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Joint partial computation offloading and resource allocation in MEC-enable networks

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The Journal of China Universities of Posts and Telecommunications 2023年第1期30卷 80-86页

作者： Wu Hongxin Lin Zhijian chen pingping chen Feng College of Physics and Information Engineering Fuzhou UniversityFuzhou 350108China

The sudden surge of various applications poses great challenges to the computation capability of mobile *** address this issue,computation offloading to multi-access edge computing(MEC)was proposed as a promising *** paper studies partial computation offloading scenario by considering time delay and energy consumption,where the task can be splitted into several blocks and computed both in local devices and MEC,*** the formulated problem is a nonconvex problem,this paper proposes an ant colony-based algorithm to achieve the suboptimal ***,the proposed method first establish a multi-user one-MEC scenario,in which user devices are able to offload some part of the task to MEC ***,it develops an ant colony-based algorithm to decide the offloading parts and allocation strategy of MEC resources to minimize system ***,simulation results show the effectiveness of the proposed algorithm in terms of system cost and demonstrate that it outperforms other existing methods.

关键词： mobile edge computing resource allocation partial computation offloading ant colony-based algorithm

SR-DCSK Cooperative Communication System with Code Index Modulation:A New Design for 6G New Radios

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China Communications 2023年第10期20卷 1-16页

作者： Yi Fang Wang chen pingping chen Yiwei Tao Mohsen Guizani School of Information Engineering Guangdong University of TechnologyGuangzhou 510006China School of Advanced Manufacturing Fuzhou UniversityJinjiang campus362251China Department of Machine Learning MBZUAIAbu Dhabi999041UAE

This paper proposes a high-throughput short reference differential chaos shift keying cooperative communication system with the aid of code index modulation,referred to as CIM-SR-DCSK-CC *** the proposed CIM-SR-DCSK-CC system,the source transmits information bits to both the relay and destination in the first time slot,while the relay not only forwards the source information bits but also sends new information bits to the destination in the second time *** be specific,the relay employs an N-order Walsh code to carry additional log_(2)N information bits,which are superimposed onto the SRDCSK signal carrying the decoded source information ***,the superimposed signal carrying both the source and relay information bits is transmitted to the ***,the theoretical bit error rate(BER)expressions of the proposed CIMSR-DCSK-CC system are derived over additive white Gaussian noise(AWGN)and multipath Rayleigh fading *** with the conventional DCSKCC system and SR-DCSK-CC system,the proposed CIM-SR-DCSK-CC system can significantly improve the throughput without deteriorating any BER *** a consequence,the proposed system is very promising for the applications of the 6G-enabled lowpower and high-rate communication.

关键词： differential chaos shift keying cooperative communication short reference code index modulation high throughput bit error rate

Angular velocity estimation using characteristics of star trails obtained by star sensor for spacecraft

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Science China(Information Sciences) 2021年第1期64卷 201-214页

作者： Xiaolin NING pingping chen Yueqing HUANG Weiren WU Jiancheng FANG School of Instrumentation Science & Opto-electronics Engineering Beihang University Lunar Exploration and Space Program Center China National Space Administration

Many studies have been conducted about angular velocity estimation using star sensors, and fairly good performance is achieved when the spacecraft is working at low-dynamic environments. However,when the spacecraft rotates at a large angular velocity, the star image will become blurred, which makes it difficult to identify and recognize star centroids, which, in turn, reduces the accuracy of angular velocity estimation. Therefore, to solve the problem with angular velocity estimation in highly dynamic situations,this research studies a method of angular velocity estimation using blurred star images. The length and ending point coordinates of star trails obtained from these blurred star images are used for a series of processes, which includes the pre-processing of blurred star images, determination of starting and ending points, thinning and selection of star trails, and calculation of trail lengths. Simulations show that the effectiveness of the proposed method in highly dynamic situations and the angular velocity estimation errors in constant and sinusoidal variation are reduced by at least 66% and 62%, respectively, compared with those of the traditional method.

