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Server load prediction algorithm based on CM-MC for cloud systems

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Journal of Systems Engineering and Electronics 2018年第5期29卷 1069-1078页

作者： XU Xiaolong ZHANG Qitong MOU Yiqi LU Xinyuan Jiangsu Key Laboratory of Big data Security & Intelligent Processing Nanjing University of Posts and Telecommunications State Key Laboratory of Information Security Chinese Academy of Sciences shanghai Stock exchange Technology Co. LtdShanghai Stock Exchange Institute of Big data Research at Yancheng Nanjing University of Posts and Telecommunications

Accurate prediction of server load is important to cloud systems for improving the resource utilization, reducing the energy consumption and guaranteeing the quality of service(QoS).This paper analyzes the features of cloud server load and the advantages and disadvantages of typical server load prediction algorithms, integrates the cloud model(CM) and the Markov chain(MC) together to realize a new CM-MC algorithm, and then proposes a new server load prediction algorithm based on CM-MC for cloud systems. The algorithm utilizes the historical data sample training method of the cloud model, and utilizes the Markov prediction theory to obtain the membership degree vector, based on which the weighted sum of the predicted values is used for the cloud model. The experiments show that the proposed prediction algorithm has higher prediction accuracy than other typical server load prediction algorithms, especially if the data has significant volatility. The proposed server load prediction algorithm based on CM-MC is suitable for cloud systems, and can help to reduce the energy consumption of cloud data centers.

关键词： cloud computing load prediction cloud model Markov chain energy saving

Bias Current Influence on the Characteristic of the Magnetic-controlled Switcher Type Fault Current Limiter

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Journal of shanghai Jiaotong university(Science) 2009年第3期14卷 359-364页

作者：潘艳霞姜建国 Department of Electrical Engineering Shanghai Jiaotong University Power exchange Center of Shanxi Electric Power corporation

A novel magnetic-controlled switcher type fault current limiter （FCL） for high voltage electric network is presented. The current limiting principle of the FCL and the bias current influence on the characteristic of the FCL axe discussed. The experiments on the 220 V/50 A test model show that the FCL can limit the fault current swiftly and effectively. Under the normal state, the bias current adjustment can change the FCL voltage loss; under the fault state, the steady fault current can be easily adjusted to the preset level by bias current regulating. The experimental result is in accordance with the principle analysis and the FCL has the advantages of flexible control strategy and simple and reliable structure.

关键词： fault current limiter (FCL) bias current fault current power systems

Advancing Graph Convolution Network with Revised Laplacian Matrix

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Chinese Journal of Electronics 2020年第6期29卷 1134-1140页

作者： WANG Jiahui GUO Yi WANG Zhihong TANG Qifeng WEN Xinxiu East China University of Science and Technology National Engineering Laboratory for Big data Distribution and exchange Technologies

Graph convolution networks are extremely efficient on the graph-structure data,which both consider the graph and feature *** existing models mainly focus on redefining the complicated network structure,while ignoring the negative impact of lowquality input data during the aggregation *** paper utilizes the revised Laplacian matrix to improve the performance of the original model in the preprocessing *** comprehensive experimental results testify that our proposed model performs significantly better than other off-the-shelf models with a lower computational complexity,which gains relatively higher accuracy and stability.

关键词： Laplacian matrix graph-structure data network structure convolutional neural nets feature information computational complexity data structures graph theory Algebra Computational complexity graph convolution network Neural computing techniques File organisation matrix algebra Combinatorial mathematics

Toward a research framework to conceptualize data as a factor of production:The data marketplace perspective

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Fundamental Research 2021年第5期1卷 586-594页

作者： Lihua Huang Yifan Dou Yezheng Liu Jinzhao Wang Gang Chen Xiaoyang Zhang Runyin Wang School of Management Fudan UniversityShanghai 200433China School of Management Hefei University of TechnologyHefei 230009China shanghai data exchange Coorporadon Shanghai 200436China

The widespread use of machine learning techniques and artificial intelligence algorithms has highlighted the strategic role of *** acquire data for training algorithms and eventually empowering the digital transformation,data marketplaces are often required to support and coordinate cross-organizational data ***,the prior industry practices have suggested that the transaction costs in the data marketplaces are severely high,and the supporting infrastructure is far from *** paper proposes a data attributes-affected data exchange(DADE)conceptual model to understand the challenges and directions for developing data ***,our model framework is built upon two dimensions,data lifecycle maturity and data asset *** on the DADE model,we propose four approaches for developing data marketplaces and discuss future research directions with an overview of computational methods as potential technical solutions.

