检索结果-南通市图书馆

Scale-Invariant Occupancy of Phase Space and Additivity of Nonextensive Entropy S_q

在线全文

学校读者我要写书评

暂无评论

Journal of Shanghai Jiaotong university(Science) 2010年第4期15卷 441-446页

作者：赵伟伞冶 control and simulation center Harbin Institute of Technology

Phase space can be constructed for N equal and distinguishable binary subsystems which are correlated in a scale-invariant manner.In the paper,correlation coefficient and reduced probability are introduced to characterize the scale-invariant correlated binary subsystems.Probabilistic sets for the correlated binary subsys-tems satisfy Leibnitz triangle rule in the sense that the marginal probabilities of N-system are equal to the joint probabilities of the(N-1)-system.For entropic index q=1,nonextensive entropy Sq is shown to be additive in the scale-invariant occupation of phase space.

关键词： nonextensive entropy additivity correlation scale-invariance

A Hierarchical LSTM-Based Vehicle Trajectory Prediction Method Considering Interaction Information

在线全文

学校读者我要写书评

暂无评论

Automotive Innovation 2024年第1期7卷 71-81页

作者： Haitao Min Xiaoyong Xiong Pengyu Wang Zhaopu Zhang State Key Laboratory of Automotive simulation and control Jilin UniversityChangchun 130012China

Trajectory prediction is an essential component in autonomous driving systems,as it can forecast the future movements of surrounding vehicles,thereby enhancing the decision-making and planning capabilities of autonomous driving systems.Traditional models relying on constant acceleration and constant velocity often experience a reduction in prediction accu-racy as the forecasted timeframe extends.This limitation makes it challenging to meet the demands for medium to long-term trajectory prediction.Conversely,data-driven models,particularly those based on Long Short-Term Memory(LSTM)neural networks,have demonstrated superior performance in medium to long-term trajectory prediction.Therefore,this study introduces a hierarchical LSTM-based method for vehicle trajectory prediction.Considering the difficulty of using a single LSTM model to predict trajectories for all driving intentions,the trajectory prediction task is decomposed into three sequential steps:driving intention prediction,lane change time prediction,and trajectory prediction.Furthermore,given that the driving intent and trajectory of a vehicle are always subject to the influence of the surrounding traffic flow,the predictive model proposed in this paper incorporates the interactional information of neighboring vehicle movements into the model input.The proposed method is trained and validated on the real vehicle trajectory dataset Next Generation simulation.The results show that the proposed hierarchical LSTM method has a lower prediction error compared to the integral LSTM model.

关键词： Autonomous vehicles Trajectory prediction Long Short-Term Memory Driving intention prediction

Human-Machine Shared Lateral control Strategy for Intelligent Vehicles Based on Human Driver Risk Perception Reliability

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Automotive Innovation 2024年第1期7卷 102-120页

作者： Dongjian Song Bing Zhu Jian Zhao Jiayi Han State Key Laboratory of Automotive simulation and control Jilin UniversityChangchun 130022China

Intelligent vehicle(Ⅳ)technology has developed rapidly in recent years.However,achieving fully unmanned driving still presents numerous challenges,which means that human drivers will continue to play a vital role in vehicle operation for the foreseeable future.Human-machine shared driving,involving cooperation between a human driver and an automated driving system(AVS),has been widely regarded as a necessary stage for the development of IVs.Focusing onⅣdriving safety,this study proposed a human-machine shared lateral control strategy(HSLCS)based on the reliability of driver risk perception.The HSLCS starts by identifying the effective areas of driver risk perception based on eye movements.It establishes an anisotropic driving risk field,which serves as the foundation for the AVS to assess risk levels.Building upon the cumulative and diminishing effects of risk perception,the proposed approach leverages the driver's risk perception effective area and converts the risk field into a representation aligned with the driver's perspective.Subsequently,it quantifies the reliability of the driver's risk perception by using area-matching rules.Finally,based on the driver’s risk perception reliability and dif-ferences in lateral driving operation between the human driver and the AVS,the dynamic distribution of driving authority is achieved through a fuzzy rule-based system,and the human-machine shared lateral control is completed by using model predictive control.The HSLCS was tested across various scenarios on a driver-in-the-loop test platform.The results show that the HSLCS can realize the synergy and complementarity of human and machine intelligence,effectively ensuring the safety ofⅣoperation.

