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Customer Information Disclosure and Analyst Forecasts : Empirical Evidence from Analysts' Perspective 被引量:1
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作者 Rui ZHAO Weisheng JIN 《Asian Agricultural Research》 2019年第2期32-37,共6页
Based on the company's disclosure of key customer information,the impact of corporate customer concentration on analyst forecast was studied,and we further studied the impact of detailed customer names on analyst ... Based on the company's disclosure of key customer information,the impact of corporate customer concentration on analyst forecast was studied,and we further studied the impact of detailed customer names on analyst forecasts. It is found that:(i) customer concentration significantly affects the accuracy of analyst forecasts. The higher the customer concentration is,the lower the accuracy of analyst forecasts is;(ii) Voluntary disclosure of customer names can provide incremental information to analysts and mitigate the negative impact of customer concentration on the accuracy of analyst forests;(iii) further research has found that the incremental information brought by the state-owned enterprises' disclosure of the customer names to analysts is more obvious; disclosure of customer names by companies with high environmental uncertainty is more likely to be of concern to analysts; and star analysts have a higher ability to interpret customer names than non-star analysts. 展开更多
关键词 analyst forecasts CUsTOMER information DIsCLOsURE CUsTOMER concentration CORPORATE nature Environmental uncertainty
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The Quality of Analysts' Cash Flow Forecasts in China 被引量:2
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作者 Jun Yao Chenxing Meng 《中国会计与财务研究》 2014年第2期228-244,共17页
关键词 流量预测 现金流 中国 质量 测量问题 激励机制 回归测试 数据集中
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Earnings disaggregation and analysts' forecasts
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作者 Joshua G Rosette Yong-Chul Shin 《Journal of Modern Accounting and Auditing》 2010年第9期37-49,共13页
Accounting concepts dictate that separately disclosed components should contain separate useful information. This paper examines the relations between income statement components and analysts' earnings forecasts and ... Accounting concepts dictate that separately disclosed components should contain separate useful information. This paper examines the relations between income statement components and analysts' earnings forecasts and forecast errors. Regressions explaining earnings forecasts using earnings components provide a better fit than regression using just aggregate income to explain forecasts. We interpret this as consistent with the hypothesis that analysts use incremental information in components not available in aggregate income. However, additional tests based on predictability of forecast errors indicate that analysts do not incorporate all information available in components into earnings forecasts. In addition, this inefficiency appears to increase at longer forecast horizons. 展开更多
关键词 analysts earnings forecasts earnings forecast errors earnings components earnings response coefficients
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New European Union's Requirements and IFRS Practice Statement "Management Commentary": Does MD&A Disclosure Quality Affect Analysts' Forecasts?
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作者 S. Pisano F. Alvino 《Journal of Modern Accounting and Auditing》 2015年第6期283-301,共19页
The Management Discussion and Analysis (MD&A) is a mandatory document under the European Union's (EU) law. In 2003, the EU issued Directive 2003/51/EC, which broadened the information that firms have to provide ... The Management Discussion and Analysis (MD&A) is a mandatory document under the European Union's (EU) law. In 2003, the EU issued Directive 2003/51/EC, which broadened the information that firms have to provide in their MD&A, and in 2010 the International Accounting Standards Board (IASB) issued the International Financial Reporting Standards (IFRS) Practice Statement "Management Commentary", a non-binding guidance for the presentation of this document. The aim of this paper is to examine the relationship between MD&A disclosure quality and properties of analysts' forecasts. In fact, although most studies found that financial analysts mainly refer to financial statement data in forecasting earnings, there are few researches highlighting the importance of MD&A disclosures for financial analysts. On this basis, Ramnath, Rock, and Shane (2008) called for researches in order to better understand the relationship between the information really used by analysts and their forecasts. To assess the quality of MD&A disclosures, we developed a multidimensional measure on the basis of the EU requirements and the IFRS Practice Statement, and then we regressed this variable on both forecast accuracy and dispersion. The findings show that our measure of MD&A disclosure quality is significantly and positively related to forecast accuracy. We conducted other analyses in order to better understand the previous relationship and we found that, if we analyze the different information contained in the MD&A statement, financial analysts consider useful accounting and financial data in forecasting earnings. These results enhance our understanding of the role of MD&A disclosures in the wide set of information that firms provide to financial statement users. 展开更多
