• Proceedings of the Korea Information Processing Society Conference
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• 2017.04a
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• pp.553-555
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• 2017

수전 설비 시스템은 전력 회사에서 3 상 전원을 받는 설비로, 전기를 공급받기 위한 설비이다. 정전이나 제품생산설비의 중단은 기업에 있어서는 경제적 손실이 매우 큰 사고일 수 밖에 없다. 요즘은 IoT 센서를 이용한 수전설비 관리 시스템의 활용이 늘어나고 있는 추세이다. IoT 센서를 이용한 수전 설비의 구축에서 정확한 상태 값의 센싱과 수집된 값의 전송, 그리고 정확성 판단에 대한 이슈들이 고려되어야 하며, 또한 기기간 통신을 통해 실시간 상호작용으로 수전설비의 고장을 어떻게 예방할 것인가에 대한 것이 중요하다. 본 연구에서는 수전 설비의 실시간 감지와 모니터링을 위한 목적으로 기존의 고장 및 오류 정보를 기반으로 하는 빅데이터 분석을 통해 발생 가능한 고장 및 오류를 사전 예측할 수 있도록 정보를 제공하는 것에 주안점을 두었다.

• Journal of Digital Contents Society
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• v.16 no.1
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• pp.123-126
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• 2015

This paper described fault tolerance system running on distributed multimedia. We implemented the error manager service so that the users participated in distribute multimedia collaborative work may refer synchronized error objects as the same view to others. distributed multimedia environment are based on IP-USN(Internet Protocol - Ubiquitous Sensor Network) and M2M(Machine to machine). This is a system that is suitable for detecting, sharing and recovering software error in distribute multimedia CSCW(Computer Supportes Cooperated Work) environment. With error synchronization system, a group cooperating users can synchronize error applications.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.16 no.5
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• pp.63-68
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• 2016

Audio mixer is an electronic device which performs a mixing of multiple audio signals. Digital mixer having various functions and scalability is spreaded thanks to advanced DSP and IT technology. However, digital mixer is more vulnerable to stability comparing to conventional analog mixer in the digital error or software error sense because its control is executed by SW. To solve this problem, in this paper, we propose a multi-channel digital analog hybrid mixer scheme, digital mixer error detection mechanism and malfunctioning switching technique. Also we develop the audio mixer having digital-analog hybrid structure. By simulation, we can sense the error of digital mixer except power loss in a 120ms, change into analog mixer mode automatically and provide continuous broadcasting function without mixer function loss.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.187.2-187.2
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• 2012

다목적실용위성 3호는 2012년 5월 발사되어, 위성 기능점검을 위한 시험을 성공적으로 완료하였다. 위성발사이후 태양전지판 전개를 포함하여 장착된 모든 전장품(Unit)을 순차적으로 모니터링하면서 관련 명령어를 송신하고, 이후 송신된 명령어에 대한 수행여부를 모니터링하며 전장품의 정상 동작상태를 판단하게 된다. 위성상태의 모니터링은 상태 디스플레이 페이지(AND, AlphaNumeric Display), 각종 이벤트 디스플레이 및 위성에서 수신한 덤프 데이터 디스플레이 등을 통해서 수행한다. 이러한 위성의 상태정보는 지상의 엔지니어가 신속하면서 정확한 판단을 수행할 수 있도록 정확한 정보를 가독성있게 디스플레이해야할 필요가 있다. 또한, 위성교신 이후에는 위성에서 저장된 상태정보를 수신하여 비실시간 위성상태 데이터를 분석하는 작업을 수행한다. 이때, 엔지니어가 필요로 하는 상태정보 아이템을 자신이 원하는 형태로 추출할 수 있어야 한다. 이러한 필수 기능들은 시스템의 안정성을 기반으로 동작하여야 한다. 이와 같은 시스템이 운영될 수 있도록 초기운영 이전에 안정화 및 검증 작업을 수행하였으며, 초기운영 기간에도 정상운영 단계에서 임무관제국의 운영요원이 용이하게 위성의 상태를 모니터링할 수 있도록 위성상태정보에 대한 데이터베이스와 오류 감지 능력을 포함하는 위성상태 표출 기능을 최적화 하는 작업을 수행하였다. 임무관제국에서 개발된 위성상태모니터링 시스템을 통하여 안정적으로 다목적실용위성 3호의 초기운영에 대한 실시간 모니터링 및 비실시간 데이터 분석 작업을 수행하였다. 또한, 초기운영기간동안의 최적화 작업을 통하여 정상운영기간 동안 운영요원이 용이하게 오류 감지를 수행할 수 있도록 시스템을 지속적으로 개선하였다.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.11 no.4
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• pp.95-103
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• 2012

