• Journal of Korea Multimedia Society
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• v.10 no.8
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• pp.958-966
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• 2007

In this paper, we implement a sound-enhanced MPEG-1 audio decoder on embedded OS Platform. Low bit rate lossy audio codecs such as MP3, OGG, and AAC for mitigating the problems in storage space and network bandwidth suffer a major common problem such as a loss of high frequency fidelity of audio signal. This high frequency loss will reproduce only a band-limited low-frequency part of audio in the standard CD-quality audio. In order to overcome this problem, we embedded a sound enhancement algorithm into the MPEG-1 audio decoder and then the algorithms optimized according to the characteristic of the MPEG-1 audio layer I, II, III were implemented on an embedded OS platform. From the experimental results with spectrum analysis and listening test, we confirm the superiority of the proposed system compared to the standard MPEG-1 audio decoder.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.31 no.10B
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• pp.883-890
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• 2006

The study of sensor network database is beginning to liven up as we are interested in Ubiquitous Computing technology in hardware, communication, database and so on. Especially, as new smart sensors have capabilities of real-time information gathering and analysis of each sensor node, data processing becomes an important issue in Ubiquitous Computing. In thesis, we have applied TinyDB(query processing system) to carry sensor node with line tracer which can follow the fixed path. After we gathered data around path, we have processed data in TinyDB GUI, gathered data, displayed data on a web server. Also we have a web browser on an embedded board for convenient user interface and implemented touch screen such that users can operate with a finger.

• Journal of Convergence for Information Technology
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• v.9 no.7
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• pp.25-32
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• 2019

This paper proposes the method of an in-vehicle gateway to reduce the reprogramming time for the ECU (Electronic Control Unit). In order to reduce the reprogramming time, the gateway must prohibit transmitting messages, that are not related to reprogramming, to the destination CAN network, and no ECU should diagnose the DTC(Diagnostic Trouble Code) that indicates CAN communication error caused by prohibiting CAN messages by the gateway. Moreover, STmin, which are the minimum time between two consecutive CAN messages, should be minimized. In order to do this, this paper proposes the method that uses the link control command specified in UDS(Unified Diagnostic Services) and hardware based gateway functionality that are supported by the latest MCU(Micro Controller Unit). The proposed method is developed using TC275 based embedded system, and its results are presented.

• Journal of IKEEE
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• v.18 no.3
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• pp.383-391
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• 2014

In this paper, temperature, pressure and flow analysis system for testing a fuel filter of a diesel engine at the low-temperature environment in winter, is proposed. The light oil of diesel engine below a specific temperature is changed to the waxing materials like paraffin, and it prevents engine to start easily because of reducing fluidity. Thus, built-in block heater should be installed with fuel filter in order to solve this problem. And it is necessary to design evaluation system that can analyze the performance according to temperature, pressure and flow characteristics near fuel filter at a very low temperature. In this paper, we measured a physical quantity related to the performance of around the fuel filter using the proposed system, and analyzed their characteristics. Also the measured data is transferred to remote user by using a web server of embedded systems, and analyzed their conditions in remote place via web browser in order to know the operating status of fuel filter. We installed the proposed system in a small test chamber to verify the performance and took an experiment in normal temperature and very low temperature, and could obtain temperature, pressure and flow of near the fuel filter. As a result, the fuel flow could be improved during operation of the fuel heater.

• Journal of the Korea Institute of Information Security & Cryptology
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• v.29 no.5
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• pp.1099-1116
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• 2019

Industrial control systems(ICS) are widely used in various industrial area and critical infrastructure. To mitigate security threats on ICS, the security assurance test for industrial control devices has been introduced and operating. The test includes testing of the security function of the device itself and testing of communication robustness. In this paper, we describe the security requirements of EDSA, Achilles, and Korea's TTA standard(security requirements for ICS). And also, we analyzed the characteristics of communication robustness test(CRT) of each certification. CRT verifies the device's operation of essential function while transmitting fuzzing and stress packets. Existing test methods are mostly focused on the embedded devices and are difficult to apply to various devices. We propose a method to test communication robustness which reflect the characteristics of control H/W, control S/W, field devices and network devices in ICS. In the future, we will apply the proposed communication robustness test to actual products and present solutions for arising issues.

• Journal of the Korea Society for Simulation
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• v.18 no.3
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• pp.73-82
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• 2009

Due to the many advantages including low price, low power consumption, and miniaturization, the CMOS camera has been utilized in many applications, including mobile phones, the automotive industry, medical sciences and sensoring, robotic controls, and research in the security field. In particular, the 360 degree omni-directional camera when utilized in multi-camera applications has displayed issues of software nature, interface communication management, delays, and a complicated image display control. Other issues include energy management problems, and miniaturization of a multi-camera in the hardware field. Traditional CMOS camera systems are comprised of an embedded system that consists of a high-performance MCU enabling a camera to send and receive images and a multi-layer system similar to an individual control system that consists of the camera's high performance Micro Controller Unit. We proposed the SL-AVS (Small Size/Low power Around-View System) to be able to control a camera while collecting image data using a high speed synchronization technique on the foundation of a single layer low performance MCU. It is an initial model of the omni-directional camera that takes images from a 360 view drawing from several CMOS camera utilizing a 110 degree view. We then connected a single MCU with four low-power CMOS cameras and implemented controls that include synchronization, controlling, and transmit/receive functions of individual camera compared with the traditional system. The synchronization of the respective cameras were controlled and then memorized by handling each interrupt through the MCU. We were able to improve the efficiency of data transmission that minimizes re-synchronization amongst a target, the CMOS camera, and the MCU. Further, depending on the choice of users, respective or groups of images divided into 4 domains were then provided with a target. We finally analyzed and compared the performance of the developed camera system including the synchronization and time of data transfer and image data loss, etc.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.40 no.1
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• pp.152-164
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• 2015

A rapid development of semiconductors, sensors and mobile network technologies has enable that the embedded device includes high sensitivity sensors, wireless communication modules and a video processing module for vehicular environment, and many researchers have been actively studying the smart car technology combined on the high performance embedded devices. The vehicle is increased as the development of society, and the risk of accidents is increasing gradually. Thus, the advanced driver assistance system providing the vehicular status and the surrounding environment of the vehicle to the driver using various sensor data is actively studied. In this paper, we design and implement the smart vehicular camera device providing the V2X communication and gathering environment information. And we studied the method to create the metadata from a received video data and sensor data using video analysis algorithm. In addition, we invent S-ROI, D-ROI methods that set a region of interest in a video frame to improve calculation performance. We performed the performance evaluation for two ROI methods. As the result, we confirmed the video processing speed that S-ROI is 3.0 times and D-ROI is 4.8 times better than a full frame analysis.