关键词： data marketplace Factor of production data lifecycle Asset specificity

EXPERIMENTAL INVESTIGATION OF ROTATING STALL FOR A LOW-SPEED CENTRIFUGAL COMPRESSOR

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Chinese Journal of Mechanical Engineering 2008年第3期21卷 76-83页

作者： ZHU Xiaocheng GUO Qiang DU Zhaohui CHEN Hua ZHAO Yan School of Mechanical Engineering Shanghai Jiaotong University Shanghai 200030 China Honeywell corporation Shanghai 200030 China

Unsteady flows and rotating stall of a low-speed centrifugal compressor are investigated by measuring vaneless diffuser wall static pressure fluctuation and internal flow fields at different small flow fluxes. During the experiment, firstly the real time static pressure fluctuations on the vaneless diffuser shroud at different circumferential and radial position were acquired by high-frequency dynamic pressure transducers. Discrete Fourier transformation analysis and cross-correlation analysis were applied to the experimental results to ascertain the rotating stall beginning operation conditions and stall cells numbers and rotating speed. Secondly, the vaneless diffuser inlet flow angle distribution along diffuser width direction was acquired by single hotwire, which was compared with SENOO＇s analysis results. At last, the internal flow fields of the centrifugal compressor were investigated with a particle image velocimetry （PIV） system at different small flow fluxes. The flow field development of vaneless diffuser and blade flow passage are given at rotating stall conditions. The experiments enrich the understanding of rotating stall flow phenomenon of the low-speed centrifugal compressor and provide full experiment data for designing high performance centrifugal compressor.

关键词： Rotating stall Centrifugal compressor Vaneless diffuser Particle image velocimetry (PIV)

Simulation Analysis of Flue Gas Waste Heat Utilization Retrofit Based on ORC System

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Energy Engineering 2023年第8期120卷 1919-1938页

作者： Liqing Yan Jiang Liu Guangwei Ying Ning Zhang College of Energy and Mechanical Engineering Shanghai University of Electric PowerShanghai200090China shanghai Engineering Research Center of Energy-Saving in Heat exchange Systems Shanghai200090China China Huadian corporation Ltd.Shang Hai Company Shanghai200126China Zaozhuang Vocational College Chemical and Pharmaceutical InstituteZaozhuang277000China

Recovery of waste heat from boiler flue gas is an effective way to improve energy utilization *** a heating station heating project as an example,the existing heating system of this heating station was analyzed for its underutilized flue gas waste heat and low energy utilization *** cycle is an effective waste heat recovery method,and a steam boiler organic Rankine cycle(ORC)cogeneration waste heat utilization method is *** system model simulation is constructed and ***,a thermodynamic model was constructed in MATLAB and five suitable work gases were selected to analyze the effects of evaporation temperature and condensation temperature on the network and thermal efficiency of the waste heat cycle power ***,the ORC model is invoked in TRNSYS to construct the improved cogeneration system,and the rationality of the remaining heat utilization methods is determined by calculating and analyzing the thermal performance,economy,and environmental protection of the improved *** simulation results show that the system can generate about 552,000 kWh of electricity per year,and improving the energy utilization rate from 0.72 to 0.78.

