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Automatic modeling algorithm of stochastic error for inertial sensors

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Control Theory and Technology 2024年第1期22卷 81-91页

作者： Luodi Zhao Long Zhao School of Automation Science and Electrical Engineering Beihang UniversityBeijing100191China Digital Navigation Center Beihang UniversityBeijing100191China Science and Technology on Aircraft Control Laboratory Beihang UniversityBeijing100191China

This paper proposes an automatic algorithm to determine the properties of stochastic processes and their parameters for inertial error. The proposed approach is based on a recently developed method called the generalized method of wavelet moments (GMWM), whose estimator was proven to be consistent and asymptotically normally distributed. This algorithm is suitable mainly (but not only) for the combination of several stochastic processes, where the model identification and parameter estimation are quite difficult for the traditional methods, such as the Allan variance and the power spectral density analysis. This algorithm further explores the complete stochastic error models and the candidate model ranking criterion to realize automatic model identification and determination. The best model is selected by making the trade-off between the model accuracy and the model complexity. The validation of this approach is verified by practical examples of model selection for MEMS-IMUs (micro-electro-mechanical system inertial measurement units) in varying dynamic conditions.

关键词： GMWM Stochastic process Inertial sensor Sensor calibration Error model Allan variance

Decreasing ruminal methane production through enhancing the sulfate reduction pathway

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Animal Nutrition 2022年第2期9卷 320-326页

作者： Yuchao Zhao Guangyong Zhao State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural University100193 BeijingChina

Methane(CH4)production from ruminants accounts for 16%of the global greenhouse gas emissions and represents 2%to 12%of feed energy.Mitigating CH_(4) production from ruminants is of great importance for sustainable development of the ruminant industry.H_(2) is the primary substrate for CH_(4) production in the processes of ruminal methanogenesis.Sulfate reducing bacteria are able to compete with methanogens for H_(2) in the rumen,and consequently inhibit the methanogenesis.Enhancing the ruminal sulfate reducing pathway is an important approach to mitigate CH_(4) emissions in ruminants.The review summarized the effects of sulfate and elemental S on ruminal methanogenesis,and clarified the related mechanisms through the impacts of sulfate and elemental S on major ruminal sulfate reducing bacteria.Enhancing the activities of the major ruminal sulfate reducing bacteria including Desulfovibrio,Desulfohalobium and Sulfolobus through dietary sulfate addition,elemental S and dried distillers grains with solubles can effectively decrease the ruminal CH_(4) emissions.Suitable levels of dietary addition with different S sources for reducing the ruminal CH_(4) production,as well as maintaining the performance and health of ruminants,need to be investigated in the future.

关键词： Methane Rumen Sulfur Sulfate reduction pathway

China's 'sky eye':exploring the universe by measuring faint cosmic radio signals

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National Science Review 2023年第7期10卷 261-263页

作者： Weijie Zhao NSR

The Five-Hundred-Meter Aperture Spherical Radio Telescope(FAST) is the worlds largest and most sensitive filled-aperture single-dish radio telescope,with a dish diameter of 500 meters and an effective illuminated diameter of 300 meters.This’big eye looking into the sky’is located in a natural karst rock basin in Guizhou Province in China,where the human-related radio background is rather low,so it can better listen to radio signals coming from outer space.The construction of the FAST began in 2011,and the first light was observed in 2016.In 2021,it was omcially opened to the global scientific community.According to FAST Chief Scientist Prof.Di Li of the National Astronomical Observatories (NAO) of the Chinese Academy of Sciences(CAS),～400 projects have been approved and io%of the total observing time now goes to international scientists.

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Inspired, but not mimicking: a conversation between artificial intelligence and human intelligence

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National Science Review 2022年第6期9卷 200-205页

作者： Weijie Zhao NSR

How intelligent is artificial intelligence(AI)? How intelligent will it become in the future? What is the relationship between AI and human intelligence(HI)? These questions have been a hot topic of discussion in recent years, but no consensus has yet been reached. To discuss these issues, we should first understand the concept of intelligence as well as the underlying mechanisms for both HI and AI. In this NSR Forum, experts from both disciplines gathered to discuss these issues; in particular, the similarities and differences between AI and HI, how these two disciplines could benefitfrom each other, and the emerging social and ethical challenges of AI.

关键词： Software engineering

Knowledge, attitude, and practice toward disease prevention among a high-risk population for chronic obstructive pulmonary disease: A cross-sectional study

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International Journal of Nursing Sciences 2023年第2期10卷 238-244页

作者： Lulu Zhao Qinghua Zhao Department of Nursing The First Affiliated Hospital of Chongqing Medical UniversityChongqingChina Department of Nursing The People’s Hospital of DazuChongqingChina

Objective This study aimed to describe the current situation of knowledge,attitude,and practice(KAP)of chronic obstructive pulmonary disease(COPD)prevention among a high-risk population for COPD.Methods A cross-sectional survey was conducted.A total of 241 participants at risk of COPD were selected who visited the respiratory outpatient department of a Class A tertiary hospital in Chongqing,China from January to December 2021.A self-developed COPD prevention KAP assessment was used for evaluation which included knowledge(21 items),attitude(9 items),and practice(9 items)three dimension,39 items.Results The average overall KAP score was 68.29±12.91,with scores for the knowledge,attitude,and practice dimension was 68.75±18.07,71.13±15.09 and 65.00±20.93,respectively.Among the people at risk of COPD,76.8%experienced a moderate level of KAP toward COPD prevention,while 22.0%were at a poor level.Significant differences in the KAP scores were based on gender,educational level,occupation,type of medical insurance,smoking,and passive smoking status(P<0.05).The male COPD high-risk group has better KAP toward COPD prevention than the female group(P<0.05).The knowledge and attitude of COPD prevention present worse in people with a high risk of COPD aged 70 or above,primary school and below educational level,and farmers(P<0.05).Smoking and passive smoking groups have higher recognition of the knowledge but the lower practice of COPD prevention(P<0.05).Conclusion The participants with a high risk of COPD had a moderate level of KAP for COPD prevention,in which the understanding and action on vaccination and lung function test was weak,but an active attitude for health.It is necessary to implement tailored health education interventions to their characteristics to reduce the incidence and development of COPD.

