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Topic Review
Indefinite Lifespan
Indefinite lifespan (also known as indefinite life extension or bio-indefinite) is a term used in the life extension movement and transhumanism to refer to the hypothetical longevity of humans (and other life-forms) under conditions in which ageing is effectively and completely prevented and treated. Their lifespans would be "indefinite" (that is, they would not be "immortal"), because protection from the effects of aging on health does not guarantee survival. Such individuals would still be susceptible to death by disease, starvation, accidents, or deliberate killing, but not death from aging. Semantically, "indefinite lifespan" is more accurate than "immortality" which, especially in religious contexts, implies an inability to die.
  • 1.3K
  • 26 Oct 2022
Topic Review
Robust Outlier-Adaptive Filtering
With the advent of unmanned aerial vehicles (UAVs), a major area of interest in the research field of UAVs has been vision-aided inertial navigation systems (V-INS). In the front-end of V-INS, image processing extracts information about the surrounding environment and determines features or points of interest. With the extracted vision data and inertial measurement unit (IMU) dead reckoning, the most widely used algorithm for estimating vehicle and feature states in the back-end of V-INS is an extended Kalman filter (EKF). An important assumption of the EKF is Gaussian white noise. In fact, measurement outliers that arise in various realistic conditions are often non-Gaussian. A lack of compensation for unknown noise parameters often leads to a serious impact on the reliability and robustness of these navigation systems. To compensate for uncertainties of the outliers, we require modified versions of the estimator or the incorporation of other techniques into the filter. The main purpose of this paper is to develop accurate and robust V-INS for UAVs, in particular, those for situations pertaining to such unknown outliers. Feature correspondence in image processing front-end rejects vision outliers, and then a statistic test in filtering back-end detects the remaining outliers of the vision data. For frequent outliers occurrence, variational approximation for Bayesian inference derives a way to compute the optimal noise precision matrices of the measurement outliers. The overall process of outlier removal and adaptation is referred to here as “outlier-adaptive filtering”. Even though almost all approaches of V-INS remove outliers by some method, few researchers have treated outlier adaptation in V-INS in much detail. Here, results from flight datasets validate the improved accuracy of V-INS employing the proposed outlier-adaptive filtering framework.
  • 1.3K
  • 30 Oct 2020
Topic Review
Froth Washing in Flotation
Froth flotation is a mineral processing technique that is popular when processing low-grade ores. It involves introducing chemically treated, finely ground ore in the form of a slurry into a flotation cell where the air is also added in the form of bubbles. The cell is agitated resulting in the air bubbles rising to the top and creating a froth, as bubbles rise, hydrophilic particles attach to the rising bubbles creating a froth which is collected in the weir or using launders for further treatment. The froth is washed using various froth-washing techniques to reduce entrainment and improve the grade of the froth. Froth washing can be achieved using froth washing jets or froth washing trays, this can be achieved internally/externally with regards to the position in the froth layer.
  • 1.3K
  • 30 Nov 2022
Topic Review
Fused Filament Fabrication Process
Three-dimensional printing (3DP), also known as additive manufacturing (AM), has rapidly evolved over the past few decades. Researchers around the globe have been putting their efforts into AM processes improvement and materials development. One of the most widely used extrusion-based technology under AM processes is Fused Deposition Modeling (FDM), also known as Fused Filament Fabrication (FFF). Numerical simulation tools are being employed to predict the FFF process complexities and material behavior. These tools allow exploring candidate materials for their potential use in the FFF process and process improvements. The prime objective of this study is to provide a comprehensive review of state-of-the-art scientific achievements in numerical simulations of the FFF process for polymers and their composites.
  • 1.3K
  • 30 Nov 2021
Topic Review
Traffic Flow Prediction
The accurate and effective prediction of the traffic flow of vehicles plays a significant role in the construction and planning of signalized road intersections. The application of artificially intelligent predictive models in the prediction of the performance of traffic flow has yielded positive results. However, much uncertainty still exists in the determination of which artificial intelligence methods effectively resolve traffic congestion issues, especially from the perspective of the traffic flow of vehicles at a four-way signalized road intersection.
