RF system model for In-band full duplex communications

Abstract. In recent years by increasing the demands for communication services various technologies are examined in order to improve the throughput and spectrum efficiency of the wireless communication systems. For improving the performance a communication network, system deficiencies such as transmitter and receiver impairments need to be removed or compensated. One way to improve the network efficiency is to employ full duplex technology. Full duplex technology doubles the network capacity compared to the case when typical frequency division duplexing (FDD) or time division duplexing (TDD) are employed in a transceiver design. Although full duplex (FD) technology has enhanced the performance of the radio communication devices, the main challenge in full duplex communication is the leaking self-interference signal from the transmitter to the receiver. Different methods are employed to suppress the self-interference signal in digital and analog domains which are categorized as passive or active cancellations. These techniques are discussed in this thesis in order to understand from which point in the propagation path, the required signal for cancellation can be taken and how those techniques are employed in digital and analog domains. For having a good self-interference cancellation (SIC) both analog and digital cancellation techniques are needed since typical digital suppression method is low complex and somewhat limited. In this thesis, first we start with discussing about the full duplex technology and the reason why it has become popular in recent years and later full duplex deficiencies are examined. In the following chapters different cancellation methods are introduced and some results are provided in Chapter 5

Emotion Recognition from Electroencephalogram Signals based on Deep Neural Networks

Emotion recognition using deep learning methods through electroencephalogram (EEG) analysis has marked significant progress. Nevertheless, the complexities and time-intensive nature of EEG analysis present challenges. This study proposes an efficient EEG analysis method that foregoes feature extraction and sliding windows, instead employing one-dimensional Neural Networks for emotion classification. The analysis utilizes EEG signals from the Database for Emotion Analysis using Physiological Signals (DEAP) and focuses on thirteen EEG electrode positions closely associated with emotion changes. Three distinct Neural Models are explored for emotion classification: two Convolutional Neural Networks (CNN) and a combined approach using Convolutional Neural Networks and Long Short-Term Memory (CNN-LSTM). Additionally, two emotion labels are considered: four emotional ranges encompassing low arousal and low valence (LALV), low arousal and high valence (LAHV), high arousal and high valence (HAHV), and high arousal and low valence (HALV); and high valence (HV) and low valence (LV). Results demonstrate CNN_1 achieving an average accuracy of 97.7% for classifying four emotional ranges, CNN_2 with 97.1%, and CNN-LSTM reaching an impressive 99.5%. Notably, in classifying HV and LV labels, our methods attained remarkable accuracies of 100%, 98.8%, and 99.7% for CNN_1, CNN_2, and CNN-LSTM, respectively. The performance of our models surpasses that of previously reported studies, showcasing their potential as highly effective classifiers for emotion recognition using EEG signals

Ultra-Reliable Short Message Cooperative Relaying Protocols under Nakagami-m Fading

In the next few years, the development of wireless communication systems propel the world into a fully connected society where the Machine-type Communications (MTC) plays a substantial role as key enabler in the future cellular systems. MTC is categorized into mMTC and uMTC, where mMTC provides the connectivity to massive number of devices while uMTC is related to low latency and ultra-high reliability of the wireless communications. This paper studies uMTC with incremental relaying technique, where the source and relay collaborate to transfer the message to a destination. In this paper, we compare the performance of two distinct cooperative relaying protocols with the direct transmission under the finite blocklength (FB) regime. We define the overall outage probability in each relaying scenario, supposing Nakagami-m fading. We show that cooperative communication outperforms direct transmission under the FB regime. In addition, we examine the impact of fading severity and power allocation factor on the outage probability and the minimum delay required to meet the ultra-reliable communication requirements. Moreover, we provide the outage probability in closed form

