Social Factors in P2P Energy Trading Using Hedonic Games

Lately, the energy communities have gained a lot of attention as they have the potential to significantly contribute to the resilience and flexibility of the energy system, facilitating widespread integration of intermittent renewable energy sources. Within these communities the prosumers can engage in peer-to-peer trading, fostering local collaborations and increasing awareness about energy usage and flexible consumption. However, even under these favorable conditions, prosumer engagement levels remain low, requiring trading mechanisms that are aligned with their social values and expectations. In this paper, we introduce an innovative hedonic game coordination and cooperation model for P2P energy trading among prosumers which considers the social relationships within an energy community to create energy coalitions and facilitate energy transactions among them. We defined a heuristic that optimizes the prosumers coalitions, considering their social and energy price preferences and balancing the energy demand and supply within the community. We integrated the proposed hedonic game model into a state-of-the-art blockchain-based P2P energy flexibility market and evaluated its performance within an energy community of prosumers. The evaluation results on a blockchain-based P2P energy flexibility market show the effectiveness in considering social factors when creating coalitions, increasing the total amount of energy transacted in a market session by 5% compared with other game theory-based solutions. Finally, it shows the importance of the social dimensions of P2P energy transactions, the positive social dynamics in the energy community increasing the amount of energy transacted by more than 10% while contributing to a more balanced energy demand and supply within the community.Comment: to be submitted to journa

Blockchain based Decentralized Applications: Technology Review and Development Guidelines

Blockchain or Distributed Ledger Technology is a disruptive technology that provides the infrastructure for developing decentralized applications enabling the implementation of novel business models even in traditionally centralized domains. In the last years it has drawn high interest from the academic community, technology developers and startups thus lots of solutions have been developed to address blockchain technology limitations and the requirements of applications software engineering. In this paper, we provide a comprehensive overview of DLT solutions analyzing the addressed challenges, provided solutions and their usage for developing decentralized applications. Our study reviews over 100 blockchain papers and startup initiatives from which we construct a 3-tier based architecture for decentralized applications and we use it to systematically classify the technology solutions. Protocol and Network Tier solutions address the digital assets registration, transactions, data structure, and privacy and business rules implementation and the creation of peer-to-peer networks, ledger replication, and consensus-based state validation. Scaling Tier solutions address the scalability problems in terms of storage size, transaction throughput, and computational capability. Finally, Federated Tier aggregates integrative solutions across multiple blockchain applications deployments. The paper closes with a discussion on challenges and opportunities for developing decentralized applications by providing a multi-step guideline for decentralizing the design of traditional systems and implementing decentralized applications.Comment: 30 pages, 8 figures, 9 tables, 121 reference

ORGANIZATIONAL PERFORMANCE IS HIGHLY INFLUENCED BY MOTIVATION. A CASE STUDY OF THE PUBLIC HEALTH DIRECTORATE

High productivity is of primary concern to individuals, the management of any organization and to the national economy at large. Performance management in the health sector is essential for access to health services and for the provision of quality services. It is generally regarded as a well-known fact that an organization’s employees are a key asset for success. One of the most fascinating questions for specialists, but also one that causes headaches for managers in organizations, is “why are people motivated to do something?”. A human’s ambitions and goals may differ from one person to another, so motivation is a crucial aspect of health care management. Management can guide people to achieve the organization’s goals by identifying their unique qualities and potentials. The main objective of the study was to analyze the factors that motivate and demotivate employees in the Public Health Directorate, in order to find, or demonstrate that workplace satisfaction is influenced by a combination of factors, each of them having their own effect, contributing to the final result, which can be decisive in creating or not an productive equilibrum within the organizations that were subjected to research. Research methods: qualitative-quantitative analysis through the questionnaire-based survey method. Research thesis: Motivation plays a crucial role in organizational performance. This article concluded that not only financial benefits are important to both male and female employees, but also non-financial benefits and Managers must attach significant importance to motivational factors because these are the only ones capable of guaranteeing the success of such an approach

