• Title/Summary/Keyword: Electrical Accidents

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Detecting Nighttime Pedestrians for PDS Using Camera in Visible Spectrum (가시 스펙트럼 대역 카메라를 사용하는 PDS를 위한 야간 보행자 검출)

  • Lee, Wang-Hee;Yoo, Hyeon-Joong;Kim, Hyoung-Suk;Jang, Young-Bum
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.10 no.9
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    • pp.2280-2289
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    • 2009
  • The death rate of pedestrians in car accidents in Korea is about 2.5 times higher than the average of OECD countries'. If a system that can detect pedestrians and send alarm to driver is built and reduces the rate, it is worth developing such a pedestrian detection system (PDS). Since the accident rate in which pedestrians are involved is higher at nighttime than in daytime, the adoption of nighttime PDS is being standardized by big auto companies. However, they are usually using expensive night visions or multiple sensors for their PDS. In this paper we propose a method for nighttime PDS using a monochrome visible spectrum camera. We could verify its superiority in both performance and real?time operation to existing algorithm through tests against video data taken in several different environments.

Electroencephalogram-based Driver Drowsiness Detection System Using AR Coefficients and SVM (AR계수와 SVM을 이용한 뇌파 기반 운전자의 졸음 감지 시스템)

  • Han, Hyungseob;Chong, Uipil
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.6
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    • pp.768-773
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    • 2012
  • One of the main reasons for serious road accidents is driving while drowsy. For this reason, drowsiness detection and warning system for drivers has recently become a very important issue. Monitoring physiological signals provides the possibility of detecting features of drowsiness and fatigue of drivers. One of the effective signals is to measure electroencephalogram (EEG) signals and electrooculogram (EOG) signals. The aim of this study is to extract drowsiness-related features from a set of EEG signals and to classify the features into three states: alertness, drowsiness, sleepiness. This paper proposes a drowsiness detection system using Linear Predictive Coding (LPC) coefficients and Support Vector Machine (SVM). Samples of EEG data from each predefined state were used to train the SVM program by using the proposed feature extraction algorithms. The trained SVM program was tested on unclassified EEG data and subsequently reviewed according to manual classification. The classification rate of the proposed system is over 96.5% for only very small number of samples (250ms, 64 samples). Therefore, it can be applied to real driving incident situation that can occur for a split second.

An Overview of Fault Diagnosis and Fault Tolerant Control Technologies for Industrial Systems (산업 시스템을 위한 고장 진단 및 고장 허용 제어 기술)

  • Bae, Junhyung
    • Journal of IKEEE
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    • v.25 no.3
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    • pp.548-555
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    • 2021
  • This paper outlines the basic concepts, approaches and research trends of fault diagnosis and fault tolerant control applied to industrial processes, facilities, and motor drives. The main role of fault diagnosis for industrial processes is to create effective indicators to determine the defect status of the process and then take appropriate measures against failures or hazadous accidents. The technologies of fault detection and diagnosis have been developed to determine whether a process has a trend or pattern, or whether a particular process variable is functioning normally. Firstly, data-driven based and model-based techniques were described. Secondly, fault detection and diagnosis techniques for industrial processes are described. Thirdly, passive and active fault tolerant control techniques are considered. Finally, major faults occurring in AC motor drives were listed, described their characteristics and fault diagnosis and fault tolerant control techniques are outlined for this purpose.

Development of DC Arc Generator to protect against Malfunctions and Fires caused by Arcing (아크 발생에 따른 고장 및 화재를 보호하기 위한 직류 아크 Generator 개발)

  • Yoon, Yongho
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.21 no.6
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    • pp.123-128
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    • 2021
  • As the spread of DC power distribution systems increases, the occurrence of failures and fire accidents are also increasing. In particular, the ESS fire accident, which is a component of the smart grid, and the fire accident of the solar power system, which is a direct current system, are caused by problems in the electrical connection between system components as the supply of new and renewable energy rapidly increases and old facilities increase. An arc that can cause a direct fire by releasing the induced light and heat has been pointed out as one of the causes of fire. Therefore, the problem of such an arc defect is that it is impossible to block an arc accident in advance with the existing overcurrent circuit breaker and earth leakage circuit breaker. In this paper, we intend to develop a test equipment that satisfies international standardization and to develop a DC arc generator to protect against failure and fire caused by arcing.

Safety Schematic Diagram and Sequence of Heater in FPD Wet Equipment (FPD 장비 습식공정에서의 안전한 히터 공급 계통도 및 제어 회로)

  • Yoo, Heung-Ryol;Son, Yung-Deug
    • Journal of IKEEE
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    • v.23 no.1
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    • pp.107-111
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    • 2019
  • In FPD WET equipment, heaters are used a lot. There are many electric accidents caused by short circuit and overheating due to the use of heater, so it is necessary to have a safe electric system and interlock. Therefore, in this paper, we propose an electrical schematic and interlock for FPD WET equipment. In this paper, a hardware interlock such as a level sensor, an overheat protector, and an SSR heater sink is inserted, and the electric system is composed of ELB - MC - SSR - EOCR - heater. When the interlock occurs, the magnetic contactor (MC) is turned off and the power of the heater is cut off.EOCR, an electric overcurrent protection device, has an interlock to shut down the MC when there is an abnormality in the heater while checking the overcurrent, undercurrent and disconnection. These circuit configurations and interlocks are likely to be useful not only for WET equipment but also for any equipment in which the heater is placed.