关键词： Chronic obstructive pulmonary disease Risk Knowledge Attitudes Practice

Comparative lifecycle greenhouse gas emissions and their reduction potential for typical petrochemical enterprises in China

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Journal of Environmental Sciences 2022年第6期34卷 125-138页

作者： Shujie Zhao Dongfeng Zhao Qingbin Song College of Chemical Engineering China University of Petroleum(East China)Qingdao 266580China Macao Environmental Research Institute Macao University of Science and TechnologyMacao 999078China

Petrochemical enterprises have become a major source of global greenhouse gas(GHG)emissions.Yet,due to the unavailability of basic data,there is still a lack of case studies to quantify GHG emissions and provide petrochemical enterprises with guidelines for implementing energy conservation and emission reduction strategies.Therefore,this study conducted a life cycle assessment(LCA)analysis to estimate the GHG emissions of four typical petrochemical enterprises in China,using first-hand data,to determine possible emission reduction measures.The analytical data revealed that Dushanzi Petrochemical(DSP)has the highest GHG emission intensity(1.17 tons CO_(2)e/ton),followed by Urumqi Petrochemical(UP)(1.08 tons CO_(2)e/ton),Dalian Petrochemical(DLP)(average 0.58 tons CO_(2)e/ton)and Karamay Petrochemical(KP)(average 0.50 tons CO_(2)e/ton)over the whole life cycle.At the same time,GHG emissions during fossil fuel combustion were the largest contributor to the whole life cycle,accounting for about 77.31%–94.27% of the total emissions.In the fossil-fuel combustion phase,DSP had the highest unit GHG emissions(1.20 tons CO_(2)e),followed by UP(0.89 tons CO_(2)e).In the industrial production phase,DLP had the highest unit GHG emissions(average 0.13 tons CO_(2)e/ton),followed by UP(0.10 tons CO_(2)e/ton).During the torch burning phase,torch burning under accident conditions was the main source of GHG emissions.It is worth noting that the CO_(2) recovery stage has"negative value,"indicating that it will bring some environmental benefits.Further scenario analysis shows that effective policies and advanced technologies can further reduce GHG emissions.

关键词： Greenhouse gas(GHG)emissions Petrochemical enterprises Life cycle assessment Scenario analysis Reduction opportunities

Ling-Ling Chen: RNA has its own features;don't study it as a protein

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National Science Review 2024年第2期11卷 301-305页

作者： Weijie Zhao NSR

Non-coding RNA(ncRNA) has been a very active research area over the past 30 years. From small nc RNA – the discovery of RNA interference won the lead researchers the Nobel Prize, to long ncRNA(lncRNA), which has attracted much attention in recent years, various nc RNAs participate in all kinds of biological processes and show a variety of biomedical application prospects.

关键词： RNA

Honor classes in China's higher education:perspectives from four universities

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National Science Review 2022年第3期9卷 169-174页

作者： Weijie Zhao NSR

Ever since the University of Science and Technology of China started the Special Class for the Gi?ted Young in 1978, many Chinese universities have set up their own honor classes under different names such as Gi?ted Young Class, Basic Science Class, Experimental Class or Elite Class.These are o?ten small classes; some emphasize mathematics and physics, aiming to cultivate talents with broad basic knowledge, while others focus on a particular discipline, such as computer science. In 2011, the Chinese Ministry of Education started the Experimental Program for the Cultivation of Top Talents in Basic Sciences, which boosted a new round of honor classes.

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Reconfigurable intelligent surfaces for 6G:applications,challenges,and solutions

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Frontiers of Information Technology & Electronic Engineering 2023年第12期24卷 1669-1688页

作者： Yajun Zhao Beijing Institute of Technology Beijing100081China ZTE Corporation Beijing100029China

Scholars are expected to continue enhancing the depth and breadth of theoretical research on reconfigurable intelligent surface(RIS)to provide a higher theoretical limit for RIS engineering applications.Notably,significant advancements have been achieved through both academic research breakthroughs and the promotion of engineering applications and industrialization.We provide an overview of RIS engineering applications,focusing primarily on their typical features,classifications,and deployment scenarios.Furthermore,we systematically and comprehensively analyze the challenges faced by RIS and propose potential solutions including addressing the beamforming issues through cascade channel decoupling,tackling the effects and resolutions of regulatory constraints on RIS,exploring the network-controlled mode for RIS system architecture,examining integrated channel regulation and information modulation,and investigating the use of the true time delay(TTD)mechanism for RIS.In addition,two key technical points,RIS-assisted non-orthogonal multiple access(NOMA)and RIS-based transmitter,are reviewed from the perspective of completeness.Finally,we discuss future trends and challenges in this field.

关键词： 6G Reconfigurable intelligent surface(RIS) Cascade channel decoupling RIS regulatory constraint RIS system