• Title/Summary/Keyword: Flame Features

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Development of Crown Fire Propagation Probability Equation Using Logistic Regression Model (로지스틱 회귀모형을 이용한 수관화확산확률식의 개발)

  • Ryu, Gye-Sun;Lee, Byung-Doo;Won, Myoung-Soo;Kim, Kyong-Ha
    • Journal of the Korean Association of Geographic Information Studies
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    • v.17 no.1
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    • pp.1-12
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    • 2014
  • Crown fire, the main propagation type of large forest fire, has caused extreme damage with the fast spread rate and the high flame intensity. In this paper, we developed the probability equation to predict the crown fires using the spatial features of topography, fuel and weather in damaged area by crown fire. Eighteen variables were collected and then classified by burn severity utilizing geographic information system and remote sensing. Crown fire ratio and logistic regression model were used to select related variables and to estimate the weights for the classes of each variables. As a results, elevation, forest type, elevation relief ratio, folded aspect, plan curvature and solar insolation were related to the crown fire propagation. The crown fire propagation probability equation may can be applied to the priority setting of fuel treatment and suppression resources allocation for forest fire.

Combustion Analysis with CARS Temperature Measurement in a Gas Turbine Combustor (가스터빈 연소기내 CARS 온도측정을 통한 연소해석)

  • Lee, Jong-Ho;Park, Chul-Woong;Han, Yeoung-Min;Ko, Young-Sung;Lee, Su-Yong;Yang, Soo-Seok;Lee, Dae-Sung;Jeon, Chung-Hwan;Chang, Young-June;Shin, Hyun-Dong;Hahn, Jae-Won
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.8
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    • pp.1134-1141
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    • 2003
  • Performance of a gas turbine combustor installed in a test facility has been studied by measuring spatially- and temporally-resolved temperature distributions using multiplex CARS technique. 500 CARS temperatures were determined at each measuring point to obtain a histogram of temperature distribution. Experiments were carried out in the aero-engine combustor sector rig burning standard kerosene fuel. The histograms were obtained around a triple-sector double annular rig running in ground idle conditions, showing features of flow mixing within the rig. The temperature histograms that prove the existence of high temperatures above 1900 K provide us valuable information to improve the design of the combustor structure suppressing NOx generation in turbulent combustion processes. The effects of swirl direction and pre-filmer on gas turbine combustion were investigated. When we installed radial swirls, a large recirculation zone was formed by the fuel module regardless of swirl directions and the pre-filmer installation. It is found that the swirl direction affects the shape of the reverse flow zone, however. Also, an attempt to estimate the flow field and flame structure is made using the histogram of temperature determined with the CARS technique.

Development of Fire Detection Algorithm using Intelligent context-aware sensor (상황인지 센서를 활용한 지능형 화재감지 알고리즘 설계 및 구현)

  • Kim, Hyeng-jun;Shin, Gyu-young;Oh, Young-jun;Lee, Kang-whan
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2015.05a
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    • pp.93-96
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    • 2015
  • In this paper, we introduce a fire detection system using context-aware sensor. In existing weather and based on vision sensor of fire detection system case, acquired image through sensor of camera is extracting features about fire range as processing to convert HSI(Hue, Saturation, Intensity) model HSI which is color space can have durability in illumination changes. However, in this case, until a fire occurs wide range of sensing a fire in a single camera sensor, it is difficult to detect the occurrence of a fire. Additionally, the fire detection in complex situations as well as difficult to separate continuous boundary is set for the required area is difficult. In this paper, we propose an algorithm for real-time by using a temperature sensor, humidity, Co2, the flame presence information acquired and comparing the data based on multiple conditions, analyze and determine the weighting according to fire it. In addition, it is possible to differential management to intensive fire detection is required zone dividing the state of fire.

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Cause Analysis Ignited at a Far Infrared Radiation Heater (원적외선 히터에서 출화된 화재의 원인분석)

  • Kim, Dong-Ook;Choi, Chung-Seog
    • Fire Science and Engineering
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    • v.22 no.2
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    • pp.91-96
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    • 2008
  • This research studied about the cause analysis of fire that was occurred in far infrared rays heater to base on the fire examples. Fire of electric heater was apt to commit error that handled an over-heating accident by judged molten mark in heat ray. Molten mark which was attached in heat ray was appeared to the form of layer short circuit by other metal material, but other metal material was not found beside the ingredient of heat wire which was mixed to an alloy of Fe-Cr-Al according to result of ingredient distribution by SEM/EDX. Also, the result of overheating experiment by layer short circuit and overvoltage showed higher febrility than normal, but there was no possibility of fire occurrence. This paper will be contributed to science for cause analysis of electric fire through analyzing physical, chemical and flame features of burnout heater on the basis of diagnosis of fire that was happened in infrared rays heater.

Selection of a Fire Detector for Wood Cultural Property (목조문화재 건축물 구조에 따른 화재감지기 종류 선정에 관한 연구)

  • Roh, Sam-Kew;Yoon, Hyoung-Uk
    • Fire Science and Engineering
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    • v.30 no.4
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    • pp.88-93
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    • 2016
  • A fire detector installed in wood cultural properties has not have selected the detector type appropriate for the features of cultural properties and the structure of wood fire after the fire in Sungnyemun-Gate since 2008. Applying wooden cultural properties different from the general architecture of the structure and fire characteristics is difficult. Therefore, buildings were classified into four shape types and field survey and wooden architecture structure characteristics to identify the problems of the detectors installed on wooden cultural property buildings. The problems appeared to lack the adaptability to external fire detection sensor selection and missing fire detectors installed in accordance with the place. To solve the problem, the closed and open space of the rooms used a smoke detector, outdoor select flame or fixed temperature linear detector to solve the problem.

