Hyung-Min Yoon

Application of a wavelet adaptive filter to minimise distortion of the ST-segment.

A wavelet adaptive filter (WAF) for the removal of baseline wandering in ECG signals is described. The WAF consists of two parts. The first part is a wavelet transform that decomposes the ECG signal into seven frequency bands using Vaidyanathan-Hoang wavelets. The second part is an adaptive filter that uses the signal of the seventh lowest-frequency band among the wavelet transformed signals as primary input and a constant as reference input. To evaluate the performance of the WAF, two baseline wandering elimination filters are used, a commercial standard filter with a cutoff frequency of 0.5 Hz and a general adaptive filter. The MIT/BIH database and the European ST-T database are used for the evaluation. The WAF performs better in the average power of eliminated noise than the standard filter and adaptive filter. Furthermore, it shows a lower ST-segment distortion than the standard filter and the adaptive filter.

Reconfigurable Address Collector and Flying Cache Simulator

Trace-driven simulation is widely used to evaluate the cache memory system. The accuracy of the trace-driven simulation depends on the accuracy and length of the trace data. To achieve an accurate and long trace, trace collection hardware is designed. The flying cache simulator is attached to the tracing system to simulate various cache systems during the execution of an application program. The tracing system designed, called the Reconfigurable Address Collector and Flying Cache Simulator (RACFCS), can generate accurate and long traces and simulate the cache system for a long execution time.

Implementation of new services to support ubiquitous computing for campus life

The various services that make up the ubiquitous computing concept have developed with the rapid growth of wireless Internet environments and mobile devices. The major purpose of this research is to provide a context-aware U-Town environment to users by utilizing sensors and mobile devices currently available in the public sector and the marketplace. In this paper, the first step of the UTOPIA (Ubiquitous computing TOwn Project: Intelligent context Awareness) project is to introduce the U-Campus service (Ubiquitous computing for the campus). The paper introduces services such as the U-Restaurant, U-Museum, and the U-Theme Park, which are the second step of the U-Town project. In addition, we introduce the MoCE (Mobile Context Explorer) architecture, which is the context-aware recognition technology used to realize U-Town project services.

Real-time Ray-tracing Chip Architecture

In this paper, we describe the world’s first real-time ray-tracing chip architecture. Raytracing technology generates high-quality 3D graphics images better than current rasterization technology by providing four essential light effects: shadow, reflection, refraction and transmission. The real-time ray-tracing chip named RayChip includes a real-time ray-tracing graphics processing unit and an accelerating tree-building unit. An ARM Ltd. central processing unit (CPU) and other peripherals are also included to support all processes of 3D graphics applications. Using the accelerating tree-building unit named RayTree to minimize the CPU load, the chip uses a low-end CPU and decreases both silicon area and power consumption. The evaluation results with RayChip show appropriate performance to support real-time ray tracing in high-definition (HD) resolution, while the rendered images are scaled to full HD resolution. The chip also integrates the Linux operating system and the familiar OpenGL for Embedded Systems application programming interface for easy application development.