检索结果-南通市图书馆

Multi-timescale feature extraction method of wastewater treatment process based on adaptive entropy

维普期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

CHINESE JOURNAL OF CHEMICAL ENGINEERING 2024年第12期76卷 264-271页

作者： Han, Honggui Zhao, Yaqian Wu, Xiaolong yang, hongyan Beijing Univ Technol Sch Informat Sci & Technol Beijing 100124 Peoples R China Beijing Univ Technol Coll Environm Sci & Engn Beijing 100124 Peoples R China Beijing Key Lab Computat Intelligence & Intelligen Beijing 100124 Peoples R China Minist Educ Engn Res Ctr Digital Community Beijing 100124 Peoples R China

In wastewater treatment systems, extracting meaningful features from process data is essential for effective monitoring and control. However, the multi-time scale data generated by different sampling frequencies pose a challenge to accurately extract features. To solve this issue, a multi-timescale feature extraction method based on adaptive entropy is proposed. Firstly, the expert knowledge graph is constructed by analyzing the characteristics of wastewater components and water quality data, which can illustrate various water quality parameters and the network of relationships among them. Secondly, multiscale entropy analysis is used to investigate the inherent multi-timescale patterns of water quality data in depth, which enables us to minimize information loss while uniformly optimizing the timescale. Thirdly, we harness partial least squares for feature extraction, resulting in an enhanced representation of sample data and the iterative enhancement of our expert knowledge graph. The experimental results show that the multi-timescale feature extraction algorithm can enhance the representation of water quality data and improve monitoring capabilities. (c) 2024 The Chemical Industry and Engineering Society of China, and Chemical Industry Press Co., Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.

关键词： Feature extraction Knowledge graph Wastewater treatment process Adaptive entropy

Mobile phone recognition method based on bilinear convolutional neural network

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Technological Sciences) 2021年第11期64卷 2477-2484页

作者： HAN HongGui ZHEN Qi yang hongyan DU YongPing QIAO JunFei Faculty of Information Technology Beijing University of TechnologyBeijing 100124China

Model recognition of second-hand mobile phones has been considered as an essential process to improve the efficiency of phone recycling. However, due to the diversity of mobile phone appearances, it is difficult to realize accurate recognition. To solve this problem, a mobile phone recognition method based on bilinear-convolutional neural network(B-CNN) is proposed in this ***, a feature extraction model, based on B-CNN, is designed to adaptively extract local features from the images of secondhand mobile phones. Second, a joint loss function, constructed by center distance and softmax, is developed to reduce the interclass feature distance during the training process. Third, a parameter downscaling method, derived from the kernel discriminant analysis algorithm, is introduced to eliminate redundant features in B-CNN. Finally, the experimental results demonstrate that the B-CNN method can achieve higher accuracy than some existing methods.

关键词： bilinear convolutional neural network low-rank decomposition joint loss fine-grained image recognition

Subspace Identification for Closed-Loop Systems With Unknown Deterministic Disturbances

在线全文

学校读者我要写书评

暂无评论

IEEE/CAA Journal of Automatica Sinica 2023年第12期10卷 2248-2257页

作者： Kuan Li Hao Luo Yuchen Jiang Dejia Tang hongyan yang IEEE Shanghai Aerospace Control Technology Institute Shanghai 201109China the Control and Simulation Center School of AstronauticsHarbin Institute of TechnologyHarbin 150006China the Faculty of Information Technology Engineering Research Center of Digital CommunityMinistry of EducationBeijing University of TechnologyBeijing 100124China

This paper presents a subspace identification method for closed-loop systems with unknown deterministic *** deal with the unknown deterministic disturbances,two strategies are implemented to construct the row space that can be used to approximately represent the unknown deterministic disturbances using the trigonometric functions or Bernstein polynomials depending on whether the disturbance frequencies are *** closed-loop identification,CCF-N4SID is extended to the case with unknown deterministic disturbances using the oblique *** addition,a proper Bernstein polynomial order can be determined using the Akaike information criterion(AIC)or the Bayesian information criterion(BIC).Numerical simulation results demonstrate the effectiveness of the proposed identification method for both periodic and aperiodic deterministic disturbances.

