• Proceedings of the IEEK Conference
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• 2005.11a
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• pp.569-572
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• 2005

This paper proposed the design and implementation of a DSP platform for the various multimedia streaming. The DSP platform synchronizes with host PC to configure DSP and to transmit multimedia streaming through PCI. The suggested DSP platform decodes high-capacity video/audio data using the suggested high-speed FIFO, CPLD and memory interface. The buffer control techniques is proposed in other to avoid the under/over-run of the audio/video data during the audio/video decoding. For the DSP platform test, host PC transmits program stream(PS) that consists of the MPEG-2 video MP@ML and 5.1ch AC3 audio data (Coyote.mov file, half hour running time) to DSP platform. The DSP platform plays continuously back the high sound-quality audio and high-definition video at once.

• Journal of KIISE:Computer Systems and Theory
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• v.27 no.2
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• pp.160-168
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• 2000

In this paper, we present a performance monitor to trace and evaluate the performance of programs running on networked computers. The performance monitor of the JaNeC is online/batch as well as event/time driven. Since it is implemented with the Java programming language, it provides us with high portability among heterogeneous computer systems, and friendly graphical user interface. This performance monitor consists of various views such as 'Task/Event Filter' and 'TimeLine', 'Task View', 'Task Hoistory', 'Message Passing View', 'Host Cpu View', which allow the user to easily analyze event and time during the program execution.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1846-1847
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• 2006

In this study, we developed the real-time controller for control loading system (CLS) of aircraft simulator. The CLS is given the forces as inputs: the exerted force by a pilot, which is determined according to the position of the control stick, and the calculated force by the host computer. And then CLS makes the pilot feel the back loading force by supplying the motor drive with the actuator signal. The developed real-time controller for CLS is organized into the five parts which are the position sensing part including a encoder, the A/D converter part for the analog load cell signal, the communication interface part to communicate with the host, the D/A converter for the actuator signal, and the CPU DSP2812 to carry out a control algorithm. We constructed the test control loading system and carried out the experiment with the developed real-time controller. The experimental results showed that the real-time controller generates the back loading forces similar to the desired back loading force graph.

• Journal of the Korean Institute of Telematics and Electronics
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• v.25 no.10
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• pp.1252-1262
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• 1988

This paper describes a functional-level design and simulation of Graphics Processor(GP) which can be used in various graphics systems. GP is divided into two parts: One is CPU, and the other is the interface to I/O peripherals. In order to achieve fast execution of graphics instructions, the CPU has special ALU, barrel shifter and window comparator and a FIFO for instruction prefetch. I/O part controls the DRAM and VRAM which constitute the GP's local memory, generates the signals to drive monitor, and communicates with the host processor. The functional simulation of CPU was done on Daisy workstation while the I/O part was designed using GENESIL, a silicon compiler.

• Speech Sciences
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• v.15 no.2
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• pp.67-77
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• 2008

In this paper, we implemented a robust speech recognizer using the TMS320VC33 DSP. For this implementation, we had built speech and noise database suitable for the recognizer using spectral subtraction method for noise removal. The recognizer has an explicit structure in aspect that a speech signal is enhanced through spectral subtraction before endpoints detection and feature extraction. This helps make the operation of the recognizer clear and build HMM models which give minimum model-mismatch. Since the recognizer was developed for the purpose of controlling car facilities and voice dialing, it has two recognition engines, speaker independent one for controlling car facilities and speaker dependent one for voice dialing. We adopted a conventional DTW algorithm for the latter and a continuous HMM for the former. Though various off-line recognition test, we made a selection of optimal conditions of several recognition parameters for a resource-limited embedded recognizer, which led to HMM models of the three mixtures per state. The car noise added speech database is enhanced using spectral subtraction before HMM parameter estimation for reducing model-mismatch caused by nonlinear distortion from spectral subtraction. The hardware module developed includes a microcontroller for host interface which processes the protocol between the DSP and a host.

• Proceedings of the IEEK Conference
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• 2002.06e
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• pp.95-98
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• 2002

This paper presents a study on DSP(TMS320F240) controller design for multi-axes transportation system using BLDC servo motor. This BLDC servo motor controller was realized with DSP(Digital Signal Processor) and IPM (Intelligent Power Module). The multi-axes transportation system needs torque, speed, position control of servo motor for variable action. This paper implements those servo control with vector control and space vector modulation technique. As CPU of controller DSP(TMS320F240) is adopted because, it has PWM(Pulse Width Modulation) waveform generator, A/D(Analog to Digital) converter, SPI(Serial Peripheral Interface) port and input/output port etc. The controller of multi-axes transportation system consists of 3-level hierarchy structure that main host PC manages three sub DSP system which transfer downword command and are monitoring the states of end servo controllers. Each sub DSP system operates eight BLDC servo controllers which control BLDC servo motor using DSP and IPM Between host system and middle digital signal processor communicate with RS-422, between main processor and controller communicate with SPI port.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.5 no.3
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• pp.236-240
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• 2004

We have implemented image monitoring system on PXA255 processor based embedded board that is ported QT/Embedded 2.3.7 version. User is able to monitor camera's capture image for widely separated host PC at client PXA255 board target board by ethernet communication method. And we designed PCI interface card that control motor for camera's Pan & Tilt. Bitmap format's images of $320\times{240}$ size are displayed on PXA255 board's TFT-LCD and User is able to monitor wanted position's image by touch screen input method.

• Journal of the Institute of Convergence Signal Processing
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• v.5 no.1
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• pp.46-52
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• 2004

In this paper, we introduce a case study of developing a miniature humanoid robot which has 16 degrees of freedom, 42 cm heights, and 1.5kg weights. For easy implimentation, the integrated RC-servo motors are adopted as actuators and a digital camera is equipped on its head. So, it can transmit vision data to a remote host computer via wireless modem. The robot can perform staircase walking as well as straight walking and turning to any direction. The user-interface program running on the host computer contains a robot graphic simulator and a motion editor which are used to generate and verify the robot's walking motion. The experimental results show that the robot has various walking capability including straight walking, turning, and stairs walking.

• The KIPS Transactions:PartC
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• v.13C no.7 s.110
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• pp.813-820
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• 2006

The advance of computer and communication technologies enables the embedded systems to be equipped with the network communication interfaces. Their appearance in network leads to security issues on the embedded systems. An easy way to overcome the security problem is to adopt the packet filter that is implemented in the general computer systems. However, general packet filters designed for host computers are not suitable to embedded systems because of their complexity. In this paper, we propose a lightweight packet filter for embedded systems. The lightweight packet filter is implemented in the kernel code. And we have installed a Web-GUI interface for user to easily set the filtering policies at remote space. The experimental results show that the proposed packet filter decreases the packet delivery time compared to the packet filter designed for host computers and it is comparable to the systems without packet filter.

• The KIPS Transactions:PartB
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• v.9B no.5
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• pp.517-522
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• 2002

Mobile agent systems offer a new paradigm for distributed computation and a one of solution for limitation of existent Client-server model. Mobile agent systems provide interface that can migrate from host to host in a heterogenous network. For secure execution, it must solve security problem of mobile code before. In this paper, we are propose the protocol that applied signature technique and hash chain technique. This protocol enable one to offer forward integrity, non-repudiation, and forgery detection, when mobile agents are perform the task by migrating a network.