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Virtual network function scheduling via multilayer encoding genetic algorithm with distributed bandwidth allocation

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Science China(Information Sciences) 2018年第9期61卷 93-111页

作者： Quan YUAN Hongbo TANG Wei YOU Xiaolei WANG Yu ZHAO National Digital Switching System Engineering and technological Research center

Network function virtualization represents a revolutionary approach to network service deployment. This software-oriented approach for virtual network functions(VNFs) deployment enables more flexible and dynamic network services to meet diversified demands. To minimize the execution time of all VNFs in service function chains, VNF scheduling must be addressed. In this paper, we improve upon the flexible job-shop model by introducing the process of bandwidth allocation. First, we propose a multilayer encoding genetic algorithm to solve the VNF scheduling model. In addition, we design a distributed method for bandwidth allocation based on the Nash bargaining solution. Finally, by combining the genetic algorithm with distributed bandwidth allocation, we present a heuristic algorithm that solves the VNF scheduling problem in one stage. Using a multilayer encoding genetic algorithm, we simplify the constraints of the VNF scheduling problem and reduce its time complexity. At the same time, our Nash game solution refines the granularity of bandwidth allocation to further reduce the transmission delay between VNFs. The effectiveness of our proposed heuristic algorithm is verified through numerical evaluation. Compared with existing approaches,our method exhibits shorter scheduling time and reduces CPU time by 45% in simulated scenarios.

关键词： network function virtualization virtual network function scheduling genetic algorithm bandwidth allocation convex optimization

Image reconstruction based on total-variation minimization and alternating direction method in linear scan computed tomography

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Chinese Physics B 2013年第7期22卷 582-589页

作者：张瀚铭王林元闫镔李磊席晓琦陆利忠 National Digital Switching System Engineering and technological Research center

Linear scan computed tomography （LCT） is of great benefit to online industrial scanning and security inspection due to its characteristics of straight-line source trajectory and high scanning speed. However, in practical applications of LCT, there are challenges to image reconstruction due to limited-angle and insufficient data. In this paper, a new reconstruction algorithm based on total-variation （TV） minimization is developed to reconstruct images from limited-angle and insufficient data in LCT. The main idea of our approach is to reformulate a TV problem as a linear equality constrained problem where the objective function is separable, and then minimize its augmented Lagrangian function by using alternating direction method （ADM） to solve subproblems. The proposed method is robust and efficient in the task of reconstruction by showing the convergence of ADM. The numerical simulations and real data reconstructions show that the proposed reconstruction method brings reasonable performance and outperforms some previous ones when applied to an LCT imaging problem.

关键词： linear scan CT image reconstruction total variation alternating direction method

Parallel Algorithm Core: A Novel IPSec Algorithm Engine for Both Exploiting Parallelism and Improving Scalability

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Journal of Computer Science & Technology 2008年第5期23卷 792-805页

作者：程东年胡宇翔刘彩霞 National Digital Switching System Engineering & technological Research center

To deal with the challenges of both computation-complexity and algorithm-scalability posed to the design of an IPSec engine, we develop PAC （parallel algorithm core）, called PAC, employed in an IPSec engine, which can meet requirements of both exploiting parallelism existing in IPSec packets and offering scalability in both the scales and types of cryptographic algorithms. With three kinds of parallelism and two kinds of transparency defined, a novel hierarchy of the specifically-designed parallel structure for PAC is presented, followed by corresponding mechanisms. With a simulation, the scalability of PAC is examined. For the purpose of performance evaluation, a Quasi Birth-and-Death （QBD） process is then established to model a simplified version of the proposed PAC. Performance evaluation of PAC in terms of two representative measures, throughput and mean packet waiting time, is numerically investigated. A comparison study is done on a simulation basis. Conclusions are finally drawn for providing a helpful guideline for both the design and implementation of our proposal.

关键词： computer network architecture IPSec queuing theory parallel processing numerical analysis

A New Distinguishing Attack on Grain-V1 with 111 Initialization Rounds

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Journal of Systems Science & Complexity 2019年第3期32卷 970-984页

作者： MA Zhen TIAN Tian QI Wenfeng National Digital Switching System Engineering & technological Research center

The Grain-v1 stream cipher has been selected in the eSTREAM hardware finalists. In this paper, the authors derive a new distinguishing attack on Grain-v1 with 111 initialization rounds in a single-key setting. To achieve this goal, the authors present two delicate strategies targeting an obvious distinguishing probability of the output difference of reduced Grain-v1. The authors show that conditional differential cryptanalysis of reduced Grain-v1 with 111 initialization rounds could mount a distinguishing attack with success probability about 0.8281 for all secret keys. It is also shown that when the attacking round further increases to 112 and 113, the distributions of the output differences are nearly random. Thus far, to the best of the authors' knowledge, the attack on Grain-v1 with 111 initialization rounds is the best single-key cryptanalytic result for reduced versions of Grain-vl in terms of the number of attacking rounds.

