Fusion Detection Algorithm for Infrared Dim Target based on Temporal-Spatial Domain Accumulation and Difference

Jianfeng Wu,Shucai Huang,Hongxia Kang,Yu Zhong 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.11

Aiming at the problem of the dim target real-time detection in Infrared search and track (IRST) systems, a fusion detection algorithm for infrared dim target based on temporal-spatial domain accumulation and difference is proposed. The proposed algorithm suppresses background and enhances targets by template filtering and difference processing in space domain, and the image sequences are processed by multi-frame energy accumulation and frame difference methods according to the target’s moving characteristics in time domain. After the fusion segmentation of the temporal and spatial processing results with definite rule, the target can be detected by the relation of the possible target’s position in adjoining frames according to target’s moving continuity and regularity. Experimental results show that the proposed algorithm enormously increases the target's SNR after the temporal-spatial fusion enhancement, and it has high detection probability and high detecting speed. In the meantime, the algorithm is easy to realize in hardware and can be applied effectively in the real-time target detection of the IRST systems.

Novel spherical TiO2 supported PdNi alloy catalyst for methanol electroxidation

Jianfeng Ju,Donghui Wu,Xi Chen,Yujun Shi,Ping Hua 한국공업화학회 2014 Journal of Industrial and Engineering Chemistry Vol.20 No.4

A novel PdNi/TiO2 electrocatalyst for methanol oxidation is fabricated using spherical TiO2 nanoparticles as support. The structural and electrochemical properties of the PdNi/TiO2 catalyst are characterized by XRD, TEM and electrochemical analysis. The cyclic voltammograms of PdNi/TiO2 catalyst show that there is a large methanol oxidation peak in about 0.882 V that is much bigger than that of the commercial PtRu/C catalyst in 0.7 V. The composite TiO2 material has high catalytic activity without UV light illumination. The electrocatalytic activity and anti-poisoning capability of the PdNi/TiO2 catalyst are promising, which may become a potential candidate for direct methanol fuel cell.

Improved Switching Ripple Suppression Strategy for Multi-Paralleled Grid-Connected Inverters System

Wu Cao,Haotian Kang,Kangli Liu,Shunyu Wang,Jianfeng Zhao,Xiaochun Ji,Jun Zhao 전력전자학회 2019 ICPE(ISPE)논문집 Vol.2019 No.5

The switching operations of inverters in the distributed system inevitably introduce high-frequency harmonics into grid, which may make influences on electrical devices. To address it, this paper proposes a ripple suppression strategy based on active cancellation combined with passive filtering. The active cancellation is realized by carrier-phase-shift (CPS) technique and the passive filtering is achieved by filters. Furthermore, two component-shared LCL-type filters improved by traditional LCL filters are studied from the points of resonance and accuracy of gridinjected current. To valid the effectiveness of the proposed strategy, simulations and experimental test are carried out. The results show that the proposed strategy can effectively suppress high-frequency harmonics and two componentshared LCL-type filters can become promising filters for the multi-paralleled grid-connected inverters.

Stabilization Control Strategy for Shore Power System with Surge Loads Based on Virtual Synchronous Generator

Wu Cao,Kangli Liu,Sheng Xu,Haotian Kang,Jianfeng Zhao 대한전기학회 2019 Journal of Electrical Engineering & Technology Vol.14 No.3

The frequent starting of large capacity lifting machines and other surge ship electrical loads will result in severe impacts on a shipboard power network, such as voltage and frequency fl uctuations. Therefore, a novel stabilization control strategy for shore power systems based on virtual synchronous generator is proposed in this paper, so as to improve the power quality and enhance the stability and reliability of shipboard power networks. In this strategy, a reactive power inertia component is embedded into the virtual synchronous generator aiming at shipboard surge reactive powers. On this basis, a voltage and frequency stability control method is presented to improve the static performances of shore power systems. In addition, a d-q decoupling control scheme in synchronous reference frame for the voltage and current double closed-loop control system is designed, and moreover, the infl uence of diff erent feedback voltages on the output characteristics of shore power supplies is studied. The theoretical analysis, simulation and experiment results show that, the proposed control strategy can eff ectively attenuate the frequency and voltage fl uctuations, eliminate the frequency and voltage steady-state errors, as well as realize the power distribution evenly for modular shore power supplies.

