Energy harvesting over Rician fading channel: A performance analysis for half-duplex bidirectional sensor networks under hardware impairments

In this paper, a rigorous analysis of the performance of time-switching energy harvesting strategy that is applied for a half-duplex bidirectional wireless sensor network with intermediate relay over a Rician fading channel is presented to provide the exact-form expressions of the outage probability, achievable throughput and the symbol-error-rate (SER) of the system under the hardware impairment condition. Using the proposed probabilistic models for wireless channels between mobile nodes as well as for the hardware noises, we derive the outage probability of the system, and then the throughput and SER can be obtained as a result. Both exact analysis and asymptotic analysis at high signal-power-to-noise-ratio regime are provided. Monte Carlo simulation is also conducted to verify the analysis. This work confirms the effectiveness of energy harvesting applied in wireless sensor networks over a Rician fading channel, and can provide an insightful understanding about the effect of various parameters on the system performance.Web of Science186art. no. 1781

The cycle of commodification: migrant labour, welfare, and the market in global China and Vietnam

China and Vietnam have experienced waves of labour and welfare reform since both countries shifted to market socialism, pursuing a development model that depends on the labour of millions of rural–urban migrants in global factories. Their similar development trajectories are productive for theorizing the relationship between labour and welfare. This article conceptualises the two countries’ distinctive regime of migrant labour welfare as integral to a cycle of commodifcation that encompasses the overlapping processes of commodifcation, de-commodifcation and recommodifcation of labour. After decades of collectivized labour under state socialism, the cycle begins with the commodifcation of labour through market reforms that led to mass rural–urban migration and the rise of the global factory alongside the dismantling of the former socialist welfare system. It was then followed by decommodifcation attempts aimed at providing forms of social protection that ofset the labour precarity caused by decades of labour market liberalisation. Despite the emergence of new universal welfare programs, the market has increasingly intruded into social protection, especially through fnancialized products targeted at the labouring masses who must compensate for the failings of public welfare programs. As such, these welfare regimes are undergoing a process of re-commodifcation in which the protection of labour is re-embedded into the market as a commodity to be consumed by the migrant workers with their meagre wages. The “cycle of commodifcation” ofers an analytical framework to understand welfare regimes as a social and political feld that keeps evolving in response to the changing global valuation of labour

Two-way half duplex decode and forward relaying network with hardware impairment over Rician fading channel: system performance analysis

In this paper, the system performance analysis of a two-way decode and forward (DF) relaying network over the Rician fading environment under hardware impairment effect is proposed, analyzed and demonstrated. In this analysis, the analytical mathematical expressions of the achievable throughput, the outage probability, and ergodic capacity were proposed, analyzed and demonstrated. After that, the effect of various system parameters on the system performance is deeply studied with closed-form expressions for the system performance. Finally, the analytical results are also demonstrated by Monte-Carlo simulation in comparison with the closed-form expressions. The numerical results demonstrated and convinced the effect of the system parameters on the system performance of the two-way DF relaying network. The results show that the analytical mathematical and simulated results match for all possible parameter values.Web of Science242787

Welfare in Crisis: Labor and Social Protection in the Global South

Welfare expansion in the global South is partly in response to the social crises caused by neoliberal restructuring since the 1980s, with the 2008 global financial crisis escalating them, and the covid-19 pandemic further exposing the impact on the most precarious working populations. What are the new dynamics of labor struggles against these structural, industrial, and health crises under the expansion of social protection or the lack thereof? How do the state and non-state actors manage recurring and new capitalist crises by reconfiguring labor and social policies? The contributions in this special issue address these questions by engaging with workers’ lived experiences across the global South and post-communist states. They show that current labor and social policies fail the test under various crises. We argue that the neoliberalization of labor and welfare reconfigurations and the recurring crises of global capitalism have reproduced each other in these global South countries

EMaP: Explainable AI with Manifold-based Perturbations

In the last few years, many explanation methods based on the perturbations of input data have been introduced to improve our understanding of decisions made by black-box models. The goal of this work is to introduce a novel perturbation scheme so that more faithful and robust explanations can be obtained. Our study focuses on the impact of perturbing directions on the data topology. We show that perturbing along the orthogonal directions of the input manifold better preserves the data topology, both in the worst-case analysis of the discrete Gromov-Hausdorff distance and in the average-case analysis via persistent homology. From those results, we introduce EMaP algorithm, realizing the orthogonal perturbation scheme. Our experiments show that EMaP not only improves the explainers' performance but also helps them overcome a recently-developed attack against perturbation-based methods.Comment: 29 page

NeuCEPT: Locally Discover Neural Networks' Mechanism via Critical Neurons Identification with Precision Guarantee

Despite recent studies on understanding deep neural networks (DNNs), there exists numerous questions on how DNNs generate their predictions. Especially, given similar predictions on different input samples, are the underlying mechanisms generating those predictions the same? In this work, we propose NeuCEPT, a method to locally discover critical neurons that play a major role in the model's predictions and identify model's mechanisms in generating those predictions. We first formulate a critical neurons identification problem as maximizing a sequence of mutual-information objectives and provide a theoretical framework to efficiently solve for critical neurons while keeping the precision under control. NeuCEPT next heuristically learns different model's mechanisms in an unsupervised manner. Our experimental results show that neurons identified by NeuCEPT not only have strong influence on the model's predictions but also hold meaningful information about model's mechanisms.Comment: 6 main page

