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感应电机预测功率控制器设计与调优策略
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作者 王锋 潘莹月 +1 位作者 林立松 张祯滨 《电气工程学报》 CSCD 2023年第1期24-31,共8页
近年来,中国正持续大规模发展交通产业多领域的电气化,由此对驱动装备提出了更高的要求。为适配新型运载工具的新需求,应用先进控制策略是一个重要方面。与其他控制策略相比,预测功率控制不需要代价函数权系数和检测转子位置角,是一种... 近年来,中国正持续大规模发展交通产业多领域的电气化,由此对驱动装备提出了更高的要求。为适配新型运载工具的新需求,应用先进控制策略是一个重要方面。与其他控制策略相比,预测功率控制不需要代价函数权系数和检测转子位置角,是一种潜力突出的感应电机控制策略。为了便于感应电机预测功率控制策略的推广与应用,提出一种预测功率控制调优策略。该策略首先建立了电机转速环和磁链环控制模型,然后推导出相应的离散域传递函数,在此基础之上,给出基于采样频率、期望带宽和电机参数的PI控制参数设计方法。最后的仿真结果证明,预测功率控制不需要权系数便可实现良好的控制效果,同时,所提参数设计方法可以有效简化参数设计步骤,降低了系统设计的复杂度。 展开更多
关键词 预测功率控制 策略 PI参数 传递函数
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Java优化策略在铁路互联网售票系统中的应用研究 被引量:2
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作者 杨立鹏 王拓 +1 位作者 刘卓华 李雯 《铁路计算机应用》 2016年第8期21-25,共5页
为了使铁路互联网售票系统稳定性和高效性能够得到更好的保证,结合分布式内存数据库的系统特性和铁路互联网售票系统的业务特性,对各种Java虚拟机(JVM)内存管理策略和垃圾回收机制进行了分析和研究,以余票查询业务系统模块为例对JVM参... 为了使铁路互联网售票系统稳定性和高效性能够得到更好的保证,结合分布式内存数据库的系统特性和铁路互联网售票系统的业务特性,对各种Java虚拟机(JVM)内存管理策略和垃圾回收机制进行了分析和研究,以余票查询业务系统模块为例对JVM参数调优过程进行了简要测试和分析,测试结果表明,优化后的系统具有更好的稳定性和高效性。 展开更多
关键词 铁路互联网售票系统 分布式内存数据库 JAVA虚拟机 Java策略
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无人机定点投放问题探讨
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作者 胡盈 李涵 付丽娜 《科技视界》 2024年第11期51-54,共4页
传统的无人机一般借助于自身的.GPS.系统进行辅助,但该系统在小型无人机上进行精确定位时会存在较大误差。文章采用数学物理模型,研究了需要解决的3个关键问题:无人机飞行方向与风向不同角度情况下无人机的投放最优距离;量化无人机飞行... 传统的无人机一般借助于自身的.GPS.系统进行辅助,但该系统在小型无人机上进行精确定位时会存在较大误差。文章采用数学物理模型,研究了需要解决的3个关键问题:无人机飞行方向与风向不同角度情况下无人机的投放最优距离;量化无人机飞行的稳定性,并给出稳定性与命中精度之间的关系;为保持无人机稳定而采取的飞行姿态最优调整策略,提出了系统解决方案。 展开更多
关键词 无人机 定点投放 优调策略 数学物理模型
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基于RF-XGBoost算法的汽油辛烷值损失预测模型 被引量:2
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作者 陈亚丽 苟苗苗 +1 位作者 邵露娟 邓丹 《炼油技术与工程》 CAS 2021年第12期49-53,共5页
对某炼油企业催化裂化汽油精制脱硫装置的354个操作特征进行定性降维,得到与辛烷值损失相关的39个操作特征变量;再利用随机森林(RF)算法进行定量降维,得到28个辛烷值损失评价指标体系;最后使用极端梯度提升(XGBoost)算法及调优策略,建... 对某炼油企业催化裂化汽油精制脱硫装置的354个操作特征进行定性降维,得到与辛烷值损失相关的39个操作特征变量;再利用随机森林(RF)算法进行定量降维,得到28个辛烷值损失评价指标体系;最后使用极端梯度提升(XGBoost)算法及调优策略,建立基于RF-XGBoost算法的汽油辛烷值损失预测模型。结果表明:通过充分降维,得到的操作特征比较全面,能够作为刻画辛烷值损失的指标,并且符合企业实际优化条件,可以用于实际生产操作调控。建立的预测模型通过对相关参数调优,提高了预测精度。经过可视化分析,发现辛烷值的预测值和真实值较为接近,模型测试集的误差在0.13~0.27,决定系数约78.3%,需要进一步优化算法来提高测试集的预测精度。 展开更多
关键词 RF-XGBoost算法 汽油 辛烷值损失 预测模型 操作特征 策略
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Optimal restructuring strategies under various dynamic factors 被引量:1
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作者 MENG Qing-xuan 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2007年第6期932-938,共7页
Corporate restructuring was identified as a new industrial force that has great impact on economic values and that therefore has become central in daily financial decision making. This article investigates the optimal... Corporate restructuring was identified as a new industrial force that has great impact on economic values and that therefore has become central in daily financial decision making. This article investigates the optimal restructuring strategies under different dynamic factors and their numerous impacts on firm value. The concept of quasi-leverage is introduced and valuation models are built for corporate debt and equity under imperfect market conditions. The model’s input variables include the quasi-leverage and other firm-specific parameters, the output variables include multiple corporate security values. The restruc- turing cost is formulated in the form of exponential function, which allows us to observe the sensitivity of the variation in security values. The unified model and its analytical solution developed in this research allow us to examine the continuous changes of security values by dynamically changing the coupon rates, riskless interest rate, bankruptcy cost, quasi-leverage, personal tax rate, corporate taxes rate, transaction cost, firm risk, etc., so that the solutions provide useful guidance for financing and restructuring decisions. 展开更多
