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
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
Business English reading teaching under the mode of“literature circles”focuses on cultivating students’autonomy in reading,group cooperation,and the exchange of ideas among group members.In this teaching mode,teach...Business English reading teaching under the mode of“literature circles”focuses on cultivating students’autonomy in reading,group cooperation,and the exchange of ideas among group members.In this teaching mode,teachers are no longer the masters of the reading classroom,but the helpers,participants,and researchers in the process of students’reading.The reconstruction of teachers’role can promote the benign development of relationship not only between teachers and students,but also between students and students,inject new impetus and vitality into the classroom,and improve students’reading literacy.展开更多
English speaking has been paid more attention today, especially in the age of globalization. Teachers are attempting to find out more effective methods to enhance the teaching results of English speaking. Facing the g...English speaking has been paid more attention today, especially in the age of globalization. Teachers are attempting to find out more effective methods to enhance the teaching results of English speaking. Facing the great demands and present difficulties of oral English classes, teachers have to conduct more study and practice to find out what roles that an oral English teacher has to take in the oral English classroom. Compared with the traditional teaching role in the English classroom, an oral English teacher has to fulfill more than one role in the classroom teaching so as to provide better learning conditions for students. Lacking more exposure to the real interaction with native speakers, students expect the oral English teacher to be a creator of the language environment. With various teaching and learning activities in the oral English classroom, the teacher has to be a good organizer to ensure every student to achieve improvement. An oral English teacher also has to correct students'language errors while ensuring the smooth progress of the classroom teaching. Only when an oral English teacher make clear what roles he or she has to take in the classroom can he or she achieve effective teaching.展开更多
It is commonly known that writing is an advanced skill which is essential in language learning but at the same time the most difficult task for learners. This paper is with the aim to explore helpful roles that teache...It is commonly known that writing is an advanced skill which is essential in language learning but at the same time the most difficult task for learners. This paper is with the aim to explore helpful roles that teacher can play to help non-English major students improve their English writing, so as to help improve their writing ability in the author's context.展开更多
The main advantages of role-based access control (RBAC) are able to support the well-known security principles and roles'inheritance. But for there remains a lack of specific definition and the necessary formalizat...The main advantages of role-based access control (RBAC) are able to support the well-known security principles and roles'inheritance. But for there remains a lack of specific definition and the necessary formalization for RBAC, it is hard to realize RBAC in practical work. Our contribution here is to formalize the main relations of RBAC and take first step to propose concepts of action closure and deta closure of a role, based on which we got the specification and algorithm for the least privileges of a role. We propose that roles' inheritance should consist of inheritance of actions and inheritance of data, and then we got the inheritance of privileges among roles, which can also be supported by existing exploit tools.展开更多
The doping of phosphorus, sulfur and boron in IN718 superalloy can remarkably influence the creep behavior. The modifications of the minor elements seem not to vary the stress exponent and the influences primarily con...The doping of phosphorus, sulfur and boron in IN718 superalloy can remarkably influence the creep behavior. The modifications of the minor elements seem not to vary the stress exponent and the influences primarily concentrate on the effective diffusion coefficient. A pronounced beneficial interaction between P and B and a weaker detrimental interaction between P and S have been obtained. The preexponential frequency constant is proved to be strongly related with the creep activation energy because of the so-called compensation effect. The compensation temperature has been determined to be about 1080 K, which corresponds to the transformation temperature from rapidly coarsened γ'' phase to δ phase. It has been proposed that trace elements can influence the effective diffusion coefficient individually or cooperatively, which in turn either retard or speed the creep process.展开更多
Alzheimer's disease(AD)is a fatal progressive neurodegenerative disorder characterized by loss in memory,cognition,and executive function and activities of daily living.AD pathogenesis has been shown to involve los...Alzheimer's disease(AD)is a fatal progressive neurodegenerative disorder characterized by loss in memory,cognition,and executive function and activities of daily living.AD pathogenesis has been shown to involve loss of neurons and synapses,cholinergic deficits,amyloid-beta protein(Aβ)deposition,tau protein hyperphosphorylation, and neuroinflammation.展开更多
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
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
Autosomal recessive mutations in the PARK7 gene,which encodes for the protein DJ-1,result in a loss of function and are a cause of familial Parkinson’s disease(PD),while increased wild-type DJ-1protein levels are a...Autosomal recessive mutations in the PARK7 gene,which encodes for the protein DJ-1,result in a loss of function and are a cause of familial Parkinson’s disease(PD),while increased wild-type DJ-1protein levels are associated with some forms of cancer.Several functions of DJ-1 have been described,with the greatest evidence indicating that DJ-1 is a redox-sensitive protein involved in the regulation of oxidative stress and cell survival.展开更多
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