Precise Cutterhead Clogging Detection for Shield Tunneling Machine Based on Deep Residual Networks

Ruihong Wu,Chengjin Qin,Guoqiang Huang,Jianfeng Tao,Chengliang Liu 제어·로봇·시스템학회 2024 International Journal of Control, Automation, and Vol.22 No.3

During the construction process of tunnels, the cutterhead of shield tunneling machines may get cloggeddue to clay adhesion, which may seriously affect the efficiency of the project. Therefore, finding an intelligentdiagnosis method to detect the clogging status is of great importance. In this study, a deep residual network-basedmethod for diagnosing cutterhead clogging on shield tunneling machines is proposed. First, working state data ofthe shield tunneling machine is screened out, and parameters reflecting the clogging state are selected for furtheranalysis. After eliminating extreme outliers, an empirical formula is proposed to label the data. At the same time,several time-domain features of the selected excavation parameters within every five minutes are extracted. Thesefeatures are then fed into the proposed model as the input data to realize clogging detection. Because the originaldataset is imbalanced, the combination of f1-score and accuracy is used to evaluate the performance of the proposedmodel. The results show that the accuracy of the proposed algorithm reaches 95.71%, which is 1.21%, 2.84%,9.84%, 6.04%, and 0.86% higher than the support vector machine-based, random forest-based, AdaBoost-based,extreme gradient boosting-based and deep neural network-based methods. The f1 score of the proposed modelis 0.923, which is also 0.038, 0.042, 0.269, 0.169 and 0.02 higher than those compared methods. Therefore, theproposed deep residual network-based method can accurately detect cutterhead clogging conditions.

Influence of neck width on the performance of ADAS device with diamond-shaped hole plates

Yingxiong Wu,Jianfeng Lu,Yun Chen 국제구조공학회 2020 Structural Engineering and Mechanics, An Int'l Jou Vol.74 No.1

Metallic energy-dissipation dampers are widely used in structures. They are comprised of an added damping and stiffness (ADAS) device with many parallel, diamond-shaped hole plates, the neck width of which is an important parameter. However, no studies have analyzed the neck width’s influence on the ADAS device’s performance. This study aims to better understand that influence by conducting a pseudo-static test on ADAS, with three different neck widths, and performing finite element analysis (FEA) models. Based on the FEA results and mechanical theory, a design neck width range was proposed. The results showed that when the neck width was within the specified range, the diamond-shaped hole plate achieved an ideal yield state with minimal stress concentration, where the ADAS had an optimal energy dissipation performance and the brittle shear fracture on the neck was avoided. The theoretical values of the ADAS yield loads were in good agreement with the test values. While the theoretical value of the elastic stiffness was lower than the test value, the discrepancy could be reduced with the proposed modified coefficient.

Comparison of physicochemical parameters, microbial community composition and flavor substances during mechanical and traditional brewing process of Jiang-flavor baijiu

Cheng Wu,Jianfeng Hu,Dan Xie,Endi Fan,Junlin Yang,Xiaolong You,Pingyan Cheng,Wei Huang,Feng Hu,Diqiang Wang 한국식품과학회 2024 Food Science and Biotechnology Vol.33 No.8

Mechanized, automated and intelligent brewing is an important trend of innovation and transition in Jiang-flavor baijiu industry. In this study, physicochemical parameters, microbial community composition and flavor substances during 3rd round heap fermentation between mechanical and traditional workshop were investigated and compared based on traditional culturable methods, high-throughput sequencing technology and gas chromatography analysis. The dominant bacterial and fungal genera were consistent between the two workshops, but mechanized brewing had a significant impact on the composition of fungal communities. Rhodococcus and Monascus were special genera in mechanical workshop. The interaction relationship between physicochemical parameters and dominant microorganisms in mechanized workshop was different from traditional workshop as well. This study provided a scientific basis for further analyzing the mechanism of mechanized brewing of Jiang-flavor baijiu.

