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Differentially Private Spatial Decompositions for Geospatial Point Data

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China Communications 2016年第4期13卷 97-107页

作者： WANG Jun liU Shubo li yongkai CAO Hui liU Mengjun School of computer Wuhan University Key Laboratory of Aerospace Information security and trusted computing Ministry of Education Wuhan University

Technological advancements in data analysis and data releasing have put forward higher security requirements, such as privacy guarantee and strictly provable security, this new area of research is called differential privacy. As for geospatial point data, the exiting methods use the tree structure to split the data space to enhance the data utility and usually adopt uniform budgeting method. Different from this, we propose a novel non-uniform allocation scheme for privacy budget which is a parameter to specify the degree of privacy guarantee. Firstly, the spatial data is indexed by quadtree, then, different privacy budget is allocated to each layer of quadtree using Fibonacci series features, and we designate this budgeting method as Fibonacci allocation. Experimental results show that Fibonacci allocation is significantly more accurate in data queries than the state-of-the-art methods under the same privacy guarantee level and fits for arbitrary range queries. Furthermore, data utility can be improved by post-processing and threshold determination.

关键词： privacy guarantee Fibonacci allocation quadtree differential privacy

Curved display based on programming origami tessellations

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Microsystems & Nanoengineering 2021年第6期7卷 197-206页

作者： Yang Deng Weixuan liu Yik Kin Cheung yongkai li Wei Hong Hongyu Yu Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyKowloonHong Kong SAR 999077China Department of Mechanics and Aerospace Engineering Southern University of Science and Technology(SUSTech)ShenzhenGuangdongChina

Curved displays have recently become very popular,with wide applications for both industry and ***,built upon initially flat films,most flexible displays are often incompatible with general nondevelopable *** this paper,we report a method for producing curved displays of nondevelopable shapes by using a structure-mechanics-inspired functional optimization method to design tessellation patterns that fold into the desired *** displays in spherical and saddle shapes are *** microfabrication process is employed for manufacturing 2D flexible foldable circuit boards,pick-and-place technology is used for placing illuminant elements onto the boards,and mold guidance is used for folding 2-D sheets into curved 3D display *** proposed technology is feasible for mass production and advances the application of next-generation curved displays.

关键词： curved programming initially

A new method used for reservoir production performance analysis

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Petroleum 2019年第1期5卷 30-34页

作者： Shuyong Hu Yi Deng yongkai li Ran Wang State Key Laboratory of Oil&Gas Reservoir Geology Exploitation Engineering Southwest Petroleum UniversityChengduPeople's Republic of China Sulige Project Management Department CCDCOrdosPeople's Republic of China

Water flooding type-curves,recently receiving increasing attentions,play an essential role in evaluation of OOIP and prediction of future *** study proposed a method modified form Weibull model and water flooding type-curves to analyze the reservoir production performance,including predication of oil production and water injection *** results indicate that the method can estimate and provide solutions for oil production,water injection rate and injection-production ratio with a well accuracy.A case study is conducted to demonstrate the applicability and accuracy of model by field *** matching results illustrate a good accordance between calculated values and field data.

关键词： Weibull model Water flooding type-curves Oil production Water injection rate Injection-production ratio

Privacy-preserving Distributed Location Proof Generating System

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China Communications 2016年第3期13卷 203-218页

作者： liU Mengjun liU Shubo ZHANG Rui li yongkai WANG Jun CAO Hui Key Laboratory of Aerospace Information security and trusted computing Ministry of Education Wuhan University School of computer Wuhan University Department of Electronic Engineering University of Hawaii

The rapid development of location-based service(LBS) drives one special kind of LBS, in which the service provider verifies user location before providing services. In distributed location proof generating schemes, preventing users from colluding with each other to create fake location proofs and protecting user's location privacy at the same time, are the main technical challenges to bring this kind of LBS into practical. Existing solutions tackle these challenges with low collusion-detecting efficiency and defected collusion-detecting method. We proposed two novel location proof generating schemes, which inversely utilized a secure secret-sharing scheme and a pseudonym scheme to settle these shortcomings. Our proposed solution resists and detects user collusion attacks in a more efficient and correct way. Meanwhile, we achieve a higher level of location privacy than that of previous work. The correctness and efficiency of our proposed solution is testified by intensive security analysis, performance analysis, as well as experiments and simulation results.

