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1.
文章阐述了一种可变参数的 PI 算法,基于该算法用单片机对燃油炉炉温进行过零控制。文章给出了单片机控制的接口电路及其程序框图。  相似文献   

2.
直流电机换向火花图像监测与客观评价方法的应用   总被引:1,自引:0,他引:1  
通过对直流电机换向火花特征及现有火花监测方法的研究,提出一种新的火花监测方法:图像监测法。介绍了该方法的特点和实施要点, 提出了以火花能量和火花频度为依据的火花客观评价方法,阐述了火花短时能量等几种火花客观评价参数的数学模型。  相似文献   

3.
李鹏 《河北工业科技》2014,31(5):361-365
将运动目标从背景中准确分割出的过程中,阴影的检测和消除起着重要作用。传统的目标和阴影检测算法一般都是基于目标颜色等单特征信息,因此在很大程度上受到了场景光照条件变化的影响而导致算法的执行效果降低。提出一种基于颜色信息和纹理信息的多特征融合的混合高斯模型检测算法,可以降低由单特征检测所带来较高的误检率。其中采用了两重阴影判决方法以确定真实阴影,首先通过颜色夹角进行疑似阴影的判决,进而根据前景区域和背景区域的相似度和颜色分量差值再次判决阴影。最后通过实验对阴影检测算法进行比较,表明了本文提出算法能够对阴影进行准确消除。  相似文献   

4.
针对惯性导航系统(INS)在室内定位过程中,位移误差随时间不断积累而导致定位精度不高的问题,通过分析人行走的特征,以及行走过程中零速点的特性,提出了基于惯性导航的室内定位误差修正算法。使用最大似然估计法对加速度计和陀螺仪的输出参数进行判断,确定零速点,然后通过扩展卡尔曼滤波(EKF)算法,分别建立定位系统的状态方程和观测方程对误差进行修正。利用Matlab搭建仿真平台,对算法进行了仿真。仿真实验结果表明:改进后的零速检测算法,提高了零速点检测准确率,使位移误差得到了有效抑制,并将定位误差控制在了3%以内。改进算法对室内定位误差修正具有一定的实用价值。  相似文献   

5.
通过静态法对合水油田长6油藏水平井清防蜡剂进行筛选,研发出针对性强的清防蜡剂,并对清防蜡药剂进行了室内评价。结果表明清防蜡剂新配比为溶剂、助剂、表面活性剂的体积比为92.5%~97%、1.5%~3.75%、1.5%~3.75%,其对现场蜡样的静态溶蜡速率大于0.032 g/min(实验温度45℃),动态溶蜡速率最高为0.092 g/min,有机氯含量为0、二硫化碳含量为0,闪点满足SY/T 6300—2009《采油用清、防蜡剂通用技术条件行业标准》中Ⅱ类标准,平均防蜡率、降黏率分别为34%和33%,有效地节约了药剂成本,延长了清蜡周期。  相似文献   

6.
对铁路货车轨道衡自动称重系统的来车方向辨识,轨道衡断波处理,零点误判,接近开关故障判断等问题进行技术改进,重新编写程序,解决丢数据、亏吨问题。  相似文献   

7.
5月份以来,一方面随着燃油税问题的逐步明朗,社会经营单位囤积的油品开始大量回吐,市场供应压力增加;另一方面,随着沿海禁捕期的临近,国内油品消费逐渐步入淡季;加之全国大部分地区降水集中,部分省市出现汛情,生产、运输用油受到一定影响,致使国内油品市场供大于求,油价下滑。 6月份全国汽柴油的平均批发价格分别为3130元/吨和2860元/吨,分别比5月份下降了120元/吨左右。从油价走势看,国内成品油价格持续下滑但幅度趋缓。6月上旬和中旬成品油价格下滑幅度较大,下旬受国际油价回升的影响,国内成品油价格下滑趋缓并逐步稳定。 从油价的区域差异看,东北、西北大部分地区汽柴油批发价格水平与5月份相当;华东、西南以及华北地区市场批发价格继续下滑,同5月份相比,汽油平均下降了140元/吨,柴油平均下降了160元/吨;在汽柴油价格下降幅度最大的西南地区,汽油平均下降了150元/吨,柴油平均下降了215元/吨。从总体上看,东  相似文献   

