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Mobile crowd sensing task optimal allocation： a mobility pattern matching perspective

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Frontiers of Computer Science 2018年第2期12卷 231-244页

作者： Liang WANG zhiwen yu Bin GUO Fei YI Fei XIONG School of Computer Science Northwestern Polytechnical University Xi'an 710072 China School of Electrical and Control Engineering Xi'an University of Science and Technology Xi'an 710054 China School of Electronic and Information Engineering Beijing Jiaotong University Beijing 100044 China

With the proliferation of sensor-equipped portable mobile devices, Mobile CrowdSensing （MCS） using smart devices provides unprecedented opportunities for collecting enormous surrounding data. In MCS applications, a crucial issue is how to recruit appropriate participants from a pool of available users to accomplish released tasks, satisfying both resource efficiency and sensing quality. In order to meet these two optimization goals simultaneously, in this paper, we present a novel MCS task allocation framework by aligning existing task sequence with users＇ moving regularity as much as possible. Based on the process of mobility repetitive pattern discovery, the original task allocation problem is converted into a pattern matching issue, and the involved optimization goals are transformed into pattern matching length and support degree indicators. To determine a trade-off between these two competitive metrics, we propose greedy- based optimal assignment scheme search approaches, namely MLP, MDP, IU1 and IU2 algorithm, with respect to matching length-preferred, support degree-preferred and integrated utility, respectively. Comprehensive experiments on real- world open data set and synthetic data set clearly validate the effectiveness of our proposed framework on MCS task optimal allocation.

关键词： mobile crowd sensing task allocation mobility regularity pattern matching

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HPLC法测定龙牡壮骨颗粒中甘草酸的含量

中国中医药现代远程教育 2024年第15期22卷 157-158,202页

作者：付志文彭丹余中霞江西康恩贝中药有限公司技术部江西上饶334400 江西省儿童医院药学部江西南昌330000 上饶市检验检测认证院药品检测分院江西上饶334000

目的建立以高效液相色谱法(HPLC)测定龙牡壮骨颗粒中甘草酸含量的方法。方法采用Capcell pak C18(250 mm×4.6 mm,5μm)色谱柱,以乙腈-0.1%磷酸溶液(40∶60)为流动相,流速为1.0 mL/min,柱温为30℃,进样量为20μL,检测波长为254 nm。结... 详细信息

目的建立以高效液相色谱法(HPLC)测定龙牡壮骨颗粒中甘草酸含量的方法。方法采用Capcell pak C18(250 mm×4.6 mm,5μm)色谱柱,以乙腈-0.1%磷酸溶液(40∶60)为流动相,流速为1.0 mL/min,柱温为30℃,进样量为20μL,检测波长为254 nm。结果甘草酸铵在质量浓度为0.814~40.70μg/mL范围内与峰面积呈良好的线性关系[相关系数(r)≥0.999],平均加样回收率为96.52%[相对标准偏差(RSD)为0.85%]。结论此实验所建立的方法简便、准确、专属性强,测定结果重复性好,可为龙牡壮骨颗粒的质量控制提供依据。

关键词：龙牡壮骨颗粒甘草酸高效液相色谱法含量测定

Progress of rechargeable lithium metal batteries based on conversion reactions

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National Science Review 2017年第1期4卷 54-70页

作者： Sen Xin zhiwen Chang Xinbo Zhang yu-Guo Guo CAS Key Laboratory of Molecular Nanostructure and Nanotechnology Institute of ChemistryChinese Academy of Sciences (CAS) State Key Laboratory of Rare Earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of Sciences School of Chemistry and Chemical Engineering University of Chinese Academy of Sciences

In this review,we focus on the conversion reaction in newly raised rechargeable lithium bateries instanced by lithium–sulfur and lithium–oxygen bateries.A comprehensive discussion is made on the fundamental electrochemistry and recent advancements in key components of both types of the *** critical problems in the Li–S and Li–O2conversion electrochemistry are addressed along with the corresponding improvement strategies,for the purpose of shedding light on the rational design of bateries to reach optimal performance.

