Semantic Channel Equalizer: Modelling Language Mismatch in Multi-User Semantic Communications

We consider a multi-user semantic communications system in which agents (transmitters and receivers) interact through the exchange of semantic messages to convey meanings. In this context, languages are instrumental in structuring the construction and consolidation of knowledge, influencing conceptual representation and semantic extraction and interpretation. Yet, the crucial role of languages in semantic communications is often overlooked. When this is not the case, agent languages are assumed compatible and unambiguously interoperable, ignoring practical limitations that may arise due to language mismatching. This is the focus of this work. When agents use distinct languages, message interpretation is prone to semantic noise resulting from critical distortion introduced by semantic channels. To address this problem, this paper proposes a new semantic channel equalizer to counteract and limit the critical ambiguity in message interpretation. Our proposed solution models the mismatch of languages with measurable transformations over semantic representation spaces. We achieve this using optimal transport theory, where we model such transformations as transportation maps. Then, to recover at the receiver the meaning intended by the teacher we operate semantic equalization to compensate for the transformation introduced by the semantic channel, either before transmission and/or after the reception of semantic messages. We implement the proposed approach as an operation over a codebook of transformations specifically designed for successful communication. Numerical results show that the proposed semantic channel equalizer outperforms traditional approaches in terms of operational complexity and transmission accuracy.Comment: This work has been accepted for publication in 2023 IEEE Global Communications Conference (GLOBECOM) SAC: Machine Learning for Communication

Federated Multi-Agent Deep Reinforcement Learning for Dynamic and Flexible 3D Operation of 5G Multi-MAP Networks

This paper addresses the efficient management of Mobile Access Points (MAPs), which are Unmanned Aerial Vehicles (UAV), in 5G networks. We propose a two-level hierarchical architecture, which dynamically reconfigures the network while considering Integrated Access-Backhaul (IAB) constraints. The high-layer decision process determines the number of MAPs through consensus, and we develop a joint optimization process to account for co-dependence in network self-management. In the low-layer, MAPs manage their placement using a double-attention based Deep Reinforcement Learning (DRL) model that encourages cooperation without retraining. To improve generalization and reduce complexity, we propose a federated mechanism for training and sharing one placement model for every MAP in the low-layer. Additionally, we jointly optimize the placement and backhaul connectivity of MAPs using a multi-objective reward function, considering the impact of varying MAP placement on wireless backhaul connectivity.Comment: 2023 IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC

Deljeni delta talasi i primene na sisteme zakona održanja

There are many real models in which unbounded solution to conservation law system occur. Most often we have some kind of delta function in the solution as a result of the accumulation of mass or some other variable. There is no general method of approaching such problems with nonlinearities. This dissertation provides solutions to conservation law systems that contain division by a dependent variable, which is a problematic part when working with measures. For example, a basic model of chromatography and similar chemical processes has a division with a variable that is unbounded in some cases. The denition of the split delta shock and the general method of using it in such systems is given. Finally, the solution for the singular chromatography model is given.  Postoji mnogo realnih modela u kojima se javljaju neoranicena resenja zakona odrzanja. Najcesce imamo neku vrstu delta funkcije u resenju kao posledicu nagomilavanja mase ili neke druge velicine. Ne postoji opsti metod prilaza takvim problemima sa nelinearnostima. U ovoj disertaciji su data resenja problema zakona odrzanja koja sadrze delenje zavisnom promenljivom, sto je problematican deo kod rada sa merama. Na primer, osnovni model hromatograje i slicnih hemijskih procesa ima delenje promenljivom koja je neogranicena u nekim slucajevima. Data je denicija inverza delenjog delta udarnog talasa i opsti metod primene u takvim sistemima. Na kraju je dato resenje kod modela singularne hromatograje.

Deljeni delta talasi i primene na sisteme zakona održanja

There are many real models in which unbounded solution to conservation law system occur. Most often we have some kind of delta function in the solution as a result of the accumulation of mass or some other variable. There is no general method of approaching such problems with nonlinearities. This dissertation provides solutions to conservation law systems that contain division by a dependent variable, which is a problematic part when working with measures. For example, a basic model of chromatography and similar chemical processes has a division with a variable that is unbounded in some cases. The denition of the split delta shock and the general method of using it in such systems is given. Finally, the solution for the singular chromatography model is given.  Postoji mnogo realnih modela u kojima se javljaju neoranicena resenja zakona odrzanja. Najcesce imamo neku vrstu delta funkcije u resenju kao posledicu nagomilavanja mase ili neke druge velicine. Ne postoji opsti metod prilaza takvim problemima sa nelinearnostima. U ovoj disertaciji su data resenja problema zakona odrzanja koja sadrze delenje zavisnom promenljivom, sto je problematican deo kod rada sa merama. Na primer, osnovni model hromatograje i slicnih hemijskih procesa ima delenje promenljivom koja je neogranicena u nekim slucajevima. Data je denicija inverza delenjog delta udarnog talasa i opsti metod primene u takvim sistemima. Na kraju je dato resenje kod modela singularne hromatograje.

