关于中国未来强震的长期预测     

刘承昌  郭广猛 《南阳师范学院学报》2011,10(12):56-58

通过研究中国的长时间地震序列,发现在过去700年中存在有明显的44年周期．利用这一周期进行预测的话,可以很好地计算出唐山地震和汶川地震的发震年份．同时利用该周期预测了未来几年国内强震的发震时间,研究认为2015年我国可能发生强烈地震．  相似文献   

江苏省用电量的灰色预测模型     

丁玲 《鸡西大学学报》2011,11(9):52-53

本文应用灰色预测法对江苏省用电量进行预测。通过对2004———2009年江苏省用电量原始数据进行生成处理来寻找系统的规律,生成有较强规律性的数据序列,然后建立相应的微分方程模型,从而预测用电量的未来发展趋势,并通过残差修正模型使得模型的精确程度有所提高。  相似文献   

灰色系统理论在统计分析与预测中的应用     

孙锡  王宪杰 《宁波职业技术学院学报》2008,12(5):30-33

根据山东统计数据信息,以山东省农村居民收入支出为例,应用灰色系统理论建立农村住户人均收入和支出的时间（1999—2006年）序列模型,分析收入和支出的内在关系和变化趋势,给出了GM（1,1）模型的实现方法。通过对预测结果的检验,证明灰色GM（1,1）模型具有准确性高、拟合效果好的特点。  相似文献   

Bovine TMEM95 gene: Polymorphisms detecting in five Chinese indigenous cattle breeds and their association with growth traits     

《Electronic Journal of Biotechnology》2021

BackgroundTransmembrane protein 95 (TMEM95) plays a role in male fertility. Previous studies showed that genes with a significant impact on reproductive traits can also affect the growth traits of livestock. Thus, we speculated that the genetic variation of TMEM95 gene may have effects on growth traits of cattle.ResultsTwo SNPs were genotyped. The rs136174626 and rs41904693 were in the intron 4 and 3′-untranslated region, respectively. The linkage disequilibrium analysis illustrated that these two loci were not linked. The rs136174626 was associated with six growth traits of Nanyang cattle, four traits of Luxi cattle, and three traits of Ji’an cattle. For rs41904693 locus, the GG individuals had greater body height and abdominal girth in Ji’ an cattle than TT and TG individuals. In Jinnan cattle, GG and TT individuals had greater body height, height at hip cross, body length, and heart girth than TG individuals. The potential splice site prediction results suggest that the rs136174626 may influence the splicing efficiency of TMEM95, and the miRNA binding site prediction results showed that the rs41904693 may influence the expression of TMEM95 by affecting the binding efficiency of Bta-miR-1584 and TMEM95 3′-UTR.ConclusionsThe findings of the study suggested that the two SNPs in TMEM95 could be a reliable basis for molecular breeding in cattle.How to cite: Guo X, Zhang S, Yang H, et al. Bovine TMEM95 gene: Polymorphisms detecting in five Chinese indigenous cattle breeds and their association with growth traits. Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.03.004  相似文献   

国外公司财务困境预测研究进展评述   总被引：7，自引：0，他引：7  

王满玲  杨德礼 《预测》2004,23(6):15-20

国外公司财务困境预测研究在证券投资、信用风险管理、审计决策和公司财务管理中开始扮演越来越重要的角色。本文概述了国外公司财务困境预测模型的研究进展情况；基于建模主要环节和实证研究结果，系统地分析了其中关键问题的研究进展；依据该研究应用工程化的趋势，提出了需要进一步研究解决的问题。  相似文献   

融合文献知识聚类和复杂网络的关键技术识别方法研究     

王燕鹏  韩涛  陈芳 《图书情报工作》2020,64(16):105-113

[目的/意义] 立足情报研究视角,提出一套科学有效且可复用推广的关键技术识别方法,以期为国家、地区、企业和创新机构发现、部署、推动关键技术研发前瞻性布局提供情报支撑。[方法/过程] 在关键技术类型及概念界定的基础上,利用文献知识聚类识别热点技术,以各项热点技术为节点构建复杂网络,通过节点二次聚类和可视化方法展现技术结构网络,采用结构洞理论分析网络和节点特性,以此遴选共性技术;利用链路预测方法,预测技术结构网络中的缺失边产生连接的可能性,分析热点技术交叉融合促进创新技术形成的现象,以此识别潜在新兴技术。[结果/结论] 以智能制造领域为例开展关键技术识别的实证研究,通过国家权威规划文件对比和文献资料调研,初步验证方法的可操作性和有效性。  相似文献   

