期刊文献+
共找到8篇文章
< 1 >
每页显示 20 50 100
Multiple Auxiliary Information Based Deep Model for Collaborative Filtering 被引量:1
1
作者 Lin Yue Xiao-Xin Sun +2 位作者 Wen-Zhu Gao Guo-Zhong Feng Bang-Zuo Zhang 《Journal of Computer Science & Technology》 SCIE EI CSCD 2018年第4期668-681,共14页
With the ever-growing dynamicity, complexity, technique is proposed and becomes one of the most effective and volume of information resources, the recommendation techniques for solving the so-called problem of informa... With the ever-growing dynamicity, complexity, technique is proposed and becomes one of the most effective and volume of information resources, the recommendation techniques for solving the so-called problem of information overload. Traditional recommendation algorithms, such as collaborative filtering based on the user or item, only measure the degree of similarity between users or items with single criterion, i.e., ratings. According to the experience of previous studies, single criterion cannot accurately measure the similarity between user preferences or items. In recent years, the application of deep learning techniques has gained significant momentum in recommender systems for better understanding of user preferences, item characteristics, and historical interactions. In this work, we integrate plot information as auxiliary information into the denoising autoencoder (DAE), called SemRe-DCF, which aims at learning semantic representations of item descriptions and succeeds in capturing fine-grained semantic regularities by using vector arithmetic to get better rating prediction. The results manifest that the proposed method can effectively improve the accuracy of prediction and solve the cold start problem. 展开更多
关键词 semantic representation plot information denoising autoencoder collaborative filtering auxiliary information
原文传递
Semiparametric Likelihood-based Inference for Censored Data with Auxiliary Information from External Massive Data Sources
2
作者 Yue-xin FANG Yong ZHOU 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2020年第3期642-656,共15页
Published auxiliary information can be helpful in conducting statistical inference in a new study.In this paper,we synthesize the auxiliary information with semiparametric likelihood-based inference for censoring data... Published auxiliary information can be helpful in conducting statistical inference in a new study.In this paper,we synthesize the auxiliary information with semiparametric likelihood-based inference for censoring data with the total sample size is available.We express the auxiliary information as constraints on the regression coefficients and the covariate distribution,then use empirical likelihood method for general estimating equations to improve the efficiency of the interested parameters in the specified model.The consistency and asymptotic normality of the resulting regression parameter estimators established.Also numerical simulation and application with different supposed conditions show that the proposed method yields a substantial gain in efficiency of the interested parameters. 展开更多
关键词 auxiliary information Massive data Censored data Empirical likelihood Estimation equations
原文传递
Distribution Estimation with Smoothed Auxiliary Information
3
作者 Xu Liu Ahmad Ishfaq 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2011年第1期167-176,共10页
Distribution estimation is very important in order to make statistical inference for parameters or its functions based on this distribution. In this work we propose an estimator of the distribution of some variable wi... Distribution estimation is very important in order to make statistical inference for parameters or its functions based on this distribution. In this work we propose an estimator of the distribution of some variable with non-smooth auxiliary information, for example, a symmetric distribution of this variable, A smoothing technique is employed to handle the non-differentiable function. Hence, a distribution can be estimated based on smoothed auxiliary information. Asymptotic properties of the distribution estimator are derived and analyzed. The distribution estimators based on our method are found to be significantly efficient than the corresponding estimators without these auxiliary information. Some simulation studies are conducted to illustrate the finite sample performance of the proposed estimators. 展开更多
关键词 auxiliary information Empirical likelihood Estimating equations Smoothed estimating function Symmetric distribution
原文传递
Sampling strategies for estimating forest cover from remote sensing-based two-stage inventories
4
作者 Piermaria Corona Lorenzo Fattorini Maria Chiara Pagliarella 《Forest Ecosystems》 SCIE CSCD 2015年第3期208-219,共12页
Background: Remote sensing-based inventories are essential in estimating forest cover in tropical and subtropical countries, where ground inventories cannot be performed periodically at a large scale owing to high cos... Background: Remote sensing-based inventories are essential in estimating forest cover in tropical and subtropical countries, where ground inventories cannot be performed periodically at a large scale owing to high costs and forest inaccessibility(e.g. REDD projects) and are mandatory for constructing historical records that can be used as forest cover baselines. Given the conditions of such inventories, the survey area is partitioned into a grid of imagery segments of pre-fixed size where the proportion of forest cover can be measured within segments using a combination of unsupervised(automated or semi-automated) classification of satellite imagery and manual(i.e. visual on-screen)enhancements. Because visual on-screen operations are time expensive procedures, manual classification can be performed only for a sample of imagery segments selected at a first stage, while forest cover within each selected segment is estimated at a second stage from a sample of pixels selected within the segment. Because forest cover data arising from unsupervised satellite imagery classification may be freely available(e.g. Landsat imagery)over the entire survey area(wall-to-wall data) and are likely to be good proxies of manually classified cover data(sample data), they can be adopted as suitable auxiliary information.Methods: The question is how to choose the sample areas where manual classification is carried out. We have investigated the efficiency of one-per-stratum stratified sampling for selecting segments and pixels, where to carry out manual classification and to determine the efficiency of the difference estimator for exploiting auxiliary information at the estimation level. The performance of this strategy is compared with simple random sampling without replacement.Results: Our results were obtained theoretically from three artificial populations constructed from the Landsat classification(forest/non forest) available at pixel level for a study area located in central Italy, assuming three levels of error rates of the unsupervised classification of satellite imagery. The exploitation of map data as auxiliary information in the difference estimator proves to be highly effective with respect to the Horvitz-Thompson estimator,in which no auxiliary information is exploited. The use of one-per-stratum stratified sampling provides relevant improvement with respect to the use of simple random sampling without replacement.Conclusions: The use of one-per-stratum stratified sampling with many imagery segments selected at the first stage and few pixels within at the second stage- jointly with a difference estimator- proves to be a suitable strategy to estimate forest cover by remote sensing-based inventories. 展开更多
