Skalabilna implementacija dekodera po normi MPEG korištenjem tokovnog programskog jezika

In this paper, we describe a scalable and portable parallelized implementation of a MPEG decoder using a streaming computation paradigm, tailored to new generations of multi--core systems. A novel, hybrid approach towards parallelization of both new and legacy applications is described, where only data--intensive and performance--critical parts are implemented in the streaming domain. An architecture--independent \u27StreamIt\u27 language is used for design, optimization and implementation of parallelized segments, while the developed \u27StreamGate\u27 interface provides a communication mechanism between the implementation domains. The proposed hybrid approach was employed in re--factoring of a reference MPEG video decoder implementation; identifying the most performance--critical segments and re-implementing them in \u27StreamIt\u27 language, with \u27StreamGate\u27 interface as a communication mechanism between the host and streaming kernel. We evaluated the scalability of the decoder with respect to the number of cores, video frame formats, sizes and decomposition. Decoder performance was examined in the presence of different processor load configurations and with respect to the number of simultaneously processed frames.U ovom radu opisujemo skalabilnu i prenosivu implementaciju dekodera po normi MPEG ostvarenu korištenjem paradigme tokovnog računarstva, prilagođenu novim generacijama višejezgrenih računala. Opisan je novi, hibridni pristup paralelizaciji novih ili postojećih aplikacija, gdje se samo podatkovno intenzivni i računski zahtjevni dijelovi implementiraju u tokovnoj domeni. Arhitekturno neovisni jezik StreamIt koristi se za oblikovanje, optimiranje i izvedbu paraleliziranih segmenata aplikacije, dok razvijeno sučelje \u27StreamGate\u27 omogućava komunikaciju između domena implementacije. Predloženi hibridni pristup razvoju paraleliziranih aplikacija iskorišten je u preoblikovanju referentnog dekodera video zapisa po normi MPEG; identificirani su računski zahtjevni segmenti aplikacije i ponovno implementirani u jeziku StreamIt, sa sučeljem \u27StreamGate\u27 kao poveznicom između slijedne i tokovne domene. Ispitivana su svojstva skalabilnosti s obzirom na ciljani broj jezgri, format video zapisa i veličinu okvira te dekompoziciju ulaznih podataka. Svojstva dekodera  su praćena u prisustvu različitih opterećenja ispitnog računala, i s obzirom na broj istovremeno obrađivanih okvira

Framework for Federated Learning Open Models in e-Government Applications

Using open data and artificial intelligence in providing innovative public services is the focus of the third generation of e-Government and supporting Internet and Communication Technologies systems. However, developing applications and offering open services based on (open) machine learning models requires large volumes of private, open, or a combination of both open and private data for model training to achieve sufficient model quality. Therefore, it would be beneficial to use both open and private data simultaneously to fully use the potential that machine learning could grant to the public and private sectors. Federated learning, as a machine learning technique, enables collaborative learning among different parties and their data, being private or open, creating shared knowledge by training models on such partitioned data without sharing it between parties in any step of the training or inference process. This paper provides a practical layout for developing and sharing machine learning models in a federative and open manner called Federated Learning Open Model. The definition of the Federated Learning Open Model concept is followed by a description of two potential use cases and services achieved with its usage, one being from the agricultural sector with the horizontal dataset partitioning and the latter being from the financial sector with a dataset partitioned vertically

Autonomous Mobile Mailbox Model for Communication Cost Reduction

This paper presents a cost-reductive communication schema for distributed multi-agent environments containing mobile agents. Communication cost reduction is achieved by employing autonomous mobile mailbox as a message-relay system component. Beneficial modes of mobile mailbox behavior are identified under various operational conditions. A mobile mailbox model is proposed and simulation conducted in order to verify its usability