8.
针对零价铁可以有效清除工业废水中低浓度的有机氯化物,在实验中考察了铁粉对三氯乙醛的脱氯效果,重点探讨了反应时间、三氯乙醛质量浓度、pH值等因素对脱氯率的影响。实验结果表明,还原铁粉对三氯乙醛有明显的脱氯作用,脱氯率随三氯乙醛质量浓度的减小而增大,随pH值的减小而增大,随反应时间的增加而增大。在厌氧条件下,三氯乙醛质量浓度为51.5 mg/L和103 mg/L,反应前pH=2.0,反应时间为3 h时,脱氯率可以分别达到70%和61%。脱氯机理主要是基于零价铁的还原作用。  相似文献   

9.
3月份以来,涤纶长丝平均下跌幅度多在400元/吨,少部分非主流产品的价格下跌幅度则达到600元/吨以上。由于聚酯工厂所采用的原料成本相对较高,300-500元/吨的下跌幅度对企业的影响还不算很大。先来分析PTA的情况。首先,亚洲主要PX供应商近  相似文献   

10.
每次油价调整,有关各方都不满意,概因油价调整背负的政策目标过多。在国内外因素的推动下,成品油价格上调的步子终于落下:从3月20日零时起国内汽柴油价格每吨上调600元,约合柴油上调0.51元/升,汽油上调0.44元/升,上调的幅度约  相似文献   

11.
本文依据生产理论,提出短期能源利用效率和长期能源利用效率的概念,并应用随机前沿分析方法对中国2000—2010年29个省、区、市的面板数据进行分析,估算中国的长、短期能源利用效率,实证分析了结构调整、技术进步、加强管理对长短期能源利用效率的不同影响。研究发现:①我国"十五"与"十一五"期间的短期能源利用效率大致相同,但在长期能源利用效率上,前者明显高于后者;②除东北外,国内各区域短期能源利用效率的差异较小,长期能源利用效率的差异较大;③结构调整对短期能源利用效率的影响显著,但对长期能源利用效率的影响不显著;④技术进步通过改变前沿面,可以实现能源利用效率的提升。⑤短期内,加强管理能够实现能源利用效率的提升,但强化管理对提升能源利用效率的长期效应并不显著。  相似文献   

12.
为了准确获取地铁线网短时OD(起讫点)的客流分布,从而高效协调运输能力和客运需求,结合集成学习思想构建了基于决策树模型的多时间粒度下地铁线网短时OD客流预测模型。首先利用地铁自动售检票数据分析得到线网OD客流出行的时空分布特征,引入多种时空影响因素对全网数据进行训练以及预测,其次分析了地铁线网OD客流量预测精度与时间粒度之间的关系,最后以苏州市地铁为对象进行实例分析。结果表明:相对于其他模型,研究模型不仅可以有效降低预测误差和拟合客流峰值,而且运算时间也节约了数倍,提高了地铁线网短时OD客流预测的准确性和效率。因此,所设计的模型可为地铁运营与控制系统提供重要数据,有助于运营者进行限流措施、行车计划等的制定与调整。  相似文献   

13.
Profit maximization requires that decision makers assess marginal profits. We demonstrate that decision makers often confound marginal profits with changes in average profits (e.g., changes in return‐on‐investment). This results in systematic deviations from profit maximization where decision makers forgo profit‐enhancing investments that reduce average profits or engage in loss‐enhancing investments that decrease average losses. In other words, average profit becomes an anchor by which new investments are assessed. We conduct two decision‐making experiments that show this bias and demonstrate it is pronounced when average profit data are accessible or task‐relevant. Moreover, we find within‐subject effects across experiments, which helps demonstrate the mechanism that invokes the bias. Copyright © 2013 John Wiley & Sons, Ltd.  相似文献   

