检索结果-内蒙古大学图书馆

Regulation of morphology and visible light-driven photocatalysis of WO_(3)nanostructures by changing pH

Rare Metals 2021年第7期40卷 1738-1745页

作者： You-Shu Fan Xiao-Li Xi Yang-Si Liu Zuo-Ren Nie Lin-Yan Zhao Qing-Hua Zhang College of Materials Science and Engineering Key Laboratory of Advanced Functional MaterialsEducation Ministry of ChinaBeijing University of TechnologyBeijing 100124China National Engineering Laboratory for Industrial Big-data Application Technology Beijing University of TechnologyBeijing 100124China

The controlled preparation of hexagonal tungsten trioxide(h-WO_(3))nanostructures was achieved by adjusting the pH of the precursor *** effect of the pH on the morphology,elemental composition,and photocatalytic performance of the samples was characterized via X-ray diffraction(XRD),scanning electron microscopy,energy dispersive X-ray spectroscopy,and Raman ***-visible(UV-Vis)spectra were used to evaluate the absorbance and the photocatalytic performance of methylene ***(PL),electrochemical impedance spectroscopy,photocurrent response and Brunauer-Emmett-Teller(BET)were used to study the optical properties,electrical performance,and specific surface area of the WO_(3)-nanostructures,*** results indicate that the WO_(3) nanorods prepared at pH=1.0 exhibit the highest photocatalytic performance(87.4%in 1 h),whereas the WO_(3) nanoblocks prepared at p H=3.0 show the *** photocatalytic performance of the one dimensional(1 D)-nanorods can be attributed to their high specific surface area and charge transfer *** h-WO_(3) nanostructures were synthesized via a simple method and without a capping *** show an excellent photocatalytic performance,which is promising for their application in environment purification.

关键词： h-WO_(3) Morphology pH Photocatalysis Charge transfer Optoelectrical properties

来源：评论

学校读者我要写书评

暂无评论

WOBTree:a write-optimized B+-tree for non-volatile memory

引用

Frontiers of Computer Science 2021年第5期15卷 37-51页

作者： Haitao WANG Zhanhuai LI Xiao ZHANG Xiaonan ZHAO Song JIANG School of Computer Science and Engineering Northwestern Polytechnical UniversityXi'An 710072China Key Laboratory of Big Data Storage and Management Northwestern Polytechnical UniversityMinistry of Industry and Information TechnologyXi'An 710072China National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology Xi’An 710072China Department of Computer Science and Engineering University of Texas at ArlingtonArlingtonTX 76010USA

The emergence of non-volatile memory(NVM)has introduced new opportunities for performance optimizations in existing storage *** better utilize its byte-addressability and near-DRAM performance,NVM can be attached on the memory bus and accessed via load/store memory instructions rather than the conventional block *** this scenario,a cache line(usually 64 bytes)becomes the data transfer unit between volatile and non-volatile ***,the failure-atomicity of write on NVM is the memory bit width(usually 8 bytes).This mismatch between the data transfer unit and the atomicity unit may introduce write amplification and compromise data consistency of node-based data structures such as B+-*** this paper,we propose WOBTree,a Write-Optimized B+-Tree for NVM to address the mismatch problem without expensive *** minimizes the update granularity from a tree node to a much smaller subnode and carefully arranges the write operations in it to ensure crash consistency and reduce write *** results show that compared with previous persistent B+-tree solutions,WOBTree reduces the write amplification by up to 86× and improves write performance by up to 61× while maintaining similar search performance.

关键词： non-volatile memory B+-tree atomic granularity mismatch write amplification performance optimization

来源：评论

学校读者我要写书评

暂无评论

Robust and Trustworthy data Sharing Framework Leveraging On-Chain and Off-Chain Collaboration

引用

Computers, Materials & Continua 2024年第2期78卷 2159-2179页

作者： Jinyang Yu Xiao Zhang Jinjiang Wang Yuchen Zhang Yulong Shi Linxuan Su Leijie Zeng School of Computer Science Northwestern Polytechnical UniversityXi’an710072China MIIT Key Laboratory of Big Data Storage and Management Northwestern Polytechnical UniversityXi’an710072China National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology Northwestern Polytechnical UniversityXi’an710072China

