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A Framework for Cybersecurity Alert Distribution and Response Network (ADRIAN)
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作者 Akarshita Shankar Vijay Madisetti 《Journal of Software Engineering and Applications》 2024年第5期396-420,共25页
Security Information and Event Management (SIEM) platforms are critical for organizations to monitor and manage their security operations centers. However, organizations using SIEM platforms have several challenges su... Security Information and Event Management (SIEM) platforms are critical for organizations to monitor and manage their security operations centers. However, organizations using SIEM platforms have several challenges such as inefficiency of alert management and integration with real-time communication tools. These challenges cause delays and cost penalties for organizations in their efforts to resolve the alerts and potential security breaches. This paper introduces a cybersecurity Alert Distribution and Response Network (Adrian) system. Adrian introduces a novel enhancement to SIEM platforms by integrating SIEM functionalities with real-time collaboration platforms. Adrian leverages the uniquity of mobile applications of collaboration platforms to provide real-time alerts, enabling a two-way communication channel that facilitates immediate response to security incidents and efficient SIEM platform management. To demonstrate Adrian’s capabilities, we have introduced a case-study that integrates Wazuh, a SIEM platform, to Slack, a collaboration platform. The case study demonstrates all the functionalities of Adrian including the real-time alert distribution, alert customization, alert categorization, and enablement of management activities, thereby increasing the responsiveness and efficiency of Adrian’s capabilities. The study concludes with a discussion on the potential expansion of Adrian’s capabilities including the incorporation of artificial intelligence (AI) for enhanced alert prioritization and response automation. 展开更多
关键词 SIEM Platforms Alert distribution Incident response Automation SIEM Management Collaboration Platform
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A Novel Defender-Attacker-Defender Model for Resilient Distributed Generator Planning with Network Reconfiguration and Demand Response
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作者 Wenlu Ji Teng Tu Nan Ma 《Energy Engineering》 EI 2024年第5期1223-1243,共21页
To improve the resilience of a distribution system against extreme weather,a fuel-based distributed generator(DG)allocation model is proposed in this study.In this model,the DGs are placed at the planning stage.When a... To improve the resilience of a distribution system against extreme weather,a fuel-based distributed generator(DG)allocation model is proposed in this study.In this model,the DGs are placed at the planning stage.When an extreme event occurs,the controllable generators form temporary microgrids(MGs)to restore the load maximally.Simultaneously,a demand response program(DRP)mitigates the imbalance between the power supply and demand during extreme events.To cope with the fault uncertainty,a robust optimization(RO)method is applied to reduce the long-term investment and short-term operation costs.The optimization is formulated as a tri-level defenderattacker-defender(DAD)framework.At the first level,decision-makers work out the DG allocation scheme;at the second level,the attacker finds the optimal attack strategy with maximum damage;and at the third level,restoration measures,namely distribution network reconfiguration(DNR)and demand response are performed.The problem is solved by the nested column and constraint generation(NC&CG)method and the model is validated using an IEEE 33-node system.Case studies validate the effectiveness and superiority of the proposed model according to the enhanced resilience and reduced cost. 展开更多
关键词 distribution system RESILIENCE defender-attacker-defender distributed generator demand response microgrids formation
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Research on Corporate Social Responsibility Evaluation Based on Improved CRITIC-TOPSIS—A Case Study of Listed Companies in China’s Pharmaceutical Distribution Industry 被引量:1
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作者 Lili Liu Yingyu Wu Jingxian Liu 《Open Journal of Applied Sciences》 CAS 2023年第5期704-719,共16页
Corporate social responsibility (CSR) has garnered considerable attention from countries, institutions, enterprises and social groups. However, the lack of research on CSR evaluation system for industries has impeded ... Corporate social responsibility (CSR) has garnered considerable attention from countries, institutions, enterprises and social groups. However, the lack of research on CSR evaluation system for industries has impeded its development and construction across various industries. Therefore, given the close association of pharmaceutical distribution enterprises with personal health, there exists a pressing need to explore the CSR in this domain. This paper establishes a CSR evaluation index system for pharmaceutical distribution enterprises, employing a combination of documentary analysis and in-depth interviews. This index system comprises 7 CSR criterion layers (e.g., responsible governance and employee responsibility) and 56 index layers. 25 listed companies in China’s pharmaceutical distribution industry are chosen as research objects, and this study also establishes an evaluation model for the CSR of pharmaceutical distribution companies through the improved Criteria Importance Though Intercrieria Correlation (CRITIC) method combined with The Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method. The empirical analysis reveals that the responsible governance criterion layer and the social development criterion layer demonstrate the best performance, while the supplier, customer and patient responsibility criterion layer exhibit the worst performance. 展开更多
