检索结果-南通市图书馆

Pedestrian trajectory prediction in crossing scenario using fuzzy logic and switching Kalman filter

在线全文

学校读者我要写书评

暂无评论

The Journal of China Universities of Posts and Telecommunications 2018年第6期25卷 31-43页

作者： Wang Likun liu Lu yu Dameng Xu Qing Wang Jianqiang State Key Laboratory of Automotive Safety and Energy Tsinghua UniversityBeijing 100084China

Pedestrian trajectory prediction plays an important role in bothadvanced driving assistance system(ADAS) and autonomous vehicles. An algorithm for pedestrian trajectory prediction in crossing scenario is proposed. To obtain features of pedestrian motion, we develop a method for data labelling and pedestrian body orientation regression. Using the hierarchical features as domain of discourse, fuzzy logic rules are built to describe the transition between different pedestrian states and motion models. With derived probability of each type of motion model we further predict the pedestrian trajectory in the next 1.5 s using switching Kalman filter(KF). The proposed algorithm is further verified in our dataset, and the result indicates that the proposed algorithm successfully predicts pedestrian’s crossing behavior 0.4 s earlier before pedestrian moves. Meanwhile, the precision of predicted trajectory surpasses other methods including interacting multi-model KF and dynamic Bayesian network(DBN).

关键词： pedestrian protection trajectory prediction fuzzy logic switching KF

Neurogenic nitric oxide facilitates the central nociceptive transmission of migraine attacks

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2011年第3期6卷 213-218页

作者： Wang, Hebo Qi, Huijun yu, Shengyuan Yang, Sumian liu, Ruozhuo Hebei Gen Hosp Dept Neurol Shijiazhuang 050051 Hebei Peoples R China Hebei Gen Hosp Dept Emergency Shijiazhuang 050051 Hebei Peoples R China Chinese Peoples Liberat Army Gen Hosp Dept Neurol Beijing 100853 Peoples R China

Recent studies have shown that nitric oxide （NO） can induce migraine attacks at three possible sites of action： nitroxidergic nerves, the vascular endothelium, and the central nervous system. Most previous studies have focused on the former two sites of action. Several experiments using exogenic NO donors have suggested that nitroglycerin may induce migraine via central mechanisms. However, few studies have investigated the source of the NO involved in the central mechanisms of migraine. The present study used a cat model of migraine to represent migraine attacks in humans. We performed immunochemical staining of successive frozen sections of the brainstem and upper cervical spinal cord, and then used c-Fos protein expression to label nerve cell activation. We observed the effects of N^ω-nitro-L-arginine methyl ester （L-NAME）, a non-selective nitric oxide synthase （NOS） inhibitor, and 7-nitroindozole （7-NI）, a selective neuronal NOS inhibitor, on c-Fos and nNOS expression, which were induced by electrical stimulation to the dura mater near the superior sagittal sinus. The results demonstrated that c-Fos or nNOS immunoreactive cells was concentrated in the superficial layers （laminae Ⅰ and Ⅱ） of the spinal nucleus of trigeminal nerve. L-NAME and 7-NI pre-treatment significantly decreased c-Fos and neurogenic NOS expression; and there was a significant linear correlation between c-Fos and NOS expression （r = 0.858 2, P 〈 0.01）. These findings suggest that neurogenic NO could facilitate migraine nociceptive transmission to second-order neurons of the trigeminal nerve. However, L-NAME and 7-NI may block the activation of neurons in the spinal nucleus of the trigeminal nerve by inhibiting NO synthesis, and thereby attenuate acute migraine attacks.

关键词： migraine c-Fos nitric oxide dura mater neurogenic superior sagittal sinus

Statistics-based Optimization of the Polarimetric Radar Hydrometeor Classification Algorithm and Its Application for a Squall Line in South China

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2018年第3期35卷 296-316页

作者： Chong WU Liping liu Ming WEI Baozhu XI Minghui yu Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters Nanjing University of Information Science and Technology Nanjing 210044 China State Key Lab of Severe Weather Chinese Academy of Meteorological Science Beijing 100081 China

A modified hydrometeor classification algorithm （HCA） is developed in this study for Chinese polarimetric radars. This algorithm is based on the U.S. operational HCA. Meanwhile, the methodology of statistics-based optimization is proposed including calibration checking, datasets selection, membership functions modification, computation thresholds modification, and effect verification. Zhuhai radar, the first operational polarimetric radar in South China, applies these procedures. The systematic bias of calibration is corrected, the reliability of radar measurements deteriorates when the signal-to-noise ratio is low, and correlation coefficient within the melting layer is usually lower than that of the U.S. WSR-88D radar. Through modification based on statistical analysis of polarimetric variables, the localized HCA especially for Zhuhai is obtained, and it performs well over a one-month test through comparison with sounding and surface observations. The algorithm is then utilized for analysis of a squall line process on 11 May 2014 and is found to provide reasonable details with respect to horizontal and vertical structures, and the HCA results---especially in the mixed rain-hail region--can reflect the life cycle of the squall line. In addition, the kinematic and microphysical processes of cloud evolution and the differences between radar- detected hail and surface observations are also analyzed. The results of this study provide evidence for the improvement of this HCA developed specifically for China.