关键词 RESTRUCTURING Capital structure Financial decisions
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DPTSV:A Dynamic Priority Task Scheduling Strategy for TSS Deadlock Based on Value Evaluation 被引量:2
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作者 ZHAO Bo XIANG Shuang +1 位作者 AN Yang TAO Wei 《China Communications》 SCIE CSCD 2016年第1期161-175,共15页
This paper analyzes the threat of TCG Software Stack(TSS)/TCM Service Module(TSM) deadlock in multi-user environment such as cloud and discusses its causes and mechanism.In addition,this paper puts forward a dynamic p... This paper analyzes the threat of TCG Software Stack(TSS)/TCM Service Module(TSM) deadlock in multi-user environment such as cloud and discusses its causes and mechanism.In addition,this paper puts forward a dynamic priority task scheduling strategy based on value evaluation to handle this threat.The strategy is based on the implementation features of trusted hardware and establishes a multi-level ready queue.In this strategy,an algorithm for real-time value computing is also designed,and it can adjust the production curves of the real time value by setting parameters in different environment,thus enhancing its adaptability,which is followed by scheduling and algorithm description.This paper also implements the algorithm and carries out its performance optimization.Due to the experiment result from Intel NUC,it is shown that TSS based on advanced DPTSV is able to solve the problem of deadlock with no negative influence on performance and security in multi-user environment. 展开更多
关键词 TCG software stack/TCM service module deadlock multi-user trusted platform module real-time value
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Optimal design of coordination control strategy for distributed generation system
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作者 王爱华 Norapon Kanjanapadit 《Journal of Harbin Institute of Technology(New Series)》 EI CAS 2009年第1期51-56,共6页
This paper presents a novel design procedure for optimizing the power distribution strategy in distributed generation system. A coordinating controller, responsible to distribute the total load power request among mul... This paper presents a novel design procedure for optimizing the power distribution strategy in distributed generation system. A coordinating controller, responsible to distribute the total load power request among multiple DG units, is suggested based on the conception of hierarchical control structure in the dynamic system. The optimal control problem was formulated as a nonlinear optimization problem subject to set of constraints. The resulting problem was solved using the Kuhn-Tucker method. Computer simulation results demonstrate that the proposed method can provide better efficiency in terms of reducing total costs compared to existing methods. In addition, the proposed optimal load distribution strategy can be easily implemented in real-time thanks to the simplicity of closed-form solutions. 展开更多
关键词 distributed generation coordination control strategy Kuhn-Tucker method
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Impacts of Coordinated Traffic Signal Control Strategies and Bus Priority