关键词： Bernstein polynomial closed-loop system subspace identification unknown deterministic disturbances

Production of radicals in the ozonolysis of propene in air

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2009年第3期52卷 356-361页

作者： QI Bin yang Bing WANG ZhuQing yang hongyan LIU Lu School of Chemistry and Material Sciences Shaanxi Normal UniversityXi’an 710062China

Radical production in the ozonolysis of propene in air was monitored directly by a peroxy radical chemical amplification (PERCA) instrument at room temperature (298±2 K) and atmospheric pressure (1×105 Pa). The ozonolysis reactions were conducted in a flow tube under pseudo-first-order conditions for ozone. The decay in ozone was calculated based on reaction time tr and effective rate constant keff (keff = k1[C3H6]0)) for the ozone-propene reaction. The total radical yields relative to consumed ozone were determined to be 0.97±0.17 (σ). A box model was used to simulate radical production in the ozone-propene reaction. The model-derived radical yields agree well with those from experiment within the uncertainty of the two methods. In addition, the yields for OH, HO2 and CH3O2 were obtained from the measured total radical yields and radical partitioning derived from the box model. The yield is 0.39±0.08 (σ) for OH, 0.19±0.04 (σ) for HO2, and 0.39±0.08 (σ) for CH3O2. This work suggests that the previously measured radical yield by indirect method for the ozonolysis of propene may be underes-timated.

关键词： yield radical ozonolysis propene PERCA

Theoretical Study of the Effect of Multi-Diameter Distribution on the Mie Scattering Characteristics of Milk Fat

在线全文

学校读者我要写书评

暂无评论

Journal of Harbin Institute of Technology(New Series) 2015年第6期22卷 115-120页

作者： Jinying Yin Siqi Zhang hongyan yang Zhen Zhou School of Measurement and Communication Harbin University of Science & Technology

To correct the light scattering property parameters of milk fat for improving the detection accuracy,the Mie-theory was used to establish a predictive model for light scattering properties of milk fat globule with multi-diameter distributions, by means of Monte Carlo approach to simulate actual multi-diameter size distribution of milk fat globule in milk fat solution. Scattering coefficient and absorption coefficient of multidiameter distribution milk fat particles were calculated by simulating the particles size distribution in milk fat solution. And the light scattering properties of multi-diameter distribution was compared with that of volume mean diameter,Sauter mean diameter and numerical mean diameter in milk fat solution. Theoretical simulation results indicate that the scattering coefficient and absorption coefficient of milk fat particles are determined by the particle size distribution in milk fat solution. There is a distinct difference in scattering characteristics between the milk fat particles with multi-diameter distribution and that with mean diameters. Compared to that with multi-diameter distribution,the scattering coefficient of the milk fat particles with mean diameter has a maximum mean deviation of 9042 m-1. The particle size distribution is not completely determined by the mean diameters. The dependence of the light scattering properties on the particle size distribution should be considered into the model and simulation. Therefore,it is found that the particle size distribution in milk fat solution is an essential and critical factor to significantly improve the detection accuracy of milk fat content.

关键词： light scattering particle size distribution mie-theory milk fat globule

Towards IoT-based sustainable digital communities

在线全文

学校读者我要写书评

暂无评论

Intelligent and Converged Networks 2022年第2期3卷 190-203页

作者： Fangyu Li hongyan yang Xuejin Gao Honggui Han Faculty of Information Technology Beijing Key Laboratory of Computational Intelligence and Intelligent SystemEngineering Research Center of Digital CommunityMinistry of Educationand Beijing Artificial Intelligence InstituteBeijing University of TechnologyBeijing 100124China

Seeking continuous development,a modern community must also be able to adapt to future possible challenges using constrained or limited *** a revolutionary communication paradigm,the Internet of Things(IoT)empowers the cutting-edge and emerging applications which enable manifold new intelligent services towards a smart *** sophisticated ecosystem of a digital community is made feasible by the IoT infrastructure,which also provides community control with access to a wealth of actual *** addition,IoT platforms empower the ubiquitous computing ability,providing more potentials to the actuators in perception layer in the IoT *** more and more population in the urban areas,sustainability issues have become a key factor to consider in the development of a digital *** give a modern survey in this study on the most recent developments in IoT for sustainable digital *** carefully examining the most recent literature,we specifically highlight the various smart digital community application scenarios,such as smart buildings,energy management,green transportation,trash management,*** also look into a number of major issues facing the use of IoT technology in digital ***,we discuss potential future applications and future research areas for IoT,the critical component of sustainable digital communities.

