检索结果-南通市图书馆

Visual exploration of Internet news via sentiment score and topic models

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computational Visual Media 2020年第3期6卷 333-347页

作者： Songye Han Shaojie Ye hongxin zhang Zhejiang University HangzhouChina

Analyzing and understanding Internet news are important for many applications, such as market sentiment investigation and crisis management.However, it is challenging for users to interpret a massive amount of unstructured text, to dig out its accurate meaning, and to spot noteworthy news events.To overcome these challenges, we propose a novel visualization-driven approach for analyzing news text.We first collect Internet news from different sources and encode sentences into a vector representation suitable for input to a neural network, which calculates a sentiment score, to help detect news event patterns. A subsequent interactive visualization framework allows the user to explore the development of and relationships between Internet news topics.In addition, a method for detecting news events enables users and domain experts to interactively explore the correlations between market sentiment, topic distribution, and event patterns. We use this framework to provide a web-based interactive visualization system.We demonstrate the applicability and effectiveness of our proposed system using case studies involving blockchain news.

关键词： interactive Visual overcome

Unregulated emissions from diesel engine with particulate filter using Fe-based fuel borne catalyst

在线全文

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2014年第10期26卷 2027-2033页

作者： Hong Zhao Yunshan Ge Tiezhu zhang Jipeng zhang Jianwei Tan hongxin zhang College of Mechanical & Electronic Engineering Qingdao University National Lab of Auto Performance & Emission Test Beijing Institute of Technology

The alteration and formation of toxic compounds and potential changes in the toxicity of emissions when using after-treatment technologies have gained wide attention. Volatile organic compound（VOC）, carbonyl compound and particle-phase polycyclic aromatic hydrocarbon（PAH） emissions were tested at European Steady State Cycle（ESC） to study unregulated emissions from a diesel engine with a fuel-borne catalyst and diesel particulate filter（FBC–DPF）. An Fe-based fuel-borne catalyst was used for this study. According to the results, brake specific emissions of total VOCs without and with DPF were 4.7 and4.9 mg/kWh, respectively, showing a 4.3% increase. Benzene and n-undecane emissions increased and toluene emission decreased, while other individual VOC emissions basically had no change. When retrofitted with the FBC–DPF, total carbonyl compound emission decreased 15.7%, from 25.8 to 21.8 mg/kWh. The two highest carbonyls, formaldehyde and acetaldehyde, were reduced from 20.0 and 3.7 to 16.5 and 3.3 mg/kWh respectively. The specific reactivity（SR） with DPF was reduced from 6.68 to 6.64 mg/kWh. Total particle-phase PAH emissions decreased 66.4% with DPF compared to that without DPF. However, the Benzo[a]pyrene equivalent（BaPeq） with DPF had increased from 0.016 to 0.030 mg/kWh.Fluoranthene and Pyrene had the greatest decrease, 91.1% and 88.4% respectively. The increase of two- and three-ring PAHs with DPF indicates that the fuel-borne catalyst caused some gas-phase PAHs to adsorb on particles. The results of this study expand the knowledge of the effects of using a particulate filter and a Fe-based fuel-borne catalyst on diesel engine unregulated emissions.

关键词： Fuel-borne catalyst DPF VOCs Carbonyl compounds Particle-phase PAHs

A mini-review on recent progress of new sensitizers for luminescence of lanthanide doped nanomaterials

在线全文

学校读者我要写书评

暂无评论

Nano Research 2020年第7期13卷 1795-1809页

作者： hongxin zhang Zi-Han Chen Xuan Liu Fan zhang Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsState Key Laboratory of Molecular Engineering of Polymers and iChemFudan UniversityShanghai 200433China

Trivalent lanthanide(Ln2+)doped luminescent nanocrystals are promising for applications ranging from biosensor,lasing,super-resolution nanoscopy,information security and so on.Although the utility prospect is of great attractions,the light absorption of these lanthanide doped nanocrystals is inherently weak due to the electric dipole-forbidden 4f→4f transitions.Even worse,the quantum yields of upconverison nanocrystals are very low,which will unavoidably hinder their further applications.In a typical lanthanide luminescent nanosystem,both sensitizers as light absorption centers and activators as light emitting centers are necessary and important for desired luminescence properties.Among various sensitization systems,only Yb3+and Nd+are considered as the most efficient sensitizers.Thus,the corresponding excitation wavelengths are strictly limited around 980 and 808 nm.To enrich excitation wavelengths and boost luminescence intensity,exploring more sensitization units that possess larger absorption cross section,higher efficiency of energy transfer process and independent excitation is imperative and beneficial for the demands of different applications,such as broadened absorption in near infrared(NIR)region for higher conversion efficiency of solar cells,prolonged excitation wavelength to second near infrared windows region(NIR Ⅱ,1,000-1,700 nm)for in vivo fluorescence imaging with deeper tissue depth and higher spatial resolution,more orthogonal excitations and emissions to improve optical multiplexing,and so on.Therefore,in the review,we primarily conclude several major energy transfer mechanisms from sensitizers to activators.Then we present three kinds of sensitizers,including lanthanide ions,organic dyes and quantum dots(QDs),and introduce the newly designed sensitization system that allows us to exploit superior excitation wavelength and amplity luminescence intensity.Finally,several future challenges and opportunities for the sensitizing strategies are discussed in hope of directing and broadening the appli