  • 1.3K
  • 08 Oct 2021
Topic Review
Carbon Nanofibers
Carbon nanofibers are nano-sized fibers that have a high degree of crystalline orientation. In recent years, ecological issues have led to the search for new green materials from biomass as precursors for producing carbon materials. Such green materials are more attractive than traditional petroleum-based materials, which are environmentally harmful and non-biodegradable.
  • 1.3K
  • 02 May 2021
Topic Review
Pineapple Leaf Fiber
Evidence-based research had shown that elevated alkali treatment of pineapple leaf fiber(PALF) compromised the mechanical properties of the fiber. In this work, PALF was subjected todifferential alkali concentrations: 1, 3, 6, and 9% wt/wt to study the influence on the mechanicaland crystal properties of the fiber. The crystalline and mechanical properties of untreated and alkali-treatedPALF samples were investigated by X-ray diffractometry (XRD), Fourier transforms infraredspectroscopy (FTIR), and tensile testing analysis. The XRD results indicated that crystal propertiesof the fibers were modified with 6% wt/wt alkali-treated PALF recording the highest crystallinityand crystallite size of 76% and 24 nm, respectively. The FTIR spectra suggested that all alkali-treatedPALF samples underwent lignin and hemicellulose removal to varying degrees. An increase in thecrystalline properties improved the mechanical properties of the PALF treated with alkali at 6%wt/wt, which has the highest tensile strength (1620 MPa). Although the elevated alkali treatmentresulted in decreased mechanical properties of PALF, crystallinity generally increased. The findingsrevealed that the mechanical properties of PALF not only improve with increasing crystallinity andcrystallite size but are also dependent on the intermediate bond between adjacent cellulose chains.
  • 1.3K
  • 20 Aug 2021
Topic Review
Yandex Self-Driving Car
Yandex self-driving car (Yandex Self-Driving Group) is a robotaxi project of the Russian-based internet corporation Yandex. The first driverless prototype launched in May 2017. As of 2018, functional service was launched in Russia with prototypes also being tested in Israel and the US. In 2019, Yandex revealed autonomous delivery robots based on the same technology stack as the company's self-driving cars. Since 2020, autonomous robots have been delivering food, groceries and parcels in Russia and the USA. In 2020, the self-driving project was spun-off into a standalone company under the name of Yandex Self-Driving Group (Yandex SDG).
  • 1.3K
  • 27 Oct 2022
Topic Review
Harmonic Radio Frequency Identification
Harmonic Radio Frequency Identification (RFID) system operates at two different frequencies for uplink and downlink communication unlike conventional RFID systems. Operating at two frequencies provides many operational advantages over RFID system.
  • 1.3K
  • 22 Apr 2021
Topic Review Peer Reviewed
Metal Nanoparticles as Free-Floating Electrodes
Colloidal metal nanoparticles in an electrolyte environment are not only electrically charged but also electrochemically active objects. They have the typical character of metal electrodes with ongoing charge transfer processes on the metal/liquid interface. This picture is valid for the equilibrium state and also during the formation, growth, aggregation or dissolution of nanoparticles. This behavior can be understood in analogy to macroscopic mixed-electrode systems with a free-floating potential, which is determined by the competition between anodic and cathodic partial processes. In contrast to macroscopic electrodes, the small size of nanoparticles is responsible for significant effects of low numbers of elementary charges and for self-polarization effects as they are known from molecular systems, for example. The electrical properties of nanoparticles can be estimated by basic electrochemical equations. Reconsidering these fundamentals, the assembly behavior, the formation of nonspherical assemblies of nanoparticles and the growth and the corrosion behavior of metal nanoparticles, as well as the formation of core/shell particles, branched structures and particle networks, can be understood. The consequences of electrochemical behavior, charging and self-polarization for particle growth, shape formation and particle/particle interaction are discussed.
  • 1.2K
  • 13 Apr 2022
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