• 제어로봇시스템학회:학술대회논문집
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• 2004.08a
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• pp.425-428
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• 2004

In this paper, we study the discretization behaviors of the equivalent control based sliding-mode control (SMC) systems. The investigation is carried out via studying the second order linear system and some interesting dynamic properties are explored. Especially, according to the variation of system parameters, the inherent dynamical behavior of the trajectories within some specified boundaries are studied. From this result, the boundaries of system state using symbolic dynamics approach are first proposed. Simulations are presented to verify the theoretical results.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.214-217
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• 2002

The chromosomes of Genetic Algorithm(GA) are classified to be good or not to be by Support vector machines(SVM), and then the only good chromosomes are adopted to the evolution process. By this way, computational load becomes low, so the evolution speed of Genetic Algorithm modified by SVM can be much accelerated than the conventional GA.

• Journal of Power Electronics
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• v.16 no.3
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• pp.1236-1243
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• 2016

This paper presents the analysis and design of an active electromagnetic interference (EMI) filter (AEF) for the common-mode (CM) noise reduction of switching power converters. The features of the several types of AEFs are discussed and compared in terms of implementation. The feed-forward AEF with a voltage-sensing and voltage-cancellation (VSVC) structure is implemented for an LLC resonant converter to replace a multiple-stage passive EMI filter and thereby reduce CM noise. The characteristics and performance of the VSVC-type AEF are investigated through theoretical and experimental works.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2283-2285
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• 2001

This paper proposed to a neural network based fuzzy control (neuro-fuzzy control) technique for attitude control of helicopter with strongly dynamic nonlinearities and derived a helicopter aerodynamic torque equation of helicopter and the force balance equation. A neuro-fuzzy system is a feedforward network that employs a back-propagation algorithm for learning purpose. A neuro-fuzzy system is used to identify nonlinear dynamic systems. Hence, this paper presents methods for the design of a neural network(NN) based fuzzy controller(that is, neuro-fuzzy control) for a helicopter of nonlinear MIMO systems. The proposed neuro-fuzzy control determined to a input-output membership function in fuzzy control and neural networks constructed to improve through learning of input-output membership functions determined in fuzzy control.

• Smart Media Journal
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• v.10 no.3
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• pp.54-59
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• 2021

Flight data acquired through flight instrumentation equipment during aircraft development play an important role in aircraft development and performance improvement. Therefore, as the reliability of flight instruments is required, inspection systems to check the soundness of flight instruments are very important. In this paper, we analyze the existing test system for flight data instrumentation equipment and present improvements in the hardware and software aspects of the test system. Based on this, we design and implement a test system with improved performance and present test results. Test system with improved performance improves cost savings, flexible application, and maintenance compared to the existing test system. Therefore, the robustness of the instrumentation equipment can be obtained, which can be expected to improve the reliability of flight data.

• Proceedings of the KIEE Conference
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• 1998.11b
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• pp.445-447
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• 1998

This paper shows simulation results for stability and performance of two INS/GPS integration systems. First, the code tracking error of GPS receiver is analyzed by spectrum analysis and simulated for the tight and loose INS/GPS integrations. Next, stability of the integrated systems are simulated using root locus method. As loop filter in the GPS receiver, passive filter and active filter are used and compared.

• Journal of Information Display
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• v.1 no.1
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• pp.52-58
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• 2000

We observed that static electricity has an influence on the etching unformity of dry etching process. When the static electricity was applied from-200[V]to-1000[V] on glass substrates, the etching rate uniformity was changed to 1.5%-15%. In this experiment, the soft X-ray to neutralize static electricity was adopted as ore of neutralization methods. As an experimental result, soft X-ray irradiation improved neutralization capability on the surface of LCD glass substrate within the short time, about 15-30sec. The difference of etching rate uniformity was below 0.5%.

• Proceedings of the KIEE Conference
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• 2002.11c
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• pp.454-456
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• 2002

Embedded system is used a lot in electric home appliances and home network equipment. However, this system is designed to operate by the system operator directly at home and operator could find out them only when he pays attention to the system in case event happens. In this paper, to improve above things, it designed to remote-control system anywhere in which internet access is possible as well as at home, and also it designed SMS(short message service) information transmission system to inform the errors to the operator when they happen. To design the system, development board(be included the Strong Arm), CDMA module, and electric door lock are used as hardware, and web browser, CGI(common gateway interface) programming, and C-language are used for implementation of software in embedded-linux platform.

• Proceedings of the KIEE Conference
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• 2001.07d
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• pp.2393-2395
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• 2001

The mobile robot is used as an instrument of transportation in automated plant. But the greater part of the moving method is the wheel-type. The wheel-type robot is easier control than the track-type, However the track-type is better than the wheel-type in bad landform(bend landform, an incline plane, stairs). In this paper, we propose the navigation algorithm of track-type robot in order to improve a defect of wheel-type. We experiment in bend landfrom and even ground to differentiate the navigation method. To estimate robot pose, we use the 80196 in a close distance and the vision-board in a long distance. Each data is managed in main PC and then the part of managing correspond to every sensor. We also use twelve supersonic wave-sensors to recognize external surroundings. As the result of experiment, we analyze the algorithm of control and make possible surroundings-adaptation.

• Journal of the Korean Society for Nondestructive Testing
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• v.35 no.3
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• pp.206-214
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• 2015

In this study, low-velocity impact damage (LVID) in glass fiber reinforced plastic (GFRP) was investigated using pulse thermography (PT) and lock-in thermography (LIT) techniques. The main objective of this study was to evaluate the detection performance of each technique for LVID in GFRP. Unidirectional and cross-ply GFRPs were prepared with four energy levels using a drop weight impact machine and they were inspected from the impact side, which may be common in actual service conditions. When the impacted side was used for both inspection and thermal loading, results showed that the suggested techniques were able to identify the LVID which is barely visible to the naked eye. However, they also include limitations that depend on the GFRP thickness at the location of the delamination produced by the lowest impact energy of five joule.