关键词 Spatially balanced sampling auxiliary information
下载PDF
A New Regression Type Estimator and Its Application in Survey Sampling
5
作者 M. Zahid Hasan M. Sultana +2 位作者 K. Fatema Md. Ali Hossain M. Murad Hossain 《Open Journal of Statistics》 2020年第6期1010-1019,共10页
In the present time, a large number of modified estimators have been proposed by authors to obtain efficiency. In this study, we suggested an alternative regression type estimator for estimating finite population mean... In the present time, a large number of modified estimators have been proposed by authors to obtain efficiency. In this study, we suggested an alternative regression type estimator for estimating finite population mean</span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> when there is either </span><span style="font-family:Verdana;">a </span><span style="font-family:Verdana;">positive or negative correlation between study variables and auxiliary variables. We obtained bias and mean square error equation of the proposed estimator ignoring the first</span><span style="font-family:Verdana;">-</span><span style="font-family:Verdana;">order approximation and found the theoretical conditions that make proposed estimator more efficient than simple random sampling mean estimator, product estimator and ratio estimator. In addition, these conditions are supported by a numerical example and it has been concluded that the proposed estimator performed better comparing with the usual simple random sampling mean estimator, ratio estimator and product estimator. 展开更多
关键词 auxiliary information BIAS EFFICIENCY Mean Square Error Product and Ratio Estimator
下载PDF
Local Polynomial Regression Estimator of the Finite Population Total under Stratified Random Sampling: A Model-Based Approach
6
作者 Charles K. Syengo Sarah Pyeye +1 位作者 George O. Orwa Romanus O. Odhiambo 《Open Journal of Statistics》 2016年第6期1085-1097,共13页
In this paper, auxiliary information is used to determine an estimator of finite population total using nonparametric regression under stratified random sampling. To achieve this, a model-based approach is adopted by ... In this paper, auxiliary information is used to determine an estimator of finite population total using nonparametric regression under stratified random sampling. To achieve this, a model-based approach is adopted by making use of the local polynomial regression estimation to predict the nonsampled values of the survey variable y. The performance of the proposed estimator is investigated against some design-based and model-based regression estimators. The simulation experiments show that the resulting estimator exhibits good properties. Generally, good confidence intervals are seen for the nonparametric regression estimators, and use of the proposed estimator leads to relatively smaller values of RE compared to other estimators. 展开更多
关键词 Sample Surveys Stratified Random Sampling auxiliary information Local Polynomial Regression Model-Based Approach Nonparametric Regression
下载PDF
Domain estimation under informative linkage
7
作者 Ray Chambers Nicola Salvati +1 位作者 Enrico Fabrizi Andrea Diniz da Silva 《Statistical Theory and Related Fields》 2019年第2期90-102,共13页
A standard assumption when modelling linked sample data is that the stochastic properties of the linking process and process underpinning the population values of the response variable are independent of one another.T... A standard assumption when modelling linked sample data is that the stochastic properties of the linking process and process underpinning the population values of the response variable are independent of one another.This is often referred to as non-informative linkage.But what if linkage errors are informative?In this paper,we provide results from two simulation experiments that explore two potential informative linking scenarios.The first is where the choice of sample record to link is dependent on the response;and the second is where the probability of correct linkage is dependent on the response.We focus on the important and widely applicable problem of estimation of domain means given linked data,and provide empirical evidence that while standard domain estimation methods can be substantially biased in the presence of informative linkage errors,an alternative estimation method,based on a Gaussian approximation to a maximum likelihood estimator that allows for non-informative linkage error,performs well. 展开更多
关键词 Non-deterministic data linkage exchangeable linkage errors informative sampling auxiliary information domain estimation maximum likelihood
原文传递
Knowledge-driven decision analytics for commercial banking
8
作者 K.S.Law Fu-Lai Chung 《Journal of Management Analytics》 EI 2020年第2期209-230,共22页
Although the corporate relationship manager seems to be the key enabler in commercial banking,the personal relationship sales model is not a sustainable model for the paradigm shift in digital financial markets.In thi... Although the corporate relationship manager seems to be the key enabler in commercial banking,the personal relationship sales model is not a sustainable model for the paradigm shift in digital financial markets.In this research,we propose a knowledge-driven decision analytics approach to improve the decision process.However,most of the corporate client documents processed in banks are not well-structured and the traditional analysis approach does not consider the document structure,which carries rich semantic information.We propose a document structure-based text representation approach with incorporating auxiliary information in the predictive analytics of unstructured data to improve the performance in the document classification task.The proposed approach significantly outperforms the traditional whole document approach which does not take into considerations of the document structure.With the proposed approach,knowledge can be effectively and efficiently used for business decisions and planning to improve the competitive advantage and substantiality of banks. 展开更多
关键词 document classification information retrieval informatics document structure analysis auxiliary information
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部