• Proceedings of the Korean Institute of Intelligent Systems Conference
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• 2008.04a
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• pp.259-263
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• 2008

The dynamics of mobile robot is nonlinear. To cope with this nonlinearity, many advanced control schemes have been proposed recently. Generally, the advanced control schemes are complicated and not good for the practical real-time control when they are implemented as control programs. So, in this paper, a relatively simple PI controller is proposed and applied to the position control of mobile robot with the adoption of reference trajectory calculation method used for the AUV(Autonomous Underwater Vehicle) control. The proposed PI controller is programmed using LabVIEW which is popular for its graphical programming characteristics. The simulation and experimental results show the feasibility and effectiveness of the proposed PI controller.

• Journal of Communications and Networks
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• v.4 no.4
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• pp.336-343
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• 2002

A major challenge for next generation mobile communication is capturing the system architecture’s complexity with all its internal and external dependencies. Seamless integration of heterogeneous environments in all system parts is a key requirement. Moreover, future systems have to consider the different evolution cycles of individual system parts. Among those, services are expected to change the fastest. With respect to these considerations, we propose an overall architecture for next generation mobile communication systems. It covers all system parts from wireless transmission to applications including network and middleware platform. Our approach focuses on adaptability in terms of recon- figurability and programmability to support unanticipated system evolution. Therefore, we consider abstraction layers which consist of adaptable cooperating components grouped by open platforms rather than rigid system layers. In addition to that, we introduce cross-layer cooperation allowing an efficient use of the available resources. Specific scenarios illustrate the feasibility of our approach.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.1099-1104
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• 2003

In this paper, the position control of a car-like mobile robot using neural network is proposed. The positional information of the mobile robot is given by a laser range finder located remotely through wireless communication. The heading angle is measured by a gyro sensor. Considering these two sensor information as references, the robot posture by localization is corrected by a cascaded controller. In order to improve the tracking performance, a neural network with a cascaded controller is used to compensate for any uncertainty in the robot. The remotely located neural network filter modifies the reference trajectories to minimize the positional errors by wireless communication. A car-like mobile robot is built as a test-bed and experimental studies of proposed several control algorithms are performed. It turns out that the best position control can be achieved by a cascaded controller with neural network.

• Journal of Advanced Navigation Technology
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• v.15 no.4
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• pp.562-570
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• 2011

In this paper, a distributed mobile relay power control (DMRPC) scheme for maximizing individual cell throughput is proposed for mobile relay aided multi-cell orthogonal frequency division multiplexing (OFDM)-time division duplex (TDD) system. In the system with DMRPC, the power levels of relay's are controlled by individual cell without cell cooperation and signalling overhead. It is demonstrated by numerical simulation that DMRPC provides the better cell throughput performance than either the full power relay aided system or conventional system without relay does. Moreover, it is also shown that relay aided systems with DMRPC, and the conventional system have almost identical cell edge throughput, while full power relay aided systems show worse performance in cell edge throughput.

• Proceedings of the IEEK Conference
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• 2008.06a
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• pp.335-336
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• 2008

By using DM(Diagnostic Monitoring) data measured at WiBro network, automatic optimization function of WiBro network is implemented in this paper. The optimization function mentioned is able to be run on PC with 2GHz CPU and 1 GB memory. Automatic optimization function is one module of CellTREK that is a wireless network planning and optimization software developed by Infra Lab., KT.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.441-441
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• 2000

In wheeled mobile robot (WMR) research, point stabilization is one of the basic research issue. Point stabilization is to set mobile robot in desired position regardless of its orientation. In this paper, we propose a point stabilization scheme for car-like type WMR. We will define a new error states named as tangential error and nomal error. Then a heuristic control scheme will be suggested. The performance of these approach is verified via POSTUR-II.

• 제어로봇시스템학회:학술대회논문집
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• 1997.10a
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• pp.819-824
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• 1997

This paper presents a cell-based motion control strategy for soccer playing mobile robots. In the central robot motion planner, the planar ground is divided into rectangular cells with variable sizes and motion indices to which direction the mobile robot should move. At every time the multiple objects-the goal gate, ball, and robots-detected, integer values of motion indices are assigned to the cells occupied by mobile robots. Once the indices being calculated, the most desirable state-action pair is chosen from the state and action sets to achieve successful soccer game strategy. The proposed strategy is computationally simple enough to be used for fast robotic soccer system.

• ETRI Journal
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• v.30 no.3
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• pp.432-440
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• 2008

In this paper, a user-friendly mobile photo album system and albuming functions to support it are introduced. Stand-alone implementation in a mobile device is considered. The main idea of user-friendly photo browsing for albuming functions is to enable users to organize and browse their photos along semantically meaningful axes of events, personal identities, and categories. Experimental results demonstrate that the proposed method would be sufficiently useful and efficient for browsing personal photos in mobile environment.

• Proceedings of the Korea Inteligent Information System Society Conference
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• 2001.01a
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• pp.83-88
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• 2001

To get the items that a buyer wants in Internet auction. he must search for the items through several auction sites. When the bidding starts, he(the buyer) needs to connect to these auction sites frequently so that he can monitor the bid stats and re-bid. A reserve-price auction reduces the number of connections, but this limits the user's bidding strategy. Another problem is equity between the buyer and the seller. Both the buyer and the seller should profit together within proper limits. In this paper, we propose an auction agent system using a collaborative mobile agent and a brokering mechanism called MoCAAS (Mobile Collaborative Auction Agent System), which mediates between the buyer and the seller and executes bidding asynchronously and autonomously. This reduces connection costs. offers more intelligent bidding and solves the equity problem.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2005.05a
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• pp.945-948
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• 2005

Mobile computing devices are becoming increasingly prevalent in a huge range of physical area, offering a considerable market opportunity. The focus of this paper is on the development of a platform of fault diagnosis system integrating with personal digital assistant (PDA). An improvement of induction machine rotor fault diagnosis based on AI algorithms approach is presented. This network system consists of two parts; condition monitoring and fault diagnosis by using Artificial Intelligence algorithm. LabVIEW allows easy interaction between acquisition instrumentation and operators. Also it can easily integrate AI algorithm. This paper presents a development environment fur intelligent application for PDA. The introduced configuration is a LabVIEW application in PDA module toolkit which is LabVIEW software.