关键词： Intelligent vehicle Human-machine shared driving Risk perception Driving authority distribution

Temporal and Spatial Trends in HIV Positivity Rate for VCT Clinics—China,2015–2022

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

China CDC weekly 2024年第1期6卷 6-11页

作者： Yi Liu Rong Su Dongmin Li Shaorong Wang Mengjie Han National center for AIDS/STD control and Prevention Chinese Center for Disease Control and PreventionBeijingChina

Introduction:Human immunodeficiency virus(HIV)voluntary counseling and testing(VCT)clinics play a critical role in identifying and diagnosing HIV cases.This study aimed to describe the trend of HIV positivity rate(HPR)among Chinese VCT clinics between 2015 and 2022.Methods:This study utilized data from the China Information System for Disease control and Prevention to analyze the trend in the HPR for VCT clinics from 2015 to 2022.The HPR was calculated by dividing the number of newly-reported HIV cases by the number of HIV tests,multiplied by 100%.To identify temporal and spatial trends in the HPR,we employed joinpoint regression analysis and the Getis-Ord hotspot analysis.Results:From 2015 to 2022,VCT clinics in China performed a total of 22,075,386 HIV tests,leading to the identification of 260,353 HIV cases,resulting in a HPR of 1.18%.The HPR consistently declined over the study period,with an average annual percent change(AAPC)of−7.5%(95%confidence interval:−12.6%,−2.2%,P<0.05).The number of HPR hotspots also decreased from 41 in 2015 to 23 in 2022.These HPR hotspots were primarily located in Yunnan,Sichuan,Guangdong,and Guangxi provincial-level administrative divisions(PLADs).Among the 31 PLADs,16 showed a significant decrease in HPR during the study period(AAPC<0,PAAPC<0.05).Conclusions:VCT clinics in China have played a significant role in identifying HIV cases.The declining HPR observed in these clinics may indicates the progress has been made in some degree in mitigating HIV among high-risk populations.Therefore,it is crucial to further improving the utilization of VCT clinics for HIV testing.

关键词： VCT dividing Spatial

The risk factors and threshold level of subchronic inhalation exposure of reclaimed water

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第3期137卷 639-650页

作者： Jiayang Kong Yun Lu Yunru Ren Menghao Chen Gang Liu Liangliang Shi State Key Joint Laboratory of Environment simulation and Pollution control State Environment Protection Key Laboratory of Microorganism Application and Risk ControlSchool of EnvironmentTsinghua UniversityBeijing 100084China

Inhalation of reclaimed water is known to cause lung infammation,and free endotoxins have been shown to be a major risk factor for acute exposure.Subchronic exposure has also been shown to induce infammatory responses with visible tissue damage.However,subchronic risk factors have yet to be identified,and a threshold for the protection of occupational populations during urban reuse is necessary.In this study,potential risk factors in reclaimed water were examined by subchronic exposure with fractionated reclaimed water,and the health risk threshold was tested with a series of diluted reclaimed water.Accordingly,following a 12-week exposure,macromolecules and microorganisms were found to be two major risk factors in reclaimed water that could cause pulmonary infammation,including increased proportion of polymorphonuclear leukocytes in bronchoalveolar fuid,formation of inducible bronchus-associated lymphoid tissue,and elevation of Immunoglobulin A levels.Moreover,infammation persisted after a 4-week recovery period.The calculated threshold of reclaimed water exposure for mice was 31.8 Endotoxin Unit(EU)/(kg·day)under when exposed to 50%additional relative humidity from reclaimed water at 25℃ for 2 hr/day.Meanwhile,the subchronic threshold estimate for humans under the same exposure conditions was found to be 12.2 EU/(kg·day),corresponding to endotoxin levels of 61.7 EU/mL in reclaimed water.The threshold level of endotoxin was lower than that in most non-potable reclaimed water.The findings of this study suggest that occupational exposure of reclaimed water can serve as a potential risk to workers.

