• 정보처리학회논문지B
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• 제16B권6호
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• pp.463-470
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• 2009

본 논문은 기존의 센서 기반 화재 감지기가 넓은 장소와 개방된 공간에서 성능이 저하되는 단점을 보완하기 위하여 카메라 영상을 이용한 화재 불꽃 감지 알고리즘을 제안한다. 기존의 연구에서는 다수의 휴리스틱한 정보를 이용하거나 속도가 느린 문제점을 보여주었다. 이를 해결하기 위하여, 통계적인 값들을 사용했으며 속도를 개선하기 위해 블록 단위로 처리하였다. 먼저 입력된 영상에서 배경 모델과 불꽃 색상 모델 을 이용하여 화재 후보 영역을 추출한다. 그 후 후보 블록에 대하여 시간축 상에서의 명도 변화, 웨이블릿 계수 변화, 모션 변화를 추출하여 확 률 모델을 생성하며, 생성된 모델들을 퍼지 로직의 멤버십 함수로 사용하였다. 마지막으로 역퍼지(defuzzification) 과정을 통해 최종 결과 함수를 생성하고 이로부터 불꽃 발생 확률값을 예측하였다. 실험에서는 제안한 화재 불꽃 감지 알고리즘을 성능이 가장 좋다고 알려진 Toreyin의 알고리즘과 비교하여 성능이 개선되었음을 보여주고 있다.

• 한국전자통신학회논문지
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• 제9권9호
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• pp.977-982
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• 2014

본 논문에서는 고화질 IP 카메라로부터 입력되는 영상으로부터 실시간으로 화염을 검출할 수 있는 시스템을 제안한다. 먼저 FFmpeg 라이브러리를 이용하여 비디오 파일을 오픈하는 것처럼 IP 카메라로부터 전송되는 RTSP 스트림을 직접 오픈한다. 두 번째는 입력영상으로부터 혼합 가우시안 모델을 이용하여 배경영상을 추출한다. 그 다음에는 입력 영상과 배경영상간의 차신호로부터 전경영상을 구한다. 분리된 전경영상은 수학적 모폴로지 연산을 거쳐 후보영역으로 간주한다. 후보영역의 색정보와 화염의 동적 특성을 분석하여 최종적으로 화염을 검출한다. 실험 결과를 통하여 제안하는 방법이 화염을 검출하는 데 효과적인 것을 보인다.

• 인터넷정보학회논문지
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• 제14권2호
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• pp.45-51
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• 2013

본 논문에서는 자외선(UV, ultraviolet) 및 적외선(IR, infrared) 센서를 결합함으로서 불이 연소하면서 방출하는 빛의 파장을 활용한 영상신호를 검출하는 결합형 불꽃영상 검출시스템은 적외선 센서와 자외선 센서 기반의 신호처리 알고리즘 설계방안을 제안한다. 또한, 설계한 듀얼모드인 결합형 불꽃영상 검출시스템은 단독형 적외선 또는 자외선 센서 기반의 영상검출 알고리즘의 검출 성능결과를 비교한다.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제12권3호
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• pp.1301-1314
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• 2018

In this paper, we present a low-cost fire detection system using a thermal camera and a smartphone. The developed system collects thermal and RGB videos from the developed camera. To detect fire, candidate fire regions are extracted from videos obtained using a thermal camera. The block mean of variation of adjacent frames is measured to analyze the dynamic characteristics of the candidate fire regions. After analyzing the dynamic characteristics of regions of interest, a fire is determined by the candidate fire regions. In order to evaluate the performance of our system, we compared with a smoke detector, a heat detector, and a flame detector. In the experiments, our fire detection system showed the excellent performance in detecting fire with an overall accuracy rate of 97.8 %.

• 해양환경안전학회지
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• 제25권4호
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• pp.476-481
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• 2019

화재의 초기 검출은 인명과 재화의 손실을 최소화하기 위한 중요한 요소이다. 불꽃과 연기를 신속하면서 동시에 검출해야 하며 이를 위해 영상 기반의 화재 검출에 관한 연구가 다양하게 진행되고 있다. 기존의 화재 검출은 불꽃과 연기의 특징을 추출하기 위해 여러 알고리즘을 거쳐서 화재의 검출 유무를 판단하므로 연산량이 많이 소모되었으나, 딥러닝 알고리즘인 합성곱 신경망을 이용하면 별도의 과정이 생략되므로 신속하게 검출할 수 있다. 본 논문에서는 선박 기관실에서 화재 영상을 녹화한 데이터로 실험을 수행하였다. 불꽃과 연기의 특징을 외각 상자로 추출한 후 합성곱 신경망 중 하나인 욜로(YOLO)를 이용하여 학습하고 결과를 테스트하였다. 실험 결과를 검출률, 오검출률, 정확도로 평가하였으며 불꽃은 0.994, 0.011, 0.998, 연기는 0.978, 0.021, 0.978을 나타내었고, 연산시간은 0.009s를 소모됨을 확인하였다.

