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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

The Performance of Dual-Frequency Polarimetric Scatterometer in Sea Surface Wind Retrieval

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Journal of Ocean University of China 2019年第5期18卷 1051-1060页

作者： liu shubo WEI Enbo JIN Xu LV Ailing DANG Hongxing Xi’an Institute of Space Radio Technology China Academy of Space TechnologyXi’an 710100China National Key Laboratory of Science and Technology on Space Microwave Xi’an 710100China Institute of Oceanology and Center for Ocean Mega-Science Chinese Academy of Sciencesand Qingdao National Laboratory for Marine Science and TechnologyQingdao 266071China

The wind retrieval performance of HY-2 A scanning scatterometer operating at Ku-band in HH and VV polarizations has been well evaluated in the wind speed range of 0–25 m s^-*** order to obtain more accurate ocean wind field,a potential extension of dual-frequency(C-band and Ku-band)polarimetric measurements is investigated for both low and very high wind speeds,from 5 to 45 m s^-*** on the geophysical model functions of C-band and Ku-band,the simulation results show that the polarimetric measurements of Ku-band can improve the wind vector retrieval over the entire scatterometer swath,especially in nadir area,with the wind direction root-mean-square error(RMSE)less than 12?in the wind speed range of 5–25 m s^-***,the results also show that C-band cross-polarization plays a very important role in improving the wind speed retrieval,with the wind speed retrieval accuracy better than 2 m s^-1 for all wind conditions(0–45 m s^-1).For extreme winds,the C-band HH backscatter coefficients modeled by CMOD5.N(H)and the ocean co-polarization ratio model at large incidence are used to retrieve sea surface wind *** result reveals that there is a big decrease of wind direction retrieval RMSE for extreme wind fields,and the retrieved result of C-band HH polarization is nearly the same as that of C-band VV polarization for low-to-high wind speed(5–25 m s^-1).Thus,to improve the wind retrieval for all wind conditions,the dual-frequency polarimetric scatterometer with C-band and Ku-band horizontal polarization in inner beam,and C-band horizontal and Ku-band vertical polarization in outer beam,can be used to measure ocean *** study will contribute to the wind retrieval with merged satellites data and the future spaceborne scatterometer.

关键词： dual-frequency polarimetric scatterometer wind vector retrieval

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

Brightness Temperature Model of Sea Foam Layer at L-band

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Journal of Ocean University of China 2015年第1期14卷 38-46页

作者： liu shubo JIA Yanxia QI Zhen WEI Enbo Institute of Oceanology Chinese Academy of Sciences University of Chinese Academy of Sciences Hisense Trans-Tech Company Limited Cangzhou City Marine Environment Monitoring Station

Permittivity of a sea foam layer is very important in investigating ocean brightness temperature model. At microwave frequency, the Rayleigh method is developed to estimate the effective permittivity of the sea foam layer. To simplify the tedious calculation of sea foam effective permittivity at L band （1.4GHz）, Pade＇ approximation is adopted to fit the sea foam effective permittivity computed by the Rayleigh method. With this fitting formula, a new brightness temperature model of sea foam layer defined by certain geophysical parameters, such as air volume fraction （AVF）, sea surface temperature （SST）, sea surface salinity （SSS） and thickness of foam layer d, is given. Furthermore, the sensitivities of the brightness temperature model to SST, SSS, d and AVF of a sea foam layer at L band are discussed. The sensitivities are ranked from most to least in the order：（1） d; （2） AVF; （3） SSS; （4） SST. This result indicates that the measurement errors old and AVF have significant impacts on the retrievals of SSS and SST. With the experimental brightness temperature data, the SSS and AFV are retrieved by cost function.

关键词： sea foam permittivity Rayleigh method Pade' approximation

Security Enhancement of Arbiter-Based Physical Unclonable Function on FPGA

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Wuhan University Journal of Natural Sciences 2017年第2期22卷 127-133页

作者： WANG Jun liu shubo XIONG Xingxing LIANG Cai Key Laboratory of Aerospace Information Security and Trusted Computing Ministry of Education Wuhan University Wuhan 430072 Hubei China School of Computer Wuhan University Wuhan 430072Hubei China

In order to reduce physical unclonable fixnction （PUF） response instability and imbalance caused by the metastability and the bias of arbiter, this paper uses an improved balanced D flip-plop （DFF） based on the unbalanced DFF to reduce the bias in response output and enhances the security of PUF by adopting two balanced DFFs in series. The experimental results show that two cascaded balanced DFFs improve the stability of the DFF, and the output of two balanced DFFs is more reliable. The entropy of output is fixed at 98.7%.

