A Better Confidence Interval for Kappa (κ) on Measuring Agreement between Two Raters with Binary Outcomes

Abstract

Although the kappa statistic is widely used in measuring interrater agreement, it is known that the standard confidence interval estimation behaves poorly in small samples and for nonzero kappas. Efforts have been made to improve the estimation through transformation and Edgeworth expansion (Flack 1987). The results remain unsatisfactory when kappa is far from 0, however, even with the sample size as large as 100. In this article we reparameterize the kappa statistic to reveal its relationship with the marginal probability of agreement. The reparameterization not only gives a more meaningful interpretation of kappa but also clearly demonstrates that the range of kappa depends on the marginal probabilities. Various two- and three-dimensional plots are shown to illustrate the relationship among these parameters. The immediate application is to construct a new confidence interval based on the profile variance and reparameterization. Extensive simulation studies show that the new confidence interval performs very well in almost all parameter settings even when other methods fail.     

99 + matches but a spark ain’t one: Adverse psychological effects of excessive swiping on dating apps

Studies showed adverse experiences related to the use of dating applications such as Tinder. However, it remains unclear by which mechanism and under which conditions dating app use has undesired effects. As a mechanism, we investigated excessive swiping, operationalized as youth’s mental preoccupation with profile browsing and swiping compulsivity. As moderators, we investigated swiping in assessment (i.e., critically evaluating profiles), and locomotion (i.e., taking intuitive gut decisions) modes. To this end, we surveyed a quota-sample of 464 transition age dating app users (16–25 years old). Moderated mediation analyses showed that dating app use was associated with excessive swiping, which was in turn linked to a) upward social comparison, b) fear of being single, and c) partner choice overload. In conclusion, frequent dating app use was related to undesired outcomes only when it was related to excessive swiping. Neither assessment, nor locomotion mode moderated these relationships; thus, excessive swiping is detrimental for young dating app users’ well-being, no matter how they swipe.     

浅析反馈式编译技术

基于profiling的反馈式编译优化是一种有效的编译优化模式,它通过程序运行时的剖面信息来指导对代码的优化。文章总结了实现这种模式的一般流程,所遇到的问题和解决方法。     

Profile measurement of a one-dimensional phase boundary sample using a single shot phase-step method

Phase shifting interferometry is a preferred technique for high-resolution phase profile measurement, but the difficulty in generating the requested shifted pattern has limited the use of the technique to low-noise environment and in case accurate calibration of the phase shifting device is available. In the present experiment, a sample having one-dimensional straight phase boundary is mounted in one arm of an interferometer. One single image of the fringe pattern is recorded, a simple image process is applied generating phase shifted patterns from the original image. Using the appropriate phase shift algorithms, a phase map of the sample is obtained which gives a quantitative measurement of the topographical structure with the resolution of the phase shift method but a single shot recorded pattern.     

树的补图的区间图完全化问题

一个图G的区间图完全化问题包含两类子问题:侧廓问题和路宽问题,分别表示为P(G)和PW(G),其中侧廓问题是寻求G的一个边数最小的区间超图;路宽问题是寻求G的一个团数最小的区间超图.这两类子问题分别在数值代数、VLSI-设计和算法图论等学科领域中有重要的应用.对一般图来说,两类子问题都是NP-完全问题;但是对一些特殊图类来说,它们在多项式时间内可解.本文给出了树T的补图的具体侧廓和路宽值.     

Likelihood-based Inference for the Ratios of Regression Coefficients in Linear Models

We consider the standard linear multiple regression model in which the parameter of interest is the ratio of two regression coefficients. Our setup includes a broad range of applications. We show that the 1− α confidence interval for the interest parameter based on the profile, conditional profile, modified profile or adjusted profile likelihood can potentially become the entire real line, while appropriately chosen integrated likelihoods do not suffer from this drawback. We further explore the asymptotic length of confidence intervals in order to compare integrated likelihood-based proposals. The analysis is facilitated by an orthogonal parameterization.     

GC^1双螺杆泵线型

摆线和渐开线在机械别件设计中起着重要作用。双螺杆泵转子曲面是两个螺旋面，它的横截面线型是由摆线和开线组合而成，它们的连续接是不光滑的。本文提出了一种ＧＣ＾１的计算机辅助设计的新方法。     

半绝缘砷化镓材料的离子注入

概述了ＧａＡｓ材料的离子注入及有关的问题，如损伤退火，掺杂剂激活和载流子分布等。另外，还提出了几种改善掺杂效率的方法。     

Kinetics of swelling of polyacrylamide gels: concentration profiles and effect of an imposed strain

The time course of the concentration profile of a spherical gel has been measured during a swelling experiment, and compared to the theoretical expressions. The swelling of a cylindrical gel under imposed strain has been studied both theoretically and experimentally. This provides a new method of determination of the ratio of the shear modulus over the osmotic longitudinal modulus.     

具有内吸收和耦合局部化源的抛物组的渐近分析

该文是关于一类具有内吸收和耦合局部化源的抛物组解的渐近分析的研究.作者证明了解在区域内处处blow-up的结论,得到不同非线性指标占优情形下三种可能的blow-up速率,并借助于所引入的特征代数方程组给出这三种速率的简洁表示.特别地,作者对弱吸收情形,给出解的一致blow-up profile;对于两种非平衡吸收情形,得到与吸收项指标有关的blow-up速率,这与单个方程情形(其速率均与吸收项指标无关)的已有结果截然不同.以上结果的证明主要依据scaling方法,以及对于模型非线性指标的完全分类.