关键词 Management Discussion and Analysis (MD&A) Directive 2003/51/EC Intemational FinancialReporting standards (IFRs Practice statement "Management Commentary" disclosure quality analysts forecasts
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The forecasting efficiency under different selected regions by Pattern Informatics Method and seismic potential estimation in the North-South Seismic Zone
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作者 Weixi Tian Yongxian Zhang 《Earthquake Science》 2024年第4期368-382,共15页
In 2022,four earthquakes with M_(S)≥6.0 including the Menyuan M_(S)6.9 and Luding M_(S)6.8 earthquakes occurred in the North-South Seismic Zone(NSSZ),which demonstrated high and strong seismicity.Pattern Informatics(... In 2022,four earthquakes with M_(S)≥6.0 including the Menyuan M_(S)6.9 and Luding M_(S)6.8 earthquakes occurred in the North-South Seismic Zone(NSSZ),which demonstrated high and strong seismicity.Pattern Informatics(PI)method,as an effective long and medium term earthquake forecasting method,has been applied to the strong earthquake forecasting in Chinese mainland and results have shown the positive performance.The earthquake catalog with magnitude above M_(S)3.0 since 1970 provided by China Earthquake Networks Center was employed in this study and the Receiver Operating Characteristic(ROC)method was applied to test the forecasting efficiency of the PI method in each selected region related to the North-South Seismic Zone systematically.Based on this,we selected the area with the best ROC testing result and analyzed the evolution process of the PI hotspot map reflecting the small seismic activity pattern prior to the Menyuan M_(S)6.9 and Luding M_(S)6.8 earthquakes.A“forward”forecast for the area was carried out to assess seismic risk.The study shows the following.1)PI forecasting has higher forecasting efficiency in the selected study region where the difference of seismicity in any place of the region is smaller.2)In areas with smaller differences of seismicity,the activity pattern of small earthquakes prior to the Menyuan M_(S)6.9 and Luding M_(S)6.8 earthquakes can be obtained by analyzing the spatio-temporal evolution process of the PI hotspot map.3)The hotspot evolution in and around the southern Tazang fault in the study area is similar to that prior to the strong earthquakes,which suggests the possible seismic hazard in the future.This study could provide some ideas to the seismic hazard assessment in other regions with high seismicity,such as Japan,Californi,Turkey,and Indonesia. 展开更多
关键词 Luding M_(s)6.8 and Menyuan M_(s)6.9 earthquake Pattern Informatics Method North-south seismic Zone earthquake forecasting seismic activity pattern.
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Theoretical explanations to security analysts' forecast bias
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作者 ZHAO Xiao-yan 《Chinese Business Review》 2007年第5期1-4,共4页
As the representative of mature investors, security analysts' recommendations are guidance for most investors, However, a great deal of studies nearly draws the consistent conclusion, i.e. they are not as smart as we... As the representative of mature investors, security analysts' recommendations are guidance for most investors, However, a great deal of studies nearly draws the consistent conclusion, i.e. they are not as smart as we imagine, or the market doesn't trust their recommendations so much. The existence of optimistic bias in their recommendations has been supported by empirical data widely. Hence these make many papers to explore the reasons and try to give theoretical explanations. Based on prior researches, this paper mainly compares two theoretical models both based on mathematical methods. 展开更多
关键词 security analysts forecast optimistic bias earning skewness
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R/S Analysis and its Application in the Forecast of Mine Inflows 被引量:14
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作者 YANG Yong-guo YUAN Jian-fei CHEN Suo-zhong 《Journal of China University of Mining and Technology》 EI 2006年第4期425-428,共4页
