• Journal of Institute of Control, Robotics and Systems
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• v.15 no.2
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• pp.198-202
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• 2009

Urban Search and Rescue (USAR) involves locating, rescuing (extricating), and medically stabilizing victims trapped in confined spaces. In this paper we state the current approach to USAR, address the limitations and discuss the way for moving in rugged topography. To achieve objectives such as surveillance, reconnaissance, and rescue, it is necessary to develop a driving mechanism that can handle rugged geographical features. We propose a new type of driving mechanism for a rescue robot that has a variable shape single-track. By using a variety shapes, it can get the gain of steering and rotating and the ability to overcome stairs. In this paper, we analyzed the design parameters for making variable transform shapes and determined the specifications of the robot to enhance adaptability to stairs.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.50 no.4
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• pp.177-183
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• 2001

In this paper, a new variable structure controller is designed for the tracker control of uncertain general plants so that the output of plants can controlled to a given arbitrary point in state space. By using the error between the steady state value of the output and the given reference, the sliding surface is defined, in advance, the surface from an initial state to the given reference without any reaching phase. A corresponding control input to satisfy the existence condition of the sliding mode is suggested to control the output on the predefined surface. Therefore the output controlled by the proposed controller is completely robust and identical to that of the sliding surface. Through an example, the usefulness is verified.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.59 no.11
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• pp.2066-2072
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• 2010

In this paper, a variable structure dynamic output feedback controller with an transformed sliding surface is designed for the improved robust control of a uncertain system under unmatched system uncertainty, matched input matrix uncertainty, and disturbance satisfying some conditions. This paper is extended from the results of the static output feedback VSS in [9]. To effectively remove the reaching phase problems, an initial condition of the dynamic output is determined. The previous some limitations on the dynamic output feedback variable structure controller is overcome in this systematic design. A stabilizing control is designed to generate the sliding mode on the predetermined sliding surface S=0 and as a results the closed loop exponential stability is obtained and proved together with the existence condition of the sliding mode on S=0 for all unmatched system matrix uncertainties. To show the usefulness of the algorithm, a design example and computer simulations are presented.

• Proceedings of the KIPE Conference
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• 2015.11a
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• pp.181-182
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• 2015

QZSI(Quasi Z-Source Inverter)를 이용한 유도전동기 제어시스템은 암단락 상태를 제어에 이용할 수 있어서 추가 컨버터 없이도 단일 구조로 가변 배터리 전압을 일정하게 승압할 수있다. 암단락을 이용한 승압은 직류단 전압제어가 보장되어야 하며 전압 제어기 성능이 인버터 출력 전류 제어에 상당한 영향을 미친다. 본 논문은 QZSI에서 직류 전압을 승압시키기 위한 암단락 시간을 효율적으로 제어하기 위한 변형 공간벡터방식을 이용하여 유도 전동기를 제어하고 시뮬레이션과 실험을 통해 이를 검증한다.

• Convergence Security Journal
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• v.13 no.3
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• pp.17-23
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• 2013

Clustering is required to configure clustering interdependent structural technology. Clustering handles variable workloads or impede continuity of service to continue operating in the event of a failure. Long as high-availability clustering feature focuses on server operating systems. Active-standby state of two systems when the active server fails, all services are running on the standby server, it takes the service. This function switching or switchover is called failover. Long as high-availability clustering feature focuses on server operating systems. The cluster node that is running on multiple systems and services have to duplicate each other so you can keep track of. In the event of a node failure within a few seconds the second node, the node shall perform the duties broken. Structure for high-availability clustering efficiency should be measured. System performance of infrastructure systems performance, latency, response time, CPU load factor(CPU utilization), CPU processes on the system (system process) channels are represented.

• Journal of Aerospace System Engineering
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• v.11 no.6
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• pp.26-33
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• 2017

We propose a variable frame structure connected with telescopic mast-shaped shaft for a robot displaying outstanding ability to cross obstacles, and for effective traction control. The wireless control system was built to extend and contract a deployable mechanism, which is shaped into a hoberman sphere assembled with frame structures. In order to develop important parameters for efficient locomotion, we derived an Euler-Lagrange equation for the spherical robot. According to the equation, the DC motor was selected. A prototype mechanism was tested and a Finite-Element Analysis (FEA) was conducted in parallel. Using these data, we constructed a deployable spherical robot with structural stability. The deployable robot moved at a speed of 0.85 m/s from 520 mm to 650 mm.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.1186-1191
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• 2007

The study uses the crossed wide girder(waffle slab type) in apartment structural system comparing with existing shear wall system. The crossed wide girder will be able to secure the span of the longest which is possible with minimum slab thickness by not increasing the height. The research sees continuity arranges the crossed wide girder in schedule interval following the stress distribution. Namely, it is to make the interior space with the space without column and wall in the minimum height. In order to check the numerical value of this study which it interpreted the ductile frame system due to the crossed wide girder and existing shear wall system used the Midas Gen is a program which 3-dimension laterial force designs are possible. Analysis results, the crossed wide girder system is not disadvantageously laterial drift, drift ratio and deflection of slab compares with existing shear wall system. Also the whole concrete amount is similar existing shear wall system. The crossed wide girder is advantage which secure a architectal variability.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.10 no.6
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• pp.31-37
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• 2010

In this paper, a performance of a decorrelating detector for a multirate MC(multi-carrier) DS/CDMA system is analyzed and simulated in a frequency selective Rayleigh fading channel. The performance is compared with that of single rate MC-DS/CDMA system in term of bit error probability. Variable Spreading Length (VSL) is employed for MC-DS/CDMA system as multirate transmission scheme. From simulation result, it is shown that Decorrelator for multirate MC-DS/CDMA achieves high BER performance as well as that of single rate case.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.760-765
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• 1992

In this paper, robust adaptive control algorithms which can be applied to unknown uncertain systems are suggested. Transform matrix for dividing states into "uncontrolled" states and "controlled" states and general searching procedure for the transform matrix which assign arbitrary n-1 eigen values for the uncontrolled subsystem of n-th order single-input single-output systems is also studied and utilized for the design of new-type controllers. We derived new-type control laws by using adaptive control theory and variable structure system and its stability is proved by using Lyapunov stability theory. From computer simulation results, we can see that the proposed adaptive control algorithm is robust and stable.s robust and stable.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.7A
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• pp.659-667
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• 2002

In this dissertation, in the Turbo Code used for error correction coding of the recent digital communication systems, we propose a new S-R interleaver that has the better performance than the existing block interleaver, and the Turbo Decoder that has the parallel concatenated New structure using the MAP algorithm. For real-time voice and video services over the third generation mobile communications, the performance of two proposed methods is analyzed by the reduced decoding delay using the variable decoding method by computer simulation over multipath channels of DS-CDMA system. Also, a Modified NCMA based on conventional NCMA is proposed to improve the channel efficiency in the mobile communication system, and is investigated over the multi-user environment of DS-CDMA system through computer simulation.