关键词： angular velocity estimation star sensor blurred star images star trail characteristics unscented Kalman filter

Study on Mechanical Properties and Action Mechanism of Leather Industrial Sludge Aggregate Baking-Free Bricks

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Journal of Renewable Materials 2023年第1期11卷 453-471页

作者： Lei Guo Zekun Wang Lixia Guo pingping chen School of Water Conservancy North China University of Water Resources and Electric PowerZhengzhou450046China Henan Water Valley Research Institute Zhengzhou450046China Henan Key Laboratory of Water Environment Simulation and Treatment Zhengzhou450002China

Taking an industrial sludge and its preparation of sludge wrap shell aggregates(WSAs)instead of sand to prepare baking-free brick as the research object,the development law of mechanical properties and the influence mechanism of macro and micro characteristic parameters of the bricks under different sludge and WSAs replacement rates were studied through the macroscopic mechanical properties test,with the help of nuclear magnetic resonance(NMR),transmission electron microscopy-energy spectrum and other testing technology and pores and cracks analysis system(PCAS)*** results showed that the compressive strength of each sample decreased with the increase of sludge *** the sludge content was less than 30%,it was mainly affected by the water-binder *** the sludge content was more than 30%,it was mainly affected by the sludge *** the age of 7 days,with the increase in replacement rate of WSAs,the compressive strength of the S10 and S30 groups was higher than that of the control *** compressive strength of the S50 experimental group was 30.38 MPa,and the loss of compressive strength was slight compared with the control *** water absorption rate of the 28 days S100 experimental group increased by 10.71%compared with the control *** the content of WSAs was less than 50%,the holes above 0.1μm in the brick can be reduced and transformed into smaller holes,with a decreasing trend of the plane porosity of the *** microscopic results of the baking-free brick showed that the three-phase system of WSAs-interface transition area-mortar was poorly bonded and delaminated compared with the gravel aggregate-interface transition area-mortar system,and damage was more likely to occur in the WSAs and interface transition *** above results show that it is feasible to use sludge and WSAs instead of sand for the preparation of baking-free *** technology not only solves the problem of sludge disposal,but also protects the ov

关键词： Sludge wrap shell aggregates baking-free brick interface

Influence of coupled boundary layer suction and bowed blade on flow field and performance of a diffusion cascade

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Chinese Journal of Aeronautics 2017年第1期30卷 249-263页

作者： Cao Zhiyuan Liu Bo Zhang Ting Yang Xiqiong chen pingping College of Engineering Peking University School of Power and Energy Northwestern Polytechnical University AECC Xi’an Aero-engine Controls Co. LTD

Based on the investigation of mid-span local boundary layer suction and positive bowed cascade, a coupled local tailored boundary layer suction and positive bowed blade method is developed to improve the performance of a highly loaded diffusion cascade with less suction slot. The effectiveness of the coupled method under different inlet boundary layers is also *** show that mid-span local boundary layer suction can effectively remove trailing edge separation, but deteriorate the flow fields near the endwall. The positive bowed cascade is beneficial for reducing open corner separation, but is detrimental to mid-span flow fields. The coupled method can further improve the performance and flow field of the cascade. The mid-span trailing edge separation and open corner separation are eliminated. Compared with linear cascade with suction, the coupled method reduces overall loss of the cascade by 31.4% at most. The mid-span loss of the cascade decreases as the suction coefficient increases, but increases as bow angle increases. The endwall loss increases as the suction coefficient increases. By contrast, the endwall loss decreases significantly as the bow angle increases. The endwall loss of coupled controlled cascade is higher than that of bowed cascade with the same bow angle because of the spanwise inverse ‘‘C＂ shaped static pressure distribution. Under different inlet boundary layer conditions, the coupled method can also improve the cascade effectively.

关键词： Axial compressor Boundary layer suction Bowed blade Corner separation Coupled method Passage vortex

Tip-leakage flow loss reduction in a two-stage turbine using axisymmetric-casing contouring

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Chinese Journal of Aeronautics 2014年第5期27卷 1111-1121页

作者： Wei Zuojun Qiao Weiyang Shi Peijie chen pingping Zhao Lei School of Power and Energy Northwestern Polytechnical University Institute of Propulsion Technology German Aerospace Center

In order to reduce the losses caused by tip-leakage flow, axisymmetric contouring is applied to the casing of a two-stage unshrouded high pressure turbine（HPT） of aero-engine in this paper. This investigation focuses on the effects of contoured axisymmetric-casing on the blade tipleakage flow. While the size of tip clearance remains the same as the original design, the rotor casing and the blade tip are obtained with the same contoured arc shape. Numerical calculation results show that a promotion of 0.14% to the overall efficiency is achieved. Detailed analysis indicates that it reduces the entropy generation rate caused by the complex vortex structure in the rotor tip region, especially in the tip-leakage vortex. The low velocity region in the leading edge（LE） part of the tip gap is enlarged and the pressure side/tip junction separation bubble extends much further away from the leading edge in the clearance. So the blocking effect of pressure side/tip junction separation bubble on clearance flow prevents more flow on the tip pressure side from leaking to the suction side, which results in weaker leakage vortex and less associated losses.