Povezanost polimorfizma rs1437396 gena CCDC88A s poremećajem zloporabe alkohola

Girdin is a protein involved in neuronal migration and hippocampal development. It is encoded by the coiled-coil domain-containing 88A (CCDC88A) gene, located on the short arm of chromosome 2 (2p). The CCDC88A gene is modulated by the intergenic single-nucleotide polymorphism (SNP) of the rs1437396, situated 9.5 kb downstream from its transcription stop site. As recent genome-wide research has associated the T allele of the SNP with increased risk of alcohol use disorder (AUD), we wanted to validate this finding in an independent cohort and to test further for an association with comorbid major depressive disorder (MDD). The study included 226 AUD patients (AUD group), 53 patients with comorbid MDD, and 391 controls selected randomly. The participants were genotyped for the rs1437396 polymorphism using the real-time polymerase chain reaction. The association between the rs1437396 polymorphism and increased risk of AUD and AUD+MDD was tested with logistic regression. Our results show significantly higher frequency of the T risk allele in the AUD group (p=0.027) and even higher in the AUD+MDD group (p=0.016). In conclusion, this is the first study that has validated the association between the rs1437396 polymorphism of the CCDC88A gene and AUD with or without MDD. Studies on larger samples of patients are needed to further investigate the mechanism of this association.Girdin je protein koji sudjeluje u neuronskoj migraciji i razvoju hipokampusa, a kodira ga gen 88A koji sadržava domenu sa smotanom zavojnicom (eng. coiled-coil domain-containing 88A gene, krat. CCDC88A) koja se nalazi na kraćem kraku kromosoma 2 (2p). Gen CCDC88A mijenja se s međugenskim jednonukleotidnim polimorfizmom (eng. single-nucleotide polymorphism, krat. SNP) na mjestu rs1437396, 9,5 kb nizvodno od svojega transkripcijskog završetka. Budući da je u nedavnom istraživanju na razini genoma zamijećena povezanost alela T ovoga polimorfizma s povećanim rizikom od poremećaja zloporabe alkohola (eng. alcohol use disorder), htjeli smo provjeriti tu povezanost u neovisnoj kohorti randomiziranih ispitanika i dodatno ispitati je li polimorfizam povezan i s popratnim povratnim depresivnim poremećajem (eng. major depressive disorder). Ispitivanje je obuhvatilo 226 bolesnika s poremećajem zloporabe alkohola, 51 bolesnika s popratnim povratnim depresivnim poremećajem i 391 kontrolnog ispitanika. Ispitanici su genotipizirani radi utvrđivanja onih koji imaju polimorfizam rs1437396 pomoću polimerazne lančane reakcije u stvarnom vremenu (eng. real-time polymerase chain reaction) te je logaritamskom regresijskom analizom utvrđena povezanost polimorfizma rs1437396 s rizikom od poremećaja zloporabe alkohola s popratnim povratnim depresivnim poremećajem ili bez njega. Naši podatci upućuju na značajno veću učestalost alela T u bolesnika s poremećajem zloporabe alkohola (p=0,027) te na još značajniju učestalost u bolesnika s obama poremećajima (p=0,016). Ovo je prvo istraživanje koje je potvrdilo povezanost između polimorfizma rs1437396 gena CCDC88A i poremećaja zloporabe alkohola s popratnim povratnim depresivnim poremećajem ili bez njega. Daljnja istraživanja mehanizama ove povezanosti potrebno je provesti na većim uzorcima

Smart Grid Management using Blockchain: Future Scenarios and Challenges

Decentralized management and coordination of energy systems are emerging trends facilitated by the uptake of the Internet of Things and Blockchain offering new opportunities for more secure, resilient, and efficient energy distribution. Even though the use of distributed ledger technology in the energy domain is promising, the development of decentralized smart grid management solutions is in the early stages. In this paper, we define a layered architecture of a blockchain-based smart grid management platform featuring energy data metering and tamper-proof registration, business enforcement via smart contracts, and Oracle-based integration of high computational services supporting the implementation of future grid management scenarios. Three such scenarios are discussed from the perspective of their implementation using the proposed blockchain platform and associated challenges: peer to peer energy trading, decentralized management, and aggregation of energy flexibility and operation of community oriented Virtual Power Plants.Comment: Accepted and presented at: 19th RoEduNet Conference: Networking in Education and Research, December 11-12, 202

Quantum-Safe Protocols and Application in Data Security of Medical Records

The use of traditional cryptography based on symmetric keys has been replaced with the revolutionary idea discovered by Diffie and Hellman in 1976 that fundamentally changed communication systems by ensuring a secure transmission of information over an insecure channel. Nowadays public key cryptography is frequently used for authentication in e-commerce, digital signatures and encrypted communication. Most of the public key cryptosystems used in practice are based on integer factorization (the famous RSA cryptosystem proposed by Rivest, Shamir and Adlemann), respectively on the discrete logarithm (in finite curves or elliptic curves). However these systems suffer from two potential drawbacks like efficiency because they must use large keys to maintain security and of course security breach with the advent of the quantum computer as a result of Peter Shor\u27s discovery in 1999 of the polynomial algorithm for solving problems such factorization of integers and discrete logarithm

