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试用三次指数平滑法预测传染病发病率 总被引:2,自引:0,他引:2
将 1994~ 1997年伤寒发病率数据消除季节变动后 ,运用三次指数平滑法对海安县 1998年伤寒发病率进行预测 ,取得了较好的预测效果 ,其总的相对误差为 -5 .10 %。 相似文献
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目的:掌握肿瘤科住院人数的季节变化规律,验证时间序列法在预测肿瘤科住院人数中的科学性和实用性,为及时、合理安排肿瘤病人入院,并得到及时的诊断和治疗提供科学依据。方法:以某院2002~2004年肿瘤科住院人数为依据,引用时间序列法从理论上预测2005年肿瘤科住院人数,并对3年来的肿瘤病人收治情况进行动态分析。结果:将预测值与实际完成值进行比较,结果与实际情况基本相符,显示出肿瘤科住院人数呈逐年上升趋势。结论:时间序列法预测肿瘤科住院人数结果准确、可靠,它弥补了其它预测方法的不足,说明使用时间序列法进行肿瘤科住院人数的预测,具有较强的科学性和适用性。 相似文献
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介绍了支持向量机用于时间序列预测的理论基础和遗传算法优化支持向量机参数的方法,首次把遗传算法优化参数支持向量机应用于两组实际网络流量的预测,并与BP神经网络和RBF神经网络方法进行了比较.结果表明:支持向量机相比较BP神经网络和RBF神经网络对网络流量的预测结果精度更高、性能更好.利用支持向量机预测网络流量是一种可行、有效的方法. 相似文献
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预测是人们对未来事物或不确定性事件的行为与状态做出的主观判断.社会实践证明,社会的发展,要求人们设法使工作具有预见性,对纷纭复杂的现实问题,提出科学的预测和对策.目前的预测方法很多,常用的有专家预测方法(如头脑风暴法),趋势外推法,指数平滑法,类推法,投入产出分析法,回归分析法,生长曲线法和马尔可夫链法等.从类型上分,这些方法可分为统计型、递推型和连续型,灰色预测法属于连续型.预测方法也可分为直观型预测法、时间预测法和计量模型法,这时灰色预测法属于时间预测法,并兼有直观型预测法和计量模型法的一些特点.传统的预测方法要求预测用的数据资料样本量大(一般要求50个左右),服从特殊的统计分布,按相同的发展变化规律变化. 相似文献
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目的:根据历史数据对未来3年的进口检品数量进行预测,为领导决策和业务规划提供依据。方法:采用目前较为成熟的4种预测分析模型:三次指数平滑预测法、灰色模型、一元线性回归组合预测法、差分自回归移动平均(以下简称ARIMA)模型,选择适当参数进行预测和方法评价。结果:预测2016年、2017年、2018年的进口数量分别为30544件(30327~31730件)、32844件(32616~34097件)、35144件(34905~36465件)。结论:4种分析模型中,ARIMA模型对2011年至2015年的预测结果与实际数据的偏差相对最小,预测准确度相对较高。 相似文献
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《Research in social & administrative pharmacy》2020,16(8):1095-1099
BackgroundTime series models are widely used forecasting techniques in health care for long time series and are typically built in commercial statistical packages. However, for short time series data, such as health-related quality of life (HRQoL), guidance on how to select and use appropriate time series models is lacking. This tutorial provides a step-by-step guide adopting a time series analysis framework for HRQoL forecasting.ObjectiveWe walk through a case study examining the forecasting of the effects of adjuvant endocrine therapy on the HRQoL of post-menopausal women with non-metastatic ER + breast cancer using data from the HRQoL sub-protocol of the Tamoxifen arm of the Arimidex, tamoxifen, alone or in combination (ATAC) trial.MethodsThe forecasting of HRQoL consists of four steps: 1) data extraction and accuracy check, 2) forecasting horizon definition and identification of data pattern, 3) forecasting model identification and fitting using five forecasting approaches appropriate for short time series ((i) double exponential smoothing, (ii) double moving average, (iii) fuzzy forecasting, (iv) grey forecasting, and (v) Volterra series), 4) forecasting model selection. A user-friendly visual basic for applications (VBA) Excel add-in is made available to interested users to facilitate the application of the tutorial.ResultsThe Grey method and Volterra series appeared to be good candidates to forecast the effects of adjuvant endocrine therapy on the HRQoL of post-menopausal women with non-metastatic ER + breast cancer enrolled in the ATAC trial.ConclusionIt is feasible to forecast the effects of treatments on HRQOL even when the time series is short. 相似文献
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K Matsumoto T Shomura M Shimura J Yoshida M Ito T Watanabe T Ito 《The Journal of antibiotics》1985,38(11):1487-1493
A new antibiotic SF-2185 was found active against plant pathogen, particularly the causal organisms of cucumber downy mildew and rice blast. The producing organism, strain SF-2185, is a novel actinomycete and has been identified as Dactylosporangium aurantiacum subsp. gifuense. 相似文献
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L Somerville 《Xenobiotica; the fate of foreign compounds in biological systems》1986,16(10-11):1017-1030
