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Classification of Sailboat Tell Tail Based on Deep Learning

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Journal of Ocean University of China 2024年第3期23卷 710-720页

作者： CHANG Xiaofeng YU Jintao GAO Ying DING hongchen LIU Yulong YU Huaming Department of Physical Education Ocean University of ChinaQingdao 266100China College of Big Data Qingdao University of Science and TechnologyQingdao 266061China College of Oceanic and Atmospheric Sciences Ocean University of ChinaQingdao 266100China

The tell tail is usually placed on the triangular sail to display the running state of the air flow on the sail *** is of great significance to make accurate judgement on the drift of the tell tail of the sailboat during sailing for the best sailing *** it is difficult for sailors to keep an eye for a long time on the tell sail for accurate judging its changes,affected by strong sunlight and visual *** this case,we adopt computer vision technology in hope of helping the sailors judge the changes of the tell tail in ease with *** paper proposes for the first time a method to classify sailboat tell tails based on deep learning and an expert guidance system,supported by a sailboat tell tail classification data set on the expert guidance system of interpreting the tell tails states in different sea wind conditions,including the feature extraction *** the expression capabilities that vary with the computational features in different visual tasks,the paper focuses on five tell tail computing features,which are recoded by an automatic encoder and classified by a SVM *** experimental samples were randomly divided into five groups,and four groups were selected from each group as the training set to train the *** remaining one group was used as the test set for *** highest resolution value of the ResNet network was 80.26%.To achieve better operational results on the basis of deep computing features obtained through the ResNet network in the *** method can be used to assist the sailors in making better judgement about the tell tail changes during sailing.

关键词： tell tail sailboat classification deep learning

Effects of carrier-attached biofilm on oxygen transfer efficiency in a moving bed biofilm reactor

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Frontiers of Environmental Science & Engineering 2016年第3期10卷 569-577页

作者： Yanling WEI Xunfei YIN Lu QI hongchen WANG Yiwei GONG Yaqian LUO School of Environment and Natural Resources Renmin University of China Beijing 100872 China

Three laboratory-scale moving bed biofilm reactors （MBBR） with different carrier filling ratios ranging from 40% to 60% were used to study the effects of carrier-attached biofilm on oxygen transfer efficiency. In this study, we evaluated the performance of three MBBRs in degrading chemical oxygen demand and ammonia. The three reactors removed more than 95% of NH4^＋ -N at an air flow-rate of 60L·h^-1. The standard oxygen transfer efficiency （αSOTE） of the three reactors was also investigated at air flow-rates ranging from 60 to 100L·h^-1. These results were compared to αSOTE of wastewater with a clean carrier （no biofilm attached）. Results showed that under. these process conditions, αSOTE decreased by approximately 70% as compared to αSOTE of wastewater at a different carrier-filling ratio. This indicated that the biofilm attached to the cartier had a negative effect on αSOTE. Mechanism analysis showed that the main inhibiting effects were related to biofilm flocculants and soluble microbial product （SMP）. Biofilm flocs could decrease otSOTE by about 20%, and SMP could decrease aαSOTE by 30%--50%.

关键词： carrier biofilm oxygen transfer efficiency moving bed biofilm reactor

Overcoming doping bottleneck by using surfactant and strain

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Frontiers of Materials Science 2011年第4期5卷 335-341页

作者： Junyi ZHU Su-huai WEI National Renewable Energy Laboratory Golden Colorado 80401 USA

Overcoming the doping bottleneck in semiconductors, especially in wide band gap semiconductors, has been a challenge in semiconductor physics for many years. In this paper, we review some recent progresses in enhancing doping by surfactant and strain. We show that surfactant and strain are two effective approaches to enhance dopant solubility in epitaxial growth. The surfactant can introduce an energy level deep inside the band gap, making the host compound less stable, thus lower the formation energy of the intentional dopant. The strain enhanced doping is based on the observation that dopant induces volume change in the host. If the external strain is in the same direction as the dopant induced volume change, the formation energy of the dopant is reduced. This effect can be used to tune doping sites, thus doping type, in a host. A hybrid method to both include strain and surfactant is proposed, which can be a promising general method to further enhance doping.

