Li L.,University of Maryland University College |
Li L.,Shenyang Fire Research Institute |
Sunderland P.B.,University of Maryland University College
Fire Safety Journal | Year: 2013
Laminar smoke points are important fuel properties for understanding soot processes in fires and flames. Several past studies have measured laminar smoke points of fuel-fuel and fuel-inert mixtures, but scaling laws for these smoke points have been lacking and thus are considered here. To supplement published data from 8 past studies, smoke points are measured for ethylene-inert mixtures. The resulting dataset includes 160 smoke points for fuel-fuel mixtures and 78 for fuel-inert mixtures. For fuel-fuel mixtures, the most successful scaling equates mixture smoke point to the reciprocal of the sum of the constituent mass fractions divided by their smoke points. This scaling is also reasonably successful for fuel-inert mixtures (except those involving Ar) when infinite smoke points are assumed for the inerts. The effectiveness ranking of the inerts to increase smoke points is, by volume: SO2>CO 2>N2>Ar>He, and by mass: He>CO 2≈SO2>N2>Ar. Argon's unusual behavior and low effectiveness is attributed to its low heat capacity. © 2013 Elsevier Ltd. All rights reserved.
Wen-Qing W.,Shenyang Fire Research Institute |
Xiao-Lu L.,Shenyang Fire Research Institute |
Xin-Min D.,Shanghai Sensorlead Technology Co.
Proceedings - 7th International Conference on Intelligent Computation Technology and Automation, ICICTA 2014 | Year: 2015
In order to keep a low false alarm rate of 1/year. kilometre, and in order to launch the fire alarm correctly in the initial stage of such a fire as occurred in a car, a method of threshold selection for a fire alarm system particularly applied in traffic tunnels is discussed in this thesis. Each fire alarm detector randomly collects environmental temperature rise gradients (TRG) and the probability that thus-collected TRG is higher than the lower limit of fire alarm threshold shall be lower than 3 x10-10, the upper limit of fire alarm threshold is defined as the minimum TRG corresponding to a fire with a heat release rate of no less than 1.2MW in the related tunnel. The author has given a detailed description of tunnel fire validation testing and methods for data collection, analysis and statistics in an operating tunnel. The method for rational selection of fire alarm threshold has a universal significance to the further improvement of reliability and practicality of a fire alarm system in traffic tunnels. © 2014 IEEE.
Wang L.T.,Shenyang Fire Research Institute |
Gao W.,Key Laboratory of Fire Scene Investigation and Evidence Identification
Advanced Materials Research | Year: 2012
When fire breaks out, the gas composition and concentration as well as smoke concentration of burning part vary from those in normal environment. The gas and smoke absorbed during solidification of short circuited melted mark occurred in such environment will certainly have an effect on grain shape, grain size, holes distribution and impurity element distribution of organization of melted mark. The gas in the environment has a certain influence on the organization of short circuited melted mark, but the influence is smaller than that of smoke. The reason may be that the gas is mingled with certain amount of tiny smoke particles inevitably which play a role in the solidification of melted mark. Compared with short-circuit samples in normal atmosphere, carbon content of short-circuit samples increases and oxygen content decreases in the environment of smoke. © (2012) Trans Tech Publications, Switzerland.
Meng Q.S.,Shenyang fire research institute |
Meng Q.S.,Key laboratory of fire scene investigation and evidence identification
Applied Mechanics and Materials | Year: 2014
This paper described the microstructure feature of the first short circuit and the second short circuit of copper wires in the electrical equipment line fire. The cause of fire is evaluated and analyzed by the difference in microstructure between the first short circuit and the second short circuit of copper wire. It would provide scientific and favorable evidence for the department of fireman to clear up a case of fire. © (2014) Trans Tech Publications, Switzerland.
Zheng W.,Shenyang Fire Research Institute |
Zhang X.,Shenyang Fire Research Institute |
Wang Z.-F.,Shenyang Fire Research Institute
Procedia Engineering | Year: 2016
A performance experimental study is made with regard to fire detection and fire extinguishing systems installed in a subway train in order to verify the response performance of a fire detection system and the fire suppression efficacy of a fire extinguishing system, thereupon researches on fire prevention and control in relevant subway train being initiated. © 2016 The Authors.