In this paper, the status quo and modeling principles of R/S analysis of non-linear theory are introduced and reviewed. Given the hydro-geological conditions of the Wutongzhuang coal mine, Hurst exponents of mine infl... In this paper, the status quo and modeling principles of R/S analysis of non-linear theory are introduced and reviewed. Given the hydro-geological conditions of the Wutongzhuang coal mine, Hurst exponents of mine inflow for the main shaft, venti- lating shaft and auxiliary shaft were obtained using R/S analysis, which are 0.772 0, 0.824 7 and 0.905 1 respectively. Since all of the three Hurst exponents are larger than 0.5, it can be concluded that the trend of mine inflow are a long-term as well as persistent problem. Based on the level of duration, the shafts can be listed in decreasing order as the auxiliary shaft, the ventilation shaft and the main shaft, which appears identical with the actual situation of the mine inflow. With R/S analysis, a new method for long-term forecasting of mine inflows is provided. 展开更多
关键词 R/s analysis Wutongzhuang coal mine mine inflow forecasting Hurst exponents
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A data assimilation-based forecast model of outer radiation belt electron fluxes 被引量:2
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作者 Yuan Lei Xing Cao +3 位作者 BinBin Ni Song Fu TaoRong Luo XiaoYu Wang 《Earth and Planetary Physics》 CAS CSCD 2023年第6期620-630,共11页
Because radiation belt electrons can pose a potential threat to the safety of satellites orbiting in space,it is of great importance to develop a reliable model that can predict the highly dynamic variations in outer ... Because radiation belt electrons can pose a potential threat to the safety of satellites orbiting in space,it is of great importance to develop a reliable model that can predict the highly dynamic variations in outer radiation belt electron fluxes.In the present study,we develop a forecast model of radiation belt electron fluxes based on the data assimilation method,in terms of Van Allen Probe measurements combined with three-dimensional radiation belt numerical simulations.Our forecast model can cover the entire outer radiation belt with a high temporal resolution(1 hour)and a spatial resolution of 0.25 L over a wide range of both electron energy(0.1-5.0 MeV)and pitch angle(5°-90°).On the basis of this model,we forecast hourly electron fluxes for the next 1,2,and 3 days during an intense geomagnetic storm and evaluate the corresponding prediction performance.Our model can reasonably predict the stormtime evolution of radiation belt electrons with high prediction efficiency(up to~0.8-1).The best prediction performance is found for~0.3-3 MeV electrons at L=~3.25-4.5,which extends to higher L and lower energies with increasing pitch angle.Our results demonstrate that the forecast model developed can be a powerful tool to predict the spatiotemporal changes in outer radiation belt electron fluxes,and the model has both scientific significance and practical implications. 展开更多
关键词 Earth’s outer radiation belt data assimilation electron flux forecast model performance evaluation
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Factors Limiting the Forecast Skill of the Boreal Summer Intraseasonal Oscillation in a Subseasonal-to-Seasonal Model 被引量:1
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作者 Zheng HE Pangchi HSU +2 位作者 Xiangwen LIU Tongwen WU Yingxia GAO 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2019年第1期104-118,共15页
In this study,we evaluate the forecast skill of the subseasonal-to-seasonal(S2S)prediction model of the Beijing Climate Center(BCC)for the boreal summer intraseasonal oscillation(BSISO).We also discuss the key factors... In this study,we evaluate the forecast skill of the subseasonal-to-seasonal(S2S)prediction model of the Beijing Climate Center(BCC)for the boreal summer intraseasonal oscillation(BSISO).We also discuss the key factors that inhibit the BSISO forecast skill in this model.Based on the bivariate anomaly correlation coefficient(ACC)of the BSISO index,defined by the first two EOF modes of outgoing longwave radiation and 850-hPa zonal wind anomalies over the Asian monsoon region,we found that the hindcast skill degraded as the lead time increased.The ACC dropped to below 0.5for lead times of 11 days and longer when the predicted BSISO showed weakened strength and insignificant northward propagation.To identify what causes the weakened forecast skill of BSISO at the forecast lead time of 11 days,we diagnosed the main mechanisms responsible for the BSISO northward propagation.The same analysis was also carried out using the observations and the outputs of the four-day forecast lead that successfully predicted the observed northward-propagating BSISO.We found that the lack of northward propagation at the 11-day forecast lead was due to insufficient increases in low-level cyclonic vorticity,moistening and warm temperature anomalies to the north of the convection,which were induced by the interaction between background mean flows and BSISO-related anomalous fields.The BCC S2S model can predict the background monsoon circulations,such as the low-level southerly and the northerly and easterly vertical shears,but has limited capability in forecasting the distributions of circulation and moisture anomalies. 展开更多
