• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 하계학술대회 논문집 D
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• pp.2420-2422
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• 2003

In this paper, two Fuzzy Logics for path planning of an autonomous mobile robot are proposed. If a target point is given, such problems regarding the velocity and object recognition are closely related with path to which the mobile robot navigates. Therefore, to ensure safety navigation of the mobile robot for two fuzzy logic parts, path planning considering the surrounding environment was performed in this paper. First, feature points for local and global path are determined by utilizing Cell Decomposition off-line computation. Second, the on-line robot using two Fuzzy Logics navigates around path when it tracks the feature points. We demonstrated optimized path planning only for local path using object recognition fuzzy logic corresponds to domestic situation. Furthermore, when navigating, the robot uses fuzzy logic for velocity and target angle. The proposed algorithms for path planning has been implemented and tested with pioneer-dxe mobile robot.

• Journal of Information Processing Systems
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• 제13권5호
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• pp.1410-1429
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• 2017

Mobility arises naturally in the Internet of Things networks, since the location of mobile objects, e.g., mobile agents, mobile software, mobile things, or users with wireless hardware, changes as they move. Tracking their current location is essential to mobile computing. To overcome the scalability problem, hierarchical architectures of location databases have been proposed. When location updates and lookups for mobile objects are localized, these architectures become effective. However, the network signaling costs and the execution number of database operations increase particularly when the scale of the architectures and the numbers of databases becomes large to accommodate a great number of objects. This disadvantage can be alleviated by a location caching scheme which exploits the spatial and temporal locality in location lookup. In this paper, we propose a hierarchical location caching scheme, which acclimates the existing location caching scheme to a hierarchical architecture of location databases. The performance analysis indicates that the adjustment of such thresholds has an impact on cost reduction in the proposed scheme.

• 인터넷정보학회논문지
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• 제9권3호
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• pp.25-41
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• 2008

본 논문에서는 유비쿼터스 컴퓨팅에서 모바일 협업 서비스를 위한 컴팩트 분산객체그룹 프레임워크(Compact Dostributed Object Group Frorework : CDOGF)에 대해 기술한다. CDOGF는 논리적인 영역에 따라 각 센서 및 기기의 네트워크 연결과 다수의 모바일 컴퓨팅 장치의 관리, 모바일 협업응용 서비스의 수행하는 객체들의 그룹화를 지원한다. 이를 위해, CDOGF의 구성요소의 세부적인 기능을 메소드와 이를 이용하기 위한 인터페이스를 설계하였다. 그리고 각 구성요소간의 상호작용을 센서와 응용, CDOGF와 응용, CDOGF 내부 구성요소간, CDOEF와 DOGF등 네 가지 형태로 구분하여 기술하였다. 또한 기존 모바일 협업을 위한 기술들의 분석하여 모바일 협업 환경을 정의하였다. 본 환경에서 모바일 협업 응용 서비스의 구현과 위에서 언급한 네 가지 상호연동을 위해 TMO 스킴과 분산 미들웨어인 TMOSM를 사용하였다. 끝으로 u-병원 응용을 본 환경에서 수행하도록 하였다. u-병원 응용은 유비쿼터스 환경을 갖춘 병실로부터 병실의 환경정보와 환자의 건강정보를 모바일 장치인 PDA를 통해 수집한다. 또한 환자관리 업무를 위한 정보 서비스를 제공한다.

• International Journal of Control, Automation, and Systems
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• 제1권4호
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• pp.495-502
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• 2003

This paper focuses on the implementation of an efficient tracking method of a moving object using optimal representative blocks by way of a pan-tilt camera. The key idea is derived from the fact that when the image size of a moving object is shrunk in an image frame according to the distance between the mobile robot camera and the object in motion, the tracking performance of a moving object can be improved by reducing the size of representative blocks according to the object image size. Motion estimations using Edge Detection (ED) and Block-Matching Algorithm (BMA) are regularly employed to track objects by vision sensors. However, these methods often neglect the real-time vision data since these schemes suffer from heavy computational load. In this paper, a representative block able to significantly reduce the amount of data to be computed, is defined and optimized by changing the size of representative blocks according to the size of the object in the image frame in order to improve tracking performance. The proposed algorithm is verified experimentally by using a two degree-of- freedom active camera mounted on a mobile robot.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2017년도 춘계학술대회
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• pp.297-299
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• 2017

