A developing trophic mismatch between the peak of energy demands by reproducing animals and the peak of forage availability has caused many species'reproductive success to decrease.The match-mismatch hypothesis(MM...A developing trophic mismatch between the peak of energy demands by reproducing animals and the peak of forage availability has caused many species'reproductive success to decrease.The match-mismatch hypothesis(MMH)is an appealing concept that can be used to assess such fitness consequences.However,concerns have been raised on applying the MMH on capital breeders such as reindeer because the reliance on maternal capita rather than dietary income may mitigate negative effects of changing phenologies.Using a long-term dataset of reindeer calving dates recorded since 1970 in a semidomesticated reindeer population in Finnish Lapland and proxies of plant phenology;we tested the main hypothesis that the time lag between calving date and the plant phenology in autumn when females store nutrient reserves to finance reproduction would lead to consequences on reproductive success,as the time lag with spring conditions would.As predicted,the reproductive success of females of the Kutuharju reindeer population was affected by both the onset of spring green-up and vegetative senescence in autumn as calves were born heavier and with a higher first-summer survival when the onset of the vegetation growth was earlier and the end of the thermal growing season the previous year was earlier as well.Our results demonstrated that longer plant growing seasons might be detrimental to reindeer's reproductive success if a later end is accompanied by a reduced abundance of mushrooms.展开更多
In this article, a nonlinear dynamic multiway partial least squares (MPLS) based on support vector machines (SVM) is developed for on-line fault detection in batch processes. The approach, referred to as SVM-based DMP...In this article, a nonlinear dynamic multiway partial least squares (MPLS) based on support vector machines (SVM) is developed for on-line fault detection in batch processes. The approach, referred to as SVM-based DMPLS, integrates the SVM with the MPLS model. Process data from normal historical batches are used to develop the MPLS model, and a series of single-input-single-output SVM networks are adopted to approximate nonlinear inner relationship between input and output variables. In addition, the application of a time-lagged window technique not only makes the complementarities of unmeasured data of the monitored batch unnecessary, but also significantly reduces the computation and storage requirements in comparison with the traditional MPLS. The proposed approach is validated by a simulation study of on-line fault detection for a fed-batch penicillin production.展开更多
A time-lagged ensemble method is used to improve 6-15 day precipitation forecasts from the Beijing Climate Center Atmospheric General Circulation Model,version 2.0.1.The approach averages the deterministic predictions...A time-lagged ensemble method is used to improve 6-15 day precipitation forecasts from the Beijing Climate Center Atmospheric General Circulation Model,version 2.0.1.The approach averages the deterministic predictions of precipitation from the most recent model run and from earlier runs,all at the same forecast valid time.This lagged average forecast （LAF） method assigns equal weight to each ensemble member and produces a forecast by taking the ensemble mean.Our analyses of the Equitable Threat Score,the Hanssen and Kuipers Score,and the frequency bias indicate that the LAF using five members at time-lagged intervals of 6 h improves 6-15 day forecasts of precipitation frequency above 1 mm d-1 and 5 mm d-1 in many regions of China,and is more effective than the LAF method with selection of the time-lagged interval of 12 or 24 h between ensemble members.In particular,significant improvements are seen over regions where the frequencies of rainfall days are higher than about 40％-50％ in the summer season; these regions include northeastern and central to southern China,and the southeastem Tibetan Plateau.展开更多
Information Technology （IT） investments, especially Enterprise Resource Planning （ERP） systems, are critical for the survival and development of companies. Therefore, understanding the impact of ERP in- vestment i...Information Technology （IT） investments, especially Enterprise Resource Planning （ERP） systems, are critical for the survival and development of companies. Therefore, understanding the impact of ERP in- vestment is of great importance to managers and researchers. As a corporate performance indicator, Tobin＇s Q has some inherent advantages compared to other accounting indicators, and it can better reflect the con- tribution of ERP investment to company performance. This study employs multiple regression models to examine the impact of ERP investment on Tobin＇s Q. The sample consists of 126 manufacturing companies listed on the Shanghai and Shenzhen Stock Exchanges from 1999 to 2007. Empirical results show that in the first three years after ERP implementation, there is no significant change in Tobin＇s Q; however, in the fourth year, Tobin＇s Q increases significantly. The results indicate that, as a strategic long-term investment accompanied by large-scale business process reengineering and organizational learning, ERP implementa- tion has time-lagged effects; nonetheless, it eventually produces significant benefits.展开更多
In this article, a nonlinear dynamic multiway partial least squares (MPLS) based on support vector ma- chines (SVM) is developed for on-line fault detection in batch processes. The approach, referred to as SVM-based D...In this article, a nonlinear dynamic multiway partial least squares (MPLS) based on support vector ma- chines (SVM) is developed for on-line fault detection in batch processes. The approach, referred to as SVM-based DMPLS, integrates the SVM with the MPLS model. Process data from normal historical batches are used to de- velop the MPLS model, and a series of single-input-single-output SVM networks are adopted to approximate nonlinear inner relationship between input and output variables. In addition, the application of a time-lagged win- dow technique not only makes the complementarities of unmeasured data of the monitored batch unnecessary, but also significantly reduces the computation and storage requirements in comparison with the traditional MPLS. The proposed approach is validated by a simulation study of on-line fault detection for a fed-batch penicillin production.展开更多
基金This work was supported by funding from the Natural Sciences and Engineering Research Council of Canada(NSERC)to R.B.WThe contributions of J.K.and O.H.were funded by Reindeer Husbandry in a Globalizing North(ReiGN),which is a Nordforsk-funded"Nordic Centre of Excellence"(project number 76915).
