• Journal of Korean Society for Geospatial Information Science
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• v.20 no.3
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• pp.49-56
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• 2012

Performance analysis on RAIM, which is one of the techniques for monitoring integrity to ensure the reliability of GPS, was conducted in this study. RAIM is such a method which allows its user to monitor integrity in the stand-alone mode. Among the existing RAIM procedures, the representative methods including the RCM (Range Comparison Method), LSRM (Least Square Residual Method), Parity approach and WRAIM (Weighted RAIM) were evaluated, and their performance was analyzed. To validate the performance of the implemented algorithms, fault detection was tried on the clock malfunctioning event of PRN 23 occurred on January 1st, 2004. As a result, it was identified that the LSRM and the WRAIM detected all the faults happened in the event. In the case of RCM, all the states of fault were detected except for the error which occurred as a false alarm at one epoch. Furthermore, simulated biases were added for each satellite to analyze the sensitivity of each algorithm. Consequently, when biases of the 9-13 meters range were simulated for the RCM and LSRM algorithm, all the malfunctions were detected. For the WRAIM method, it could detect range biases greater than 15 meters.

• Journal of the Korean Institute of Gas
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• v.24 no.2
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• pp.36-43
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• 2020

Gas system fire extinguishing equipment is a very economically useful facility, but if it is not used for a long period of time after installing the equipment, there is possibility of rupture due to corrosion of containers and operation errors of equipment systems, and this is very dangerous. However, it is impossible to experiment to check whether the equipment is operating normally. If gas is temporarily released into the enclosed space due to rupture and malfunction, it can cause serious human damage due to gas suffocation. In this study, based on the suffocation death accident of gas system fire extinguishing facility, the inflow path of released gas and the possibility of death and time to death were estimated using a 3D scan and FLACS.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2017.05a
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• pp.613-614
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• 2017

Recently, research on the automation of home IoT has been carried out in which IoT (Internet of Things) is applied inside the home. However, the conventional IoT automation system has a problem that the operation of the device is limited only by the threshold value of the sensor, so that the device may collide and interfere with each other and the efficiency of the Task is low due to the malfunction of the device. In this paper, we propose a Situation-specific task classification algorithm to solve these problems. Using the sensor threshold and the current date as classification values in the decision tree, the task according to the internal situation of the home is classified and the corresponding device is selected and proceeded. Therefore, it is expected that the users will be provided with a service that changes flexibly according to changes in the internal situation of the home, and the accuracy of the operation will be increased by reducing the malfunction of the device and the collision between the devices.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.28 no.2
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• pp.155-158
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• 2017

With the help of technical development in the electronic industries, the electronic devices employing the cutting-edged technology are spread in all the area requiring electromagnetic communications. Especially, because of the presence of electronic devices in a variety of research fields like automotive vehicle, train, and aircraft, the research area such as the malfunction and critical damage of the internal system and microwave devices due to the unexpected radiated high-powered EM effects are very important even for the possible occurrence of human damage. In this paper, the effects of electromagnetic fields into the cable connecting the electronic devices and many sensors inside the target structure is treated because of potential malfunction or hardware disorders. In addition, correlation function and transmission line theory have been employed for the analysis of the induced current on the cable inside an electrically large resonant structure.

• The Journal of The Korea Institute of Intelligent Transport Systems
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• v.20 no.2
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• pp.79-94
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• 2021

A GNSS receiver installed in autonomous vehicles is the most essential device for its navigation. However, if an intentional jamming signal is generated, there is a risk of exposure to an accident risk due to deterioration of the GNSS sensor's performance. Research is required to prevent this, and accordingly, a jamming generating device must be provided. However, according to the provisions of the law related to jamming, this is illegal. In this paper, we implement an in-vehicle jamming device that complies with the provisions of the law and does not affect the surrounding GNSS sensors. Driving simulation is used to evaluate the performance of the GNSS algorithm, and the malfunction of autonomous vehicles occurring in the interference environment and data errors output from the GNSS sensor are analyzed.