최근 증강 현실(AR)의 응용분야가 급증하고 관련 콘텐츠 또한 수요가 증대되고 있다. 이와 같이 모바일 환경에서 AR 콘텐츠의 서비스를 위해서는 오브젝트 기반의 마커 인식 기능이 필요하다. 이때 마커에 대응하는 정보를 제공하기 위해 특정 마커에 대응하는 가상 오브젝트를 생성하여 서비스하는 기법을 사용한다. 그러나 마커에 대응하는 가상의 오브젝트를 AR 화면상에 유지할 때 카메라의 떨림, 카메라의 이동 등의 다양한 이유로 마커의 오브젝트가 불안정하게 흔들리는 현상이 발생된다. 이와 같이 모바일 디바이스 기반의 AR 서비스는 안정적으로 오브젝트를 표현하기 어렵다는 문제점을 갖는다. 본 논문에서는 모바일 AR 환경에서 고정된 마커를 인식했을 때, 디바이스의 물리적 상태 변화에 대응하는 필터링 방법을 적용하여 안정적인 마커 인식 및 추적 기법을 제안한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제4권3호
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• pp.358-379
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• 2010

Multiple object association is an important capability in visual surveillance system with multiple cameras. In this paper, we introduce locally initiating line-based object association with the parallel projection camera model, which can be applicable to the situation without the common (ground) plane. The parallel projection camera model supports the camera movement (i.e. panning, tilting and zooming) by using the simple table based compensation for non-ideal camera parameters. We propose the threshold distance based homographic line generation algorithm. This takes account of uncertain parameters such as transformation error, height uncertainty of objects and synchronization issue between cameras. Thus, the proposed algorithm associates multiple objects on demand in the surveillance system where the camera movement dynamically changes. We verify the proposed method with actual image frames. Finally, we discuss the strategy to improve the association performance by using the temporal and spatial redundancy.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2005년도 ICCAS
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• pp.1887-1891
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• 2005

Despite significant advances in multimedia transferring technologies in various fields of robotics, it is sometimes quite difficult for the operator to fully understand the context of 3D remote environments from 2D image feedback. Particularly, in the remote control of mobile robots, the recognition of the object associated with the task is very important, because the operator has to control the robot safely in various situations not through trial and error. Therefore, it is necessary to provide the operator with 3D volumetric models of the object and object-related information as well such as locations, shape, size, material properties, and so on. Thus, in this paper, we propose a vision-based human interface system that provides an interactive, information-rich map through network-based information brokering. The system consists of an object recognition part, a 3D map building part, a networked knowledge base part, and a control part of the mobile robot.

• 한국철도학회논문집
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• 제4권3호
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• pp.102-109
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• 2001

In this paper, it has a proposal of the RFID reader antenna design that expand the dedicated short-range communication distance between a static object on the ground and a mobile object attached on the moving article. The static reader equipped with micro-processor makes it possible to have a serial communication with a main system, so that much data can be transfer to the main system. An antenna is adjusted in order to a communication, the scale is designed by results values of simulation using matlab. It is achieved to systematically manage logistics, person resource and security system by grasping the information and location of mobile object on the basis that this system receives the information between a static reader and a mobile object tag at 134.2kHz band on real time, also to make it possible the main system to process. Therefore, the reader antenna scale is controlled on the foundation of a magnetic field theory in order to expand a recognition distance of reader and tag, so that can be optimistically recognized with minimizing the direction influence of reader and tag.

• 전자통신동향분석
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• 제34권6호
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• pp.133-144
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• 2019

Although deep learning-based visual image recognition technology has evolved rapidly, most of the commonly used methods focus solely on recognition accuracy. However, the demand for low latency and low power consuming image recognition with an acceptable accuracy is rising for practical applications in edge devices. For example, most Internet of Things (IoT) devices have a low computing power requiring more pragmatic use of these technologies; in addition, drones or smartphones have limited battery capacity again requiring practical applications that take this into consideration. Furthermore, some people do not prefer that central servers process their private images, as is required by high performance serverbased recognition technologies. To address these demands, the object and scene recognition technologies for mobile/embedded devices that enable optimized neural networks to operate in mobile and embedded environments are gaining attention. In this report, we briefly summarize the recent trends and issues of object and scene recognition technologies for mobile and embedded devices.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2007년도 심포지엄 논문집 정보 및 제어부문
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• pp.339-340
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• 2007

This paper proposes a object avoidance algorithm that enables a mobile robot with laser scanner. Object detecting system has a function to detect object in front of the mobile robot by using a laser scanner. The proposed method based on probability distribution and finds local-paths to avoid collisions. Simulation results show the feasibility of the proposed method.