The Second Research Institute of Civil Aviation Administration of China

Chengdu, China

The Second Research Institute of Civil Aviation Administration of China

Chengdu, China

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Chen K.,University of Electronic Science and Technology of China | Zheng M.,University of Electronic Science and Technology of China | Liu W.,The Second Research Institute of Civil Aviation Administration of China | Wu H.,The Second Research Institute of Civil Aviation Administration of China
Dianbo Kexue Xuebao/Chinese Journal of Radio Science | Year: 2012

For the optimization of sparse separable array, a new method based on matrix pencil method is proposed to reduce the number of elements, to solve the element locations and to design the excitations. The pattern of seperable planar array is produced by the pattern of two orthogonal linear array. Firstly, the two desired orthogonal linear array radiation pattern is sampled to form a discrete data set. Secondly, a Hankel Matrix is built and the singular value decomposition (SVD) can be performed. By discarding the insignificant singular values, we obtain an optimal low-rank approximation of the Hankel matrix which corresponds to sparse antenna array. Finally, the generalized eigen-decomposition is employed to calculate the sparse linear array locations and excitations, then the locations and excitations of the sparse separable array are obtained. Simulation results are presented to demonstrate the efficiency of the proposed approach.


Luo Q.,The Second Research Institute of Civil Aviation Administration of China | Zhang Y.-H.,Sichuan University | Cheng H.,The Second Research Institute of Civil Aviation Administration of China | Li C.,Sichuan University
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2014

Delay of flight has been regarded as one of the toughest difficulties in aviation control. How to establish an effective model to handle the delay prediction problem is a significant work. This study proposes NBFDM, a model based on flight information network, which performs flight delay prediction of hub airports according to the state of flight network. The model not only takes into consideration the properties of individual flights, but also considers the related factors which may affect the flight delay. NBFDM first extracts the properties of individual flights as well as the features of flight network before the flight departure, and then apply PCA method to reduce the dimension of feature. After that, the SVR method is employed to obtain the non-linear regression models which are used to predict flight delays. Experiments show that compared with the method that only considers flight properties, the prediction error of proposed model NBFDM is reduced by about 20%.


Cheng H.,The Second Research Institute of Civil Aviation Administration of China | Li Y.-M.,Sichuan University | Luo Q.,The Second Research Institute of Civil Aviation Administration of China | Li C.,Sichuan University
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice | Year: 2014

Delay of flight has been regarded as one of the toughest difficulties in aviation control. How to establish an effective model to handle the delay prediction problem is a significant work. This study proposes a method to model the arriving flights and a C4.5 based improved algorithm to predict delay, comparing with BayesNet and NaiveBayes approach. Experiments based on a realistic dataset of a domestic airport show that the accuracy of the proposed model approximates 80%, which is further improved than the two Bayes approaches. Furthermore, this study performs additional experiments to analyse the influencing factors.


Zhang S.,South China University of Technology | Wang P.,South China University of Technology | Wu R.,South China University of Technology | Peng H.,The Second Research Institute of Civil Aviation Administration of China | Wu R.,Xinjiang University
Huagong Xuebao/CIESC Journal | Year: 2016

Hydrogen peroxide was used to oxidize pretreated regenerated cellulose to oxidized regenerated cellulose (OGC) with carboxylic content (CC) ranging from 3.2% to 15.6% depending on the H2O2/cellulose molar ratios used, reaction time and the pH. The structure of OGC was characterized by FT-IR, 13C NMR, SEM,BET and XRD. The results revealed that the primary hydroxyl at C6 site in glucose units of regenerated cellulose was selectively oxidized to carboxyl group by H2O2 at the present of copper sulfate, and the notable characteristic peaks of carboxyl groups appeared at 173±2 in the spectra of 13C NMR. SEM revealed that the pretreated regenerated cellulose by alkali solution would increase the fiber diameter and grooves space, resulting in volume expansion of cellulose, and thereby promoting oxidation reaction. BET surface area (SBET) and adsorption pore volume (Vp) of OGC 15.6 increased from 10.12 m2·g-1 to 62.45 m2·g-1 and 0.0152 cm3·g-1 to 0.0183 cm3·g-1, respectively. The crystallinity of OGC showed increasing with the increase of CC, which was due to partial loss of the disordered regions during the washing process because of their increased water-solubility. By TG, there was a reduction in thermal stability in parallel with the increase in CC of the samples, while exhibited high char yields. These changes could be attributed to a reduction in degree of polymerization and the increment of CC. The results demonstrated that the cellulose was selectively oxidized to carboxyl group by H2O2, and the properties of OC were depended on the CC. The effect of carbonization agent type on the flame retardant properties of MFAPP/EP was investigated. It revealed that when OGC15.6 (6.25%) acted as carbonization agent, the epoxy resin achieved a UL-94 V0 classification with LOI of 27.2%. The flame retardant properties of MFAPP/EP by OGC15.6 were better than those of GC and pentaerythritol. The adsorption capacity of OGC for Cu2+ and Pb2+ ions from aqueous single metal solutions was obtained by analyzing concentration determined by atomic absorption spectroscopy. These samples showed maximum adsorption capacities for Cu2+ and Pb2+ ions ranging from 4.894 to 24.426 mg·g-1 and 5.845 to 71.833 mg·g-1, respectively. The OGC15.6 showed larger maximum adsorption capacities than GC. The result illuminated that OGC could be applied to flame retardant EP and metal ions adsorption due to the introduction of carboxylic group. © All Right Reserved.