Power Monitor Networked Control Based on DeviceNet Field-bus

Zaiping Chen,Jianfeng Zhang,Chao Jia,Fan Wu 제어로봇시스템학회 2009 제어로봇시스템학회 국제학술대회 논문집 Vol.2009 No.8

In this paper a networked monitor scheme with Powermonitor3000 monitor unit based on the DeviceNetfieldbus is proposed. We adopt SLC5/05 Controller produced by ROCKWELL Automation to controlPowermonitor3000 with DeviceNet fieldbus. Explicit Message mode, which is by M file communication mode, isutilized in this scheme for reading parameters, and this mode is the strongest DeviceNet communication mode. Thenetworked monitor scheme of Powermonitor3000 based on M file under DeviceNet is investigated. The procedure withPowermonitor3000 for online monitor electric transformer under DeviceNet fieldbus is introduced, which provides thereliable support for networked power distribution system and factory automation systems. The experimental results aregiven, in which the correctness and effectiveness of proposed scheme is verified.

Discrimination of American ginseng and Asian ginseng using electronic nose and gas chromatography-mass spectrometry coupled with chemometrics

Cui, Shaoqing,Wu, Jianfeng,Wang, Jun,Wang, Xinlei The Korean Society of Ginseng 2017 Journal of Ginseng Research Vol.41 No.1

Background: American ginseng (Panax quinquefolius L.) and Asian ginseng (Panax ginseng Meyer) products, such as slices, have a similar appearance, but they have significantly different prices, leading to widespread adulteration in the commercial market. Their aroma characteristics are attracting increasing attention and are supposed to be effective and nondestructive markers to determine adulteration. Methods: The aroma characteristics of American and Asian ginseng were investigated using gas chromatography-mass spectrometry(GC-MS) and an electronic nose (E-nose). Their volatile organic compounds were separated, classified, compared, and analyzed with different pattern recognition. Results: The E-nose showed a good performance in grouping with a principle component analysis explaining 94.45% of variance. A total of 69 aroma components were identified by GC-MS, with 35.6% common components and 64.6% special ingredients between the two ginsengs. It was observed that the components and the number of terpenes and alcohols were markedly different, indicating possible reasons for their difference. The results of pattern recognition confirmed that the E-nose processing result is similar to that of GC-MS. The interrelation between aroma constituents and sensors indicated that special sensors were highly related to some terpenes and alcohols. Accordingly, the contents of selected constituents were accurately predicted by corresponding sensors with most $R^2$ reaching 90%. Conclusion: Combined with advanced chemometrics, the E-nose is capable of discriminating between American and Asian ginseng in both qualitative and quantitative angles, presenting an accurate, rapid, and nondestructive reference approach.

The Composition of the Rare Earth Based Conversion Coating Formed on AZ91D Magnesium Alloy

( Menglei Chang ),( Jianfeng Wu ),( Dongchu Chen ),( Shulin Ye ) 한국부식방식학회(구 한국부식학회) 2018 Corrosion Science and Technology Vol.17 No.1

As structural materials, magnesium (Mg) alloys have been widely used in the fields of aviation, automobiles, optical instruments, and electronic products. There are few studies on the effect of coating conditions on the compositional variation during the formation process of the conversion coatings. Rare-earth based conversion coating on AZ91 magnesium alloy was prepared in ceric sulfate and hydrogen peroxide contained solution. The element composition and valence as well as their distribution in the coating were analyzed with energy dispersive X-ray spectroscopy (EDS), Electron probe micro-analyzer (EPMA), X-ray photoelectron spectroscopy (XPS). The effect of treating process on the element composition were also studied. It was found that the conversion coating surface consists of Mg, Al, O, Ce, and the weight content of Ce in the coating was affected by the treating solution concentration and immersion time; the Ce element was distributed in the coating non-uniformly and existed in the form of Ce⁺³ and Ce⁺⁴, while the O element existed in the form of OH^-, O^2-, H₂O. Based on microscopic analysis results, the electrochemical deposition mechanism on the micro-anode and micro-cathode in the process of the coating growth was suggested.