Recently, megastable systems have grabbed many researchers’ interests in the area of nonlinear dynamics and chaotic systems. In this paper, the oscillatory terms’ coefficients of the simplest megastable oscillator are forced to blink in time. The forced system can generate an infinitive number of hidden attractors without changing parameters. The behavior of these hidden attractors can be chaotic, tori, and limit cycle. The attractors’ topology of the system seems unique and looks like picture frames. Besides, the existence of different coexisting (...) attractors with different kinds of behaviors reflects the system's high sensitivity. Using the sample entropy algorithm, the system’s complexity for different initial values is assessed. In addition, the circuit of the introduced forced system is designed, and the possibility of implicating the system with analog elements is investigated. (shrink)

This topic reflects the behavioral characteristics and the measurement of first class air travel worldwide. Airlines in the East are pushing the boundaries and investing heavily on their first class cabins and potentially competes for their premium passenger. On the other hand, first class market in the western part of the world has been disappearing for decades and rather replaced with improved business class cabins. The worldwide shock of most recent economic crisis had a downward impact on the premium air (...) travel and the post economic impacts were followed by some carriers cutting their first class capacity. The purpose of this research is to highlight whether first class make sense for the airlines to retain? This study is carried out with the research that some airlines have specifically targeted their routes that can fill expensive first class seats, and these were reflected by the strong presence of global business centers whereas others were diminishing due to less lucrative demand. This research will also show the complexity of airline hard product around the world and how they encounter to retain their premium passenger. (shrink)

Memristor-based oscillators are of recent interest, and hence, in this paper, we introduce a new Wien bridge oscillator with a fractional-order memristor. The novelty of the proposed oscillator is the multistability feature and the wide range of fractional orders for which the system shows chaos. We have investigated the various dynamical properties of the proposed oscillator and have presented them in detail. The oscillator is then realized using off-the-shelf components, and the results are compared with that of the numerical results. (...) A combination synchronization scheme is proposed which uses more than one driver systems to synchronize with one response system. Indeed, we use two different techniques where the first one consists of splitting the transmitted signals into two parts where each part is loaded in different drive systems, while the second one consists of dividing time into different intervals and loading the signals in different drive systems. Such techniques improve the antiattack capability of the systems when used for secure communication. (shrink)

The present study addresses the fluid transport behaviour of the flow of gold -copper /biomagnetic blood hybrid nanofluid in an inclined irregular stenosis artery as a consequence of varying viscosity and Lorentz force. The nonlinear flow equations are transformed into dimensionless form by using nonsimilar variables. The finite-difference technique is involved in computing the nonlinear transport dimensionless equations. The significant parameters like angle parameter, the Hartmann number, changing viscosity, constant heat source, the Reynolds number, and nanoparticle volume fraction on the (...) flow field are exhibited through figures. Present results disclose that the Lorentz force strongly lessens the hybrid nanofluid velocity. Elevating the Grashof number values enhances the rate of blood flow. Growing values of the angle parameter cause to reduce the resistance impedance on the wall. Hybrid nanoparticles have a superior wall shear stress than copper nanoparticles. The heat transfer rate is amplifying at the axial direction with the growing values of nanoparticles concentration. The applied Lorentz force significantly reduces the hybrid and unitary nanofluid flow rate in the axial direction. The hybrid nanoparticles expose a supreme rate of heat transfer than the copper nanoparticles in a blood base fluid. Compared to hybrid and copper nanofluid, the blood base fluid has a lower temperature. (shrink)

