Seung-Chul Son

A Blind Calibration Scheme Exploiting Mutual Calibration Relationships for a Dense Mobile Sensor Network

In sensor-based measurement systems, the sensor calibrations are crucial to obtain the correct measured values. In this paper, we propose a new blind calibration scheme for a massive mobile sensor network. The mutual calibration relationships between colocated sensors are utilized in a densely deployed sensor network. We model the calibration relationships in a linear algebraic model, and derive an equivalent Laplacian matrix. By just solving the Laplacian linear equation, we can determine how much each sensor has to be calibrated. The proposed calibration scheme is explained as a generalized extension of the simple mean model scheme to the mobile sensor network. Theoretical analysis and simulation results show that the proposed linear algebraic model improves the accuracy of the simple mean model by nearly σdrift2/σnoise2 times at maximum, in terms of mean square error, where usually σdrift ≫ σnoise. In addition, we show the feasibility of our scheme on human movements, by applying the scheme to the Levy-walk model in the simulation. The most important advantages of our scheme are that the calibration model is straightforward and that the solution is simply obtained with a matrix inversion.

Fast required bandwidth estimation technique for network adaptive streaming

Research into high quality media streaming is regarded as an important area of information technology with the rapid development of network technology and digital A/V home appliances. However, a scheme that can flexibly deal with extreme network dynamics is required to realize high quality media streaming service because the modern internet is designed for best effort services. In this paper, we design and implement a scheme that controls quality of service (QoS) based on whether the network can accommodate the required bandwidth of the media. The relative one-way delay (ROWD) trend is used to determine whether the required bandwidth is available and the temporal coding of scalable video coding (SVC), which can be easily applied to real-time systems, is introduced to control QoS. Experimental results conducted with a fiber-to-the-home (FTTH) network show that the proposed system appropriately adapted to variations in network bandwidth and the service quality improved.

Scenario-based 3D Objects Synthesizing System Design

This paper proposes the framework of the scenario-based 3D image synthesizing system that allows common users who envision a scenario in their mind to realize it into the segments of cool animation. We focused on utilization of the existing motions to synthesize new motions for the objects. The framework is useful to build a 3D animation in game programming with a limited set of 3D objects. We also propose a practical algorithm to reuse and expand the objects. This algorithm is based on motion path modification rules. Both linear and nonlinear curve-fitting algorithms were applied to modify an animation by key frame interpolation and to make the motion appear realistic.

Implementation of embedded Linux platform based vehicle feature extractor for ITS

This paper propose the vision based vehicle feature extractor which can be operated on the low performance embedded linux platform. In addition, we implement an intelligent transportation system applying the OGC SWE framework for integrating with conventional analog CCTV based traffic surveillance system. The proposed method is comprised of the moving vehicle detection, license plate recognition and vehicle color detection stage. The fast operation is possible by limiting the feature extraction area in the each step. The experimental result feature extractor can be effectually integrated with the conventional system. It provides the exact vehicle identification information.

Context-awareness Based SVC Multimedia Broadcast Service

As recent integration of wire and wireless networks and the convergence of telecommunications and broadcasting, uniform and standardized by the broadcasting operators of existing stations to provide 4A(Any-time, Any-where, Any-device, Any-contents) services for the next-generation of multimedia services research is being progressed. Demand for theses next-generation multimedia services to ensure video compression coding technology, as well as mobility, ability to operation a variety of devices, characteristics and performance of user network and the status and conditiion, user preferences and context-awareness based on the technology has an interest in technical studies. In this paper, the current internet environment, SVC(Scalable Video Coding) encoded by a mixture of multicast and overlay multicast transmission technology for broadcasting services by designing and efficient multimedia broadcasting system is proposed. In addition, ACK-Aow Optimization by overlay multicast scheme existing tree-based overlay multicast, and by comparing the effectiveness of the proposed algorithm is demonstrated.