• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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• pp.799-802
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• 1997

This paper deals with a new method to derive the Generalized Jacobian Matrix of a space robot. In a conventional method to derive the Generalized Jacobian Matrix, generalized coordinates select Joint angles and a space robot body's position and attitude angle. But, in this paper, we select position and attitude angle of the end-effector or the handled floating object as generalized coordinates. Then, we can derive the Generalized Jacobian Matrix of the system which consists of several space robots and a handled floating object. Moreover control methods operated by only one space robot can be easily extended to the cases of cooperation task by several space robots. Computer simulations show that the Generalized Jacobian Matrix derived here is effective.

• 천문학회보
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• 제43권1호
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• pp.68.4-69
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• 2018

GMACS is one of the instruments for the Giant Magellan Telescope (GMT) which will provide wide field, multi-object, moderate resolution spectroscopy of faint targets. KHU (Kyung Hee University) is in charge of control software of GMACS. As a first step, the Slit Mask Exchange Mechanism Prototype (SMEM-P) will be used as a preliminary example to make development process between electronics and high level software. Recently, we have developed a sample program to communicate with low level devices via EtherCAT. It is expected to be a mockup design for software and control system of GMACS. In this poster, we show the development process and test operation results of control software for SMEM-P.

• 제어로봇시스템학회논문지
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• 제15권4호
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• pp.365-371
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• 2009

A intelligent mobile hexapod robot with various types of sensors and wireless camera is introduced. We show this mobile robot can detect objects well by combining the results of active sensors and image processing algorithm. First, to detect objects, active sensors such as infrared rays sensors and supersonic waves sensors are employed together and calculates the distance in real time between the object and the robot using sensor's output. The difference between the measured value and calculated value is less than 5%. This paper suggests effective visual detecting system for moving objects with specified color and motion information. The proposed method includes the object extraction and definition process which uses color transformation and AWUPC computation to decide the existence of moving object. We add weighing values to each results from sensors and the camera. Final results are combined to only one value which represents the probability of an object in the limited distance. Sensor fusion technique improves the detection rate at least 7% higher than the technique using individual sensor.

• 컴퓨터교육학회논문지
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• 제5권4호
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• pp.79-89
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• 2002

기존의 고정 단발기 (PC)에서만 주로 행해지던 각종 다중 사용자 접속 온라인 응용이 최근 PC와 PDA, 휴대폰 등이 공동 작업을 수행하는 멀티 플랫폼 기반 온라인 응용으로 전환되고 있다. 그러나 지금까지 멀티 플랫폼 기반 온라인 응용은 다중 사용자의 공동 데이터의 동시 접근 및 각 클라이언트의 처리 능력과 통신 속도의 비대칭을 고려하지 않아 컨텐츠가 매우 단순한 실정이다. 이 논문에서는 멀티 플랫폼 기반 동시성 제어 기법, 다양한 클라이언트간의 변경 전파 프로토콜, 모바일 클라이언트의 특성을 고려한 객체 관리 기술을 제안하였다. 그리고 멀티 플랫폼 기반 채팅 프로그램을 제작하여 제안한 기법들이 적절히 동작함을 보였다.

• 전자통신동향분석
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• 제31권3호
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• pp.1-8
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• 2016

최근 개인화된 미디어의 출현과 더불어 방송통신 미디어 분야에서 개인별 맞춤형 방송 서비스에 대한 관심과 지원이 빠르게 확산되는 추세다. 특히, 다중 카메라를 이용한 관심 인물에 대한 다각도 영상과 같은 차별화된 영상을 제공하려는 수요가 꾸준히 증가하고 있다. 객체 중심의 영상을 생성하기 위한 관련 기술의 발전 및 수요 변화에 발맞춰 본고에서는 관련 기술의 개요 및 연구동향을 살펴보고, ETRI에서 개발 중인 객체 추적 기반의 다중 Pan-Tilt-Zoom(PTZ) 카메라 제어를 통한 객체 중심 다각도 영상 획득 기술을 소개하고자 한다.

