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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

A modified interval subdividing based geometric calibration method for interior tomography

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Chinese Physics B 2014年第9期23卷 571-577页

作者：张峰闫镔李磊席晓琦江桦 National Digital Switching system engineering & Technology research center

The interior tomography is commonly met in practice, whereas the self-calibration method for geometric parameters remains far from explored. To determine the geometry of interior tomography, a modified interval subdividing based method, which was originally developed by Tan et al.,^[11] was presented in this paper. For the self-calibration method, it is necessary to obtain the reconstructed image with only geometric artifacts. Therefore, truncation artifacts reduction is a key problem for the self-calibration method of an interior tomography. In the method, an interior reconstruction algorithm instead of the Feldkamp-Davis-Kress （FDK） algorithm was employed for truncation artifact reduction. Moreover, the concept of a minimum interval was defined as the stop criterion of subdividing to ensure the geometric parameters are determined nicely. The results of numerical simulation demonstrated that our method could provide a solution to the self- calibration for interior tomography while the original interval subdividing based method could not. Furthermore, real data experiment results showed that our method could significantly suppress geometric artifacts and obtain high quality images for interior tomography with less imaging cost and faster speed compared with the traditional geometric calibration method with a dedicated calibration phantom.

关键词： interior tomography geometric calibration interval subdividing minimum interval

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

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

Mechanical response of transmission lines based on sliding cable element

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Journal of Central South University 2014年第8期21卷 3370-3377页

作者：刘云钱振东夏开全 College of Civil and Transportation engineering Hohai University intelligent Transportation system research center Southeast University China Electric Power research Institute

In order to study the sliding characteristics when the cable is connected with the other rods in the transmission line structures,a linear sliding cable element based on updated Lagrangian formulation and a sliding catenary element considering the out-of-plane stiffness coefficient are put forward.A two-span and a three-span cable structures are taken as examples to verify the sliding cable *** comparing the tensions of the two proposed cable elements with the existing research results,the error is less than 1%,which proves the correctness of the proposed *** sliding characteristics should be considered in the practical engineering because of the significant difference between the tensions of sliding cable elements and those of cable element without considering *** out-of-plane stiffness coefficient and friction characteristics do not obviously affect the cable tensions.

关键词： transmission lines sliding cable element updated Lagrangian formulation geometric nonlinearity mechanical response

An Efficient Gait-generating Method for Electrical Quadruped Robot Based on Humanoid Power Planning Approach

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Journal of Bionic engineering 2021年第6期18卷 1463-1474页

作者： Lelai Zhou Tianfa Li Zaiyang Liu Yibin Li School of Control Science and engineering Center for RoboticsShandong UniversityJinan250061China engineering research center of intelligent Unmanned system Ministry of EducationJinan250061China

The research field of legged robots has always relied on the bionic robotic research,especially in locomotion regulating approaches,such as foot trajectory planning,body stability regulating and energy efficiency *** energy consumption and keeping the stability of body are considered as two main characteristics of human *** work devotes to develop an energy-efficient gait control method for electrical quadruped robots with the inspiration of human walking *** on the mechanical power distribution trend,an efficient humanoid power redistribution approach is established for the electrical quadruped *** studying the walking behavior acted by mankind,such as the foot trajectory and change of mechanical power,we believe that the proposed controller which includes the bionic foot movement trajectory and humanoid power redistribution method can be implemented on the electrical quadruped robot *** stability and energy efficiency of the proposed controller are tested by the simulation and the single-leg prototype *** results verify that the humanoid power planning approach can improve the energy efficiency of the electrical quadruped robots.