关键词： physical unclonable function metastability balanced D flip-flop field programmable gate arrays (FPGA) security

Cross-talk between biometal ions and immune cells for bone repair

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Engineered Regeneration

Engineered Regeneration 2024年第3期5卷 375-408页

作者： shubo liu Zhengjie Lin Wei Qiao Bin Chen Jie Shen Division of Orthopaedics and Traumatology Department of OrthopaedicsNanfang HospitalSouthern Medical UniversityGuangzhouPR China D Printing Clinical Translational and Regenerative Medicine Center Department of StomatologyShenzhen Qianhai Shekou Free Trade Zone HospitalShenzhenPR China Shenzhen Key Laboratory of Spine Surgery Department of Spine SurgeryPeking University Shenzhen HospitalShenzhenPR China Applied Oral Sciences and Community Dental Care Faculty of DentistryThe University of Hong KongHong Kong S.A.R.PR China

Biometal ions are crucial in the structure and function of living organisms and have extensively been employed to promote bone tissue ***,the biological functions of biometal ions and the underlying mechanisms responsible for their pro-regenerative effects remain incompletely understood,since bone repair is an intricate physiological process involving multiple cell types and *** accomplishments in the osteoim-munological field have revealed the momentous involvement of the immune system in mediating the therapeutic effects of biometal *** inflammatory factors secreted by immune cells contribute to bone cell migration,activation,and *** review summarizes the immune system and its constituent cells,followed by the current perspective on immunomodulation during bone ***,the physicochemical and physiological properties of various biometal ions,including lithium,sodium,potassium,magnesium,calcium,strontium,vana-dium,iron,cobalt,copper,and zinc,are thoroughly *** addition,the interactions between biometal ions,immune cells,and bone tissue are discussed,aiming to provide insights into the prospective development of novel approaches to bone tissue regeneration by harnessing the therapeutic potential of these biometal ions.

关键词： Metal ion Bone regeneration Bone repair Immune cell Osteo-immunomodulation

Differentially Private Top-k Items Based on Least Mean Square——Take E-Commerce Platforms for Example

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Wuhan University Journal of Natural Sciences 2019年第2期24卷 98-106页

作者： CAO Mengyue WU Fusheng NI Mingtao XIONG Xingxing liu shubo WANG Jun Department of Foreign Languages Yangtze University College of Arts and Sciences Guizhou Key Laboratory of Economics System Simulation Guizhou University of Finance and Economics School of Cyber Science and Engineering Wuhan University School of Computer Science Leshan Normal University School of Computer Wuhan University College of Computer South-Central University for Nationalities

User preference data broadly collected from e-commerce platforms have benefits to improve the user’s experience of individual purchasing recommendation by data mining and analyzing,which may bring users the risk of privacy *** this paper,we explore the problem of differential private top-k items based on least mean ***,we consider the balance between utility and privacy level of released data and improve the precision of top-k based on *** show that our algorithm can achieve differential privacy over streaming data collected and published periodically by server *** evaluate our algorithm with three real datasets,and the experimental results show that the precision of our method reaches 85%with strong privacy protection,which outperforms the Kalman filter-based existing methods.

关键词： top-k differential privacy least mean square streaming data

Reverse Engineering Analysis Based on Differential Fault Analysis Against Secret S- boxes

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China Communications 2012年第10期9卷 10-22页

作者： Tang Ming Qiu Zhenlong Deng Hui liu shubo Zhang Huanguo State Key Laboratory of AIS & TC Ministry of Education Wuhan University Wuhan 430072 P. R. China School of Computers Wuhan University Wuhan 430072 P. R. China

To evaluate the security of cipher algo- rithrrs with secret operations, we built a new reverse engineering analysis based on Differential Fault Analysis （DFA） to recover the secret S-boxes in Secret Private Network （SPN） and Feistel structures, which are two of the most typical structures in block ciphers. This paper gives the general definitions of these two structures and proposes the reverse engineering analysis of each structure. Furthermore, we evaluate the complexity of the proposed reverse analyses and theoretically prove the effectiveness of the reverse method. For the Twoflsh-like and AES-like algorithrm, the experimental results verify the correctness and efficiency of the reverse analysis. The proposed reverse analysis can efficiently recover the secret S-boxes in the encryp＇don algorithms writh SPN and Feistel structures. It can successfully recover the Twoflsh- like algorithm in 2.3 s with 256 faults and the AES- like algorithm in 0.33 s with 23 faults.