关键词： Reclaimed water Inhalation exposure Risk factor Threshold Infammation Endotoxin

A reduced combustion mechanism of ammonia/diesel optimized with multi-objective genetic algorithm

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第4期34卷 187-200页

作者： Wanchen Sun Shaodian Lin Hao Zhang Liang Guo Wenpeng Zeng Genan Zhu Mengqi Jiang State Key Laboratory of Automotive simulation and control Jilin UniversityChangchun 130025China

For the deep understanding on combustion of ammonia/diesel,this study develops a reduced mechanism of ammonia/diesel with 227 species and 937 reactions.The sub-mechanism on ammonia/interactions of N-based and C-based species(N—C)/NOx is optimized using the Non-dominated Sorting Genetic Algorithm II(NSGA-II)with 200 generations.The optimized mechanism(named as 937b)is validated against combustion characteristics of ammonia/methane(which is used to examine the accuracy of N—C interactions)and ammonia/diesel blends.The ignition delay times(IDTs),the laminar flame speeds and most of key intermediate species during the combustion of ammonia/methane blends can be accurately simulated by 937b under a wide range of conditions.As for ammonia/diesel blends with various diesel energy fractions,reasonable predictions on the IDTs under pressures from 1.0 MPa to5.0 MPa as well as the laminar flame speeds are also achieved by 937b.In particular,with regard to the IDT simulations of ammonia/diesel blends,937b makes progress in both aspects of overall accuracy and computational efficiency,compared to a detailed ammonia/diesel mechanism.Further kinetic analysis reveals that the reaction pathway of ammonia during the combustion of ammonia/diesel blend mainly differs in the tendencies of oxygen additions to NH_2 and NH with different equivalence ratios.

关键词： Ammonia Diesel Combustion Kinetic mechanism Multi-objective optimization

维普期刊数据库博看期刊

Kinematics analysis of a novel all-attitude flight simulator

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2010年第2期53卷 236-247页

作者： WANG XiaoChen , ZHAO Hui, MA KeMao, HUO Xin & YAO Yu control and simulation center, Harbin Institute of Technology, Harbin 150080, China control and simulation center Harbin Institute of Technology Harbin China

To overcome the kinematic singularity limitation of simulator, which is unavoidable in a three-axis architecture, an all-attitude flight simulator in a four-axis architecture is proposed. The simulator can always provide 3DOF motion by applying redundant manipulator mechanism. For direct kinematics of the manipulator, a dual-Euler method is adopted to solve the expressions of attitude angles; thus computation singularity of all- attitude angles is overcome. For inverse kinematics of the manipulator, pseudo-inverse gradient projection method is used to obtain optimal velocity solution. Then, based on dynamic control method, optimal position solution is obtained. The proposed inverse kinematics algorithm can achieve desired attitudes, as well as can avoid kinematics singularity and axis angle limits. The simulation results show that the kinematic performance of the four-axis all-attitude flight simulator is superior to that of a three-axis simulator.

关键词： all-attitude flight simulator kinematic singularity direct kinematics inverse kinematics

Prevalence and serotype distribution of nasopharyngeal carriage of Streptococcus pneumoniae among healthy children under 5 years of age in Hainan Province, China

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Infectious Diseases of Poverty 2024年第1期13卷 42-52页

