A Two-Dimensional Nitrogen Fertilization Model for Irrigated Crops in Turkey

The main aim of this scientific work was to develop a theoretical model for calculation of nitrogen (N) fertilization of crops. The model is based on the N fertilization plans which had been prepared for the requirements of the Technical Assistance Project entitled “Implementation of Nitrates Directive in Turkey”. It  was compiled and tested in irrigated corn crop. This has the possibility to calculate the amount of nitrogen which is required in a wide range of mean annual rainfall. It was tested for areas which receive mean annual rainfall 500-1500 mm and nitrates content in irrigation waters was 10 mg/L. Crop requirements in water are not covered by rainfall in the growing period of crops, due to uneven annual distribution during growing period and additional water is needed by mean of irrigation. Soil texture affects strongly the required quantity of soil nutrients and irrigation water and for this reason, the following textural soil classes were used: light, moderate, heavy texture and soils with organic matter 6% and clay 30%.This model is the basis for the development of auser friendly graphic environment which was built in Python 3.5. This tool can calculate the required Nitrogen for all possible triplets(soil class, annual rainfall, nitrogen from irrigation water) required for every annual crop. The user has simply to choose the crop type, the soil class, then to type the annual rainfall and the N content of irrigation water. The model uses as inputs three variables, namely the qualitative soil class and two quantitative annual rainfall (in mm/y) and nitrates inputs from irrigation (content in mg/L) and returns as an output the required Nitrogen in kg/da (1 da=1000 m2) for the described instance. Results have indicated that the requirements of nitrogen fertilization for corn varied among soil classes although irrigation water had the same nitrates concentration. This can be attributed mainly to different potential of nitrates leaching and N mineralization

5G for Vehicular Use Cases: Analysis of Technical Requirements, Value Propositions and Outlook

The fifth generation (5G) of wireless networks promises to meet the stringent requirements of vehicular use cases that cannot be supported by previous technologies. However, the stakeholders of the automotive industry (e.g., car manufacturers and road operators) are still skeptical about the capability of the telecom industry to take the lead in a market that has been dominated by dedicated intelligent transport systems (ITS) deployments. In this context, this paper constructs a framework where the potential of 5G to support different vehicular use cases is thoroughly examined under a common format from both the technical and business perspectives. From the technical standpoint, a storyboard description is developed to explain when and how different use case scenarios may come into play (i.e., pre-conditions, service flows and post-conditions). Then, a methodology to trial each scenario is developed including a functional architecture, an analysis of the technical requirements and a set of target test cases. From the business viewpoint, an initial analysis of the qualitative value perspectives is conducted considering the stakeholders, identifying the pain points of the existing solutions, and highlighting the added value of 5G in overcoming them. The future evolution of the considered use cases is finally discussed

Design, Development and Evaluation of 5G-Enabled Vehicular Services:The 5G-HEART Perspective

The ongoing transition towards 5G technology expedites the emergence of a variety of mobile applications that pertain to different vertical industries. Delivering on the key commitment of 5G, these diverse service streams, along with their distinct requirements, should be facilitated under the same unified network infrastructure. Consequently, in order to unleash the benefits brought by 5G technology, a holistic approach towards the requirement analysis and the design, development, and evaluation of multiple concurrent vertical services should be followed. In this paper, we focus on the Transport vertical industry, and we study four novel vehicular service categories, each one consisting of one or more related specific scenarios, within the framework of the “5G Health, Aquaculture and Transport (5G-HEART)” 5G PPP ICT-19 (Phase 3) project. In contrast to the majority of the literature, we provide a holistic overview of the overall life-cycle management required for the realization of the examined vehicular use cases. This comprises the definition and analysis of the network Key Performance Indicators (KPIs) resulting from high-level user requirements and their interpretation in terms of the underlying network infrastructure tasked with meeting their conflicting or converging needs. Our approach is complemented by the experimental investigation of the real unified 5G pilot’s characteristics that enable the delivery of the considered vehicular services and the initial trialling results that verify the effectiveness and feasibility of the presented theoretical analysis

Modeling and analysis of smart malicious software propagation techniques using topological properties of dynamic and Ad-Hoc large scale networks