Zhang J.,Shenyang Fire Research Institute |
Wang J.,Shenyang Fire Research Institute
Lecture Notes in Electrical Engineering | Year: 2014
Confidentiality is an important issue when digital images are transmitted over public networks. Conventional encryption techniques such as DES, AES, IDEA, and RSA are not suitable for image cipher in the aspect of efficiency. A novel chaos-based cipher with permutation-diffusion architecture is proposed in this paper for secure and efficient image protection. In permutation stage, discretized Baker map is employed to disturb the high correlation among adjacent pixels. The relationship between the cipher image and plain image are confused by using logistic map in diffusion stage. To enhance the diffusion effect and further the overall security level of the cryptosystem, a chaotic orbit perturbation mechanism is introduced in diffusion stage by perturbing the control parameter of the employed chaotic system according to the cipher-pixel. Experimental results suggest that the proposed image cryptosystem provides a good candidate for secure image transmission applications. © Springer-Verlag Berlin Heidelberg 2014.
Wang Y.Y.,Shenyang Fire Research Institute
Applied Mechanics and Materials | Year: 2013
With the purpose of accurately and reliably making a forecast on fire, it is necessary to study the scattering properties of the early smoke particles. Based on the laser scattering principle of smoke particles, a device is designed in combination with aspiration system, semiconductor laser of different wavelength and spectral photoelectric receiving tube as well as the flexible structure and signal processing methods, so as to implement the function of acquiring the laser scattering intensity data of smoke particles from multiple angles. In this paper, through a comparative analysis, the basic data related to the smoke particle detection algorithms is obtained. © (2013) Trans Tech Publications, Switzerland.
Meng L.,Shenyang Fire Research Institute |
Hulin S.,Shenyang Fire Research Institute |
Jun W.,Shenyang Fire Research Institute |
Qingbo M.,Shenyang Fire Research Institute
International Journal of Digital Content Technology and its Applications | Year: 2011
In this paper, a hybrid location method is proposed to track the walking firefighter continuously in an indoor environment using inertial sensors. The software of location system includes gait phase segmentation and recognition, step length estimation algorithm, motion orientation calculation. The hardware of location system is portable and low-cost. Experimental results showed a reliable performance. At last, the future work is proposed for the improving the system performance.
Zhao Y.,Shenyang Fire Research Institute
Advanced Materials Research | Year: 2013
The paper discussed the main design philosophy of alarm controllers in detection and alarm systems for combustible and toxic gases according to content of national standard, GB 16808-2008. The content of this paper is mainly divided into two parts, program of software and development of hardware. In addition, some key points and problems which should be paid attention to in design and development stage of new product are summarized, including EMC performance, immunity to environment interference and so on. © (2013) Trans Tech Publications, Switzerland.
Zhang J.,Shenyang Fire Research Institute
Proceedings - 2015 IEEE International Conference on Computational Intelligence and Communication Technology, CICT 2015 | Year: 2015
In recent years, chaos-based image cipher has been widely studied and a growing number of schemes based on permutation-diffusion architecture have been proposed. However, recent studies have indicated that those approaches based on low-dimensional chaotic maps/systems have the drawbacks of small key space and weak security. In this paper, a security improved image cipher which utilizes cat map and hyper chaotic Lorenz system is reported. Compared with ordinary chaotic systems, hyper chaotic systems have more complex dynamical behaviors and number of system variables, which demonstrate a greater potential for constructing a secure cryptosystem. In diffusion stage, a plaintext related key stream generation strategy is introduced, which further improves the security against known/chosen-plaintext attack. Extensive security analysis has been performed on the proposed scheme, including the most important ones like key space analysis, key sensitivity analysis and various statistical analyses, which has demonstrated the satisfactory security of the proposed scheme. © 2015 IEEE.