Hyperbolic Minesweeper Is in P

We show that, while Minesweeper is NP-complete, its hyperbolic variant is in P. Our proof does not rely on the rules of Minesweeper, but is valid for any puzzle based on satisfying local constraints on a graph embedded in the hyperbolic plane

Non-Euclidean Video Games: Exploring Player Perceptions and Experiences inside Impossible Spaces

Non-Euclidean geometry has the potential to be used for novel interactions in video games and create virtual spaces that are not physically possible in the real world. To explore how players perceive and experience them in video games, we have adapted two well-known 2D games, Snake and Asteroids to create two versions in addition to the conventional virtual space – with hyperbolic and spherical environments – and conducted a within-subject design user study on all three versions of these games. The results show that experienced Mastery and Control are lower when playing the two non-Euclidean versions while perceived Immersion and Challenge do not differ significantly between these three conditions. We also report on the qualitative findings from our participants, which provide further insights into the perception and experiences of these environments

Databook for human factors engineers. Volume 2 - Common formulas, metrics, definitions

Human factors engineering manual including mathematical formulas, nomographs, conversion tables, units of measurement, and nomenclature

Graph Neural Networks for Graphs with Heterophily: A Survey

Recent years have witnessed fast developments of graph neural networks (GNNs) that have benefited myriads of graph analytic tasks and applications. In general, most GNNs depend on the homophily assumption that nodes belonging to the same class are more likely to be connected. However, as a ubiquitous graph property in numerous real-world scenarios, heterophily, i.e., nodes with different labels tend to be linked, significantly limits the performance of tailor-made homophilic GNNs. Hence, GNNs for heterophilic graphs are gaining increasing research attention to enhance graph learning with heterophily. In this paper, we provide a comprehensive review of GNNs for heterophilic graphs. Specifically, we propose a systematic taxonomy that essentially governs existing heterophilic GNN models, along with a general summary and detailed analysis. Furthermore, we discuss the correlation between graph heterophily and various graph research domains, aiming to facilitate the development of more effective GNNs across a spectrum of practical applications and learning tasks in the graph research community. In the end, we point out the potential directions to advance and stimulate more future research and applications on heterophilic graph learning with GNNs.Comment: 22 page

Mechanologic: Designing Mechanical Devices that Compute

Despite their initial success and impact on the development of the modern computer, mechanical computers were quickly replaced once electronic computers became viable. Recently, there has been increased interest in designing devices that compute using modern and unconventional materials. In this dissertation, we investigate multiple ways to realize a mechanical device that can compute, with a main focus on designing mechanical equivalents for wires and transistors. For our first approach at designing mechanical wires, we present results on the propagation of signals in a soft mechanical wire composed of bistable elements. When we send a signal along bistable wires that do not support infinite signal propagation, we find that signals can propagate for a finite distance controlled by a penetration length for perturbations. We map out various parameters for this to occur, and present results from experiments on wires made of soft elastomers. Our second approach for designing mechanical devices that compute focuses on designing the topology of the configuration space of a linkage. By programming the configuration space through small perturbations of the bar lengths in the linkage, we are able to design a linkage that gates the propagation of a soliton in a Kane-Lubensky chain. This dissertation also includes other results related to the study of small length changes in linkages and an analysis of a version of a mechanical transistor compatible with the soft bistable wires

Sea Mines and Countermeasures: A Bibliography

This compilation was prepared for the Dudley Knox Library, Naval Postgraduate School, Monterey, CA

Catalog of selected heavy duty transport energy management models

A catalog of energy management models for heavy duty transport systems powered by diesel engines is presented. The catalog results from a literature survey, supplemented by telephone interviews and mailed questionnaires to discover the major computer models currently used in the transportation industry in the following categories: heavy duty transport systems, which consist of highway (vehicle simulation), marine (ship simulation), rail (locomotive simulation), and pipeline (pumping station simulation); and heavy duty diesel engines, which involve models that match the intake/exhaust system to the engine, fuel efficiency, emissions, combustion chamber shape, fuel injection system, heat transfer, intake/exhaust system, operating performance, and waste heat utilization devices, i.e., turbocharger, bottoming cycle