Of the three main groups of pesticides (insecticides, fungicides and herbicides), fungicides have probably the longest history, dating back to the accidental discovery in 1882 of Bordeaux mixture and the value of copper-based preparations for the control of vine downy mildew disease. In more recent times a wide range of fungicides have become available, including compounds with not only protectant but systemic activity, and total world-wide sales in 1983 were estimated at 2.8 billion dollars. This review attempts to summarize the current state of knowledge as it relates to the metabolism in animals and plants of examples of several of the major fungicide groups. Specifically the metabolism of maneb, mancozeb, zineb, captan, chlorothalonil, benomyl, triadimefon, triadimenol and cymoxanil are discussed. 相似文献
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Abdalla MA Win HY Islam MT von Tiedemann A Schüffler A Laatsch H 《The Journal of antibiotics》2011,64(10):655-659
In the course of our screening for anti-peronosporomycetal agents, we isolated a new compound khatmiamycin (1), together with five known metabolites, GTRI-02 (3), 4-ethyl-5-methyl-heptanamide (4), aloesaponarin II (5), LL-C10037α (6) and LL-C10037β (7) from the culture broth of a terrestrial Streptomyces sp. ANK313. The structures of these metabolites were assigned on the basis of their spectroscopic data. Khatmiamycin (1) exhibited potent motility inhibitory (100%) and lytic (83±7%) activities against zoospores of the grapevine downy mildew pathogen Plasmopara viticola at 10?μg?ml(-1), followed by compounds 5 (MIC 25?μg?ml(-1)), 7, 6, 3 in the order of decreasing activity. Khatmiamycin (1) also showed potent antibacterial activity against Staphylococcus aureus and Streptomyces viridochromogenes (Tü57) by causing inhibition zones of 11 and 14?mm diameter, respectively, at the dose of 40?μg per disk. This is the first report on motility inhibitory and lytic activities of metabolites from a terrestrial Streptomyces species against the zoospores of downy mildew pathogen P. viticola. 相似文献
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《Xenobiotica; the fate of foreign compounds in biological systems》2013,43(10-11):1017-1030
1. Of the three main groups of pesticides (insecticides, fungicides and herbicides), fungicides have probably the longest history, dating back to the accidental discovery in 1882 of Bordeaux mixture and the value of copper-based preparations for the control of vine downy mildew disease.2. In more recent times a wide range of fungicides have become available, including compounds with not only protectant but systemic activity, and total world-wide sales in 1983 were estimated at 2.8 billion dollars.3. This review attempts to summarize the current state of knowledge as it relates to the metabolism in animals and plants of examples of several of the major fungicide groups.4. Specifically the metabolism of maneb, mancozeb, zineb, captan, chlorothalonil, benomyl, triadimefon, triadimenol and cymoxanil are discussed. 相似文献
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目的 制定山东省地方习用药材海参的质量标准。方法 参照《中国药典》(2020版)相关方法对海参药材进行性状和薄层色谱(TLC)鉴别研究,测定了水分、酸不溶性灰分及浸出物的含量;通过硫酸苯酚法以葡萄糖为对照品测定海参多糖的含量;采用高效液相色谱法(HPLC)对海参药材的特征图谱进行研究。结果 不同批次海参药材的性状特征较一致;TLC斑点清晰,重复性好;海参药材中水分的质量分数为8.5% ~ 9.5%,酸不溶性灰分的质量分数为0.1% ~ 0.2%,浸出物的质量分数范围为33.6% ~ 51.7%;以葡萄糖计海参多糖的质量分数范围为0.52% ~ 0.85%;供试品色谱图中呈现的5个特征峰与对照药材参照物色谱图中的5个特征峰的保留时间相对应。结论 本研究建立的定性及定量方法操作简便、准确、稳定。可用于海参药材的质量控制。 相似文献
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了解国内外临床路径效果评价研究进展,为今后开展临床路径效果评价研究提供参考。方法:通过文献研究,总结目前国内外临床路径效果评价研究所使用的评价方法、评价指标等内容。结果:国内外研究普遍采用前后对照法或平行对照法,一部分研究采用meta分析进行效果评价;统计学上,大部分研究仅对结果进行t检验,部分研究使用回归、间断时间序列、双重差分等方法。评价指标上,多采用效率指标、效果指标、卫生经济学指标和工作量指标等4大类指标。结论:目前,国内外已经有较为成熟的临床路径效果评价体系,在评价方法和评价指标的选取上需要针对研究的问题灵活选择。 相似文献
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灰色数列预测模型在煤工尘肺预测中的应用 总被引:1,自引:1,他引:0
本文利用灰色数列预测模型对煤工尘肺年度患病人数进行了预测,同时与指数曲线模型和二次抛物线模型的预测效果进行了比较。结果表明:灰色数列预测模型外推性预测效果优于另外二种模型。 相似文献
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P. J. Goodford F. E. Norrington W. H. G. Richards L. P. Walls 《British journal of pharmacology》1973,48(4):650-654
1. Regression equations were calculated relating the observed antimalarial potencies of arylamidinoureas to their predicted physicochemical properties.2. A two-parameter equation was used to forecast the antimalarial activity of more arylamidinoureas.3. Thirteen compounds of the predicted type were synthesized, and their observed antimalarial potencies compared with the forecasts. 相似文献