关键词： lanthanide luminescenee new sensitizers organic dyes quantum dots

基于回音壁模式的空芯光纤光流控DNA传感器

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

光学学报 2024年第9期44卷 191-199页

作者：张洪鑫李雪刚周雪张亚男赵勇东北大学信息科学与工程学院辽宁沈阳110819

针对原位DNA传感的测量需求,提出了一种基于空芯光纤回音壁模式(WGM)的光流控光纤传感器。从仿真和实验两个方面对提出的DNA传感器进行探究。通过仿真探究得到锥形光纤的尺寸、空芯光纤谐振腔的厚度以及锥形光纤和空芯光纤谐振腔的耦合... 详细信息

针对原位DNA传感的测量需求,提出了一种基于空芯光纤回音壁模式(WGM)的光流控光纤传感器。从仿真和实验两个方面对提出的DNA传感器进行探究。通过仿真探究得到锥形光纤的尺寸、空芯光纤谐振腔的厚度以及锥形光纤和空芯光纤谐振腔的耦合间距对WGM的作用规律,在仿真规律的指导下设计和完成实验。实验结果表明,减小谐振腔的厚度可以提高传感器灵敏度,谐振腔厚度为2μm时的折射率灵敏度可达206 nm/RIU,是厚度为4.5μm谐振腔的灵敏度的1.4倍,满足由于DNA分子杂交而在光纤表面产生的局部折射率变化的检测灵敏度要求。通过将探针DNA固定在空芯光纤谐振腔的微流通道,可以实现互补DNA的浓度梯度检测。所提出的传感器的线性检测范围为10~100 nmol/L,灵敏度为0.56 pm/(nmol/L),线性度为0.994。此外,所提出的基于WGM的DNA光纤传感器具有很好的特异性,为原位DNA检测在医学诊断和预后中的应用提供基础。

关键词：医用光学光流控光纤传感器回音壁模式原位DNA传感

End-to-end spatial transform face detection and recognition

在线全文

学校读者我要写书评

暂无评论

Virtual Reality & Intelligent Hardware 2020年第2期2卷 119-131页

作者： hongxin zhang Liying CHI CAD&CG State Key Lab Zhejiang UniversityHangzhou 310058China

Background Several face detection and recogni tion methods have been proposed in the past decades that have excellent performance.The conventional face recognition pipeline comprises the following:(1)face detection,(2)face alignment,(3)feature extraction,and(4)similarity,which are independent of each other.The separate facial analysis stages lead to redundant model calculations,and are difficult for use in end-to-end training.Methods In this paper,we propose a novel end-to-end trainable convolutional network framework for face detection and recognition,in which a geometric transformation matrix is directly learned to align the faces rather than predicting the facial landmarks.In the training stage,our single CNN model is supervised only by face bounding boxes and personal identities,which are publicly available from WIDER FACE and CASIA-WebFace datasets.Our model is tested on Face Detection Dataset and Benchmark(FDDB)and Labeled Face in the Wild(LFW)datasets.Results The results show 89.24%recall for face detection tasks and 98.63%accura cy for face recognition tasks.

关键词： Face detection Face recognition Spatial transform Feature fusion

Prediction of curved oil–water interface in horizontal pipes using modified model with dynamic contact angle

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2020年第3期28卷 698-711页

作者： hongxin zhang Lusheng Zhai Ruoyu Liu Cong Yan Ningde Jin School of Electrical and Information Engineering Tianjin UniversityTianjin 300072China

In this study,interface shapes of horizontal oil–water two-phase flow are predicted by using Young-Laplace equation model and minimum energy model.Meanwhile,the interface shapes of horizontal oil–water twophase flow in a 20 mm inner diameter pipe are measured by a novel conductance parallel-wire array probe(CPAP).It is found that,for flow conditions with low water holdup,there is a large deviation between the model-predicted interface shape and the experimentally measured one.Since the variation of pipe wetting characteristics in the process of fluid flow can lead to the changes of the contact angle between the fluid and the pipe wall,the models mentioned above are modified by considering dynamic contact angle.The results indicate that the interface shapes predicted by the modified models present a good consistence with the ones measured by CPAP.