In the history of feudal society,women were suffering from the oppression and inequality in their family and status,and also strict restriction from the society.Their freedom was limited and they could not make full u...In the history of feudal society,women were suffering from the oppression and inequality in their family and status,and also strict restriction from the society.Their freedom was limited and they could not make full use of their wisdom,and abili ty.But the role of women did not stay the same during the feudal society.It had changed though the fundamental role remained the same.Here in this essay,it mainly talked about the changing role of Chinese in history,from the beginning of the Qing Dy nasty to the end of the Qing Dynasty.It collected information,and evidences from two books which were of great value to inves tigate women's role.They were Cao Xueqin's the Dream of Red Mansions and Lin Yutang's Moment in Peking.A great por tion of these two book's main characters were women,no matter what their social statuses were,no matter what roles they were playing in the big feudal family.Based on the result of analysis,the study suggests that women have been making progress all the time in changing their situation.And the development of economy has given women immense chances to achieve their self-actu alization.展开更多
This paper first reviewed a controversial case in which a teacher ran away from his students in a earthquake. Several educational ethnic questions were aroused from the case: Is protecting students part of teacher'...This paper first reviewed a controversial case in which a teacher ran away from his students in a earthquake. Several educational ethnic questions were aroused from the case: Is protecting students part of teacher's job? To what extent should it be applied? etc. Then the author aims to answer these questions based on a real case study from philosophical perspective, that is, analyzing teacher's role(i) as a human being;(ii) as a educator;(iii) as a educatee. Finally the paper concludes that teachers should protect their students even under life threatening circumstances.展开更多
Among the sundry studies in China on John Donne's The Flea,there has been none done from the perspective of Reader-Oriented Theory to probe into the readers' roles in the construction of meaning.The present ar...Among the sundry studies in China on John Donne's The Flea,there has been none done from the perspective of Reader-Oriented Theory to probe into the readers' roles in the construction of meaning.The present article under Wolfgang Iser's theories,in a further pursuit of the expansion of the gestalt of such studies on the poem,aims at exploring the readers' active roles in complementing,completing and recreating the textual meaning,and differentiating the implied reader and the actual reader through the poem as well as attempting to fulfill the construction of the reading cognitive model through the interpretation of the conceit the flea.展开更多
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
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
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
Along with the progress in breadth and depth of international arms controland disarmament, US-led Western nations are increasingly in need of China’s co-operation. They began to seek consultations and coordination wi...Along with the progress in breadth and depth of international arms controland disarmament, US-led Western nations are increasingly in need of China’s co-operation. They began to seek consultations and coordination with China. This hasled to China’ s bigger say and rising role in international arms control.展开更多
基金supported by the National Natural Science Foundation of China (Grant Nos. 42025404, 42188101, and 42241143)the National Key R&D Program of China (Grant Nos. 2022YFF0503700 and 2022YFF0503900)+1 种基金the B-type Strategic Priority Program of the Chinese Academy of Sciences (Grant No. XDB41000000)the Fundamental Research Funds for the Central Universities (Grant No. 2042022kf1012)
文摘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.
文摘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.
基金“Research on Reading Teaching Mode of Business English Majors From the Perspective of Literature Circles”(Project No.:2021SCG112)Laboratory Opening Project in Quzhou University(Project No.KFXM201808).
文摘Business English reading teaching under the mode of“literature circles”focuses on cultivating students’autonomy in reading,group cooperation,and the exchange of ideas among group members.In this teaching mode,teachers are no longer the masters of the reading classroom,but the helpers,participants,and researchers in the process of students’reading.The reconstruction of teachers’role can promote the benign development of relationship not only between teachers and students,but also between students and students,inject new impetus and vitality into the classroom,and improve students’reading literacy.
文摘English speaking has been paid more attention today, especially in the age of globalization. Teachers are attempting to find out more effective methods to enhance the teaching results of English speaking. Facing the great demands and present difficulties of oral English classes, teachers have to conduct more study and practice to find out what roles that an oral English teacher has to take in the oral English classroom. Compared with the traditional teaching role in the English classroom, an oral English teacher has to fulfill more than one role in the classroom teaching so as to provide better learning conditions for students. Lacking more exposure to the real interaction with native speakers, students expect the oral English teacher to be a creator of the language environment. With various teaching and learning activities in the oral English classroom, the teacher has to be a good organizer to ensure every student to achieve improvement. An oral English teacher also has to correct students'language errors while ensuring the smooth progress of the classroom teaching. Only when an oral English teacher make clear what roles he or she has to take in the classroom can he or she achieve effective teaching.
文摘It is commonly known that writing is an advanced skill which is essential in language learning but at the same time the most difficult task for learners. This paper is with the aim to explore helpful roles that teacher can play to help non-English major students improve their English writing, so as to help improve their writing ability in the author's context.
