scholarly journals Lights and Shadows: A Comprehensive Survey on Cooperative and Precoding Schemes to Overcome LOS Blockage and Interference in Indoor VLC

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 861
Author(s):  
Máximo Morales Céspedes ◽  
Borja Genovés Guzmán ◽  
Víctor P. Gil Jiménez
Keyword(s):  
High Rate ◽  
Visible Light Communications ◽  
Rf Systems ◽  
Indoor Wireless ◽  
Blocking Effects ◽  
Comprehensive Survey ◽  
Indoor Scenarios ◽  
Significant Attention ◽  
Open Issues ◽  
Comprehensive Study

Visible light communications (VLC) have received significant attention as a way of moving part of the saturated indoor wireless traffic to the wide and unregulated visible optical spectrum. Nowadays, VLC are considered as a suitable technology, for several applications such as high-rate data transmission, supporting internet of things communications or positioning. The signal processing originally derived from radio-frequency (RF) systems such as cooperative or precoding schemes can be applied to VLC. However, its implementation is not straightforward. Furthermore, unlike RF transmission, VLC present a predominant line-of-sight link, although a weak non-LoS component may appear due to the reflection of the light on walls, floor, ceiling and nearby objects. Blocking effects may compromise the performance of the aforementioned transmission schemes. There exist several surveys in the literature focused on VLC and its applications, but the management of the shadowing and interference in VLC requires a comprehensive study. To fill this gap, this work introduces the implementation of cooperative and precoding schemes to VLC, while remarking their benefits and drawbacks for overcoming the shadowing effects. After that, the combination of both cooperative and precoding schemes is analyzed as a way of providing resilient VLC networks. Finally, we propose several open issues that the cooperative and precoding schemes must face in order to provide satisfactory VLC performance in indoor scenarios.

scholarly journals A comprehensive survey on formal concept analysis, its research trends and applications

2016 ◽  
Vol 26 (2) ◽  
pp. 495-516 ◽  
Author(s):  
Prem Kumar Singh ◽  
Cherukuri Aswani Kumar ◽  
Abdullah Gani
Keyword(s):  
Incomplete Data ◽  
Granular Computing ◽  
Possibility Theory ◽  
Formal Concept ◽  
Research Papers ◽  
Emerging Trends ◽  
Comprehensive Survey ◽  
Interval Valued ◽  
Fuzzy Setting ◽  
Significant Attention

AbstractIn recent years, FCA has received significant attention from research communities of various fields. Further, the theory of FCA is being extended into different frontiers and augmented with other knowledge representation frameworks. In this backdrop, this paper aims to provide an understanding of the necessary mathematical background for each extension of FCA like FCA with granular computing, a fuzzy setting, interval-valued, possibility theory, triadic, factor concepts and handling incomplete data. Subsequently, the paper illustrates emerging trends for each extension with applications. To this end, we summarize more than 350 recent (published after 2011) research papers indexed in Google Scholar, IEEE Xplore, ScienceDirect, Scopus, SpringerLink, and a few authoritative fundamental papers.

scholarly journals Interferon Response in Hepatitis C Virus-Infected Hepatocytes: Issues to Consider in the Era of Direct-Acting Antivirals

2020 ◽  
Vol 21 (7) ◽  
pp. 2583 ◽  
Author(s):  
Pil Soo Sung ◽  
Eui-Cheol Shin
Keyword(s):  
Hepatitis C Virus ◽  
Hepatitis C ◽  
Rna Virus ◽  
High Rate ◽  
Interferon Response ◽  
Direct Acting Antivirals ◽  
Direct Acting Antiviral ◽  
Direct Acting ◽  
Global Population ◽  
Open Issues

When interferons (IFNs) bind to their receptors, they upregulate numerous IFN-stimulated genes (ISGs) with antiviral and immune regulatory activities. Hepatitis C virus (HCV) is a single-stranded, positive-sense RNA virus that affects over 71 million people in the global population. Hepatocytes infected with HCV produce types I and III IFNs. These endogenous IFNs upregulate a set of ISGs that negatively impact the outcome of pegylated IFN-α and ribavirin treatments, which were previously used to treat HCV. In addition, the IFNL4 genotype was the primary polymorphism responsible for a suboptimal treatment response to pegylated IFN-α and ribavirin. However, recently developed direct-acting antivirals have demonstrated a high rate of sustained virological response without pegylated IFN-α. Herein, we review recent studies on types I and III IFN responses in HCV-infected hepatocytes. In particular, we focused on open issues related to IFN responses in the direct-acting antiviral era.