Air Pollution Dispersion Modeling in Port Areas

For the last couple of decades, environmental protection awareness within port areas is gaining ever more importance. Ports can have a tremendous impact on the environment, especially in terms of air pollution. The main pollution sources are various port activities such as road and rail traffic, cargo handling and marine vessel operations. Air quality models can be of great help in estimating the effect on the ambient air quality from one or more sources emitting pollutants to the atmosphere. One of those models is the widely used Gaussian Plume dispersion approach. Based on existing measurements and port activity data, models can simulate the dispersion of air pollutants caused by activities and operations taking place within the port. By using historical data, they can simulate the current state of the air quality in the port and with the help of weather predictions simulate possible future situation. Simulations can assist the port manager/operator in the decision-making process in order to optimize various activities within the port and minimize their impact on the environment. One of the main objectives of the Horizon 2020 Project PIXEL (Port IoT for environmental leverage) is the deployment of environmental pollution models which can aid in the decision-making processes within the port domain. This paper reviews the current advances in the field of air pollution modelling with a special emphasis on port scenarios

Air Pollution Dispersion Modeling in Port Areas

For the last couple of decades, environmental protection awareness within port areas is gaining ever more importance. Ports can have a tremendous impact on the environment, especially in terms of air pollution. The main pollution sources are various port activities such as road and rail traffic, cargo handling and marine vessel operations. Air quality models can be of great help in estimating the effect on the ambient air quality from one or more sources emitting pollutants to the atmosphere. One of those models is the widely used Gaussian Plume dispersion approach. Based on existing measurements and port activity data, models can simulate the dispersion of air pollutants caused by activities and operations taking place within the port. By using historical data, they can simulate the current state of the air quality in the port and with the help of weather predictions simulate possible future situation. Simulations can assist the port manager/operator in the decision-making process in order to optimize various activities within the port and minimize their impact on the environment. One of the main objectives of the Horizon 2020 Project PIXEL (Port IoT for environmental leverage) is the deployment of environmental pollution models which can aid in the decision-making processes within the port domain. This paper reviews the current advances in the field of air pollution modelling with a special emphasis on port scenarios

Adaptive Object Oriented Distributed Computer Systems

Ovaj rad opisuje načine i mehanizme prilagodbe raspodijeljenih računalnih sustava temeljenih na arhitekturi CORBA. Sukladno potrebi prilagodbe novije generacije raspodijeljenih sustava promjenama u radnom okruženju, osmišljen je i izrađen sustav praćenja njihova rada. Objašnjene su tehnologije raspodijeljenih sustava s posebnim osvrtom na arhitekturu CORBA. Analizirani su problemi svojstveni fazama oblikovanja, izgradnje i korištenja sustava, te njihovo rješavanje temeljeno na postupcima nadgledanja. Dan je kraći pregled postojećih metoda nadgledanja i njihovih svojstava. Izložen je pojam računalne refleksije i mehanizmi metaprogramiranja u sustavu CORBA. Detaljno je opisana građa i izvedba usluge praćenja rada raspodijeljenog sustava, načini njena korištenja, te analizirana njena svojstva. Naposljetku, predstavljen je primjer praćenja i upravljanja radom postojećeg sustava korištenjem razvijene usluge.This thesis addresses methods and mechanisms of CORBA-based distributed system adaptation. Regarding the need of adaptation to environmental changes present in new generation of distributed systems, a new monitoring system has been designed and implemented. Distributed system technologies have been explained, primarily focusing on CORBA. Problems present in design, implementation and operation phases have been analyzed and solutions based on system monitoring proposed. Concept of reflection in computer systems and CORBA related meta-programming mechanisms have been elucidated. Design and implementation of the CORBA monitoring service have been described in detail, usage explained and properties analyzed. Finally, an example of monitoring and application steering on the existing distributed system has been presented using the developed service

