Max-Min Fairness Based on Cooperative-NOMA Clustering for Ultra-Reliable and Low-Latency Communications

In this paper, the performance of a cooperative relaying technique in a non-orthogonal multiple access (NOMA) system, briefly named cooperative NOMA (C-NOMA), is considered in short packet communications with finite blocklength (FBL) codes. We examine the performance of a decode-and-forward (DF) relaying along with selection combining (SC) and maximum ratio combining (MRC) strategies at the receiver. Our goal is user clustering based on C-NOMA to maximize fair throughput in a DL-NOMA scenario. In each cluster, the user with a stronger channel (strong user) acts as a relay for the other one (weak user), and optimal power and blocklength are allocated to achieve max-min throughput.Comment: 11 pages, 6 figures, This paper has been submitted for IEEE systems journa

Drag coefficient of a rising bubble in a shear-thinning fluid using the power-law scheme coupled with a Cahn-Hilliard equation with a variable mobility: A lattice Boltzmann study and comparison with experiment

This study aims to investigate the behavior of multicomponent fluid flows consisting of Newtonian and non-Newtonian components, especially terminal velocity of a rising bubble in a power-law fluid. A recent lattice Boltzmann (LB) model is extended using power-law scheme to be able to simulate both Newtonian and non-Newtonian fluid flows at high density and viscosity ratios. Also, a variable mobility is introduced in this study to minimize the unphysical error around small bubbles in the domain. A three-component fluid flow system is examined using a constant and variable mobility. It is shown that each component has more stability using variable mobility while constant mobility causes interface dissipation, leading to mass loss gradually. In addition, two test cases including power-law fluid flows driven between two parallel plates are conducted to show the accuracy and capability of the model. To find a grid-independent computational domain, a grid independency test is carried out to show that a 200*400 domain size is suitable for our computations. Then, terminal velocity of a rising bubble is compared to an existing correlation in the literature, indicating that the results are in good agreement with existing study so that average relative error in six different cases is 5.66 %. Also, the simulated examples show good conformity to experimental results over a range of the Reynolds and Eotvos numbers

Development of an Easy-to-Use Tool for the Assessment of Emergency Department Physical Design

Physical design of the emergency department (ED) has an important effect on its role and function. To date, no guidelines have been introduced to set the standards for the construction of EDs in Iran. In this study we aim to devise an easy-to-use tool based on the available literature and expert opinion for the quick and effective assessment of EDs in regards to their physical design. For this purpose, based on current literature on emergency design, a comprehensive checklist was developed.  Then, this checklist was analyzed by a panel consisting of heads of three major EDs and contradicting items were decided. Overall 178 crude items were derived from available literature. The Items were categorized in to three major domains of Physical space, Equipment, and Accessibility. The final checklist approved by the panel consisted of 163 items categorized into six domains. Each item was phrased as a “Yes or No” question for ease of analysis, meaning that the criterion is either met or not.

Cooperative NOMA-Based User Pairing for URLLC : A Max-Min Fairness Approach

In this paper, cooperative non-orthogonal multiple access (C-NOMA) is considered in short packet communications with finite blocklength (FBL) codes. The performance of a decode-and-forward (DF) relaying along with selection combining (SC) and maximum ratio combining (MRC) strategies at the receiver side is examined. We explore joint user pairing and resource allocation to maximize fair throughput in a downlink (DL) scenario. In each pair, the user with a stronger channel (strong user) acts as a relay for the other one (weak user), and optimal power and blocklength are allocated to achieve max-min throughput. To this end, first, only one pair is considered, and optimal resource allocation is explored. Also, a suboptimal algorithm is suggested, which converges to a near-optimal solution. Finally, the problem is extended to a general scenario, and a suboptimal C-NOMA-based user pairing is proposed. Numerical results show that the proposed C-NOMA scheme in both SC and MRC strategies significantly improves the users’ fair throughput compared to the NOMA and OMA. It is also investigated that the proposed pairing scheme based on C-NOMA outperforms the Hybrid NOMA/OMA scheme from the average throughput perspective, while the fairness index degrades slightl

