Search results for "city"
showing 10 items of 12465 documents
Innovative method to estimate state of charge of the hydride hydrogen tank: application of fuel cell electric vehicles
2021
International audience; Significant attention has been paid to metal hydrides (MH) as an environmentally friendly and safe way to store hydrogen. This technology has considerable potential for the application of embedded hydrogen storage in fuel cell electric vehicles, but its widespread application faces a major problem in terms of estimating the remaining hydrogen amount in the tank. In this work, a new method is proposed for estimating the state of charge (SoC) of the hydrogen hydride tank (HHT) by application of piezoelectric material. The idea is to cover the entire inner wall of the metal-hydride tank with a layer of piezoelectric material. During the process of hydrogen absorption, t…
Energy harvesting using piezoelectric transducers for suspension systems
2020
Abstract Energy harvesting by using functional materials in suspension systems bear potential to win-back certain (even if low) amounts of vibrational energy, otherwise dissipated via the conventional (passive) dampers. Piezoelectric (PE) ceramics are functional materials that can be used for transforming mechanical energy into electrical and vice versa. In this paper, we study the capabilities and efficiency of energy harvesting (EH) with PE transducers under two different kinds of external excitation: i) Periodic and ii) stochastic. An appropriate nonlinear lumped parameter electromechanical model (LPEM) is brought into the two-port network notation. Laboratory experiments were conducted …
Magnetic field-assisted single-point incremental forming with a magnet ball tool
2021
Abstract This paper describes magnetic field-assisted single-point incremental forming (M-SPIF) with a Nd-Fe-B magnet ball tool. In M-SPIF, the tool driven by magnetic force plastically deforms a sheet. The polarity of the magnet tool helps to make the magnetic force (i.e., forming force) more controllable. In creating a truncated cone, the direction of the magnetic force gradually points more outward as the process progresses, and material is forced outwards from the cone center, increasing thinning in M-SPIF, while the cone center remains undeformed in traditional SPIF. Moreover, M-SPIF creates less localized plastic strain than traditional SPIF while forming the desired geometry.
Application of linear friction welding for joining ultrafine grained aluminium
2020
Abstract Ultrafine grained (UFG) materials are of great potential in industry due to their enhanced mechanical strength and other promising features, such as ability to superplastic deformation or excellent corrosion resistance. Nevertheless, one of the main limitations lies in their low thermal stability, which leads to excessive grain growth at elevated temperature. It influences mainly further processes performed at high temperature, such as joining. It causes detrimental problems during conventional fusion welding, as significant grain growth is observed and therefore the advantages as a result of small average grain size disappear. Therefore, the idea of applying solid state joining pr…
Adaptive Fuzzy Super-Twisting Sliding Mode Control for Microgyroscope
2019
This paper proposes a novel adaptive fuzzy super-twisting sliding mode control scheme for microgyroscopes with unknown model uncertainties and external disturbances. Firstly, an adaptive algorithm is used to estimate the unknown parameters and angular velocity of microgyroscopes. Secondly, in order to improve the performance of the system and the superiority of the super-twisting algorithm, this paper utilizes the universal approximation characteristic of the fuzzy system to approach the gain of the super-twisting sliding mode controller and identify the gain of the controller online, realizing the adaptive adjustment of the controller parameters. Simulation results verify the superiority a…
Estimation of Sway-angle Based on Hybrid State Observer Using Continuous and Discrete Sensing
2019
A hybrid state observer design is presented herein to estimate sway-angle and angular velocity in trolley systems with pendulum. In general, anti-sway control for trolley systems with pendulum such as overhead cranes are designed based on sway-angle signals detected by angular sensors. Opposed to that, a state observer without those sensors is proposed to estimate the sway-angle of the pendulum. A standard linear continuous feedback observer causes estimation error owing to the system nonlinearity and modeling error. This paper proposes a hybrid state observer incorporating discrete sensor signals. In the hybrid state observer, the estimation performance is improved by correcting the state …
Designing Cognitive Cities
2018
The following text intends to give an introduction into some of the basic ideas which determined the conception of this book. Thus, the first part of this article introduces the terms “City”, “Smart City” and “Cognitive City”. The second part gives an overview of design theories and approaches such as Action Design Research and Ontological Design (a concept in-the-making), in order to deduce from a theoretical point of view some of the principles that needs to be taken into account when designing the Cognitive City. The third part highlights some concrete techniques that can be usefully applied to the problem of citizen communication for Cognitive Cities (namely Metaheuristics, Fuzzy Sets a…
A Meta-Model for Intelligent Engineering Design of Complex City
2019
A city is a complex system, requiring the input of multiple disciplines for its (re)design. It shares some properties of two kinds of objects: empirical objects as well as theoretical objects. As city emerges as a complex object for multi-disciplinary studies, it is of the highest importance to adopt a systemic and global approach in order to bring new knowledge to this field. To master the growing complexity of cities and to consider in the same spot heterogeneous ways of thinking of city, we need intellectual tools and models. The goal of this paper is to propose a model for describing engineering modelling knowledge with relationships and transformations between four domains: (1) citizen…
Comparison of fully non-stationary artificial accelerogram generation methods in reproducing seismicity at a given site
2020
Abstract Seismic input modelling is a crucial step when Non-Linear Time-History Analyses (NLTHAs) are performed, the seismic response of structures being highly responsive to the input employed. When natural accelerograms able to represent local seismicity are not available, the use of generated accelerograms is an efficient solution for input modelling. The aim of the present paper is to compare four methods for generating fully non-stationary artificial accelerograms on the basis of a target spectrum, identified using seven recorded accelerograms registered in the neighbourhood of the construction site during a single event, assumed as target accelerograms. For each method, seven accelero…
Hypervisor Memory Introspection and Hypervisor Based Malware Honeypot
2020
Memory acquisition is a tool used in advanced forensics and malware analysis. Various methods of memory acquisition exist. Such solutions are ranging from tools based on dedicated hardware to software-only solutions. We proposed a hypervisor based memory acquisition tool. [22]. Our method supports ASLR and Modern operating systems which is an innovation compared to past methods [27, 36]. We extend the hypervisor assisted memory acquisition by adding mass storage device honeypots for the malware to cross and propose hiding the hypervisor using bluepill technology.