Mobile systems, whose components communicate and change their structure, now pervade the informational world and the wider world of which it is a part. The science of mobile systems is as yet immature, however. This book presents the pi-calculus, a theory of mobile systems. The pi-calculus provides a conceptual framework for understanding mobility, and mathematical tools for expressing systems and reasoning about their behaviours. The book serves both as a reference for the theory and as an extended demonstration of how to use pi-calculus to describe systems and analyse their properties. It covers the basic theory of pi-calculus, typed pi-calculi, higher-order processes, the relationship between pi-calculus and lambda-calculus, and applications of pi-calculus to object-oriented design and programming. The book is written at the graduate level, assuming no prior acquaintance with the subject, and is intended for computer scientists interested in mobile systems
We introduce the spi calculus, an extension of the pi calculus designed for the description and analysis of cryptographic protocols. We show how to use the spi calculus, particularly for studying authentication protocols. The pi calculus (without extension) suffices for some abstract protocols; the spi calculus enables us to consider cryptographic issues in more detail. We represent protocols as processes in the spi calculus and state their security properties in terms of coarse-grained notions of protocol equivalence.
Much recent theorizing about the utility of voting concludes that voting is an irrational act in that it usually costs more to vote than one can expect to get in return. 1 This conclusion is doubtless disconcerting ideologically to democrats; but ideological embarrassment is not our interest here. Rather we are concerned with an apparent paradox in the theory. The writers who constructed these analyses were engaged in an endeavor to explain political behavior with a calculus of rational choice; yet they were led by their argument to the conclusion that voting, the fundamental political act, is typically irrational. We find this conflict between purpose and conclusion bizarre but not nearly so bizarre as a non-explanatory theory: The function of theory is to explain behavior and it is certainly no explanation to assign a sizeable part of politics to the mysterious and inexplicable world of the irrational. 2 This essay is, therefore, an effort to reinterpret the voting calculus so that it can fit comfortably into a rationalistic theory of political behavior. We describe a calculus of voting from which one infers that it is reasonable for those who vote to do so and also that it is equally reasonable for those who do not vote not to do so. Furthermore we present empirical evidence that citizens actually behave as if they employed this calculus. 3
Fractional calculus is a collection of relatively little-known mathematical results concerning generalizations of differentiation and integration to noninteger orders. While these results have been accumulated over centuries in various branches of mathematics, they have until recently found little appreciation or application in physics and other mathematically oriented sciences. This situation is beginning to change, and there are now a growing number of research areas in physics which employ fractional calculus.This volume provides an introduction to fractional calculus for physicists, and co
Glossary Part I. Communicating Systems: 1. Introduction 2. Behaviour of automata 3. Sequential processes and bisimulation 4. Concurrent processes and reaction 5. Transitions and strong equivalence 6. Observation equivalence: theory 7. Observation equivalence: examples Part II. The pi-Calculus: 8. What is mobility? 9. The pi-calculus and reaction 10. Applications of the pi-calculus 11. Sorts, objects and functions 12. Commitments and strong bisimulation 13. Observation equivalence and examples 14. Discussion and related work Bibliography Index.
This monograph provides a comprehensive overview of the author's work on the fields of fractional calculus and waves in linear viscoelastic media, which includes his pioneering contributions on the applications of special functions of the Mittag-Leffler and Wright types. \nIt is intended to serve as a general introduction to the above-mentioned areas of mathematical modeling. The explanations in the book are detailed enough to capture the interest of the curious reader, and complete enough to provide the necessary background material needed to delve further into the subject and explore the research literature given in the huge general bibliography. \nThis book is likely to be of interest to applied scientists and engineers. See \nhttp://www.worldscibooks.com/mathematics/p614.html \nContents: \n•Essentials of Fractional Calculus \n•Essentials of Linear Viscoelasticity \n•Fractional Viscoelastic Media \n•Waves in Linear Viscoelastic Media: Dispersion and Dissipation \n•Waves in Linear Viscoelastic Media: Asymptotic Representations \n•Diffusion and Wave-Propagation via Fractional Calculus \n•The Eulerian Functions \n•The Bessel Functions \n•The Error Functions \n•The Exponential Integral Functions \n•The Mittag-Leffler Functions \n•The Wright Functions
Historical Survey The Modern Approach The Riemann-Liouville Fractional Integral The Riemann-Liouville Fractional Calculus Fractional Differential Equations Further Results Associated with Fractional Differential Equations The Weyl Fractional Calculus Some Historical Arguments.
Scientists have uncovered new evidence that fireworks can pollute both the air and water in ways that extend beyond the visible smoke。 The findings show that leftover debris, fine particles, and airborne chemicals may affect ecosystems and increase people's exposure to air pollution during major celebrations
Engineers at a deep underground research facility noticed something strange during major rainstorms: airflow underground sometimes reversed direction。 Using new sensors and mathematical modeling, they found that water rushing down a shaft was effectively pushing air through the tunnels like a giant piston。 The breakthrough explains a long-standing
Two newly confirmed "super-puff" planets are so diffuse that they are less dense than cotton candy, despite being about the size of Jupiter。 Their rare orbital relationship and enormous, lightweight atmospheres could provide valuable clues about how some of the strangest planets in the galaxy come to exist
Astronomers have released the largest gravitational wave catalog ever, revealing 161 new black hole collisions and pushing the total number of detections to 390。 Among the highlights are the clearest gravitational wave signal ever recorded, the most accurate location of a black hole merger, and growing evidence that some black holes are the product
Scientists have identified new clues that could help astronomers spot one of the most famous hypothetical alien megastructures: a Dyson sphere。 The study finds that red dwarfs and white dwarfs are the most promising stars to examine, since advanced civilizations could potentially build energy-harvesting swarms around them more easily。 These objects
Scientists have created a silicon chip that can write dozens of DNA sequences simultaneously using electricity and water-based enzymes, offering a cleaner alternative to conventional DNA manufacturing。 The breakthrough could eventually support portable DNA-writing devices and even massive DNA data storage, although new chemistry will be needed to s
Researchers have created an AI-based simulation that makes it much faster to model how neutron star mergers produce many of the universe's heaviest elements。 The new tool could improve predictions of these powerful explosions while helping scientists better connect observations in space with experiments on Earth
A major breakthrough in quantum technology has turned magnons, tiny magnetic waves once considered too short-lived for practical use, into promising carriers of quantum information。 Researchers extended their lifetime by nearly 100 times, reaching up to 18 microseconds, and discovered that the main limitation is not a law of physics but the purity
Reinforcement learning uses error information to adjust control algorithms
VW's plan calls for half as many models but didn't mention closures or job cuts