Z-Differential Equations Mazandarani, Mehran; Zhao, Yi
IEEE transactions on fuzzy systems,
2020-March, 2020-3-00, Letnik:
28, Številka:
3
Journal Article
Recenzirano
This paper is devoted to make a framework for studying a class of uncertain differential equations called Z-differential equations. In order to achieve the purpose, we first introduce four basic ...operations on Z + -numbers based on semigranular function. Then, the limit and continuity concepts of a Z-number-valued function are given, under a definition of a metric on the space of Z + -numbers. Moreover, the concepts of Z-differentiability, Z-integral, and Z-Laplace transform of a Z-number-valued function are introduced. In addition, by giving some theories proved in this paper, a basis for calculus-Z-calculus-is established. We further give theories based on which existence and uniqueness of Zdifferential equations are investigated. A conceptual unity between Z-differential equations and Z + -numbers is also shown. The conceptual unity demonstrates that a Z-differential equation may be expressed as a bimodal differential equation combining a fuzzy differential equation (FDE) and a random differential equation. Moreover, the concept of a bimodal cut called (s, μ)-cut is introduced and its relation to other new concepts such as acceptable time and acceptable information area is explained. Using an example, the application of Z-differential equations in medicine is clarified. It is demonstrated that Z-differential equations outperform FDEs in making a decision under uncertainty.
In this work, the possibility of using different generations of <inline-formula><tex-math notation="LaTeX">\beta</tex-math></inline-formula>-Ga 2 O 3 as an ultra-wide-bandgap power semiconductor ...device for high power converter applications is explored. The competitiveness of <inline-formula><tex-math notation="LaTeX">\beta</tex-math></inline-formula>-Ga 2 O 3 for power converters in still not well quantified, for which the major determining factors are the on-state resistance, <inline-formula><tex-math notation="LaTeX">R_{\text{ON}}</tex-math></inline-formula>, reverse blocking voltage, <inline-formula><tex-math notation="LaTeX">V_{\text{BR}}</tex-math></inline-formula>, and the thermal resistance, <inline-formula><tex-math notation="LaTeX">R_{\text{th}}</tex-math></inline-formula>. We have used the best reported device specifications from literature, both in terms of reports of experimental measurements and potential demonstrated by computer-aided designs, to study power converter performance for different device generations. Modular multilevel converter-based voltage source converters are identified as a topology with significant potential to exploit these device characteristics. The performance of MVDC & HVDC converters based on this topology have been analysed, focusing on system level power losses and case temperature rise at the device level. Comparisons of these <inline-formula><tex-math notation="LaTeX">\beta</tex-math></inline-formula>-Ga 2 O 3 devices are made against contemporary SiC-FET and Si-IGBTs. The results have indicated that although the early <inline-formula><tex-math notation="LaTeX">\beta</tex-math></inline-formula>-Ga 2 O 3 devices are not competitive to incumbent Si-IGBT and SiC-FET modules, the latest experimental measurements on NiO<inline-formula><tex-math notation="LaTeX">_\mathrm{X}</tex-math></inline-formula>/<inline-formula><tex-math notation="LaTeX">\beta</tex-math></inline-formula>-Ga 2 O 3 and <inline-formula><tex-math notation="LaTeX">\beta</tex-math></inline-formula>-Ga 2 O 3 /diamond significantly surpass the performance of incumbent modules. Furthermore, parameters derived from semiconductor-level simulations indicate that the <inline-formula><tex-math notation="LaTeX">\beta</tex-math></inline-formula>-Ga 2 O 3 /diamond in superjunction structures delivers even superior performance in these power converters.
