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Discrete event model-based simulation for train movement on a single-line railway 被引量:2
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作者 徐小明 李克平 杨立兴 《Chinese Physics B》 SCIE EI CAS CSCD 2014年第8期233-239,共7页
The aim of this paper is to present a discrete event model-based approach to simulate train movement with the con- sidered energy-saving factor. We conduct extensive case studies to show the dynamic characteristics of... The aim of this paper is to present a discrete event model-based approach to simulate train movement with the con- sidered energy-saving factor. We conduct extensive case studies to show the dynamic characteristics of the traffic flow and demonstrate the effectiveness of the proposed approach. The simulation results indicate that the proposed discrete event model-based simulation approach is suitable for characterizing the movements of a group of trains on a single railway line with less iterations and CPU time. Additionally, some other qualitative and quantitative characteristics are investigated. In particular, because of the cumulative influence from the previous trains, the following trains should be accelerated or braked frequently to control the headway distance, leading to more energy consumption. 展开更多
关键词 train movement discrete event model RAILWAY energy saving
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A discrete-event model to simulate the effect of truck bunching due to payload variance on cycle time, hauled mine materials and fuel consumption 被引量:2
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作者 A.Soofastaei S.M.Aminossadati +1 位作者 M.S.Kizil P.Knights 《International Journal of Mining Science and Technology》 SCIE EI CSCD 2016年第5期745-752,共8页
Data collected from truck payload management systems at various surface mines shows that the payload variance is significant and must be considered in analysing the mine productivity,energy consumption,greenhouse gas ... Data collected from truck payload management systems at various surface mines shows that the payload variance is significant and must be considered in analysing the mine productivity,energy consumption,greenhouse gas emissions and associated cost.Payload variance causes significant differences in gross vehicle weights.Heavily loaded trucks travel slower up ramps than lightly loaded trucks.Faster trucks are slowed by the presence of slower trucks,resulting in‘bunching’,production losses and increasing fuel consumptions.This paper simulates the truck bunching phenomena in large surface mines to improve truck and shovel systems’efficiency and minimise fuel consumption.The study concentrated on completing a practical simulation model based on a discrete event method which is most commonly used in this field of research in other industries.The simulation model has been validated by a dataset collected from a large surface mine in Arizona state,USA.The results have shown that there is a good agreement between the actual and estimated values of investigated parameters. 展开更多
关键词 Discrete-event model Simulation Truck bunching Payload variance Cycle time Fuel consumption
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基于Event模型的城市物流无人机同高度交叉运行间隔研究
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作者 张健 赵嶷飞 +2 位作者 卢飞 黎宗孝 罗鑫悦 《中国安全科学学报》 北大核心 2025年第5期99-105,共7页
为解决城市物流无人机飞行流量加大、隔离航线模式空域利用率低的矛盾,需要实施安全有效的交叉运行。通过研究交叉运行碰撞风险,确定侧向误差、垂直误差、纵向临近率等核心参数,构建同高度交叉运行间隔模型。在此基础上,进一步考虑机载... 为解决城市物流无人机飞行流量加大、隔离航线模式空域利用率低的矛盾,需要实施安全有效的交叉运行。通过研究交叉运行碰撞风险,确定侧向误差、垂直误差、纵向临近率等核心参数,构建同高度交叉运行间隔模型。在此基础上,进一步考虑机载冲突探测与解脱(CDR)系统失效问题,并运用事件树分析方法,提出并构建城市物流无人机交叉间隔综合模型。结果表明:在航线夹角为60°情况下,对标安全目标水平1.5×10^(-8),所需交叉间隔为158 m;对标安全目标水平1×10^(-6),所需交叉间隔155 m。随着交叉角度增大,运行间隔总体呈现上升趋势,当接近180°时,即对头运行时,所需间隔急剧上升,与实际认知一致。 展开更多
关键词 event模型 城市物流无人机(UAV) 同高度 交叉运行 交叉间隔 冲突探测与解脱(CDR)
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基于Event-B的区块链Raft共识形式化建模方法
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作者 陈中绪 任睿 崔慧敏 《山西电子技术》 2025年第2期97-99,共3页
Raft共识机制是一个关键的分布式系统组件,用于确保数据一致性和容错性。在工业互联网等领域,数据的准确性和系统的可用性至关重要。通过Event-B方法,可以精确地规约Raft共识机制的行为和性质,确保其在各种情况下能够正确运行。基于此,... Raft共识机制是一个关键的分布式系统组件,用于确保数据一致性和容错性。在工业互联网等领域,数据的准确性和系统的可用性至关重要。通过Event-B方法,可以精确地规约Raft共识机制的行为和性质,确保其在各种情况下能够正确运行。基于此,提出一种基于Event-B方法的区块链Raft共识机制的形式化建模方法,以期为Raft共识机制的设计、开发和维护提供更高的可信度。 展开更多
关键词 Raft共识算法 event-B方法 形式化建模
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基于改进Event模型的通用航空器碰撞风险分析
