• 제어로봇시스템학회논문지
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• 제14권7호
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• pp.720-725
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• 2008

This paper proposes a system architecture for USN with a service robot to provide more active assisted living services for elderly persons by monitoring their mental and physical well-being with USN environments at home, hospital, or silver town. Sensors embedded in USN are used to detect preventive measures for chronic disease. Logged data are transferred to main controller of a service robot via wireless channel in which the analysis of data is performed. For the purpose of handling emergency situations, it needs real-time processing on gathering variety sensor data, routing algorithms for sensor nodes to a moving sink node and processing of logged data. This paper realized multi-hop sensor network to detect user movements with biometric data transmission and performed algorithms on Xenomai, a real-time embedded Linux. To leverage active sensing, a mobile robot is used of which task was implemented with a priority to process urgent data came from the sink-node. This software architecture is anticipated to integrate sensing, communication and computing with real-time manner. In order to verify the usefulness of a proposed system, the performance of data transferring and processing on a real-time OS with non real-time OS is also evaluated.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제1권1호
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• pp.56-61
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• 2001

Activated sludge processes are broadly used in the biological wastewater treatment processes. The activated sludge processes are complex systems because of the many factors such as the variation of influent flowrate and ingredients, the complexity of biological reactions, and the various operation conditions. The main motivation o this research is to develop an intelligent control strategy for activated sludge process (ASP). ASP is a complex and nonlinear dynamic system owing to the characteristic of wastewater, the change in influent flowrate, weather conditions, and so on. The mathematical model of ASP also includes the uncertainty which is a ignored or unconsidered factor from process designers. The ASP model based on Matlabⓡ/Simulinkⓡ is developed in this paper. And the model performance is examined by IWA (International Water Association) and COST (European Cooperation in the filed of Scientific and Technical Research) data. The model tests derive steady-state results of 14 days. In this paper, fuzzy logic control approach is applied to handle DO concentrations. The fuzzy logic controller includes two inputs and one output to adjust air flowrate. The objective function for the optimization, in the implemented evolutionary strategy, is formed with focusing on improving the effluent quality and reducing the operating cost.

• 전력전자학회논문지
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• 제18권2호
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• pp.153-160
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• 2013

This research paper describes the development of battery charger with a variable output voltage capacity for charging the batteries used in electrical vehicles. The voltage and current accordingly is control via the buck converter that receives three phase current at primary side and fed to bridge rectifier which is comprised of full bridge converter and HFTR(High Frequency Transformer) for isolation and a square wave AC output. The transformer primary side is in series to divide certain charging current and the secondary side is comprised of six fix transformers so that they can generate certain amount of power and various output voltage through relay connection using 6 DC outputs. Moreover, all parallel connected full bridge serial resonant converter communicate together with upper(main) controller. The constructed structure is verified by conducting the test on PSIM as well as experimentally.

• 한국생산제조학회지
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• 제7권4호
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• pp.96-103
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• 1998

With the advance of processing technology , so as to spare fuel, piston heads used in automobile reciprocating engine have complex 3-dimension, with respect to shape such as ovality, profile, eccentricity, offset, recess. Therefore, coming out of the existing process work used master cam. the process work is performed using a CNC lathe. For a precision processing, the processing work is need to make study of high speed feed gear synchronized with the rotative speed of main spindle. And then the high speed feeding system must maintain high dynamic stiffness, high speed and high positioning accuracy . In this paper, in order to achieve high speed cutting tool feeding. The linear brushless DC motor is used for satisfying this process work. The ball bush and turicite is used as the guidance of the feed gear system. Also linear encoders, digital servo amplifiers and controller are used for controlling driving motor. This paper presents the design and simulation of the new tool feed system for noncircular machining.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2001년도 춘계학술대회논문집
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• pp.892-896
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• 2001

백색잡음 불규칙 과정으로 모델링된 난류형태의 유체운동에 의하여 가진되는 비선형 시스템의 특성과 제어기법에 대해 연구하였다. 고려된 물리적인 모델은 주질량과 끝단 집중질량을 갖는 보형태의 구조물이다. 그 지배방정식은 확률론적 관점에서 F-P-K 접근법으로 유도되었고, 비선형 해석법으로 Gaussian Closure방법을 이용하였다. 비선형 시스템의 제어기법으로는 슬라이딩 모드 제어기를 최초로 확률영역에서 설계하고 그 효과를 확률영역 및 시간영역에서 고찰하였다.