关键词 BCC s2s model boreal summer intraseasonal oscillation forecast skill northward propagation
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Verification of an operational ocean circulation-surface wave coupled forecasting system for the China's seas 被引量:5
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作者 WANG Guansuo ZHAO Chang +2 位作者 XU Jiangling QIAO Fangli XIA Changshui 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2016年第2期19-28,共10页
An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation sin... An operational ocean circulation-surface wave coupled forecasting system for the seas off China and adjacent areas(OCFS-C) is developed based on parallelized circulation and wave models. It has been in operation since November 1, 2007. In this paper we comprehensively present the simulation and verification of the system, whose distinguishing feature is that the wave-induced mixing is coupled in the circulation model. In particular, with nested technique the resolution in the China's seas has been updated to(1/24)° from the global model with(1/2)°resolution. Besides, daily remote sensing sea surface temperature(SST) data have been assimilated into the model to generate a hot restart field for OCFS-C. Moreover, inter-comparisons between forecasting and independent observational data are performed to evaluate the effectiveness of OCFS-C in upper-ocean quantities predictions, including SST, mixed layer depth(MLD) and subsurface temperature. Except in conventional statistical metrics, non-dimensional skill scores(SS) is also used to evaluate forecast skill. Observations from buoys and Argo profiles are used for lead time and real time validations, which give a large SS value(more than 0.90). Besides, prediction skill for the seasonal variation of SST is confirmed. Comparisons of subsurface temperatures with Argo profiles data indicate that OCFS-C has low skill in predicting subsurface temperatures between 100 m and 150 m. Nevertheless, inter-comparisons of MLD reveal that the MLD from model is shallower than that from Argo profiles by about 12 m, i.e., OCFS-C is successful and steady in MLD predictions. Validation of 1-d, 2-d and 3-d forecasting SST shows that our operational ocean circulation-surface wave coupled forecasting model has reasonable accuracy in the upper ocean. 展开更多
关键词 operational forecast sea surface temperature mixed layer depth lead time subsurface temperature ocean circulation-surface wave coupled forecast system China's seas
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Forecasting Inflation Rate of Zambia Using Holt’s Exponential Smoothing 被引量:2
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作者 Stanley Jere Mubita Siyanga 《Open Journal of Statistics》 2016年第2期363-372,共10页
In this paper, the Holt’s exponential smoothing and Auto-Regressive Integrated Moving Average (ARIMA) models were used to forecast inflation rate of Zambia using the monthly consumer price index (CPI) data from May 2... In this paper, the Holt’s exponential smoothing and Auto-Regressive Integrated Moving Average (ARIMA) models were used to forecast inflation rate of Zambia using the monthly consumer price index (CPI) data from May 2010 to May 2014. Results show that the ARIMA ((12), 1, 0) is an adequate model which best fits the CPI time series data and is therefore suitable for forecasting CPI and subsequently the inflation rate. However, the choice of the Holt’s exponential smoothing is as good as an ARIMA model considering the smaller deviations in the mean absolute percentage error and mean square error. Moreover, the Holt’s exponential smoothing model is less complicated since you do not require specialised software to implement it as is the case for ARIMA models. The forecasted inflation rate for April and May, 2015 is 7.0 and 6.6 respectively. 展开更多
关键词 INFLATION Holt’s Exponential smoothing forecasting Consumer Price Index Mean square Error and Mean Absolute Percentage Error
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Forecasting Short Time Series with Missing Data by Means of Energy Associated to Series 被引量:2
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作者 Cristian Rodríguez Rivero Julián Pucheta +2 位作者 Sergio Laboret Daniel Patino Víctor Sauchelli 《Applied Mathematics》 2015年第9期1611-1619,共9页