关键词： semiconductor surfactant strain doping band gap

Concentrated Trading and the Survival of Overconfident Traders

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Acta Mathematicae Applicatae Sinica 2019年第4期35卷 753-760页

作者： huai-nian ZHANG De-qing ZHOU Mathematics School & Institute Jilin University Changchun 130012 China Department of Mathematics and Physics Beijing Institute of Petrochemical Technology Beijing 102617 China School of Finance Central University of Finance and Economics Beijing 100081 China

We build a strategic trading model where the overconfident trader earns more than the rational trader and the mechanism for this result differs from that of Kyle and Wang(1997). In this paper, discretionary and nondiscretionary liquidity traders coexist. The overconfident insider is less worried by the market maker and thus induces a lower liquidity cost. In this way, he attracts all the trading from the discretionary liquidity traders, which enables the survival of the overconfident trader.

关键词： strategic trading concentrated trading overconfidence

Rational design of hydrogels for immunomodulation

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Regenerative Biomaterials 2022年第1期9卷 979-1000页

作者： Wenhuan Bu Yuanhao Wu Amir M.Ghaemmaghami hongchen Sun Alvaro Mata Liaoning Provincial Key Laboratory of Oral Diseases School of StomatologyChina Medical UniversityNo.117Nanjing North StreetHeping DistrictShenyang 110001China Department of Dental Materials School of StomatologyChina Medical UniversityNo.117Nanjing North StreetHeping DistrictShenyang 110001China Department of Center Laboratory School of StomatologyChina Medical UniversityNo.117Nanjing North StreetHeping DistrictShenyang 110001China School of Pharmacy University of NottinghamUniversity ParkNottingham NG72RDUK Biodiscovery Institute University of NottinghamUniversity ParkNottingham NG72RDUK Division of Immunology School of Life SciencesUniversity of NottinghamUniversity ParkNottingham NG72RDUK Terasaki Institute for Biomedical Innovation 1018 Westwood BlvdLos AngelesCA 90024USA Department of Chemical and Environmental Engineering University of NottinghamUniversity ParkNottingham NG72RDUK

The immune system protects organisms against endogenous and exogenous harm and plays a key role in tissue development,repair and *** immunomodulatory biologics exhibit limitations including degradation by enzymes,short half-life and lack of targeting *** or binding these biologics within biomaterials is an effective way to address these *** are promising immunomodulatory materials because of their prominent biocompatibility,tuneability and ***,to take advantage of these opportunities and optimize material performance,it is important to more specifically elucidate,and leverage on,how hydrogels affect and control the immune ***,we summarize how key physical and chemical properties of hydrogels affect the immune *** first provide an overview of underlying steps of the host immune response upon exposure to ***,we discuss recent advances in immunomodulatory strategies where hydrogels play a key role through(i)physical properties including dimensionality,stiffness,porosity and topography;(ii)chemical properties including wettability,electric property and molecular presentation;and(iii)the delivery of bioactive molecules via chemical or physical ***,this review aims to build a conceptual and practical toolkit for the design of immune-instructive hydrogels capable of modulating the host immune response.

关键词： hydrogels immunomodulation physical properties chemical properties

An Improved Daugman Method for Iris Recognition

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Wuhan University Journal of Natural Sciences 2015年第3期20卷 229-234页

作者： PENG Zhiyong WANG hongchen WU Jun LI Jun School of Electrical Engineering and Automation Guilin University of Electronic Technology Guangxi Experiment Center of Information Science Guilin University of Electronic Technology Guangxi Key Laboratory of Automatic Detecting Technology and Instruments Guilin University of Electronic Technology Editorial Board of Geomatics and Information Science of Wuhan University

An improved Daugman iris recognition algorithm is provided in this paper, which embodies in two aspects： 1 Improvement for iris localization and 2 The improvement for both iris encoding and matching algorithms. In Step 1, the localization and shape of the pupil are roughly determined in iris image, which is used as prior knowledge to quickly locate the inner and outer boundary of iris from rough to fine scale. Eyelids, eyelashes areas and the spot in the pupil are automatically detected and removed to improve the localization accuracy. In Step 2, the possible noise from residual eyelashes is further filtered by selecting a ＂pure＂ iris area as a reference and making a validation judgment pixel-wise. Furthermore, the validation flag for each pixel is introduced into the iris encoding and matching computation, as a result, the rejection rate of iris recognition is reduced. Compared with Daugman algorithm, iris recognition test on collected human eye images shows that our proposed algorithm has an obvious improvement both on boosting the speed and reducing the rejection rate.

