Sang-Hyun Bae

IoT as a applications: cloud-based building management systems for the internet of things

Recently, excellent by Internet of Things (IoT), the era of connected everything device is coming. However, the devices hardly show the manner to autonomous connectivity on it and the self-cooperation for applied to real-world environments. In this paper, we proposed a smart building on IoT and cloud-based technology that can perform collaboration and efficient operation with various sensing devices in building and facilities. The smart building is very important to reduce on a huge amount of building energy is consumed by the management system of buildings. The proposed system selects an optimum device feature subset from the computing resources and storages by our cloud-based building management system. The performance of our proposed system is tested via experiments which verify that its measures are satisfactory.

Similarity Retrieval Based on SOM-Based R*-Tree

Feature-based similarity retrieval has become an important research issue in multimedia database systems. The features of multimedia data are usually high-dimensional data. The performance of conventional multidimensional data structures tends to deteriorate as the number of dimensions of feature vectors increases. In this paper, we propose a SOM-based R*-tree(SBR-Tree) as a new indexing method for high-dimensional feature vectors. The SBR-Ttree combines SOM and R*-tree to achieve search performance more scalable to high dimensionalities. When we build an R*-tree, we use codebook vectors of topological feature map which eliminates the empty nodes that cause unnecessary disk access and degrade retrieval performance. We experimentally compare the retrieval time cost of a SBR – Tree with that of an SOM and an R*-tree using color feature vectors extracted from 40,000 images. The result show that the SOM-based R*-tree outperforms both the SOM and R*-tree due to the reduction of the number of nodes required to build R*-tree and retrieval time cost.

A design of presentation system for interactive multimedia contents based on event-driven processing model

In this paper, we propose a system for multimedia presentation with users participation based on events to play-out multimedia contents consisting of various heterogeneous media objects through a network. We define various types of events and propose methods for handling them with Event Constructor, Event Scheduler and Event Queue Manager. In addition, Network Manager and QoS Manager are proposed to manage network delays and to maintain the required QoS of an interactive multimedia presentation. With the proposed presentation system, a user can make a multimedia content with users participation based on a user-defined scenario, and give a synchronous presentation through a presentation manager handling the events with priority. Finally, we implement it in Windows XP environment using Visual C++ 6.0 programming platform, and show an example of multimedia content and its presentation.

Traffic control scheme of VCNs' gigabit ethernet using BP

VCNs (Virtual-Connection Networks) of gigabit-ethernet can be efficiently used to transport packet data services. The switching system will sup-port voice and packet data services simultaneously from end to end applications. To guarantee quality of service (QoS) of the offered services, source rate to send packet data is needed to control the network overload condition. Most existing control algorithms are shown to provide the threshold-based feedback control technique. However, real-time voice calls can be dynamically connected and released during data services in the network. If the feedback control information delays, quality of the serviced voice can be degraded due to a time delay between source and destination in the high speed link. An adaptive algorithm based on the optimal least mean square error technique is presented for the predictive feedback control technique. The algorithm attempts to predict a future buffer size from weight factor (slope) adaptation of unknown functions, which are used for feedback control. Simulation results are presented, which show the effectiveness of the algorithm.

Traffic Control Scheme of ABR Service Using NLMS in ATM Network

ATM ABR service controls network traffic using feedback information on the network congestion situation in order to guarantee the demanded service qualities and the available cell rates. In this paper we apply the control method using queue length prediction to the formation of feedback information for more efficient ABR traffic control. If backward node receive the longer delayed feedback information on the impending congestion, the switch can be already congested from the uncontrolled arriving traffic and the fluctuation of queue length can be inefficiently high in the continuing time intervals.