Qiu R.,Southwest Jiaotong University | Zhu F.,Southwest Jiaotong University | Gou J.,Southwest Jiaotong University | Ye J.,The Second Research Institute of Civil Aviation Administration of China | Yang X.,The Second Research Institute of Civil Aviation Administration of China
Gaodianya Jishu/High Voltage Engineering | Year: 2015

In order to theoretically analyze and calculate induced current on cable caused by space electromagnetic field coupling, we obtained the analytic expression of the induced current for different terminal loads of cable by using the transmission line model with a distributed source of aerial shielded cable-ground circuit. Then we analyzed the resonance mechanism of induced current, and acquired the relationship between resonance frequency and cable's length. Additionally, we discussed the relationship among induced current resonance, ground conductivity, and cable's overhead height. The results show that, when resonance occurs in the induced current, its amplitude increases with the cables-ground circuit's time constant. Under preconditions including earth conductivity of 0.01 S/m, irradiation wave frequency of 75 MHz, cable radius of 4 mm, height between cable and ground of 1 m, cable length of 2 m, and both ends of cable being overhead, error between the theoretically calculated result and measured result of the cable induced current is below 5 dB. ©, 2015, Science Press. All right reserved.


PubMed | Civil Aviation Administration of China Civil Aviation Hospital, The Second Research Institute of Civil Aviation Administration of China and Civil Aviation Management Institute of China
Type: Journal Article | Journal: Analytical chemistry | Year: 2016

Mental fatigue is characterized by a reduced capacity for work and a loss of capacity to respond to stimulation and is usually accompanied by a feeling of tiredness and drowsiness. Mental fatigue at work is a serious problem and can raise safety concerns especially in the transportation system. It is believed that mental fatigue is a direct or contributing cause of road and air related accidents and incidents. Psychological studies indicate that fatigue results in reduced work efficiency, alertness, and impaired mental performance. However, its underlying biochemical mechanisms are poorly understood. We hypothesized that the human body is an integrated system, and mental fatigue results in changes not only in psychology but also in biochemistry of the human body. These biochemical changes are detectable in metabolites. We employed global metabolomic profiling methods to screen biochemical changes that occur with mental fatigue in air traffic controllers (ATCs) in civil aviation. A total of 45, all male, ATCs (two batches) were recruited as two mental fatigue groups and 23 executive staff acted as a control group for this study. The volunteers urine samples were collected before and after their work. The samples were analyzed with liquid chromatography/mass spectrometry equipped with a polar, a weak polar, and a nonpolar column, respectively. Three candidate biomarkers were selected on the basis of statistical significance, coefficient of variance, and compared with data of the three groups. The results suggest that urine metabolites may provide a complete new clue from biochemistry to understand, monitor, and manage human mental fatigue.


