Jongryool Kim

OF@TEIN: An OpenFlow-enabled SDN Testbed over International SmartX Rack Sites

In this paper, we will discuss our on-going effort for OF@TEIN SDN (Software-Defined Networking) testbed, which currently spans over Korea and five South-East Asian (SEA) collaborators with internationally deployed OpenFlowenabled SmartX Racks.

Multi-View Video and Multi-Channel Audio Broadcasting System

In recent years, various multimedia services have become available and the demand for realistic multimedia systems is growing rapidly. The multi-view video and multi-channel audio are expected to satisfy the user demand for realistic multimedia services. In this paper, we present a new broadcasting system incorporating multi-view video and multi-channel audio over IPTV and MPEG-21 DIA. The proposed system includes data acquisition, camera calibration, data encoding and decoding, transmission, intermediate view reconstruction, and multi-view display and multi-channel audio play. In this paper, we discuss the main features of multi-view video and multi-channel audio.

Real-time synchronous multi-view video transport system over IP networks

This paper proposes a prototype realization of real-time synchronous multi-view video transport system which can extend the software-based multi-view video transport system over IP networks. This system supports H.264/MPEG-2 system based real-time multi-view video transport and considers the synchronization during acquisition and transport for the interactive view-selection during transport. For the synchronized acquisition from multiple multi-view cameras through IEEE 1394 interface, this system estimates the timeline differences among H.264 compressed video streams by using global time of network between the cameras and a server and corrects timelines of video streams by changing the timestamp of the MPEG-2 system stream. Then, it multiplexes a selected number of acquired views at the MPEG-2 TS (transport stream) level for the interactive view-selection during transport. Thus, with the proposed synchronized multiplexing scheme, this system can display synchronized view.

Multi-View 3D Video Transport using Application Layer Multicast with View Switching Delay Constraints

This paper proposes an efficient method to deliver multi-view 3D video in a synchronous manner for nodes that frequently switch views by employing application layer multicast (ALM) trees. The proposed method attempts to bound inter-view delay variation by managing ALM trees with delay and delay variation constraints. The resulting view-switching between selected nodes of different ALM trees can thus provide synchronized view of multi-view videos and improve the immersive experience of end users.

A synchronized multiplexing scheme for multi-view HD video over IP system

This paper proposes a prototype realization of multi-view HD video transport system with synchronized multiplexing over IP networks. The proposed synchronized multiplexing considers the synchronization during video acquisition and the multiplexing for the interactive view-selection during transport. For the synchronized acquisition from multiple HDV camcoders through IEEE 1394 interface, we estimate the timeline differences among MPEG-2 compressed video streams by using global time of network between the cameras and a server and correct timelines of video streams by changing the timestamp of the MPEG-2 system stream. Also, we multiplex a selected number of acquired HD views at the MPEG-2 TS (transport stream) level for the interactive view-selection during transport. Thus, with the proposed synchronized multiplexing scheme, we can display synchronized HD view.

Multiple magnetic transitions and magnon gaplike characteristics in the high purity TbB4 single crystal

We synthesized the high purity TbB4 single crystal, which shows quite low resistivity at T=2K, ρ(T=2K)=0.0397μΩcm, resulting in a high residual resistivity ratio RRR≡ρ(300K)∕ρ(2K)=361.9. Because of the geometry of the grown single crystals, temperature-dependent magnetization M(T) was measured with applied magnetic field parallel to (010) and (111) planes. M(T) was found to be anisotropic at high temperature and revealed two magnetic transitions: one is antiferromagnetic transition at TN=44K and the other one at Tm≈23K for both field orientations. These transitions were also manifested by the slope change of temperature-dependent resistivity, i.e., dρ(T)∕dT. The second transition temperature Tm was found to decrease and the transition width broadened with increasing applied magnetic field, indicating that the transition at Tm is suppressed by applied magnetic field. The Fermi liquid and antiferromagnetic (AF) magnon gaplike increase of ρ(T) was found at low temperatures of T⩽20K. The AF magnon gap Δ=15.6K...

Low dimensional intermediate valence fluctuation in single crystalline YbB4

Temperature-dependent magnetization M(T), resistivity ρ(T), and specific heat Cp(T) were measured for single crystalline YbB4. M(T) showed a large anisotropy, that is M‖(T)>M⊥(T), for fields parallel and perpendicular, respectively, to the c axis. While M‖(T) followed Curie-Weiss behavior with slight crystalline electric field splittings, M⊥(T) showed a typical temperature dependence of intermediate valence (IV) fluctuation, which implies that YbB4 is a rare compound with two-dimensional IV fluctuation. ρ(T) followed ρ0+AT2 below Tcoh≈5K, indicating a low-temperature Fermi liquid state of YbB4. In addition, anomalies were also found at ≈Tcoh in M(T), ρ(T), and Cp(T).

Challenges and Realization of Real-Time Multi-view Video Transport Systems over IP Networks

This paper describes about challenges in realizing realtime multi-view video transport systems over IP networks, obtained through our experience in prototyping two kinds of software-based multi-view video transport systems. First, targeting a 3D-version of interactive IPTV service, a realtime view-switchable multi-view 3D video transport system is implemented and evaluated. Second, a real-time panoramic multi-view video transport system is prototyped to demonstrate presence-style service for interactive collaboration environments. By discussing the realization of prototype systems, we attempt to discuss diverse challenges related to synchronized capturing and play-out of multiview video, view-switching and network-adaptive transport of multiplexed multi-view streams.

Reducing transmission latency of real-time resilient video distribution by employing cumulative random linear coding

In this work-in-progress paper, we present a network coding scheme based on random linear coding (RLC), named cumulative RLC. Cumulative RLC applies RLC in a cumulative manner such that the end-to-end delay is minimized and it can be used for real-time one-to-many video distribution over wireless networks. The proposed cumulative RLC is well-suited especially for media applications with low-latency constraints such as real-time resilient video distribution for interactive service scenarios. The key property of cumulative RLC is reducing the waiting delay during the RLC encoding procedure. To verify the efficiency of the proposed cumulative RLC, we implement a real-time resilient video distribution system employing cumulative RLC over a IEEE 802.11-based wireless network. Experimental results show that in a typical setting, cumulative RLC yields reducing RLC encoding delay so it can help efficient real-time video distribution.

Simulating Reliable Real-Time Data Distribution for UAV-aided Tactical Networks

CPS (cyber-physical system) is a kind of system that exhibits a tight combination of system computation and physical elements. This tight integration of computing and physical elements is achievable depending on the performance of reliable data communication among CPS nodes. To support the domain-specific quality requirements of reliable real-time CPS networking, we should deploy a network-adaptive reliable data distribution scheme while paying extra attention to the incurring computational complexity of selected error control modules. In this paper, by taking the example of reliable real-time data distribution for UAV(unmanned aviation vehicle)-aided tactical networks, we discuss how to build a simulation environment that can evaluate the tradeoff of CPS networking performance and resource consumption (in terms of computing and networking resources). To validate the appropriateness of constructed simulation environment, we apply specific error control building blocks on the resource-constrained multi-level hierarchical UAV-aided tactical WiMax networks and evaluate their performance and resource consumption.