全面画像而非简单指标

<正>本报告强调:当有关科研人员及其机构的数据被压缩为简单的指标和排名时,有些信息将会遗失。本报告阐述了四类常见分析,如若误用将掩盖真实的科研表现;我们提出了四种可视化选项,用于解读每个度量指标下蕴含的更丰富的信息,以支持开展全面的、负责任的科研管理。我们身边依然存在着声称可通过简单分析来评估论文、科研人员和机构表现的现象。尽管资深分析专家提出反对意见,诸多研究人员对此深表忧虑,但是大学管     

BonJour on explanation and skepticism

Laurence BonJour, among others, has argued that inference to the best explanation allows us to reject skeptical hypotheses in favor of our common-sense view of the world. BonJour considers several skeptical hypotheses, specifically: (i) our experiences arise by mere chance, uncaused; (ii) the simple hypothesis which states merely that our experiences are caused unveridically; and (iii) an elaborated hypothesis which explains in detail how our unveridical experiences are brought about. A central issue is whether the coherence of one’s experience makes that experience more likely to be veridical. BonJour’s recent treatment of “analog” and “digital” skeptical hypotheses is also discussed. I argue that, although there are important lessons to be learned from BonJour’s writings, his use of inference to the best explanation against skepticism is unsuccessful.     

Forecasting US inflation by Bayesian model averaging

Recent empirical work has considered the prediction of inflation by combining the information in a large number of time series. One such method that has been found to give consistently good results consists of simple equal‐weighted averaging of the forecasts from a large number of different models, each of which is a linear regression relating inflation to a single predictor and a lagged dependent variable. In this paper, I consider using Bayesian model averaging for pseudo out‐of‐sample prediction of US inflation, and find that it generally gives more accurate forecasts than simple equal‐weighted averaging. This superior performance is consistent across subsamples and a number of inflation measures. Copyright © 2008 John Wiley & Sons, Ltd.     

An analysis on the predictability of CAPM beta for momentum returns

This paper demonstrates that the forecasted capital asset pricing model (CAPM) beta of momentum portfolios explains a large portion of the return, ranging from 40% to 60% for stock‐level momentum, and from 30% to 50% for industry‐level momentum. Beta forecasts are from a realized beta estimator using daily returns over the prior year. Periods such as 1969–1989 have been found in earlier studies to contain abnormal profits from momentum trading; however, we show that these were spuriously generated by measurement error in systematic risk. These results cast further doubt on the ability of standard momentum trading strategies to generate abnormal profits.     

Discovery of a large population of the rare winter stonefly Isocapnia mogila Ricker in the Mad River, California (Plecoptera, Capniidae)

Isocapnia mogila , a rare winter stonefly, is found in good numbers in Humboldt County, California. In the 50 years since this species was described, very few specimens were recorded from only 4 sites in California and Oregon. Emergence seems to be higher in the fall and early winter than in the late winter and spring.     

气候网络研究新进展

复杂气候网络的方法是识别分析地球气候系统时空斑图的强有力工具,有助于加深潜在物理过程的认识.简要概述当前复杂网络方法在地球气候系统中的应用,对于所取得的成果做一个阶段性小结.就这一热点问题,讨论存在的主要问题,提出一些解决的办法,并且强调复杂网络方法必须和地球物理过程中的气候学问题紧密相连,同时还指出非线性方法在这一问...     

中东

Thomson Reuters 发布的全球系列研究报告表明,以阿拉伯、伊朗、土耳其为主的中东国家的科学研究与西文国家相比落后许多.当然,也有部分中东的科学家或研究机构从事着世界一流的研究工作.事实上,论文数量及引文指标都清晰地表明,近10年中东地区的研究工作有了很大的进步,表现出了鼓舞人心的发展趋势.