In this work an algorithm to predict short times series with missing data by means energy associated of series using artificial neural networks (ANN) is presented. In order to give the prediction one step ahead, a com... In this work an algorithm to predict short times series with missing data by means energy associated of series using artificial neural networks (ANN) is presented. In order to give the prediction one step ahead, a comparison between this and previous work that involves a similar approach to test short time series with uncertainties on their data, indicates that a linear smoothing is a well approximation in order to employ a method for uncompleted datasets. Moreover, in function of the long- or short-term stochastic dependence of the short time series considered, the training process modifies the number of patterns and iterations in the topology according to a heuristic law, where the Hurst parameter H is related with the short times series, of which they are considered as a path of the fractional Brownian motion. The results are evaluated on high roughness time series from solutions of the Mackey-Glass Equation (MG) and cumulative monthly historical rainfall data from San Agustin, Cordoba. A comparison with ANN nonlinear filters is shown in order to see a better performance of the outcomes when the information is taken from geographical point observation. 展开更多
关键词 Artificial Neural Networks Rainfall forecasting Energy Associated to Time series Hurst’s Parameter
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Forecasting Oil Production in North Dakota Using the Seasonal Autoregressive Integrated Moving Average (S-ARIMA) 被引量:1
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作者 Jaesung Choi David C. Roberts EunSu Lee 《Natural Resources》 2015年第1期16-26,共11页
North Dakota’s oil production has been rapidly increasing during the past several years. The state’s oil production in March 2013 even increased to more than twice the quantity produced in March 2011, and the estima... North Dakota’s oil production has been rapidly increasing during the past several years. The state’s oil production in March 2013 even increased to more than twice the quantity produced in March 2011, and the estimated Bakken Formation reserves were reported very large compared with those of the United Arab Emirates. It eventually makes a question to us of how much oil will be able to be actually extracted with currently available technologies. To answer this question, this paper forecasts future oil development trend in North Dakota using the Seasonal Autoregressive Integrated Moving Average (S-ARIMA) model. Nonstationarity derived from a stochastic trend and the abrupt structural change of oil industry was a big potential problem, but through the Quandt Likelihood Ratio test, we found break points, which allowed us to select a model fitting period suitable for the S-ARIMA method to provide accurate statistical inference for the historical period. The seven major oil producing counties were investigated to determine whether the current oil boom was consistent across all oil fields in North Dakota. Empirical estimates show that North Dakota’s oil production will be more than double in the next five years. What we can predict with great certainty is that North Dakota’s influence over domestic and global oil supply systems will increase in the near future, especially over the next five to six years. This is good news for those who are concerned about domestic energy security in the USA. 展开更多
关键词 Bakken FORMATION forecasting NORTH Dakota OIL s-ARIMA
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Probability forecast of earthquake magnitude in Chinese mainland before A.D. 2005
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作者 王晓青 傅征祥 蒋铭 《Acta Seismologica Sinica(English Edition)》 CSCD 1996年第4期13-20,共8页
A probability forecast method of earthquake magnitude, based on the earthquake frequency magnitude relation and the model of Bernoulli′s random independent trial, is applied to the earthquake risk assessmen... A probability forecast method of earthquake magnitude, based on the earthquake frequency magnitude relation and the model of Bernoulli′s random independent trial, is applied to the earthquake risk assessment of seismic zones in China's Mainland before A.D.2005 in the paper. The forecasting results indicate that the probabilities of earthquake occurrence with magnitude 5 in seismic zones before 2005 are estimated to be over 0.7 in common and 0.8 in most zones; and from 0.5 to 0.7 with M =6; the maximum probability of earthquake occurrence with magnitude 7 is estimated at 0.858, which is also expected in Shanxi seismic zone. In west China's Mainland, earthquakes with magnitude 6 are expected to occur in most seismic zones with high probability (over 0.9 in general) ; the relatively high probabilities of earthquake occurrence (more than 0.7) with magnitude 7 are expected in the seismic zones surrounding the Qinghai Tibet plateau and south Tianshan seismic zone. A discussion about the result confidence and the relationship between the estimated probability and the possible annual rate of earthquake occurrence is made in the last part of the paper. 展开更多
关键词 probability forecast of earthquake magnitude Bernoulli′s random independent trial.
