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Rapid deployment of wind and solar energy generation is going to result in a series of new problems with regards to the reliability of our electrical grid in terms of outages, cost, and life-time, forcing us to promptly deal with the challenging restructuring of our energy systems. Increased penetration of fluctuating renewable energy resources is a challenge for the electrical grid. Proposing solutions to deal with this problem also impacts the functionality of large generators. The power electronic generator interactions, multi-domain modelling, and reliable monitoring systems are examples of new challenges in this field. This book presents some new modelling methods and technologies for renewable energy generators including wind, ocean, and hydropower systems. |
This study aims to show how supporting new business formation could promote the emergence of new ties in the knowledge network. Stimulating start-ups is conducive to the innovation system and economic development, however, we show how it has additional beneficial effects by the increasing the density of the innovation network. An innovation network is a complex socioeconomic phenomenon, which emerges from the decisions of many heterogeneous agents, that justifies the use of an agent-based model (ABM). We introduce an application of an ABM that is appropriate for simulating network formation among organizations. Agents are placed in the two-dimensional abstract social space where they are moving toward each other to find cooperation partners, following the gravity principle. |
In this paper, we present an application of the viscosity approximation type iterative method introduced by Nandal et al. (Iteration Process for Fixed Point Problems and Zeros of Maximal Monotone Operators, Symmetry, 2019) to visualize and analyse the Julia and Mandelbrot sets for a complex polynomial of the type T(z)=zn+pz+r
, where p,r∈C, and n≥2. This iterative method has many applications in solving various fixed point problems. We derive an escape criterion to visualize Julia and Mandelbrot sets via the proposed viscosity approximation type method. |
Research shows that marketing investments play a pivotal role in a firm’s own bankruptcy. However, there are even more firms that are not confronting bankruptcy themselves yet face spillovers from a rival’s bankruptcy. For such firms, it remains unknown whether their marketing investments affect these spillovers. We show that, in contrast to their generally positive effects in other contexts, advertising and R&D can either help or harm in the context of bankruptcy spillovers. The difference hinges on the industry’s growth and concentration. Advertising decreases (increases) a firm’s stock return when its rival files for bankruptcy in a low- (high-) growth industry and R&D decreases (increases) the stock return in a low- (high-) concentration industry. |
In this paper, we study the problem of collective and emergent sensing with a flying robot swarm in which social interactions among individuals lead to following the gradient of a scalar field in the environment without the need of any gradient sensing capability. We proposed two methods—desired distance modulation and speed modulation—with and without alignment control. In the former, individuals modulate their desired distance to their neighbors and in the latter, they modulate their speed depending on the social interactions with their neighbors and measurements from the environment. |
A morph is a continuous transformation between two representations of a graph. We consider the problem of morphing between contact representations of a plane graph. In an F-contact representation of a plane graph G, vertices are realized by internally disjoint elements from a family F of connected geometric objects. Two such elements touch if and only if their corresponding vertices are adjacent. These touchings also induce the same embedding as in G. In a morph between two F-contact representations we insist that at each time step (continuously throughout the morph) we have an F-contact representation. |
Hydrophilic polymer coatings on artificial implants generate excellent tribological properties. The friction properties of polymer coatings are affected by salt ion factors. Herein, the atomic force microscopy (AFM) was used to show that the superlubricity was achieved between poly(vinylphosphonic acid) (PVPA)-modified Ti6Al4V and polystyrene (PS) microsphere probe lubricated with monovalent salt solutions (LiCl, NaCl, KCl, and CsCl). Considering that adhesion is an important cause of friction changes, the AFM was further utilized to obtain adhesion between friction pairs in different salt solutions. The results indicated that the larger the cation radius in the lubricant, the smaller the adhesion, and the lower the friction coefficient of the PVPA coating. |
Heron of Alexandria is a well-known author in the field of mathematics and engineering, but his work is of great interest for understanding ancient construction problems related to architecture. The formulas translated and commented on by Heiberg (1914a, b) are analyzed through geometric diagrams and applied to famous Roman domed architecture. |
We prove limit laws for infinite horizon planar periodic Lorentz gases when, as time n tends to infinity, the scatterer size ρ may also tend to zero simultaneously at a sufficiently slow pace. In particular we obtain a non-standard Central Limit Theorem as well as a Local Limit Theorem for the displacement function. To the best of our knowledge, these are the first results on an intermediate case between the two well-studied regimes with superdiffusive nlogn−−−−−√ scaling (i) for fixed infinite horizon configurations—letting first n→∞ and then ρ→0—studied e.g. by Szász and Varjú (J Stat Phys 129(1):59–80, 2007) and (ii) Boltzmann–Grad type situations—letting first ρ→0
and then n→∞—studied by Marklof and Tóth (Commun Math Phys 347(3):933–981, 2016) . |
The past decades have seen an exponential growth in the amount of data which is produced by individuals. Smartphones which capture images, videos and sensor data have become commonplace, and wearables for fitness and health are growing in popularity. Lifelog retrieval systems aim to aid users in finding and exploring their personal history. We present two systems for lifelog retrieval: vitrivr and vitrivr-VR, which share a common retrieval model and backend for multi-modal multimedia retrieval. |
