This paper considers the secure transmission in a cell-free massive MIMO system with imperfect radio frequency (RF) chains and low-resolution analog-to-digital converters (ADCs) digital-to-analog (DACs) at both access points (APs) legitimate users, where an active eavesdropper attempts to wiretap confidential data. The Gaussian RF impairment model (GRFIM) additive quantization noise (AQNM) are ...

Digital-to-analog converters (DACs) with bandwidths larger than 70 GHz and sampling rates in excess of 170 GS/s will soon be required ultra-high speed communication applications such as coherent optical transceivers operating at symbol 140 GBd beyond. Frequency interleaving has been proposed a way to break the bandwidth bottleneck applications. Splitting input signal into multiple frequency ban...

Double-atom catalysts (DACs) have emerged as an enhanced platform of single-atom catalyst for promoting electrocatalytic CO2 reduction reaction (CO2RR). Herein, we present a density-functional theory study on CO2RR performance seven C2N-supported homo- and heteronuclear DACs, denoted M2@C2N. Our results demonstrate that there exists substantial synergistic effect dual-metal-atom N2M2N2 active s...

On 1996 March 14È15 we conducted a campaign with the Hubble Space Telescope GHRS to observe the Si IV jj1394, 1403 lines of the B0.5e star c Cas at high temporal and spectral resolution. As a part of this D22 hr campaign, the Rossi X-Ray T iming Explorer (RXT E) was also used to monitor this starÏs copious and variable X-ray emission. In this fourth paper of a series we present an analysis of t...

Ants are fascinating creatures that demonstrate the ability to find food and bring it back to their nest. Their ability as a colony, to find paths to food sources has inspired the development of algorithms known as Ant Colony Systems (ACS). The principle of cooperation forms the backbone of such algorithms, commonly used to find solutions to problems such as the Traveling Salesman Problem (TSP)...

Recently considerable interest in behavior-based robots has been generated by industrial, space and defence related activities. Such independent robots are envisioned to perform tasks where safety or economic factors prevent direct human control and communication difficulties prevent easy remote control. Although many successes have been reported using behavior-based robots with prespecified sk...

BACKGROUND The injection of botulinum toxin type A for cosmetic proposes is a popular procedure, although the interpretation of its effectiveness still poses a challenge. In fact, although the methods that evaluate the efficacy of the treatment are validated and reliable, they are usually based on subjective scales, while an objective and quantitative scale is still needed. OBJECTIVES I propo...

A personal portal, which is an entrance wherein each user can acquire the information that s/he is interested in on a network, is often used as an alternative means of communication. However, there are a number of problems with the existing personal portals. For example, because the Web page as a personal portal is generated by the program located on the specific Web server which is managed by ...