关键词： computer software and theory location proof secret-sharing location privacy

Miura-ori enabled stretchable circuit boards

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npj Flexible Electronics 2021年第1期5卷 9-17页

作者： yongkai li Weixuan liu Yang Deng Wei Hong Hongyu Yu Department of Mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyClear Water BayHong KongChina Smart Manufacturing Thrust Systems HubThe Hong Kong University of Science and Technology(Guangzhou)NanshaGuangzhouGuangdongChina Department of Mechanics and Aerospace Engineering Southern University of Science and TechnologyShenzhenGuangdongChina

Origami,an ancient form of papercraft,provides a way to develop functional structures for engineering *** this paper,we report an approach to design and manufacture a stretchable circuit board(SCB)with origami *** benefits of developable,flat-foldable,and rigid-foldable origami-based structures as SCBs are discussed,and a representative structure,Miura fold(or Miura-ori),is chosen to be *** the constraints induced by the mounted components’dimensions,the Miura-ori structures for specific applications can be *** propose three methods for better fabrication,including direct folding,stiffness modification,and kirigami enhancement,to improve a planar sheet’s foldability.A wearable ECG(electrocardiogram)system based on MO-SCB(Miura-ori enabled SCB)technology is built,and the stretchable portion is made of commercial FPCBs(flexible printed circuit board),providing desired stretchability and *** proposed technology routine is compatible with industrial production and may pave the application of stretchable electronics.

关键词： Miura mounted dimensions

A new approach of proration-injection allocation for water-flooding mature oilfields

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Petroleum 2015年第1期1卷 27-30页

作者： Shuyong Hu yongkai li Ziwei Wang Guoqiang Hu State Key Laboratory of Oil&Gas Reservoir Geology Exploitation Engineering Southwest Petroleum UniversityChengduSichuanPeople's Republic of China

This paper presents a new method of injection-production allocation estimation for water-flooding mature *** suggested approach is based on logistic growth rate functions and several type-curve matching *** the relationship between these equations,oil production and water injection rate as well as injection-production ratio can be easily *** calculation procedure developed and outlined in this paper requires very few production data and is easily ***,an oilfield case has been *** synthetic and field cases validate the calculation procedure,so it can be accurately used in forecasting production data,and it is important to optimize the whole injection-production system.

关键词： Logistic growth models Injection-production allocation Oil production Water injection rate Injection-production ratio

Single crystal growth and characterization of 166-type magnetic kagome metals

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Chinese Physics B 2024年第9期33卷 145-150页

作者： Huangyu Wu Jinjin liu yongkai li Peng Zhu liu Yang Fuhong Chen Deng Hu Zhiwei Wang Centre for Quantum Physics Key Laboratory of Advanced Optoelectronic Quantum Architecture and Measurement(MOE)School of PhysicsBeijing Institute of TechnologyBeijing 100081China Beijing Key Laboratory of Nanophotonics and Ultrafine Optoelectronic Systems Beijing Institute of TechnologyBeijing 100081China Beijing Institute of Technology Zhuhai 519000China Material Science Center Yangtze Delta Region Academy of Beijing Institute of TechnologyJiaxing 314011China

Kagome magnets were predicted to be a good platform to investigate correlated topology band structure,Chern quantum phase,and geometrical frustration due to their unique lattice *** we reported single crystal growth of 166-type kagome magnetic materials,including HfMn_(6)Sn_(6),ZrMn_(6)Sn_(6),GdMn_(6)Sn_(6)and GdV_(6)Sn_(6),by using the flux method with Sn as the *** them,HfMn_(6)Sn_(6)and ZrMn_(6)Sn_(6)single crystals were grown for the first time.X-ray diffraction measurements reveal that all four samples crystallize in HfFe6Ge6-type hexagonal structure with space group P6/*** samples show metallic behavior from temperature dependence of resistivity measurements,and the dominant carrier is hole,except for GdV6Sn6 which is electron *** samples have magnetic order with different transition temperatures,HfMn_(6)Sn_(6),ZrMn_(6)Sn_(6)and GdV_(6)Sn_(6)are antiferromagnetic with TN of 541 K,466 K and 4 K respectively,while GdMn_(6)Sn_(6)is ferrimagnetic with the critical temperature of about 470 *** study will enrich the research platform of magnetic kagome materials and help explore the novel quantum phenomena in these interesting *** dataset of specific crystal structure parameters for HfMn_(6)Sn_(6)are available in Science Data Bank,with the link.

