A virtual MIMO dual-hop architecture based on hybrid spatial modulation

International audienceIn this paper, we propose a novel Virtual Multiple-Input-Multiple-Output (VMIMO) architecture based on the concept of Spatial Modulation (SM). Using a dual-hop and Decode-and-Forward protocol, we form a distributed system, called Dual-Hop Hybrid SM (DH-HSM). DH-HSM conveys information from a Source Node (SN) to a Destination Node (DN) via multiple Relay Nodes (RNs). The spatial position of the RNs is exploited for transferring information in addition to, or even without, a conventional symbol. In order to increase the performance of our architecture, while keeping the complexity of the RNs and DN low, we employ linear precoding using Channel State Information (CSI) at the SN. In this way, we form a Receive-Spatial Modulation (R-SM) pattern from the SN to the RNs, which is able to employ a centralized coordinated or a distributed uncoordinated detection algorithm at the RNs. In addition, we focus on the SN and propose two regularized linear precoding methods that employ realistic Imperfect Channel State Information at the Transmitter. The power of each precoder is analyzed theoretically. Using the Bit Error Rate (BER) metric, we evaluate our architecture against the following benchmark systems: 1) single relay; 2) best relay selection; 3) distributed Space Time Block Coding (STBC) VMIMO scheme; and 4) the direct communication link. We show that DH-HSM is able to achieve significant Signal-to-Noise Ratio (SNR) gains, which can be as high as 10.5 dB for a very large scale system setup. In order to verify our simulation results, we provide an analytical framework for the evaluation of the Average Bit Error Probability (ABEP)

Examining Environmental Hazards in Rental Homes and Habitability Laws in Clark County, Nevada

It is well established that home conditions are linked to the health outcomes of occupants. There are over 880,000 housing units in Clark County, Nevada; nearly half of those are renter-occupied units (ROUs). Currently, there is limited research on the characteristics of environmental hazards found in Clark County ROUs and the strength of habitability statutes created to protect tenants from substandard housing. Understanding how renters in Clark County are affected by environmental hazards in ROUs and the processes by which landlords and tenants resolve grievances related to those hazards would benefit public health. It would enhance the ability to quickly identify which ROUs are at most risk for hazards and allow public health professionals to better plan and implement strategies intended to mitigate or prevent negative health outcomes created by those hazards. This study examined data from the Clark County Landlord and Tenant Hotline Study to answer the following questions: (1) Is there a relationship between the age of ROUs and the types of environmental hazards found in them? (2) Is there is a statistically significant difference in the proportions of hazards remediated by tenants who received a site inspection from the SNHD or sought legal advice in addition to sending a complaint letter to their landlord? (3) Do the age of an ROU, the number of complaints made by each tenant, or complaint category influence the likelihood of remediation? An ANOVA revealed that the average age of ROU’s was statistically significantly different between hazard categories, F(4, 445)= 5.11, p = 0.002. A Bonferroni post hoc analysis revealed mean differences werestatistically significant between essential services (� ̅= 35.27, SD = 16.59) and mold (� ̅= 27.64, SD = 12.77; p \u3c 0.05) and essential services and other (�̅ = 23.25, SD = 11.62; p \u3c 0.05). A chi-square test of homogeneity suggested that there was no statistically significant difference in the proportions of hazards remediated by tenants who pursued different levels of intervention, X2 = 1.11, p = 0.292. A binary logistic regression revealed that for each 1-year increase in ROU age, the likelihood of remediation was decreased by 2.5%. For tenants with one complaint, the odds of remediation were 1.75 times (95% CI =1.06 - 2.89) that of tenants with multiple complaints. For complaints categorized as essential, the odds of remediation were 4.15 times (95% CI =1.36 -12.7) that of complaints categorized as non-essential. The results suggest that the mean age ofROU’s with essential service complaints is higher than ROU’s with complaints categorized as mold or other. Furthermore, a tenant’s probability of getting hazards remediated was not significantly increased if they received a site inspection or sought legal advice in addition to sending their landlord a letter. The study suggests that tenants were less likely to get their hazard remediated by their landlords if they had multiple complaints, lived in an older home, or had a non-essential complaint. The results of this study can be used to enhance our abilities to quickly identify which ROUs in Clark County are most at risk for hazards and identify the factors that influence the likelihood of remediation

