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The development of next-generation data storage devices relies on the efficient control of topological spin textures at ultrafast timescales with minimal energy consumption. Here, we theoretically investigate the switching of the magnetic skyrmion in ferrimagnetic GdFeCo utilizing the helicity-independent all-optical switching (HI-AOS) driven by femtosecond laser pulses. Our study demonstrates the switching of Néel skyrmion between the two degenerate skyrmion ground states having opposite polarity and chirality. A systematic study was done by varying the laser fluence, and we found that single-shot skyrmion switching is observed for a range of fluence values, where optically induced magnetization switching is observed. The present study proves that HI-AOS is a potential mechanism for switching magnetic skyrmion at ultrafast timescales. Our results offer significant insight into implementing optical writing skyrmion-based memory devices. [ABSTRACT FROM AUTHOR]

In this paper, we present the MU (multi-user) MIMO (multiple-input & multiple-output) system which is capable to serve the maximum number of users without additional bandwidth or power budget. MIMO systems maximize the channel capability as per the DPC scheme (Dirty Paper Coding). According to DPC, several antennas distributed over the base station are used for serving multiple users simultaneously. Nevertheless, DPC is a comprehensive search algorithm employing sequences of encoded user data for transmitting information to multiple users. Due to increased user density and subsequent transmit antennas in the MU-MIMO system, the exhaustive search (i.e. DPC) becomes cumbersome with the expanded search space domain. This search task would not be completed within a coherence time frame of the packet data communication system. The required objective is to consider this as a cost function for optimization to maximize the realizable sum-rate (throughput) of the MU-MIMO systems. This paper illuminates the joint antenna and user scheduling (JAAU) process with binary artificial bee colony (binary ABC) accomplishing nearly 98–99% of system throughput with the suggestively decreased figure in computation complexity and run time. Binary ABC is observed to have the global optimum value swiftly within the stipulated packet time frame of next-generation wireless data communications. Moreover, binary ABC achieves an appreciable system capacity for MU-MIMO systems as compared with DPC (which attains the maximum system throughput with the highest complexity). These findings are corroborated with exhaustive simulation results presented in this article. [ABSTRACT FROM AUTHOR]

Orbital arteriovenous malformations (AVM) are identified by abnormal high-flow connections between the veins and the arteries, which are often supplied by the branches of internal and external carotid arteries, also with a nidus of cellular stroma distributed between the vessels. Orbital arteriovenous malformations are rare among all congenital malformations. Pain, glaucoma, optic nerve ischemia and compression and retinal ischemia are some of the causes of enlarging orbital AVMs. Because of the rare nature of these lesions, they are usually misdiagnosed and treated improperly. For the diagnosis of such orbital AVMs, angiography becomes an essential tool. The primary method of diagnosing orbital AV malformations are non-invasive cross-sectional imaging and catheter angiography. Treatment for the same includes reducing the blood flow to the arteriovenous malformation (AVM) via preoperative embolization. And surgical resection. Complete excision is challenging because of the increased risk of involvement of the ophthalmic artery which can cause vision loss, preoperative embolization is difficult in some patients. An effective way of treating arteriovenous malformation is ethanol sclerotherapy. Diagnosing and managing Orbital AV malformations is important as these are rare and can cause permanent vision loss. [ABSTRACT FROM AUTHOR]