关键词： Bionic robot Mechanical power Bionic trajectory Quadruped robot

Phase-sensitive manipulation of squeezed state by a degenerate optical parametric amplifier inside coupled optical resonators

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Optoelectronics Letters 2022年第3期18卷 135-142页

作者： DI Ke WANG Wenbo CUI Wei GUO Junqi LIU Yu DU Jiajia Chongqing engineering research center of intelligent sensing Technology and Microsystem Chongqing University of Post and TelecommunicationsChongqing 400065China

In this paper, we investigate the quantum fluctuations of subharmonic reflected field from a triple-resonant degenerate optical parametric amplifier(OPA) inside coupled optical resonators, which is driven by the squeezed beam at signal frequency. By controlling the relative phase between the pump beam and the injected signal beam, we can see the quantum fluctuation in the phase direction and amplitude direction due to the parametric down-conversion process in the cavity. Thus, the phase sensitive operation of the compression field is realized due to the quantum interference between the harmonic field of the down converter of OPA and the inner field of the coupled optical resonator. We verified the quantum coherent phenomena of OPA in coupled optical resonators and phase-sensitive manipulations of quantum entanglement for quantum information processing. We realized the electromagnetically induced transparency-like(EIT-like) effect and the optical parameter conversion process at the same time in one optical device. These properties can favor higher manipulation precision and control efficiency, which is more suitable for the integration of quantum-on-chip systems, laying a foundation for the practical application of quantum information.

关键词： quantum parametric degenerate

Design and characteristic research on side-polished fiber fluid sensing system

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Optoelectronics Letters 2021年第8期17卷 490-495页

作者： LIU Yu YANG Qingrong LU Yongle DI Ke WEN Dandan YUE Yiting ZHOU Min WANG Changle GUO Junqi Chongqing engineering research center of intelligent sensing Technology and Microsystem Chongqing University of Posts and TelecommunicationsChongqing 400065China

A novel fluid sensing system based on side-polished optical fiber(SPOF)is proposed,which realizes the fluid replaceability and effective refractive index(RI)sensing *** investigations demonstrate that the photonic bandgap effect can be obtained if the RI of liquid is higher than that of substrate material in the wavelength range *** relationship between bandgap edge wavelength and RI is studied *** SPOF with a depth of 57μm is used in the experiment to realize the construction of the fluid *** filling three different liquids,the result shows that the wavelength of the bandgap edge has a red shift with RI increased,which is nearly linear in the RI range of 1.56—1.6 with a sensitivity about 5543.64 nm/*** proposed sensing system can be flexibly applied to the field of fluid characteristic sensing such as biochemical solution characteristic detections.

关键词： fiber bandgap characteristic

High sensitivity dual polarization four channels surface plasmon resonance refractive index sensor with wide detection range and high linearity based on photonic crystal fiber

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Optoelectronics Letters 2025年

作者： CUI Nan PAN Honggang ZHANG Ailing ZHAO Zihong CHEN Zhipan ZHANG Bo Tianjin Key Laboratory of Film Electronic and Communication Devices， engineering research center of Optoelectronic Devices and Communication Technology， Ministry of Education， School of Integrated Circuit Science and engineering， Tianjin University of Technology

In this paper， we propose and numerically characterize the optical characteristics of a high sensitivity dual polarization four channels surface plasmon resonance refractive index sensor with wide detection range and high linearity based on photonic crystal fiber （PCF）. Four light transmission channels are constructed by using big air holes. The small rectangular air hole in the center of the fiber core is used to add asymmetry. We use gold plasma material to achieve better sensing performance. A thin film of TiO2is placed on the PCF surface， which assists gold in the adhesion on PCF. The maximum wavelength sensitivity of the sensor can reach 20000 nm/RIU in both x and y polarization modes. While the maximum wavelength resolution of the sensor is 5×10-6RIU. The average wavelength sensitivity reached 15900nm/RIU and 15800nm/RIU in x and y polarization mode. The sensor features R2=0.9969 / R2=0.9966 high linear performance in x and y polarization mode and the maximum FOM values 509.13 RIU-1/ 489.63 RIU-1in x and y polarization mode. Besides the sensor’s detection range is 1.26-1.36， which is a wide refractive index detection range. The sensor has a wide range of applications in biomedical and other fields.

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