Design guidelines for spatial modulation

A new class of low-complexity, yet energyefficient Multiple-Input Multiple-Output (MIMO) transmission techniques, namely the family of Spatial Modulation (SM) aided MIMOs (SM-MIMO) has emerged. These systems are capable of exploiting the spatial dimensions (i.e. the antenna indices) as an additional dimension invoked for transmitting information, apart from the traditional Amplitude and Phase Modulation (APM). SM is capable of efficiently operating in diverse MIMO configurations in the context of future communication systems. It constitutes a promising transmission candidate for large-scale MIMO design and for the indoor optical wireless communication whilst relying on a single-Radio Frequency (RF) chain. Moreover, SM may also be viewed as an entirely new hybrid modulation scheme, which is still in its infancy. This paper aims for providing a general survey of the SM design framework as well as of its intrinsic limits. In particular, we focus our attention on the associated transceiver design, on spatial constellation optimization, on link adaptation techniques, on distributed/ cooperative protocol design issues, and on their meritorious variants

Systematic review and network meta-analysis on the efficacy of evolocumab and other therapies for the management of lipid levels in hyperlipidemia

Background: The proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibitors evolocumab and alirocumab substantially reduce low‐density lipoprotein cholesterol (LDL‐C) when added to statin therapy in patients who need additional LDL‐C reduction. Methods and Results: We conducted a systematic review and network meta‐analysis of randomized trials of lipid‐lowering therapies from database inception through August 2016 (45 058 records retrieved). We found 69 trials of lipid‐lowering therapies that enrolled patients requiring further LDL‐C reduction while on maximally tolerated medium‐ or high‐intensity statin, of which 15 could be relevant for inclusion in LDL‐C reduction networks with evolocumab, alirocumab, ezetimibe, and placebo as treatment arms. PCSK9 inhibitors significantly reduced LDL‐C by 54% to 74% versus placebo and 26% to 46% versus ezetimibe. There were significant treatment differences for evolocumab 140 mg every 2 weeks at the mean of weeks 10 and 12 versus placebo (−74.1%; 95% credible interval −79.81% to −68.58%), alirocumab 75 mg (−20.03%; 95% credible interval −27.32% to −12.96%), and alirocumab 150 mg (−13.63%; 95% credible interval −22.43% to −5.33%) at ≥12 weeks. Treatment differences were similar in direction and magnitude for PCSK9 inhibitor monthly dosing. Adverse events were similar between PCSK9 inhibitors and control. Rates of adverse events were similar between PCSK9 inhibitors versus placebo or ezetimibe. Conclusions: PCSK9 inhibitors added to medium‐ to high‐intensity statin therapy significantly reduce LDL‐C in patients requiring further LDL‐C reduction. The network meta‐analysis showed a significant treatment difference in LDL‐C reduction for evolocumab versus alirocumab

A survey on Bluetooth multi-hop networks

Bluetooth was firstly announced in 1998. Originally designed as cable replacement connecting devices in a point-to-point fashion its high penetration arouses interest in its ad-hoc networking potential. This ad-hoc networking potential of Bluetooth is advertised for years - but until recently no actual products were available and less than a handful of real Bluetooth multi-hop network deployments were reported. The turnaround was triggered by the release of the Bluetooth Low Energy Mesh Profile which is unquestionable a great achievement but not well suited for all use cases of multi-hop networks. This paper surveys the tremendous work done on Bluetooth multi-hop networks during the last 20 years. All aspects are discussed with demands for a real world Bluetooth multi-hop operation in mind. Relationships and side effects of different topics for a real world implementation are explained. This unique focus distinguishes this survey from existing ones. Furthermore, to the best of the authors’ knowledge this is the first survey consolidating the work on Bluetooth multi-hop networks for classic Bluetooth technology as well as for Bluetooth Low Energy. Another individual characteristic of this survey is a synopsis of real world Bluetooth multi-hop network deployment efforts. In fact, there are only four reports of a successful establishment of a Bluetooth multi-hop network with more than 30 nodes and only one of them was integrated in a real world application - namely a photovoltaic power plant. © 2019 The Author

Twitter in Mexican Politics: Messages to People or Candidates?