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作者 黄晋 焦瑶瑶 +1 位作者 李云飞 刘厚荣 《火力与指挥控制》 CSCD 北大核心 2024年第10期191-196,共6页
随着通用航空的发展,空中交通流量将持续扩大,航空器碰撞风险增加。对Event模型进行改进,将拼接四棱锥碰撞盒代替原长方体碰撞盒,曲面间隔层代替平面间隔层,建立通用航空器碰撞风险模型。最后将塞斯纳172及运5B通用航空器作为实例对所... 随着通用航空的发展,空中交通流量将持续扩大,航空器碰撞风险增加。对Event模型进行改进,将拼接四棱锥碰撞盒代替原长方体碰撞盒,曲面间隔层代替平面间隔层,建立通用航空器碰撞风险模型。最后将塞斯纳172及运5B通用航空器作为实例对所建模型进行验证,结果表明,在两组均采用广义帕累托分布的条件下,改进后Event模型碰撞风险值分别为改进前的31.65%、14.98%,碰撞风险值较改进前大大减少,结果精度更高,能更好地评估交叉航路碰撞风险。 展开更多
关键词 event模型 碰撞风险 曲面间隔层 广义帕累托分布
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Efficient Deviation Detection Between a Process Model and Event Logs 被引量:4
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作者 Lu Wang Yuyue Du Liang Qi 《IEEE/CAA Journal of Automatica Sinica》 SCIE EI CSCD 2019年第6期1352-1364,共13页
Business processes described by formal or semi-formal models are realized via information systems.Event logs generated from these systems are probably not consistent with the existing models due to insufficient design... Business processes described by formal or semi-formal models are realized via information systems.Event logs generated from these systems are probably not consistent with the existing models due to insufficient design of the information system or the system upgrade.By comparing an existing process model with event logs,we can detect inconsistencies called deviations,verify and extend the business process model,and accordingly improve the business process.In this paper,some abnormal activities in business processes are formally defined based on Petri nets.An efficient approach to detect deviations between the process model and event logs is proposed.Then,business process models are revised when abnormal activities exist.A clinical process in a healthcare information system is used as a case study to illustrate our work.Experimental results show the effectiveness and efficiency of the proposed approach. 展开更多
关键词 DETECT DEVIATIONS event LOG model repair PETRI net process model
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Catalytic Cracking of Cycloparaffins Admixed with Olefins:1. Single-Event Microkinetic(SEMK) Modeling 被引量:3
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作者 Xue Gaoping Weng Huixin +1 位作者 Thybaut Joris W. Marin Guy B. 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2014年第1期71-80,共10页
Single-event microkinetic(SEMK) model of the catalytic cracking of methylcyclohexane admixed with 1-octene over REUSY zeolites at 693 K—753 K in the absence of coke formation is enhanced. To keep consistency with the... Single-event microkinetic(SEMK) model of the catalytic cracking of methylcyclohexane admixed with 1-octene over REUSY zeolites at 693 K—753 K in the absence of coke formation is enhanced. To keep consistency with the wellknown carbenium ion chemistry, hydride transfer forming and consuming allylic carbenium ions in the aromatization of cycloparaffins are further investigated and differentiated. The reversibility of endocyclic β-scission and cyclization reactions is refined by accounting explicitly for the reacting olefins and resulting cycloparaffins in the corresponding thermodynamics. 24 activation energies for the reactions involved in the cracking of cycloparaffins are obtained by the regression of 15 sets of experimental data upon taking the resulting 37 main cracking products, i. e., responses into account. The enhanced SEMK model can adequately describe the catalytic behavior of 37 main products with conversion and temperature. 展开更多
关键词 catalytic cracking single-event microkinetic model cycloparaffin OLEFIN CATALYSIS
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Sensitivities of Numerical Model Forecasts of Extreme Cyclone Events 被引量:5
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作者 A. C. Yih J. E. Walsh 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 1991年第1期51-66,共16页
