The Necessity of Adoption of New National Regulations to Prevent the Pollution of Croatian Coastal Sea by Sewage from Various Vessels

This paper addresses international, Croatian and EU legislation on the prevention of sea water pollution by sewage from vessels. The paper also highlights the disadvantages of international legislation on the protection of coastal sea against pollution by vessel sewage. International legislation is enacted at the global level rather than for each individual coastal sea due to each sea having different exposure to pollution. Either the insufficiently comprehensive national legislation needs to be amended or, more suitably and effectively in the case of the Republic of Croatia, new rules regulating the prevention of coastal sea pollution at the national level and the prevention of negative influence on the marine eco-system, human health and economy established

Abstractions for Solving Consensus and Related Problems with Byzantine Faults

We become increasingly dependent on online services; therefore, their availability and correct behavior become increasingly important. Software replication is a popular technique for ensuring that computer systems continue to provide a correct service even when some of their components fail. By replicating a service on multiple servers, clients are guaranteed that even if some replica fails, the service is still available. At the core of software replication is the consensus problem, where a set of processes has to agree on a single value. A large number of consensus algorithms for different system models have been proposed. The most general system models (for which consensus is solvable) do not make strong assumptions on the synchrony (allow period of asynchrony) and assume that a subset of processes can fail completely arbitrarily (Byzantine faults). However, solving consensus in the presence of arbitrary faults and asynchrony is hard and demands sophisticated algorithms. Most of the existing consensus algorithms that deal with arbitrary faults are monolithic and developed from scratch, or by modifying existing algorithms in a non-modular manner. As a consequence, these algorithms are rather complex and hard to understand. We impute this complexity to the lack of adequate abstractions. The motivation of this thesis is suggesting abstractions that simplify the understanding of existing consensus algorithms with arbitrary faults and allow modular design of novel algorithms. The thesis also aims to clarify relations between consensus and the total-order broadcast problem in the presence of arbitrary faults. In the context of the consensus problem with arbitrary process faults, the literature distinguishes (1) authenticated Byzantine faults, where messages can be signed by the sending process, and (2) Byzantine faults, where there is no mechanism for signatures. Consensus protocols that assume Byzantine faults (without authentication) are harder to develop and prove correct than algorithms that consider authenticated Byzantine faults, even when they are based on the same idea. We propose an abstraction called weak interactive consistency (or WIC), that allows us to design consensus algorithms that can be instantiated into algorithms for authenticated Byzantine faults (signed messages) and algorithms for Byzantine faults. In other words, WIC unifies Byzantine consensus algorithms with and without signatures. This is illustrated on two seminal Byzantine consensus algorithms: the Castro-Liskov PBFT algorithm (no signatures) and the Martin-Alvisi FaB Paxos algorithms (signatures). WIC allows a very concise expression of these two algorithms. Furthermore, WIC turns out to be fundamental abstraction for solving consensus in the transmission fault model. The transmission fault model captures faults without blaming a specific component for the fault, and it is well-adapted to dynamic and transient faults. Using WIC we designed a consensus algorithm that overcomes limitations of all existing solutions to consensus in this model, which assume the synchronous system model, or require strong conditions for termination that exclude the case where all messages of a process can be corrupted. Then we go one step further in unifying consensus algorithms by proposing a generic consensus algorithm that highlights, through well chosen parameters, the core mechanisms of a number of well-known consensus algorithms including Paxos, OneThirdRule, PBFT and FaB Paxos. Interestingly, the generic algorithm allows us to identify a new Byzantine consensus algorithm that requires n > 4b, in-between the requirement n > 5b of FaB Paxos and n > 3b of PBFT (b is the maximum number of Byzantine processes). Afterwards, we study the relation between consensus and total-order broadcast in the presence of Byzantine faults. Total-order broadcast is defined for a set of processes, where each process can broadcast messages, with the guarantee that all processes in this set see the same sequence of messages. Among the several definitions of Byzantine consensus that differ only by their validity property, we identify those equivalent to total-order broadcast. We also give the first deterministic total-order broadcast reduction to consensus with constant time complexity with respect to consensus. Finally, we consider state-machine replication (SMR) with Byzantine faults. State-machine replication is a general approach for replicating services that can be modeled as a state machine. The key idea of this approach is to guarantee that all replicas start in the same state and then apply requests from clients in the same order, thereby guaranteeing that the replica states do not diverge. Recent studies has shown that most BFT-SMR algorithms do not actually perform well under performance attacks by Byzantine processes. We propose a new BFT-SMR algorithm, called BFT-Mencius, that guarantees, assuming a partially synchronous system model, that the latency of updates of correct processes is eventually upper-bounded, even under performance attacks by Byzantine processes. BFT-Mencius is a modular, signature-free algorithm based on a new communication primitive called Abortable Timely Announced Broadcast (ATAB). We evaluate the performance of BFT-Mencius in cluster settings, and show that it performs comparably to the state-of-the-art algorithms such as PBFT and Spinning in fault-free configurations and outperforms these algorithms under performance attacks by Byzantine processes