Subsampling or subdata selection is a useful approach in large-scale statistical learning. Most existing studies focus on model-based subsampling methods which significantly depend on the model ...assumption. In this article, we consider the model-free subsampling strategy for generating subdata from the original full data. In order to measure the goodness of representation of a subdata with respect to the original data, we propose a criterion, generalized empirical <inline-formula><tex-math notation="LaTeX">F</tex-math> <mml:math><mml:mi>F</mml:mi></mml:math><inline-graphic xlink:href="zhang-ieq1-3297167.gif"/> </inline-formula>-discrepancy (GEFD), and study its theoretical properties in connection with the classical generalized <inline-formula><tex-math notation="LaTeX">\ell _{2}</tex-math> <mml:math><mml:msub><mml:mi>ℓ</mml:mi><mml:mn>2</mml:mn></mml:msub></mml:math><inline-graphic xlink:href="zhang-ieq2-3297167.gif"/> </inline-formula>-discrepancy in the theory of uniform designs. These properties allow us to develop a kind of low-GEFD data-driven subsampling method based on the existing uniform designs. By simulation examples and a real case study, we show that the proposed subsampling method is superior to the random sampling method. Moreover, our method keeps robust under diverse model specifications while other popular model-based subsampling methods are under-performing. In practice, such a model-free property is more appealing than the model-based subsampling methods, where the latter may have poor performance when the model is misspecified, as demonstrated in our simulation studies. In addition, our method is orders of magnitude faster than other model-free subsampling methods, which makes it more applicable for subsampling of Big Data.
A new class of twin Sudoku tables (TSTs) is presented. These tables can be divided into both <inline-formula><tex-math notation="LaTeX">s \times d</tex-math></inline-formula> and ...<inline-formula><tex-math notation="LaTeX">d \times s</tex-math></inline-formula> subtables. They are constructed using the cyclotomic cosets of <inline-formula><tex-math notation="LaTeX">Z_n</tex-math></inline-formula> via two distinct vectors of cyclotomic coset elements and their Kronecker product. We prove that it is possible to generate <inline-formula><tex-math notation="LaTeX">m</tex-math></inline-formula> TSTs that are strongly mutually distinct (SMD), i.e., for every <inline-formula><tex-math notation="LaTeX">0\leq i, j \leq m-1</tex-math></inline-formula>, the <inline-formula><tex-math notation="LaTeX">(i,j)</tex-math></inline-formula>th entry of the tables contains different symbols. We also provide a method to construct <inline-formula><tex-math notation="LaTeX">m</tex-math></inline-formula> different TSTs that can be converted into twin solid Sudoku tables (TSSTs) as a perfect set of SMD TSSTs in order to make triplet solid Sudoku cubes (TSSCs). These TSSCs are symmetric cubes so that a cut from any of the six faces is a TSST. As a result, new twin Sudoku puzzles (TSPs) and SMDTSPs are obtained that can be used to design new types of Sudoku games.
The objective of this research is to describe and investigate a novel class of separation axioms and discuss some of their fundamental characteristics using a nano weakly generalized closed set. In ...nano topological space, Nwg-closed graph and strongly Nwg-closed graph functions are introduced and explored. We also analyse some of the characterizations of closed graph functions with the separation axioms via a nano weakly generalized closed set.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
An eye-opening look at the invisible workers who protect us from seeing humanity's worst on today's commercial internetSocial media on the internet can be a nightmarish place. A primary shield ...against hateful language, violent videos, and online cruelty uploaded by users is not an algorithm. It is people. Mostly invisible by design, more than 100,000 commercial content moderators evaluate posts on mainstream social media platforms: enforcing internal policies, training artificial intelligence systems, and actively screening and removing offensive material-sometimes thousands of items per day. Sarah T. Roberts, an award-winning social media scholar, offers the first extensive ethnographic study of the commercial content moderation industry. Based on interviews with workers from Silicon Valley to the Philippines, at boutique firms and at major social media companies, she contextualizes this hidden industry and examines the emotional toll it takes on its workers. This revealing investigation of the people "behind the screen" offers insights into not only the reality of our commercial internet but the future of globalized labor in the digital age.
The study of the q -analogue of the classical results of geometric function theory is currently of great interest to scholars. In this article, we define generalized classes of close-to-convex ...functions and quasi-convex functions with the help of the q -difference operator. Moreover, by using the q -analogues of a certain family of linear operators, the classes K q ,bs h , K˜ q ,sb h , Q q ,bs h , and Q˜ q ,sb h are introduced. Several interesting inclusion relationships between these newly defined classes are discussed, and the invariance of these classes under the q -Bernadi integral operator was examined. Furthermore, some special cases and useful consequences of these investigations were taken into consideration.
