1,116 research outputs found
Energy harvesting based two-way full-duplex relaying network over a Rician fading environment: performance analysis
Full-duplex transmission is a promising technique to enhance the capacity of communication systems. In this paper, we propose and investigate the system performance of an energy harvesting based two-way full-duplex relaying network over a Rician fading environment. Firstly, we analyse and demonstrate the analytical expressions of the achievable throughput, outage probability, optimal time switching factor, and symbol error ratio of the proposed system. In the second step, the effect of various parameters of the system on its performance is presented and investigated. In the final step, the analytical results are also demonstrated by Monte Carlo simulation. The numerical results proved that the analytical results and the simulation results agreed with each other.Web of Science68112311
Multisource power splitting energy harvesting relaying network in half-duplex system over block Rayleigh fading channel: System performance analysis
Energy harvesting and information transferring simultaneously by radio frequency (RF) is considered as the novel solution for green-energy wireless communications. From that point of view, the system performance (SP) analysis of multisource power splitting (PS) energy harvesting (EH) relaying network (RN) over block Rayleigh-fading channels is presented and investigated. We investigate the system in both delay-tolerant transmission (DTT), and delay-limited transmission (DLT) modes and devices work in the half-duplex (HD) system. In this model system, the closed-form (CF) expressions for the outage probability (OP), system throughput (ST) in DLT mode and for ergodic capacity (EC) for DTT mode are analyzed and derived, respectively. Furthermore, CF expression for the symbol errors ratio (SER) is demonstrated. Then, the optimal PS factor is investigated. Finally, a Monte Carlo simulation is used for validating the analytical expressions concerning with all system parameters (SP).Web of Science81art. no. 6
Effect of the green-emitting CaF2:Ce3+,Tb3+ phosphor particles’ size on color rendering index and color quality scale of the in-cup packaging multichip white LEDs
In this paper, we investigate the effect of the green-emitting CaF2:Ce (3+), Tb (3+) phosphor particle's size on the color rendering index (CRI) and the color quality scale (CQS) of the in-cup packaging multichip white LEDs (MCW-LEDs). For this purpose, 7000K and 8500K in-cup packaging MCW-LEDs is simulated by the commercial software Light Tools. Moreover, scattering process in the phosphor layers is investigated by using Mie Theory with Mat Lab software. Finally, the research results show that the green-emitting CaF2: Ce (3+), Tb (3+) phosphor's size crucially influences on the CRI and CQS. From that point of view, CaF2: Ce (3+), Tb (3+) can be proposed as a potential practical direction for manufacturing the in-cup packaging phosphor WLEDs.Web of Science13235134
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
Efficient Human Vision Inspired Action Recognition using Adaptive Spatiotemporal Sampling
Adaptive sampling that exploits the spatiotemporal redundancy in videos is
critical for always-on action recognition on wearable devices with limited
computing and battery resources. The commonly used fixed sampling strategy is
not context-aware and may under-sample the visual content, and thus adversely
impacts both computation efficiency and accuracy. Inspired by the concepts of
foveal vision and pre-attentive processing from the human visual perception
mechanism, we introduce a novel adaptive spatiotemporal sampling scheme for
efficient action recognition. Our system pre-scans the global scene context at
low-resolution and decides to skip or request high-resolution features at
salient regions for further processing. We validate the system on EPIC-KITCHENS
and UCF-101 datasets for action recognition, and show that our proposed
approach can greatly speed up inference with a tolerable loss of accuracy
compared with those from state-of-the-art baselines. Source code is available
in https://github.com/knmac/adaptive_spatiotemporal
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
Multi-source in DF cooperative networks with the PSR protocol based full-duplex energy harvesting over a Rayleigh fading channel: performance analysis
Due to the tremendous energy consumption growth with ever-increasing connected devices, alternative wireless information and power transfer techniques are important not only for theoretical research but also for saving operational costs and for a sustainable growth of wireless communications. In this paper, we investigate the multi-source in decode-and-forward cooperative networks with the power splitting protocol based full-duplex energy harvesting relaying network over a Rayleigh fading channel. In this system model, the multi-source and the destination communicate with each other by both the direct link and an intermediate helping relay. First, we investigate source selection for the best system performance. Then, the closed-form expression of the outage probability and the symbol error ratio are derived. Finally, the Monte Carlo simulation is used for validating the analytical expressions in connection with all main possible system parameters. The research results show that the analytical and simulation results matched well with each other.Web of Science68327526
Regional Difference in Ethics Decision Making: A Study of IT Pre-professionals in China
Information and communications technology played a significant role in the recent economic growth of China, which now ranks as the second largest economy in the world. As a result, China faces many social and ethical challenges common to technology-advanced countries. Ethical reasoning and practices are often influenced by cultural expectations and regional norms. The purpose of this study is to investigate IT ethics decision making in different regions of China.An IT ethics survey was developed and administered in four regions in China with different degrees of westernization. The data were analyzed using standard cross tabulation and Chi-square test techniques. Preliminary results reveal observable differences among subjects from the four regions with respect to their decision choices, reasons for the choices, the scope of consideration, and the stage of their moral development. In particular, the subject group that was exposed to the strongest western influence, showed the highest degree of individualism in ethics decision making
UIT-ADrone: A Novel Drone Dataset for Traffic Anomaly Detection
Anomaly detection plays an increasingly important role in video surveillance and is one of the issues that have attracted various communities, such as computer vision, machine learning, and data mining in recent years. Moreover, drones equipped with cameras have quickly been deployed to a wide range of applications, starting from border security applications to street monitoring systems. However, there is a notable lack of adequate drone-based datasets available to detect unusual events in the urban traffic environment, especially in roundabouts, due to the density of interaction between road users and vehicles. To promote the development of anomalous event detection with drones in the complex traffic environment, we construct a novel large-scale drone dataset to detect anomalies involving realistic roundabouts in Vietnam, covering a large variety of anomalous events. Traffic at a total of three different roundabouts in Ho Chi Minh City was recorded with a camera-equipped drone. The resulting dataset contains 51 videos with total data traffic of nearly 6.5 h, captured across 206K frames with ten abnormal event types. Based on this dataset, we comprehensively evaluate the current state-of-the-art algorithms and what anomaly detection can do in drone-based video surveillance. This study presents a detailed description of the proposed UIT-ADrone dataset, along with information regarding data distribution, protocols for evaluation, baseline experimental results on our dataset, and other benchmark datasets, discussions, and paves the way for future work
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