A global forecast model is used to examine various sensitivities of numerical predictions of three extreme winter storms that occurred near the eastern continental margin of North America: the Ohio Valley blizzard of ... A global forecast model is used to examine various sensitivities of numerical predictions of three extreme winter storms that occurred near the eastern continental margin of North America: the Ohio Valley blizzard of January 1978, the New England blizzard of February 1978, and the Mid-Atlantic cyclone of February 1979. While medium-resolution simulations capture much of the intensification, the forecasts of the precise timing and intensity levels suffer from various degrees of error. The coastal cyclones show a 5-10 hPa dependence on the western North Atlantic sea surface temperature, which is varied within a range (± 2.5℃) compatible with interannual fluctuations. The associated vertical velocities and precipitation rates show proportionately stronger dependences on the ocean temperature perturbations. The Ohio Valley blizzard, which intensified along a track 700-800 km from the coast, shows little sensitivity to ocean temperature. The effect of a shift of - 10?latitude in the position of the snow boundary is negligible in each case. The forecasts depend strongly on the model resolution, and the coarse-resolution forecasts are consistently inferior to the medium-resolution forecasts. Studies of the corresponding sensitivities of extreme cyclonic events over eastern Asia are encouraged in order to identify characteristics that are common to numerical forecasts for the two regions. 展开更多
关键词 Sensitivities of Numerical model Forecasts of Extreme Cyclone events SST
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Research on Event Handling Models of Java 被引量:1
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作者 吴跃 吴劲 《Journal of Electronic Science and Technology of China》 2004年第2期42-47,共6页
A new event-handling paradigm and its application model are proposed. The working mechanism and principle of event listener model is given in detail. Finally, the launching event mechanisms, the choosing event handlin... A new event-handling paradigm and its application model are proposed. The working mechanism and principle of event listener model is given in detail. Finally, the launching event mechanisms, the choosing event handling models and the dispatching mechanism are illustrated. 展开更多
关键词 event hanlding models event listener model delegation model DISPATCHING
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Event-driven process execution model for process virtual machine 被引量:3
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作者 WU Dong-yao WEI Jun GAO Chu-shu DOU Wen-shen 《计算机集成制造系统》 EI CSCD 北大核心 2012年第8期1675-1685,共11页
Current orchestration and choreography process engines only serve with dedicate process languages.To solve these problems,an Event-driven Process Execution Model(EPEM) was developed.Formalization and mapping principle... Current orchestration and choreography process engines only serve with dedicate process languages.To solve these problems,an Event-driven Process Execution Model(EPEM) was developed.Formalization and mapping principles of the model were presented to guarantee the correctness and efficiency for process transformation.As a case study,the EPEM descriptions of Web Services Business Process Execution Language(WS-BPEL) were represented and a Process Virtual Machine(PVM)-OncePVM was implemented in compliance with the EPEM. 展开更多
关键词 business process modeling event-driven architecture process virtual machine service orchestration process execution language
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An Emergency Scenario Reconstruction System Based on ESMM Event Situation Model
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作者 LI Shuoming CHEN Lei +1 位作者 LIU Yu CHEN Shihong 《Wuhan University Journal of Natural Sciences》 CAS CSCD 2017年第6期482-488,共7页
In order to keep decision-makers better informed with emergencies, it is useful to retrieve the user-oriented disaster relevant event information in an aggregated results list through meta-search engine. However, emer... In order to keep decision-makers better informed with emergencies, it is useful to retrieve the user-oriented disaster relevant event information in an aggregated results list through meta-search engine. However, emergent event is dynamic which makes it difficult to use fixed search word or word combinations. This paper proposes an event situation monitoring model(ESMM) event detection model, which realizes heuristic query word vector dynamic expanding by adopting emergency fuzzy scenario reasoning ontology cluster. Disaster event facet information automatic searching is discussed as an example in this paper. The experimental results show that the proposed method can increase accuracy and extra clues not supplied by commercial search engines, which can be used as a supplement information source for government and individuals. 展开更多
关键词 meta search event situation monitoring model(ESMM) model ONTOLOGY event scenario
