Factors Influencing Intention to use the COVID-19 Contact Tracing Application

This study investigated the effects of variables influencing the intention to use the COVID-19 tracker. Experiment results from 224 individuals revealed that performance expectations, trust, and privacy all have an impact on app usage intention. However, social impact, effort expectation, and facilitating conditions were not shown to be statistically significant. The conceptual model explained 60.07 percent of the amount of variation, suggesting that software developers, service providers, and policymakers should consider performance expectations, trust, and privacy as viable factors to encourage citizens to use the ap

A novel approach to security enhancement of chaotic DSSS systems

In this paper, we propose a novel approach to the enhancement of physical layer security for chaotic direct-sequence spread-spectrum (DSSS) communication systems. The main idea behind our proposal is to vary the symbol period according to the behavior of the chaotic spreading sequence. As a result, the symbol period and the spreading sequence vary chaotically at the same time. This simultaneous variation aims at protecting DSSS-based communication systems from the blind estimation attacks in the detection of the symbol period. Discrete-time models for spreading and despreading schemes are presented and analyzed. Multiple access performance of the proposed technique in the presence of additional white Gaussian noise (AWGN) is determined by computer simulations. The increase in security at the physical layer is also evaluated by numerical results. Obtained results show that our proposed technique can protect the system against attacks based on the detection of the symbol period, even if the intruder has full information on the used chaotic sequence.Peer ReviewedPostprint (author's final draft

Using Online Games in Teaching: A Bibliometric Analysis

This paper aims to study an overview of the using online games in teaching based on the Scopus data source from January 2016 to July 2023. The PRISMA model is used to guide the selection of articles. After selection and consideration, 19 scientific articles were included for analysis. The author analyzes information such as number of research articles, country, author, citations, keywords. The results showed that the number of research articles on the use of online games in teaching is increasing, in which the article “Using online game-based platforms to improve student performance and engagement in histology teaching" of the authors Felszeghy S. et al. (2019) most influential with a citation index of 81. Student, learning, online, games are keywords that often appear in the articles analyzed. Therefore, through systematic review research to help educational researchers, teachers identify important information about the use of online games in teaching so that they can guide future studies

The baseline characteristics and interim analyses of the high-risk sentinel cohort of the Vietnam Initiative on Zoonotic InfectiONS (VIZIONS)

The Vietnam Initiative for Zoonotic Infections (VIZIONS) includes community-based 'high-risk sentinel cohort' (HRSC) studies investigating individuals at risk of zoonotic infection due to occupational or residential exposure to animals. A total of 852 HRSC members were recruited between March 2013 and August 2014 from three provinces (Ha Noi, Dak Lak, and Dong Thap). The most numerous group (72.8%) corresponded to individuals living on farms, followed by slaughterers (16.3%) and animal health workers (8.5%). Nasal/pharyngeal and rectal swabs were collected from HRSC members at recruitment and after notifying illness. Exposure to exotic animals (including wild pigs, porcupine, monkey, civet, bamboo rat and bat) was highest for the Dak Lak cohort (53.7%), followed by Ha Noi (13.7%) and Dong Thap (4.0%). A total of 26.8% of individuals reported consumption of raw blood over the previous year; 33.6% slaughterers reported no use of protective equipment at work. Over 686 person-years of observation, 213 episodes of suspect infectious disease were notified, equivalent of 0.35 reports per person-year. Responsive samples were collected from animals in the farm cohort. There was noticeable time and space clustering of disease episodes suggesting that the VIZIONS set up is also suitable for the formal epidemiological investigation of disease outbreaks

Probabilistic Dynamic Framed Slotted ALOHA for RFID Tag Identification

Part of this paper was presented at IEEE Asia Pacific Wireless Communication Symposium 2011.In this paper, we study radio frequency identification tag identification problems using framed slotted ALOHA protocol. Each tag will be assumed to participate in the contention with a certain probability. Then, the frame size and the probability will be dynamically controlled by the reader in every reading round so that all the tags can be detected in a short period of time. Moreover, we propose a practical way of controlling the probability in terms of transmit power control, assuming Additive White Gaussian Noise channel or flat Rayleigh fading channel. Computer simulation results demonstrate the effectiveness of the proposed method

On the Design of NOMA-Enhanced Backscatter Communication Systems

Non-orthogonal multiple access (NOMA) and backscatter communication (BackCom) are two emerging technologies for low-power Internet of Things (IoT) applications. This paper addresses the performance of a monostatic BackCom system employing the hybrid time-division multiple-access (TDMA)/power-domain (PD) NOMA, where a reader simultaneously serves multiple backscatter nodes (BNs). While the conventional schemes are mainly for static NOMA-aided monostatic BackCom systems, we instead introduce the design framework for dynamic systems. Moreover, we also present novel schemes to further improve the performance of such conventional static systems. Specifically, as for the static NOMA-enhanced monostatic BackCom systems, we investigate two schemes: (i) a two-node pairing (TNP) scheme to increase the possibility of successfully decoding NOMA groups by not randomly pairing BNs for such groups as in conventional approach and (ii) an adaptive power reflection coefficient (APRC) scheme to enhance the system performance by adjusting BN’s power reflection coefficient based on the channel conditions. Regarding the dynamic NOMA-enhanced monostatic BackCom systems, two schemes, namely dynamic-sized pairing (DSP) and hybrid APRC/DSP, are proposed, in which the number of BNs in a NOMA group is not necessarily to be a fixed size. To illustrate the enhanced system using the proposed schemes, we analyze the performance of the BackCom system in terms of the number of successful backscatter nodes and the number of bits that can be successfully decoded by a controller/reader. The obtained results confirm the effectiveness of our proposed schemes compared to the conventional ones over the state-of-the-art

Maximum Likelihood Approach for RFID Tag Cardinality Estimation under Capture Effect and Detection Errors

Cardinality estimation schemes of Radio Frequency IDentification (RFID) tags using Framed Slotted ALOHA (FSA) based protocol are studied in this paper. Not as same as previous estimation schemes, we consider tag cardinality estimation problem under not only detection errors but also capture effect, where a tag's IDentity (ID) might not be detected even in a singleton slot, while it might be identified even in a collision slot due to the fading of wireless channels. Maximum Likelihood (ML) approach is utilized for the estimation of the detection error probability, the capture effect probability, and the tag cardinality. The performance of the proposed method is evaluated under different system parameters via computer simulations to show the method's effectiveness comparing to other conventional approaches