关键词 Pharmaceutical distribution Enterprises Corporate Social responsibility Evaluation System Improved CRITIC-TOPSIS
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Reliability-based Robust Optimization Design of Automobile Components with Non-normal Distribution Parameters 被引量:14
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作者 YANG Zhou ZHANG Yimin +2 位作者 HUANG Xianzhen ZHANG Xufang TANG Le 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第4期823-830,共8页
In the reliability designing procedure of the vehicle components, when the distribution styles of the random variables are unknown or non-normal distribution, the result evaluated contains great error or even is wrong... In the reliability designing procedure of the vehicle components, when the distribution styles of the random variables are unknown or non-normal distribution, the result evaluated contains great error or even is wrong if the reliability value R is larger than 1 by using the existent method, in which case the formula is necessary to be revised. This is obviously inconvenient for programming. Combining reliability-based optimization theory, robust designing method and reliability based sensitivity analysis, a new method for reliability robust designing is proposed. Therefore the influence level of the designing parameters’ changing to the reliability of vehicle components can be obtained. The reliability sensitivity with respect to design parameters is viewed as a sub-objective function in the multi-objective optimization problem satisfying reliability constraints. Given the first four moments of basic random variables, a fourth-moment technique and the proposed optimization procedure can obtain reliability-based robust design of automobile components with non-normal distribution parameters accurately and quickly. By using the proposed method, the distribution style of the random parameters is relaxed. Therefore it is much closer to the actual reliability problems. The numerical examples indicate the following: (1) The reliability value obtained by the robust method proposed increases (】0.04%) comparing to the value obtained by the ordinary optimization algorithm; (2) The absolute value of reliability-based sensitivity decreases (】0.01%), and the robustness of the products’ quality is improved accordingly. Utilizing the reliability-based optimization and robust design method in the reliability designing procedure reduces the manufacture cost and provides the theoretical basis for the reliability and robust design of the vehicle components. 展开更多
关键词 fourth-moment technique reliability robust design reliability optimization non-normal distribution parameters
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A new early warning method for dam displacement behavior based on non-normal distribution function 被引量:2
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作者 Zhen-xiang Jiang Hui Chen 《Water Science and Engineering》 EI CAS CSCD 2022年第2期170-178,共9页
Traditional methods for early warning of dam displacements usually assume that residual displacements follow a normal distribution.This assumption deviates from the reality,thereby affecting the reliability of early w... Traditional methods for early warning of dam displacements usually assume that residual displacements follow a normal distribution.This assumption deviates from the reality,thereby affecting the reliability of early warning results and leading to misjudgments of dam displacement behavior.To solve this problem,this study proposed an early warning method using a non-normal distribution function.A new early warning index was developed using cumulative distribution function(CDF)values.The method of kernel density estimation was used to calculate the CDF values of residual displacements at a single point.The copula function was used to compute the CDF values of residual displacements at multiple points.Numerical results showed that,with residual displacements in a non-normal distribution,the early warning method proposed in this study accurately reflected the dam displacement behavior and effectively reduced the frequency of false alarms.This method is expected to aid in the safe operation of dams. 展开更多
关键词 non-normal distribution Dam displacement Early warning index Kernel density estimation Copula function
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Influence of porosity distribution on nonlinear free vibration and transient responses of porous functionally graded skew plates 被引量:5
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作者 Naveen Kumar H S Subhaschandra Kattimani TNguyen-Thoi 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2021年第6期1918-1935,共18页
