A Novel User Pairing Scheme for Functional Decode-and-Forward Multi-way Relay Network

In this paper, we consider a functional decode and forward (FDF) multi-way relay network (MWRN) where a common user facilitates each user in the network to obtain messages from all other users. We propose a novel user pairing scheme, which is based on the principle of selecting a common user with the best average channel gain. This allows the user with the best channel conditions to contribute to the overall system performance. Assuming lattice code based transmissions, we derive upper bounds on the average common rate and the average sum rate with the proposed pairing scheme. Considering M-ary quadrature amplitude modulation with square constellation as a special case of lattice code transmission, we derive asymptotic average symbol error rate (SER) of the MWRN. We show that in terms of the achievable rates, the proposed pairing scheme outperforms the existing pairing schemes under a wide range of channel scenarios. The proposed pairing scheme also has lower average SER compared to existing schemes. We show that overall, the MWRN performance with the proposed pairing scheme is more robust, compared to existing pairing schemes, especially under worst case channel conditions when majority of users have poor average channel gains.Comment: 30 pages, 6 figures, submitted for journal publicatio

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

Optimal user pairing to improve the sum rate of a pairwise AF multi-way relay network

In this letter, we propose a novel user pairing scheme for improving the average sum rate in an amplify and forward (AF) multi-way relay network (MWRN). We consider generalized lattice code based transmissions and derive upper bounds on the common rate and sum rate with the proposed scheme. We prove that pairing each user with the maximum average channel gain user is the optimal pairing scheme for an AF MWRN in terms of the average sum rate. Our results show that improving the overall channel conditions of the users results in greater benefits in terms of the average common rate and sum rate for the proposed pairing scheme, compared to the existing scheme

Multi-group multi-way relaying with multi-stage non-regenerative relay stations

This paper deals with a new decentralized observer-based controller design method for nonlinear discrete-time interconnected systems with nonlinear interconnections. Thanks to some algebraic transformations and the use of a new variant of Young\u27s inequality, an LMI-based approach is provided to compute the observer-based controller gain matrices. Furthermore, the congruence principle is used under a judicious and new manner leading to include additional slack variables and to cancel some bilinear matrix coupling. The effectiveness of proposed methodology is shown through an illustrative example

Impact of mixed pedagogy on engineering education

Contribution: This article explores the impact of the combination of various pedagogical approaches to deliver high-quality learning experiences for online-based engineering students. Though existing research extensively studied online education approaches, limited research has investigated how to bridge the gap between online cloud-based and campus-based students more effectively for obtaining hands-on engineering skills. Background: Given that engineers aim to solve real-world problems, engineering graduates need to obtain relevant experiences for employability. However, it is challenging to deliver such experiences in online education, which motivates innovative ways to integrate practical experiments in Web-based resources. Intended Outcomes: Practical and industry-relevant skills with flexibility in terms of time and pace of learning are intended to be achieved in the teaching framework which is expected to improve learning experiences for online students. Application Design: The adopted mixed pedagogical approach revolves around real-life problem-based learning delivered in the online mode using recorded experiments on energy-efficient design for three cohorts of the fourth-year engineering students, two of which are completely cloud-based students and the other one has a mix of on-campus and cloud-based students. Findings: The effectiveness of the adopted approach is measured through quantitative and qualitative evaluation tools. The evaluation demonstrated that cloud student engagement and motivation improved substantially by integrating explicit, analytical, as well as embodied learnings while enabling them to perform equally well as compared to the campus-based students

Optimum power allocation for sum rate improvement in AF multi-way relay networks

In this paper, we formulate and study the optimum power allocation problem in an amplify and forward (AF) multi-way relay network (MWRN). We derive closed-form analytical expressions for the optimum power allocation coefficients for the data power and the pilot power of the users and the relay to maximize the sum rate. We assume that only long term statistical channel state information (CSI) (i.e., channel variance) are available to each user and the relay. Our results show that to achieve the same sum rate, optimum power allocation requires 7-9 dB less transmit power compared to equal power allocation depending on users' channel conditions. In addition, we show that for optimum power allocation, the reduction in the sum rate due to channel estimation errors, becomes less compared to the case of equal power allocation