Multi-level Network Architecture Research Articles

A novel pansharpening model based on two parallel network architectures

ABSTRACT Pansharpening is an important technology for obtaining high-resolution multispectral (HRMS) images by fusing low-resolution multispectral (LRMS) images and high-resolution panchromatic (PAN) images. Although many pansharpening models have emerged by taking advantage of deep learning (DL) technology, there remains a pressing need to further assess pansharpening accuracy and stability when LRMS images with complex land-cover types. What’s more, these models often overlook the exploitation of PAN images’ inherent high-frequency information. To address these issues, we propose a pansharpening model combining multi-level and multi-scale network architectures. The multi-level network architecture is used to build spatial-spectral dependence on LRMS-PAN pairs, and strengthen the network’s feature capture capability by keeping the multi-level texture details. The multi-scale architecture is subsequently used to extract the spatial structure and deep texture of the PAN images at different scales. Downsampled experiments and real experiments in four standard datasets show that the proposed model achieves a state-of-the-art performance.

Problems of implementation of integrated satellite-ground NTN-network

The article is devoted to the discussion of challenges that arise during the rapid technological progress in satellite communication systems. The paper proposes an integrated satellite-ground system for systems of the 5G generation and above, discusses its architecture, methods and problems of its implementation, and scenarios for the use of the described system. Application areas requiring the depicted integrated architecture are described, and how this flexible multi-technology system can be used to provide global coverage and reliable access, provide transport communication via a satellite link, and data processing and content caching at the mobile edge. A multi-level network architecture with satellite and terrestrial elements will allow to create a telecommunications network with minimal delay, high deployment speed, guaranteed high quality of service and dynamic scalability, which can be controlled depending on the degree of system load and user needs in real time. Among the necessary technological solutions required for the successful implementation of the proposed system in the implementation of 5G are the following: millimeter-band communication, multi-access edge computing, network management and sharing, and spectrum sharing solutions.

Modeling higher order adaptivity of a network by multilevel network reification

AbstractIn network models for real-world domains, often network adaptation has to be addressed by incorporating certain network adaptation principles. In some cases, also higher order adaptation occurs: the adaptation principles themselves also change over time. To model such multilevel adaptation processes, it is useful to have some generic architecture. Such an architecture should describe and distinguish the dynamics within the network (base level), but also the dynamics of the network itself by certain adaptation principles (first-order adaptation level), and also the adaptation of these adaptation principles (second-order adaptation level), and may be still more levels of higher order adaptation. This paper introduces a multilevel network architecture for this, based on the notion network reification. Reification of a network occurs when a base network is extended by adding explicit states representing the characteristics of the structure of the base network. It will be shown how this construction can be used to explicitly represent network adaptation principles within a network. When the reified network is itself also reified, also second-order adaptation principles can be explicitly represented. The multilevel network reification construction introduced here is illustrated for an adaptive adaptation principle from social science for bonding based on homophily and one for metaplasticity in Cognitive Neuroscience.

Synergistically assembled MWCNT/graphene foam with highly efficient microwave absorption in both C and X bands

It is a great challenge to fabricate lightweight microwave absorption materials (MAMs) with strong electromagnetic wave attenuation over wide frequency range. In this work, ultralight multiwalled carbon nanotube (MWCNT)/graphene foams (CGFs) are prepared through a facile solvothermal method and their microwave absorption (MA) properties are fully investigated. The CGFs exhibit tunable complex permittivity and conductivity through regulating MWCNT loading and thermal reduction temperature. The addition of MWCNT remarkably enhances the MA intensity of CGFs in low frequency. A minimum reflection loss value of −39.5 dB and average absorption intensity exceeding 22.5 dB in both C (4–8 GHz) and X (8–12 GHz) bands are obtained. For the optimized CGF, the qualified bandwidth with reflection loss less than - 10 dB reaches up to 16 GHz, which covers the whole measured range of 2–18 GHz and shares the widest qualified bandwidth among open literature reports. Furthermore, a specific MA performance of 12243 dB cm2 g−1 is realized, which is one of the best results among various MAMs. The synergistic effect of MWCNT and graphene and thus obtained three dimensional high loss multilevel network architecture are thought to be the primary causes for the excellent MA performance of CGFs.

New Tree-Structured Optical Codes for Incoherent Optical-CDMA Applications

Optical codes with large cardinality and tree structure of multiple levels of subsets of codewords for adjustable performance and cardinality have recently been studied. These codes support contemporary applications, such as a scalable, multihop, multilevel network architecture with rapid code-switching/dropping and multicode-keying encryption for improving physical-layer confidentiality in optical code-division multiple-access systems and networks. In this paper, to further enlarge such code collection, two new families of optical codes are constructed from the rich families of cyclic maximal-distance-separable (MDS) codes. The code performances are algebraically analyzed using both the distance and weight distributions of the MDS codes and validated with computer simulation.