The propagation of malicious software (malware) has become one of the major issues in contemporary networking infrastructures, emerging at various levels and occasions. Significant work for studying malware spreading has been performed, dealing mainly with wired networks which constitute the most significant part of today’s modern infrastructures. However, as the penetration of wireless ad hoc and sensor networks increases, the interest for corresponding studies in wireless networks increases as well. This thesis focuses on the study of malware propagation in large scale wireless ad hoc and sensor networks, emphasizing on the impact of network topology on the outcome of malware spreading in various types of networks. A novel framework that is based on the theory of closed queuing networks is proposed for describing the malware spreading process. The proposed model is made explicit for the case of ad hoc and sensor networks, leading to analytical expressions for the expected number of infected nodes and the expected total node infection rate in the network. Such time- independent metrics, combined with a proposed time-dependent one, namely Infection Efficiency, are used for evaluating malware propagation under different attack strategies and different types of network. More specifically, in order to analyze the impact of various attack strategies, malware propagation methods that are based on Topology Control are designed and analyzed. Such techniques exploit local topological network characteristics and available node resources for spreading malware more efficiently in wireless ad hoc networks. In the event that a specific malware module is desired to be propagated completely over a network, randomized spreading techniques that are based on Random Walks are proposed and compared in order to identify the most appropriate ones on a per network type case. Overall, through the analysis and study of the proposed framework for modeling malware propagation and the efficient malware spreading strategies, the importance of topology of a wireless ad hoc network becomes evident, as well as the means to exploit it from a malicious user point of view, or make the network more robust from an administrator’s perspective. Through the framework proposed in this thesis, the analysis and study of malware propagation by means of stochastic approaches and more specifically queuing theory seems promising for future extensions and further studies, especially as the frequency of such attacks keeps increasing, both in terms of quantity and intelligence. Similarly, power control and Topology Control respectively, appear to be appropriate methods for dealing with several emerging problems and consequently for more efficient protection of any-scale wireless ad hoc and sensor networks.Η διάδοση κακόβουλου λογισμικού έχει αναχθεί σε καίριο ζήτημα των σύγχρονων δικτυακών υποδομών κάνοντας την εμφάνισή του σε διάφορα επίπεδα. Σημαντική εργασία για την περιγραφή της διάδοσης έχει αφιερωθεί στη βιβλιογραφία για τις περιπτώσεις των ενσύρματων δικτύων που αποτελούν και το πιο μεγάλο τμήμα της τρέχουσας υποδομής, καθώς όμως αυξάνεται η διείσδυση των ασύρματων αυτοργανούμενων δικτύων, μεγαλώνει αντίστοιχα και το ενδιαφέρον για αυτές τις περιπτώσεις δικτύων. Η παρούσα εργασία επικεντρώνεται στη μελέτη της διάδοσης κακόβουλου λογισμικού σε ασύρματα αυτοργανούμενα δίκτυα ευρείας κλίμακας και εξετάζει την επίδραση της τοπολογίας στην εξέλιξη της διασποράς σε διάφορους τύπους δικτυών. Για το σκοπό αυτό προτείνεται ένα πρωτοποριακό μοντέλο περιγραφής της διάδοσης κακόβουλου λογισμικού, το οποίο βασίζεται στη θεωρία κλειστών δικτύων ουρών αναμονής. Το προτεινόμενο μοντέλο συγκεκριμενοποιείται για την περίπτωση ασύρματων αυτοργανούμενων δικτύων επιτρέποντας την εξαγωγή αναλυτικών αποτελεσμάτων για τον αναμενόμενο αριθμό μολυσμένων κόμβων στο δίκτυο και τον αναμενόμενο συνολικό ρυθμό μόλυνσης κόμβων. Τέτοια χρονικά-ανεξάρτητα μετρικά αξιολόγησης σε συνδυασμό με το χρονικά-εξαρτώμενο μετρικό της Αποδοτικότητας Μόλυνσης που εισάγεται, χρησιμοποιούνται για την αξιολόγηση της επίδοσης υπό διάφορες στρατηγικές διάδοσης και διαφορετικούς τύπους δικτύων. Με σκοπό τη μελέτη της επίδρασης διαφόρων στρατηγικών διασποράς κακόβουλου λογισμικού, ώστε να διαφανούν υποσχόμενες κατευθύνσεις για τη σχεδίαση αποδοτικών αντίμετρων, εισάγονται και αναλύονται έξυπνες στρατηγικές επίθεσης που στηρίζονται στον Έλεγχο Τοπολογίας και εκμεταλλεύονται κατάλληλα τα τοπικά τοπολογικά χαρακτηριστικά ενός δικτύου και τους διαθέσιμους πόρους κάθε κόμβου για την αποδοτικότερη διασπορά απειλών σε ασύρματα αυτοργανούμενα δίκτυα. Για τις περιπτώσεις όπου ένα συγκεκριμένο τμήμα κακόβουλου λογισμικού επιχειρείται να διαδοθεί καθολικά σε ένα δίκτυο, εισάγονται και αναλύονται τυχαιοποιημένες τεχνικές διασποράς ιών υπολογιστών που βασίζονται σε Τυχαίους Περίπατους. Συνολικά από την ανάλυση και μελέτη του γενικού πλαισίου για τη μοντελοποίηση της διάδοσης κακόβουλου λογισμικού και των αποδοτικών τεχνικών διασποράς, γίνεται φανερή η σημασία που έχει η τοπολογία ενός αυτοργανούμενου δικτύου σε τοπική κλίμακα και ο τρόπος που μπορεί αυτό να γίνει αντικείμενο εκμετάλλευσης από κακόβουλους χρήστες για να αυξήσουν την αποδοτικότητά τους, αλλά αντίστοιχα και από τους νόμιμους διαχειριστές των εν λόγω δικτύων για να θωρακίσουν περαιτέρω τις υποδομές τους. Μέσα από το πλαίσιο που παρουσιάζεται στην παρούσα διατριβή, η περιγραφή και ανάλυση της διάδοσης κακόβουλου λογισμικού με στοχαστικές μεθόδους φαίνεται αρκετά αποδοτική και πολλά υποσχόμενη για το μέλλον, ειδικότερα υπό το πρίσμα της αύξησης των επιθέσεων σε όγκο και ευφυΐα που αναμένεται καθώς αυξάνονται οι αντίστοιχες υποδομές. Αντίστοιχα, ο έλεγχος ισχύος υπό την έκφανση του Ελέγχου Τοπολογίας εμφανίζεται ως μια κατάλληλη μέθοδος για την αντιμετώπιση πολλών προβλημάτων και τελικά την αποδοτικότερη προστασία αυτοργανούμενων δικτύων ευρείας ή μικρότερης κλίμακας

