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Luoyang, China

Zhang L.,National University of Defense Technology | Liang D.,Unit 63891 of PLA | Yao M.,Unit 63892 of PLA | Zhang M.,Unit 63892 of PLA | Zhang L.,Unit 63891 of PLA
Hongwai yu Jiguang Gongcheng/Infrared and Laser Engineering

As the influence of background radiation is not considered, traditional operating range equation of infrared search and track system (IRST) has a limit. In order to complete the equivalent calculation of operating range of IRST on small dynamic target rapidly in various meteorological and flight conditions, the operating range model on point target of IRST was derived in the sky background. Based on the equation, the operating range of one IRST on the target drone in all kinds of meteorological conditions was calculated. In addition, the equation was validated by the data of target drone flight test and it is proved that the equation is correct and can be used to the equivalent calculation of operating range of IRST. Finally, the operating range of IRST on one kind of missile under different flight and specifically meteorological conditions was calculated based on the equation. Source

Yang X.,Unit 63892 of PLA | Yang X.,Academy of Equipment Command and Technology | Yan L.,Unit 63892 of PLA | Zeng L.,Academy of Equipment Command and Technology
Information Sciences

In practice, many practical problems occur in uncertain environments, especially in situations that involve human subjective evaluation such as that in the analytic hierarchy process (AHP). This paper presents a practical multi-criteria group decision-making method for decision making under uncertainty. To handle the randomness and fuzziness of individual judgments, the normal Cloud model, group decision-making technique, and the Delphi feedback method are adopted. In the proposed Cloud Delphi hierarchical analysis (CDHA), experts are asked to express their judgments using interval numbers. Individual fuzziness and randomness are then mined from the interval-value comparison matrices. Subsequently, the interval-value pairwise comparison matrices are converted into the corresponding Cloud matrices, and the one-iteration Delphi process is executed to diminish individual judgment mistakes. The individual Cloud weight vectors are calculated using the geometric mean technique and are finally weighted to form the group Cloud weight vector. A simple case study that involved reproducing the relative area sizes of six provinces in China shows that the CDHA method can effectively reduce mistakes and improve decision makers' judgments in situations that require subjective expertise and judgmental inputs. In addition, a practical decision-making problem in which houses are ranked by home buyers shows that the proposed method is effective when applied to complex, large, multidisciplinary problems with considerable uncertainties. © 2012 Elsevier Inc. All rights reserved. Source

Liu Y.,Henan Polytechnic University | Wang Y.,Unit 63892 of PLA | Meng F.,Henan Polytechnic University
Bandaoti Guangdian/Semiconductor Optoelectronics

The non-linearity and dispersion characteristics of photonic crystal fiber (PCF) were investigated theoretically by adopting the multipole method. The numerical simulation results show that the two approaches can not only evidently increase the non-linearity of PCF, but also effectively extend the zero-dispersion wavelength λ0 in short-wavelength direction: one way is to decrease the hole diameter d but under the same ratio d/Λ; the other way is to increase the ratio d/Λ but under the same hole diameter d. The high non-linearity and flexible dispersion characteristics of PCF can provide preconditions for broadband and visible supercontinuum generation. Source

Li J.,State Key Laboratory of Complex Electromagnetic Environment Effect on Electronics Information Systems | Zeng Y.,State Key Laboratory of Complex Electromagnetic Environment Effect on Electronics Information Systems | Zhou B.,Unit 63892 of PLA | Fu H.,Unit 63892 of PLA
Beijing Hangkong Hangtian Daxue Xuebao/Journal of Beijing University of Aeronautics and Astronautics

Gesture consistency of airplane target between static and dynamics measurements was studied. The most common coordinate systems in target characteristics measurement were introduced, and the translation relationships were presented. The typical relative position relationship between line of radar sight and airplane target was analyzed, and the flow chart of gesture translation between static and dynamic measurements was derived. A simulation example was given. The airplane flew with a typical path, the radar track of airplane was simulated. The relative position relationship between line of radar sight and airplane target in polarization coordinate system and target coordinate system was derived while airplane is flying. The research can help to compare target characteristics between static and dynamic measurements rightly, and can also guide the dynamic simulation of target characteristics. Source

Zou Q.,Unit 63892 of PLA | Chen Q.,Unit 63892 of PLA | Zhang Y.,Unit 63892 of PLA | Yuan C.,Unit 63892 of PLA | Yuan S.,National University of Defense Technology
Qiangjiguang Yu Lizishu/High Power Laser and Particle Beams

According to the analysis of the characteristics of oscillation paths in the optical cavity of the unstable-resonator DF chemical laser, we point out that different oscillation paths of the upstream and downstream spectra will lead to certain difference in the emission spectrum. The emission spectrum of a continuous-wave DF laser was measured, and it is found that there is no significant difference in the major spectral line components, but some difference in the relative intensity of the upstream and downstream spectral lines. The spectral band of the upstream laser spot, namely the rotational quantum number at maximum relative intensity, tends to be in the direction of the low rotational quantum number for each spectral band. According to the measured spectrum, the cavity temperature and particle population ratio were estimated, and it is found that the average temperature of the upstream cavity is lower than that of the downstream cavity. Source

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