Expert System for Nutrition Care Process of Older Adults

This paper presents an expert system for a nutrition care process tailored for the specific needs of elders. Dietary knowledge is defined by nutritionists and encoded as Nutrition Care Process Ontology, and then used as underlining base and standardized model for the nutrition care planning. An inference engine is developed on top of the ontology, providing semantic reasoning infrastructure and mechanisms for evaluating the rules defined for assessing short and long term elders’ self-feeding behaviours, to identify unhealthy dietary patterns and detect the early instauration of malnutrition. Our expert system provides personalized intervention plans covering nutrition education, diet prescription and food ordering adapted to the older adult’s specific nutritional needs, health conditions and food preferences. In-lab evaluation results are presented proving the usefulness and quality of the expert system as well as the computational efficiency, coupling and cohesion of the defined ontology

A service-based system for malnutrition prevention and self-management

Malnutrition is considered one of the root causes for the occurrence of other diseases. It is particularly common in the ageing population, where it requires more efficient handling and management to enable longer home independent living. However, to achieve this, a number of related challenges need to be overcome, especially those related to management of health and disease let alone other social and logistical barriers. This paper presents the design of a distributed system that enables homecare management in the context of self-feeding and malnutrition prevention through balanced nutritional intake. The design employs a service-based system that incorporates a number of services including monitoring of activities, nutritional reasoning for assessing feeding habits, diet recommendation for food planning, and marketplace invocation for automating food shopping to meet dietary requirements. The solution is deployed in a small pilot in 12 elder adult houses that, in early results, demonstrates its holistic user-centred scalable approach for malnutrition self-management

Experimental and theoretical study of post-dryout heat transfer in annuli with flow obstacle

An experimental study on post dryout heat transfer regime in annuli with flow obstacles wasconducted in the High-pressure Water Test (HWAT) loop at the Royal Institute of Technologyin Stockholm, Sweden. An annulus with flow obstacles, consisting of two concentric heatedpipes (12.7x24.3) mm, with total heated length equal to 3650 mm was employed as a testsection. The experimental investigations were performed in a wide range of the operationalconditions: mass flux (500-1750) kg/(m2s), inlet subcooling (10-40) K and system pressure(5-7) MPa. The wall superheat was measured at 88 different axial positions. A significanteffect of the flow obstacles on the wall temperature has been observed. A new correlation toevaluate the wall superheat in the post-dryout developing region and downstream of the flowobstacles was suggested. The new approach is taking into account in a combined manner theonset of the dryout point and the flow obstacle location. The coefficients and constants of thecorrelation have been optimized based on 1211 points obtained experimentally. Thecorrelation is applicable starting with the point of the onset of the dryout towards fullydeveloped post-dryout heat transfer regime and shows a correct asymptotical trend. Toaccount for the flow obstacle effect on the critical quality, an expression similar to theLevitan-Lanstman dryout correlation is suggested. The newly developed methodology can beused to predict the wall temperature in the post-dryout heat transfer regime over a wide rangeof mass fluxes and pressures typical for boiling water reactors.QC 20140319</p

Experimental Study of Post-Dryout Heat Transferin Annuli with Flow Obstacles

An experimental study on post dryout heat transfer regime in annuli with flow obstacles was conducted in the High-pressure Water Test (HWAT) loop at the Royal Institute of Technology in Stockholm, Sweden. An annulus consisting of two concentric heated pipes (12.7x24.3) mm, with total heated length equal to 3650 mm was employed as a test section. Three kinds of flow obstacles were used: pin-spacers, cylindrical obstacles and grid obstacles. The experiments performed in the test section with pin-spacers only were considered as the reference case. In two consecutive sets of runs, additional obstacles were placed inside the flow channel while keeping the pin spacers in the same positions. In that way the net effect of obstacles on heat transfer was measured. The experimental investigations were performed in a wide range of the operational conditions: mass flux (500-1750) kg/(m2s), inlet subcooling (10-40) K and system pressure (5-7) MPa. The wall superheat was measured at 88 different axial positions (40 on the inner tube and 48 on the outer tube) for the conditions mentioned above. A local heat transfer coefficient was calculated based on the measured annulus wall temperatures and the saturated fluid (water) properties. The results show an enhancement of the heat transfer coefficient downstream of flow obstacles. The most significant influence has been observed in case of pin spacers. This result is consistent with blockage area of various obstacles, which was the highest in case of pin spacers. The data obtained in more than 200 runs were compared with two pre-dryout and post-dryout correlations. The correlations show a slight over-prediction of the heat transfer coefficient in both pre-dryout and post-dryout regions. The thesis contains a detailed description of experimental procedures as well as an analysis of the results of measurements.  QC 20111024SKC: Post Dryout Regim