关键词： Internet of Things digital communities sustainability smart systems

Water effect on peroxy radical measurement by chemical amplification: Experimental determination and chemical mechanism

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China Chemistry 2008年第3期51卷 282-288页

作者： QI Bin LIU Lu CHAO YuTao WANG ZhuQing yang hongyan School of Chemistry and Material Sciences Shaanxi Normal UniversityXi’an 710062China

The water effect on peroxy radical measurement by chemical amplification was determined experimentally for HO2 and HO2+OH, respectively at room temperature (298±2) K and atmospheric pressure (1×105 Pa). No significant difference in water effect was observed with the type of radicals. A theoretical study of the reaction of HO2·H2O adduct with NO was performed using density functional theory at CCSD(T)/6-311 G(2d, 2p)//B3LYP/6-311 G(2d, 2p) level of theory. It was found that the primary reaction channel for the reaction is HO2·H2O+NO→HNO3+H2O (R4a). On the basis of the theoretical study, the rate constant for (R4a) was calculated using Polyrate Version 8.02 program. The fitted Arrenhnius equation for (R4a) is k = 5.49×107 T 1.03exp(?14798/T) between 200 and 2000 K. A chemical model incorporated with (R4a) was used to simulate the water effect. The water effect curve obtained by the model is in accordance with that of the experiment, suggesting that the water effect is probably caused mainly by (R4a).

关键词： peroxy radical chemical amplification water effect model density functional theory

Degradation of corn stalk by the composite microbial system of MC1

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2008年第1期20卷 109-114页

作者： GUO Peng WANG Xiaofen ZHU Wanbin yang hongyan CHENG Xu CUI Zongjun College of Agronomy and Biotechnology China Agricultural University Key Laboratory of Crop Cultivation and Farming System Ministry of Agriculture of China Belting 100094 China Center of Biomass Engineering China Agricultural University Beifing 100094 China

The composite microbial system of MC1 was used to degrade corn stalk in order to determine properties of the degraded products as well as bacterial composition of MC1. Results indicated that the pH of the fermentation broth was typical of lignocellulose degradation by MC1, decreasing in the early phase and increasing in later stages of the degradation. The microbial biomass peaked on the day 3 after degradation. The MC1 efficiently degraded the corn stalk by nearly 70% during which its cellulose content decreased by 71.2%, hemicellulose by 76.5% and lignin by 24.6%. The content of water-soluble carbohydrates （WSC） in the fermentation broth increased progressively during the first three days, and decreased thereafter, suggesting an accumulation of WSC in the early phase of the degradation process. Total levels of various volatile products peaked in the third day after degradation, and 7 types of volatile products were detected in the fermentation broth. These were ethanol, acetic acid, 1,2-ethanediol, propanoic acid, butanoic acid, 3- methyl-butanoic acid and glycerine. Six major compounds were quantitatively analysed and the contents of each compound were ethanol （0.584 g/L）, acetic acid （0.735 g/L）, 1,2-ethanediol （0.772 g/L）, propanoic acid （0.026 g/L）, butanoic acid （0.018 g/L） and glycerine （4.203 g/L）. Characterization of bacterial cells collected from the culture solution, based on 16S rDNA PCR-DGGE analysis of DNAs, showed that the composition of bacterial community in MC1 coincided basically with observations from previous studies. This indicated that the structure of MC1 is very stable during degradation of different lignocellulose materials.

关键词： corn stalk cellulose degradation composite microbial system MC1

Modeling of Refractive Index Sensing Using Au Aperture Arrays on a Bragg Fiber Facet

在线全文

学校读者我要写书评

暂无评论

Photonic Sensors 2019年第4期9卷 337-343页

作者： Gongli XIAO hongyan yang Guangxi Key Laboratory of Precision Navigation Technology and Application Guilin University of Electronic TechnologyGuilin 541004China School of Electronic Engineering and Automation Guilin University of Electronic TechnologyGuilin 541004China

A finite-difference-time-domain(FDTD)approach is undertaken to investigate the extraordinary optical transmission(EOT)phenomenon of Au circular aperture arrays deposited on a Bragg fiber facet for refractive index(RI)*** shows that the choice of effective indices and modal loss of the Bragg fiber core modes will affect the sensitivity enhancement by using a mode analysis *** critical parameters of Bragg fiber including the middle dielectric RI,as well as its gap between dielectric layers,which affect the EOT and RI sensitivity for the sensor,are discussed and *** is demonstrated that a better sensitivity of 156±5 nm per refractive index unit(RIU)and an averaged figure of merit exceeding 3.5 RIU‒1 are achieved when RI is 1.5 and gap is 0.02μm in this structure.

关键词： Optical fiber sensors surface plasmon resonance periodic array refractive index sensing finite-difference time-domain