检索结果-南通市图书馆

Efficient identity-based signature over NTRU lattice

在线全文

学校读者我要写书评

暂无评论

Frontiers of Information Technology & Electronic Engineering 2016年第2期17卷 135-142页

作者： Jia XIE Yu-pu hu Jun-tao GAO Wen GAO School of Telecommunications Engineering Xidian University Xi'an 710071 China The State Key Laboratory of Integrated Services Network Xi 'an 710071 China

Identity-based signature has become an important technique for lightweight authentication as soon as it was proposed in ***,identity-based signature schemes based on the integer factorization problem and discrete logarithm problem were proposed one after ***,the rapid development of quantum computers makes them ***,many efforts have been made to construct identity-based signatures over lattice assumptions against attacks in the quantum ***,their efficiency is not very *** this study,an efficient identity-based signature scheme is presented over the number theory research unit(NTRU) lattice *** new scheme is more efficient than other lattice-and identity-based signature *** new scheme proves to be unforgeable against the adaptively chosen message attack in the random oracle model under the hardness of the γ-shortest vector problem on the NTRU lattice.

关键词： Identity Signature Lattice Number theory research unit (NTRU)

Collection efficiency of a monitor parallel plate ionization chamber for pencil beam scanning proton therapy

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2020年第2期31卷 1-10页

作者： Rong-Cheng Han Yong-Jiang Li Yue-hu pu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai APACTRON Particle Equipment Co.Ltd Shanghai 201800China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China

The collection efficiency of monitor parallel plate ionization chambers is the main uncertainty in the beam control of pencil beam scanning *** calculation methods for collection efficiency in photon or passive scattering proton systems have not considered the characteristics of non-uniform charge density in pencil beam scanning *** this study,Boag’s theory was applied to a proton pencil beam scanning *** transverse distribution of charge density in the ionization chamber was considered to be a Gaussian function and an analytical solution was derived to calculate collection efficiency in the beam spot *** calculation method is called the integral method and it was used to investigate the effects of beam parameters on collection *** was determined that collection efficiency is positively correlated with applied voltage,beam size,and beam energy,but negatively correlated with beam current ***,it was confirmed that collection efficiency is improved when the air filling the monitor parallel plate ionization chamber is replaced with nitrogen.

关键词： Collection efficiency Monitor ionization chamber Pencil beam scanning Proton therapy

Physical design and multi-particle simulations of a compact IH-DTL with KONUS beam dynamics for proton therapy

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2020年第7期31卷 12-24页

作者： Jian Qiao Xiu-Cui Xie De-Ming Li Yue-hu pu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of the Chinese Academy of Sciences Beijing 100049China Shanghai APACTRON Particle Equipment Company Ltd. Shanghai 210800China

A compact room-temperature inter-digital H-mode(IH)drift tube linac(DTL)with Kombinierte Null Grad Struktur beam dynamics is proposed in this *** proposed IH-DTL,which operates at 325 MHz,accelerates 18 mA proton particles from 3.0 to 7.0 MeV as part of a proton synchrotron-based therapy *** is composed of two main sections,namely a bunching section(-30°)and accelerating section(0°).There is no transverse focusing element inside the cavity,which increases the acceleration gradient and reduces the cavity length and power *** our physical designs,LORASR code is utilized for beam dynamics design and multi-particle *** synchronous particle energy,injection phase,and acceleration voltage of each gap are optimized carefully to increase transmission efficiency while minimizing beam emittance growth and beam *** total length of the cavity is 0.82 m and the acceleration gradient reaches 4.88 MV/m,resulting in a transmission efficiency of 100%and beam emittance growth less than10%.The details of the specific work undertaken in this study are presented in this paper.

关键词： bunch beam particle

Robust Face Recognition via Low-rank Sparse Representation-based Classification

在线全文

学校读者我要写书评

暂无评论

International Journal of Automation and computing 2015年第6期12卷 579-587页

作者： Hai-Shun Du Qing-pu hu Dian-Feng Qiao Ioannis Pitas Institute of Image Processing and Pattern Recognition Henan University Department of Informatics Aristotle University of Thessaloniki

Face recognition has attracted great interest due to its importance in many real-world applications. In this paper,we present a novel low-rank sparse representation-based classification(LRSRC) method for robust face recognition. Given a set of test samples, LRSRC seeks the lowest-rank and sparsest representation matrix over all training samples. Since low-rank model can reveal the subspace structures of data while sparsity helps to recognize the data class, the obtained test sample representations are both representative and discriminative. Using the representation vector of a test sample, LRSRC classifies the test sample into the class which generates minimal reconstruction error. Experimental results on several face image databases show the effectiveness and robustness of LRSRC in face image recognition.