scholarly journals Neural Machine Reading Comprehension: Methods and Trends

2019 ◽  
Vol 9 (18) ◽  
pp. 3698 ◽  
Author(s):  
Shanshan Liu ◽  
Xin Zhang ◽  
Sheng Zhang ◽  
Hui Wang ◽  
Weiming Zhang
Keyword(s):  
Reading Comprehension ◽  
Deep Learning ◽  
Research Field ◽  
The Past ◽  
Learning Techniques ◽  
Comprehensive Survey ◽  
Recent Trends ◽  
General Architecture ◽  
Machine Reading ◽  
Open Issues

Machine reading comprehension (MRC), which requires a machine to answer questions based on a given context, has attracted increasing attention with the incorporation of various deep-learning techniques over the past few years. Although research on MRC based on deep learning is flourishing, there remains a lack of a comprehensive survey summarizing existing approaches and recent trends, which motivated the work presented in this article. Specifically, we give a thorough review of this research field, covering different aspects including (1) typical MRC tasks: their definitions, differences, and representative datasets; (2) the general architecture of neural MRC: the main modules and prevalent approaches to each; and (3) new trends: some emerging areas in neural MRC as well as the corresponding challenges. Finally, considering what has been achieved so far, the survey also envisages what the future may hold by discussing the open issues left to be addressed.

A Survey of Network-on-Chip Security Attacks and Countermeasures

2021 ◽  
Vol 54 (5) ◽  
pp. 1-36
Author(s):  
Subodha Charles ◽  
Prabhat Mishra
Keyword(s):  
Focal Point ◽  
Network On Chip ◽  
Security Attacks ◽  
Security Vulnerabilities ◽  
Multicore System ◽  
Comprehensive Survey ◽  
On Chip ◽  
Manufacturing Technologies ◽  
Significant Attention ◽  
Prime Location

With the advances of chip manufacturing technologies, computer architects have been able to integrate an increasing number of processors and other heterogeneous components on the same chip. Network-on-Chip (NoC) is widely employed by multicore System-on-Chip (SoC) architectures to cater to their communication requirements. NoC has received significant attention from both attackers and defenders. The increased usage of NoC and its distributed nature across the chip has made it a focal point of potential security attacks. Due to its prime location in the SoC coupled with connectivity with various components, NoC can be effectively utilized to implement security countermeasures to protect the SoC from potential attacks. There is a wide variety of existing literature on NoC security attacks and countermeasures. In this article, we provide a comprehensive survey of security vulnerabilities in NoC-based SoC architectures and discuss relevant countermeasures.

scholarly journals A Perspective Roadmap for IoMT-Based Early Detection and Care of the Neural Disorder, Dementia

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Sapna Juneja ◽  
Gaurav Dhiman ◽  
Sandeep Kautish ◽  
Wattana Viriyasitavat ◽  
Kusum Yadav
Keyword(s):  
Early Detection ◽  
Dementia Patient ◽  
Daily Routine ◽  
Care Model ◽  
Computing Device ◽  
Normal Behavior ◽  
Comprehensive Survey ◽  
Neural Disorders ◽  
Vital Parameters ◽  
Open Issues

The Internet of Medical Things (IoMT) has emerged as one of the most important key applications of IoT. IoMT makes the diagnosis and care more convenient and reliable with proven results. The paper presents the technology, open issues, and challenges of IoMT-based systems. It explores the various types of sensors and smart equipment based on IoMT and used for diagnosis and patient care. A comprehensive survey of early detection and postdetection care of the neural disorder dementia is conducted. The paper also presents a postdiagnosis dementia care model named “Demencare.” This model incorporates eight sensors capable of tracking the daily routine of dementia patient. The patients can be monitored locally by an edge computing device kept at their premises. The medical experts may also monitor the patients’ status for any deviation from normal behavior. IoMT enables better postdiagnosis care for neural disorders, like dementia and Alzheimer’s. The patient’s behavior and vital parameters are always available despite the remote location of the patients. The data of the patients may be classified, and new insights may be obtained to tackle patients in a better manner.

scholarly journals Potential and Challenges on Amphibians and Reptiles Research in West Java