Hume's Reception in Early America: Expanded Edition brings together the original American responses to one of Britain's greatest men of letters, David Hume. Now available as a single volume paperback, this new edition includes updated further readings suggestions and dozens of additional primary sources gathered together in a completely new concluding section. From complete pamphlets and booklets, to poems, reviews, and letters, to extracts from newspapers, religious magazines and literary and political journals, this book's contents come from a wide variety (...) of sources published in colonial America and the early United States between 1758 and 1850. As well as classics by Thomas Jefferson, John Adams and Alexander Hamilton, it contains scores of unknown and hard-to-locate items, many of which have not been reprinted since their original publication. These responses are divided into four parts covering Hume's Essays; his Philosophical Writings; his History of England; and his Character and Death. Each of those parts has a separate introductory essay, and every selection is introduced by a short headnote that sets the piece in its historical context and provides bibliographical references. Packed with new insights into Hume and American thought and culture, Hume's Reception in Early America reveals the relevance and impact of Hume on American political, philosophical, historical, religious, and aesthetic debates. (shrink)

Biological evolution is a complex blend of ever changing structural stability, variability and emergence of new phe- notypes, niches, ecosystems. We wish to argue that the evo- lution of life marks the end of a physics world view of law entailed dynamics. Our considerations depend upon dis- cussing the variability of the very ”contexts of life”: the in- teractions between organisms, biological niches and ecosys- tems. These are ever changing, intrinsically indeterminate and even unprestatable: we do not know ahead of (...) time the ”niches” which constitute the boundary conditions on selec- tion. More generally, by the mathematical unprestatability of the ”phase space”, no laws of mo- tion can be formulated for evolution. We call this radical emergence, from life to life. The purpose of this paper is the integration of variation and diversity in a sound concep- tual frame and situate unpredictability at a novel theoretical level, that of the very phase space. Our argument will be carried on in close comparisons with physics and the mathematical constructions of phase spaces in that discipline. The role of symmetries as invariant preserving transformations will allow us to under- stand the nature of physical phase spaces and to stress the differences required for a sound biological theoretizing. In this frame, we discuss the novel notion of ”enablement”. Life lives in a web of enablement and radical emergence. This will restrict causal analyses to differential cases. Mutations or other causal differ- ences will allow us to stress that ”non conservation princi- ples” are at the core of evolution, in contrast to physical dynamics, largely based on conservation principles as sym- metries. Critical transitions, the main locus of symmetry changes in physics, will be discussed, and lead to ”extended criticality” as a conceptual frame for a better understanding of the living state of matter. (shrink)

This is a welcome reprint of a book that continues to grow in importance.

Editor James Fetzer presents an analytical and historical introduction and a comprehensive bibliography together with selections of many of Carl G. Hempel's most important studies to give students and scholars an ideal opportunity to appreciate the enduring contributions of one of the most influential philosophers of science of the 20th century.

Megastable chaotic systems are somehow the newest in the family of special chaotic systems. In this paper, a new megastable two-dimensional system is proposed. In this system, coexisting attractors are in some islands, interestingly covered by megalimit cycles. The introduced two-dimensional system has no defined equilibrium point. However, it seems that the origin plays the role of an unstable equilibrium point. Therefore, the attractors are determined as hidden attractors. Adding a forcing term to the system, we can obtain chaotic solutions (...) and coexisting strange attractors. Moreover, the effect of three different values of the forcing term’s amplitude is studied. The dynamical properties of the designed system are investigated using attractor plots, bifurcation diagrams, and Lyapunov Exponents diagram. Phase portraits of the novel megastable oscillator are presented by FPGA design. Xilinx system generator block diagrams of the proposed system and trigonometric functions are also presented. (shrink)

This entirely new work guides the reader through the most basic systems of modal propositional logic up to systems of modal predicate with identity, dealing with both technical developments and discussing philosophical applications.

Includes bibliographical references and index.