关键词： dual polarization radar hydrometeor classification fuzzy logic scheme

Characteristics of strong earthquake evolution around the eastern boundary faults of the Sichuan-yunnan rhombic block

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2011年第11期54卷 1716-1729页

作者： CHENG Jia liu Jie GAN WeiJun yu HuaiZhong LI Gang China Earthquake Network Center Beijing 100045 China State Key Laboratory of Earthquake Dynamics Institute of Geology China Earthquake Administration Beijing 100029 China

Based on the existing materials of fault segmentation,characteristic earthquakes,and their empirical relationships,we calculated the parameters of the fault segments,such as length,width,magnitudes of characteristic earthquakes,*** by GPS velocity field,the slip rates of these fault segments in depth were inversed using the 3-D half-space elastic dislocation *** not all of the recurrence periods and co-seismic displacements of characteristic earthquakes are known,we selected the fault segments with these two parameters known and calculated the accumulation rate of average co-seismic displacement,which shows the faults' slip rate in seismogenic ***,the slip rate in depth was compared with that in seismogenic layer,the relationship between them was obtained,and this relationship was used to get the recurrence periods and co-seismic displacements of all fault *** the studies above,we calculated the co-seismic deformation field of all the earthquakes larger than M s 6.8 from AD 1700 one by one and inversed the potential displacement in the co-seismic deformation ***,we divided the potential displacement by the slip rate from GPS inversion to get the influences of these fault segments,added the influences into the elapsed time of the characteristic earthquakes,and obtained the earthquake hazard degree of all the segments we studied in the form of the ratio of elapsed time to recurrence period;so,we name the ratio as the Impending Earthquake Risk (IER).Historical earthquake cases show that the fault segment is in safety when the IER is less than 1 but in danger after the IER becomes larger than *** 2009,the IER is larger than 1 on the following segments,1.35 on the Tagong segment of Xianshuihe fault,1 on the Menggu-Dongchuan segment,1.04 on the Dongchuan-Xundian segment,and 1.09 on the Yiliang-Chengjiang segment of Xiaojiang fault.

关键词： eastern boundary faults of Sichuan-yunnan rhombic block fault segment characteristic earthquake recurrence period earthquake Interaction Impending Earthquake Risk

Construction of CdSe/ZnS quantum dot microarray in a microfluidic chip

在线全文

学校读者我要写书评

暂无评论

Science China Chemistry 2012年第4期55卷 543-549页

作者： liu HongWei JING YingYing yu Xu PANG DaiWen ZHANG zhiLing Key Laboratory of Analytical Chemistry for Biology and Medicine(Ministry of Education) College of Chemistry and Molecular SciencesWuhan UniversityWuhan 430072China Institute of Biomedical and Health Engineering Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China

Microarray technology has been proved to be greatly helpful for biomedical and biological diagnosis. And the evaluation of its biological applications lies in the detection sensitivity, which requires high intensity and stability of the signal. Recently, several nanomaterials, especially semiconductor nanomaterials, due to their excellent fluorescence properties, have been widely used to construct microarrays for biosensors. Here, we presented an approach for constructing CdSe/ZnS quantum dot (QD) microarray in microfluidic channels on a glass slide by photolithography. The conditions for immobilizing stable and uniform QD microarray on the glass slide were optimized. Several types of QD microarrays with different emission wavelengths and modified groups were constructed using silanization and lithography technology. Based on the fluorescence quenching effect of Cu2+ on QDs, the microfluidic chip with QD microarray was applied for the determination of Cu2+. 1 nmol/L Cu2+ could be detected by this method.

关键词： microarray quantum dots microfluidic Cu2+

Sediment storage and morphology of the Yalu Tsangpo valley due to uneven uplift of the Himalaya

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2015年第8期58卷 1440-1445页

作者： WANG ZhaoYin yu Guo An WANG XuZhao Charles S. MELCHING liu Le State Key Laboratory of Hydro-Science and Engineering Tsinghua University Key Laboratory of Water Cycle and Related Land Surface Processes Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of Sciences Beijing Institute of Geology for Mineral Resources Environmental Consultant

The fluvial process of the Yalu Tsangpo River occurs concurrently with the uplift of the Qinghai-Tibet ***,the river exhibits unique features in morphology and sediment *** investigations were performed from 2009–2011and the depth of the interface between the sediment deposits and bed rock was detected with an electromagnetic imaging system(EH4)at 29 cross *** deposits were sampled along the Yalu Tsangpo valley from Xietongmen to the Yalu Tsangpo *** results show that a huge amount of sediment has been deposited in four wide valley sections because the uplift rate in these sections was lower than that in the downstream gorge sections over the past million *** 518 billion m3of gravel and sand have been stored in the high mountain river valleys,which has changed the V-shaped mountain river valley into a U-shaped wide river valley in the four *** the sections with high uplift rates the river bed is incised and has formed gorges and the Yalu Tsangpo Canyon.