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《Journal of Civil Engineering and Architecture》 2012年第1期81-92,共12页
Delay in signalized intersections may constitute a significant part of bus journey times in urban environment. Providing priority for buses at traffic signals can be an effective measure to reduce this delay. Bus prio... Delay in signalized intersections may constitute a significant part of bus journey times in urban environment. Providing priority for buses at traffic signals can be an effective measure to reduce this delay. Bus priority in Swedish urban traffic signal systems are normally coordinated with fixed time plan selection. Within this framework local traffic actuated signal timing adjustments are applied based on detector inputs aimed to reduce the number of vehicles in the dilemma zone. Active bus priority is also achieved with the aim to display green signal at the arrival of the bus to the stop line. Due to lack of knowledge of traffic performance impacts of these techniques a major research study was undertaken funded by the Swedish Road Administration. The aim was to evaluate the following control strategies using Stockholm as case study: (1) Fixed time coordination (FTC); (2) Fixed time coordination with local signal timing adjustment (FTC-LTA); (3) FTC-LTA with active bus priority (PRIBUSS); (4) Self-optimizing control (SPOT) with active bus priority. The methodologies for the study included field data collection using mobile and stationary techniques, offiine signal timing calculations with TRANSYT, microscopic simulation modeling using the HUTSIM model. The study obtained the following results: (1) Local traffic adjustment with the manual FTC reduced total delay by 1%. (2) Signal timings determined using TRANSYT reduced the average intersection delay by 9% compared to manual signal settings. (3) Local traffic adjustment reduced total delay by a further 5%. (4) Bus travel time was reduced by 11% using PRIBUSS, and 28% using SPOT. (5) Travel time for all vehicles did not increase using PRIBUSS, and was reduced by 6.5% with SPOT. Results of comparing PRIBUSS and SPOT to FTC-LTA were shown to be statistically significant. 展开更多
关键词 Bus priority traffic signals PRIBUSS SPOT FTC-LTA.
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OPTIMAL INVESTMENT AND PROPORTIONAL REINSURANCE IN THE SPARRE ANDERSEN MODEL 被引量:1
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作者 Zhibin LIANG Junyi GUO 《Journal of Systems Science & Complexity》 SCIE EI CSCD 2012年第5期926-941,共16页
From the insurer's point of view, this paper studies the optimal investment and proportional reinsurance in the Sparre Andersen model. Under the criterion of maximizing the adjustment coefficient, the authors obtain ... From the insurer's point of view, this paper studies the optimal investment and proportional reinsurance in the Sparre Andersen model. Under the criterion of maximizing the adjustment coefficient, the authors obtain the closed form expressions of the optimal strategy and the maximal adjustment coefficient, and derive the explicit expression of the ruin probability or its lower bound when the claim sizes are exponentially distributed. Some numerical examples are presented, which show the impact of model parameters on the optimal values. It can also be seen that the optimal strategy to maximize the adjustment coefficient is sometimes equivalent to those which minimize the ruin probability. 展开更多
关键词 Adjustment coefficient INVESTMENT proportional reinsurance ruin probability SparreAndersen model.
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