The proliferation of Internet of Things(IoT)systems has resulted in the generation of substantial data,presenting new challenges in reliable storage and trustworthy *** distributed storage systems are hindered by centralized management and lack traceability,while blockchain systems are limited by low capacity and high *** address these challenges,the present study investigates the reliable storage and trustworthy sharing of IoT data,and presents a novel system architecture that integrates on-chain and off-chain data manage *** architecture,integrating blockchain and distributed storage technologies,provides high-capacity,high-performance,traceable,and verifiable data storage and *** on-chain system,built on Hyperledger Fabric,manages metadata,verification data,and permission information of the raw *** off-chain system,implemented using IPFS Cluster,ensures the reliable storage and efficient access to massive files.A collaborative storage server is designed to integrate on-chain and off-chain operation interfaces,facilitating comprehensive data *** provide a unified access interface for user-friendly system *** testing validates the system’s reliability and stable *** proposed approach significantly enhances storage capacity compared to standalone blockchain *** reliability tests consistently yield positive *** average upload and download throughputs of roughly 20 and 30 MB/s,respectively,the system’s throughput surpasses the blockchain system by a factor of 4 to 18.

关键词： On-chain and off-chain collaboration blockchain distributed storage system hyperledger fabric IPFS cluster

来源：评论

学校读者我要写书评

暂无评论

Dynamic OD Prediction for Urban Networks Based on Automatic Number Plate Recognition data: Paramertic vs. Non-parametric Approaches

Dynamic OD Prediction for Urban Networks Based on Automatic ...

引用

2019 IEEE Intelligent transportation Systems Conference, ITSC 2019

作者： Zheng, Fangfang Liu, Jing Zuylen, Henk Van Wang, Kun Liu, Xaobo Li, Jie School of Transportation and Logistics National Engineering Laboratory Integrated Transportation Big Data Application Technology Southwest Jiaotong University 611756 China Civil Engineering College Hunan University Changsha Hunan Province410082 China

ISBN: (纸本)9781538670248

OD flows provide important information for traffic management and planning. In this paper, we propose four OD prediction models based on the data obtained by Automated Number Plate Recognition (ANPR) cameras. The principal component analysis (PCA) is applied to reduce the dimension of the original OD matrices and to separate the main structure patterns from the noisier components. A state-space model is established for the main structure patterns and the structure deviations, and is incorporated in the Kalman filter framework to make prediction. We further develop three K- Nearest Neighbor (K-NN) based pattern recognition approaches. The proposed four approaches are validated with three days' field ANPR data from Changsha city, P.R. China. The results show that on one hand our proposed approaches are able to make accurate prediction of OD flows under different demand conditions. On the other hand, the prediction accuracy is highly dependent on the quality of the available OD data: the Kalman filter model performs better for regular and periodic OD patterns;while for irregular OD matrices K-NN models could make more accurate prediction. © 2019 IEEE.

关键词： Forecasting

来源：评论

学校读者我要写书评

暂无评论

Pedestrian Fundamental Diagram in Between Normal Walk and Crawling 13th

Pedestrian Fundamental Diagram in Between Normal Walk and Cr...

引用

13th Conference on Traffic and Granular Flow, TGF 2019

作者： Ma, Jian Shi, Dongdong Li, Tao School of Transportation and Logistics National Engineering Laboratory of Integrated Transportation Big Data Application Technology Southwest Jiaotong University Chengdu610031 China Faculty of Geosciences and Environmental Engineering Southwest Jiaotong University Chengdu610031 China

ISBN: (纸本)9783030559724

Due to the increase of the number and frequency of major events in the past decades, studies on pedestrian dynamics have attracted attentions of researchers of various disciplines. Considering that escape environment, especially the ones under special circumstances including fire, can be greatly affected by factors such as smoke, pedestrian gait is as a result different from normal walking. Thus an experimental study on fundamental diagram of single-file pedestrian movement at different available heights is detailed in the present paper. In total five experimental scenarios with the available heights of 1.0, 1.2, 1.4, 1.6 and 2.0 m were investigated. The relationship between velocity and density, density and flow, and spatial headway and instantaneous velocity were analyzed. It is found that the pedestrian’s free walking speed is the largest at the height of 2 m. At high density scenarios, the speed of pedestrians presents two separated states, i.e., 0.5 m/s at the heights of 2.0 and 1.6 m and 0.25 m/s at the heights of 1.0, 1.2 and 1.4m. It is also found that there are three segments, namely laminar flow state, stop and go phenomenon and jammed state, in the fundamental diagram. The results presented in this paper is helpful in understanding pedestrian evacuation at different heights. © 2020, Springer Nature Switzerland AG.