关键词： Axisymmetric-casing contouring Leakage Leakage flow Loss reduction Tip clearance Turbines

Design of high parallel CNN accelerator based on FPGA for AIoT

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The Journal of China Universities of Posts and Telecommunications 2022年第5期29卷 1-9,61页

作者： Lin Zhijian Gao Xuewei chen Xiaopei Zhu Zhipeng Du Xiaoyong chen pingping School of Advanced Manufacturing Fuzhou UniversityQuanzhou 362251China College of Physics and Information Engineering Fuzhou UniversityFuzhou 350108China

To tackle the challenge of applying convolutional neural network(CNN)in field-programmable gate array(FPGA)due to its computational complexity,a high-performance CNN hardware accelerator based on Verilog hardware description language was designed,which utilizes a pipeline architecture with three parallel dimensions including input channels,output channels,and convolution ***,two multiply-and-accumulate(MAC)operations were packed into one digital signal processing(DSP)block of FPGA to double the computation rate of the CNN ***,strategies of feature map block partitioning and special memory arrangement were proposed to optimize the total amount of off-chip access memory and reduce the pressure on FPGA ***,an efficient computational array combining multiplicative-additive tree and Winograd fast convolution algorithm was designed to balance hardware resource consumption and computational *** high parallel CNN accelerator was deployed in ZU3 EG of Alinx,using the YOLOv3-tiny algorithm as the test *** average computing performance of the CNN accelerator is 127.5 giga operations per second(GOPS).The experimental results show that the hardware architecture effectively improves the computational power of CNN and provides better performance compared with other existing schemes in terms of power consumption and the efficiency of DSPs and block random access memory(BRAMs).

关键词： artificial intelligence of things(AIoT) convolutional neural network(CNN)accelerator Winograd convolution field-programmable gate array(FPGA)

Effect of Huanglianjiedu Tang on fever in rats induced by 2, 4-dinitrophenol

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Journal of Traditional Chinese Medicine 2013年第4期33卷 492-499页

作者： Shumin Liu Na Wang pingping chen Xuzhao Li Changfeng Liu Institute of Traditional Chinese Medicine Heilongjiang University of Chinese Medicine

OBJECTIVE: To study metabolic characteristics of fever in rats induced by 2, 4-dinitrophenol (DNP) and the effect of Huanglianjiedu Tang (HLJDT) on the fever. METHODS: The urine samples were analyzed by ultra-performance liquid chromatography/electrospray ionization quadruple time-of-flight mass spectrometry (UPLC/ESI-Q-TOF-MS) at the positive ion mode scanning, and experimental data were analyzed by the principal component analysis. RESULTS: Eight potential biomarkers indicating the occurrence and evolvement of fever were determined according to ions in urine samples. Five of them were found increased, while the other three decreased. After HLJDD intervention, the increased five were reduced significantly in high dose group, compared with model group, while the decreased three had no obvious change. Five of the eight biomakers were identified with formyl-5-hy-droxykynurenamine, gentisic acid, aminoadipic acid, phenylacetic acid, L-phenylalanyl-L-hydroxyproline on the basis of MS/*** biomarkers are associated with the metabolism of 5-hydroxytryptamine, tyrosine, lysine, phenylalanine and collagen protein, respectively. CONCLUSION: HLJDT had significant effect on DNP-induced fever in rats. The effect was performed possibly by acting on 5-hydroxytryptamine in hypothalamus and some amino acid metabolism. These results suggested that HLJDT relieved fever by acting on multi-targets.

关键词： 2 4-dinitrophenol Heat syndrome Chromatography liquid Metabolism HuanglianjieduTang

Spacecraft angular velocity estimation method using optical flow of stars

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Science China(Information Sciences) 2018年第11期61卷 99-112页

作者： Xiaolin NING Zonghe DING pingping chen Weiren WU Jiancheng FANG Gang LIU School of Instrumentation Science & Opto-electronics Engineering Beihang University Lunar Exploration and Space Program Center China National Space Administration

Angular velocity is a crucial parameter for spacecraft navigation, which, at present, is mainly obtained by using gyroscopes. Several studies have been performed on angular velocity estimation using star sensors when data from gyroscopes are not available. Most of the previous angular velocity estimation methods using star sensors are based on information on the attitude or star vector measurements. In this paper,an angular velocity estimation method using the optical flow(OF) directly from the star images is proposed,which, unlike the previous methods, requires star coordinates in two consecutive images only. Because the procedure of star identification is eliminated, the corresponding high computation requirement is *** demonstrate that the proposed method has a robust performance in terms of computational cost and the number of stars in the field of view(FOV) compared with the previous methods. Finally, certain affecting factors are analyzed, including lens distortion, star senor instantaneous FOV(IFOV), star number,and accuracy of the star sensor.

关键词： angular velocity star sensor optical flow star images Kalman filter