关键词： Face recognition image classification sparse repre

CCA2 secure biometric identity based encryption with constant-size ciphertext

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science C(Computers and Electronics) 2011年第10期12卷 819-827页

作者： Yang YANG Yu-pu hu Le-you ZHANG Chun-hui SUN Department of Communication Engineering Xidian University Xi'an 710071 China Department of Mathematics and Computer Science Fuzhou University Fuzhou 350002 China Department of Mathematics Science Xidian University Xi'an 710071 China

We propose a new biometric identity based encryption scheme （Bio-IBE）, in which user biometric information is used to generate the public key with a fuzzy extractor. This is the first Bio-IBE scheme that achieves constant size ciphertext. This is also a scheme that is secure against the adaptive chosen ciphertext attack （CCA2）. Details are presented along with a discussion of Shamir＇s threshold secret sharing and fuzzy extraction of biometrics, which is based on error correction codes. We also define a security model and prove that the security of the proposed scheme is reduced to the decisional bilinear Diffie-Hellman proposed scheme has better efficiency and stronger security （DBDH） assumption. The comparison shows that the compared with the available Bio-IBE schemes.

关键词： public key cryptography Identity-based Data security Biometric Encryption

Shortening the delivery time of proton therapy by real-time compensation method with raster scanning

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2022年第6期33卷 62-74页

作者： Xiang-Shang Sun Yong-Jiang Li Jun-Ya Liu Wen-Tao Liao Chao Wu Yue-hu pu Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Beijing 100049China Shanghai APACTRON Particle Equipment Co. LtdShanghai 201800China Shanghai Advanced Research Institute Chinese Academy of SciencesShanghai 201210China Medical Equipment Innovation Research Center West China HospitalSichuan UniversityChengdu 610041China

Among the various scanning techniques, spot and raster scanning are the most frequently adopted. Raster scanning turns off the beam only when each isoenergy slice irradiation is completed. This feature intrinsically solves the leakage dose and frequent beam-switching problems encountered during spot scanning. However, to shorten the delivery time of raster scanning, a sophisticated dose control strategy is required to guarantee dose *** this study, a real-time compensation method with raster scanning for synchrotron systems was designed. It is characterized by a small spot-spacing planning strategy and real-time subtraction of the transient number of particles delivered between two planning-spot positions from the planned number of particles of the subsequent raster *** efficacy of the compensation method was demonstrated by performing accurate raster scanning simulations with an in-house simulation code and accurate final dose evaluations with a commercial treatment planning *** the similar dose evaluation criteria under a practical high scanning speed, compared with the spot scanning method, the total delivery time of the compensated raster scanning method was significantly shortened by 53.3% in the case of irradiating a cubical target and by 28.8% in a pelvic case. Therefore, it can be concluded that real-time compensated raster scanning with a fast scanning configuration can significantly shorten the delivery time compared to that of spot scanning. It is important to reduce the pressure on patients caused by prolonged immobilization and to improve patient throughput capacity at particle therapy centers.

关键词： Proton therapy Raster scanning Delivery time Scanning simulation

An insight into failure mechanism of NASICON-structured Na3V2（PO4）3 in hybrid aqueous rechargeable battery

在线全文

学校读者我要写书评

暂无评论

Journal of Energy Chemistry 2019年第5期28卷 1-7页

作者： Xinxin Zhang Jun Ma pu hu Bingbing Chen Chenglong Lu Xinhong Zhou Pengxian Han Lihua Chen Guanglei Cui College of Chemistry and Molecular Engineering Qingdao University of Science & TechnologyQingdao 266042ShandongChina Qingdao Industrial Energy Storage Research Institute Qingdao Institute of Bioenergy and Bioprocess TechnologyChinese Academy of SciencesQingdao 266101ShandongChina Department of Mechanical & Areospace Engineering University of FloridaGainesville 32611FLUSA