关键词： Cryptanalysis differential cryptanalysis distinguishing attack Grain-v1 stream cipher

New Insights into Divide-and-Conquer Attacks on the Round-Reduced Keccak-MAC

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Chinese Journal of Electronics 2019年第4期28卷 698-705页

作者： YE Chendong TIAN Tian National Digital Switching System Engineering and technological Research center

Keccak is the final winner of SHA-3 competition and it can be used as message authentic codes as well. The basic and balanced divide-and-conquer attacks on Keccak-MAC were proposed by Dinur et *** Eurocrypt 2015. The idea of cube attacks is used in the two attacks to divide key bits into small portions. By carefully analysing the mappings used in Keccak-MAC, it is found that some cube variables could divide key bits into smaller portions and so better divide-and-conquer attacks are obtained. In order to evaluate the resistance of Keccak-MAC against divide-and-conquer attacks based on cubes, we theoretically analyse the lower bounds of the complexities of divide-and-conquer attacks. It is shown that the lower bounds of the complexities are still not better than those of the conditional cube tester proposed by Senyang Huang et al.. This indicates that KeccakMAC can resist the divide-and-conquer attack better than the conditional cube tester. We hope that these techniques still could provide some new insights on the future cryptanalysis of Keccak.

关键词： Keccak-MAC Divide-and-conquer attacks Cube attacks

Performance Analysis of Hybrid Distribution in Human-Centric Multimedia Networking

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Chinese Journal of Electronics 2016年第4期25卷 761-767页

作者： HU Yuxiang DONG Fang LAN Julong National Digital Switching System Engineering and technological Research center

With the booming of Human-centric multimedia networking(HMN),there are rising amount of human-made multimedia that needs to distribute to consumers with higher speed and *** distribution of Client/Server(C/S) and Peer-to-Peer(P2P) have been successfully deployed on the Internet and the practical benefits have been widely reported,while its theoretical performance remains unknown for mass data delivery *** paper presents an analytical and experimental study on the performance of accelerating large-scale hybrid distribution over the *** particular,this paper focuses on the user behavior in HMN and establishes a user behavior model based on the Kermack-McK endrick model in *** expressions of average delay in HMN are then derived based on C/S,P2 P and hybrid distribution,*** simulation shows how to design and deploy a hybrid distribution system of HMN that helps to bridge the gap between system ultilization and quality of service,which provides direct guidance for practical system design.

关键词： Hybrid distribution Peer-to-peer Client/server Behaviour model Performance analysis

Differential Fault Attack on the Stream Cipher LIZARD

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Chinese Journal of Electronics 2021年第3期30卷 534-541页

作者： MA Zhen TIAN Tian QI Wenfeng National Digital Switching System Engineering technological Research center

In this paper, we try to give a security evaluation of LIZARD stream cipher in regard to fault attacks, which, to the best of our knowledge, is the first fault analysis on LIZARD. We design a differential engine of LIZARD to track the differential trail of the keystreams. It is shown that the distributions of the keystream differences are heavily biased. Utilizing this characteristic, we propose an improved method to identify the fault location for LIZARD whose success probability approaches 1. Then we use the fault-free keystream and faulty keystreams to generate system of equations in internal state variables and solve it by SAT solver. The result shows that with 100 keystream bits, only 6 different faults are needed to recover the internal state. Finally,the comparison between LIZARD and Grain v1 shows that LIZARD is more resistable than Grain v1 in regard to fault attacks.

