Yoon-Young Park

MONETA: an embedded monitoring system for ubiquitous network environments

Accurate and efficient monitoring of dynamically changing environments is one of the most important requirements for ubiquitous network environments. To exploit these ubiquitous environments, we designed and implemented a monitoring system called MONETA that can obtain sensor data transmitted from wireless sensors to hub nodes in embedded equipment. MONETA adopts Web technology for the implementation of a simple but efficient user interface that allows an operator to visualize any of the processes, elements, or related information in a convenient graphic form. We developed MONETA using a kernel wrapper mechanism. This wrapper is a software module that enables us to monitor the state information of several embedded devices without any modification to the kernel. This wrapping method has allowed us to increase the portability of the monitoring system to other platforms and reduce the time required to write monitoring software modules.

Fast mode decision algorithm for inter-frame coding in H.264 extended Scalable Video Coding

In Scalable Video Coding (SVC) standard, an exhaustive block mode search has been employed to determine the best coding mode for each macroblock (MB). This gives a high coding efficiency, however it causes very high computational complexity in encoding system. To reduce this complexity of the exhaustive mode search, we propose a fast mode determination algorithm for inter-frame coding based on correlative information between base layer and enhancement layers for providing coarse grain signal-to-noise ratio (CGS) scalability and spatial scalability. In the proposed algorithm, we use rate-distortion (RD) costs of BL_SKIP (base layer skip) and 16×16 modes, and mode information of a corresponding block of the base layer to finish inter-mode search procedure early in the neighboring enhancement layer. Also, an adaptive thresholding scheme is designed. We verify that the overall encoding time for all layers can be reduced up to 65% based on comparative analysis of experimental results with JSVM 9.12 reference software.

Simulation Analysis on BER Patterns Based Maritime Ad-hoc Networks

Shipbuilding is one of the major export industries of Korea, it has been occupied the top spot in world markets. It is not easy work to keep prestige up. It is necessary to develop the technologies of ship and IT convergence to strengthen competitive and to achieve sustainable growth. Wireless ad-hoc mesh network in sea environments is one of the important parts of ship and IT convergence. In this paper, the architecture of wireless maritime network communication is presented based on Wimax and the idea to simulate wireless communication on sea using Qualnet simulator is shown. We describe Bit Error Rate (BER) levels according to sea status, affects physical layer of wireless communication. BER patterns are designed using MATLAB.

A Study on the Design of the Monitoring Architecture for Embedded Kernels based on LTT

Embedded systems are used in many fields such as home appliances, terminals, controls, communications, etc. So, to manage, control, and test these embedded systems, monitoring programs have been developed variously. In this paper, to overcome the characteristic faults of embedded systems which have resource restrictions, we implemented a development environment based on NFS and designed a monitoring tool that can evaluate and analyze kernel performance in embedded equipment by using LTT(Linux Trace Toolkit). Also, we designed a method to show monitoring data collected by using a monitoring tool, called MONETA 2.0, through the web-page.

Monitoring Systems for Embedded Equipment in Ubiquitous Environments

Accurate and efficient monitoring of dynamically changing environments is one of the most important requirements for ubiquitous network environments. Ubiquitous computing provides intelligent environments which are aware of spatial conditions and can provide timely and useful information to users or devices. Also, the growth of embedded systems and wireless communication technology has made it possible for sensor network environments to develop on a large scale and at low-cost. In this paper, we present the design and implementation of a monitoring system that collects, analyzes, and controls the status information of each sensor, following sensor data extracted from each sensor node. The monitoring system adopts Web technology for the implementation of a simple but efficient user interface that allows an operator to visualize any of the processes, elements, or related information in a convenient graphic form.

Distributed algorithms solving the updating problems

In this paper, we consider the updating problems to reconstruct the biconnected-components and to reconstruct the weighted shortest path in response to the topology change of the network. We propose two distributed algorithms. The first algorithm solves the updating problem that reconstructs the biconnected-components after the several processors and links are added and deleted. Its bit complexity is O((n′ +a +d) logn′), its message complexity is O(n′ +a +d), the ideal time complexity isO(n′), and the space complexity isO(e logn +e′ logn′). The second algorithm solves the updating problem that reconstructs the weighted shortest path. Its message complexity and ideal-time complexity areO(u2 +a +n′) respectively.

A Study on the Design of Fault-Tolerant Sensor Routing Algorithm for Monitoring of Ship Environmental Information

The goal of this research is to enhance the maintenance and monitoring system of ship environment using sensor network. It is important to know the location information of sensor nodes to control the sensors and to obtain the sensor data from sensor network inside the ship. In this paper, we address the grouping and routing mechanism according to the relative distance of sensor nodes, based on LEACH and PEGASIS. We also consider the fault tolerant mechanism using the location information of sensor nodes.

Striping and scheduling for large scale multimedia servers

When designing a multimedia server, several things must be decided: which scheduling scheme to adopt, how to allocate multimedia objects on storage devices, and the round length with which the streams will be serviced. Several problems in the designing of large-scale multimedia servers are addressed, with the following contributions: (1) a striping scheme is proposed that minimizes the number of seeks and hence maximizes the performance; (2) a simple and efficient mechanism is presented to find the optimal striping unit size as well as the optimal round length, which exploits both the characteristics of VBR streams and the situation of resources in the system; and (3) the characteristics and resource requirements of several scheduling schemes are investigated in order to obtain a clear indication as to which scheme shows the best performance in realtime multimedia servicing. Based on our analysis and experimental results, the CSCAN scheme outperforms the other schemes. It is believed that the results are of value in the design of effective large-scale multimedia servers.

ART : An Implementation on the Active_object RunTime Systems Applicable for the Embedded Systems

Active object is an Independent runnable unit which is scheduled by CPU in creation time. In this paper, we define the active object and suggest ART(Active object RunTime support systems) which controls creation and execution of the active object. ART can Provide users locational transparency and support easy method call mechanism. We also designed a communication model among active objects and implemented a communication method to make the distributed programing possible. The implementation target platform of ART is an embedded system which has only limited resources and runs in the distributed computing environment.