8,503 research outputs found
First-principles methodology for quantum transport in multiterminal junctions
We present a generalized approach for computing electron conductance and I-V
characteristics in multiterminal junctions from first-principles. Within the
framework of Keldysh theory, electron transmission is evaluated employing an
O(N) method for electronic-structure calculations. The nonequilibrium Green
function for the nonequilibrium electron density of the multiterminal junction
is computed self-consistently by solving Poisson equation after applying a
realistic bias. We illustrate the suitability of the method on two examples of
four-terminal systems, a radialene molecule connected to carbon chains and two
crossed carbon chains brought together closer and closer. We describe charge
density, potential profile, and transmission of electrons between any two
terminals. Finally, we discuss the applicability of this technique to study
complex electronic devices.Comment: Will be coming out in JCP soo
Flash-point prediction for binary partially miscible mixtures of flammable solvents
Flash point is the most important variable used to characterize fire and explosion hazard of liquids. Herein, partially miscible mixtures are presented within the context of liquid-liquid extraction processes. This paper describes development of a model for predicting the flash point of binary partially miscible mixtures of flammable solvents. To confirm the predictive efficacy of the derived flash points, the model was verified by comparing the predicted values with the experimental data for the studied mixtures: methanol + octane; methanol + decane; acetone + decane; methanol + 2,2,4-trimethylpentane; and, ethanol + tetradecane. Our results reveal that immiscibility in the two liquid phases should not be ignored in the prediction of flash point. Overall, the predictive results of this proposed model describe the experimental data well. Based on this evidence, therefore, it appears reasonable to suggest potential application for our model in assessment of fire and explosion hazards, and development of inherently safer designs for chemical processes containing binary partially miscible mixtures of flammable solvents
Contextualized Robot Navigation
In order to improve the interaction between humans and robots, robots need to be able to move about in a way that is appropriate to the complex environments around them. One way to investigate how the robots should move is through the lens of theatre, which provides us with ways to analyze the robot\u27s movements and the motivations for moving in particular ways. In particular, this has proven useful for improving robot navigation. By altering the costmaps used for path planning, robots can navigate around their environment in ways that incorporate additional contexts. Experimental results with user studies have shown altered costmaps to have a significant effect on the interaction, although the costmaps must be carefully tuned to get the desired effect. The new layered costmap algorithm builds on the established open-source navigation platform, creating a robust system that can be extended to handle a wide range of contextual situations
Cyber Insurance for Heterogeneous Wireless Networks
Heterogeneous wireless networks (HWNs) composed of densely deployed base
stations of different types with various radio access technologies have become
a prevailing trend to accommodate ever-increasing traffic demand in enormous
volume. Nowadays, users rely heavily on HWNs for ubiquitous network access that
contains valuable and critical information such as financial transactions,
e-health, and public safety. Cyber risks, representing one of the most
significant threats to network security and reliability, are increasing in
severity. To address this problem, this article introduces the concept of cyber
insurance to transfer the cyber risk (i.e., service outage, as a consequence of
cyber risks in HWNs) to a third party insurer. Firstly, a review of the
enabling technologies for HWNs and their vulnerabilities to cyber risks is
presented. Then, the fundamentals of cyber insurance are introduced, and
subsequently, a cyber insurance framework for HWNs is presented. Finally, open
issues are discussed and the challenges are highlighted for integrating cyber
insurance as a service of next generation HWNs.Comment: IEEE Communications Magazine (Heterogeneous Ultra Dense Networks
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