基金Supported by the National Natural Science Foun-dation of China (60403027)
文摘The main advantages of role-based access control (RBAC) are able to support the well-known security principles and roles'inheritance. But for there remains a lack of specific definition and the necessary formalization for RBAC, it is hard to realize RBAC in practical work. Our contribution here is to formalize the main relations of RBAC and take first step to propose concepts of action closure and deta closure of a role, based on which we got the specification and algorithm for the least privileges of a role. We propose that roles' inheritance should consist of inheritance of actions and inheritance of data, and then we got the inheritance of privileges among roles, which can also be supported by existing exploit tools.
基金supported by the National Natural Science Foundation of China No.59801013 and No.59771056
文摘The doping of phosphorus, sulfur and boron in IN718 superalloy can remarkably influence the creep behavior. The modifications of the minor elements seem not to vary the stress exponent and the influences primarily concentrate on the effective diffusion coefficient. A pronounced beneficial interaction between P and B and a weaker detrimental interaction between P and S have been obtained. The preexponential frequency constant is proved to be strongly related with the creep activation energy because of the so-called compensation effect. The compensation temperature has been determined to be about 1080 K, which corresponds to the transformation temperature from rapidly coarsened γ'' phase to δ phase. It has been proposed that trace elements can influence the effective diffusion coefficient individually or cooperatively, which in turn either retard or speed the creep process.
文摘Alzheimer's disease(AD)is a fatal progressive neurodegenerative disorder characterized by loss in memory,cognition,and executive function and activities of daily living.AD pathogenesis has been shown to involve loss of neurons and synapses,cholinergic deficits,amyloid-beta protein(Aβ)deposition,tau protein hyperphosphorylation, and neuroinflammation.
基金China-Korea Cooperation Project on the development of oceanic monitoring and prediction system on nuclear safetythe Project of the National Programme on Global Change and Air-sea Interaction under contract No.GASI-03-IPOVAI-05
文摘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.
基金Project 40472146 supported by the National Natural Science Foundation of China
文摘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.
基金funded by a Medical Research Council(UK)Experimental Medicine grant[MR/M006646/1]
文摘Autosomal recessive mutations in the PARK7 gene,which encodes for the protein DJ-1,result in a loss of function and are a cause of familial Parkinson’s disease(PD),while increased wild-type DJ-1protein levels are associated with some forms of cancer.Several functions of DJ-1 have been described,with the greatest evidence indicating that DJ-1 is a redox-sensitive protein involved in the regulation of oxidative stress and cell survival.
文摘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.
文摘In the history of feudal society,women were suffering from the oppression and inequality in their family and status,and also strict restriction from the society.Their freedom was limited and they could not make full use of their wisdom,and abili ty.But the role of women did not stay the same during the feudal society.It had changed though the fundamental role remained the same.Here in this essay,it mainly talked about the changing role of Chinese in history,from the beginning of the Qing Dy nasty to the end of the Qing Dynasty.It collected information,and evidences from two books which were of great value to inves tigate women's role.They were Cao Xueqin's the Dream of Red Mansions and Lin Yutang's Moment in Peking.A great por tion of these two book's main characters were women,no matter what their social statuses were,no matter what roles they were playing in the big feudal family.Based on the result of analysis,the study suggests that women have been making progress all the time in changing their situation.And the development of economy has given women immense chances to achieve their self-actu alization.
文摘This paper first reviewed a controversial case in which a teacher ran away from his students in a earthquake. Several educational ethnic questions were aroused from the case: Is protecting students part of teacher's job? To what extent should it be applied? etc. Then the author aims to answer these questions based on a real case study from philosophical perspective, that is, analyzing teacher's role(i) as a human being;(ii) as a educator;(iii) as a educatee. Finally the paper concludes that teachers should protect their students even under life threatening circumstances.
文摘Among the sundry studies in China on John Donne's The Flea,there has been none done from the perspective of Reader-Oriented Theory to probe into the readers' roles in the construction of meaning.The present article under Wolfgang Iser's theories,in a further pursuit of the expansion of the gestalt of such studies on the poem,aims at exploring the readers' active roles in complementing,completing and recreating the textual meaning,and differentiating the implied reader and the actual reader through the poem as well as attempting to fulfill the construction of the reading cognitive model through the interpretation of the conceit the flea.
基金supported by Universidad Nacional de Córdoba(UNC),FONCYT-PDFT PRH No.3(UNC Program RRHH03),SECYT UNC,Universidad Nacional de San Juan—Institute of Automatics(INAUT),National Agency for Scientific and Technological Promotion(ANPCyT)and Departments of Electronics—Electrical and Electronic Engineering—Universidad Nacional of Cordoba.
文摘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.
文摘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.
文摘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.
文摘Along with the progress in breadth and depth of international arms controland disarmament, US-led Western nations are increasingly in need of China’s co-operation. They began to seek consultations and coordination with China. This hasled to China’ s bigger say and rising role in international arms control.