This article deals with the investigation of the effects of porosity distributions on nonlinear free vibration and transient analysis of porous functionally graded skew(PFGS)plates.The effective material properties of... This article deals with the investigation of the effects of porosity distributions on nonlinear free vibration and transient analysis of porous functionally graded skew(PFGS)plates.The effective material properties of the PFGS plates are obtained from the modified power-law equations in which gradation varies through the thickness of the PFGS plate.A nonlinear finite element(FE)formulation for the overall PFGS plate is derived by adopting first-order shear deformation theory(FSDT)in conjunction with von Karman’s nonlinear strain displacement relations.The governing equations of the PFGS plate are derived using the principle of virtual work.The direct iterative method and Newmark’s integration technique are espoused to solve nonlinear mathematical relations.The influences of the porosity distributions and porosity parameter indices on the nonlinear frequency responses of the PFGS plate for different skew angles are studied in various parameters.The effects of volume fraction grading index and skew angle on the plate’s nonlinear dynamic responses for various porosity distributions are illustrated in detail. 展开更多
关键词 Porous functionally graded skew plates Porosity distributions Nonlinear transient response Nonlinear frequency ratio Nonlinear frequency parameter
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Electric field distribution and effective nonlinear AC and DC responses of graded cylindrical composites 被引量:1
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作者 丁霞 贾艳霞 魏恩泊 《Chinese Physics B》 SCIE EI CAS CSCD 2012年第5期569-576,共8页
The perturbation method is used to study the localization of electric field distribution and the effective nonlinear response of graded composites under an external alternating-current(AC) and direct-current(DC) e... The perturbation method is used to study the localization of electric field distribution and the effective nonlinear response of graded composites under an external alternating-current(AC) and direct-current(DC) electric field E app = E 0(1 + sin ωt).The dielectric profile of the cylindrical inclusions is modeled by function ε i(r) = C k r k(r ≤ a),where r is the radius of the cylindrical inclusion,and C k,k,a are parameters.In the dilute limit,the local potentials and the effective nonlinear responses at all harmonics are derived.Meanwhile,the general effective nonlinear responses are also derived and compared with the effective nonlinear responses at harmonics under the AC and DC external field.It is found that the effective nonlinear AC and DC responses at harmonics can be calculated by those of the general effective nonlinear of the graded composites under the external DC electric field.Moreover,the obtained local electrical fields show that the electrical field distribution in the cylindrical inclusions is controllable,and the maximum of the electric field inside the cylinder is at its center. 展开更多
关键词 graded composite effective nonlinear alternating-current and direct-current response local electric field distribution
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DISTRIBUTION LAW OF RANDOM UNBALANCE RESPONSE OF MULTISTAGE BLOWER
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作者 Tan, Qing Zhong, Jue 《中国有色金属学会会刊:英文版》 EI CSCD 1998年第1期165-168,共4页
DISTRIBUTIONLAWOFRANDOMUNBALANCERESPONSEOFMULTISTAGEBLOWER①TanQingandZhongJueColegeofMechanicalandElectrical... DISTRIBUTIONLAWOFRANDOMUNBALANCERESPONSEOFMULTISTAGEBLOWER①TanQingandZhongJueColegeofMechanicalandElectricalEnginering,Centra... 展开更多
关键词 UNBALANCE distribution RANDOM experiment method vibration response centrifugal BLOWER overcritical rotating speed autobalance technology working condition diagnosis
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The Natural Probability Distribution of Load and Unload Response Ratio
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作者 Chen Qifu,Yin Xiangchu,and Ma LiCenter for Analysis and Prediction,SSB,Beijing 100036,China 《Earthquake Research in China》 1997年第1期43-49,共7页
In this paper,the Gutenberg-Richter model is used to generate seismic events.The events that satisfy the random distribution are also generated.With those events,the natural probability distribution of Load and Unload... In this paper,the Gutenberg-Richter model is used to generate seismic events.The events that satisfy the random distribution are also generated.With those events,the natural probability distribution of Load and Unload Response Ratio(LURR),which measures quantitatively the degree of instability of a nonlinear system,is discussed.The study is based on stress energy release,which is chosen as the response of nonlinear system F3.The comparative results from the observation catalogue and generating data are also studied.It is revealed that the natural probability of LURR is mostly stable when the sample number is sufficient.The lower the natural probability of LURR,the more the precursory is information it may contain.The influence of Y3 resulting from the sample number and the magnitude range of events is also discussed. 展开更多
关键词 NATURAL PROBABILITY distribution System EVENT load-unload response ratio.