关键词： kagome metal single crystal growth crystal structure physical property

Weakened interlayer coupling in two-dimensional MoSe2 flakes with screw dislocations

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Nano Research 2019年第8期12卷 1900-1905页

作者： Xiangzhuo Wang Huixia Yang Rong Yang Qinsheng Wang Jingchuan Zheng Lu Qiao Xianglin Peng yongkai li Dongyun Chen Xiaolu Xiong Junxi Duan Guangyu Zhang Jie Ma Junfeng Han Wende Xiao Yugui Yao Key Lab of Advanced Optoelectronic Quantum Architecture and Measurement (MOE) Beijing Key Lab of Nanophotonics & Ultrafine Optoelectronic Systemsand School of PhysicsBeijing Institute of TechnologyBeijing 100081China Micronano Center Beijing Institute of TechnologyBeijing 100081China Institute of Physics Chinese Academy of SciencesBeijing 100190China

The screw dislocations are intriguing defects that are often observed in natural and artificial materials. The dislocation spirals break the reflection and inversion symmetries of the lattices and modify the interlayer coupling in layer-structured materials, inducing additional complexity in layer stacking and thus novel properties in materials. Here, we report on the interlayer coupling of two-dimensional (2D) MoSe2 flakes with screw dislocations by atomic force microscopy (AFM), Raman spectra and photoluminescence (PL) spectra. By controlling the supersaturation conditions, 2D MoSe2 flakes with screw dislocations are grown on amorphous SiO2 substrates by chemical vapor deposition (CVD). AFM measurements reveal that the interlayer spacing in such 2D MoSe2 flakes with screw dislocation is slightly widened with respect to the normal AA- or AB-stacked ones due to the presence of the screw dislocations. Raman and PL spectra show that the interlayer coupling is weaker and thus the band gap is wider than that in the normal AA- or AB-stacked ones. Our work demonstrates that the interlayer coupling of 2D transition metal dichalcogenides (TMDCs) flakes can be tuned by the induction of screw dislocations, which is very helpful for developing novel catalysts and electronic devices.

关键词： transition-metal dichalcogenides molybdenum selenide screw dislocations interlayer coupling band gap

Food-Borne Poisoning Accident from Amanitin Toxin in Wild Mushrooms—Xingtai City,Hebei Province,China,2023

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China CDC weekly 2024年第3期6卷 56-59页

作者： Baopu Lv liang liu Hao Xiao Qingbing Meng Rui Zhang Yaqing An Yingli Jin Yu Ma Hengbo Gao yongkai li Qian He Yutao Zhang Changqing liu Xiaoyan Luo Xiaomin Xu Fenshuang Zheng Yingping Tian Hongshun Zhang Dongqi Yao Emergency Department The Second Hospital of Hebei Medical UniversityShijiazhuang CityHebei ProvinceChina National Institute of Occupational Health and Poison Control Chinese Centre for Disease Control and PreventionBeijingChina Hebei Provincial Center for Disease Control and Prevention Shijiazhuang CityHebei ProvinceChina Zhejiang Provincial Center for Disease Control and Prevention Hangzhou CityZhejiang ProvinceChina Emergency Department The Affiliated Hospital of Yunnan UniversityKunming CityYunnan ProvinceChina

What is already known about this topic?Fatal poisonings caused by wild mushrooms containing amanita toxins pose a significant threat in the southern regions of *** toxins primarily induce gastrointestinal symptoms initially,which are then followed by potentially life-threatening acute liver *** is added by this report?This report contributes to the existing knowledge on these cases of poisoning by documenting the second occurrences in Hebei Province and the first occurrences in Xingtai *** individuals reported consuming wild mushrooms from the same origin,and laboratory tests confirmed the presence ofα-amanitin in their blood *** are the implications for public health practice?This underscores the risk associated with the collection and consumption of amanita toxin-containing mushrooms in *** is important to note that the identification of toxic and non-toxic mushrooms should not solely rely on personal experience or appearance.

关键词： Hebei consuming initially