宁夏近50年来气候变化特征及其变化趋势

依据宁夏1951—2008年降水及气温资料,运用滑动平均、气候趋势系数分析等方法分析了宁夏近半个多世纪气候的时空变化规律及其变化趋势。结果表明：宁夏年降水量由北向南依次递增,多年平均温度南部山区低于引黄灌区,中部干旱带最高。降水、气温变异系数均较小,极端事件较少。1990年和2000年是气温的突变点。中部干旱带及南部山区降水呈减少趋势的概率均为75％,引黄灌区迭71．4％．全区降水减少的概率达到733％。全区气温整体呈现升高趋势,其中南部山区气温升高的概率均迭100％,引黄灌区85．7％,全区为86．7％。宁夏有趋于暖干的可能。     

汽车故障诊断技术的现状与发展趋势

汽车诊断技术在过去的几十年中取得了迅速的发展,本文介绍了汽车故障诊断技术的发展历程,阐述了汽车故障诊断技术的发展现状,并展望了汽车故障诊断技术的发展趋势。     

A comparative evaluation of objective and subjective weather forecasts in the united states

This paper is concerned primarily with the evaluation and comparison of objective and subjective weather forecasts. Operational forecasts of three weather elements are considered: (1) probability forecasts of precipitation occurrence, (2) categorical (i.e. non-probabilistic) forecasts of maximum and minimum temperatures and (3) categorical forecasts of cloud amount. The objective forecasts are prepared by numerical-statistical procedures, whereas the subjective forecasts are based on the judgements of individual forecasters. In formulating the latter, the forecasters consult information from a variety of sources, including the objective forecasts themselves. The precipitation probability forecasts are found to be both reliable and skilful, and evaluation of the temperature/cloud amount forecasts reveals that they are quite accurate/skilful. Comparison of the objective and subjective forecasts of precipitation occurrence indicates that the latter are generally more skilful than the former for shorter lead times (e.g. 12–24 hours), whereas the two types of forecasts are of approximately equal skill for longer lead times (e.g. 36–48 hours). Similar results are obtained for the maximum and minimum temperature forecasts. Objective cloud amount forecasts are more skilful than subjective cloud amount forecasts for all lead times. Examination of trends in performance over the last decade reveals that both types of forecasts for all three elements increased in skill (or accuracy) over the period, with improvements in objective forecasts equalling or exceeding improvements in subjective forecasts. The role and impact of the objective forecasts in the subjective weather forecasting process are discussed in some detail. The need to conduct controlled experiments and other studies of this process, with particular reference to the assimilation of information from different sources, is emphasized. Important characteristics of the forecasting system in meteorology are identified, and they are used to describe similarities and differences between weather forecasting and forecasting in other fields. Acquisition of some of these characteristics may be beneficial to other forecasting systems.     

后金融危机时期中国艺术品市场的发展

从2008年9月开始的这场金融风暴已波及到实体经济,不仅股市下跌,几乎所有具备投资属性的商品价格都受到打压,艺术品的价格也在跌,金融市场的这场风暴对艺术市场造成的影响已经显而易见。本文对于金融危机下的中国艺术市场现状作了初步分析,进而分析金融风暴对艺术市场未来走向的影响及应对策略。     

Filtering and prediction of noisy and unstable signals: The case of Google Trends data

Google Trends data is a dataset increasingly employed for many statistical investigations. However, care should be placed in handling this tool, especially when applied for quantitative prediction purposes. Being by design Internet user dependent, estimators based on Google Trends data embody many sources of uncertainty and instability. They are related, for example, to technical (e.g., cross-regional disparities in the degree of computer alphabetization, time dependency of Internet users), psychological (e.g., emotionally driven spikes and other form of data perturbations), linguistic (e.g., noise generated by double-meaning words). Despite the stimulating literature available today on how to use Google Trends data as a forecasting tool, surprisingly, to the best of the author's knowledge, it appears that to date no articles specifically devoted to the prediction of these data have been published. In this paper, a novel forecasting method, based on a denoiser of the wavelet type employed in conjunction with a forecasting model of the class SARIMA (seasonal autoregressive integrated moving average), is presented. The wavelet filter is iteratively calibrated according to a bounded search algorithm, until a minimum of a suitable loss function is reached. Finally, empirical evidence is presented to support the validity of the proposed method.     

大数据环境下机器学习算法趋势研究

对大数据环境下的机器学习算法进行阐述,通过研究其重点内涵,探究其未来发展的趋势,并且对其中一些关键性的技术进行重点分析,以期对这方面的研究有一定的帮助.     

论21世纪高校图书馆读者服务工作的发展趋势

从读者服务理念、服务内容与服务手段等方面探讨了21世纪图书馆读者服务工作的发展趋势,指出21世纪高校图书馆读者服务的重点将是个性化的信息咨询服务,并呈现多元化的服务模式。     

Forecasting private consumption with Google Trends data

This paper examines the predictive relationship of consumption‐related and news‐related Google Trends data to changes in private consumption in the USA. The results suggest that (1) Google Trends‐augmented models provide additional information about consumption over and above survey‐based consumer sentiment indicators, (2) consumption‐related Google Trends data provide information about pre‐consumption research trends, (3) news‐related Google Trends data provide information about changes in durable goods consumption, and (4) the combination of news and consumption‐related data significantly improves forecasting models. We demonstrate that applying these insights improves forecasts of private consumption growth over forecasts that do not utilize Google Trends data and over forecasts that use Google Trends data, but do not take into account the specific ways in which it informs forecasts.     

中国重点骨干烟草品牌市场变化趋势

针对我国重点骨干烟草品牌市场趋势呈现的稳步、均衡、可持续特点,以及销量增长逐年递增、增幅递减的态势,选择ARIMA模型对重点骨干烟草品牌市场趋势进行预测,取得了精度较高的结果,为烟草企业生产经营提供决策依据。     

生物工程专业人才需求趋势和特征分析

以浙江中医医药大学生物工程专业本科毕业生就业去向及岗位群分析为基础,通过座谈、网络和问卷等方式,调研了社会对生物工程专业人才需求趋势,企业对该类人才的岗位需求与能力需求情况,为进一步完善医学类生物工程专业人才培养和实施教学改革提供依据。