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The Random Distribution of the Loading and Unloading Response Ratio Under the Assumptions of Poisson Models
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作者 Zhuang Jiancang and Yin XiangchuCentre for Analysis and Prediction,CSB,Beijing 100036,China Research Center of Exploration Geophysics,CSB,Zhengzhou 450002,China Laboratory of Nonlinear Mechanics, Institute of Mechanics,Chinese Academy of Sciences,Beijing 100080,China 《Earthquake Research in China》 2000年第1期42-52,共11页
This paper discussed the random distribution of the loading and unloading response ratio(LURR) of different definitions(Y<sub>1</sub>~Y<sub>5</sub>)using the assumptions that the earthquak... This paper discussed the random distribution of the loading and unloading response ratio(LURR) of different definitions(Y<sub>1</sub>~Y<sub>5</sub>)using the assumptions that the earthquakes occurfollowing the Poisson process and their magnitudes obey the Gutenberg-Richter law.Theresults show that Y<sub>1</sub>~Y<sub>5</sub> are quite stable or concentrated when the expected number of eventsin the calculation time window is relatively large(】40);but when this occurrence ratebecomes very small,Y<sub>2</sub>~Y<sub>5</sub> become quite variable or unstable.That is to say,a high value ofthe LURR can be produced not only from seismicity before a large earthquake,but also from arandom sequence of earthquakes that obeys a Poisson process when the expected number ofevents in the window is too small.To check the influence of randomness in the catalogue tothe LURR,the random distribution of the LURR under Poisson models has been calculated bysimulation.90%,95% and 99% confidence ranges of Y<sub>1</sub> and Y<sub>3</sub> are given in this paper,which is helpful to quantify the random 展开更多
关键词 Loading and UNLOADING response ratio POISSON Model Gutenberg-Richter LAW RANDOM distribution CONFIDENCE BAND
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Distributed Collaborative Response Surface Method for Mechanical Dynamic Assembly Reliability Design 被引量:25
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作者 BAI Guangchen FEI Chengwei 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第6期1160-1168,共9页
Because of the randomness of many impact factors influencing the dynamic assembly relationship of complex machinery, the reliability analysis of dynamic assembly relationship needs to be accomplished considering the r... Because of the randomness of many impact factors influencing the dynamic assembly relationship of complex machinery, the reliability analysis of dynamic assembly relationship needs to be accomplished considering the randomness from a probabilistic perspective. To improve the accuracy and efficiency of dynamic assembly relationship reliability analysis, the mechanical dynamic assembly reliability(MDAR) theory and a distributed collaborative response surface method(DCRSM) are proposed. The mathematic model of DCRSM is established based on the quadratic response surface function, and verified by the assembly relationship reliability analysis of aeroengine high pressure turbine(HPT) blade-tip radial running clearance(BTRRC). Through the comparison of the DCRSM, traditional response surface method(RSM) and Monte Carlo Method(MCM), the results show that the DCRSM is not able to accomplish the computational task which is impossible for the other methods when the number of simulation is more than 100 000 times, but also the computational precision for the DCRSM is basically consistent with the MCM and improved by 0.40-4.63% to the RSM, furthermore, the computational efficiency of DCRSM is up to about 188 times of the MCM and 55 times of the RSM under 10000 times simulations. The DCRSM is demonstrated to be a feasible and effective approach for markedly improving the computational efficiency and accuracy of MDAR analysis. Thus, the proposed research provides the promising theory and method for the MDAR design and optimization, and opens a novel research direction of probabilistic analysis for developing the high-performance and high-reliability of aeroengine. 展开更多
关键词 machinery dynamic assembly reliability analysis distributed collaborative response surface method blade-tip radial running clearance
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Reliability analysis for aeroengine turbine disc fatigue life with multiple random variables based on distributed collaborative response surface method 被引量:2
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作者 高海峰 白广忱 +1 位作者 高阳 鲍天未 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第12期4693-4701,共9页
The fatigue life of aeroengine turbine disc presents great dispersion due to the randomness of the basic variables,such as applied load,working temperature,geometrical dimensions and material properties.In order to am... The fatigue life of aeroengine turbine disc presents great dispersion due to the randomness of the basic variables,such as applied load,working temperature,geometrical dimensions and material properties.In order to ameliorate reliability analysis efficiency without loss of reliability,the distributed collaborative response surface method(DCRSM) was proposed,and its basic theories were established in this work.Considering the failure dependency among the failure modes,the distributed response surface was constructed to establish the relationship between the failure mode and the relevant random variables.Then,the failure modes were considered as the random variables of system response to obtain the distributed collaborative response surface model based on structure failure criterion.Finally,the given turbine disc structure was employed to illustrate the feasibility and validity of the presented method.Through the comparison of DCRSM,Monte Carlo method(MCM) and the traditional response surface method(RSM),the results show that the computational precision for DCRSM is more consistent with MCM than RSM,while DCRSM needs far less computing time than MCM and RSM under the same simulation conditions.Thus,DCRSM is demonstrated to be a feasible and valid approach for improving the computational efficiency of reliability analysis for aeroengine turbine disc fatigue life with multiple random variables,and has great potential value for the complicated mechanical structure with multi-component and multi-failure mode. 展开更多