Razvoj softverskog alata za trodimenzionalnu rekonstrukciju i biomehaničku analizu zida aorte

REZIME: Aneurizma trbušne (abdominalne) aorte (AAA) predstavlja javljanje lokalizovanog proširenja najvećeg arterijskog krvnog suda u trbuhu. Proširenje se javlja kao posledica smanjivanja čvrstine i elastičnosti zida aorte što direktno utiče na njeno istezanje. Najopasnija komplikacija AAA je njeno pucanje koje predstavlja ozbiljan klinički problem, sa smrtnošću od 90%, čime je i svrstan među najčešće uzroke smrti. Trenutne kliničke metode za procenu rizika pucanja AAA su nedovoljno pouzdane i koje, u ne malom broju slučajeva, daju loše rezultate. Strukturna analiza biomehanike AAA pacijenata pruža značajnije i pouzdanije dijagnostičke parametre koji mogu poslužiti u predviđanju toka i ishoda ove bolesti. Prisutna mnogobrojna rešenja za biomehaničku analizu AAA, koje je neophodno kombinovati, i dalje pružaju neodgovarajuće biomehaničke modele AAA zbog nekompatibilnosti, nepouzdanosti i potrebe stručnosti za njihovo korišćenje. Predmet teze je primena inženjerskog pristupa u razvoju mehanizama neophodnih za prikupljanje informacija koji daju bolji uvid u trenutno stanje AAA kod pacijenta i rizik od pucanja iste, ali pre svega, razvoj softverskog alata koji objedinjuje sve te mehanizme u jedan konačan i upotrebljiv proizvod. To podrazumeva razvoj algoritama za vizuelizaciju medicinskih slika, za poluatomatsku i automatsku segmentaciju regiona lumena i intraluminalnog tromba AAA, generisanje trodimenzionalne heksaedarske mreže konačnih elemenata aorte, određivanje njenih materijalnih karakteristika na nivou pacijenta, vizuelizaciju ali interakciju za adekvatno korisničko iskustvo . Jedna od glavnih prednosti ovog alata je što će biti osposobljen za izvođene numeričkih simulacija, korišćenjem metode konačnih elemenata, i time dati bolji uvid u stanje pacijenta, sa biomehaničkog aspekta, koji je nemoguće ostvariti konvencionalnim metodama.ABSTRACT: Abdominal aortic aneurysm represents local dilatation of largest aorta located in the abdomen. Dilatation occurs as result of wall stiffness and elasticity degradation which directly influence process expanding. Most serious complication is AAA rupture which is major clinical issue with mortality above 90% which position this disease as most common cause of death at elderly population. Current diagnostic methods for AAA rupture risk assessment are not reliable which very often provides bad outcomes. Results produced by AAA structural biomechanical analysis are more secure and of greater importance as diagnostic parameters providing one more detailed approach in estimating the nature of this disease. Variety technical solutions offers biomechanical models of inappropriate accuracy mostly because of present incompatibility, unreliability and requirement of technical experience. Focus of work presented in this thesis is appliance of engineering approach in developing technical solutions required for estimation of biomechanical quantities which provides better overview of the current state of patient specific AAA and risk of rupture combined as software solution which offer the symbiosis of required mechanism in form of the software end product. That includes developing algorithms for medical images visualization, semiautomatic and automatic segmentation, generation of three-dimensional aorta models in form of the appropriate hexahedral meshes, estimation of tissue material characteristics on patient specific basis, visualization and interaction in order to provide user acceptable and friendly experience. One of the main advantages of developed software system is its capability to perform finite element method numerical simulations giving better insight in patient’s condition from biomechanical point of view which is impossible to provide by convectional approach