Towards Sustainable Food System in Qatar: Household Food Waste and Consumption Behavior

It has been proofed that food wastage can be recognized at all level of food life cycle i.e. harvesting, manufacturing, distributing however, the largest contribution to food waste is the consumption stage by household. According to Parfitt et al, 2010; WRI, 2013 “household food waste” is define as the total losses that occur at the end of food lifecycle, which is final consumption, we consider the issue of waste of food as a deeply rooted issue of consumption behaviors, (Den 2008; Bowman 2007; Dogs 2002), and many commentators argue that domestic food waste is strongly influenced by consumer behaviors (Wharton, 2014). In the Arab countries, especially in the Gulf countries, high levels of food waste of recorded due to the social customs and traditions that control consumption patterns. Research efforts on the waste of food in the State of Qatar is very few and does not cover all Food waste, production and consumption chain, which start from production through delivery, storage, packaging, selling, and consumption. Through computer assisted telephone interview (CATI) with 1684 respondents This study covered the stage after purchase and consumption, aimed to understand the attitudes and behavior of individuals in Qatar towards food waste , and to identify types of food are often wasted and estimated the amount of waste as well. Survey respondents provided reason of food waste and Results indicate that people have an awareness regard food waste Furthermore; the study found out having more children was associated with reduced food waste perception and high-income households were strongly associated with increase in perception of food wastage as the income increases. Moreover, family give the persons a sense of responsibility towards food waste

Barley breeding for quality improvement in Tunisia

This study was initiated to assess the effectiveness of three selection procedures applied in the early  segregating generations of barley crosses for quality traits. The selection procedures were pedigree selection (PS), bulk selection (BS) and single seed descent selection (SSD). Selection was operated in F2’s crosses. Field trials were conducted with 19 F3 crosses of barley in two different environments, a sub-humid  environment at Beja and a semi-arid one at Kef. Heading date (HD), thousand kernel weight (TKW), protein  content (PC), â-glucan content (BG) and husk percentage (HP) were evaluated. Data were subjected to an  additive main effects and multiplicative interaction (AMMI) model to determine the efficiency of each method of selection for the proper environment. The results show that the AMMI model generated predictive  optimizing selection method. The pedigree selection was more efficient in high input environment, while the bulk method was very effective for the selection of kernel weight in target environment.Key words: Additive main effect and multiplicative interaction (AMMI) model, Barley, breeding methods, efficiency of selection, quality traits

State-of-the-Art on the Marine Current Turbine System Faults

This chapter deals with the state of the art on the marine current turbine (MCT) system faults. Indeed, the MCT structure consists of a marine turbine, a generator (permanent magnet synchronous generator (PMSG) or doubly fed induction generator (DFIG)), and a PWM power converter. Nevertheless, these systems are exposed to functional and environmental severe conditions. Firstly, the power increase leads to a higher current and/or voltage. Second, the installation of the MCT system under the sea and the existence of the swell and wave imply harmonic current speeds. In fact, several faults (related to the turbine, the generator, the blades, and the converters) can occur in the MCT system. Most of these faults generate the speed and the torque oscillations, which can lead to mechanical vibrations and the rapid destruction of the insulating material generator. Consequently, MCT system performances can be degraded

The Impact of Partial Sleep Deprivation on the Diurnal Variations of Cognitive Performance in Trained Subjects

AbstractThe aim of this study was to investigate the effect of partial sleep deprivation on the diurnal variations of cognitive performance of handball goalkeepers. Twelve handball goalkeepers (18.5±1.7 years; 8.3±2.4 years of experiment) performed 3 cognitive tasks by the use of the reaction time (RT), the stroop, and the barrage tests (to evaluate the RT, the selective and supported attention respectively) following 2 situations of sleep deprivation (in the beginning or in the end of the night) and a control situation. The tests were performed at 08:00 and 16:00. Our results showed an increased RT and a fall of the level of the attention after the partial sleep deprivation in the afternoon hours. However, the partial sleep deprivation didn’t affect the morning cognitive performance. In conclusion, partial sleep deprivation affects the diurnal variation of cognitive performance by increasing the RT and reducing the attentional capacities in the afternoon hours