Adaptive Object Oriented Distributed Computer Systems

Ovaj rad opisuje načine i mehanizme prilagodbe raspodijeljenih računalnih sustava temeljenih na arhitekturi CORBA. Sukladno potrebi prilagodbe novije generacije raspodijeljenih sustava promjenama u radnom okruženju, osmišljen je i izrađen sustav praćenja njihova rada. Objašnjene su tehnologije raspodijeljenih sustava s posebnim osvrtom na arhitekturu CORBA. Analizirani su problemi svojstveni fazama oblikovanja, izgradnje i korištenja sustava, te njihovo rješavanje temeljeno na postupcima nadgledanja. Dan je kraći pregled postojećih metoda nadgledanja i njihovih svojstava. Izložen je pojam računalne refleksije i mehanizmi metaprogramiranja u sustavu CORBA. Detaljno je opisana građa i izvedba usluge praćenja rada raspodijeljenog sustava, načini njena korištenja, te analizirana njena svojstva. Naposljetku, predstavljen je primjer praćenja i upravljanja radom postojećeg sustava korištenjem razvijene usluge.This thesis addresses methods and mechanisms of CORBA-based distributed system adaptation. Regarding the need of adaptation to environmental changes present in new generation of distributed systems, a new monitoring system has been designed and implemented. Distributed system technologies have been explained, primarily focusing on CORBA. Problems present in design, implementation and operation phases have been analyzed and solutions based on system monitoring proposed. Concept of reflection in computer systems and CORBA related meta-programming mechanisms have been elucidated. Design and implementation of the CORBA monitoring service have been described in detail, usage explained and properties analyzed. Finally, an example of monitoring and application steering on the existing distributed system has been presented using the developed service

Adaptive Object Oriented Distributed Computer Systems

Ovaj rad opisuje načine i mehanizme prilagodbe raspodijeljenih računalnih sustava temeljenih na arhitekturi CORBA. Sukladno potrebi prilagodbe novije generacije raspodijeljenih sustava promjenama u radnom okruženju, osmišljen je i izrađen sustav praćenja njihova rada. Objašnjene su tehnologije raspodijeljenih sustava s posebnim osvrtom na arhitekturu CORBA. Analizirani su problemi svojstveni fazama oblikovanja, izgradnje i korištenja sustava, te njihovo rješavanje temeljeno na postupcima nadgledanja. Dan je kraći pregled postojećih metoda nadgledanja i njihovih svojstava. Izložen je pojam računalne refleksije i mehanizmi metaprogramiranja u sustavu CORBA. Detaljno je opisana građa i izvedba usluge praćenja rada raspodijeljenog sustava, načini njena korištenja, te analizirana njena svojstva. Naposljetku, predstavljen je primjer praćenja i upravljanja radom postojećeg sustava korištenjem razvijene usluge.This thesis addresses methods and mechanisms of CORBA-based distributed system adaptation. Regarding the need of adaptation to environmental changes present in new generation of distributed systems, a new monitoring system has been designed and implemented. Distributed system technologies have been explained, primarily focusing on CORBA. Problems present in design, implementation and operation phases have been analyzed and solutions based on system monitoring proposed. Concept of reflection in computer systems and CORBA related meta-programming mechanisms have been elucidated. Design and implementation of the CORBA monitoring service have been described in detail, usage explained and properties analyzed. Finally, an example of monitoring and application steering on the existing distributed system has been presented using the developed service

Introducing Open Data Concepts to STEM Students Using Real-World Open Datasets

While open data concepts become more important in our society, education about its benefits and technical issues is still behind the practice. Students of STEM disciplines should be introduced to open data during their education. The Open Computing course, completely redesigned in the new Computing curriculum, introduces open data concepts, providing both the basics and advanced topics, from technical to social and legal viewpoints. Among the several educational activities, one was particularly useful for understanding the needs and implications of using open data: a synchronous group activity where students had to choose a societal issue, find and analyze two open datasets that would help gaining insight into this issue, assess interdisciplinarity approaches and stakeholders, and finally propose the added value emerging from the solution. In a short amount of time needed, this activity – which tackled multiple aspects of the problem - brought a clearer insight into the topic, building upon the conventional lectures. Students highly graded such an approach to their education, where they had to construct their knowledge by the group experience. A similar group activity appeared to be useful in the context of open data PhD training and might also be used in other disciplines and domains