Accuracy,confidence and consensus in bayesian hypothesis inference

Interest centres on a group of statisticians , each supplied with the same n sample datapoint sandmaking formal Bayesian inference with a common likelihood function but differing prior knowledge and utility functions.

Definitions are proposed which quantify, in a commensurable way, the inference processes of “accuracy”, “confidence” and “consensus” for the case of hypothesis inference with a fixed sample size n.

The general significance of comparing the three quantifiers is considered. As n increases the asymptotic behaviour of the quantifiers is evaluated and it is found that the three rates of convergence are of the same order as a function of n. The results are interpreted and some of their implications are discussed.     

Dependence Between Two Diagnostic Tests with Copula Function Approach: A Simulation Study

The study of the dependence between two medical diagnostic tests is an important issue in health research since it can modify the diagnosis and, therefore, the decision regarding a therapeutic treatment for an individual. In many practical situations, the diagnostic procedure includes the use of two tests, with outcomes on a continuous scale. For final classification, usually there is an additional “gold standard” or reference test. Considering binary test responses, we usually assume independence between tests or a joint binary structure for dependence. In this article, we introduce a simulation study assuming two dependent dichotomized tests using two copula function dependence structures in the presence or absence of verification bias. We compare the test parameter estimators obtained under copula structure dependence with those obtained assuming binary dependence or assuming independent tests.     

Partial and inverse autocorrelations in portmanteau-type tests for time series

We present a decomposition of the correlation coefficient between x_t and x_t?k into three terms that include the partial and inverse autocorrelations. The first term accounts for the portion of the autocorrelation that is explained by the inner variables {x_t?1 , x_t?2 , …, x _{t? k+1}}, the second one measures the portion explained by the outer variables {x _t+1, x _t+2, } ∪ {x _t?k?1, x _t?k?2,…} and the third term measures the correlation between x _t and x_t?k given all other variables. These terms, squared and summed, can form the basis of three portmanteau-type tests that are able to detect both deviation from white noise and lack of fit of an entertained model. Quantiles of their asymptotic sample distributions are complicated to derive at an adequate level of accuracy, so they are approximated using the Monte Carlo method. A simulation experiment is carried out to investigate significance levels and power of each test, and compare them to the portmanteau test.     

Fiddling while the planet burns? COP25 in perspective

ABSTRACT

With fires, storms, social protests, and climate strikes sweeping the world, 2019 should have been a tipping point in how the world responds to global heating. This was the backdrop to the COP25 climate change summit which took place in Madrid in December 2019. This paper assesses the outcomes of the meeting and the path towards the critically important meeting in Glasgow at the end of 2020. It analyses and explains the key points of contention over levels of ambition, the rules which should govern global carbon markets and sensitive issues such as loss and damage associated with the impacts of climate change. The analysis is situated within a broader geopolitical and economic context of right-wing populism, deepening forms of marketization and financialization of responses to climate change and against a background of a world increasingly feeling the effects of the climate crisis.     

Diagnostic sequence of cocaine use disorder in relation to other mental health conditions among college students

Abstract

Objective: Cocaine use is increasing. Comorbidities and diagnostic sequencing are needed among college students to inform treatment of cocaine use disorder (CUD). Method: Using electronic medical records from the psychiatric clinic at the student health care center of a large, public university from 2005 to 2015, patients diagnosed with CUD were identified. Their top mental health conditions were identified and assessed to see whether the first diagnosis of these conditions was made (1) before, (2) at the same time as, or (3) after the first diagnosis of CUD. Results: Among the 50 CUD patients, their most common mental health comorbidities were alcohol use disorder, anxiety, depression, and cannabis use disorder. Anxiety and depression were likely to be diagnosed before CUD; alcohol and cannabis use disorders were likely to be diagnosed concurrently with CUD. Conclusion: Diagnostic sequencing can be used to inform screening, workup, and treatment for patients with CUD.     

Estimation of discrete survival function for error‐prone diagnostic tests

The product limit or Kaplan‐Meier (KM) estimator is commonly used to estimate the survival function in the presence of incomplete time to event. Application of this method assumes inherently that the occurrence of an event is known with certainty. However, the clinical diagnosis of an event is often subject to misclassification due to assay error or adjudication error, by which the event is assessed with some uncertainty. In the presence of such errors, the true distribution of the time to first event would not be estimated accurately using the KM method. We develop a method to estimate the true survival distribution by incorporating negative predictive values and positive predictive values, into a KM‐like method of estimation. This allows us to quantify the bias in the KM survival estimates due to the presence of misclassified events in the observed data. We present an unbiased estimator of the true survival function and its variance. Asymptotic properties of the proposed estimators are provided, and these properties are examined through simulations. We demonstrate our methods using data from the Viral Resistance to Antiviral Therapy of Hepatitis C study.     

论职务科技成果转化利益分配的约定优先原则

利益驱动是职务科技成果有效转化的关键因素之一,合理的利益分配需尊重当事人的意思自治,遵循约定优先原则。约定优先原则有利于厘清复杂的利益关系、符合私法意思自治的法理、能克服法律规定之不足。约定有效是约定优先原则适用的前提,对其效力判断主要依据合同法和劳动法的相关规定。职务科技成果转化利益分配的约定不受制于法定最低标准（除非为强制性标准);利益分配约定的合理性审查,应以形式审查为主。同时,基于雇佣双方地位不平等,应对约定优先原则加以限制,以平衡各方主体的利益诉求,促进职务科技成果转化。     

电子商务格式合同的法律规制——以奇虎360公司和腾讯公司（QQ）的网络纷争为视点

奇虎360公司和腾讯公司的网络纠纷再一次提出了电子商务格式合同的规范问题,电子商务合同中的网上点击合同和网上软件拆封合同在给网络用户提供便利的同时,其自身条款的格式化、电子化特点也引发了电子商务交易中的一系列矛盾,对用户的隐私和其他合法权益构成了极大威胁。对电子商务格式合同的规范应当从事前的规制和事后的救济两方面入手,在商家义务、用户权利和第三方监督机制等方面加以完善,同时配以违约后的争议在线解决和在线投诉网站,规范取证方法和举证责任的方式,双管齐下从而全面保护用户的各项权益。     

快速分层切换移动IPv6协议技术性能的分析和比较

随着互联网和无线移动通信技术的快速发展,越来越多的用户使用移动终端接入互联网,无线移动接入技术与IPv6结合起来成为目前的研究热点。通过分析基于移动IPv6协议的分层切换技术,比较其技术之间的性能,结合实际应用价值,给出了分析比较的结论。     

A sequential conditional probability ratio test procedure for comparing diagnostic tests

In this paper, we derive sequential conditional probability ratio tests to compare diagnostic tests without distributional assumptions on test results. The test statistics in our method are nonparametric weighted areas under the receiver-operating characteristic curves. By using the new method, the decision of stopping the diagnostic trial early is unlikely to be reversed should the trials continue to the planned end. The conservatism reflected in this approach to have more conservative stopping boundaries during the course of the trial is especially appealing for diagnostic trials since the end point is not death. In addition, the maximum sample size of our method is not greater than a fixed sample test with similar power functions. Simulation studies are performed to evaluate the properties of the proposed sequential procedure. We illustrate the method using data from a thoracic aorta imaging study.