Implementing the AWS Academy curriculum into a cloud computing course

This study was supported by the Ministry of Education, Science and Technological Development of the Republic of Serbia, and these results are parts of the Grant No. 451-03-68/2022-14/200132 with University of Kragujevac - Faculty of Technical Sciences Čačak.Companies are moving towards the cloud more than ever, and startups are getting full support from cloud providers in terms of consulting and credits, with developers adopting new programming models shifting further away from traditional technologies. However, teaching cloud computing is still a major undertaking, as it is still difficult choosing the right tools, learning platforms, and creating curriculums to cover such a wide body of knowledge. One of the newest additions to teaching cloud is the AWS Academy curriculum and learner labs and long-running labs. In this paper, the results of implementing the AWS Academy with a hybrid model at Faculty of Technical Sciences are observed. Post-semester evaluation showed up that use of this initiative’s resources can fully support an introductory course in cloud computing. However the proper adaptation is needed to fully utilise the platform and achieve the learning goals.Publishe

Morfološka i molekularna karakterizacija Fusarium graminearum Schwabe kao prouzrokovača truleži semena Hyssopus officinalis L.

Symptoms of seed rot of Hyssopus officinalis L. were noticed during seed health testing in 2018. According to morphological and cultural characteristics, isolates belong to Fusarium spp. and Alternaria spp.. Based on morphological and pathogenic properties, as well as sequence analysis, isolate designated as 4003/3 wаs identified as Fusarium graminearum deposited in NCBI gene bank under Acc. Number MK061542. To our knowledge F. graminearum as the causal agent of Hyssopus officinalis L. seed rot in Serbia was noticed for the first time.Simptomi truleži semena Hyssopus officinalis L. primećeni su tokom ispitivanja zdravstvenog stanja semena 2018. godine. Prema morfološkim i odgajivačkim karakteristikama izolati pripadaju vrstama Fusarium spp. i Alternatia spp.. Identifikacija Fusarium spp. potvrđena je primenom lančane reakcije polimeraze sa parom prajmera EF1 i EF2, pri čemu je amplifikacija i sekvencioniranje gena TEF-1α izvršena za izolat JBL4003/3 (MK061542.1), čime je potvrđeno da je izop novi domaćin vrste Fusarium graminearum Schwabe

Comparative analysis of limit bearing capacity of a continuous beam applying the limit and shakedown analysis depending on the character of the load

Primjenom poučaka analize granične nosivosti moguće je odrediti granično opterećenje linearnih sustava izloženih opterećenju koje se proporcionalno povećava dok ne dođe do loma. U slučaju kada su nosivi sustavi izloženi ponovljenom opterećenju, postavke granične analize ne daju odgovarajuća rješenja. Zbog toga su simultano razvijeni adaptacijski poučci koji su omogućili sigurno određivanje graničnog opterećenja. U ovom je radu određeno opterećenje loma kontinuiranog nosača s dva polja, primjenom statičkog i kinematičkog poučka granične analize i metode adaptacije. Pokazana je također razlika između vrijednosti sila loma ovisno o karakteru opterećenja i vrijednosti raspona nosača da bi se procijenila opravdanost primjene metode adaptacije u analizi granične nosivosti nosača.Applying the theorems of structural limit analysis it is possible to determine the limit load of linear systems exposed to load which increases proportionally until the formation of failure mechanism. In the case when beam systems are exposed to repeated load, the limit theorems do not yield the adequate solutions, thus the adaptation theorems which made safe limit load determination possible were developed simultaneously. In this paper, applying the static and kinematic theorem of limit and shakedown analysis, the failure load of continuous beam with two spans has been determined. Also displayed is the difference between the values of failure forces depending on the character of load and the beam span value in order to assess justification for application of the shakedown method in the analysis of the limit bearing capacity of the beams

