Katherine Price | Searcharxiv

arXiv2022

How Much Does Home Field Advantage Matter in Soccer Games? A Causal Inference Approach for English Premier League Analysis

In many sports, it is commonly believed that the home team has an advantage over the visiting team, known as the home field advantage. Yet its causal effect on team performance is largely unknown. In this paper, we propose a novel causal inference approach to study the causal effect of home field advantage in English Premier League. We develop a hierarchical causal model and show that both league level and team level causal effects are identifiable and can be conveniently estimated. We further develop an inference procedure for the proposed estimators and demonstrate its excellent numerical performance via simulation studies. We implement our method on the 2020-21 English Premier League data and assess the causal effect of home advantage on eleven summary statistics that measure the offensive and defensive performance and referee-assessed disciplinary outcomes. We find that the home field advantage resides more heavily in offensive statistics than it does in defensive or referee statistics. We also find evidence that teams that had lower rankings retain a higher home field advantage.

stat.AP↗

arXiv2018

Immunity to Scaling in MoS2 Transistors Using Edge Contacts

Atomically thin two-dimensional (2D) materials are promising candidates for sub-10 nm transistor channels due to their ultrathin body thickness, which results in strong electrostatic gate control. Properly scaling a transistor technology requires reducing both the channel length (distance from source to drain) and the contact length (distance that source and drain interface with semiconducting channel). Contact length scaling remains an unresolved epidemic for transistor scaling, affecting devices from all semiconductors, from silicon to 2D materials. Here, we show that clean edge contacts to 2D MoS2 provide immunity to the contact-scaling problem, with performance that is independent of contact length down to the 20 nm regime. Using a directional ion beam, in situ edge contacts of various metal-MoS2 interfaces are studied. Characterization of the intricate edge interface using cross-sectional electron microscopy reveals distinct morphological effects on the MoS2 depending on its thickness, from monolayer to few-layer films. Chromium is found to outperform other metals in the edge contact scheme, which is attributed to the shorter Cr-MoS2 bond length. Compared to scaled top contacts with 20 nm contact length, in situ edge contacts yield better performance with an effective contact length of ~ 1 nm and 18 times higher carrier injection efficiency. The in situ edge contacts also exhibit ~8 times higher performance compared to the best-reported edge contacts. Our work provides experimental evidence for a solution to contact scaling in transistors, using 2D materials with clean edge contact interfaces, opening a new way of designing devices with 2D materials.

cond-mat.mtrl-sci↗