Smart Camera Technology to Support High Speed Video Processing in Vehicular Network (차량 네트워크에서 고속 영상처리 기반 스마트 카메라 기술)

  • Son, Sanghyun;Kim, Taewook;Jeon, Yongsu;Baek, Yunju
    • 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.

Study of the Risk of Ignition due to Internal Combustion Engines in Areas with Potentially Explosive Gas Atmospheres (잠재적 폭발위험장소에서 내연기관에 의한 점화 위험성에 관한 연구)

  • Kim, Yun Seok;Rie, Dong Ho
    • Fire Science and Engineering
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    • v.30 no.5
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    • pp.1-8
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    • 2016
  • Safety management in hazardous areas with potentially explosive gas atmospheres (here in after referred to as hazardous areas) in large scale facilities dealing with combustible or flammable materials at home and abroad is very important (significant) for the coexistence of the company and local society based on business continuity management (BCM) and reliance. For the safety management in hazardous areas, two systems are mainly used: (1) the control system for the prevention of combustible or flammable substances and (2) the explosion proof system for the elimination of ignition sources when flammable gases are leaked to inhibit the transition to fire or explosion accidents. While technology and regulations on explosion proof facilities or devices for electrical ignition sources are well developed and defined, those for thermal ignition sources need to be more developed and established. In this study, the internal combustion engine in hazardous areas was investigated to determine the risk of ignition. For this purpose, document searches were conducted on the relevant international standards and accidents cases and risk analysis reports. In addition, this study assessed the application cases of the diesel engine's safety equipment, such as spark arresters regarding the site of process safety management (PSM) system in central Korea. To practically apply these results to the hydrocarbon industry, the safety management method for explosion prevention in hazardous areas was provided by risk identification for ignition sources of internal combustion engines, such as diesel engines.

Encoder Type Semantic Segmentation Algorithm Using Multi-scale Learning Type for Road Surface Damage Recognition (도로 노면 파손 인식을 위한 Multi-scale 학습 방식의 암호화 형식 의미론적 분할 알고리즘)

  • Shim, Seungbo;Song, Young Eun
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.2
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    • pp.89-103
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    • 2020
  • As we face an aging society, the demand for personal mobility for disabled and aged people is increasing. In fact, as of 2017, the number of electric wheelchair in the country continues to increase to 90,000. However, people with disabilities and seniors are more likely to have accidents while driving, because their judgment and coordination are inferior to normal people. One of the causes of the accident is the interference of personal vehicle steering control due to unbalanced road surface conditions. In this paper, we introduce a encoder type semantic segmentation algorithm that can recognize road conditions at high speed to prevent such accidents. To this end, more than 1,500 training data and 150 test data including road surface damage were newly secured. With the data, we proposed a deep neural network composed of encoder stages, unlike the Auto-encoding type consisting of encoder and decoder stages. Compared to the conventional method, this deep neural network has a 4.45% increase in mean accuracy, a 59.2% decrease in parameters, and an 11.9% increase in computation speed. It is expected that safe personal transportation will be come soon by utilizing such high speed algorithm.

A Study on Characteristics and Modeling of CMV by Grounding Methods of Transformer for ESS (ESS용 변압기의 접지방식에 의한 CMV 모델링 및 특성에 관한 연구)

  • Choi, Sung-Moon;Kim, Seung-Ho;Kim, Mi-Young;Rho, Dae-Seok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.4
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    • pp.587-593
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    • 2021
  • Since 2017, a total of 29 fire accidents have occurred in energy storage systems (ESSs) as of June 2020. The common mode voltage (CMV) is one of the electrical hazards that is assumed to be a cause of those fire accidents. Several cases of CMV that violate the allowable insulation level of a battery section are being reported in actual ESS operation sites with △-Y winding connections. Thus, this paper evaluates the characteristics of CMV. An ESS site was modeled with an AC grid, PCS, and battery sections using PSCAD/EMTDC software. As a result of a simulation based on the proposed model, it was confirmed that characteristics of CMV vary significantly and are similar to actual measurements, depending on the grounding method of the internal transformer for PCS. The insulation level of the battery section may be severely degraded as the value of CMV exceeds the rated voltage in case of a grounding connection. It was found that the value of CMV dramatically declines when the internal transformer for PCS is operated as non-grounding connection, so it meets the standard insulation level.

Development and Evaluation of an Impulsive Force Test Method for Wearable Airbags (착용형 에어백의 충격력 시험 방법개발 및 평가)

  • Park, Jin-O;Kim, Young-Jin
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.22 no.3
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    • pp.597-602
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    • 2021
  • Even in the era of the 4th industrial revolution, the prevention of industrial accidents is still an important issue in industrial sites. In solving the problem of industrial safety, a product can be difficult to market if there is a lack of standard or method for a reliable performance evaluation. The purpose of this study was to develop and evaluate a test method for a wearable airbag product for protecting the body from falls that was newly developed to respond to fall accidents in industrial sites. As a research method, reliable evaluation standards were developed and applied through four stages of the evaluation and development process (Step 1: Product review, Step 2: Data research, Step 3: Expert meeting, Step 4: Drawing evaluation standard). In addition, the impact force was evaluated according to the developed evaluation standard. The fall impact force obtained through the evaluation showed a reduction effect of approximately 96% compared to the existing impact force. Therefore, the fall impact force was reduced significantly when the airbag was applied. This will enable new convergence products to be launched on the market and produce an environment where industrial workers can work safely.