Statistical inference for the two-sample problem under likelihood ratio ordering, with application to the ROC curve estimation.

The receiver operating characteristic (ROC) curve is a powerful statistical tool and has been widely applied in medical research. In the ROC curve estimation, a commonly used assumption is that larger the biomarker value, greater severity the disease. In this article, we mathematically interpret "greater severity of the disease" as "larger probability of being diseased." This in turn is equivalent to assume the likelihood ratio ordering of the biomarker between the diseased and healthy individuals. With this assumption, we first propose a Bernstein polynomial method to model the distributions of both samples; we then estimate the distributions by the maximum empirical likelihood principle. The ROC curve estimate and the associated summary statistics are obtained subsequently. Theoretically, we establish the asymptotic consistency of our estimators. Via extensive numerical studies, we compare the performance of our method with competitive methods. The application of our method is illustrated by a real-data example.

Impact of COVID-19 on private driving behavior: Evidence from electric vehicle charging data.

The COVID-19 pandemic has given rise to a major impact on traffic mobility. To implement preventive measures and manage transportation, understanding the transformation of private driving behavior during the pandemic is critical. A data-driven forecasting model is proposed to estimate daily charging demand in the absence of the COVID-19 pandemic by leveraging electric vehicle (EV) charging data from four cities in China. It serves as a benchmark for quantifying the impact of the COVID-19 pandemic on EV charging demand. A vector autoregressive (VAR) model is then used to investigate the dynamic relationship between the changes in charging demand and potential influencing factors. Potential influencing factors are selected from three aspects: public health data, public concern, and the level of industrial activity. The results show that the magnitude of the decline in EV charging demand varied by city during the pandemic. Furthermore, COVID-19 related factors such as daily hospitalizations and national confirmed cases are the primary causes of the decline in charging demand. The research framework of this paper can be generalized to analyze the changes in other driving behaviors during the pandemic. Finally, three policy implications are proposed to assist other countries in dealing with similar events and to stimulate the recovery of the transport system during the post-pandemic period.

Relaxation behavior of shear-induced crystallization precursors in isotactic polypropylene containing sorbitol-based nucleating agents with different nucleating abilities.

The nature of shear-induced crystallization precursors, especially their relaxation behaviour, is an important issue in polymer chemical physics. In our work, relaxation behavior of shear-induced crystallization precursors in isotactic polypropylene containing various sorbitol-based nucleating agents (NAs) with different nucleating abilities was investigated by using both rheological and in situ small angle X-ray scattering (SAXS) methods. Rheological crystallization kinetics results showed that the amount of shear-induced precursors, calculated separately from the total nuclei, decayed exponentially with relaxation time in both pure and nucleated iPP. By fitting the decay of shear-induced precursors with relaxation time, the relaxation rate of precursors in nucleated iPP was found to be slower than that in pure iPP. Interestingly, it further decreased with the increase in the nucleating ability of sorbitol-based NAs. Meanwhile, the life-time of precursors was prolonged in nucleated iPP with increasing nucleating ability. Similar results were also testified by in situ SAXS measurements. By investigating the life-times at different temperatures, the activation energy for the relaxation of precursors was calculated and found to increase with stronger nucleating abilities. Our results demonstrated that sorbitol-based NAs could stabilize the iPP precursors and the effect of stabilization enhanced with the increase in nucleating ability. We believe that our work can not only help better reveal the relaxation behavior of shear-induced precursors but also provides a new perspective for understanding the role of NAs in real processing.

Empathic accuracy in individuals with schizotypal personality traits.

Empirical research using the Empathic Accuracy Task (EAT) has suggested that schizophrenia patients and people with schizotypal personality disorder exhibit lower empathic accuracy than healthy people. However, empathic accuracy in a subclinical sample with high levels of schizotypy has seldom been studied. Our study aimed to investigate empathy in a subclinical sample using the Chinese version of the EAT and a self-report empathy measure. Forty participants with high levels of schizotypy (HS participants) and 40 with low levels of schizotypy (LS participants), as measured by the Schizotypal Personality Questionnaire (SPQ), were recruited. All participants completed the Chinese version of the EAT and the self-report Questionnaire of Cognitive and Affective Empathy. Empathic accuracy (EA) scores and the intra-individual variability of EA scores were calculated. Independent samples t tests and Pearson correlation analyses were performed to examine group differences in empathy and the relationship between empathy and schizotypy respectively. HS participants exhibited reduced EA for both positive and negative videos, and larger intra-individual variability of EA for negative videos than LS participants. However, HS and LS participants did not differ in self-report cognitive empathy. Moreover, the interpersonal dimension of the SPQ was negatively correlated with EAT performance and self-report cognitive empathy in LS participants. Individuals with HS show poorer performance-based EA but relatively intact self-report cognitive empathy. This study provides empirical evidence for the ontogeny of empathy deficits in subclinical populations at risk of developing schizophrenia, supporting early interventions for social cognitive deficits.

High-resolution electric power load data of an industrial park with multiple types of buildings in China.

Considering the growing demand for electricity in industrial parks, understanding their electric power load patterns is critical for improving energy efficiency and ensuring the rational utilization of energy resources. However, the detailed electric power load data of various buildings in industrial parks are rarely available and accessible, which hinders the related studies. In this context, we present the electric power load data of 6 years (from January 1, 2016 to December 31, 2021) for various types of buildings in an industrial park in Suzhou, China. The data are obtained from smart meters and have various time resolutions (i.e., 5 minutes, 30 minutes, and 1 hour). This work describes the data collection, processing process, and different imputation methods. The high-resolution electric power load data can be used for various research tasks, including load prediction, load pattern recognition, anomaly detection, and demand response strategy development.