Yunmo Chung

A serial connection technique of speakers for multi-channel audio systems

This paper proposes a serial transmission technique of signals for multi-channel audio systems. The technique converts analog audio signals of multiple channels of an audio unit into digital signals, and transfers the digital signals to the speakers through a serial line sequentially. Each speaker is allowed to select its corresponding digital audio signals and to transform the signals into analog audio signals to make sounds for the speaker. The functions of the proposed technique are modeled in VHDL, implemented with FPGA chips, and tested for actual audio systems.

Integrated system of face recognition and sound localization for a smart door phone

This paper proposes a smart system using both face recognition and sound localization techniques to identify foreign faces through a door phone in a more efficient and accurate way. In particular, a visitors voice is used to localize the proper location of the speaker. The location information is then used to adjust the door phone camera position to frame the face in its field of view. In order to accurately locate the facial position of the visitor, 4 microphones are positioned in a cross configuration. Furthermore, face detection and face recognition algorithms as well as a wireless interface are used to recognize the visitor and send the information to the home owners phone. The entire control system is built using an FPGA chip and tested for actual use in door phone environments1.

Reducing the Overhead of Real-Time Operating System through Reconfigurable Hardware

This paper demonstrates the benefits of hardwiring two of the main RTOS functionalities for multitasking environment. They are context switching and software interrupt processing operations. In particular, the paper proposes reconfiguring the FPGA which includes the proposed one time reconfigurable CPU and RTOS hardware, optimized for a given application by tailoring the entire hardware around the particular tasks involved. As a demonstration, the proposed RTOS hardware was designed and tested on a multichannel speaker system application to yield 60% performance increase over the conventional software- based RTOS.

A hardware framework for smart speaker control of home audio network

Multi-channel speaker systems are typically driven by central power amplifiers. This approach has limitations when faced with the increasing number of channels in existing systems. In this paper, more distributed approach to multi-channel systems is proposed where a USB cable is used as an interface to a living room PC to connect to the proposed main controller. The main controller connects all speaker channels serially via a network cable through subcontrollers that are distributed across the rooms. The network cable interface between the sub-controllers and the main controller uses a custom-made transmission protocol. This protocol allows the main controller to provide multiple CD quality audio sources to different locations in a house. Furthermore we demonstrate a bidirectional communication capability to allow seamless personalized listening at all locations in the home with the proposed protocol between the main controller and the sub-controllers.

Robust Tracking of Ultrasonic Pen for Handwriting Digitizer Applications

The paper introduces a two step noise reduction method to improve the tracking of the pen movements through ultrasonic signaling. The results indicate substantial improvements compared to a direct read out method. Furthermore, the two step method can be augmented by a time slot hopping method to avoid signal interference between two similar devices tracking the respective pen movements in close proximity.

Web-based CAD framework for low cost SoC design prototyping

In this paper, we propose a framework that allows an efficient way of designing and verifying an SoC. In particular, the proposed SoC design framework, which is based on the OpenRISC platform, utilizes the web environment to reduce the tooling costs while providing similar design times for a small work group. Expensive processing tasks, such as RTL level simulations and cross-compilations, are performed on the remote central server. The server also allows a user to share his or her IP libraries with different clients with user controllable library access permissions. The client is a 15MB program that performs and interfaces to all other tasks required for the SoC design. We demonstrate that the proposed server-client interface performs almost seamlessly.

Integration of face recognition and sound localization for a smart door phone system

This paper proposes a smart system using both face recognition and sound localization techniques to identify the faces of visitors from a door phone in much efficient and accurate ways. This system is effectively used to recognize the faces when their locations are out of the boundaries of the camera scope of the door phone. The smart door phone system proposed in this paper uses a visitors voice source to rotate the camera to his face and then to recognize the face accurately. The integrated system has been designed with one FPGA(Field Programmable Gate Array) chip and tested for actual use in door phone environments.

Intergrated control system of multi-channel audio signals for serial transmission

In this paper, we propose a system which can easily control the existing serially connected multi-channel speakers using a USB(universal serial bus) interface. The host computer chooses a sound source and sends audio data in a real-time fashion using isochronous transmission, which is one of four transmission methods provided by the USB interface. In addition, a channel is assigned to use the bulk transmission method. Transmitted data from the USB host are compressed and packetized before being sent serially to the speakers. Each speaker detects corresponding digital data and regenerates audio signals through DAC(digital-to-analog converter). A user can easily select a sound source file and a channel by the use of a GUI environment in the host computer.

Commercial Advance Technology with a DVDR System

The paper implements a technique of skipping commercials that can be implemented on media such as DVDRs (digital versatile disc recorders) or HDD (hard disc drive) recorders. This approach makes seamless replay of regular programming uninterrupted by commercials possible. Relatively old and complex tape recording scheme of current VCRs (video cassette recorders) is quickly being replaced with the advanced digital recording schemes on optical discs. The commercial skipping scheme implemented in this paper is applicable to all kinds of PVR (personal video recorder) devices that record broadcasting signals for delayed playback.

Efficient ROM correction technique for digital home appliances

The problem of emergence of fatal bugs in the software that drives microprocessors embedded in digital home appliances necessitates a rescrutiny of strategies that are used to revamp software functionalities of such systems. Existing strategies to remedy such problems involve disintegrating the entire system in order to replace the execution of a defective program of the ROM that stores the software. This paper proposes an efficient and a facile technique that corrects the functions of the ROM using a remote controller based on wireless message transmission and reception. The main advantage of this technique is that unlike existing techniques it does not need entire system disintegration to fix the ROM running the software program. In addition, we extend the proposed technique to be applied for a digital convergence appliance embedding two microprocessors by means of a CD-R instead of the remote controller.