An unconditional maximum likelihood test for a unit root

We investigate a test for unit roots in autoregressive time series based on maximization of the unconditional likelihood. This is the likelihood function appropriate for stationary time series. While this function is the true likelihood only under the stationary alternative, it can nevertheless be maximized for any data including data from a unit root process. It thus gives a way to test for unit roots, provided percentill~s can be calculated. For models with estimated means, the power of the new test is better than that of some currently popular tests

A primer on cointegration with an application to money and income

Money theory ; Income ; Cointegration

Recency Effect in College Student Course Evaluations

Universities depend on faculty evaluations to substantiate tenure and promotion decisions and it is well known that student ratings are a critical source of information for this process. Of recent concern in course evaluations is recency effect, a rating error that occurs when more weight is assigned to activities that are closer to the time of formal appraisal. Quantitative procedures used in this study revealed that students who were either trained in recency effect and kept a course diary or kept a course diary only were sensitive to this type of error on a measure of teaching skill, but not course organization. Qualitative procedures also revealed that students were aware of recency effect once it was defined. Accessed 22,308 times on https://pareonline.net from June 15, 2005 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

HRTEM study of a new non-stoichiometric BaTiO(3-δ) structure

BaTiO3-based multilayer ceramic capacitors (MLCCs) with Ni internal electrodes are co-fired in reducing atmospheres to avoid oxidation of the electrode. Although dielectric materials are doped by acceptor, donor and amphoteric dopants to minimize the oxygen vacancy content, there is still a large concentration of oxygen vacancies that are accommodated in the BaTiO3 active layers. In general, ABO3 perovskites demonstrates a strong ability to accommodate the oxygen vacancies and maintain a regular pseudo-cubic structure. Oxygen deficient barium titanate can be transformed to a hexagonal polymorph (h-BT) at high temperatures1,2. In this paper, we report the new modulated and long range ordered structures of non-stoichiometric BaTiO3-δ that are observed in the electrically degraded Ni-BaTiO3 MLCCs at low temperature

Introduction to special section on Recent Advances in the Study of Optical Variability in the Near‐Surface and Upper Ocean

Optical variability occurs in the near‐surface and upper ocean on very short time and space scales (e.g., milliseconds and millimeters and less) as well as greater scales. This variability is caused by solar, meteorological, and other physical forcing as well as biological and chemical processes that affect optical properties and their distributions, which in turn control the propagation of light across the air‐sea interface and within the upper ocean. Recent developments in several technologies and modeling capabilities have enabled the investigation of a variety of fundamental and applied problems related to upper ocean physics, chemistry, and light propagation and utilization in the dynamic near‐surface ocean. The purpose here is to provide background for and an introduction to a collection of papers devoted to new technologies and observational results as well as model simulations, which are facilitating new insights into optical variability and light propagation in the ocean as they are affected by changing atmospheric and oceanic conditions

What is the Connection Between Issues, Bugs, and Enhancements? (Lessons Learned from 800+ Software Projects)

Agile teams juggle multiple tasks so professionals are often assigned to multiple projects, especially in service organizations that monitor and maintain a large suite of software for a large user base. If we could predict changes in project conditions changes, then managers could better adjust the staff allocated to those projects.This paper builds such a predictor using data from 832 open source and proprietary applications. Using a time series analysis of the last 4 months of issues, we can forecast how many bug reports and enhancement requests will be generated next month. The forecasts made in this way only require a frequency count of this issue reports (and do not require an historical record of bugs found in the project). That is, this kind of predictive model is very easy to deploy within a project. We hence strongly recommend this method for forecasting future issues, enhancements, and bugs in a project.Comment: Accepted to 2018 International Conference on Software Engineering, at the software engineering in practice track. 10 pages, 10 figure