Twitter has reached Mexican politics in the presidential election. Despite the fact candidates have a twitter account to send messages; we propose the question how they use it to communicate with citizens? This exploratory research provides evidence that Mexican presidential candidates are only sending messages for politicians and not for citizens. We collected and analyzed 618 tweets from the three most important political parties: PRI, PAN and PRD, from November 2011 to February 2012. Using a five category framework, we found that most candidates sent thank and regret messages, but very few messages to their militancy and citizens. We found that the lack of information about this technological tool has disabled Mexican politicians to take advantage of this tool. Finally we hope this research contributes to analyze the impact of social media in Mexican Politics in a more systematic way

International financial reporting standards and financial reporting quality among Nigerian listed companies

This research investigates International Financial Reporting Standards (IFRS) and financial reporting quality among Nigerian listed companies. The research focused on qualitative characteristics of financial reporting (value relevance and timeliness). The study determined the financial reporting quality of 77 sample companies listed on Nigerian stock exchange. The study was limited to one year financial statement, which used UUM-Data stream in collecting the relevant data. The regression result of value relevance of financial reports reveals that there is a positive and significant relationship between stock price with book value of equity and net income after the adoption of IFRS. Similarly, timeliness of financial information regression results also revealed that return on assets and returns on equity are positive and significantly associated with stock returns after IFRS adoption in Nigeria. The findings implied that the financial reporting of Nigerian listed companies were value relevant and timelier after the adoption of IFRS. The significant positive relationship between accounting measures on stock price and stock returns shows that investors’ can predict future market value of individual securities, as the efficient market theory posits that securities prices disclose a significant amount of information from many different sources in the securities market and important current financial information of companies. Investor receives considerable information simply by knowing the price information on time which found more value relevan

Validity and Reliability of Physiological Data in Applied Settings Measured by Wearable Technology: A Rapid Systematic Review

The purpose of this review was to evaluate the current state of the literature and to identify the types of study designs, wearable devices, statistical tests, and exercise modes used in validation and reliability studies conducted in applied settings/outdoor environments. This was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines. We identified nine articles that fit our inclusion criteria, eight of which tested for validity and one tested for reliability. The studies tested 28 different devices with exercise modalities of running, walking, cycling, and hiking. While there were no universally common analytical techniques used to measure accuracy or validity, correlative measures were used in 88% of studies, mean absolute percentage error (MAPE) in 75%, and Bland–Altman plots in 63%. Intra-class correlation was used to determine reliability. There were not any universally common thresholds to determine validity, however, of the studies that used MAPE and correlation, there were only five devices that had a MAPE of... (see full abstract in article)

Centrifugal Pump Fault Detection with Convolutional Neural Network Transfer Learning

The centrifugal pump is the workhorse of many industrial and domestic applications, such as water supply, wastewater treatment and heating. While modern pumps are reliable, their unexpected failures may jeopardise safety or lead to significant financial losses. Consequently, there is a strong demand for early fault diagnosis, detection and predictive monitoring systems. Most prior work on machine-learning based centrifugal pump fault detection is based on either synthetic data, simulation or data from test rigs in controlled laboratory conditions. In this research paper, we attempt to detect centrifugal pump faults using data collected from real operational pumps deployed in various places in collaboration with a specialist pump engineering company. The detection is done by binary classifying visual features of DQ/Concordia patterns with residual networks. Besides using a real dataset, the paper employs transfer learning from image detection domain to systematically solve a real-life problem in engineering domain. By feeding DQ image data to popular and high-performance residual network (e.g ResNet-34), the proposed approach achieved up to 85.51% of classification accuracy.<br/