The Extended \eta- } Composite Fading Distribution Silva, Hugerles S.; Badarneh, Osamah S.; Queiroz, Wamberto J. L.
IEEE transactions on vehicular technology,
2022-Sept., 2022-9-00, Letnik:
71, Številka:
9
Journal Article
Recenzirano
In this paper, the extended <inline-formula><tex-math notation="LaTeX">\eta</tex-math></inline-formula>-<inline-formula><tex-math notation="LaTeX">{\mathcal F}</tex-math></inline-formula> composite ...fading distribution is proposed. This new distribution is simple, characterized in terms of physical parameters, able to model environments where the multipath fading coexists with shadowing and takes into account the clustering imbalance between the in-phase and quadrature components. For the aforementioned distribution, new expressions are derived for the probability density function (PDF); cumulative distribution function, higher-order moments and moment generating function of the instantaneous signal-to-noise ratio; joint envelope-phase PDF and amount of fading. Subsequently, expressions are deduced for the outage probability, average symbol error probability and average channel capacity. An asymptotic analysis is also provided. Several curves are presented and the theoretical results are corroborated by Monte-Carlo simulations. Furthermore, an empirical validation is demonstrated in an underwater acoustic scenario, in which a better fit between the theoretical PDF and the empirical data is perceived for the extended <inline-formula><tex-math notation="LaTeX">\eta</tex-math></inline-formula>-<inline-formula><tex-math notation="LaTeX">{\mathcal F}</tex-math></inline-formula> model, when compared to the extended <inline-formula><tex-math notation="LaTeX">\eta</tex-math></inline-formula>-<inline-formula><tex-math notation="LaTeX">\mu</tex-math></inline-formula> and <inline-formula><tex-math notation="LaTeX">\kappa</tex-math></inline-formula>-<inline-formula><tex-math notation="LaTeX">\mu</tex-math></inline-formula> shadowed distributions.
This paper proposes a novel algorithm which made it feasible to predict the harmonic fault signatures under dynamic eccentricity in Permanent-Magnet synchronous machines with concentrated ...non-overlapping winding for any slot-pole combination. In the literature, only the appearance of the fractional harmonic components related with the pole number has been proposed but there are no studies to predict which exact components will rise in each topology. Initially, a mathematical equation is derived for the machine EMF under dynamic eccentricity based on the air gap permeance model. Later on, the terms of this equation are inserted in a Fault Signature Block Binary Array in which the position of each cell expresses a specific harmonic frequency component. After substitution of the machines parameters, the array results with zero and nonzero terms. The positions of the nonzero terms express the frequency components excited by this particular fault. 3-D FEA and experimental results of a Permanent-Magnet Axial-Flux Machine are used to validate the proposed algorithm.
Mobile edge computing ( MEC ) is leveraged to reduce the latency for the computation-intensive and latency-critical tasks offloaded from wireless devices and Internet of Things Devices ( IoTDs ). ...Unmanned aerial vehicles ( UAV s) have attracted much attention from both academia and industry attributed to high mobility, high flexibility, and high maneuverability of UAVs. In this article, a novel UAV-assisted MEC architecture is proposed to provision services to IoTDs, where a UAV provides both communication and computing services or works as a relay node. We then formulate the joint c omputation offloading, spectrum resource a llocation, computation resource allocation, and UAV p lacement ( Joint-CAP ) problem in the UAV-MEC network to minimize the operation cost of provisioning IoTDs. Since the Joint-CAP problem is a mixed integer non-linear programming problem and NP-hard, we decompose it into two sub-problems and solve the sub-problems sequentially. Then, we propose a <inline-formula><tex-math notation="LaTeX">(1+\epsilon)</tex-math></inline-formula>-approximation algorithm, named AA-CAP, to solve the Joint-CAP problem, and the performance of the AA-CAP algorithm is demonstrated to be superior to the baseline algorithms via simulations.