• 혜화의학회지
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• 제11권1호
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• pp.73-83
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• 2002

This thesis was written in order to help set groundwork of the mutuality between brain hormon and Shin-myung(神明) activity. 1. Shin-myung(神明) means all spritual functions, and Shin(神) represents thinking, myung(明) represents consciounsness. 2. As a origin of Shin-myung(神明) activity, in ancient times Heart(心) was regared as one, but since Chung-Dynasty(淸朝), Brain(腦) is regared as a main controller to manage Shin(神) in human body. 3. Shin-myung(神明) activity would should between Brain(腦) and Shin-Sin(心神) 4. Hormon is chemical substance to serve convey infomations and stimuiate them. In Present day Western medical science, make an attempt to understand Shin-myung(神明) activity of Brain(腦) as a activity of hormon doings. In conculusion, Shin-myung(神明) represent that Brain(腦) inculde Mind-Sprit(精神) activety, and it can be able by the function of brain hormon activety.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제10권1호
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• pp.95-105
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• 2006

기계적인 동작에 기반을 둔 디스크의 동작 특성 때문에 디스크의 속도는 처리기에 비하여 매우 느리다. 반도체기술의 발전으로 처리기의 속도 향상이 비약적으로 이루어지는 반면 디스크의 속도향상은 기계적인 동작특성 때문에 속도향상이 매우 제한적으로 이루어지고 있다. 따라서 컴퓨터시스템 전체의 성능향상을 이루이기 위하여 병목현상을 일으키는 디스크 입출력시스템의 성능을 개선할 수 있는 연구가 필수적이다. 처리기와 I/O subsystem의 속도차이를 해결하기 위한 하나의 기법으로 버퍼 캐시와 디스크 캐시를 두는 기법들이 사용되고 있다. 본 논문에서는 버퍼캐시와 디스크 캐시사이에 디스크 블록 중복을 제한하고, 재 참조 될 가능성이 높은 디스크 블록을 오랫동안 캐시에 유지하게 함으로 캐시 hit ratio를 높여 디스크 접근을 줄이고 신속하게 처리기에 디스크 블록을 서비스하여 시스템의 성능을 개선하는 효율적인 버퍼 캐시 및 디스크 캐시 관리기법을 제안하였고 시뮬레이션을 통하여 제안된 기법의 성능을 평가하였다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 2004년도 제5회 압연심포지엄 신 시장 개척을 위한 압연기술
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• pp.126-133
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• 2004

Lots of researches and applications on the automated overhead cranes in shops have been done for some decades, but a few successful results are reported. Integrated crane control systems designed by famous engineering companies are still expensive and are not satisfactory in view of maintenance and reliability. A more reasonable control system fit to requirements of manufacturing industries is suggested in the study. The new deigned system has superior capabilities for anti-sway of rope and position control. The controller for automated operations is composed of a Linux-based PC for non real-time control and a high-speed PLC for hard real-time control. Some algorithms required for coil yard operations as well as main control algorithms such as reference position generation, position control and anti-sway control have been designed and fully tested on the new crane simulator. The designed crane control system showed satisfactory performance on position control accuracy and anti-sway of rope. The maximum positional error is 8mm and the maximum sway error is 0.1 degrees. The suggested control strategies have been successfully applied to the 10-1 crane in No. 4 CGL of in the Kwangyang Steel Works and in commercial operation.

• 제어로봇시스템학회논문지
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• 제13권8호
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• pp.810-816
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• 2007

A security robot system named EGIS-SR is a mobile security robot through one of the new growth engine project in robotic industries. It allows home surveillance through an autonomous mobile platform using onboard cameras and wireless security sensors. EGIS-SR has many sensors to allow autonomous navigation, hierarchical control architecture to handle lots of situations in monitoring home surveillance and mighty networks to achieve unmanned security services. EGIS-SR is tightly coupled with a networked security environment, where the information of the robot is remotely connected with the remote cockpit and patrol man. It achieved an intelligent unmanned security service. The robot is a two-wheeled mobile robot and has casters and suspension to overcome a doorsill. The dynamic motion is verified through $ADAMS^{TM}$ simulation. For the main controller, PXA270 based hardware platform based on linux kernel 2.6 is developed. In the linux platform, data handling for various sensors and the localization algorithm are performed. Also, a local path planning algorithm for object avoidance with ultrasonic sensors and localization using $StarGazer^{TM}$ is developed. Finally, for the automatic charging, a docking algorithm with infrared ray system is implemented.

• Journal of Electrical Engineering and Technology
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• 제10권3호
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• pp.1335-1341
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• 2015

The utilization of electric vehicles has been suggested to support the frequency regulation of power system. Assuming that an intermediate aggregator exists, this study suggests a decentralized vehicle-to-grid operation scheme in which each vehicle-to-grid aggregator can behave independently of the power system operator. To implement this type of decentralized operation, this study adopts a price-based operation that has been proposed by many researches as an alternative operation scheme for the power system. In this environment, each vehicle-to-grid aggregator can determine its participation in vehicle-to-grid service in consideration of its residual energy of aggregated system and real-time market price. Consequently, the main purpose of this study is to verify whether or not the vehicle-to-grid power can effectively support the current frequency regulation function within the price-based operation scheme. Specifically, a frequency regulation method is proposed based on the real-time price signal, and a feedback controller for battery management is designed for decentralized vehicle-to-grid operation.