关键词： DFA reverse engmeenng analysis block cipher SPN feistel S-box

Novel injectable adhesive hydrogel loaded with exosomes for holistic repair of hemophilic articular cartilage defect

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Bioactive Materials 2024年第12期42卷 85-111页

作者： Qinfeng Yang Guihua liu Guanghao Chen Guo Chen Keyu Chen Lei Fan Yuesheng Tu Jialan Chen Zhanjun Shi Chuan Chen shubo liu Geyang Deng Xiaoqian Deng Chunhan Sun Xiaoyang Li Shuofei Yang Shaowei Zheng Bin Chen Division of Orthopaedics and Traumatology Department of OrthopaedicsNanfang HospitalSouthern Medical UniversityGuangzhouGuangdong510515China Division of Orthopaedic Surgery Department of OrthopaedicsNanfang HospitalSouthern Medical UniversityGuangzhouGuangdong510515China Institute of Orthopaedics Huizhou Central People’s HospitalHuizhouGuangdong516008China Department of Orthopaedics The Second Hospital of JiaxingThe Second Affiliated Hospital of Jiaxing UniversityJiaxingZhejiang314000China Department of Obstetrics and Gynecology Core Facility CenterThe First Affiliated Hospital of USTCDivision of Life Sciences and MedicineUniversity of Science and Technology of ChinaHefeiAnhui230001China State Key Laboratory of Ophthalmology Zhongshan Ophthalmic CenterSun Yat-sen UniversityGuangdong Provincial Key Laboratory of Ophthalmology and Visual ScienceGuangzhouGuangdong510060China Department of Vascular Surgery The Quzhou Affiliated Hospital of Wenzhou Medical UniversityQuzhou People’s HospitalQuzhouZhejiang324000China Department of Vascular Surgery Renji HospitalSchool of MedicineShanghai Jiaotong UniversityShanghai200127China Department of Sports Medicine and Rehabilitation Peking University Shenzhen HospitalShenzhenChina State Key Laboratory of Quality Research in Chinese Medicines Laboratory of Drug Discovery from Natural Resources and IndustrializationSchool of PharmacyMacao University of Science and TechnologyMacao999078China

Hemophilic articular cartilage damage presents a significant challenge for surgeons,characterized by recurrent intraarticular bleeding,a severe inflammatory microenvironment,and limited self-repair capability of cartilage ***,there is a lack of tissue engineering-based integrated therapies that address both early hemostasis,anti-inflammation,and long-lasting chondrogenesis for hemophilic articular cartilage ***,we developed an adhesive hydrogel using oxidized chondroitin sulfate and gelatin,loaded with exosomes derived from bone marrow stem cells(BMSCs)(Hydrogel-Exos).This hydrogel demonstrated favorable injectability,self-healing,biocompatibility,biodegradability,swelling,frictional and mechanical properties,providing a comprehensive approach to treating hemophilic articular cartilage *** adhesive hydrogel,featuring dynamic Schiff base bonds and hydrogen bonds,exhibited excellent wet tissue adhesiveness and hemostatic *** a pig model,the hydrogel could be smoothly injected into the knee joint cartilage defect site and gelled in situ under fluid-irrigated arthroscopic *** in vitro and in vivo experiments confirmed that the sustained release of exosomes yielded anti-inflammatory effects by modulating macrophage M2 polarization through the NF-κB *** immunoregulatory effect,coupled with the extracellular matrix components provided by the adhesive hydrogel,enhanced chondrogenesis,promoted the cartilage repair and joint function restoration after hemophilic articular cartilage *** conclusion,our results highlight the significant application potential of Hydrogel-Exos for early hemostasis,immunoregulation,and long-term chondrogenesis in hemophilic patients with cartilage *** innovative approach is well-suited for application during arthroscopic procedures,offering a promising solution for addressing the complex challenges associated with hemophilic articular cartilage damage.

关键词： Hemophilic articular cartilage defect Adhesive hydrogel Exosomes Anti-inflammation Chondrogenesis