Comparative analysis of limit bearing capacity of a continuous beam applying the limit and shakedown analysis depending on the character of the load

Primjenom poučaka analize granične nosivosti moguće je odrediti granično opterećenje linearnih sustava izloženih opterećenju koje se proporcionalno povećava dok ne dođe do loma. U slučaju kada su nosivi sustavi izloženi ponovljenom opterećenju, postavke granične analize ne daju odgovarajuća rješenja. Zbog toga su simultano razvijeni adaptacijski poučci koji su omogućili sigurno određivanje graničnog opterećenja. U ovom je radu određeno opterećenje loma kontinuiranog nosača s dva polja, primjenom statičkog i kinematičkog poučka granične analize i metode adaptacije. Pokazana je također razlika između vrijednosti sila loma ovisno o karakteru opterećenja i vrijednosti raspona nosača da bi se procijenila opravdanost primjene metode adaptacije u analizi granične nosivosti nosača.Applying the theorems of structural limit analysis it is possible to determine the limit load of linear systems exposed to load which increases proportionally until the formation of failure mechanism. In the case when beam systems are exposed to repeated load, the limit theorems do not yield the adequate solutions, thus the adaptation theorems which made safe limit load determination possible were developed simultaneously. In this paper, applying the static and kinematic theorem of limit and shakedown analysis, the failure load of continuous beam with two spans has been determined. Also displayed is the difference between the values of failure forces depending on the character of load and the beam span value in order to assess justification for application of the shakedown method in the analysis of the limit bearing capacity of the beams

Pojava, identifikacija i filogenetska analiza Fusarium proliferatum prouzrokovača truleži semena pasulja (Phaseolus vulgaris L.) u Srbiji

During the routine quality control analysis on bean seeds in 2015, Fusarium fungal infection was observed on an average of 17% of the bean seed. The objective of this paper was isolation and identification of Fusarium sp. based on the pathogen's morphological and molecular characteristics. Morphological identification of Fusarium isolates was performed on PDA and CLA. DNA of 14 Fusarium sp. isolates was extracted directly from the mycelium (~ 100 mg wet weight), with a Dneasy Plant Mini Kit (Qiagen, Hilden, Germany). Following DNA extraction, the translation elongation factor 1-alpha region was amplified by PCR with the primer pair EF1 and EF2. An amplicon of 700 bp was amplified in all tested isolates. Identification of one isolate was performed by sequencing the translation elongation factor EF-1a gene. Completed morphological and molecular characteristics of isolates, as well as the results of sequencing confirmed that Fusarium proliferatum was the causal agent of bean seed rot.Tokom rutinske kontrole kvaliteta semena pasulja (Phaseolus vulgaris L.) u 2015. godini ustanovljeno je prisustvo Fusarium sp. u visokom procentu, u proseku 17%. Cilj ovog rada bio je izolacija i identifikacija prouzrokovača truleži semena pasulja, na osnovu morfoloških i molekularnih karakteristika patogena. Odgajivačke karakteristike 14 odabranih izolata ocenenjene su na PDA i CLA podlogama. Ekstrakcija DNK 14 odabranih izolata obavljena je direktno iz 100 mg sveže micelije, korišćenjem Dneasy Plant Mini Kit (Qiagen, Hilden, Nemačka). Amplifikacija DNK obavljena je pomoću PCR korišćenjem para prajmera EF1 i EF2. U svim proučavanim izolatima formirani su amplikoni veličine 700 bp. Identifikacija jednog odabranog izolata izvršena je sekvenciranjem translacionog faktora EF-1 a gena. Na osnovu dobijenih rezultata ustanovljeno je da je prouzrokovač truleži semena pasulja Fusarium proliferatum