关键词： energy storage conversion reaction lithium–sulfur batery lithium–oxygen batery

Low-complexity polar code construction for higher order modulation

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Science China(Information Sciences) 2019年第10期62卷 206-207页

作者： Yongrun yu zhiwen PAN Nan LIU Xiaohu YOU National Mobile Communications Research Laboratory Southeast University

Dear editor,Polar codes can achieve the symmetric capacity of binary-input memoryless channels with infinite code length under successive cancellation (SC) decoding [1]. Cyclic redundancy check (CRC) aids in successive cancellation list (CA-SCL)[2, 3] and a decoder is proposed to improve the finite length performance of polar codes. To achieve the spectrum efficiency required by next generation wire-

关键词： Carlo Monte QAM CRC SCL Low-complexity polar code construction for higher order modulation

The mass,fake news,and cognition security

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Frontiers of Computer Science 2021年第3期15卷 1-13页

作者： Bin GUO Yasan DING yueheng SUN Shuai MA Ke LI zhiwen yu School of Computer Science Northwestern Polytechnical UniversityXi'an 710072China School of Cyber Security Tianjin UniversityTianjin 300350China School of Computer Science and Engineering Beihang UniversityBeijing 100191China

The widespread fake news in social networks is posing threats to social stability,economic development,and political democracy,*** studies have explored the effective detection approaches of online fake news,while few works study the intrinsic propagation and cognition mechanisms of fake *** the development of cognitive science paves a promising way for the prevention of fake news,we present a new research area called Cognition Security(CogSec),which studies the potential impacts of fake news on human cognition,ranging from misperception,untrusted knowledge acquisition,targeted opinion/attitude formation,to biased decision making,and investigates the effective ways for fake news *** is a multidisciplinary research field that leverages the knowledge from social science,psychology,cognition science,neuroscience,AI and computer *** first propose related definitions to characterize CogSec and review the literature *** further investigate the key research challenges and techniques of CogSec,including human-content cognition mechanism,social influence and opinion dif-fusion,fake news detection,and malicious bot ***,we summarize the open issues and future research directions,such as the cognition mechanism of fake news,influence maximization of fact-checking information,early detection of fake news,fast refutation of fake news,and so on.

关键词： cyberspace cognition security fake news crowd computing human-content interaction

Spotlight: Hot Target Discovery and Localization with Crowdsourced Photos

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Tsinghua Science and Technology 2020年第1期25卷 68-80页

作者： Jiaxi Gu Jiliang Wang Lan Zhang zhiwen yu Xiaozhe Xin yunhao Liu School of Computer Science Northwestern Polytechnical UniversityXi’an 710072China School of Software Tsinghua UniversityBeijing 100084China School of Computer Science and Technology University of Science and Technology of ChinaHefei 230026China Beijing Sogou Technology Development Co. Ltd.Beijing 100084China

Camera-equipped mobile devices are encouraging people to take more photos and the development and growth of social networks is making it increasingly popular to share photos online. When objects appear in overlapping Fields Of View(FOV), this means that they are drawing much attention and thus indicates their popularity. Successfully discovering and locating these objects can be very useful for many applications, such as criminal investigations, event summaries, and crowdsourcing-based Geographical Information Systems(GIS).Existing methods require either prior knowledge of the environment or intentional photographing. In this paper, we propose a seamless approach called 'Spotlight', which performs passive localization using crowdsourced *** a graph-based model, we combine object images across multiple camera views. Within each set of combined object images, a photographing map is built on which object localization is performed using plane geometry. We evaluate the system’s localization accuracy using photos taken in various scenarios, with the results showing our approach to be effective for passive object localization and to achieve a high level of accuracy.

关键词： crowdsourcing localization multimedia mobile computing

Quantifying predictability of sequential recommendation via logical constraints

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Frontiers of Computer Science 2023年第5期17卷 133-143页

作者： En XU zhiwen yu Nuo LI Helei CUI Lina YAO Bin GUO School of Computer Science Northwestern Polytechnical UniversityXi’an 710129China School of Computer Science and Engineering University of New South WalesSydney NSW 2052Australia

