Cultivating Chaos: Entropy, Information, and the Making of the Dictionary of National Biography

The Dictionary of National Biography, published between 1885 and 1900, was one of Britain's biggest cyclopedia projects. The rampant expansion of the nation's archives, private collections, and museums produced an abundance of materials that frustrated the dictionary's editors, Leslie Stephen and Sidney Lee, especially because methodologies for making order of such materials were underdeveloped. Adding to their frustration was the sense of impending doom felt generally in Britain after the discovery of the second law of thermodynamics in 1859. Entropy put an end to the presiding belief in the infinite energy that fueled Britain's economic development and therefore challenged Victorian biography's premise that the capacity for self-development was boundless. Like the physicists of the era, these dictionary makers searched for ways to circumvent entropy's deadening force and reenergize their world. This project would not actually be achieved, however, until the twentieth century when Claude Shannon published his “Information Theory” in 1948. I argue that in an attempt to get out from under the chaos of information overload, the editors of the DNB invented new methods to organize information that anticipated Shannon's revolutionary theory and changed the way that we think, write, and work.

ViTool-BC: Visualization Tool Based on Cooja Simulator for WSN

Evaluation and monitoring of wireless sensor networks (WSN) and the parameters defining their operations and design, such as energy consumption, latency, and stability, is a complex task due to interaction with real devices. For greater control of these variables, the use of simulators arises as an alternative. Cooja is a WSN simulator/emulator which handles the devices’ controllers and multiple communication protocol implementations, such as RPL (RPL is one of the most used protocol in IoT). However, Cooja does not consider either the implementation of an energy model (it has infinite energy consumption) nor the visual behavior of the topology construction, although these aspects are crucial for effective network analysis and decision taking. This paper presents the design and the implementation of ViTool-BC, a software built on top of Cooja, which allows the creation of different energy estimation models and also to visualize in real time the behavior of WSN topology construction. In addition, ViTool-BC offers a heat map of energy consumption traces. Therefore, this tool helps researchers to monitor in real time the topology construction, node disconnection, and battery depletion, aspects to be considered in the analysis of the available routing protocols in Cooja.

Infinite Energy Problem of Fractional Circuit Elements: Overview and Perspectives

Fractional circuit elements become increasingly popular due to their versatility in various applications. However, the bottleneck in deploying these tools in practice is related to an open problem, i.e, infinite energy problem. On this topic, many valuable achievements have been made. Some scholars don’t dare to use fractional circuit elements because of the infinite energy problem while some scholars believe that there is no paradox compared with classical finite energy or even some scholars think that this problem has been successfully solved. However, there is still no consensus on this topic and confusion remains widespread. Consequently, a comprehensive review on infinite energy problem is needed imperatively. At this point, this paper reviews the consequences, root causes, and potential mitigation approaches through the modeling analysis and literature survey. This review starts with the fractional capacitors. Subsequently, other fractional circuit elements and fractional order operators/systems are considered. Finally, the main technical challenges as well as future researches on this topic are highlighted carefully.

Sharp Energy Self-Determination of Macroscopic Quantum Bodies in Pure States, as a Validation of the First Law of Thermodynamics

We argue that a very large class of quantum pure states of isolated macroscopic bodies have sharply peaked energy distributions, with their width relative to the average scaling between $\sim N^{-1}$ and $\sim N^{-1/2}$, with $N \gg 1$, the number of atoms conforming the body. Those states are dense superpositions of energy eigenstates within arbitrary finite or infinite energy intervals that decay sufficiently fast. The sharpness of the energy distribution implies that closed systems in those states are {\it microcanonical} in the sense that only energy eigenstates very near to the mean energy contribute to their thermodynamic evolution. Since thermodynamics accurately describes processes of macroscopic bodies and requires that closed systems have constant energy, our claim is that these pure states are typical of macroscopic systems. The main assumption beneath the energy sharpness is that the isolated body can reach thermal equilibrium if left unaltered. We argue that such a self-sharpness of the energy in macroscopic bodies indicates that the First Law of Thermodynamics is statistical in character.

Gravitational waves from fundamental axion dynamics

A totally asymptotically free QCD axion model, where all couplings flow to zero in the infinite energy limit, was recently formulated. A very interesting feature of this fundamental theory is the ability to predict some low-energy observables, like the masses of the extra fermions and scalars. Here we find and investigate a region of the parameter space where the Peccei-Quinn (PQ) symmetry is broken quantum mechanically through the Coleman-Weinberg mechanism. This results in an even more predictive framework: the axion sector features only two independent parameters (the PQ symmetry breaking scale and the QCD gauge coupling). In particular, we show that the PQ phase transition is strongly first order and can produce gravitational waves within the reach of future detectors. The predictivity of the model leads to a rigid dependence of the phase transition (like its duration and the nucleation temperature) and the gravitational wave spectrum on the PQ symmetry breaking scale and the QCD gauge coupling.

MEMS Vibrational Power Generator for Bridge Slab and Pier Health Monitoring

Micro energy harvesters (MEH) based on microelectromechanical systems (MEMS) are rapidly developing, providing a green and virtually infinite energy source. The electrostatic vibratory power generator outputs electric power when it vibrates, motivating us to apply it to vibrating civil infrastructures excited by ambient and daily traffic loadings. In this study, an innovative monitoring system utilizing MEH devices was proposed for detecting slab damage and pier scours for bridge structures. Its performance was numerically investigated with finite element models, where the damage in slabs was modeled with a reduced Young’s modulus and scours with fixed boundaries of inclined depth. It was shown that the powers generated at each MEH varied as the target structure’s modal frequency shifted and amplitude changed by damage or scour. A power generation index was proposed to identify slab damage and a reference-free method was introduced to detect uneven pier scours. Utilizing an electrostatic vibration-based MEH (MEMS vibrational power generator), this pioneering study showed that MEMS vibrational power generators can work as sensors for an infrastructure structural health monitoring system.

GLOBAL NEARLY-PLANE-SYMMETRIC SOLUTIONS TO THE MEMBRANE EQUATION

We prove that any simple planar travelling wave solution to the membrane equation in spatial dimension $d\geqslant 3$ with bounded spatial extent is globally nonlinearly stable under sufficiently small compactly supported perturbations, where the smallness depends on the size of the support of the perturbation as well as on the initial travelling wave profile. The main novelty of the argument is the lack of higher order peeling in our vector-field-based method. In particular, the higher order energies (in fact, all energies at order $2$ or higher) are allowed to grow polynomially (but in a controlled way) in time. This is in contrast with classical global stability arguments, where only the ‘top’ order energies used in the bootstrap argument exhibit growth, and reflects the fact that the background travelling wave solution has ‘infinite energy’ and the coefficients of the perturbation equation are not asymptotically Lorentz invariant. Nonetheless, we can prove that the perturbation converges to zero in $C^{2}$ by carefully analysing the nonlinear interactions and exposing a certain ‘vestigial’ null structure in the equations.