Peng W.,University of Electronic Science and Technology of China | Wang X.-G.,University of Electronic Science and Technology of China | Tang B.,University of Electronic Science and Technology of China | Wu H.-G.,The Second Research Institute of Civil Aviation Administration of China
Dianzi Yu Xinxi Xuebao/Journal of Electronics and Information Technology | Year: 2010

In this paper, based on the Dechirping technique, a new method of measuring relative delays among digital T/R modules for the wideband digital array utilizing wideband LFM pulses is proposed. To enhance radar system's flexibility and extensibility and reduce hardware costs, this method can be realized by software. By using the decimation and FFT algorithm, not only can the measurement method be easier to be implemented for computational efficiency and reduce data rate, but also good measurement precision and real-time performance are achieved, at the same time, all relative delays among multiple digital T/R modules are enabled to be acquired in one measurement process. The performance of the proposed method is analyzed from the theoretical angle and thus some optimal system parameters are determined. The simulation results show the effectiveness and efficiency of the proposed method.


Huang R.,The Second Research Institute of Civil Aviation Administration of China | Peng W.,University of Electronic Science and Technology of China | Li J.,The Second Research Institute of Civil Aviation Administration of China | Wu H.,The Second Research Institute of Civil Aviation Administration of China | Li X.,The Second Research Institute of Civil Aviation Administration of China
Transactions of Nanjing University of Aeronautics and Astronautics | Year: 2016

Due to the particularity of its location algorithm, there are some unique difficulties and features regarding the test of target motion states of multilateration (MLAT) system for airport surface surveillance. This paper proposed a test method applicable for the airport surface surveillance MLAT system, which can effectively determine whether the target is static or moving at a certain speed. Via a normalized test statistic designed in the sliding data window, the proposed method not only eliminates the impact of geometry Dilution of precision (GDOP) effectively, but also transforms the test of different motion states into the test of different probability density functions. Meanwhile, by adjusting the size of the sliding window, it can fulfill different test performance requirements. The method was developed through strict theoretical extrapolation and performance analysis, and simulations results verified its correctness and effectiveness. © 2016, Editorial Department of Transactions of NUAA. All right reserved.


Sun T.,Sichuan Normal University | Chen K.,The Second Research Institute of Civil Aviation Administration of China
Huaxue Gongcheng/Chemical Engineering (China) | Year: 2012

UV unit is one of the important operation units in the ultrapure water production. Due to high energy consumption of usual UV unit, searching a high-efficient energy-saving UV unit becomes one of the hottest research topics nowadays. The TiO2 film was successfully prepared by sol-gel method with tetrabutyl titanate as precursor and ethanol as solvent. The nitrogen-doped TiO2 film was attained by calcinations of TiO2 film through ammoniation at elevated temperature. The photocatalytic activities of synthesized catalysts were examined using ethylene glycol, isopropyl alcohol and urea as model organic contaminants in ultrapure water. The experimental results demonstrate that under the same ultraviolet light radiation, the catalytic effect of nitrogen-doped TiO2 is much better than that of TiO2, and the same oxidation effect can be achieved by either using 185 nm UV lamp only or using the combination of nitrogen-doped TiO2 with 254 nm UV lamp. The application of such technology in ultrapure water purification can greatly reduce the energy consumption and cost of production.


Chen K.,The Second Research Institute of Civil Aviation Administration of China | Sun T.,Sichuan Normal University | Xiang H.,The Second Research Institute of Civil Aviation Administration of China
Canadian Journal of Chemical Engineering | Year: 2016

Due to continued concern about effects of tetraethyl lead (TEL) emission on the environment and human health, the complete removal of TEL from aviation gasoline (avgas) is a desirable pursuit. In order to maintain high antiknock performance of avgas, an advanced adsorption method was developed using 5A zeolite to remove linear and monobranched alkane from avgas for octane number enhancement. An experimental study of single, binary, and quaternary adsorption of octane isomers on a fixed bed reactor was performed in this work. The effects of partial pressure, operating temperature, and initial mixture composition on breakthrough curves and sorption selectivity were thoroughly studied. At fixed partial pressure, normal octane was the strongest-adsorbed component, followed by 2-methylheptane, 2, 5-dimethylhexane, and 2, 2, 4-trimethylpentane. Adsorption capacity of all components increased with increased partial pressure and decreased with increased operating temperature. However, for all binary mixtures studied in this work, the sorption selectivity decreased as total pressure increased. At equimolar concentrations the normal and monobranched isomers were preferentially adsorbed, while when the volume percentages of the isomers were different, the adsorption of the isomer with the higher volume ratio was favoured. The quaternary breakthrough curves for octane isomers at 473K with each component having partial pressure of 0.15kPa also indicated the feasibility of simultaneous removal of normal and monobranched isomers from a multiple-component mixture by this 5A zeolite. © 2016 Canadian Society for Chemical Engineering.

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