Video calling is one of the most energy-intensive features in apps requiring the simultaneous operation of the mobile camera, display screen, audio speaker, and internet services. This feature impacts a smartphone battery's runtime and lifetime. This paper is the first of its kind experimental study, which quantifies the operating profile (discharge current, temperature, and terminal voltage) of video call feature in multiple widely used social media apps, which include WhatsApp, Facebook Messenger, Zoom, Skype, WeChat, Google Hangouts, Imo and Viber.
View Article and Find Full Text PDFThe wetting kinetics of nickel-based filler metal (BNi2) over selective laser-melted Ti-6Al-4V (SLMed TC4) titanium alloy in a protective argon atmosphere is experimentally investigated using a real-time in situ hot stage equipped with an optical microscope. The spreading processes at different temperatures are similar, and the overall wetting/spreading process can be roughly divided into three stages: (i) an initial stage, (ii) a rapid spreading stage, and (iii) an asymptotic stage. Moreover, the wetting kinetics of the BNi2/SLMed TC4 system can be expressed by empirical power exponential function with = ~1.
View Article and Find Full Text PDFElectromagnetic coils are a key component in a variety of systems and are widely used in many industries. Because their insulation usually fails suddenly and can have catastrophic effects, degradation monitoring of coil insulation systems plays a vital role in avoiding unexpected machine shutdown. The existing insulation degradation monitoring methods are based on assessing the change of coil high-frequency electrical parameter response, whereas the effects of the insulation failure mechanisms are not considered, which leads to inconsistency between experimental results.
View Article and Find Full Text PDFThe threat of a malicious attack is one of the major security problems in complex networks. Resilience is the system-level self-adjusting ability of a complex network to retain its basic functionality and recover rapidly from major disruptions. Despite numerous heuristic enhancement methods, there is a research gap in maximizing network resilience: current heuristic methods are designed to immunize vital nodes or modify a network to a specific onion-like structure and cannot maximize resilience theoretically via network structure.
View Article and Find Full Text PDFAutonomous vehicles are playing an increasingly importance in support of a wide variety of critical events. This paper presents a novel autonomous health management scheme on rail vehicles driven by permanent magnet synchronous motors (PMSMs). Firstly, the PMSMs are modeled based on first principle to deduce the initial profile of pneumatic braking (p-braking) force, then which is utilized for real-time demagnetization monitoring and degradation prognosis through similarity-based theory and generate prognosis-enhanced p-braking force strategy for final optimal control.
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