Estimation bayésienne de signaux discrets à dépendances locales

The aim of this thesis is to study the problem of data detection in wireless communication system, for both case of perfect and imperfect channel state information at the receiver. As well known, the complexity of MLSE being exponential in the channel memory and in the symbol alphabet cardinality is quickly unmanageable and forces to resort to sub-optimal approaches. Therefore, first we propose a new iterative equalizer when the channel is unknown at the transmitter and perfectly known at the receiver. This receiver is based on continuation approach, and exploits the idea of approaching an original optimization cost function by a sequence of more tractable functions and thus reduce the receiver's computational complexity. Second, in order to data detection under linear dynamic channel, when the channel is unknown at the receiver, the receiver must be able to perform joint equalization and channel estimation. In this way, we formulate a combined state-space model representation of the communication system. By this representation, we can use the Kalman filter as the best estimator for the channel parameters. The aim in this section is to motivate rigorously the introduction of the Kalman filter in the estimation of Markov sequences through Gaussian dynamical channels. By this we interpret and make clearer the underlying approximations in the heuristic approaches. Finally, if we consider more general approach for non linear dynamic channel, we can not use the Kalman filter as the best estimator. Here, we use switching state-space model (SSSM) as non linear state-space model. This model combines the hidden Markov model (HMM) and linear state-space model (LSSM). In order to channel estimation and data detection, the expectation and maximization (EM) procedure is used as the natural approach. In this way extended Kalman filter (EKF) and particle filters are avoided.L'objectif de cette thèse est d'étudier le problème de la détection de données dans le système de communication sans fil, à la fois pour le cas de l'information d'état de canal parfaite et imparfaite au niveau du récepteur. Comme on le sait, la complexité de MLSE est exponentielle en la mémoire de canal et la cardinalité de l'alphabet symbole est rapidement ingérable, ce qui force à recourir à des approches sousoptimales. Par conséquent, en premier lieu, nous proposons une nouvelle égalisation itérative lorsque le canal est inconnu à l'émetteur et parfaitement connu au niveau du récepteur. Ce récepteur est basé sur une approche de continuation, et exploite l'idée d'approcher une fonction originale de coût d'optimisation par une suite de fonctions plus dociles et donc de réduire la complexité de calcul au récepteur.En second lieu, en vue de la détection de données sous un canal dynamique linéaire, lorsque le canal est inconnu au niveau du récepteur, le récepteur doit être en mesure d'effectuer conjointement l'égalisation et l'estimation de canal. De cette manière, on formule une représentation de modèle état-espace combiné du système de communication. Par cette représentation, nous pouvons utiliser le filltre de Kalman comme le meilleur estimateur des paramètres du canal. Le but de cette section est de motiver de façon rigoureuse la mise en place du filltre de Kalman dans l'estimation des sequences de Markov par des canaux dynamiques Gaussien. Par la présente, nous interprétons et explicitons les approximations sous-jacentes dans les approaches heuristiques.Enfin, si nous considérons une approche plus générale pour le canal dynamique non linéaire, nous ne pouvons pas utiliser le filtre de Kalman comme le meilleur estimateur. Ici, nous utilisons des modèles commutation d’espace-état (SSSM) comme modèles espace-état non linéaires. Ce modèle combine le modèle de Markov caché (HMM) et le modèle espace-état linéaire (LSSM). Pour l'estimation de canal et la detection de données, l'approche espérance et maximisation (EM) est utilisée comme approche naturelle. De cette façon, le filtre de Kalman étendu (EKF) et les filtres à particules sont évités

A Survey of Religious Values in the Iranian TV Religious News in the Year 1388

Values are to be considered as behavioral guides and the basis of the formation of individuals' inclinations and reactions, and also determining factors in the socio- cultural structure. Sociologists believe that social foundations are rooted in their ideological and value systems. This article intends to make a survey of religious value content of Iranian television news in the year 1388. The method used is content analysis and the statistical domain comprises mostly 9:00 p.m news, channel one; 9:30 p.m. news, channel two; 10 p.m. news, channel 3; 8:00 p.m. news, channel 4, and 12:00 p.m. news, channel 5, in a one-year period using a systematic sampling. The results show that the major media function of religious news of the Iranian TV has been an emphasis on religious behaviors, and the major promotional concern of religious culture has been seeking salvation, defending the oppressed, sticking to Islamic issues, justice, and enjoining virtues and forbidding vices. These have shown themselves in an order of religious, political, cultural, social and ethical values. Other major emphases have been Muslim unity, and observance of hijab and chastity

The allelopathic activity of Festuca arundinacea Shreb. rhizospheric soil is exacerbated under drought stress

This is an author's accepted manuscript of an article due to be published by Springer in the Journal of Soil Science and Plant Nutrition. The accepted manuscript may differ from the final published version. For re-use please see the publisher's terms and conditions.The aims of the current study were to (i) investigate the allelopathic activity of aqueous extracts obtained from the shoots of 16 F.arundinacea genotypes and to identify those with the greatest inhibitory effect (ii) to evaluate the allelopathic activity of the rhizospheric soil of F.arundinacea, under conditions of normal irrigation and severe drought stress, as well as investigating the allelopathic activity of F.arundinacea shoot residues in the soil (iii) the identification of the allelopathic phenolic compounds present in the soil, directly caused by the activity of the roots or released from the shoots residues of F.arundinacea. The results obtained showed that the genotype, extract concentration and the application of drought stress all significantly reduced the germination of Lactuca sativa. As the concentration of the extract increased, a corresponding decrease was observed in the seed germination and growth of the L. sativa seedlings. The highest concentration of the extract (100%) caused the greatest decrease in germination percentage (85%), shootlet length (72.9%), rootlet length (77.04%) and seedling dry weight (63.7%). Drought stress was shown to produce a marked increase in the allelopathic activity of the extracts. The extract obtained from the 23M genotype was shown to exhibit the most inhibitory effect upon the growth of L. sativa. HPLC analysis showed the presence of phenolic compounds in both the rhizosphere and F.arundinacea shoot residues. The identified compounds included p-coumaric acid, apigenin acid, ferulic acid, 4-hydroxybenzoic acid, gallic acid, syringic acid, caffeic acid, vanillic acid, and chlorogenic acid. The results show the presence of more phenolic compounds in the F.arundinacea plant residues compared to the rhizosphere. These data demonstrate the considerable diversity in allelopathic activity of the F.arundinacea genotypes tested, and that it may be feasible to select and breed this species for the purpose of allelopathic weed management

Changes in activities of antioxidant enzymes in radish (Raphanus sativus) seedlings in response to allelopathic effect of safflower (Carthamus tinctorius)

Abstract ROS (Reactive Oxygen Species) production is a usual plant reaction to environmental stresses such as allelopathy. Plants possess antioxidant enzymes to scavenge cells and resist against the ROS. This study was conducted to evaluate changes in antioxidant enzymes (CAT, GPX, APX) in radish seedlings in response to allelopathic effect of safflower root and shoot residues grown under normal irrigation and drought stress. Safflower allelopathic effect led to an increase in antioxidant enzymes activities. GPX activity increased more than CAT and APX. Radish seedlings exposed to safflower residue grown under drought stress showed more antioxidant enzymes activities. Root residues enhanced the activities of antioxidant enzymes greater than shoot. Seedlings exposed to root residues grown under drought stress had the highest level of antioxidant enzymes activities