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Cyclic Reconfigurable Flow Shop under Different Configurations Modeling and Optimization Based on Timed Event Graph
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作者 REN Si-Cheng XU De WANG Fang TAN Min 《自动化学报》 EI CSCD 北大核心 2006年第1期15-20,共6页
Based on the idea that modules are independent of machines, different combinations of modules and machines result in different configurations and the system performances differ under different configurations, a kind o... Based on the idea that modules are independent of machines, different combinations of modules and machines result in different configurations and the system performances differ under different configurations, a kind of cyclic reconfigurable flow shops are proposed for the new manufacturing paradigm-reconfigurable manufacturing system. The cyclic reconfigurable flow shop is modeled as a timed event graph. The optimal configuration is defined as the one under which the cyclic reconfigurable flow shop functions with the minimum cycle time and the minimum number of pallets. The optimal configuration, the minimum cycle time and the minimum number of pallets can be obtained in two steps. 展开更多
关键词 循环流程 制造业 时间事件 建模 优化设计
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Threshold autoregression models for forecasting El Nino events
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作者 Pu Shuzhen and Yu Huiling First Institute of Oceanography, State Oceanic Administration, Qingdao, China 《Acta Oceanologica Sinica》 SCIE CAS CSCD 1990年第1期61-67,共7页
-In this paper, monthly mean SST data in a large area are used. After the spacial average of the data is carried out and the secular monthly means are substracted, a time series (Jan. 1951-Dec. 1985) of SST anomalies ... -In this paper, monthly mean SST data in a large area are used. After the spacial average of the data is carried out and the secular monthly means are substracted, a time series (Jan. 1951-Dec. 1985) of SST anomalies of the cold tongue water area in the eastern tropical Pacific Ocean is obtained. On the basis of the time series, an autoregression model, a self-exciting threshold autoregression model and an open loop autoregression model are developed respectively. The interannual variations are simulated by means of those models. The simulation results show that all the three models have made very good hindcasting for the nine El Nino events since 1951. In order to test the reliability of the open loop threshold model, extrapolated forecast was made for the period of Jan. 1986-Feb. 1987. It can be seen from the forecasting that the model could forecast well the beginning and strengthening stages of the recent El Nino event (1986-1987). Correlation coefficients of the estimations to observations are respectively 0. 84, 0. 88 and 0. 89. It is obvious that all the models work well and the open loop threshold one is the best. So the open loop threshold autoregression model is a useful tool for monitoring the SSTinterannual variation of the cold tongue water area in the Eastern Equatorial Pacific Ocean and for estimating the El Nino strength. 展开更多
关键词 Nino EI SSTA Threshold autoregression models for forecasting El Nino events EL
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Rainfall-runoff modeling for storm events in a coastal forest catchmen t using neural networks
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作者 WANG Yi HE Bin 《成都理工大学学报(自然科学版)》 CAS CSCD 北大核心 2008年第1期68-73,共6页
The process of transformation of rainfall into runoff over a catchment is very complex and highly nonlinear and exhibits both tempor al and spatial variabilities. In this article, a rainfall-runoff model using th e ar... The process of transformation of rainfall into runoff over a catchment is very complex and highly nonlinear and exhibits both tempor al and spatial variabilities. In this article, a rainfall-runoff model using th e artificial neural networks (ANN) is proposed for simula ting the runoff in storm events. The study uses the data from a coa stal forest catchment located in Seto Inland Sea, Japan. This article studies the accuracy of the short-term rainfall forecast obta ined by ANN time-series analysis techniques and using antecedent rainfa ll depths and stream flow as the input information. The verification results from the proposed model indicate that the approach of ANN rai nfall-runoff model presented in this paper shows a reasonable agreement in rainfall-runoff modeling with high accuracy. 展开更多