Influence of Post-translational Modifications on Hsp90 Activity and Function

The 90 kDa heat shock proteins constitute a family of highly conserved molecular chaperones that are essential in all eukaryotic cells. Assisted by an increasing number of cochaperones, Hsp90 forms highly dynamic complexes with numerous client proteins, many of which are signaling molecules controlling cell homeostasis, proliferation, differentiation, cell death, etc. Therefore, Hsp90 sits at one of the center positions in the protein quality control system and requires delicate regulation by the combination of different mechanisms. It is already well established in the field that the multiple conformations of Hsp90 are driven by association/dissociation with nucleotide and ATP hydrolysis together with binding and release of cochaperones as well as client proteins. On the other hand, post-translational modifications are becoming increasingly recognized as another layer of regulation that adds up to the complexity of the whole machinery. Hsp90 is a phospho-protein: approximately 40 sites have been detected in proteomics reports; nonetheless, individual phospho-sites seem to have different impact on the chaperone function of Hsp90. In the first part of this work, I aimed to analyze the global phosphorylation status of human cytosolic Hsp90 proteins in cancer versus non-cancer cells in a quantitative way and to examine whether the phosphorylation status relates to tumor selectivity characteristics of Hsp90 inhibitors.I found indications for novel phosphorylation sites that were not covered in proteomics studies so far. In the second part of this work, I focused on characterzing a novel serine phosphorylation that was first detected in the previous part and recently has been confirmed by other proteomics studies. Using S. cerevisiae as the model system in which both endogenous Hsp90 can be conditionally deleted, I was able to resolve the difference in chaperone function of human Hsp90 wild-type and phospho-mutants when being the sole source of Hsp90 proteins in yeast cells. My data suggested that the human Hsp90 wild-type was indeed phosphorylated in vivo and demonstrated strongly a correlation between phosphorylation and chaperone activity of Hsp90. My results supported a hypothesis in which a single modification on the molecular chaperone would be sufficient to provide a certain level of client specificity and modulate cellular responses upon environmental stimuli. To resolve further the mechanism of how this specific phosphorylation exerts its impact on Hsp90 function, I utilized in vitro minimal GR-activation system consisting of purified Hsp70, Hsp40, HOP, p23 and different Hsp90 wild-type or phospho-variant proteins. The profitable effect of the phospho-mimetic variant as compared with non-phosphorylatable variants was confirmed while that of wild-type protein was abolished due to the lack of post-translational modifications from E. coli expression and purification. I also examined the interaction of the Hsp90 wild-type protein and the phosphomutants with cochaperones by size-exclusive chromatography coupled with fluorescence detector using labeled proteins and isothermal titration calorimetry. The results showed that this phosphorylation impairs the binding of Hsp90 protein to both cochaperones Aha1 and Cdc37. Altogether, the data provided evidence for phosphorylation at this serine position on human Hsp90 that contributes to regulation of Hsp90 function via direct impacts on client and indirect effects via cochaperones involved in the chaperone cycle. As expected, the regulation of this molecular chaperone is the result of a delicate combination between several mechanisms rather than a single one, which would be more flexible to adapt to the variety of macro- and micro-environmental fluctuations that higher eukaryotes always must cope with

Spectral and Energy Efficiency Maximization for Content-Centric C-RANs with Edge Caching

This paper aims to maximize the spectral and energy efficiencies of a content-centric cloud radio access network (C-RAN), where users requesting the same contents are grouped together. Data are transferred from a central baseband unit to multiple remote radio heads (RRHs) equipped with local caches. The RRHs then send the received data to each group's user. Both multicast and unicast schemes are considered for data transmission. We formulate mixed-integer nonlinear problems in which user association, RRH activation, data rate allocation, and signal precoding are jointly designed. These challenging problems are subject to minimum data rate requirements, limited fronthaul capacity, and maximum RRH transmit power. Employing successive convex quadratic programming, we propose iterative algorithms with guaranteed convergence to Fritz John solutions. Numerical results confirm that the proposed joint designs markedly improve the spectral and energy efficiencies of the considered content-centric C-RAN compared to benchmark schemes. Importantly, they show that unicasting outperforms multicasting in terms of spectral efficiency in both cache and cache-less scenarios. In terms of energy efficiency, multicasting is the best choice for the system without cache whereas unicasting is best for the system with cache. Finally, edge caching is shown to improve both spectral and energy efficiencies.This work is supported in part by an ECRHDR scholarship from The University of Newcastle, in part by the Australian Research Council Discovery Project grants DP170100939 and DP160101537

Modular Probabilistic Models via Algebraic Effects

Probabilistic programming languages (PPLs) allow programmers to construct statistical models and then simulate data or perform inference over them. Many PPLs restrict models to a particular instance of simulation or inference, limiting their reusability. In other PPLs, models are not readily composable. Using Haskell as the host language, we present an embedded domain specific language based on algebraic effects, where probabilistic models are modular, first-class, and reusable for both simulation and inference. We also demonstrate how simulation and inference can be expressed naturally as composable program transformations using algebraic effect handlers