• BMB Reports
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• v.52 no.11
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• pp.653-658
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• 2019

MYB-type transcription factors (TFs) play important roles in plant growth and development, and in the rapid responses to unfavorable environmental conditions. We recently reported the isolation and characterization of a rice (Oryza sativa) MYB TF, OsMYB102, which is involved in the regulation of leaf senescence by downregulating abscisic acid (ABA) biosynthesis and the downstream signaling response. Based on the similarities of their sequences and expression patterns, OsMYB102 appears to be a homolog of the Arabidopsis thaliana AtMYB44 TF. Since AtMYB44 is a key regulator of leaf senescence and abiotic stress responses, it is important to examine whether AtMYB44 homologs in other plants also act similarly. Here, we generated transgenic Arabidopsis plants expressing OsMYB102 (OsMYB102-OX). The OsMYB102-OX plants showed a delayed senescence phenotype during dark incubation and were more susceptible to salt and drought stresses, considerably similar to Arabidopsis plants overexpressing AtMYB44. Real-time quantitative PCR (RT-qPCR) revealed that, in addition to known senescence-associated genes, genes encoding the ABA catabolic enzymes AtCYP707A3 and AtCYP707A4 were also significantly upregulated in OsMYB102-OX, leading to a significant decrease in ABA accumulation. Furthermore, protoplast transient expression and chromatin immunoprecipitation assays revealed that OsMYB102 directly activated AtCYP707A3 expression. Based on our findings, it is probable that the regulatory functions of AtMYB44 homologs in plants are highly conserved and they have vital roles in leaf senescence and the abiotic stress responses.

• Proceedings of the Korean Society of Computer Information Conference
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• 2017.01a
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• pp.3-4
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• 2017

본 논문에서는 가상화 기술을 지원하는 ARMv7 Cortex-A15 프로세서가 탑재된 임베디드 보드를 위한 실시간 운영체제(RTOS) 구현을 위한 방법을 제안한다. ARM Cortex-A15 프로세서가 지원하는 Generic Interrupt Controller와 Generic Timer에 대해 알아보고, 가상화 시스템에서 인터럽트 오버헤드를 줄이는 GICv2와 가상 타이머인 Generic Timer를 사용하여 실시간 운영체제인 FreeRTOS를 임베디드 보드에 이식하였다.

• Proceedings of the Korean Information Science Society Conference
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• 2005.07a
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• pp.832-834
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• 2005

임베디드 시스템은 범용 컴퓨팅 시스템과 달리 자신을 포함하고 있는 기기에 부과된 특정 목적의 컴퓨팅 작업만을 수행한다. 이 시스템을 제어하기 위해서 운영체제가 필요로 하며, 임베디드 환경에서는 신뢰성과 정확성을 요하는 부분이 많기 때문에 실시간 운영체제를 필요로 한다. Real-Time kernel을 기반으로 하는 MicroC/OS-II는 수많은 용도로 사용되고 있지만 task 사용에 한계가 있다. 이 논문에서 제안하는 스케줄링은 task의 생성 수를 늘려주지만, 이 경우 task간의 우선순위 설정이 어려워진다. 이 문제 해결을 위해서 task들의 우선순위 결정은 deadline을 이용하여 3레벨로 나눈다. 3레벨로 나누어지면 task의 수가 증가해도 개발자는 task들을 레벨에 맞게 설정하면 task 관리로 인하여 생기는 문제를 줄일 수 있으며, 효율적인 스케줄링을 가능하게 한다.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10b
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• pp.1032-1035
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• 1996

While Ethernet and TCP/IP are the most widely used protocol, for Real-time system, it is not applicable because it doesn't guarantee the deterministic transmission time. Furthermore, the TCP acknowledgement scheme and sliding window algorithm enforce to collide packets. Although various Collision-Free CSMA protocol was presented, it is very difficult to implement in well known OS(UNIX, WilidowsNT) because we have to modify network kernel. This paper presents another transmission protocol based on modified UDP. The colliding probability can be minimized by avoiding successive packet transmission and decreasing competition duration. The proposed algorithm can be used for the soft real-time industrial automation network.

