

Wireless Body Area Networks (WBANs) are becoming increasingly important to solve the issue of health care. IEEE 802.15.6 is a wireless communication standard for WBANs, aiming to provide a real-time and continuous monitoring. In this paper, we present our development of a modified Markov Chain model and a backoff model, in which most features such as user priorities, contention windows, modulation and coding schemes (MCSs), and frozen states are taken into account. Then we calculate the normalized throughput and average access delay of IEEE 802.15.6 networks under saturation and ideal channel conditions. We make an evaluation of network performances by comparing with IEEE 802.15.4 and the results validate that IEEE 802.15.6 networks can provide high quality of service (QoS) for nodes with high priorities.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.9 no.2
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• pp.112-121
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• 1997

This study is focused on the development and selection of optimal cool tube system to maximize its thermal performance. Cool tube is devised to reduce the heating and cooling load of building by preheating or refreshing of intake air. Finite volume method was adopted to solve the conduction problem between the cool tube and earth. We examine the cool tube system for two operating periods, a short term(12 hours) and a long term(3 months). The results of short term operations reveal that condensation significantly influences and raises the exit air temperature. For long term operations, optimum conditions of cool tube system are obtained with variations of flow-rate, depth, length and diameter of cool tube.