Impurity profiling and chemometric analysis of methamphetamine seizures in Korea

  • Shin, Dong Won;Ko, Beom Jun;Cheong, Jae Chul;Lee, Wonho;Kim, Suhkmann;Kim, Jin Young
    • Analytical Science and Technology
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    • v.33 no.2
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    • pp.98-107
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    • 2020
  • Methamphetamine (MA) is currently the most abused illicit drug in Korea. MA is produced by chemical synthesis, and the final target drug that is produced contains small amounts of the precursor chemicals, intermediates, and by-products. To identify and quantify these trace compounds in MA seizures, a practical and feasible approach for conducting chromatographic fingerprinting with a suite of traditional chemometric methods and recently introduced machine learning approaches was examined. This was achieved using gas chromatography (GC) coupled with a flame ionization detector (FID) and mass spectrometry (MS). Following appropriate examination of all the peaks in 71 samples, 166 impurities were selected as the characteristic components. Unsupervised (principal component analysis (PCA), hierarchical cluster analysis (HCA), and K-means clustering) and supervised (partial least squares-discriminant analysis (PLS-DA), orthogonal partial least squares-discriminant analysis (OPLS-DA), support vector machines (SVM), and deep neural network (DNN) with Keras) chemometric techniques were employed for classifying the 71 MA seizures. The results of the PCA, HCA, K-means clustering, PLS-DA, OPLS-DA, SVM, and DNN methods for quality evaluation were in good agreement. However, the tested MA seizures possessed distinct features, such as chirality, cutting agents, and boiling points. The study indicated that the established qualitative and semi-quantitative methods will be practical and useful analytical tools for characterizing trace compounds in illicit MA seizures. Moreover, they will provide a statistical basis for identifying the synthesis route, sources of supply, trafficking routes, and connections between seizures, which will support drug law enforcement agencies in their effort to eliminate organized MA crime.

The Control System of Wood Pellet Boiler Based on Home Networks (홈 네트워크 기반의 펠릿 활용 난방 보일러 제어시스템)

  • Lee, Sang-Hoon
    • Journal of the Institute of Convergence Signal Processing
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    • v.15 no.1
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    • pp.15-22
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    • 2014
  • This paper presents the implementation of a control system of pellet boiler using wood pellet as carbon neutral material. The system also has the additional features to provide remote controlling and monitoring based on home networking technology through either public switched telephone networks or mobile communication networks. It consists of three kinds of sub-modules; a main controller provides basic and additional features such as a setting of temperature, a supplying of wood pellet, a controlling of ignition and fire-power, and a removing of soot. The second is temperature controller of individual rooms which is connected to the main controller through RS-485 links. And interface modules with PSTN and mobile networks can support remote controlling and monitoring the functions. The test results under the heating area of $172m^2$ show a thermal efficiency of 93.6%, a heating power of 20,640kcal/hr, and a fuel consumption of 5.54kg/hr. These results are superior to those of the conventional pellet boilers. In order to obtain the such high performance, we newly applied a 3-step ignition flow, a flame detection by $C_dS$ sensor, and a fire-power control by fine controlling of shutter to our pellet boiler.

The temperature condition for the mylonitization of the Cheongsan granite, Korea (변형된 청산 화강암의 압쇄암화작용시의 변형온도 - 변형된 청산 화강암의 구조 해석 -)

A historical study of the Large Banner, a symbol of the military dignity of the Late Joseon Dynasty (조선 후기 무위(武威)의 상징 대기치(大旗幟) 고증)

  • JAE, Songhee;KIM, Youngsun
    • Korean Journal of Heritage: History & Science
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    • v.54 no.4
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    • pp.152-173
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    • 2021
  • The Large Banner was introduced during the Japanese Invasions of Korea with a new military system. It was a flag that controlled the movement of soldiers in military training. In addition, it was used in other ways, such as a symbol when receiving a king in a military camp, a flag raised on the front of a royal procession, at the reception and dispatch of envoys, and at a local official's procession. The Large Banner was recognized as a symbol of military dignity and training rites. The Large Banner was analyzed in the present study in the context of two different types of decorations. Type I includes chungdogi, gakgi and moongi. Type II includes grand, medium, and small obangi, geumgogi and pyomigi. Each type is decorated differently for each purpose. The size of the flag is estimated to be a square of over 4 ja long in length. Flame edges were attached to one side and run up and down The Large Banner used the Five Direction Colors based on the traditional principles of Yin-Yang and Five Elements. The pattern of the Large Banner is largely distinguished by four. The pattern of large obangi consists of divine beasts symbolizing the Five Directions and a Taoism amulet letter. The pattern of medium obangi features spiritual generals that escort the Five Directions. The pattern of small obangi has the Eight Trigrams. The pattern of moongi consists of a tiger with wings that keeps a tight watch on the army's doors. As for historical sources of coloring for Large Banner production, the color-written copy named Gije, from the collection of the Osaka Prefect Library, was confirmed as the style of the Yongho Camp in the mid to late 18th century, and it was also used for this essay and visualization work. We used Cloud-patterned Satin Damask as the background material for Large Banner production, to reveal the dignity of the military. The size of the 4 ja flag was determined to be 170 cm long and 145 cm wide, and the 5 ja flag was 200 cm long and 175 cm wide. The conversion formula used for this work was Youngjochuck (1 ja =30cm). In addition, the order of hierarchy in the Flag of the King was discovered within all flags of the late Joseon Dynasty. In the above historical study, the two types of Large Banner were visualized. The visualization considered the size of the flag, the decoration of the flagpole, and the patterns described in this essay to restore them to their original shape laid out the 18th century relics on the background. By presenting color, size, material patterns, and auxiliary items together, it was possible not only to produce 3D content, but also to produce real products.