关键词 降雨径流模型 暴风雨 沿海林 集水 神经网络
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Qualitative analysis for state/event fault trees using formal model checking 被引量:3
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作者 JIANG Quan ZHU Chunling WANG Siqi 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2019年第5期959-973,共15页
A state/event fault tree(SEFT)is a modeling technique for describing the causal chains of events leading to failure in software-controlled complex systems.Such systems are ubiquitous in all areas of everyday life,and ... A state/event fault tree(SEFT)is a modeling technique for describing the causal chains of events leading to failure in software-controlled complex systems.Such systems are ubiquitous in all areas of everyday life,and safety and reliability analyses are increasingly required for these systems.SEFTs combine elements from the traditional fault tree with elements from state-based techniques.In the context of the real-time safety-critical systems,SEFTs do not describe the time properties and important timedependent system behaviors that can lead to system failures.Further,SEFTs lack the precise semantics required for formally modeling time behaviors.In this paper,we present a qualitative analysis method for SEFTs based on transformation from SEFT to timed automata(TA),and use the model checker UPPAAL to verify system requirements’properties.The combination of SEFT and TA is an important step towards an integrated design and verification process for real-time safety-critical systems.Finally,we present a case study of a powerboat autopilot system to confirm our method is viable and valid after achieving the verification goal step by step. 展开更多
关键词 state/event fault tree (SEFT) TIMED AUTOMATA (TA) model transformation safety analysis
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Multiple linear regression models of urban runoff pollutant load and event mean concentration considering rainfall variables 被引量:28
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作者 Marla C.Maniquiz Soyoung Lee Lee-Hyung Kim 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2010年第6期946-952,共7页
Rainfall is an important factor in estimating the event mean concentration (EMC) which is used to quantify the washed-off pollutant concentrations from non-point sources (NPSs). Pollutant loads could also be calcu... Rainfall is an important factor in estimating the event mean concentration (EMC) which is used to quantify the washed-off pollutant concentrations from non-point sources (NPSs). Pollutant loads could also be calculated using rainfall, catchment area and runoff coefficient. In this study, runoff quantity and quality data gathered from a 28-month monitoring conducted on the road and parking lot sites in Korea were evaluated using multiple linear regression (MLR) to develop equations for estimating pollutant loads and EMCs as a function of rainfall variables. The results revealed that total event rainfall and average rainfall intensity are possible predictors of pollutant loads. Overall, the models are indicators of the high uncertainties of NPSs; perhaps estimation of EMCs and loads could be accurately obtained by means of water quality sampling or a long term monitoring is needed to gather more data that can be used for the development of estimation models. 展开更多
关键词 event mean concentration (EMC) multiple linear regression model LOAD non-point sources RAINFALL urban runoff
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Quasi-periodic events on structured earthquake models
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作者 Bin-Quan Li Zhi-Xi Wu Sheng-Jun Wang 《Chinese Physics B》 SCIE EI CAS CSCD 2019年第9期50-56,共7页
There has been much interest in studying quasi-periodic events on earthquake models.Here we investigate quasiperiodic events in the avalanche time series on structured earthquake models by the analysis of the autocorr... There has been much interest in studying quasi-periodic events on earthquake models.Here we investigate quasiperiodic events in the avalanche time series on structured earthquake models by the analysis of the autocorrelation function and the fast Fourier transform.For random spatial earthquake models, quasi-periodic events are robust and we obtain a simple rule for a period that is proportional to the choice of unit time and the dissipation of the system.Moreover, computer simulations validate this rule for two-dimensional lattice models and cycle graphs, but our simulation results also show that small-world models, scale-free models, and random rule graphs do not have periodic phenomena.Although the periodicity of avalanche does not depend on the criticality of the system or the average degree of the system or the size of the system,there is evidence that it depends on the time series of the average force of the system. 展开更多