14.
Short-term decision support system for maintenance task prioritization   总被引:1,自引:0,他引:1  
Maintenance operations have a direct influence on production performance in manufacturing systems. Short-term production analysis is imperative to enable manufacturing operations to optimally respond to dynamic changes in the system behavior. However, most of the conventional decision support systems for production and maintenance focus on long-term statistic analysis, which is usually not applicable to a short-term period. Maintenance task prioritization is crucial and important for short-term analysis to reduce unnecessary or improper maintenance activities, especially when availability of maintenance resources is limited. The existing methods for maintenance priority assignment are often through heuristic methods or experience, which could cause unscheduled downtime and production losses. In this paper, a short-term decision support system for maintenance task prioritization based on the system operating conditions is introduced. The impact factor for priority assignment is obtained theoretically. A case study based on the simulation of an automotive assembly line illustrates that the proposed short-term system improves the system performance with a lower cost than the long-term method.  相似文献   

15.
Increased media exposure to layoffs and corporate quarterly financial reporting have created arguable a common perception—especially favored by the media itself—that the companies have been forced to improve their financial performance from quarter to quarter. Academically, the relevant question is whether companies themselves feel that they are exposed to short-term pressure to perform even if it means that they have to compromise company's long-term future. This paper studies this issue using results from a survey conducted among the 500 largest companies in Finland. The results indicate that companies in general feel moderate short-term pressure, with reasonable dispersion across firms. There seems to be a link between the degree of pressure felt, and the firm's ownership structure, i.e. we find some support for the existence of potentially short-term versus long-term owners. We also find significant ownership related differences, in line with expectations, in how such short-term pressure is reflected in actual decision variables such as the investment criteria used.  相似文献   

16.
The Vehicle-to-Grid (V2G) concept is a promising possibility for the integration of electric vehicles (EVs) into the power grid. This article presents an economic evaluation of EVs participating in the ancillary service market (primary, secondary and tertiary regulation) for the case of Germany, based on a price data set from 2011 and 2012. We examine the economic potential of nine general options to participate in the regulation market based on real-life EV specifications, connection powers and regulation energy prices. Results show that in the most profitable case a maximum average yearly profit of 730.31 € per vehicle is possible for negative regulation with payment direction TSO to provider in the secondary regulation market. Furthermore a sensitivity analysis is performed for all of the analyzed participation scenarios in order to identify crucial parameters for a possible V2G implementation. Major parameters for the successful implementation of V2G are the provided power per vehicle, the time an EV is available to the grid and the variable energy storage costs it incurs.  相似文献   

17.
针对华亭煤矿综放工作面回采期间强矿压显现的复杂性及单一监测预警技术的缺陷性,结合矿井使用的微震、声发射及钻屑监测预警技术,从多参量耦合信息的角度更加深入研究强矿压显现的前兆信息,总结出了微震预测指标与声发射能量参量、微震平均能量及次数与钻屑平均值之间的耦合特征,将其应用于强矿压的预测预报,有效提高了预测预报准确率,为强矿压防治工作提供准确的指导信息。  相似文献   

18.
企业每一项经营决策都应该进行成本效益分析。对单井临界产量的决策应采用边际收益等于边际成本的方法,短期决策时应将固定成本视为沉没成本,在决策时不予考虑。  相似文献   

19.
The reduction of energy-related CO2 emissions by more efficient enery use in medium sized companies is one of the most profitable options. However, these opportunities are scarcely realised because of many obstacles and market failures. High transaction cost and decision routines play an important role for decision making and procurement of the companies. A network concept being developed in Switzerland and covering an initial consulting of each participating company, targets for the network, regular and moderated meetings of the energy managers for mutual exchange of experiences and a yearly monitoring alleviates many of these obstacles. It doubles the energy efficiency progress relative to the average progress of industry. This network concept can be fully realised by industry itself. Average energy savings per site and year are 100,000 € and average CO2 emission reduction about 500 t CO2 per year and site. Assuming a maximum potential of 700 Networks, additional emission reductions of some 10 Mio. t CO2 seem to be possible in Germany by 2020. A network management system for consulting engineers and moderators allows a minimum performance standard of how to start and operate those efficiency networks.  相似文献   

20.
针对分布式入侵检测在当今网络安全中发挥着越来越重要的角色,将数据融合技术引入到入侵检测系统中,提出了基于数据融合的分布式入侵检测系统设计方案,描述了分布式检测和决策融合的结构设计,讨论了数据融合决策问题的数学模型,运用理论推理论证了融合决策处理的可靠性。分析比对实验表明,该系统降低了入侵检测系统的虚警率,提高了检测率。  相似文献   

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