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High-precision chaotic radial basis function neural network model:Data forecasting for the Earth electromagnetic signal before a strong earthquake
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作者 Guocheng Hao Juan Guo +2 位作者 Wei Zhang Yunliang Chen David AYuen 《Geoscience Frontiers》 SCIE CAS CSCD 2022年第1期364-373,共10页
The Earth’s natural pulse electromagnetic field data consists typically of an underlying variation tendency of intensity and irregularities.The change tendency may be related to the occurrence of earthquake disasters... The Earth’s natural pulse electromagnetic field data consists typically of an underlying variation tendency of intensity and irregularities.The change tendency may be related to the occurrence of earthquake disasters.Forecasting of the underlying intensity trend plays an important role in the analysis of data and disaster monitoring.Combining chaos theory and the radial basis function neural network,this paper proposes a forecasting model of the chaotic radial basis function neural network to conduct underlying intensity trend forecasting by the Earth’s natural pulse electromagnetic field signal.The main strategy of this forecasting model is to obtain parameters as the basis for optimizing the radial basis function neural network and to forecast the reconstructed Earth’s natural pulse electromagnetic field data.In verification experiments,we employ the 3 and 6 days’data of two channels as training samples to forecast the 14 and 21-day Earth’s natural pulse electromagnetic field data respectively.According to the forecasting results and absolute error results,the chaotic radial basis function forecasting model can fit the fluctuation trend of the actual signal strength,effectively reduce the forecasting error compared with the traditional radial basis function model.Hence,this network may be useful for studying the characteristics of the Earth’s natural pulse electromagnetic field signal before a strong earthquake and we hope it can contribute to the electromagnetic anomaly monitoring before the earthquake. 展开更多
关键词 Earth’s natural pulse electromagnetic field Chaos theory Radial Basis Function neural network forecasting model
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Forecasting Alzheimer’s Disease Using Combination Model Based on Machine Learning
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作者 He Li Yuhang Wu +2 位作者 Yingnan Zhang Tao Wei Yufeng Gui 《Applied Mathematics》 2018年第4期403-417,共15页
As the acceleration of aged population tendency, building models to forecast Alzheimer’s Disease (AD) is essential. In this article, we surveyed 1157 interviewees. By analyzing the results using three machine learnin... As the acceleration of aged population tendency, building models to forecast Alzheimer’s Disease (AD) is essential. In this article, we surveyed 1157 interviewees. By analyzing the results using three machine learning methods—BP neural network, SVM and random forest, we can derive the accuracy of them in forecasting AD, so that we can compare the methods in solving AD prediction. Among them, random forest is the most accurate method. Moreover, to combine the advantages of the methods, we build a new combination forecasting model based on the three machine learning models, which is proved more accurate than the models singly. At last, we give the conclusion of the connection between life style and AD, and provide several suggestions for elderly people to help them prevent AD. 展开更多
关键词 Alzheimer’s Disease BP NEURAL Network sVM RANDOM FOREsT Combination forecasting Model
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A Hybrid Particle Swarm Optimization to Forecast Implied Volatility Risk
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作者 Kais Tissaoui Sahbi Boubaker +2 位作者 Waleed Saud Alghassab Taha Zaghdoudi Jamel Azibi 《Computers, Materials & Continua》 SCIE EI 2022年第11期4291-4309,共19页
