Il-Gu Jung

Smart scanning for mobile devices in WLANs

A recent proliferation of mobile devices led to immense deployment of WLAN access points (APs). IEEE 802.11 mobile devices periodically perform active background scanning to discover available APs in the vicinity. However, this periodic active scanning imposes unnecessary overhead in a static WLAN environment. This paper addresses this scanning overhead issue of mobile devices in IEEE 802.11 WLANs and proposes a smart scanning method using a motion sensor. Our scheme scans channels only if the signal strength from the associated AP becomes below a specified threshold and a mobile device is moving. The smart scanning suppresses unnecessary periodic background scans. We implemented the smart scanning in a commercial smartphone and evaluated its performance in a real indoor WLAN environment. The experimental and simulation results show that the smart scanning can significantly reduce the scanning overhead, the number of unnecessary handoffs and force disconnections.

Power Efficient Clustering for Wireless Multimedia Sensor Network

The availability of inexpensive hardware such as CMOS cameras and microphones has fostered the development of wireless multimedia sensor networks (WMSNs). In WMSNs, wirelessly interconnected devices enable ubiquitously retrieving multimedia contents such as video and audio streams, and still images along with scalar data from surroundings for wide range of applications are constrained by processing, memory, and power resources. Image compression via low-complexity and resource efficient transforms has been addressed by several researchers to prolong network lifetime where energy conservation is achieved through sharing computational load among sensor nodes and by adjusting the transmission ranges of camera nodes. However, those schemes are not adaptive to the presence and changes of energy level of computational sensor nodes and to the amount of computational load. We propose a resource and energy efficient distributed image compression algorithm that dynamically configures according to the energy levels and the forwarding strategy that is based on the entropy of the image. The simulation results show that our adaptive distributed image compression scheme significantly prolongs the network lifetime and improves the network utilization efficiency, while maintaining adequate image quality.

Detecting a large number of objects in real-time using apache storm

Object detection is an important function for intelligent multimedia processing, but its computational complexity prevented its pervasive uses in consumer electronics. To process large-scale datasets in real-time, more resources and reliable infrastructures are required for spreading the data and running the applications across multiple machines in parallel. In order to detect a large number of objects in real-time, a task-parallel processing framework based on Storm is proposed.

An efficient mobility management scheme for convergence mobile media multicast services in NGN

This paper proposes mobility management architecture and scheme for network-based convergence mobile media multicast service, called Access Independent Mobile Service - with Mobile Multicast (AIMS-MM), which provides fast and seamless multicast service handover mechanism among heterogeneous wireless access networks with the minimum modifications on terminal devices. The proposed scheme applies a method to fast re-join the relevant multicast stream by enabling the AIMS-MM system to collect multicast group information through multicast group information handler located in the multicast router and providing related information to the router upon terminal handover. The advantage of the proposed method can provide an efficient seamless multicast service with fast connecting when they handover each other among heterogeneous wireless access networks with the proposed mobility management scheme. Also, the proposed scheme can provides the reliability and resource efficiency in the wireless area via exclusion of signaling in the wireless area. Through numerical analysis and the test-bed implementation, we have shown the superiority and practicality of the proposed scheme convergence mobile media multicast services in NGN. Experimental results show that the proposed method with AIMS-MM improve QoS with reducing delay time when comparing with MIP-BT-opt, HMIP-BT-opt, PMIP, etc., methods in terms of multicast service handover and etc.

Web-based transmission and playback system for multi-camera video

We present a novel web-based transmission and playback system for multi-camera video. The proposed system transmits a user-selected camera view video by DASH-based scheme. A transmitted video is streamed and played on the web-based video player. In the experimental test, user is able to get a selected camera viewpoint video about five times faster than conventional DASH scheme.

The development of object based video contents management technology for broadcasting service

In recent years, Many people want to watch their interesting object from their wanted viewing angle when they watch sports or soap opera on TV. Thus, we have developed object based video contents management system for the personalized broadcasting service.

System for Proving N-screen Service Using Depth-Based Visual Object Groupings

This paper is the thing about the system development which it groups the independent visual objects with the group value unit and extracts each grouping objects with the interesting object unit and can interaction with the user in the various screen devices.

System and Its Method for Reusing an Application

In the open USN(Ubiquitous Sensor Network) service platform, USN application only requests to the open USN service platform and remaining processing is done by the open USN service platform. But, the Open USN service platform which being developing as the international standards needs to consider an open interface for a service request of different service providers. Therefore, the Open USN service platform for heterogeneous applications by combining existing applications require interfaces that can be reused. We designed the system which could infer and recombine the application which it can reuse from the pre-registered applications. Thus, we can reuse pre-registered applications so that can reduce the cost and effort for implementing a duplicated application. Besides, there can be an advantage which has the function of one source multi use.

A Network-Based Mobile Multicast Framework for Heterogeneous IP-Based Networks

We suggest a new mobile multicast scheme which does not uses any tunnels for multicast traffic and can be provides the reliability and resource efficiency in the wireless area via exclusion of signaling in the wireless area. The scheme is based on AIMS which is not very well-known, but it is mobility management architecture like MIP and PMIP. And we analyze the performance of the proposed scheme compared with MIP and PMIP. Through this numerical analysis, we weighed up the pros and cons of various mobile multicast methods.

Design of hybrid multi-view camera system using IR-coated mirror

We present a novel hybrid multi-view video camera system using IR-coated mirror. Proposed system consists of three high-resolution color video cameras and one time-of-flight (TOF) depth camera. In the proposed system, IR-coated mirror is installed between the color camera and the TOF depth camera at the center. With this mirror, we are able to minimize the field-of-view (FOV) and the image center position differences between two cameras. Test sequences captured by the proposed camera system show the effectiveness of the proposed camera system.