• 한국지능시스템학회:학술대회논문집
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• 한국퍼지및지능시스템학회 2001년도 추계학술대회 학술발표 논문집
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• pp.177-180
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• 2001

The subject of this paper is to efficient Pm duty contort for two DC motor synchronousness in the system. Fuzzy controller have been successfully applied to many uncertain and complex industrial plant. So, It adapted fuzzy controller using compositional fuzzy rule so that change PH duty for speed control if the length of destination is different, And for unknow plant, it is the study to make the unknow transfer function system with fuzzy control method. This controller has been successfully applied to Pm duty control for the system synchronousness.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2003년도 춘계학술대회 논문집
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• pp.1755-1759
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• 2003

The hydraulic excavator has been a popular research object for automation because of its multi-workings and economic efficiency. The objective of this paper is to design each components and to construct boom, arm, bucket circuit. These models modeled with AMESim show us change of variables and behavior of excavator. Simulation model will be used for simulator of excavator.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제14권2호
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• pp.595-609
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• 2020

In this study, we propose a decentralized mathematical model for predictive control of a system of multi-autonomous unmanned aerial vehicles (UAVs), also known as drones. Being decentralized and autonomous implies that all members make their own decisions and fly depending on the dynamic information received from other unmanned aircraft in the area. We consider a variety of realistic characteristics, including time delay and communication locality. For this flocking flight, we do not possess control for central data processing or control over each UAV, as each UAV runs its collision avoidance algorithm by itself. The main contribution of this work is a mathematical model for stable group flight even in adverse weather conditions (e.g., heavy wind, rain, etc.) by adding Gaussian noise. Two of our proposed variance control algorithms are presented in this work. One is based on a simple biological imitation from statistical physical modeling, which mimics animal group behavior; the other is an algorithm for cooperatively tracking an object, which aligns the velocities of neighboring agents corresponding to each other. We demonstrate the stability of the control algorithm and its applicability in autonomous multi-drone systems using numerical simulations.

• 제어로봇시스템학회논문지
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• 제13권11호
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• pp.1074-1081
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• 2007

This paper presents a method for real-time face detection and tracking which combined Adaboost and Camshift algorithm. Adaboost algorithm is a method which selects an important feature called weak classifier among many possible image features by tuning weight of each feature from learning candidates. Even though excellent performance extracting the object, computing time of the algorithm is very high with window size of multi-scale to search image region. So direct application of the method is not easy for real-time tasks such as multi-task OS, robot, and mobile environment. But CAMshift method is an improvement of Mean-shift algorithm for the video streaming environment and track the interesting object at high speed based on hue value of the target region. The detection efficiency of the method is not good for environment of dynamic illumination. We propose a combined method of Adaboost and CAMshift to improve the computing speed with good face detection performance. The method was proved for real image sequences including single and more faces.

• 한국정보보호학회:학술대회논문집
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• 한국정보보호학회 2001년도 종합학술발표회논문집
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• pp.340-347
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• 2001

MAC(Mandatory Access Control)이나 MLS(Multi Level Security) 보안정책이 적용된 보안운영체제는 주체와 객체에 보안등급(Security Level)과 영역(Category) 값을 부여하고, 부여된 이들 정보에 의해 객체에 행해지는 주체의 접근을 제한한다. 하지만, 이러한 MAC과 MLS 보안이 적용된 경우라 하더라도 시스템의 보안정책을 위반하며 불법적 정보를 유통하게 하는 경로가 있을 수 있다. 본 논문에서는 불법적 정보의 유통경로가 되고 있는 IPC(Inter Process Communication) 메커니즘과 스토리지에 의한 비밀채널을(Covert Channel) 문제 해결 위해 커널 수준의 설계와 구현을 시도하였다. IPC 메커니즘에 의한 불법적 정보흐름 제거를 위해 IPC 메커니즘에 MLS 보안정책을 적용하였고, 스토리지 비밀채널는 시스템 콜 명세를 분석하여 이를 식별, 감사, 지연처리가 가능토록 하였다.