• Journal of the Korea Society of Computer and Information
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• v.21 no.6
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• pp.1-7
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• 2016

An uninterruptible power supply (UPS) allows small companies and domestic users to cope with power outages; but existing designs lack flexibility of control and require expensive battery maintenance, with a cost proportional to the outage compensation time. We combine a compact synchronous generator with a battery, with 10% of the capacity that would otherwise be required, to obtain a UPS with reduced maintenance costs for the same performance. Any UPS must respond immediately to a power loss, and our uninterruptible generator supply (UGS) is therefore built around real-time scheduling of its internal operations; this also makes it suitable for integration into the industrial gateway. The UGS is based on a real-time operating system, with an integrated wireless module providing connectivity to a web server, for monitoring and management, which can be performed remotely on a mobile device.

• Journal of Institute of Control, Robotics and Systems
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• v.13 no.11
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• pp.1074-1081
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• 2007

This paper presents a method for real-time face detection and tracking which combined Adaboost and Camshift algorithm. Adaboost algorithm is a method which selects an important feature called weak classifier among many possible image features by tuning weight of each feature from learning candidates. Even though excellent performance extracting the object, computing time of the algorithm is very high with window size of multi-scale to search image region. So direct application of the method is not easy for real-time tasks such as multi-task OS, robot, and mobile environment. But CAMshift method is an improvement of Mean-shift algorithm for the video streaming environment and track the interesting object at high speed based on hue value of the target region. The detection efficiency of the method is not good for environment of dynamic illumination. We propose a combined method of Adaboost and CAMshift to improve the computing speed with good face detection performance. The method was proved for real image sequences including single and more faces.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2005.11a
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• pp.117-120
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• 2005

A Digital Broadcasting Satellite (DBS) receiver converts digital A/V streams received from a satellite to analog NTSC A,/V signals in real-time. Multi-tasking is an efficient way to improve the utilization of the processor core in real-time applications. In this paper, we propose a hybrid approach with a balanced trade-off between hardware kernel and multi-tasking programming to increase a system throughput. First, the schedulability of the critical hard real-time tass in the DBS receiver is verified by using a simple feasibility test. Then. several soft real-time tasks are thoughtfully programmed to satisfy functional requirements of the system.

• Proceedings of the KIEE Conference
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• 2006.10c
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• pp.151-153
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• 2006

When distributed powers are interconnected to the grid, lack of source stability may cause some events that should be measured and stored as soon as they occur. This paper presents a real-time hardware system that has been developed for quick and reliable monitoring of the distributed powers quality. The system is composed of a digital signal processor (MPC7410, Motorola) and a 16 bits A/D board (VMIVME3122, GE). To guarantee the real time operation, it is based on a real time OS (VxWorks). Hardware tests of the embedded system have been made to check the performances of the proposed system. Test signals of several events are generated by using a LabView (hardware) system. The tests show that the system complies with the desired IEEE standard for power quality monitoring.

• Proceedings of the Korea Information Processing Society Conference
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• 2007.05a
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• pp.1195-1198
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• 2007

In this paper we study the problem of real time support in wireless sensor networks and propose a Real time Geographic Routing Protocol (ReGeo) which routes a packet towards the destination based on a compromise between distance and queue count to reduce traffic concentration wherever it has been determined to be too high and uses Gradient Table to store the route satisfying the delay constraints. We describe our prototype implementation of ReGeo Routing in TOSSIM - a TinyOS mote simulator. The simulation results show that the proposed routing protocol not only increases the packet delivery ratio but also keeps overall End to End Delay under a bounded value.

• Proceedings of the KSR Conference
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• 2009.05a
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• pp.1473-1479
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• 2009

Recently, the high speed train was operated and then the train system's reliability requirements are growing more and more. The exact prediction simulation is necessary in the design of power feeding system by the increase of railway electrification. In order to develope the AC feeding system analysis technology, real-time power simulator was manufactured. It is composed to eight channels analog input, forty channels analog output and forty-eight channels digital I/O. The size of simulator rack is 19" and the two I/O boards are installed the PXI chassis built into the real time os. The signal I/O is possible through BNC connector. The test results of manufactured simulator are obtained that the error range of analog I/O signal is below 1 % and simulation condition is set to 1 ms and the simulation output of the analog output compares the results of the simulator.