In this paper, we implemented a surveillance system for the power transmission line protection from heavy-duty fender-bender. Laser scanning technology was applied for system design. It was analyzed detailed functions for designed system. Measured detection rate and error rate that are monitoring parameters for both studied system and conventional system were 100%, 0% and 95.8%, 2.1%, respectively. Measurement showed that studied system is almost perfect and better than conventional system. Because this system provides the information to frontline workers with managers of heavy equipments that have possibility of accident, it can be applied to surveillance system for the transmission line protection.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.47 no.8
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• pp.42-46
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• 2010

Energy detection based spectrum sensing compares the energy of a received signal from a primary user with a detection threshold and decides whether it is active or not in the frequency band of interest. Here the detection threshold depends on not only a target false alarm probability but also the level of the noise energy in the band. So, if the noise energy changes, the detection threshold must be adjusted accordingly to maintain the given false alarm probability. Most previous works on energy detection for spectrum sensing are based on the assumption that noise energy is known a priori. In this paper, we present a new energy detection scheme updating its detection threshold under the assumption that the noise is white, and analyze its detection performance. Analytic results show that the proposed scheme can maintain a target false alarm rate without regard to the noise energy level and its spectrum sensing performance gets better as the time bandwidth product of the signal used to estimate the noise energy increases.

• The Transactions of the Korea Information Processing Society
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• v.6 no.8
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• pp.2233-2244
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• 1999

It is essential to guarantee high reliability of embedded real-time systems since the failure of such systems may result in large financial damage or threaten human life. Though many researches have devoted to fault tolerant mechanisms, most of them are object-level fault tolerant mechanisms that can detect errors occurred in a single object and treat the errors in object-level. As embedded real-time systems become more complex and larger, there exist faults that cannot be detected by or tolerated with object-level fault tolerance. Hence, system-level fault tolerance is needed. System-level fault tolerance examines the status of a system whether the system is normal or not by analyzing the status of objects. When an error is detected it should be capable of locating the fault and performing an appropriate recovery and reconfiguration action. In this paper, we propose RobustRTO(Robust Real-Time Object) that provides object-level fault tolerance capability and RMO(Region Monitor real-time Object) that offers system-level fault tolerance capability. Then we show how highly dependable fault tolerant systems can be modeled by RobustRTO and RMO. The model is presented based on real-time objects.

• The Transactions of the Korea Information Processing Society
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• v.3 no.5
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• pp.1059-1069
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• 1996

The purpose of this paper is to examine some effects of four menu types: icon menu, context menu, pulldown menu, and bar selection menu. In order to find whether there are some effects of menu types or learning stages (the first, intermediate and the last stage) on skill-based errors, each of the menus has been studied in relation to hyperemia instruction, menu search time, scholastic a chievements and learners' metacognitionon their errors. A further purpose of this paper is to suggest some strategies for enabling learner to select menus more efficiently in order to enhance the learner's own learning effectiveness in hypere mia instruction.The results of this study are as follows. The menu types had a significant effect on the low metacognition regulation group. The context menu types had a significant effect on achievements. In contrast, it was also noticed he the menu types did not have any significant effect on the high metacognition regulation group. The bar-selection menu type and the icon menu type had a relatively significant effect on skill-based errors in the first stage of learning.

• Journal of Advanced Navigation Technology
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• v.12 no.6
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• pp.666-672
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• 2008

This paper explains late comer and error recovery process for home network environment with session management. This system consists of an ED, ES, and ER. ED is an agent that detects an error by hooking techniques for multimedia distance education based on home network environment with session management. ES is an agent that is an error sharing system for multimedia distance education based on home network environment with session management. ER is a system that is suitable for recovering software error for multimedia distance education based on home network environment with session management. This paper explains a performance analysis of an error recovery system running on distributed multimedia environment using the rule-based DEVS modeling and simulation techniques. The proposed method is more efficient than the other method in comparison with error ration and processing time.

• Progress in Medical Physics
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• v.26 no.2
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• pp.112-117
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• 2015

In order to establish the quality control on patient safety following the guideline presented by American Association of Physicists in Medicine (AAPM) TG-100 committee, we aim to analyze the modes based on errors occurred during treatment of patients at the radiation oncology department at Yeungnam University Hospital and establish a quality control guideline for patient safety when patient-centered radiation treatment is conducted. We aim to analyze the errors that can occur during radiation treatment at the radiation department, and assess the frequency of error, the severity of error affecting patients, and probability of proceeding without noticing error, with scores. The places where errors can take place were divided into CT simulation treatment room, treatment planning room, and treatment room for the analysis. In CT simulation treatment room, an error from using the immobilization device showed the highest Risk Priority Number (RPN) value of 60, and an error from simulation treatment information input showed the lowest of 6. In treatment planning room, an error from selecting the radiation dose calculation model showed the highest RPN value of 168, and an error of patient treatment start date showed the lowest of 36. In treatment room, a Table Bar error showed the highest RPN value of 252, a weight change error showed 190, and a Pillow error showed the lowest of 24.