2019 ◽  
Vol 4 (2) ◽  
pp. 149-162
Author(s):  
Ganjar Cahyadi ◽  
Umilaela Arifin
Keyword(s):  
Environmental Changes ◽  
High Rate ◽  
Land Conversion ◽  
West Java ◽  
Amphibian Species ◽  
Reptile Species ◽  
Calotes Versicolor ◽  
Distribution Record ◽  
New Distribution ◽  
Comprehensive Study

 West Java Province has the largest population amongst others in Java, and therefore land conversion rate in the region is increasing. Approximately 40% of forest areas in West Java has been converted between 1990–2015. As a consequence, the number of bi­odiversity in the region is decreasing, including amphibians and rep­tiles. These groups play an important role in the food chain of an ecosystem, and are very sensitive to environmental changes. How­ever, comprehensive research on amphibian and reptile species in West Java is suboptimal. Visual Encounter Survey has performed in seven districts in West Java for one month and has recorded 26 amphibian species and 27 reptile species. These species were in­cluding Javan endemic species (for example: Fejervarya iskandari, Huia masonii, Limnonectes microdiscus, Megophrys montana, and Microhyla achatina), introduced species (Calotes versicolor), and species with a new distribution record (Leptophryne borbonica and Kalophrynus minusculus). In addition, cryptic species (Genus Lep­tophryne and Cyrtodactylus), which are interesting for further stud­ies, were observed. This study has demonstrated that the potential of a comprehensive study of amphibian and reptile species in West Java is great. Apart from this, conserving the biodiversity in the region also challenging due to the high rate in land conversion

scholarly journals Channel modelling for indoor visible light communications

2020 ◽  
Vol 378 (2169) ◽  
pp. 20190187 ◽  
Author(s):  
Farshad Miramirkhani ◽  
Murat Uysal
Keyword(s):  
Wireless Communication ◽  
Visible Light ◽  
Visible Light Communication ◽  
Visible Light Communications ◽  
Channel Models ◽  
Channel Modelling ◽  
Advantages And Disadvantages ◽  
Optical Propagation ◽  
Modelling Studies ◽  
Comprehensive Survey

Visible light communication (VLC) allows the dual use of light-emitting diodes (LEDs) for wireless communication purposes in addition to their primary purpose of illumination. As in any other communication system, realistic channel modelling is a key for VLC system design, analysis and testing. In this paper, we present a comprehensive survey of indoor VLC channel models. In order to set the background, we start with an overview of infrared (IR) channel modelling, which has received much attention in the past, and highlight the differences between visible and IR optical bands. In the light of these, we present a comparative discussion of existing VLC channel modelling studies and point out the relevant advantages and disadvantages. Then, we provide a detailed description of a site-specific channel modelling approach based on non-sequential ray tracing that precisely captures the optical propagation characteristics of a given indoor environment. We further present channel models for representative deployment scenarios developed through this approach that were adopted by the Institute of Electrical and Electronics Engineering (IEEE) as reference channel models. Finally, we consider mobile VLC scenarios and investigate the effect of receiver location and rotation for a mobile indoor user. This article is part of the theme issue ‘Optical wireless communication’.

scholarly journals Network Management and Monitoring Solutions for Vehicular Networks: A Survey

Electronics ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 853 ◽  
Author(s):  
João Dias ◽  
Joel Rodrigues ◽  
Vasco Soares ◽  
João Caldeira ◽  
Valery Korotaev ◽  
...  
Keyword(s):  
Vehicular Networks ◽  
Low Cost ◽  
Efficient Solutions ◽  
Transport Systems ◽  
Intelligent Transport Systems ◽  
Node Density ◽  
Intelligent Transport ◽  
Comprehensive Survey ◽  
Network Disruption ◽  
Open Issues

Vehicular networks are emerging as a promising technology that enables reliable and low-cost solutions for intelligent transport systems (ITSs), mainly due to their enormous potential to be considered for multiple purposes and scenarios. These networks are characterized by unique and challenging features such as packet fragmentation, low node density, short contact duration, and network disruption. These features may result in the absence of a path between the source and destination nodes, which is one of the most challenging issues faced by this type of network. To overcome some of these problems, it is necessary to provide vehicular networks with sophisticated tools or methodologies to implement monitoring and management operations. However, designing efficient solutions for this type of network is not an easy task due to its particular characteristics. This paper elaborates on a comprehensive survey focusing on promising proposals to deal with monitoring and management functionalities in vehicular networks. This work aims not only to present the state of the art on monitoring and management solutions but also to analyze their benefits and drawbacks, identify open issues, and provide guidelines for further contributions.

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