• Journal of Institute of Control, Robotics and Systems
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• v.13 no.12
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• pp.1198-1206
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• 2007

It is common to use PC or Digital picture frame in stand-alone fashion to view images, movies, or to listen MP3 musics which are considered as multimedia contents, However, such existing methods have weakness for expanding network requirements or augmenting extra data, in such case inevitably requiring external devices. With keeping in mind for such expansion, in this study, we have suggested a new concepts of network module which may utilize an image server for data transmission, in the proposed module, data alarm packet was defined for alerting incoming data from the image server and it became possible to synchronize between the image server and device not only in wired but also in wireless environments through UART. The method consists of a control module for an image server and a synchronization module between the server and the device. We have also tested the feasibility for future commercial usages such as advertisements through performance evaluations.

• IEMEK Journal of Embedded Systems and Applications
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• v.6 no.6
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• pp.369-376
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• 2011

Since wireless sensor networks generally have the capability of network recovery, malfunction of a few sensor nodes in a sensor network does not cause a crucial problem paralyzing the sensor network. The malfunction of the sink node, however, is critical. If the sink node of a sensor network stops working, the data collected by sensor nodes cannot be delivered to the gateway because no other sensor nodes can take the place of the sink node. This paper proposes a TDMA-based wireless sensor network equipped with dual sink nodes, with a view to preventing data loss in the case of malfunction of a sink node. A secondary sink node, which synchronizes with a primary sink node and receives data from other sensor nodes in normal situations, takes the role of the primary sink node in the case of malfunction of the primary sink, thereby eliminating the possibility of data loss. The effectiveness of the proposed scheme is demonstrated through experiments.

• IEMEK Journal of Embedded Systems and Applications
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• v.14 no.5
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• pp.249-258
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• 2019

In the cyber-physical system, big data collected from numerous sensors and IoT devices is transferred to the Cloud for processing and analysis. When transferring data to the Cloud, merging data into one single file is more efficient than using the data in the form of split files. However, current merging and splitting operations are performed at the user-level and require many I / O requests to memory and storage devices, which is very inefficient and time-consuming. To solve this problem, this paper proposes kernel-level partitioning and combining operations. At the kernel level, splitting and merging files can be done with very little overhead by modifying the file system metadata. We have designed the proposed algorithm in detail and implemented it in the Linux Ext4 file system. In our experiments with the real Cloud storage system, our technique has achieved a transfer time of up to only 17% compared to the case of transferring split files. It also confirmed that the time required can be reduced by up to 0.5% compared to the existing user-level method.

• KEPCO Journal on Electric Power and Energy
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• v.6 no.4
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• pp.405-411
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• 2020

In this paper, we designed the COS MEMS system for sensing the falling detection and explosive noise of fuse link in COS (Cut Out Switch) installing on the power distribution. This system analyzed the failure characteristics and an instantaneous breakdown of power distribution. Therefore, our system strengths the industrial competence and guaranties the stable power supply. In this paper, we applied BLE (Bluetooth Low Energy) technology which is suitable protocol for low data rate, low power consumption and low-cost sensor applications. We experimented with LSM6DSOX which is system-in-module featuring 3 axis digital accelerometer and gyroscope boosting in high-performance mode and enabling always-on low-power features for an optimal motion for the COS fuse holder. Also, we used the MP34DT05-A for gathering an ultra-compact, low power, omnidirectional, digital MEMS microphone built with a capacitive sensing element and an IC interface. The proposed COS MEMS system is developed based on nRF52 SoC (System on Chip), and contained a 3-axis digital accelerometer, a digital microphone, and a SD card. In this paper of experiment steps, we analyzed the performance of COS MEMS system with gathering the accelerometer raw data and the PDM (Pulse Data Modulation) data of MEMS microphone for broadcasting the failure of COS status.

• Magazine of the Korea Concrete Institute
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• v.24 no.3
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• pp.20-24
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• 2012

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.44 no.12
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• pp.102-107
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• 2007

This paper proposes a H.264/AVC entropy decoder without embedded processor nor memory fabrication process. Many researches on H.264/AVC entropy decoders require ROM or RAM fabrication process, which is difficult to be implemented in general digital logic fabrication process. Furthermore, many researches require embedded processors for bitstream manipulation, which increases area and power consumption. This papers proposes hardwired H.264/AVC entropy decoder without embedded processor, which improves data processing speed and reduces power consumption. Furthermore, its CAVLC decoder optimizes lookup table and internal buffer without embedded memory, which reduces hardware size and can be implemented in general digital logic fabrication process without ROM or RAM fabrication process. Designed entropy decoder was embedded in H.264/AVC video decoder, and it was verified to operate correctly in the system. Synthesized in TSMC 90nm fabrication process, its maximum operation frequency is 125MHz. It supports QCIF, CIF, and QVGA image format. Under slight modification of nC register and other blocks, it also support VGA image format.

• Journal of the Institute of Electronics Engineers of Korea SD
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• v.46 no.8
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• pp.41-52
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• 2009

In Motion JPEG2000 encoding, huge bandwidth requirement of data memory access is the bottleneck in required system performance. For the alleviation of this bandwidth requirement, a new embedded compression(EC) algorithm with a little bit of image quality drop is devised. For both random accessibility and low latency, very simple and efficient entropy coding algorithm is proposed. We achieved significant memory bandwidth reductions (about 53${\sim}$81%) and reduced code-block memory to about half size through proposed multi-mode algorithms, without requiring any modification in JPEG2000 standard algorithm.

• KIPS Transactions on Software and Data Engineering
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• v.4 no.9
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• pp.419-424
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• 2015

As Internet of Things (IoT) is recently serviced in several fields, the reliability and safety issues for IoT embedded systems are emerged. During the development of embedded systems, it is not easy to build the virtual execution environment and to test the developing version. Therefore, it is difficult to ensure its reliability due to lack of unit testing. In this paper, we propose a log-based unit testing framework for embedded software, which performs on real target board by extracting information of function execution. And, according to execution paths, duplicated logs are eliminated to keep a minimal log size. As a result, during system testing, testers can efficiently decide whether the executed paths of each function are correctly performed or not.

• The KIPS Transactions:PartA
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• v.14A no.5
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• pp.295-300
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• 2007

The Linux-based embedded systems such as mobile telephones. PDAs and MP3 players are widely in use. USB(Universal Serial Bus) is the interface for data communication between the computers and these peripheral devices. Some embedded systems like intelligent home networking and multimedia streaming require guaranteed QoS(Quality of Service), which is needed for real time transmission of UDP/IP messages through USB. Although USB Ethernet driver is supported by USB Gadget API in Linux, it is unable to provide the desirable QoS required by each type or small embedded systems due to the unpredictability or TCP/IP Stack in Linux. This paper proposes IP-Over-USB to improve QoS of UDP/IP message transmission in the embedded systems using USB in Linux system.

• Journal of the Korea Society for Simulation
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• v.25 no.1
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• pp.35-43
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• 2016

Increasing the proportion of an embedded system in automotive industry, test methods for evaluation and fault detection of the embedded system have been researched. HILS is a test method that is used in the development and test of complex real-time embedded systems. In this study, we defined the HILS method of the ECU, one of the embedded systems used in automobiles. Our method is to create a test model that can provide a virtual vehicle environment to the ECU on the basis of the actual vehicle data. The test model has reference information that can transmit the sensor signal and CAN Message into the ECU from HILS tester. In this study, the HILS can detect faults of the target ECU.