The application of optimization methods to prediction issues is a continually exploring field.In line with this,this paper investigates the connectedness between the infected cases of COVID-19 and US fear index from a... The application of optimization methods to prediction issues is a continually exploring field.In line with this,this paper investigates the connectedness between the infected cases of COVID-19 and US fear index from a forecasting perspective.The complex characteristics of implied volatility risk index such as non-linearity structure,time-varying and nonstationarity motivate us to apply a nonlinear polynomial Hammerstein model with known structure and unknown parameters.We use the Hybrid Particle Swarm Optimization(HPSO)tool to identify the model parameters of nonlinear polynomial Hammerstein model.Findings indicate that,following a nonlinear polynomial behaviour cascaded to an autoregressive with exogenous input(ARX)behaviour,the fear index in US financial market is significantly affected by COVID-19-infected cases in the US,COVID-19-infected cases in the world and COVID-19-infected cases in China,respectively.Statistical performance indicators provided by the developed models show that COVID-19-infected cases in the US are particularly powerful in predicting the Cboe volatility index compared to COVID-19-infected cases in the world and China(MAPE(2.1013%);R2(91.78%)and RMSE(0.6363 percentage points)).The proposed approaches have also shown good convergence characteristics and accurate fits of the data. 展开更多
关键词 forecasting Cboe’s volatility index COVID-19 pandemic nonlinear polynomial hammerstein model hybrid particle swarm optimization
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基于BiLSTM-Attention的F_(10.7)指数预测模型与中国自主数据集的应用
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作者 闫帅楠 李雪宝 +7 位作者 董亮 黄文耿 王晶 闫鹏朝 娄恒瑞 黄徐胜 李哲 郑艳芳 《空间科学学报》 CAS CSCD 北大核心 2024年第2期251-261,共11页
F_(10.7)指数是太阳活动的重要指标,准确预测F_(10.7)指数有助于预防和缓解太阳活动对无线电通信、导航和卫星通信等领域的影响.基于F_(10.7)射电流量的特性,在双向长短时记忆网络(Bidirectional Long Short-Term Memory Network,BiLSTM... F_(10.7)指数是太阳活动的重要指标,准确预测F_(10.7)指数有助于预防和缓解太阳活动对无线电通信、导航和卫星通信等领域的影响.基于F_(10.7)射电流量的特性,在双向长短时记忆网络(Bidirectional Long Short-Term Memory Network,BiLSTM)基础上融入注意力机制(Attention),提出了一种基于BiLSTM-Attention的F_(10.7)预报模型.在加拿大DRAO数据集上其平均绝对误差(MAE)为5.38,平均绝对百分比误差(MAPE)控制在5%以内,相关系数(R)高达0.987,与其他RNN模型相比拥有优越的预测性能.针对中国廊坊L&S望远镜观测的F_(10.7)数据集,提出了一种转换平均校准(Conversion Average Calibration,CAC)方法进行数据预处理,处理后的数据与DRAO数据集具有较高的相关性.基于该数据集对比分析了RNN系列模型的预报效果,实验结果表明,BiLSTM-Attention和BiLSTM两种模型在预测F_(10.7)指数方面具有较好的优势,表现出较好的预测性能和稳定性. 展开更多
关键词 F_(10.7)预报 双向长短时记忆网络 注意力机制 L&s数据集
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ESG改善对企业劳动投资效率的提升作用研究 被引量:1
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作者 杨洁 丁洁 《西部论坛》 CSSCI 北大核心 2024年第2期69-84,共16页
企业ESG表现的改善,能够强化内部控制,优化信息环境,进而可以通过缓解委托代理冲突和加强外部监督来提高劳动投资决策的科学性和有效性,实现劳动投资效率的提升。采用沪深A股上市公司2009—2022年的数据分析发现:ESG表现改善可以显著提... 企业ESG表现的改善,能够强化内部控制,优化信息环境,进而可以通过缓解委托代理冲突和加强外部监督来提高劳动投资决策的科学性和有效性,实现劳动投资效率的提升。采用沪深A股上市公司2009—2022年的数据分析发现:ESG表现改善可以显著提升企业的劳动投资效率,该结论在经过缓解内生性、变量处理、排除非劳动投资影响等一系列稳健性检验后依然成立;ESG表现改善主要通过优化企业的雇佣行为来提升劳动投资效率,即以减少雇佣(而非增加解雇)的方式抑制劳动投资过度,以增加雇佣(而非减少解雇)的方式缓解劳动投资不足;ESG表现改善能够通过降低代理成本和提高分析师预测质量两条路径来提高企业劳动投资效率,并对信息披露质量较高的企业和劳动密集度较高的企业具有更为显著的劳动投资效率提升效应。因此,企业应积极增加ESG投资,并通过提高自身的信息披露质量促进分析师预测质量提升,通过降低代理成本减少非效率劳动投资行为,以有效提升劳动投资效率。 展开更多
关键词 EsG表现 劳动投资效率 代理成本 分析师预测 过度雇佣 雇佣不足
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Forecasting the New Trends about the Consumer Behavior in the Cruise Industry Post COVID-19
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作者 Ana Lucia Rodrigues da Silva Reinaldo Castro Souza 《Journal of Data Analysis and Information Processing》 2022年第1期58-77,共20页
This paper presented the new sanitary and health protocols implemented by cruise companies in order to internationally resuming the industry. The perception of Brazilians regarding these new protocols was identified t... This paper presented the new sanitary and health protocols implemented by cruise companies in order to internationally resuming the industry. The perception of Brazilians regarding these new protocols was identified through a quantitative survey with a sample of 412 Brazilian respondents, carried out between May and June 2021. As main results, sanitary and health protocols that do not affect their experiences on board were identified, as well as those protocols that compromised the experience perceived by the future traveler. The respondents’ propensity to travel on cruise ships and their perceptions about the influence of the ship size, the number of ports of call, nationalities on board, the number of guests, among other aspects, were also analyzed. Finally, in the final section of this paper, we presented an estimation of the expected number of cruisers for the 21/22 cruising season in Brazil, based on a kind Bayesian argument, considering different scenarios for the forthcoming season. 展开更多
关键词 Cruise Industry COVID-19 sanitary and Health Protocols Quantitative sur-vey forecasting Brazilian’s Cruisers
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