关键词 QUASI-PERIODIC event SELF-ORGANIZED CRITICALITY EARTHQUAKE model
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A Study on the Evolution of Mechanism of Infectious Disease Analysis Model of Event Using Micro-Blog Platform 被引量:1
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作者 Haiying Ma 《Social Networking》 2015年第3期96-102,共7页
After the occurrence of unexpected group events of network, the relevant opinion information will spread rapidly through micro-blog, and the negative public opinion information will aggravate the unexpected the group ... After the occurrence of unexpected group events of network, the relevant opinion information will spread rapidly through micro-blog, and the negative public opinion information will aggravate the unexpected the group events to upgrade and expand the scope of harm. It is difficult to deal. So public opinion control is very important. In this paper, we establish an influence model for spreading of public opinion based on SIR model. Through the political analysis, this paper finds that the network group events will subside, but the influence scope, time and ability of event cannot be ignored. As a result of this study, the corresponding strategies are put forward in this paper. 展开更多
关键词 Micro-Blog Group events of Network PUBLIC OPINION Control SIR model
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Libevent与现代事件驱动库:I/O多路复用技术及性能比较研究 被引量:1
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作者 陆栋斌 《现代计算机》 2024年第17期44-48,54,共6页
通过对Libevent中事件处理模型和I/O多路复用技术的深入研究,提供了对于构建高效、稳定网络应用的全面认识。在“事件处理模型”一节,详细讨论了Libevent的事件机制、回调函数和事件循环,揭示了其非阻塞环境下高效处理并发事件的机制。... 通过对Libevent中事件处理模型和I/O多路复用技术的深入研究,提供了对于构建高效、稳定网络应用的全面认识。在“事件处理模型”一节,详细讨论了Libevent的事件机制、回调函数和事件循环,揭示了其非阻塞环境下高效处理并发事件的机制。同时,在“I/O多路复用技术”一节,介绍了Libevent支持的多种技术,并探讨了选择合适技术的关键因素,能够根据具体需求灵活应用。“实例分析”一节通过项目实例的讲解,提供了在实际项目中应用Libev⁃ent的实用指南,帮助更好地应对网络通信的挑战。 展开更多
关键词 Libevent 事件处理模型 I/O多路复用技术 非阻塞
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Test of newly developed conceptual hydrological model for simulation of rain-on-snow events in forested watershed 被引量:1
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作者 Si-min QU Han LIU +3 位作者 Yan-ping CUI Peng SHI Wei-min BAO Zhong-bo YU 《Water Science and Engineering》 EI CAS CSCD 2013年第1期31-43,共13页
A conceptual hydrological model that links the Xin'anjiang hydrological model and a physically based snow energy and mass balance model, described as the XINSNOBAL model, was developed in this study for simulating ra... A conceptual hydrological model that links the Xin'anjiang hydrological model and a physically based snow energy and mass balance model, described as the XINSNOBAL model, was developed in this study for simulating rain-on-snow events that commonly occur in the Pacific Northwest of the United States. The resultant model was applied to the Lookout Creek Watershed in the H. J. Andrews Experimental Forest in the western Cascade Mountains of Oregon, and its ability to simulate streamflow was evaluated. The simulation was conducted at 24-hour and one-hour time scales for the period of 1996 to 2005. The results indicated that runoffand peak discharge could be underestimated if snowpack accumulation and snowmelt under rain-on-snow conditions were not taken into account. The average deterministic coefficient of the hourly model in streamflow simulation in the calibration stage was 0.837, which was significantly improved over the value of 0.762 when the Xin'anjiang model was used alone. Good simulation performance of the XINSNOBAL model in the WS 10 catchment, using the calibrated parameter of the Lookout Creek Watershed for proxy-basin testing, demonstrates that transplanting model parameters between similar watersheds can orovide a useful tool for discharge forecastin~, in un^au^ed basins. 展开更多
关键词 Xin 'anjiang model snow energy and mass balance model rain-on-snow event H. J.Andrews Experimental Forest
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