关键词 complicated mechanical structure reliability analysis multiple random variables multi-component and multi-failure mode distributed collaborative response surface method
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Distributed collaborative extremum response surface method for mechanical dynamic assembly reliability analysis 被引量:7
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作者 费成巍 白广忱 《Journal of Central South University》 SCIE EI CAS 2013年第9期2414-2422,共9页
To make the dynamic assembly reliability analysis more effective for complex machinery of multi-object multi-discipline(MOMD),distributed collaborative extremum response surface method(DCERSM)was proposed based on ext... To make the dynamic assembly reliability analysis more effective for complex machinery of multi-object multi-discipline(MOMD),distributed collaborative extremum response surface method(DCERSM)was proposed based on extremum response surface method(ERSM).Firstly,the basic theories of the ERSM and DCERSM were investigated,and the strengths of DCERSM were proved theoretically.Secondly,the mathematical model of the DCERSM was established based upon extremum response surface function(ERSF).Finally,this model was applied to the reliability analysis of blade-tip radial running clearance(BTRRC)of an aeroengine high pressure turbine(HPT)to verify its advantages.The results show that the DCERSM can not only reshape the possibility of the reliability analysis for the complex turbo machinery,but also greatly improve the computational speed,save the computational time and improve the computational efficiency while keeping the accuracy.Thus,the DCERSM is verified to be feasible and effective in the dynamic assembly reliability(DAR)analysis of complex machinery.Moreover,this method offers an useful insight for designing and optimizing the dynamic reliability of complex machinery. 展开更多
关键词 complex machinery dynamic assembly reliability (DAR) blade-tip radial running clearance (BTRRC) radial deformation reliability analysis distributed collaborative extremum response surface method (DCERSM) multi-object multidiscipline (MOMD)
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Research on Application Technology Oriented Rapid Response Manufacturing in the Distributed Network Environment
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作者 JIN Ji-wen, NI Yan-rong, XI Jun-tong, FAN Fei-ya, JIN Ye (CIM Institute, Department of Mechanical Engineering, Shanghai Jiaotong University, Shanghai 200030, China) 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期43-44,共2页
A new chance of developing traditional manufacturing industry comes forth with the development of network technology. Application technology oriented rapid response manufacturing in the distributed network environment... A new chance of developing traditional manufacturing industry comes forth with the development of network technology. Application technology oriented rapid response manufacturing in the distributed network environments, that is, how to take advantage of the Intranet and Internet, combine the numerous manufacturing resources spread around the region, the country and even the globe is the key to the agile design, manufacturing and the buildup of comprehensively competitive power, at the same time, is also an important research direction in the field of advanced manufacturing technology. Rapid response manufacturing in the distributed network environment is a newly manufactory pattern that can be used to implement the conception of agile design and manufacturing, but there are some new problems coming with it, which will directly influence the enterprise’s ability of rapid response in the distributed network manufacturing pattern and lead to the failure of the league and the lost of the given orders. In this paper, we establish some approaches to solve these problems in product development process. The paper then presents the research on key application technologies and solutions includes: network safety strategy which guarantees data transferring among the leaguer members, production data management based on Web/DOT (Distributed Object Technology) and XML criteria which guarantees data exchange in structure-variance characteristic environments, the network platform which provides the conversion service of different types of CAD files each other. All of these solutions are aim for technology problems existing in the distributed network environments and among the league members. Finally, the paper takes one project, that is, the establishment of the online application service system for Shanghai Advance Manufacturing Technology Research Center as a good instance. 展开更多
关键词 distributed network environment rapid response manufacturing data exchange