关键词： cryptography fault tolerant computing probability keystream differences faulty keystreams differential fault attack LIZARD stream cipher fault attacks fault analysis differential trail fault-free keystream fault location differential engine stream cipher LIZARD

Yield of alarm features in predicting significant endoscopic findings among hospitalized patients with dyspepsia

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World Journal of Gastroenterology 2024年第26期30卷 3210-3220页

作者： Lama Ibrahim Maamoun Basheer Tawfik Khoury Wisam Sbeit Department of Internal Medicine Galilee Medical CenterNahariya 22001Israel Department of Gastroenterology Galilee Medical CenterNahariya 22001Israel Azrieli Faculty of Medicine Bar-Ilan UniversitySafed 1311502Israel

BACKGROUND Dyspepsia is a very prevalent upper gastrointestinal tract symptoms *** of these symptoms might arise from serious underlying diseases,so the promotion of evidence-based guidelines could potentially better align evaluation and *** To determine the value of alarm features as a predictive factor for significant endoscopic findings(SEFs)among hospitalized patients presenting with *** We conducted a retrospective case-control study including information about 6208 endoscopic procedures performed for hospitalized *** were divided into two groups,with and without SEFs,and compared to elucidate the ability of the different alarm features to predict *** During the study,605 patients fulfilled the inclusion *** the demographics and clinical characteristics of the two groups were compared,tachycardia(P<0.05),normocytic anemia,(P<0.05),leukocytosis(P<0.05),and hypoalbuminemia(P<0.05)documented on admission prior to endoscopy were strong predictors of *** the alarm features,upper gastrointestinal bleeding,persistent vomiting,odynophagia[odds ratio(OR)=3.81,P<0.05;OR=1.75,P=0.03;and OR=7.81,P=0.07,respectively]were associated with *** weight loss was strongly associated with malignancy as an endoscopic finding(OR=2.05;P<0.05).In addition,long-term use of anti-aggregate medications other than aspirin(P<0.05)was correlated to *** Novel predictors of SEFs were elucidated in this *** parameters could be used as an adjunctive in decision making regarding performing upper endoscopy in hospitalized patients with dyspepsia.

关键词： Dyspepsia Endoscopy Weight loss Anti-aggregate medications Persistent vomiting Odynophagia

Deciphering Water Oxidation Catalysts:The Dominant Role of Surface Chemistry over Reconstruction Degree in Activity Promotion

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Nano-Micro Letters 2025年第3期17卷 340-354页

作者： Li An Jianyi Li Yuanmiao Sun Jiamin Zhu Justin Zhu Yeow Seow Hong Zhang Nan Zhang Pinxian Xi * Zhichuan JXu Chun‑Hua Yan State Key Laboratory of Applied Organic Chemistry Key Laboratory of Nonferrous Metal Chemistry and Resources Utilization of Gansu ProvinceFrontiers Science Center for Rare IsotopesCollege of Chemistry and Chemical EngineeringLanzhou UniversityLanzhou 730000People’s Republic of China School of Materials Science and Engineering Nanyang Technological UniversitySingapore 639798Singapore Faculty of Materials Science and Energy Engineering Institute of Technology for Carbon NeutralityShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen 518055People’s Republic of China Key Laboratory of Electromagnetic Materials and Devices National Center for International Research On Photoelectric and Energy MaterialsSchool of Materials and EnergyElectron Microscopy CenterYunnan UniversityKunming 650091People’s Republic of China State Key Laboratory of Baiyunobo Rare Earth Resource Researches and Comprehensive Utilization Baotou Research Institute of Rare EarthsBaotou 014030People’s Republic of China Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU‑HKU Joint Laboratory in Rare Earth Materials and Bioinorganic ChemistryPeking UniversityBeijing 100871People’s Republic of China

Water splitting hinges crucially on the availability of electrocatalysts for the oxygen evolution *** surface reconstruction has been widely observed in perovskite catalysts,and the reconstruction degree has been often correlated with the activity ***,a systematic study on the roles of Fe substitution in activation of perovskite LaNiO_(3)is *** substituting Fe content influences both current change tendency and surface reconstruction ***_(0.9)Fe_(0.1)O_(3)is found exhibiting a volcano-peak intrinsic activity in both pristine and reconstructed among all substituted perovskites in the LaNi_(1-x)Fe_(x)O_(3)(x=0.00,0.10,0.25,0.50,0.75,1.00)*** reconstructed LaNi_(0.9)Fe_(0.1)O_(3)shows a higher intrinsic activity than most reported NiFe-based ***,density functional theory calculations reveal that Fe substitution can lower the O 2p level,which thus stabilize lattice oxygen in LaNi0.9Fe0.1O3 and ensure its long-term ***,it is vital interesting that activity of the reconstructed catalysts relied more on the surface chemistry rather than the reconstruction *** effect of Fe on the degree of surface reconstruction of the perovskite is decoupled from that on its activity enhancement after surface *** finding showcases the importance to customize the surface chemistry of reconstructed catalysts for water oxidation.

关键词： Oxygen evolution reaction Perovskite oxides Doping Activation and reconstruction