作者： Jian Wang Li Qiu Shuang Bai Wei Zhao Ao Zhang Jing Li Jun-Nan Zhang Shan-Shan Zhou Ren Qiu Zhu Huang Jv-Xia Liu Ting-Bin Wang Xue Sun Jiang Wu Qun Zheng Bin He Min Lv Beijing center for Disease Prevention and control BeijingChina Beijing Research center for Respiratory Infectious Diseases BeijingChina Hainan Provincial center for Disease control and Prevention HaikouChina Haikou center for Disease control and Prevention HaikouHainanChina Wanning center for Disease control and Prevention WanningHainanChina Baisha County center for Disease control and Prevention BaishaHainanChina Qiongzhong County center for Disease control and Prevention QiongzhongHainanChina

Background The thirteen-valent pneumococcal conjugate vaccine(PCV13)is not included in the national immu-nization program and is administered voluntarily with informed consent in China.In preparation for assessing the impact of pilot introduction in Hainan Province,we conducted a carriage study among children under 5 years of age from four locations in Hainan Province,China.Methods From March to June 2022,nasopharyngeal(NP)swabs,collected from healthy children aged younger than 59 months who lived in the 4 different locations(Haikou,Wanning,Baisha and Qiongzhong)in Hainan Province,were tested for pneumococcus using conventional culture.Pneumococcal isolates were serotyped using the Quel-lung reaction.Risk factors associated with pneumococcal colonization were assessed using univariate analysis and multivariable logistic regression adjusting for age,daycare attendance and other factors.Results Pneumococcus was isolated in 710(30.4%)of the 2333 children enrolled.Of 737 pneumococci,29 serotypes were identifed;60.9%were PCV13 serotypes;the most common vaccine serotypes were 6B(20.4%),19F(13.0%),6A(11.9%)and 23F(6.1%);and the most common nonvaccine serotypes were 23A(12.9%),34(6.1%)and nontypeable(NT)pneumococci(5.6%).Children vaccinated with PCV13 had lower carriage(17.7%vs 32.5%;P=0.0001)and fewer PCV13 serotypes(41.9%vs 62.7%;P=0.0017)compared to unimmunized children.After adjustment,NP carriage Was higher among children attending daycare(aOR=2.3,95%CI:1.7-3.2),living in rural areas(aOR=1.4,95%CI:1.1-1.8),living with siblings(aOR=1.3,95%CI:1.0-1.6)and whose mothers had completed senior high/technical sec-ondary school(aOR=1.5,95%CI:1.1-2.0).In contrast,completion of 3-4 doses of PCV13 were associated with a lower carriage rate(aOR=0.6,95%CI:0.4-0.9).Conclusions We established the baseline of pneumococcal carriage,serotype distribution and PCV13 immuni-zation rates among healthy children under 5 years of age in Hainan Province,prior to the introduction of PCV13 into the national immunization program.The high proport

关键词： Pneumococcus Nasopharyngeal carriage Serotypes distribution Children Hainan Province China

HIV Infection and Associated Factors Among Out-of-School MSM Aged 16–24 Years—6 Cities and Tianjin Municipality,China,2022–2023

在线全文

学校读者我要写书评

暂无评论

China CDC weekly 2024年第3期6卷 45-50页

作者： Hui Liu Qiyu Zhu Lei Zhang Yujing Liu Peng Xu Mengjie Han National center for AIDS/STD control and Prevention Chinese Center for Disease Control and PreventionBeijingChina Chinese Association of STD and AIDS Prevention and control BeijingChina Beijing Chaoyang Kangzhong Health and Education center BeijingChina

What is already known about this topic?Approximately 80%of newly diagnosed human immunodeficiency virus(HIV)cases among individuals aged 15–24 years in China are attributed to out-ofschool youth.What is added by this report?This study presents findings on HIV prevalence and comprehensive insights into HIV service utilization,risky behaviors,and prevention knowledge among young out-of-school men who have sex with men(MSM)aged 16–24 years in China.This population exhibits a disproportionately high burden of HIV,with only 51.6%of HIV cases previously diagnosed.What are the implications for public health practice?HIV services should be expanded to include these key populations.Tailored interventions are needed to remove barriers to regular HIV services faced by young key populations.

关键词： prevention remove expanded