A Talk-Listen-Ack Beaconing Strategy for Neighbor Discovery Protocols in Wireless Sensor Networks

Neighbor discovery is a fundamental function for sensor networking. Sensor nodes discover each other by sending and receiving beacons. Although many time-slotted neighbor discovery protocols (NDPs) have been proposed, the theoretical discovery latency is measured by the number of time slots rather than the unit of time. Generally, the actual discovery latency of a NDP is proportional to its theoretical discovery latency and slot length, and inversely proportional to the discovery probability. Therefore, it is desired to increase discovery probability while reducing slot length. This task, however, is challenging because the slot length and the discovery probability are two conflicting factors, and they mainly depend on the beaconing strategy used. In this paper, we propose a new beaconing strategy, called talk-listen-ack beaconing (TLA). We analyze the discovery probability of TLA by using a fine-grained slot model. Further, we also analyze the discovery probability of TLA that uses random backoff mechanism to avoid persistent collisions. Simulation and experimental results show that, compared with the 2-Beacon approach that has been widely used in time-slotted NDPs, TLA can achieve a high discovery probability even in a short time slot. TLA is a generic beaconing strategy that can be applied to different slotted NDPs to reduce their discovery latency.

The Discovery of Black Light

|This article is the beginning of a reexpresson, and partial revision, of my book Black Light. The questions that I discuss in this article are listed in the below list of sections. In Sections 7, 8, 27, and 28, I discuss my discovery of black light. |The theoretical discovery of black light (that is, the thought experimental discovery of black light): The black spatial field in, for example, a “dark” room is actually, I argue, black light; and it is emitted from everything in the spatial field of the room (that is, the relatively empty space, and all objects). If, hypothetically, the black light in the above room was removed, we, when we would look into the spatial field of the room, would be blind, despite that we have the capacity to see. |The observational discovery of black light: There is no such thing as a “colorless” visual field for observers: A “colorless” visual field would be a visual field of blindness for observers, despite that they have vision, and that their eyes would be open. The black visual field is not, as is commonly stated, “the absence of photons”, “the absence of visible light”, and the, as such, absence of color: If it were, then it would be “colorless” (that is, not black), and, as such, a visual field of blindness for observers. |The experimental confirmation of black light via neurophysics: In Section 28, I demonstrate that particular EEG experimentation that was done on test-subjects in various conditions provides evidence or proof that the black of the black visual field that strikes our retinas is black light.

Consequences of Brian Josephson’s Theoretical Discovery

Theoretical discovery of Josephson effects has beneficial consequences for science and economy, and in the future promises more benefits for public health. The strongest impact thus far has the use of Josephson devices and circuits in many areas of science and in geophysical prospecting for minerals. I highlight a few examples of present and future benefits.

Revisiting Our Quantum World

Of course, now we know that quantum mechanics has been a fundamental structure of our world since our universe came into being. However, it has been only a century since the experimental and theoretical discovery of quantum mechanics and its extensions into many implications and applications. In particular, there are implications across many disciplines that most likely will affect education, health, security, etc. Examples are given of the need for starting education as early as possible in schools, the use of nano-robots to deliver drugs targeted to specific molecular sites, to developing new cryptographic systems to safeguard our privacy.

How Poverty Became a Violation of Human Rights: The Production of a New Political Subject, France and Belgium, 1964–88

The institutionalization of guaranteed minimum income systems in France and Belgium, carried out through the modernization of assistance schemes (Minimex in 1974, RMI in 1988), has generally been presented as the political outcome of the “rediscovery” of “hidden” poverty in the “affluent” societies of the mid-1960s. This article argues that a vision of this shift in terms of a “discovery,” however, suffers from significant limitations. To understand the historical pedigree of the reforms, this article will examine how the issue of “poverty” as such, was not simply “discovered” as a neglected social ill, but rather, “produced” to allow for new techniques of social intervention. The theoretical discovery of the “poverty” issue then, was marked by the slow constitution of a new political subject known as the “poor,” whose categorization and conceptualization would stand in stark opposition to the postwar welfare state notions of social justice and equality.

Theoretical discovery of Dirac half metal in experimentally synthesized two dimensional metal semiquinoid frameworks

Dirac cone in metal-semiquinoid frameworks.