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Temporal response of laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure:Model and simulation
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作者 Zi-Heng Wang Yi-Jun Zhang +7 位作者 Shi-Man Li Shan Li Jing-Jing Zhan Yun-Sheng Qian Feng Shi Hong-Chang Cheng Gang-Cheng Jiao Yu-Gang Zeng 《Chinese Physics B》 SCIE EI CAS CSCD 2022年第9期628-635,共8页
To describe the dynamic response characteristics of the laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure,a general theoretical temporal response model is deduced by combinin... To describe the dynamic response characteristics of the laminated graded-bandgap GaAs-based photocathode with distributed Bragg reflection structure,a general theoretical temporal response model is deduced by combining the unsteady continuity equation and numerical calculation method.Through the model,the contribution of the distribution Bragg reflec-tion structure and graded-bandgap emission layer to the temporal response are investigated.Meanwhile,the relationships between the temporal response characteristics of the laminated GaAs-based photocathode and different structural parame-ters are also analyzed,including average electron decay time,emission layer thickness,and incident light wavelength.It is found that the introduction of distribution Bragg reflection(DBR)layer solves the discrepancy between the absorption capability of the emission layer and the temporal response.Moreover,the distributed Bragg reflection layer can improve the time response by optimizing the initial photoelectron distribution.The improvement effect of the DBR layer on the temporal response is enhanced with the emission layer thickness decreasing or the incident light wavelength increasing.These results explain the effect of the DBR layer of the photocathode on the dynamic characteristics,which can offer a new insight into the dynamic research of GaAs-based photocathode. 展开更多
关键词 temporal response GaAs-based photocathode distribution Bragg reflection graded-bandgap
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Fast Distributed Demand Response Algorithm in Smart Grid 被引量:2
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作者 Qifen Dong Li Yu +3 位作者 Wenzhan Song Junjie Yang Yuan Wu Jun Qi 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2017年第2期280-296,共17页
This paper proposes a fast distributed demand response U+0028 DR U+0029 algorithm for future smart grid based on primaldual interior method and Gaussian belief propagation U+0028 GaBP U+0029 solver. At the beginning o... This paper proposes a fast distributed demand response U+0028 DR U+0029 algorithm for future smart grid based on primaldual interior method and Gaussian belief propagation U+0028 GaBP U+0029 solver. At the beginning of each time slot, each end-user U+002F energysupplier exchanges limited rounds of messages that are not private with its neighbors, and computes the amount of energy consumption U+002F generation locally. The proposed demand response algorithm converges rapidly to a consumption U+002F generation decision that yields the optimal social welfare when the demands of endusers are low. When the demands are high, each end-user U+002F energysupplier estimates its energy consumption U+002F generation quickly such that a sub-optimal social welfare is achieved and the power system is ensured to operate within its capacity constraints. The impact of distributed computation errors on the proposed algorithm is analyzed theoretically. The simulation results show a good performance of the proposed algorithm. © 2017 Chinese Association of Automation. 展开更多
关键词 Electric power transmission networks Energy utilization
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Prediction of Short-Term Distributions of Load Extremes of Offshore Wind Turbines 被引量:2
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作者 王迎光 《China Ocean Engineering》 SCIE EI CSCD 2016年第6期851-866,共16页
This paper proposes a new methodology to select an optimal threshold level to be used in the peak over threshold (POT) method for the prediction of short-term distributions of load extremes of offshore wind turbines... This paper proposes a new methodology to select an optimal threshold level to be used in the peak over threshold (POT) method for the prediction of short-term distributions of load extremes of offshore wind turbines. Such an optimal threshold level is found based on the estimation of the variance-to-mean ratio for the occurrence of peak values, which characterizes the Poisson assumption. A generalized Pareto distribution is then fitted to the extracted peaks over the optimal threshold level and the distribution parameters are estimated by the method of the maximum spacing estimation. This methodology is applied to estimate the short-term distributions of load extremes of the blade bending moment and the tower base bending moment at the mudline of a monopile-supported 5MW offshore wind turbine as an example. The accuracy of the POT method using the optimal threshold level is shown to be better, in terms of the distribution fitting, than that of the POT methods using empirical threshold levels. The comparisons among the short-term extreme response values predicted by using the POT method with the optimal threshold levels and with the empirical threshold levels and by using direct simulation results further substantiate the validity of the proposed new methodology. 展开更多
关键词 extreme responses monopile-supported offshore wind turbine peak over threshold method optimalthreshold level variance-to-mean ratio generalized Pareto distribution maximum spacing estimation
