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1.
利用贝叶斯置信框架推断最小二乘支持向量机模型参数并建立贝叶斯最小二乘支持向量机非线性预测模型.在推断第1层确定模型最优参数,第2层确定正则化参数,第3层确定核参数.将该模型用于某1800热连轧轧制力的预测,在预测精度和速度上都取得了较好的效果.  相似文献   

2.
开发了最小二乘支持向量机(LS-SVM)模型,并用于对烧结矿碱度进行预测.仿真结果证明,本模型能在小样本贫信息的条件下对烧结矿碱度做出比较准确的预测.此种模型具有预测精度高、所需样本少、计算简便等优点.和BP神经网络算法相比,最小二乘支持向量机算法有很好的应用前景和推广价值.  相似文献   

3.
基于支持向量机的连铸板坯表面温度预测   总被引:1,自引:1,他引:0  
提出了一种最小二乘支持向量机的连铸板坯表面温度预测新模型.以中间罐温度、拉速、二冷水量等主要工艺因素为输入,连铸坯表面温度为输出,通过最小二乘支持向量机模型拟合输入与输出之间的复杂非线性函数关系.以现场采集的连铸生产工艺数据为样本对模型进行学习训练,用训练好的模型预测在一定工艺条件下板坯的表面温度.实践表明该方法具有建模速度快、预测精度高、操作简便等优点,不仅克服了常规的BP预测模型的不足,而且性能优于标准支持向量机预测模型.  相似文献   

4.
为提高热连轧带钢精轧厚度预测精度,建立了通过深度置信网络(deep belief network,简称DBN)提取特征的最小二乘支持向量机回归模型(DBN-LSSVM),并且利用粒子群优化算法(particle swarm optimization,简称PSO)优化最小二乘支持向量机(least squares support vector machine,简称LSSVM)相关超参数。通过采集某热连轧带钢生产线实时现场数据,对所提出厚度预测模型进行训练和离线仿真。结果表明,基于DBN-LSSVM的预测模型具有良好的学习能力和泛化性,DBN-LSSVM模型的预测精度较传统BP算法和DBN-BP算法有显著提高,该厚度预测模型在生产实践中具有很好的应用前景。  相似文献   

5.
周胜海  查五生  王向中 《稀土》2012,33(1):61-64
基于粘结NdFeB永磁体制备工艺优化实验,建立了一个最小二乘支持向量机(LS- SVM)算法模型用于工艺参数的优化.以粘结剂含量、固化温度、固化时间以及单位压制力大小四个工艺参数为影响因数,以剩余磁感应强度Br、矫顽力Hcj;和最大磁能积(BH)m为影响对象,通过最小二乘支持向量机算法模型建立起影响因素与影响对象之间的复杂的非线形关系.针对多影响对象,提出了一种γ和σ选择算法;以均匀设计试验结果为样本进行训练,用训练好的模型进行预测.结果表明,LS - SVM模型的实验结果与预测结果吻合良好,二者相对误差很小,对比ANN模型预测结果,LS - SVM模型具有更高的精度和运算速度,具有很好的实用性.  相似文献   

6.
 针对连铸过程的结晶器液面控制问题,提出了基于最小二乘支持向量机技术的预测模型的预测控制方法。利用最小二乘支持向量机对非线性过程建立预测模型,采用非线性预测控制方法进行控制。以结晶器液面控制过程为控制对象进行仿真,仿真结果表明,最小二乘支持向量机的建模方法可以有效地建立预测模型并且具有较好的泛化能力,基于这种预测模型的预测控制具有很好的控制性能。  相似文献   

7.
支持向量机是近年发展起来的新兴人工智能技术,在分析最小二乘支持向量机(SVM)理论基础上,以某污水处理厂的氧化沟系统为对象,采用一种改进的粒子群优化算法优化支持向量机的参数.建立了基于竞争机制粒子群算法ICPSO的LSSVM的氧化沟出水水质BOD智能预测模型.并与PSO—LSSVM模型和LSSVM模型比较,研究表明,ICPSO—LSSVM模型预测准确.泛化性能好.且该模型预测结果中相对误差〈10%的样本达到90%,最大相对误差仅为10.3%,均方差MSE为0.0026,模型具有较高的精度,基本可以实现出水BOD值的在线预估。  相似文献   