The sequential recommendation is a compelling technology for predicting users’next interaction via their historical *** studies have proposed various methods to optimize the recommendation accuracy on different datasets but have not yet explored the intrinsic predictability of sequential *** this end,we consider applying the popular predictability theory of human movement behavior to this recommendation ***,it would incur serious bias in the next moment measurement of the candidate set size,resulting in inaccurate ***,determining the size of the candidate set is the key to quantifying the predictability of sequential ***,different from the traditional approach that utilizes topological constraints,we first propose a method to learn inter-item associations from historical behaviors to restrict the size via logical ***,we extend it by 10 excellent recommendation algorithms to learn deeper associations between user *** two methods show significant improvement over existing methods in scenarios that deal with few repeated behaviors and large sets of ***,a prediction rate between 64%and 80%has been obtained by testing on five classical datasets in three domains of the recommender *** provides a guideline to optimize the recommendation algorithm for a given dataset.

关键词： sequential recommendation information theory predictability

Insight into macroscale superlubricity of polyol aqueous solution induced by protic ionic liquid

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Friction 2022年第12期10卷 2000-2017页

作者： zhiwen ZHENG Xiaolong LIU Hongxiang yu Haijie CHEN Dapeng FENG Dan QIAO State Key Laboratory of Solid Lubrication Lanzhou Institute of Chemical PhysicsChinese Academy of SciencesLanzhou 730000China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Currently,macroscale liquid superlubricity remains limited to low applied loads and typical ceramic friction *** this study,a robust macroscale superlubricity with a coefficient of friction(COF)of approximately 0.006 is realized at the bearing steel interface induced by protic ionic liquids(ILs)in propylene glycol aqueous solution,and the lubrication system exhibits excellent anti-corrosion *** show that superlubricity can be achieved by employing ILs with longer alkyl chains over a wide load(700 r/min)*** systematically investigating factors affecting superlubricity,including the IL structure,ionization degree,test conditions,polyol,water-to-alcohol ratio,and lubrication state,the superlubricity mechanism is ***,a thicker and denser stern layer can be formed using ILs with longer alkyl chains,which participates in the tribochemical reaction with the metal substrate to form a tribofilm during *** hydrogen bond network layer formed by the hydrogen ion and polycol aqueous solution can withstand high applied *** can be used to reduce the shear stress of polyols,and enable superlubricity to be achieved under high-speed ***,an inevitable running-in period serves as a dispersing contact stress and dynamically forms a lubricating film,where the lubrication state locates mixed lubrication and then transforms into boundary lubrication as the roughness of the contact surface *** study is expected to significantly promote the development and application of superlubricity in the engineering field.

关键词： macroscale superlubricity ionic liquids(ILs) steel interface corrosion tribochemical reaction

计及信誉值的虚拟电厂多主体合作博弈交易方法

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广东电力 2024年第8期37卷 26-34页

作者：王桂兰卓怀宇卢建刚余志文赵瑞锋华北电力大学控制与计算机工程学院河北保定071003 广东电网有限责任公司电力调度控制中心广东广州510600

随着分布式资源高比例接入,虚拟电厂作为聚合多方交易主体参与电力市场的新兴技术逐渐受到广泛关注。然而分布式资源出力不确定性和个体趋利性可能导致参与电力交易过程中造成违约行为。因此,提出计及信誉值的虚拟电厂聚合多方主体参与... 详细信息

随着分布式资源高比例接入,虚拟电厂作为聚合多方交易主体参与电力市场的新兴技术逐渐受到广泛关注。然而分布式资源出力不确定性和个体趋利性可能导致参与电力交易过程中造成违约行为。因此,提出计及信誉值的虚拟电厂聚合多方主体参与合作博弈电力交易方法。首先,针对虚拟电厂内各交易主体建立基于合约电量完成度的信誉值管理机制,并构建基于收益最大化的多主体合作出力模型;其次,采用合作博弈理论的Shapley值法确定初始收益分配方案;再次,为激励交易主体积极履行交易合约,合理转移交易风险,引入信誉值对初始方案进行修正,得出改进的收益分配方案;最后,基于MATLAB对算例进行计算,结果表明:合作前后各交易主体收益合计增长率约为101.16%,对比传统Shapley值法收益分配方案,最高和最低信誉值交易主体的收益增减幅度分别约为1.04%和3.13%,验证了所提交易方法的有效性与合理性。

关键词：虚拟电厂合作博弈信誉值 Shapley值法电力交易

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