关键词： iris recognition iris localization iris encoding

3D MHD simulation of the double-gradient instability of the magnetotail current sheet

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Science China(Technological Sciences) 2018年第9期61卷 1364-1371页

作者： DUAN AiYing ZHANG huai LU Hao Yu Key Laboratory of Computational Geodynamics University of Chinese Academy of Sciences State Key Laboratory of Space Weather Chinese Academy of Sciences School of Space and Environment Beihang University

Flapping motion of the current sheet(CS) is an important physical process in the Earth's magnetotail. The magnetic doublegradient model, which includes both the instability and wave modes, offers a reasonable explanation for the exciting and propagation of the flapping wave. In this paper, we apply an advanced numerical magnetohydrodynamic(MHD) scheme(conservation element and solution element(CESE)-MHD) to simulate the magnetic double-gradient instability in an idealized current sheet that mimics the magnetotail configuration. We initialize the simulations with a numerically relaxed magnetotail equilibrium, in which the normal component of the magnetic field has a tailward gradient. It is confirmed in our simulation that the instability develops in the current layer. The growth rate of the instability yielded from the simulation is very close to the prediction of theory, with a relative deviation of only ten percent. The results demonstrate that the CESE-MHD scheme is very powerful in numerical study of the double-gradient mechanism of the CS flapping mode, and can be used for further investigations of the flapping motion in more realistic CS configurations.

关键词： Earth's magnetotail current sheet flapping magnetohydrodynamic numerical simulation

Cryptographic protocol security analysis based on bounded constructing algorithm

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Science in China(Series F) 2006年第1期49卷 26-47页

作者： LI Xianxian huai Jinpeng School of Computer Beihang University Beijing 100083 China

An efficient approach to analyzing cryptographic protocols is to develop automatic analysis tools based on formal methods. However, the approach has encountered the high computational complexity problem due to reasons that participants of protocols are arbitrary, their message concurrent. We propose an efficient structures are complex and their executions are automatic verifying algorithm for analyzing cryptographic protocols based on the Cryptographic Protocol Algebra （CPA） model proposed recently, in which algebraic techniques are used to simplify the description of cryptographic protocols and their executions. Redundant states generated in the analysis processes are much reduced by introducing a new algebraic technique called Universal Polynomial Equation and the algorithm can be used to verify the correctness of protocols in the infinite states space. We have implemented an efficient automatic analysis tool for cryptographic protocols, called ACT-SPA, based on this algorithm, and used the tool to check more than 20 cryptographic protocols. The analysis results show that this tool is more efficient, and an attack instance not offered previously is checked by using this tool.

关键词： cryptographic protocol formal analysis security verification.

Preprocessing photospheric vector magnetograms for nonlinear force-free field extrapolation of the global corona

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Research in Astronomy and Astrophysics 2018年第7期18卷 113-124页

作者： Ai-Ying Duan huai Zhang Key Laboratory of Computational Geodynamics University of Chinese Academy of Sciences SIGMA Weather Group State Key Laboratory for Space Weather National Space Science Center Chinese Academy of Sciences Laboratory for Marine Mineral Resources Qingdao National Laboratory for Marine Science and Technology

Nonlinear force-free magnetic field （NLFFF） extrapolation based on the observed photo- spheric magnetic field is the most important method to obtain the coronal magnetic field nowadays. However, raw photospheric magnetograms contain magnetic forces and small-scale noises, and fail to be consistent with the force-free assumption of NLFFF models. The procedure for removing the forces and noises in observed data is called preprocessing. In this paper, we extend the preprocessing code of Jiang ＆ Feng to spherical coordinates for a full sphere. We first smooth the observed data with Gaussian smoothing, and then split the smoothed magnetic field into a potential field and a non-potential field. The potential part is computed by a numerical potential field model, and the non-potential part is prepro- cessed using an optimization method to minimize the magnetic forces and magnetic torques. Applying the code to synoptic charts of the vector magnetic field from SDO/HMI, we find it can effectively reduce the noises and forces, and improve the quality of data for a better input which will be used for NLFFF extrapolations applied to the global corona.

关键词： magnetic fields - magnetohydrodynamics (MHD) - methods numerical - Sun corona