Markov-Based Malware Propagation Modeling and Analysis in Multi-Layer Networks

In this paper, we focus on the dynamics of the spread of malicious software (malware) in multi-layer networks of various types, e.g., cyber-physical systems. Recurring malware has been one of the major challenges in modern networks, and significant research and development has been dedicated to mitigating it. The majority of relevant works has focused on networks characterized by “flat” topologies, namely topologies in which all nodes consist of a single layer, studying the dynamics of propagation of a specific threat or various types of malware over a homogeneous topology. As cyber-physical systems and multi-layer networks in general are gaining in popularity and penetration, more targeted studies are needed. In this work, we focus on the propagation dynamics of recurring malware, namely Susceptible–Infected–Susceptible (SIS type) in multi-layer topologies consisting of combinations of two different types of networks, e.g., a small-world overlaying a random geometric, or other such combinations. We utilize a stochastic modeling framework based on Markov Random Fields for analyzing the propagation dynamics of malware over such networks. Through analysis and simulation, we discover the most vulnerable and the most robust topology among the six considered combinations, as well as a result of rather practical use, namely that the denser the network, the more flexibility it provides for malware mitigation eventually

On the Potential of Enhancing Delay-Tolerant Routing Protocols via Age of Information

In this paper, we study the potential of using the metric of Age of Information (AoI) for enhancing delay-tolerant routing protocols. The latter have been proposed for alleviating the impact of long roundtrip time in networks operating in harsh environments, e.g., in distributed applications deployed in a desert/sparsely populated area without infrastructure, a space network, etc. Delay-tolerant routing protocols can prevent excessive packet timer expiration, but do not provide any packet delivery time guarantee. Thus, they are unsuitable for time-sensitive applications that are more intensely desired nowadays in the next generation networking applications. By incorporating AoI into the operation of delay-tolerant routing protocols, we aim at devising routing protocols that can cope with both long propagation times and challenges related to time-sensitivity in packet delivery. More specifically, in this work, we modify the operation of a well-known delay-tolerant routing protocol, namely FRESH, to make AoI-based packet forwarding decisions, aiming at achieving specific delay guarantees regarding the end-to-end delivery time. We investigate the advantages and disadvantages of such an approach compared to the traditional FRESH protocol. This work serves as a cornerstone for successfully demonstrating the potential of exploiting AoI in delay-tolerant routing and its applications