关键词： Laminar flow

来源：评论

学校读者我要写书评

暂无评论

Dynamic visual simulation of marine vector field based on LIC——a case study of surface wave field in typhoon condition

引用

Journal of Oceanology and Limnology 2019年第6期37卷 2025-2036页

作者： LIU Zhendong LIU Haixing SU Tianyun JIA Zhen LI Xinfang ZHOU Lin SONG Zhuanling First Institute of Oceanography(FIO) Ministry of Natural Resources(MNR)Qingdao 266061China Laboratory for Regional Oceanography and Numerical Modelling Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology Qingdao 266061China

Line integral convolution(LIC)is a useful visualization technique for a vector ***,the output image produced by LIC has many problems in a marine vector *** focus on the visual quality improvement when LIC is applied in the ocean steady and unsteady flow field in the following *** a white noise is used as the input in a steady flow field,interpolation is used to turn the discrete white noise into continuous white noise to solve the problem of ***"cross"high-pass filtering is used to enhance the textures of streamlines to be more concentrated and continuity strengthened for each *** a sparse noise is used as the input in a steady flow field,we change the directions of background sparse noise according to the directions of vector field to make the streamlines clearer and *** addition,we provide a random initial phase for every streamline to avoid the pulsation effect during *** velocities of vector field are encoded in the speed of the same length streamlines so that the running speed of streamlines can express flow ***,to solve the problem of obvious boundaries when stitching image,we change the streamline tracking *** a white noise is used as an input in an unsteady flow field,double value scattering is used to enhance the contrast of streamlines;moreover,the"cross"high-pass filtering is also adopt instead of two-dimensional high-pass ***,we apply the above methods to a case of the surface wave field in typhoon *** experimental results show that applying the methods can generate high-quality wave images and ***,it is helpful to understand and study waves in typhoon condition to avoid the potential harm of the waves to people's lives and property.

关键词： line integral convolution(LIC) wave data visualization steady and unsteady marine flow field

来源：评论

学校读者我要写书评

暂无评论

Jamming-Aided Secure Communication in Ultra-Dense LEO integrated Satellite-Terrestrial Networks

引用

China Communications 2023年第7期20卷 43-56页

作者： Yongpeng Shi Jiajia Liu Jiadai Wang Yijie Xun School of Physics and Electronic Information Luoyang Normal CollegeLuoyang 471934China National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology School of CybersecurityNorthwestern Polytechnical UniversityXi’an 710072China

The ultra-dense low earth orbit(LEO)integrated satellite-terrestrial networks(UDLEO-ISTN)can bring lots of benefits in terms of wide coverage,high capacity,and strong ***,the broadcasting and open natures of satellite links also reveal many challenges for transmission security protection,especially for eavesdropping *** to efficiently take advantage of the LEO satellite’s density and ensure the secure communication by leveraging physical layer security with the cooperation of jammers deserves further *** our knowledge,using satellites as jammers in UDLEO-ISTN is still a new problem since existing works mainly focused on this issue only from the aspect of terrestrial *** this end,we study in this paper the cooperative secrecy communication problem in UDLEOISTN by utilizing several satellites to send jamming signal to the *** iterative scheme is proposed as our solution to maximize the system secrecy energy efficiency(SEE)via jointly optimizing transmit power allocation and user *** experiment results verify that our designed optimization scheme can significantly enhance the system SEE and achieve the optimal power allocation and user association strategies.

关键词： ultra-dense LEO satellite integrated satellite-terrestrial network physical layer security cooperative jamming

来源：评论

学校读者我要写书评

暂无评论

Study on Valid Travel Route Selection of integrated Passenger transportation 4th

Study on Valid Travel Route Selection of Integrated Passenge...