Cooperative diversity mechanisms for critical machine-type communications

Abstract The need for the industrial Internet-of-Things (IIoT) and the challenges faced in the transition from traditional manufacturing to the next generation of factories is the motivation behind many research works that aim to meet the requirements of future factories. Ultra-reliable low latency communication (URLLC), known as critical machine-type communications (cMTC), is a key enabling force for future connectivity to bring about prominent opportunities in support of the IIoT. The goal of this thesis is to study different enablers for IIoT, discuss their associated challenges, research directions, and specifically focus on diversity mechanisms as a potential enabler for URLLC services in the factories of future. The first part of this thesis provides an overview of potential enablers to meet URLLC requirements. We discuss the corresponding merits and challenges of each technique, and their relevance to IIoT is highlighted. Thereafter, we survey cooperative diversity mechanisms to enable URLLC applications, and meet their corresponding requirements. The second part focuses on the performance analysis of URLLC via cooperative diversity techniques. Different performance metrics such as reliability, latency, and energy efficiency are studied, and the impact of different parameters such as coding rate, transmission power, pilot power/length, blocklength, and resource allocation under a hard deadline on system performance are examined. We aim to mathematically model and characterize the trade-offs between reliability and latency requirements. Finally, the last part of the thesis looks beyond the cooperative diversity technique to enable URLLC services for future connectivity.Tiivistelmä Tarve teolliseen esineiden Internettiin (IIoT) ja haasteet siirtymässä perinteisistä tuotantomenetelmistä seuraavan sukupolven tehtaisiin motivoivat useita tutkimustöitä löytämään ratkaisuja niiden vaatimuksiin. Erittäin luotettava pienen latenssin tiedonsiirto (URLLC), joka tunnetaan myös nimellä kriittinen konetyyppinen tietoliikenne (cMTC), on avainasemassa tulevaisuuden verkkoliittyvyydessä tarjoten huomiota herättäviä mahdollisuuksia IIoT-ratkaisuiksi. Tämän väitöskirjan tavoitteena on tutkia erilaisia IIoT:n mahdollistavia tekniikoita, käsitellä niihin liittyviä haasteita ja tutkimussuuntia sekä erityisesti keskittyä diversiteettimekanismeihin varteenotettavana URLLC-palvelujen mahdollistajana tulevaisuuden tehtaissa. Väitöstyön ensimmäinen osa sisältää yleiskatsauksen URLLC-vaatimukset täyttävistä tekniikkavaihtoehdoista. Kunkin tekniikan hyvät ja huonot puolet esitetään ja niiden IIoT-soveltuvuutta arvioidaan. Seuraavaksi tarkastellaan yhteistoiminnallisia diversiteettimenetelmiä mahdollistamaan URLLC-sovelluksia ja toteuttamaan niiden esittämiä vaatimusmäärittelyjä. Työn toinen osa keskittyy URLLC:n suorituskykyanalyysiin yhteistoiminnallisia diversiteettitekniikoita käytettäessä. Luotettavuus, latenssi ja energiatehokkuus ovat esimerkkejä monista tutkittavista suorituskykymittareista. Samoin eri parametrien, kuten koodaussuhde, lähetysteho, pilottisymbolin teho/pituus, lohkonpituus ja resurssiallokaatio, vaikutusta kovan määräajan järjestelmän suorituskykyyn tutkitaan. Työssä tähdätään matemaattiseen mallinnukseen luotettavuuden ja latenssivaatimusten välisen vuorovaikutuksen luonnehtimiseksi. Työn loppuosa tarkastelee yhteistoiminnallisten diversiteettitekniikoiden ulkopuolisia vaihtoehtoja URLLC-palveluihin tulevaisuuden verkkoliittyvyystoteutuksissa

Sun protection behaviors among children aged 6−18 years old, the role of socioeconomic factors: A cross‐sectional study

Abstract Background and Aims Evaluation of sun protection behavior and related factors in children aged between 6 and 18 years in Isfahan, Iran. Methods This cross‐sectional study was conducted at outpatient pediatric clinics affiliated with Isfahan University of Medical Sciences, Isfahan, Iran during the summer of 2021. A checklist was designed, and the interviewer used that to gather the required information including children's demographic characteristics, families' socioeconomic data, and sun‐protective behaviors in children. Results The mean ± standard deviation (SD) age of children was 10.54 ± 3.61. Among the study population, 63.7% of children were male. The most common skin phototypes were II and III (33.5% each). 83.8% of children used at least one method of sun protection (94.5% of girls, 77.6% of boys, p < 0.001). Wearing long‐sleeved clothes was the most frequent UV‐protection method (48%), while sunscreen application was the least prevalent method (28.1%). Sun protection behaviors were more frequent among urban children (86.7%, p = 0.009) and children with wealthy families (94%, p = 0.035). Sun protection methods were used by most of the children whose mothers applied sunscreen on a daily basis (90.2%, p = 0.002) and all of the children whose mothers held a master's degree or above (100%, p = 0.004). Conclusion Children's sun protection behavior is directly associated with demographic characteristics, families' socioeconomic level and maternal usage of sun protection measures. It is necessary to provide information and education about sun protection methods and the risks of excessive sun exposure to families and children, as well as facilitate their access to these

