Evaluating Probabilistic Forecasts with Bayesian Signal Detection Models

We propose the use of signal detection theory (SDT) to evaluate the performance of both probabilistic forecasting systems and individual forecasters. The main advantage of SDT is that it provides a principled way to distinguish the response from system diagnosticity, which is defined as the ability to distinguish events that occur from those that do not. There are two challenges in applying SDT to probabilistic forecasts. First, the SDT model must handle judged probabilities rather than the conventional binary decisions. Second, the model must be able to operate in the presence of sparse data generated within the context of human forecasting systems. Our approach is to specify a model of how individual forecasts are generated from underlying representations and use Bayesian inference to estimate the underlying latent parameters. Given our estimate of the underlying representations, features of the classic SDT model, such as the receiver operating characteristic (ROC) curve and the area under the ROC curve (AUC), follow immediately. We show how our approach allows ROC curves and AUCs to be applied to individuals within a group of forecasters, estimated as a function of time, and extended to measure differences in forecastability across different domains. Among the advantages of this method is that it depends only on the ordinal properties of the probabilistic forecasts. We conclude with a brief discussion of how this approach might facilitate decision making.     

Displacement and local linguistic practices: R‐lessness in post‐Katrina Greater New Orleans

Variable r‐lessness in New Orleans English is a salient linguistic feature tied to local place‐based identity. In this study, I examine rates of r‐lessness in the wake of Hurricane Katrina, which caused large‐scale displacement in the region. Participants come from the linguistically conservative suburb of Chalmette, where r‐lessness is more robust than in New Orleans proper. Participants’ connections to Chalmette were measured in two ways: (1) post‐Katrina location status, i.e. whether participants returned or relocated after the storm; (2) place orientation, captured via an ethnographically informed, multifaceted measure of stance and exposure to places outside of Chalmette. Analysis revealed that place orientation better predicts rates of r‐lessness than post‐Katrina location. I argue that the marked quality of r‐lessness makes it available for identity‐driven use to express a connection to Chalmette. This study demonstrates one way to account for the linguistic implications of individuals’ shifting allegiances to places they live(d).     

Benchmark Dose Analysis via Nonparametric Regression Modeling

Estimation of benchmark doses (BMDs) in quantitative risk assessment traditionally is based upon parametric dose‐response modeling. It is a well‐known concern, however, that if the chosen parametric model is uncertain and/or misspecified, inaccurate and possibly unsafe low‐dose inferences can result. We describe a nonparametric approach for estimating BMDs with quantal‐response data based on an isotonic regression method, and also study use of corresponding, nonparametric, bootstrap‐based confidence limits for the BMD. We explore the confidence limits’ small‐sample properties via a simulation study, and illustrate the calculations with an example from cancer risk assessment. It is seen that this nonparametric approach can provide a useful alternative for BMD estimation when faced with the problem of parametric model uncertainty.     

我国成品油流通行业市场进入的博弈分析

利用博弈理论分析我国成品油流通市场，发现：适度的、透明的市场进入固定成本对整个市场结构是有利的；要使成品油流通市场更有效率，并保护各方利益，政府应鼓励流通领域竞争，并更大限度地发挥市场配置资源的基础性作用，从而逐渐形成合理有效的市场结构。     

古今偏义复词的对比分析

＂偏义复词＂是一个语言学名词,它具有高度的概括性。古今偏义复词是继承发展的,两者有相同点,但又存在偏指义语素定位、对语境的依赖程度、语素的凝固性、语用等方面的差异,通过对比分析,可提高驾驭语言的能力。     

探讨现代企业财务分析的持续改进的几点建议

分析传统财务分析中存在的主要问题，结合当前的财务分析状况，从企业现金流量情况、资源的效能结构、企业创新能力、企业营销、成本控制等方面提出了一些对策和建议。     

基于趋势面分析的ST类上市公司分布特征研究

上证所与深证所共有1727只股票(含B股)(截止2010年5月7日),其中ST类股票169只.本文运用趋势面分析对ST类股票的分布特征进行了研究.研究结果表明,地理位置与ST类公司的数量之间有显著的相关性,了解其分布特征可以帮助投资者判断某一地理区域投资环境的优劣.     

Production planning and control within a CIM environment: some current developments and requirements for the future

Abstract. This paper considers the integration problems associated with incorporating production planning and control (PP&C) systems within CIM; these problems are typically not differentiated from functionally related problems, and have in the past received relatively little attention. The on-going emergence of a number of standards relevant to manufacturing software systems provides an opportunity to assess the current situation with regard to proprietary PP&C systems and to suggest ways forward towards ‘seamless’ integration of PP&C within the CIM environment. The problems arising from conventional integration approaches are briefly described, and the concept of a simplifying ‘integration platform’ is introduced; the three-schema information architecture is presented as part of this ‘integration simplification’ approach. Current and developing PP&C systems are assessed against a number of information system integration criteria, and the results of a small survey of proprietary packages are presented. The paper concludes that information must be regarded as an enterprise-wide asset, rather than belonging to individual software applications, and that the adoption of relevant standards will enable seamless integration within a three-schema architecture. An increasing number of proprietary packages are adopting standards and methodologies which ease the integration problem significantly.     

An International Pooled Analysis for Obtaining a Benchmark Dose for Environmental Lead Exposure in Children

Lead is a recognized neurotoxicant, but estimating effects at the lowest measurable levels is difficult. An international pooled analysis of data from seven cohort studies reported an inverse and supra‐linear relationship between blood lead concentrations and IQ scores in children. The lack of a clear threshold presents a challenge to the identification of an acceptable level of exposure. The benchmark dose (BMD) is defined as the dose that leads to a specific known loss. As an alternative to elusive thresholds, the BMD is being used increasingly by regulatory authorities. Using the pooled data, this article presents BMD results and applies different statistical techniques in the analysis of multistudy data. The calculations showed only a limited variation between studies in the steepness of the dose‐response functions. BMD results were quite robust to modeling assumptions with the best fitting models yielding lower confidence limits (BMDLs) of about 0.1–1.0 μ g/dL for the dose leading to a loss of one IQ point. We conclude that current allowable blood lead concentrations need to be lowered and further prevention efforts are needed to protect children from lead toxicity.     

精神分裂分析：解析资本主义的新视角——读《反俄狄浦斯：资本主义与精神分裂症》

在《反俄狄浦斯：资本主义与精神分裂症》中，法国当代哲学家吉莱斯·德勒兹与利克斯·瓜塔里认为，弗洛伊德的俄狄浦斯情结是人们心中的欲望源泉，又是资本主义统治的基础。因此，为了使人们能够挣脱资本主义，欲望本能需转向为欲望机器。通过精神分裂分析，他们提出了精神分裂症患者才是“去俄狄浦斯化”的革命代理人，这与马克思分析资本主义造就自己掘墓人的思想如出一辙。