![]() ![]() ![]() Rob Hutchinson returns in this issue with surprising psychological phenomena. Jacquelyn Keun has interviewed this teenager who is amazing the world and leading a unique environmental initiative. He then launched The Ocean Cleanup Project and has so far raised $2 million to make his idea reality. Boyan Slat was only 17 when he solved a problem that most said was insoluble, and had thus never been attempted: cleaning the floating plastic from the oceans. April Holloway introduces us to its cultural practices, complex funerary rites, belief systems, and more. Older than the empires of Mesopotamia and Egypt, Varna has the largest prehistoric necropolis in South-eastern Europe and, as far as we know, was the first to craft golden artifacts. Varna Culture is thought to be one of the most advanced civilizations of ancient Europe. Our articles, podcasts, and infographics. Older than the empires of Mesopotamia and Egypt, Varna has the largest prehistoric necropolis in South-eastern Europe and, as far as we know, was the first to craft. IEEE Spectrum is the flagship publication of the IEEE the world’s largest professional organization devoted to engineering and applied sciences. Unfortunately, this kind of model often fails to provide estimates that are accurate enough for a given application. To analyze more complex environments, numerous empirical models have been developed, such as the well-known P recommendations from the International Telecommunication Union–Radiocommunication Sector. However, due to insufficient computational capacity, this approach has been traditionally confined to problems involving relatively simple geometries, such as determining the electromagnetic field radiated by a dipole. Īrguably, spectrum cartography can be traced back to the application of Maxwell’s equations to characterize the propagation of radio waves across space. Radio maps are also useful for localization and tomography. Radio maps find a myriad of applications in wireless communications and networking, such as network planning, interference coordination and mitigation, power control, resource allocation, handoff management, multihop routing, dynamic spectrum access, and cognitive radio networking tasks see and and the references therein. ![]() A quick overview of the most representative types of radio maps is provided in Table 1. Spectrum cartography comprises a collection of techniques used to construct and maintain radio maps, which provide useful information on the radio-frequency (RF) landscape, such as the received signal power, interference power, power spectral density (PSD), electromagnetic absorption, and channel gain across a geographic area see, e.g.,, , and. To gain insight into this versatile toolkit, illustrative toy examples will also be presented. Starting from simple regression, the exposition gradually delves into more sophisticated algorithms, eventually touching upon state-of-the-art techniques. In this tutorial article, after presenting some representative applications of radio maps, the most prominent RME methods are discussed. Radio map estimation (RME) typically entails interpolative inference based on spatially distributed measurements. ![]() Radio maps characterize quantities of interest in radio communication environments, such as the received signal strength and channel attenuation, at every point of a geographical region. ![]()
0 Comments
Leave a Reply. |