关键词： Yalu Tsangpo River sediment deposits uneven uplift himalaya wide valley

Two regimes of Atlantic multidecadal oscillation: cross-basin dependent or Atlantic-intrinsic

在线全文

学校读者我要写书评

暂无评论

Science Bulletin 2019年第3期64卷 198-204页

作者： Pengfei Lin Zipeng yu Jianhua Lü Mengrong Ding Aixue Hu Hailong liu State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences University of Chinese Academy of Sciences School of Atmospheric Sciences Guangdong Province Key Laboratory for Climate Change and Natural Disaster Studies Sun Yat-sen University Climate & Global Dynamics National Center for Atmospheric Research(USA)

The Atlantic Multidedal Oscillation(AMO) is a prominent mode of sea surface temperature variability in the Atlantic and incurs significant global influence. Most coupled models failed to reproduce the observed 50–80-year AMO, but were overwhelmed by a 10–30-year AMO. Here we show that the 50–80-year AMO and 10–30-year AMO represent two different AMO regimes. The key differences are:(1) the 50–80-year AMO involves transport of warm and saline Atlantic water into the Greenland-Iceland-Norwegian(GIN)Seas prior to reaching its maximum positive phase, while such a transport is weak for the 10–30-year AMO;(2) the zonality of atmospheric variability associated with the 50–80 year AMO favors the transport of warm and saline water into the GIN Seas;(3) the disappearance of Pacific variability weakens the zonality of atmospheric variability and the transport of warm and saline water into the GIN Seas, leading to the weakening of the 50–80-year AMO. In contrast, the 10–30-year AMO does not show dependence on the variability in Pacific and in the GIN Seas and may be an Atlantic-intrinsic mode. Our results suggest that differentiating these AMO regimes and a better understanding of the cross-basin connections are essential to reconcile the current debate on the nature of AMO and hence to its reliable prediction, which is still lacking in most of coupled models.

关键词： Atlantic multidecadal oscillation Cross-basin interaction Internal climate variability AMO regimes

Reconstruction of broken Si–O–Si bonds in iron ore tailings (IOTs) in concrete

在线全文

学校读者我要写书评

暂无评论

International Journal of Minerals,Metallurgy and Materials 2019年第10期26卷 1329-1336页

作者： Juan-hong liu yu-cheng Zhou Ai-xiang Wu Hong-jiang Wang School of Civil and Resource Engineering University of Science and Technology BeijingBeijing 100083China Beijing Key Laboratory of Urban Underground Space Engineering University of Science and Technology BeijingBeijing 100083China State Key Laboratory of High-efficient Mining and Safety of Metal Mines Ministry of EducationUniversity of Science and Technology BeijingBeijing 100083China

This paper reports a study on the reconstruction of broken Si O Si bonds in iron ore tailings (IOTs) in concrete. Limestone and IOTs were used to investigate the influence of different types of coarse aggregates on the compressive strengths of concrete samples. The dif- ferences in interfacial transition zones (ITZs) between aggregate and paste were analyzed by scanning electron microscopy (SEM) and ener- gy-dispersive spectroscopy (EDS). Meanwhile, X-ray diffraction (XRD) and infrared spectroscopy (IR) were used to study microscopic changes in limestone and IOTs powders in a simple alkaline environment that simulated cement. The results show that the compressive strengths of IOTs concrete or paste are higher than those of limestone concrete or paste under identical conditions. The Ca/Si atom ratios in the ITZs of IOTs con- crete samples are lower than those of limestone concrete;the diffraction peak of the calcium silicate phase at 2θ = 29.5°, as well as the bands of Si O bonds shifting to lower wavenumbers, indicates reconstruction of the broken Si-O-Si bonds on the surfaces of IOTs with Ca(OH)2.

关键词： iron ore tailings broken Si O Si bonds alkaline environment reconstruction

Mass spectrometry-based proteomic approaches to study pathogenic bacteria-host interactions

在线全文

学校读者我要写书评

暂无评论

Protein & Cell 2015年第4期6卷 265-274页

作者： yufei Yang Mo Hu Kaiwen yu Xiangmei Zeng Xiaoyun liu Institute of Analytical Chemistry and Synthetic and Functional Biomolecules Center College of Chemistry and MolecularEnclineerinq Pekinq University Beijing 100871 China

Elucidation of molecular mechanisms underlying host- pathogen interactions is important for control and treatment of infectious diseases worldwide. Within the last decade, mass spectrometry （MS）-based proteomics has become a powerful and effective approach to better understand complex and dynamic host-pathogen inter- actions at the protein level. Herein we will review the recent progress in proteomic analyses towards bacterial infection of their mammalian host with a particular focus on enteric pathogens. Large-scale studies of dynamic proteomic alterations during infection will be discussed from the perspective of both pathogenic bacteria and host cells.

关键词： mass spectrometry proteomics bacterial infection host-pathogen interactions