8.
良好的铁水质量是铸铁性能可靠性和稳定性的保证,而铁水中硫(S)含量和硅(Si)含量是衡量铁水质量的主要指标,因此在出铁前精准获取铁水S含量和Si含量具有非常重要的意义。实验提出一种结合主成分分析(PCA)和最小二乘支持向量机(LS-SVM)模型的铁水S含量和Si含量的预测方法。将某钢厂大型高炉的在线采集数据作为研究对象,首先对影响铁水中S含量和Si含量变化因素的数据做主成分分析,求取主成分作为模型的输入变量,其次建立最小二乘支持向量机预测模型对铁水S含量和Si含量进行预测。在S含量预测过程中,正则化参数gam和核函数参数sig分别取20、700时,预测误差最小,其均方根误差为0.0012,仿真时间为0.423105s;Si含量预测过程中正则化参数gam和核函数参数sig分别取40、500时预测误差最小,均方根误差为0.0238,仿真时间为0.079522s。最后将实验结果与传统最小二乘支持向量机(LS-SVM)和结合PCA的BP神经网络预测模型(PCA+BP神经网络)的结果对比,后两组对比实验关于S含量预测的均方根误差分别为0.0015和0.0014,仿真时间分别为1.320842s和2.245967s;后两种对比实验关于Si含量预测的均方根误差分别为0.0316和0.0325,仿真时间分别为0.459671s和2.061576s。实验结果表明,实验方法更加全面地考虑了所有因素对铁水中S含量和Si含量变化的影响,具有训练时间短、预测精度高等优点。  相似文献   

9.
提出了一种基于最小二乘支持向量机在单桩竖向极限承载力预测方法,建立了单桩竖向极限承载力预测的最小二乘支持向量机模型。  相似文献   

10.
为了提高板带热连轧轧制力预测精度,建立了利用粒子群优化的混合核最小二乘支持向量机(PSOLSSVM)的预测模型,并将最小二乘支持向量机模型与传统数学模型进行组合,得到组合模型,以进一步提高预测精度。通过采集现场数据,对模型进行训练并离线仿真。结果表明,PSO-LSSVM有更强的学习能力和泛化能力,预测精度得到很大提高,该方法在实际应用中具有很大潜力。  相似文献   

11.
转炉炉壳热应力分析   总被引:5,自引:1,他引:4  
任学平  郭志强  邹家祥 《炼钢》2001,17(6):47-49
根据实际转炉建立实体模型。以有限元为手段,考虑了炉衬和炉壳材料的物性参数随温度变化的特点和炉衬与炉壳之间膨胀间隙,计算了转炉炉壳在温度载荷和炉衬膨胀压力同时作用下的热应力。所得结果可为转炉炉壳设计提供依据。  相似文献   

12.
Some theories of personality hold that an individual's perception of others is influenced by his own personality characteristics; more specifically, that a trait of low social value will be projected more into others, and that insight into the possession of these characteristics reduces this distortion. These 2 hypotheses were tested by having a group of college students rate each other (including themselves) on degree of friendliness or hostility. Agreement with group rating about self yielded the insight score. In general, the hypotheses were supported; the "friendly" Ss were most accurate in their perception of others, and insight was positively associated with accurate perception. From Psyc Abstracts 36:04:4HL16M. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

13.
The rates of infection of two methods of external ventricular drainage in use at Atkinson Morley's Hospital--namely, (a) percutaneous drainage with Rickham reservoirs and (b) tunnelled ventriculostomies--were compared in this retrospective review. Percutaneous drainage of CSF with Rickham reservoirs was associated with a 27% rate of infection as identified by positive microbiological cultures; tunnelled ventriculostomy catheters had a 10% infection rate. The difference in the infection rate between the two methods was statistically significant (P < 0.015). Other variables examined, including the age and sex of the patients and the reasons for ventricular drainage, were not associated with an increased rate of infection. Most infections from either method were caused by a coagulase negative staphylococcus. The average duration of ventricular drainage before identification of positive cultures was 5.7 days for Rickham reservoirs and 6.0 days for ventriculostomies.  相似文献   