Research ethics committees (RECs) have played a crucial role in expediting the review of research protocols amidst the COVID‐19 pandemic. To improve their performance and identify areas of enhancement, a multicentric study was conducted in India by the Forum for Ethical Review Committees in the Asian and Western Pacific Region (FERCAP). The study aimed to evaluate the preparedness of Indian RECs during the COVID‐19 outbreak while conducting protocol reviews and comprehend the challenges they encountered. After obtaining ethics committee approval, a (...) cross‐sectional observational study was conducted using two validated questionnaires, one for REC member secretaries/chairpersons and another for REC members. The questionnaires consisted of 13 multiple‐choice questions, 10 yes or no questions, and 2 open‐ended questions each. The study was distributed to multiple RECs. A total of 109/200 participants, including 13 REC member secretaries, 12 chairpersons and 84 REC members from a total of 34 REC's, consented to participate in the study. During the COVID‐19 pandemic, 23/25 (92%) of the RECs conducted online meetings. The most common challenges faced by RECs included risk‐benefit analysis (12/25 RECs), review of informed consent (12/25 RECs), and protocols involving vulnerable populations (10/25 RECs). 65% of the REC members reported the need for ethics review training, and 66/84 REC members agreed or strongly agreed that RECs require training in COVID‐19 protocol review. Additionally, 62/84 REC members agreed or strongly agreed that central/joint RECs should review multicenter COVID‐19 protocols. RECs in India encountered difficulties while reviewing risk‐benefit analyses, informed consent documents (ICDs), and COVID‐19 protocols and they suggested providing training on these topics. (shrink)

An amplitude controllable hyperjerk system is constructed for chaos producing by introducing a nonlinear factor of memristor. In this case, the amplitude control is realized from a single coefficient in the memristor. The hyperjerk system has a line of equilibria and also shows extreme multistability indicated by the initial value-associated bifurcation diagram. FPGA-based circuit realization is also given for physical verification. Finally, the proposed memristive hyperjerk system is successfully predicted with artificial neural networks for AI based engineering applications.

By means of the averaging method of the first order, we introduce the maximum number of limit cycles which can be bifurcated from the periodic orbits of a Hamiltonian system. Besides, the perturbation has been used for a particular class of the polynomial differential systems.

Sensory feedback, which can be presented in different modalities - single and combined, aids task performance in human-robot interaction (HRI). However, combining feedback modalities does not always lead to optimal performance. Indeed, it is not known how feedback modalities affect operator performance under stress. Furthermore, there is limited information on how feedback affects neural processes differently for males and females and under stress. This is a critical gap in the literature, particularly in the domain of surgical robotics, where surgeons are (...) under challenging socio-technical environments that burden them physiologically. In the present study, we posited operator performance as the summation of task performance and neurophysiological cost of maintaining that performance. In a within-subject design, we used functional near-infrared spectroscopy (fNIRS) to assess cerebral activations of 12 participants who underwent a 3D manipulation task within a virtual environment with concurrent feedback (visual and visual + haptic) in the presence and absence of a cognitive stressor. Cognitive stress was induced with the serial-7 subtraction test. We found that while task performance was higher with visual than visual + haptic feedback, it degraded under stress. The two feedback modalities were found to be associated with varying neural activities and neural efficiencies, and these were stress- and gender-dependent. Our findings engender further investigation into effectiveness of feedback modalities on males and females under stressful conditions in HRI. (shrink)

A model for the ideal state includes discussions of the nature and application of justice, the role of the philosopher in society, the goals of education, and the effects of art upon character.

On one way of talking about a traditional metaethical topic, realists accept that some items appear on the list of what exists in the moral or more broadly normative domain of inquiry. They then divide over whether those items are like what science and experience suggest that all other items on the list of what exists across all domains are like – naturalistic and secular. Reductive naturalists answer this further question affirmatively. Why don’t nonnaturalists? I explore the answer that it’s (...) because normative entities are “just too different” in the sense that they are countably different things. However, I argue that this answer rests on the subtle presupposition that the normative domain doesn’t also contain uncountable entities of the sort that analytic metaphysicians call “stuff”. Taking intuitions of difference seriously points the way to a novel form of metaethical reductive naturalism. The key is to identify the stuff that matters. (shrink)

Each title in the "Key Issues" series aims to set the work in its historical context. In this collection of contemporary responses to "Leviathan", attention is focused on its critics who attacked Hobbes's moral, political and religious ideas in a series of pamphlets and short books.