A Novel Approach for QoS Prediction Based on Bayesian Combinational Model

As an important factor in evaluating service,QoS(Quality of Service) has drawn more and more concerns with the rapid increasing of Web services. However,due to the great volatility of services in Mobile Internet environments,such as internet of vehicles,Web services often do not work as announced and thus cause unacceptable problems. QoS prediction can avoid failure before it takes place,which is considered a more effective way to assure quality. However,Current QoS prediction approaches neither consider the highly dynamic of Web services,nor maintain good prediction performance all the time. Consequently we propose a novel Bayesian combinational model to predict QoS by continuously adjusting credit values of the basic models so as to keep good prediction accuracy. QoS attributes such as response time,throughput and reliability are used to validate the proposed model. Experimental results show that the model can provide stable prediction results in Mobile Internet environments.

Flexible control strategy for HVDC transmission system adapted to intermittent new energy delivery

Intermittent new energy delivery requires increasing the flexibility of ultra-high voltage direct current(DC)power adjustment.Based on a converter steady-state model and a DC power model,the control angle constraints of a converter valve are relaxed for power regulation.In this paper,a flexible DC power control method based on a fixed tap changer position is proposed.The initial ratio of the converter transformer is optimized.The effects of the fixed-tap changer position control on the control angle,reactive power compensation,and commutation failure are analyzed.The new control method allows a DC system to operate at a large angle and increase the additional reactive power loss while improving the commutation security margin.Steady-state and electromagnetic transient simulations in the CIGRE test system verify the validity of the method proposed in this paper and the correctness of the analysis conclusions.

A Preliminary Study on the Regularity of Outbreak of Thrips in Asparagus-bean Interplanting Fields

[Objectives]This study was conducted to clarify the composition and occurrence regularity of thrips in asparagus-soybean intercropping fields.[Methods]The species and occurrence dynamics of thrips in asparagus-bean intercropping fields in Luquan District of Shijiazhuang were investigated.[Results]There were 7 species of thrips in this area,namely,tobacco thrips[Thrips alliorum(Priesner)],western flower thrips[Frankliniella occidentalis(Pergande)],Scolothrips takahashii Priesner,Megalurothrips usitatus(Bagrall),Sussericothrips melilotus Han and Aeolothrips fasciatus.As the dominant species,tobacco thrips had two peak outbreaks in late June and late September,and maintained a high quantity level for a long time.Other thrips had fewer population and different occurrence time,but were greatly affected by temperature,humidity and host crop species.[Conclusions]This study provides a theoretical basis for the forecast and comprehensive control of thrips in North China.

Potential and prospects in molecular orbital level micro-electric field for low energy consumption water purification

Conventional water purification technologies struggle to simultaneously address purification efficiency and energy consumption.Molecular orbital level surface micro-electric field(MEF)-driven water purification is an original and innovative concept conceived and developed by our group in recent years.The core idea involves creating electron-rich and electron-poor micro-areas on the nanomaterial surface,which drive pollutants or H_(2)O molecules to provide electrons in the electron-poor micro-areas while other environmental factors(such as H_(2)O_(2)and O_(2))obtain electrons in the electron-rich micro-areas.This process effectively utilizes the internal energy contained within wastewater and emerging contaminants(ECs).Centered on this core,this review systematically examines the discovery,construction,and characteristics of MEF and MEF-like systems and summarizes their application directions.The challenges,bottlenecks,and future development directions of MEF technology are also analyzed and discussed.Reviews of MEFs can facilitate the development of low-consumption,high-efficiency water purification technologies.