• Journal of Advanced Marine Engineering and Technology
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• 제10권3호
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• pp.107-118
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• 1986

The presenet research attempts to examine the combustion characteristics and the structure of the flame in turbulent premixed flames and thus enhance the combustion performance that leads to the design of the effective combustion system (untilizing LNG). Following experimental investigations for several stabilized premixed flames were attempted to identify the interactive mechanism between flame structures and flow fields; Visualization by Schlieren method, measurement of flow velocity by LDV, detection of ion current by ion probe, measurement of fluctuating temperature by thermocouple having compensation circuit, average values with respect to time of fluctuating amount for flow velocity, temperature, ion current, etc., variable RMS values, PDFs, autocorrelation, crosscorrelation, spatial macroscale, power spectra, and velocity scale. Continuing the authors published studies whose flame dominated by coherent structures and the characteristics of combustion reaction for irregular three dimensional flame and stabilized flame by step were investigated with obtained experimental quantities. Results of this research are following : The most turbulent flames support the structure of a Wrinkled laminar flame or laminar flamelets. It also observed that combustion reaction is related to small tubulence microscales of the turbulent flow fields closly.

• Structural Engineering and Mechanics
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• 제70권6호
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• pp.649-659
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• 2019

Vibration-based structural damage detection through optimization algorithms and minimization of objective function has recently become an interesting research topic. Application of various objective functions as well as optimization algorithms may affect damage diagnosis quality. This paper proposes a new damage identification method using Moth-Flame Optimization (MFO). MFO is a nature-inspired algorithm based on moth's ability to navigate in dark. Objective function consists of a term with modal assurance criterion flexibility and natural frequency. To show the performance of the said method, two numerical examples including truss and shear frame have been studied. Furthermore, Los Alamos National Laboratory test structure was used for validation purposes. Finite element model for both experimental and numerical examples was created by MATLAB software to extract modal properties of the structure. Mode shapes and natural frequencies were contaminated with noise in above mentioned numerical examples. In the meantime, one of the classical optimization algorithms called particle swarm optimization was compared with MFO. In short, results obtained from numerical and experimental examples showed that the presented method is efficient in damage identification.

• 대한기계학회논문집B
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• 제24권6호
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• pp.769-776
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• 2000

Visible spectral characteristics of cross-sectional emissions from a partially premixed methane/air and propane/air flames have been investigated. An optical train with a two-axis scanning mirror system was used to record line-of-sight emission spectra from 354nm to 618nm, and inversion technique was adapted to obtain cross-sectional emission spectra. By analyzing the reconstructed emission spectra, cross-sectional intensities of CH and $C_2$ radicals were separated from the background emissions. The blue flame edge and yellow flame edge were also obtained by image processing technique for edge detection with color photograph of flame. These edges were compared with radial distributions of CH, $C_2$ radicals and background emissions. The CH radicals were observed at blue flame edge. The background emissions were generated by soot precursor at upstream of flame and by soot at downstream of flame. The $C_2$ radicals in propane/air flame were observed more than those in methane/air flame.

• 한국안전학회지
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• 제32권2호
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• pp.38-45
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• 2017

This paper is an experimental study to find an optimal detection method for detecting fire early in a rack-type warehouse stored with goods. In this study, we constructed rack-type structure with the fourth floor of 13.5 m high and conducted fire experiments which were to measure flow of heat/smoke in rack-type structure and response time of fire detectors. The detectors used at experiments were fixed temperature type detectors, rate of rise detectors, photoelectric smoke detectors, air sampling smoke detectors and flame detectors. The used ignition sources are n-heptane fire for response of heat detection and cotton fire for response of smoke detection. The fixed temperature type detectors, rate of rise detectors and photoelectric detectors were installed to every rack level respectively. The results show that the rate of rise detector should be installed every 2 levels and photoelectric smoke detector should be installed every 4 levels for the early stage fire detection. Air sampling smoke detectors can detect fire early in response to control of sensitivity, but there is a problem in false alarm. The fixed temperature detector is not suitable for early stage fire detection in warehouse and flame detector not worked if flame is not visible, so it need to install combination with other detector.

• Journal of Mechanical Science and Technology
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• 제19권12호
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• pp.2197-2204
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• 2005

The combination of Gas chromatography (GC) for separation and Flame Ionization Detection (FID) for detection and identification of the components of a mixture of compounds is a fast and strongly proved method of analytic chemistry. The objective of this research was to design a combined High-speed miniature screening Gas chromatograph along with a Flame Ionization Detector for quick, quantitative and qualitative analysis of gas components. This combined GC-FID system is suitable to detect the volatile and semi-volatile hydrocarbons present in a gas mixture. The construction made it less expensive, easy to use and movable. The complete gas path was developed. On/off valves, temperature and flow sensors and their interface electronics were used for controlling purpose. A Microcontroller was programmed to measure the temperature and gas flow using the sensors and to control and regulate them using the electronics and valves. A pocket PC with its touch screen served as a user interface for the system. Software was developed for the pocket PC, which makes the communication possible with the Microcontroller. The system parameters can be indicated in the Pocket PC as simple text and also the analysis result can be displayed.