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Vertical Distribution of Soil Nematode Communities under Different Tillage Systems in Lower Reaches of Liaohe River 被引量:2
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作者 HOU Xuekun HU Ning +2 位作者 ZHANG Xiaoke LIANG Lei ZHAI Ruichang 《Chinese Geographical Science》 SCIE CSCD 2010年第2期106-111,共6页
Vertical distribution of soil nematode communities under conventional tillage (CT),no-tillage (NT) and fallow field (FF) treatments in the Lower Reaches of the Liaohe River was investigated at six soil depths (0-5 cm,... Vertical distribution of soil nematode communities under conventional tillage (CT),no-tillage (NT) and fallow field (FF) treatments in the Lower Reaches of the Liaohe River was investigated at six soil depths (0-5 cm,5-15 cm,15-30 cm,30-50 cm,50-75 cm and 75-100 cm). The results show that total nematode abundance gradually decreases with depth,and the highest number of total nematodes is observed at 0-5 cm depth under NT and FF treatments. The number of fungivores and plant parasites is significantly higher under FF and NT treatments than under CT treatment at the 0-5 cm depth. There is significant soil depth effect on the abundances of bacterivores and omnivores-predators,which exhibits a similar trend to that of total nematodes; whereas,no significant tillage effect is found. Tillage effect on soil nematode communities can be reflected by values of relative tillage response of index V. Results of index V indicate that total nematodes,bacterivores,fungivores and plant parasites are mildly inhibited,and omnivores-predators is moderately inhibited under CT treatment; while,under FF treatment total nematodes is mildly,and fungivores and plant parasites are moderately stimulated,respectively. 展开更多
关键词 soil nematode tillage system vertical distribution tillage response
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A modified lumped parameter model of distribution transformer winding 被引量:5
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作者 Qingqing Ding Yao Yao +5 位作者 Bingqian Wang Jingwei Fu Wei Zhang Chao Zeng Xiaoping Li Stanimir Valtchev 《Global Energy Interconnection》 2020年第2期158-165,共8页
The modelling of the distribution transformer winding is the starting point and serves as important basis for the transformer characteristics analysis and the lightning pulse response prediction.A distributed paramete... The modelling of the distribution transformer winding is the starting point and serves as important basis for the transformer characteristics analysis and the lightning pulse response prediction.A distributed parameters model can depict the winding characteristics accurately,but it requires complex calculations.Lumped parameter model requires less calculations,but its applicable frequency range is not wide.This paper studies the amplitude-frequency characteristics of the lightning wave,compares the transformer modelling methods and finally proposes a modified lumped parameter model,based on the above comparison.The proposed model minimizes the errors provoked by the lumped parameter approximation,and the hyperbolic functions of the distributed parameter model.By this modification it becomes possible to accurately describe the winding characteristics and rapidly obtain the node voltage response.The proposed model can provide theoretical and experimental support to lightning protection of the distribution transformer. 展开更多
关键词 Wide band frequency response distributed parameter model Lumped parameter model distribution transformer Lightning protection
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Experimental investigation on dynamic response and damage models of circular RC columns subjected to underwater explosions 被引量:4
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作者 Tie-shuan Zhuang Ming-yang Wang +3 位作者 Jun Wu Cheng-yu Yang Tao Zhang Chao Gao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2020年第4期856-875,共20页
Reinforced concrete(RC) columns are widely used as supporting structures for high-piled wharfs.The study of damage model of a RC column due to underwater explosion is a critical issue to assess the wharfs antiknock se... Reinforced concrete(RC) columns are widely used as supporting structures for high-piled wharfs.The study of damage model of a RC column due to underwater explosion is a critical issue to assess the wharfs antiknock security.In this study,the dynamic response and damage model of circular RC columns subjected to underwater explosions were investigated by means of scaled-down experiment models.Experiments were carried out in a 10.0 m diameter tank with the water depth of 2.25 m,under different explosive quantities(0.025 kg-1.6 kg),stand-off distances(0.0 m-7.0 m),and detonation depths(0.25 m-2.0 m).The shock wave load and dynamic response of experiment models were measured by configuring sensors of pressure,acceleration,strain,and displacement.Then,the load distribution characteristics,time history of test data,and damage models related to present conditions were obtained and discussed.Three damage models,including bending failure,bending-shear failure and punching failure,were identified.In addition,the experie nce model of shock wave loads on the surface of a RC column was proposed for engineering application. 展开更多
关键词 Underwater explosion Reinforced concrete(RC)columns Load distribution characteristics Dynamic response Damage models
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