网络表示学习在学者科研合作预测中的应用研究     

林原  王凯巧  刘海峰  许侃  丁堃  孙晓玲 《情报学报》2020,39(4):367-373

在大数据环境下,科研合作是提高科研水平、促进科研产出的重要途径。如何在浩如烟海的学者、机构、领域信息中准确地找到与自身研究方向相近的合作对象是近年来科研合作预测的研究重点。本文通过科学学领域科学文献的记录数据,构建作者-作者、机构-机构、作者-机构、作者-关键词、机构-关键词的共现网络,接着通过网络表示方法学习作者、机构、关键词在所处网络中的语境信息,将信息实体表示成相同空间的低维稠密向量,最后根据表示向量的相似度计算实现合作对象、合作领域挖掘。通过网络表示学习方法能实现多种异质信息融合,定量计算各信息实体间的关联强度,可以很好地捕捉科研网络中学者-学者、学者-机构、学者-关键词的关系,准确地为学者挖掘潜在合作者、合作机构和关键词。  相似文献   

Predicting the citation counts of individual papers via a BP neural network     

《Journal of Informetrics》2020,14(3):101039

Predicting the citation counts of academic papers is of considerable significance to scientific evaluation. This study used a four-layer Back Propagation (BP) neural network model to predict the five-year citations of 49,834 papers in the library, information and documentation field indexed by the CSSCI database and published from 2000 to 2013. We extracted six paper features, two journal features, nine author features, eight reference features, and five early citation features to make the prediction. The empirical experiments showed that the performance of the BP neural network is significantly better than those of the six baseline models. In terms of the prediction effect, the accuracy of the model at predicting infrequently cited papers was higher than that for frequently cited ones. We determined that five essential features have significant effects on the prediction performance of the model, i.e., ‘citations in the first two years’, ‘first-cited age’, ‘paper length’, ‘month of publication’, and ‘self-citations of journals’, and the other features contribute only slightly to the prediction.  相似文献   

Predicting scientific research trends based on link prediction in keyword networks     

《Journal of Informetrics》2020,14(4):101079

The rapid development of scientific fields in this modern era has raised the concern for prospective scholars to find a proper research field to conduct their future studies. Thus, having a vision of future could be helpful to pick the right path for doing research and ensuring that it is worth investing in. In this study, we use article keywords of computer science journals and conferences, assigned by INSPEC controlled indexing, to construct a temporal scientific knowledge network. By observing keyword networks snapshots over time, we can utilize the link prediction methods to foresee the future structures of these networks. We use two different approaches for this link prediction problem. First, we have utilized three topology-based link prediction algorithms, two of which are commonly used in literature. We have also proposed a third algorithm based on nodes (keywords) clustering coefficient, their centrality measures like eigenvector centrality, and nodes community information. Then, we used nodes topological features and the outputs of aforementioned topology-based link prediction algorithms as features to feed five machine learning link prediction algorithms (SVM, Random Forest Classifier, K-Nearest Neighbors, Gaussian Naïve Bayes, and Multinomial Naïve Bayes). All tested predictors have shown considerable performance and their results are discussed in this paper.  相似文献   

Comparative study of response surface designs with errors-in-variables model     

何桢  方俊涛 《天津大学学报(英文版)》2011,17(2):146-150

This paper investigates the scaled prediction variances in the errors-in-variables model and compares the performance with those in classic model of response surface designs for three factors.The ordinary least squares estimators of regression coefficients are derived from a second-order response surface model with errors in variables.Three performance criteria are proposed.The first is the difference between the empirical mean of maximum value of scaled prediction variance with errors and the maximum value of scaled prediction variance without errors.The second is the mean squared deviation from the mean of simulated maximum scaled prediction variance with errors.The last performance measure is the mean squared scaled prediction variance change with and without errors.In the simulations,1 000 random samples were performed following three factors with 20 experimental runs for central composite designs and 15 for Box-Behnken design.The independent variables are coded variables in these designs.Comparative results show that for the low level errors in variables,central composite face-centered design is optimal;otherwise,Box-Behnken design has a relatively better performance.  相似文献