NASICON (Na-super-ionic-conductors)-structured materials have attracted extensive research interest due to their great application potential in secondary batteries. However, the mechanism of capacity fading for NASICON-structured electrode materials has been rarely studied. In this paper, we synthesized the NASICON-structured Na3V2(PO4)3/C composite by simple sol-gel and high-temperature solid-phase method and investigated its electrochemical performance in Na-Zn hybrid aqueous rechargeable batteries. After characterizing the structure, morphology and composition variations as well as the interfacial resistance changes of Na3V2(PO4)3/C cathode during cycling, we propose a mechanical and interfacial degradation mechanism for capacity fading of NASICON-structured Na3V2(PO4)3/C in Na-Zn hybrid aqueous rechargeable batteries. This work will shed light on enhancing the mechanical and in terfacial stability of NASICON-structured Na3V2(PO4)3/C in Na-Zn hybrid aqueous rechargeable batteries.

关键词： Mechanical degradation Na3V2(PO4)3 Zn metal anode Hybrid aqueous battery Failure mechanism

RF design and study of a 325 MHz 7 Me V APF IH-DTL for an injector of a proton medical accelerator

在线全文

学校读者我要写书评

暂无评论

Nuclear Science and Techniques 2019年第9期30卷 34-46页

作者： Xuan Li Yue-hu pu Fan Yang Xiu-Cui Xie Qiang Gu Jian Qiao Ming-hua Zhao Shanghai Advanced Research Institute Chinese Academy of Sciences Shanghai 201210 China Shanghai Institute of Applied Physics Chinese Academy of Sciences Shanghai 201800 China University of Chinese Academy of Sciences Beijing 100049 China Shanghai APACTRON Particle Equipment Co. Ltd Shanghai 201800 China

A compact interdigital H-mode drift-tube linac (IH-DTL) with the alternating-phase-focusing (APF) method, working at 325 MHz was designed for an injector of a proton medical accelerator. When fed in with a proper RF (radio frequency) power, the DTL cavity could establish the corresponding electromagnetic field to accelerate the ‘‘proton bunches’’ from an input energy of 3 MeV to an output energy of 7 MeV successfully, without any additional radial focusing elements. The gap-voltage distribution which was obtained from the CST■ Microwave Studio software simulations of the axial electric field was compared with that from the beam dynamics, and the errors met the requirements within ± 5%. In this paper, the RF design procedure and key results of the APF IH-DTL, which include the main RF characteristics of the cavity, frequency sensitivities of the tuners, and coupling factor of the RF power input coupler are presented.

关键词： Proton therapy Proton medical accelerator Injector Drift-tube linac (DTL) Interdigital H-mode (IH) Alternating-phase-focusing (APF)

Highly efficient synthesis of boron nitride nanotubes by catalytic chemical vapor deposition of boron/nickel containing precursors

在线全文

学校读者我要写书评

暂无评论

Journal of Materiomics 2022年第6期8卷 1199-1204页

作者： Heng Wang Haoran Yang Yongzhi Peng Yulin Zheng Dongying huang pu hu Yawei Li Zhengyi Fu hubei Key Laboratory of Plasma Chemistry and Advanced Materials Key Laboratory of Green Chemical Engineering Process of Ministry of EducationWuhan Institute of TechnologyWuhan430205China State Key Laboratory of Advanced Technology for Materials Synthesis and Processing Wuhan University of TechnologyWuhan430070China The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan430081China

High-purity and high-yield boron nitride nanotubes with large aspect ratio were prepared by a facile two-step process,including the synthesis of boron/nickel containing precursors by precipitation reactions and subsequent thermally catalytic chemical vapor deposition *** influence of catalyst content and annealing temperature on the phase composition and microstructure of the products were *** results show that it is difficult to exert the catalytic effect of nickel-based catalyst at low temperatures(<1400℃).At appropriate temperatures(1400-1500℃),highly crystalline boron nitride nanotubes with a length of more than 50 mm and a diameter of 50 nm are *** content of catalyst in the precursor mainly affects the morphology of the boron nitride *** the content is too low,it is easy to form boron nitride particles;while high catalyst content can easily lead to catalyst aggregation and form a submicron one-dimensional boron nitride with unregular *** on microstructural evolutions,phase changes,and thermodynamic analysis,the vapor-liquid-solid(V-L-S)growth mechanism of the tip growth mode dominates the formation of boron nitride nanotubes has also been verified.

关键词： Boron nitride nanotubes Highly efficient synthesis Boron/nickel containing precursors Growth mechanism