• Journal of the Korean Institute of Gas
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• v.22 no.6
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• pp.28-33
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• 2018

Currently, the government has been expanding the supply of semi-low-pressure in order to solve the problems of unsupplied area of city gas and to secure the economical efficiency of small supplied area. It is mainly supplied from the central storage tank to each household by buried piping. It is necessary to provide such a shutoff valve that can block the excess flow gas due to pipeline leak or rupture when piping is damaged by other construction. For this study, System CFD code named Flownex has been used and a component corresponding to the actual EFV was developed. We compared Flownex results with experimental data to verify the accuracy of Flownex and confirmed the error rate to be around 2%. In this study, pipeline network modeling was done by selecting the LPG supply pipeline in a village and installed the component of the EFV at each junction. We selected the longest pipeline from the main pipeline and set scenarios so that the excess flow occurs by that the pipeline is ruptured before entering the household. The excess flow occurs by the pipeline rupture and the EFV is closed. At this time, we analyzed backflow effects to the other pipeline by closing EFV.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.19 no.2
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• pp.169-174
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• 2019

This paper propose a system to notify the user that detects failure of malfunction of smart farm ICT devices. As the fourth industrial revolution approaches, agriculture is also fused with ICT technology to improve competitiveness. Smart farming market is rapidly growing every year, but there is still a lack of standardization and certification systems. Especially, smart farm devices that are widely used in Korea are different in product specifications, software and hardware are developed separately, and quality and compatibility are poor. Therefore, a system that can recognize the abnormality of the equipment due to the frequent damage of farmers using low cost smart farm equipment is needed. In this paper, we review smart farm domestic and overseas policy trends and domestic smart agriculture trends, analyze smart farm failure or malfunctions and proactively prevent them, and propose a system to inform users when problems occur.

• Journal of the Institute of Convergence Signal Processing
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• v.22 no.1
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• pp.1-6
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• 2021

Recently, unmanned facilities have been introduced and operated in a way that reduces the cost and development of IT technology. Although unmanned facilities have advantages in terms of efficiency and economy, they have disadvantages such as failure of unmanned facilities and malfunctions, causing damage to facilities caused by intruders, and information leakage. In addition, it is necessary to visit the person in charge at all times to inspect the unmanned facilities, resulting in management costs. In this paper, we designed a system that checks the status of unmanned surveillance facilities in real time to check and automatically recover problems such as malfunctions, and to notify managers of situations by text messages in real time. The system to be designed consists of an integrated network video server (NVR) that receives and determines information on the operation status of the main equipment such as video, sound, and lighting, and a real-time text message using an SMS server.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.279-286
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• 2012

Recently, design of Universal Soft Controller(USC) has been applied to the advanced control room for nuclear power plant. USC is software-based manual control means to control safety components as well as non-safety components in the highly-integrated control room. Therefore, design feature of USC is essential for the implementation of a single workstation in the advanced control room. The traditional control room is replaced by computer-driven consolidated operator interfaces. Considering our design has further reduced the probability of USC spurious signals by requiring two distinct operator control actions to generate any control signal. The reality of USC does not increase the probability of reactor trip because the probability of spurious USC signal is negligible. Universal Soft Control represents a significant evolution in nuclear I&C/HSI System. USC integrates the indicators and controls from multiple divisions into a single integrated visual display unit(VDU) based HSI(Human System Interface). In order to prevent adverse influence on safety function performance from USC failure, ESFAS signals are applied to safety components or functions. In addition, safety manual switches have priority over USC's signals. Therefore, spurious USC signals can be momentarily blocked by selecting a soft control command from the safety VDU.

• Proceedings of the Korea Information Processing Society Conference
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• 2013.11a
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• pp.831-834
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• 2013

최근 퍼징(Fuzzing, Fuzz Testing)이 소프트웨어의 취약점을 찾아내기 위한 방법으로 활발하게 사용되고 있다. 퍼징은 반복적으로 비정상적인 데이터를 무작위로 생성하여 대상 소프트웨어에 입력 값으로 전달해 오작동을 유도하고, 오작동의 원인을 분석하여 소프트웨어의 취약성을 찾아낸다. 퍼징에서 사용되는 입력 값인 테스트 케이스에 따라서 취약점 탐지율 및 탐지 시간이 결정된다. 따라서 어떻게, 어떤 테스트 케이스를 생성하여 퍼징을 실행 할 것인지가 퍼징 연구의 핵심이다. 퍼징을 위해 생성하는 테스트 케이스는 숫자가 굉장히 많기 때문에 최근에 테스트 케이스의 크기를 축약하여 퍼징 결과 분석을 위해 소요되는 시간을 줄이는 연구가 발하게 진행되고 있다. 본 논문에서는 테스트 케이스 축약에 이용되는 다양한 알고리즘들에 대해 소개하고, 그 각각을 비교 분석하여 향후 퍼징의 테스트 케이스 축약에 관한 연구에 기여하고자 한다.