关键词： Cogeneration waste heat recovery organic Rankine cycle simulation model

The revolution of the biology of the genome

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Cell Research 2004年第1期14卷 1-7页

作者： WoIfgang HENNIG 320 Yue Yang Road China. Chinese Academy of Sciences German Academic exchange Service (DAAD) Laboratory shanghai 200031 shanghai Institutes for Biological Sciences

Sequence data of entire eukaryotic genomes and their detailed comparison have provided new evidence on genome evolution. The major mechanisms involved in the increase of genome sizes are polyploidization and gene duplication. Subsequent gene silencing or mutations, preferentially in regulatory sequences of genes, modify the genome and permit the development of genes with new properties. Mechanisms such as lateral gene transfer, exon shuffling or the creation of new genes by transposition contribute to the evolution of a genome, but remain of relatively restricted relevance. Mechanisms to decrease genome sizes and, in particular, to remove specific DNA sequences, such as blocks of satellite DNAs, appear to involve the action of RNA interference (RNAi). RNAi mechanisms have been proven to be involved in chromatin packaging related with gene inactivation as well as in DNA excision during the macronucleus development in ciliates.

关键词： genome structure gene duplication RNAi gene silencing chromatin.

Frequency-constrained Co-planning of Generation and Energy Storage with High-penetration Renewable Energy

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Journal of Modern Power Systems and Clean Energy 2021年第4期9卷 760-775页

作者： Chengming Zhang Lu Liu Haozhong Cheng Dundun Liu Jianping Zhang Gang Li Key Laboratory of Control of Power Transmission and Conversion Shanghai Jiao Tong UniversityShanghaiChina East China Branch of State Grid corporation ShanghaiChina

Large-scale renewable energy integration decreases the system inertia and restricts frequency regulation. To maintain the frequency stability, allocating adequate frequency-support sources poses a critical challenge to planners. In this context, we propose a frequency-constrained coordination planning model of thermal units, wind farms, and battery energy storage systems (BESSs) to provide satisfactory frequency supports. Firstly, a modified multi-machine system frequency response (MSFR) model that accounts for the dynamic responses from both synchronous generators and grid-connected inverters is constructed with preset power-headroom. Secondly, the rate-of-change-of-frequency (ROCOF) and frequency response power are deduced to construct frequency constraints. A data-driven piecewise linearization (DDPWL) method based on hyperplane fitting and data classification is applied to linearize the highly nonlinear frequency response power. Thirdly, frequency constraints are inserted into our planning model, while the unit commitment based on the coordinated operation of the thermal-hydro-wind-BESS hybrid system is implemented. At last, the proposed model is applied to the IEEE RTS-79 test system. The results demonstrate the effectiveness of our co-planning model to keep the frequency stability.

关键词： Battery energy storage system(BESS) data-driven piecewise linearization generation planning multi-machine system frequency response unit commitment wind farm

Ozone Profile Retrieval from Satellite Observation Using High Spectral Resolution Infrared Sounding Instrument

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Advances in Atmospheric Sciences 2001年第5期18卷 959-971页

作者： Yanni Qu, Mitchell D. Goldberg and Murty Divakarla Research and data System corporation, 7833 Walker Dr Greenbelt. MD 20770 National Eivironment Satellite data and Information Service, Office of Research and Application, World Weather Building. 5200 Auth Research and data System corporation Greenbelt USA National Environment Satellite data and Information Service Office of Research and Application Camp Springs USA

This paper presents a preliminary result on the retrieval of atmospheric ozone profiles using an im- proved regression technique and utilizing the data from the Atmospheric InfraRed Sounder (AIRS), a hyper-spectral Instrument expected to be flown on the EOS-AQUA platform in 20D2. Simulated AIRS spectra were used to study the sensitivity of AIRS radiance on the tropospheric and stratospheric ozone changes, and to study the impact of various channel combinations on the ozone profile retrieval. Sensitivity study results indicate that the AIRS high resolution spectral channels between the wavenumber 650- 800 cm-1 provide very useful information to accurately retrieve tropospheric and stratospheric ozone pro- files Eigenvector decomposition of AIRS spectra indicate that no more than 100 eigenvectors are needed to retrieve very accurate ozone profiles. The accuracy of the retrieved atmospheric ozone profile from the pres- ent technique and utilizing the AIRS data was compared with the accuracy obtained from current Advanced TIROS Operational Vertical Sounder (ATOVS) data aboard National Oceanic and Atmospheric Admini- stration (NOAA) satellites As expected, a comparison of retrieval results confirms that the ozone profile re- trieved with the AIRS data is superior to that of ATOVS

关键词： AIRS ATOVS Regression Eigenvector Principal component