引用

4th International Conference on Smart Vehicular technology, transportation, Communication and applications, VTCA 2021

作者： Yang, Yao Kan, Chenyan Chen, Dingjun School of Transportation and Logistics Southwest Jiaotong University Chengdu610031 China National and Local Joint Engineering Laboratory of Comprehensive Intelligent Transportation Southwest JiaoTong University Chengdu610031 China National Engineering Laboratory of Integrated Transportation Big Data Application Technology Chengdu610031 China

ISBN: (纸本)9789811640384

With the vigorous development of the integrated transportation network, the choice of passenger travel route is becoming more and more diversified. Therefore, it is important to build the integrated transportation network by establishing the cost function of valid travel route to measure the route that passengers may choose. Based on passenger travel demand, an optimization model of valid route selection for integrated transportation network was established based on generalized travel cost. According to the characteristics of the model, an improved BFS algorithm based on dynamic updating generalized cost function and determining valid travel route by key nodes was designed to solve the valid route. Finally, a simulation was given to verify the effectiveness of the model and algorithm. © 2022, The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd.

关键词： Cost functions

来源：评论

学校读者我要写书评

暂无评论

A modified universal pedestrian motion model: Revisiting pedestrian simulation with bottlenecks

引用

Building Simulation 2022年第4期15卷 631-644页

作者： Jianyu Wang Majid Sarvi Jian Ma Milad Haghani Abdullah Alhawsawi Juan Chen Peng Lin School of Transportation and Logistics Notional Engineering Laboratory of Integrated Transportation Big Data Application TechnologySouthwest Jiaotong UniversityChengdu 610031China Transport Engineering Group Melbourne School of Engineering&ITThe University of MelbourneVictoria 3070Australia Institute of Transport and Logistics Studies Business SchoolThe University of SydneyNSWAustralia Faculty of Geosciences and Environmental Engineering Southwest Jiaotong UniversityChengdu 610031China

Pedestrian flow through narrow exits is one the most important features of crowd dynamics and *** is a particularly important aspect of pedestrian simulation models in that the accuracy is highly dependent on their ability to produce realistic exit flow *** firstly identified the four parameters that are most critical for physical interactions of the social force model and then calibrated them against two well-controlled pedestrian *** these calibrated parameters,we discussed the reasonable settings of sensitive parameters for different levels of pedestrian ***,we revisited the basic questions about the effect of the exit location,the bottleneck length,and the effect of obstacles on pedestrian *** simulation results indicated that:(1)The effect of the exit location on the pedestrian egress efficiency is uncertain,and the evacuation efficiency is also related to the exit width and the level of urgency.(2)The"pass-way"after the exit also named as the bottleneck length has a negative impact on the evacuation performance only in the scenarios that the bottleneck length is not more than 2.0 *** the bottleneck length exceeds 2.0 meters,pedestrian outflow efficiency reaches an asymptotic.(3)Setting an obstacle near an exit is not leading to a longer pedestrian evacuation time,instead,it is effectively improving pedestrian evacuation.

关键词： bottleneck pedestrian crowd simulation exit location bottleneck length obstacles location

来源：评论

学校读者我要写书评

暂无评论

Visual-semantic network: a visual and semantic enhanced model for gesture recognition

引用

Visual Intelligence 2023年第1期1卷 1-13页

作者： Wang, Yizhe Cao, Congqi Zhang, Yanning National Engineering Laboratory for Integrated Aero-Space-Ground-Ocean Big Data Application Technology School of Computer Science Northwestern Polytechnical University Xi’an 710129 China

Gesture recognition has attracted considerable attention and made encouraging progress in recent years due to its great potential in applications. However, the spatial and temporal modeling in gesture recognition is still a problem to be solved. Specifically, existing works lack efficient temporal modeling and effective spatial attention capacity. To efficiently model temporal information, we first propose a long- and short-term temporal shift module (LS-TSM) that models the long-term and short-term temporal information simultaneously. Then, we propose a spatial attention module (SAM) that focuses on where the change primarily occurs to obtain effective spatial attention capacity. In addition, the semantic relationship among gestures is helpful in gesture recognition. However, this is usually neglected by previous works. Therefore, we propose a label relation module (LRM) that takes full advantage of the relationship among classes based on their labels’ semantic information. To explore the best form of LRM, we design four different semantic reconstruction methods to incorporate the semantic relationship information into the class label’s semantic space. We perform extensive ablation studies to analyze the best settings of each module. The best form of LRM is utilized to build our visual-semantic network (VS Network), which achieves the state-of-the-art performance on two gesture datasets, i.e., EgoGesture and NVGesture. © The Author(s) 2023.

关键词： Gesture recognition Semantic relationship Spatial attention Temporal modeling

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：