14.
鲁迅先生一生热爱美术作品,对版画中木刻兴趣尤甚.<野草>作为其"写心之作",亦呈现出一些与木刻版画一致的审美特征:一是具有木刻版画的色彩特征,多对比、多冷色,有阴郁的美感;二是具有木刻版画的力度特征,环境描写、人物刻画处处刀锋毕现,遒劲有力,有一种"力之美".  相似文献   

15.
张兴强  叶运福 《冶金设备》2005,(6):71-72,47
针对四辊破碎机车刀架车削中存在的几个问题,详细介绍了电动车刀架的结构和工作原理,建立主要设计参数的数学表达式,并进行适当的分析。改造后,这种电动车刀架运行平稳、可靠、方便、省力,取得了预期的效果。  相似文献   

16.
17.
Cancer of the cardia is traditionally discussed with cardiac cancer of the lower portion of the esophagus and upper gastric cancer invading the esophagus, and the specific characteristics of cancer of the cardia have never been clearly defined. We reviewed the outcome of 172 patients with adenocarcinoma of the cardia who had undergone radical surgery between 1949 and 1994 in the Division of Gastrointestinal Surgery of the Cancer Institute Hospital. The centers of the tumors were located within 2 cm above and below the boundary between the esophagus and the stomach, and their longitudinal diameter was less than 8 cm. We divided the patients into an early period (1949-1979; n = 79) and a late period (1980-1994; n = 93), and focused on the historical transition. There were no differences in patient gender or histology between the two periods. However, the late period was associated with fewer cases of esophageal invasion and shorter longitudinal diameter, as the age of the population advanced. The number of advanced cancers such as the localized and infiltrative type had decreased, and early cancer and early clinical stage had become more common, but despite the fact that the number of early cancers had increased, extended dissection, such as thoracic and paraaortic lymph node dissection, was performed more frequently. By clinical stage, the long-term outcome markedly improved in Stage I patient in the late period, and tended to improve in Stage II and III patients. This appears to have been attributable to the prevention of micrometastasis by extended dissection, although the number of early cancers is another major potential cause. There were no differences in the outcome of Stage IV patients between the two periods, and further advances in multimodality therapy must be awaited. The range of resection is basically proximal gastrectomy, and if there are adequate indications, the prognosis is favorable. In view of the status of lymphatic flow and lymph node metastasis, and long-term results, lateroaortic lymph node dissection is important. Since the number of early cancer patients has been increasing, if intraabdominal recurrence is prevented, intrathoracic lymph node dissection will contribute greatly to the outcome of such patients.  相似文献   

18.
通过对焦炭在高炉内的历程及其变化规律的剖析,阐述焦炭热性能指标的意义,形象地把焦炭在高炉内的损耗分为三部分(M1,M2,M3)。指出M2对焦比及焦炭价格有一定的指导作用。  相似文献   

19.
20.
In this paper is treated the fundamental problematic of the fracture of the diaphysis of the tibia and the therapeutic results after the conservative and operative treatment are confronted. Among 518 patients with 433 open fractures and 35 with closed fractures of the diaphysis of the tibia, successful treatment of more 2/3 was obtained in the period from 1968 to 1972. Following our casuistics and literature, whose results are similar, we find out that the average total treatment of the osteosynthesis of the fracture of the diaphysis was shortened for 2,5 months depending upon the type and the localisation of the fracture. Apolied methods of the operative and conservative and conservative treatment in relation to the velocity of the medical cure as well as to the extreme anatomical-functional results are analised. We noticed that osteosynthesis, made by the intermedullary nail and the extension of the canals or by a small AO table, by the achieved stability makes conditions of immediate motions and an early rehabilitation. Because of that it gives the best functional results.  相似文献   

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