文摘A developing trophic mismatch between the peak of energy demands by reproducing animals and the peak of forage availability has caused many species'reproductive success to decrease.The match-mismatch hypothesis(MMH)is an appealing concept that can be used to assess such fitness consequences.However,concerns have been raised on applying the MMH on capital breeders such as reindeer because the reliance on maternal capita rather than dietary income may mitigate negative effects of changing phenologies.Using a long-term dataset of reindeer calving dates recorded since 1970 in a semidomesticated reindeer population in Finnish Lapland and proxies of plant phenology;we tested the main hypothesis that the time lag between calving date and the plant phenology in autumn when females store nutrient reserves to finance reproduction would lead to consequences on reproductive success,as the time lag with spring conditions would.As predicted,the reproductive success of females of the Kutuharju reindeer population was affected by both the onset of spring green-up and vegetative senescence in autumn as calves were born heavier and with a higher first-summer survival when the onset of the vegetation growth was earlier and the end of the thermal growing season the previous year was earlier as well.Our results demonstrated that longer plant growing seasons might be detrimental to reindeer's reproductive success if a later end is accompanied by a reduced abundance of mushrooms.
基金Supported by the National Natural Science Foundation of China (No.60574038) and the Open Project Program of the State Key Laboratory of Bioreactor Engineering/ECUST.
文摘In this article, a nonlinear dynamic multiway partial least squares (MPLS) based on support vector machines (SVM) is developed for on-line fault detection in batch processes. The approach, referred to as SVM-based DMPLS, integrates the SVM with the MPLS model. Process data from normal historical batches are used to develop the MPLS model, and a series of single-input-single-output SVM networks are adopted to approximate nonlinear inner relationship between input and output variables. In addition, the application of a time-lagged window technique not only makes the complementarities of unmeasured data of the monitored batch unnecessary, but also significantly reduces the computation and storage requirements in comparison with the traditional MPLS. The proposed approach is validated by a simulation study of on-line fault detection for a fed-batch penicillin production.
基金supported by the National Basic Research Program of China (973 Program: Grant No. 2010CB951902)the Special Program for China Meteorology Trade (Grant No. GYHY201306020)the Technology Support Program of China (Grant No. 2009BAC51B03)
文摘A time-lagged ensemble method is used to improve 6-15 day precipitation forecasts from the Beijing Climate Center Atmospheric General Circulation Model,version 2.0.1.The approach averages the deterministic predictions of precipitation from the most recent model run and from earlier runs,all at the same forecast valid time.This lagged average forecast （LAF） method assigns equal weight to each ensemble member and produces a forecast by taking the ensemble mean.Our analyses of the Equitable Threat Score,the Hanssen and Kuipers Score,and the frequency bias indicate that the LAF using five members at time-lagged intervals of 6 h improves 6-15 day forecasts of precipitation frequency above 1 mm d-1 and 5 mm d-1 in many regions of China,and is more effective than the LAF method with selection of the time-lagged interval of 12 or 24 h between ensemble members.In particular,significant improvements are seen over regions where the frequencies of rainfall days are higher than about 40％-50％ in the summer season; these regions include northeastern and central to southern China,and the southeastem Tibetan Plateau.
基金Supported by the National Natural Science Foundation of China (No. 70831003)
文摘Information Technology （IT） investments, especially Enterprise Resource Planning （ERP） systems, are critical for the survival and development of companies. Therefore, understanding the impact of ERP in- vestment is of great importance to managers and researchers. As a corporate performance indicator, Tobin＇s Q has some inherent advantages compared to other accounting indicators, and it can better reflect the con- tribution of ERP investment to company performance. This study employs multiple regression models to examine the impact of ERP investment on Tobin＇s Q. The sample consists of 126 manufacturing companies listed on the Shanghai and Shenzhen Stock Exchanges from 1999 to 2007. Empirical results show that in the first three years after ERP implementation, there is no significant change in Tobin＇s Q; however, in the fourth year, Tobin＇s Q increases significantly. The results indicate that, as a strategic long-term investment accompanied by large-scale business process reengineering and organizational learning, ERP implementa- tion has time-lagged effects; nonetheless, it eventually produces significant benefits.
基金the National Natural Science Foundation of China (No.60574038) the Open Project Program of the State KeyLaboratory of Bioreactor Engineering/ECUST.
文摘In this article, a nonlinear dynamic multiway partial least squares (MPLS) based on support vector ma- chines (SVM) is developed for on-line fault detection in batch processes. The approach, referred to as SVM-based DMPLS, integrates the SVM with the MPLS model. Process data from normal historical batches are used to de- velop the MPLS model, and a series of single-input-single-output SVM networks are adopted to approximate nonlinear inner relationship between input and output variables. In addition, the application of a time-lagged win- dow technique not only makes the complementarities of unmeasured data of the monitored batch unnecessary, but also significantly reduces the computation and storage requirements in comparison with the traditional MPLS. The proposed approach is validated by a simulation study of on-line fault detection for a fed-batch penicillin production.