关键词： Oil–water two-phase flow Curved interface Conductance parallel-wire array probes Dynamic contact angle

COMTIS:Customizable touchless interaction system for large screen visualization

在线全文

学校读者我要写书评

暂无评论

Virtual Reality & Intelligent Hardware 2020年第2期2卷 162-174页

作者： Jiaxin LIU hongxin zhang Chuankang LI CAD&CG State Key Lab Zhejiang UniversityHangzhou 310058China

Background Large screen visualization sys tems have been widely utilized in many industries.Such systems can help illustrate the working states of different production systems.However,efficient interaction with such systems is still a focus of related research.Methods In this paper,we propose a touchless interaction system based on RGB-D camera using a novel bone-length constraining method.The proposed method optimizes the joint data collected from RGB-D cameras with more accurate and more stable results on very noisy data.The user can customize the system by modifying the finite-state machine in the system and reuse the gestures in multiple scenarios,reducing the number of gestures that need to be designed and memorized.Results/Conclusions The authors tested the system in two cases.In the first case,we illustrated a process in which we improved the gesture designs on our system and tested the system through user study.In the second case,we utilized the system in the mining industry and conducted a user study,where users say that they think the system is easy to use.

关键词： Human computer interaction RGB-D camera Touchless interaction Gesture recognition

An Efficient Strategy for Non-probabilistic Reliability-Based Multi-material Topology Optimization with Evidence Theory

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Mechanica Solida Sinica 2019年第6期32卷 803-821页

作者： Qinghai Zhao hongxin zhang Tiezhu zhang Qingsong Hua Lin Yuan Wenyue Wang National and Local Union Engineering Research Center of Electric Vehicle Intelligent Power Integration Technology Qingdao UniversityQingdao 266071China Mechanical and Electrical College Qingdao UniversityQingdao 266071China

It is essential to consider the effects of incomplete measurement,inaccurate information and inadequate cognition on structural topology optimization.For the multi-material structural topology optimization with non-probability uncertainty,the multi-material interpolation model is represented by the ordered rational approximation of mat erial properties(ordered RAMP).Combined with structural compliance minimization,the multi-material topology optimization with reliability constraints is established.The corresponding non-probability uncertainties are described by the evidence theory,and the uniformity processing method is introduced to convert the evidence variables into random variables.The first-order reliability method is employed to search the most probable point under the reliability index constraint,and then the random variables are equivalent to the deterministic variables according to the geometric meaning of the reliability index and sensitivity information.Therefore,the non-probabilistic reliability-based multi-material topology optimization is transformed into the conventional deterministic optimization format,followed by the ordered RAMP method to solve the optimization problem.Finally,through numerical examples of 2D and 3D structures,the feasibility and effectiveness of the proposed method are verified to consider the geometrical dimensions and external loading uncertainties.

关键词： Multi-material Topology optimization Non-probabilistic Reliability Evidence theory

Robust Topology Optimization of Periodic Multi-Material Functionally Graded Structures under Loading Uncertainties

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Computer Modeling in Engineering & Sciences 2021年第5期127卷 683-704页

作者： Xinqing Li Qinghai Zhao hongxin zhang Tiezhu zhang Jianliang Chen College of Mechanical and Electrical Engineering Qingdao UniversityQingdao266071China Power Integration and Energy Storage System Engineering Technology Center Qingdao UniversityQingdao266071China

This paper presents a robust topology optimization design approach for multi-material functional graded structures under periodic constraint with load uncertainties.To characterize the random-field uncertainties with a reduced set of random variables,the Karhunen-Lo`eve(K-L)expansion is adopted.The sparse grid numerical integration method is employed to transform the robust topology optimization into a weighted summation of series of deterministic topology optimization.Under dividing the design domain,the volume fraction of each preset gradient layer is extracted.Based on the ordered solid isotropic microstructure with penalization(Ordered-SIMP),a functionally graded multi-material interpolation model is formulated by individually optimizing each preset gradient layer.The periodic constraint setting of the gradient layer is achieved by redistributing the average element compliance in sub-regions.Then,the method of moving asymptotes(MMA)is introduced to iteratively update the design variables.Several numerical examples are presented to verify the validity and applicability of the proposed method.The results demonstrate that the periodic functionally graded multi-material topology can be obtained under different numbers of sub-regions,and robust design structures are more stable than that indicated by the deterministic results.

关键词： Multi-material topology optimization robust design periodic functional gradient sparse grid method