Cadmium accumulation in wastewater-irrigated vegetables: Exploring factors, thresholds, health implications, and transfer modeling

The Introduction of cadmium (Cd) into the soil-crop system through wastewater (WW) irrigation poses a significant challenge to environmental safety. However, the understanding of the relationship between Cd phytoavailability in WW-irrigated soil and its uptake characteristics in edible vegetables remains largely unknown. This study aims to analyze the influence of WW irrigation on the accumulation characteristics and health risks associated with Cd in the soil-vegetables system. Soil and corresponding vegetable samples were collected from 12 vegetable farms including cabbage, lettuce, green beans, and pepper were studied under wastewater (WW) and freshwater (FW) irrigation. WW irrigation led to a significant increase in soil Cd levels, with enrichment factor, and contamination factor values ranging from 2.9 to 3.1 and 2.7 to 3.3 times higher, respectively, compared to the control. Across the study farms, WW irrigation increased Cd concentrations in cabbage, green beans, lettuce, and pepper by 62–220%, 55–100%, 25–68%, and 29–80%, respectively, compared to FW-irrigated farms. The average hazard quotient (HQ) and carcinogenic risk (CR) scores for Cd in WW-irrigated vegetables indicated low risk (0.1 < HQ) and fell within the permissible range (1.00E-06 < CR < 1.00E-04) for children and adults. The soil DTPA-extractable Cd thresholds for WW-irrigated farms cultivating cabbage, lettuce, green beans, and pepper were 0.62, 0.72, 0.85, and 0.83 mg kg−1, respectively. The results provide insight into the management strategies along with developing sustainable production practices for common leafy vegetables in Cd-enriched soil resulting from WW irrigation

Management of internal root resorption in the maxillary central incisor with fractured root using Biodentine

Abstract Biodentine is desirable to successfully manage internal root resorption, and the MTA apical plug backfilled with thermoplasticized gutta‐percha is suggested for the tooth with external apical root resorption

Performance analysis of ultra-reliable short message decode and forward relaying protocols

Abstract Machine-type communication (MTC) is a rapidly growing technology which covers a broad range of automated applications and propels the world into a fully connected society. Two new use cases of MTC are massive MTC (mMTC) and ultra-reliable low latency communication (URLLC), where mMTC supports a large number of devices with high reliability and low rate connectivity while URLLC refers to excessively low outage probability under very stringent latency constraint. Herein, we examine the URLLC through three cooperative schemes, namely dual-hop decode and forward, selection combining, and maximum ratio combining, and compare to direct transmission under Rayleigh fading. We compare the performance of studied cooperative protocols under two distinct power constraints with respect to latency and energy efficiency. Moreover, we illustrate the impact of coding rate on the probability of successful transmission in ultra-reliable region in addition to the effect of power allocation on the outage probability. We also provide the performance analysis of cooperative schemes in terms of energy efficiency and latency requirements

In-band pilot overhead in ultra-reliable low latency decode and forward relaying

Abstract In URLLC the performance of short message communications highly depends on the training sequence length due to the stringent latency and reliability requirements. In this paper, we study the performance of cooperative and non-cooperative transmissions under imperfect channel estimation and Rayleigh fading for URLLC. We assume a peak power constraint on pilot symbols in addition to the average power constraint which is used for comparison purposes. We obtain the optimal training length as a function of blocklength and power constraint factor to meet the URLLC requirements. Moreover, the simulation results show the impact of pilot overhead on reliability, latency, and goodput of cooperative communications compared to point-to-point transmission

Ultra-reliable short message cooperative relaying protocols under Nakagami-m fading

Abstract In the next few years, the development of wireless communication systems propel the world into a fully connected society where the Machine-type Communications (MTC) plays a substantial role as key enabler in the future cellular systems. MTC is categorized into mMTC and uMTC, where mMTC provides the connectivity to massive number of devices while uMTC is related to low latency and ultra-high reliability of the wireless communications. This paper studies uMTC with incremental relaying technique, where the source and relay collaborate to transfer the message to a destination. In this paper, we compare the performance of two distinct cooperative relaying protocols with the direct transmission under the finite blocklength (FB) regime. We define the overall outage probability in each relaying scenario, supposing Nakagami-m fading. We show that cooperative communication outperforms direct transmission under the FB regime. In addition, we examine the impact of fading severity and power allocation factor on the outage probability and the minimum delay required to meet the ultra-reliable communication requirements. Moreover, we provide the outage probability in closed form