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The objective of the project was to develop models and methods suitable for computer implementation. In particular, this work has been devoted to generation scheduling of a power system with a sizeable amount. of hydro energy. Optimal operation planning of hydrothermal power systems aims at minimizing incurred production costs while supplying customer de­mand. The planning horizon may vary from one day to several years and the associated planning problems are categorized as short term, seasonal and long term operation planning. The topic of this thesis is short term operation planning. In this planning, it is necessary to use detailed models of the different parts of the power system. These include models of cas­caded reservoirs in a multi-river system as we11 as a representa­tion of the nonlinear generating characteristics of the hydro plants. he thermal generating units are modelled using linear production cost curves and by recognizing various technical constraints asso­ciated with the operation of these plants. Effects on the optimal operating strategy caused by interregional transmission capacity limitations are also accounted for by the model. These constraints are modelled to main1y affect the hydro plant operation. / <p>QC 20161207</p>

This thesis describes the Flexible Internetwork Stack (FINS) Framework, an open-source tool to facilitate experimental research in wireless networks on multiple platforms. The FINS Framework uses a module-based architecture that allows cross-layer behavior and runtime reconfiguration of the protocol stack. Version 1.0 of the framework makes use of existing physical and data link layer functionality, while enabling modifications to the stack at the network layer and above, or even the implementation of a clean-slate, non-layered protocol architecture. Protocols, stubs for communicating with intact layers, and management and supervisory functions are implemented as FINS Framework modules, interconnected by a central switch. This thesis describes the FINS Framework architecture, presents an initial assessment along with experiments on Android and Ubuntu enabled by the tool, and documents an intuitive mechanism for transparently intercepting socket calls that maintains efficiency and flexibility. / Master of Science

Network programming is one of the most important applications in Wireless Sensor Networks as It provides an efficient way to update program Images running on sensor nodes without physical access to them. Securing these updates, however, remains a challenging and important issue, given the open deployment environment of sensor nodes. Though several security schemes have been proposed to impose the authenticity and Integrity protection on network programming applications, they are either energy Inefficient as they tend to use digital signature or lacks the data confidentiality. In addition, due to the absence of secure memory management in the current sensor hardware, the attacker could inject malicious code into the program flash by exploiting buffer overflow In the memory despite the secure code dissemination. The contribution of this thesis Is to provide two software-based security protocols and one hardware-based remote attestation protocol for network programming application. Our first protocol deploys multiple one-way key chains for a multi-hop sensor network. The scheme Is shown to be lower In computational, power consumption and communication costs yet still able to secure multi??hop propagation of program images. Our second protocol utilizes an Iterative hash structure to the data packets in network programming application, ensuring the data confidentiality and authenticity. In addition, we Integrated confidentiality and DoS-attack-resistance in a multi??hop code dissemination protocol. Our final solution is a hardware-based remote attestation protocol for verification of running codes on sensor nodes. An additional piece of tamper-proof hardware, Trusted Platform Module (TPM), is imposed into the sensor nodes. It secures the sensitive information (e.g., the session key) from attackers and monitors any platform environment changes with the Internal registers. With these features of TPM, the code Injection attack could be detected and removed when the contaminated nodes are challenged in our remote attestation protocol. We implement the first two software-based protocols with Deluge as the reference network programming protocol in TinyOS, evaluate them with the extensive simulation using TOSSIM and validate the simulation results with experiments using Tmote. We implement the remote attestation protocol on Fleck, a sensor platform developed by CSIRO that Integrates an Atmel TPM chip.

Network programming is one of the most important applications in Wireless Sensor Networks as It provides an efficient way to update program Images running on sensor nodes without physical access to them. Securing these updates, however, remains a challenging and important issue, given the open deployment environment of sensor nodes. Though several security schemes have been proposed to impose the authenticity and Integrity protection on network programming applications, they are either energy Inefficient as they tend to use digital signature or lacks the data confidentiality. In addition, due to the absence of secure memory management in the current sensor hardware, the attacker could inject malicious code into the program flash by exploiting buffer overflow In the memory despite the secure code dissemination. The contribution of this thesis Is to provide two software-based security protocols and one hardware-based remote attestation protocol for network programming application. Our first protocol deploys multiple one-way key chains for a multi-hop sensor network. The scheme Is shown to be lower In computational, power consumption and communication costs yet still able to secure multi??hop propagation of program images. Our second protocol utilizes an Iterative hash structure to the data packets in network programming application, ensuring the data confidentiality and authenticity. In addition, we Integrated confidentiality and DoS-attack-resistance in a multi??hop code dissemination protocol. Our final solution is a hardware-based remote attestation protocol for verification of running codes on sensor nodes. An additional piece of tamper-proof hardware, Trusted Platform Module (TPM), is imposed into the sensor nodes. It secures the sensitive information (e.g., the session key) from attackers and monitors any platform environment changes with the Internal registers. With these features of TPM, the code Injection attack could be detected and removed when the contaminated nodes are challenged in our remote attestation protocol. We implement the first two software-based protocols with Deluge as the reference network programming protocol in TinyOS, evaluate them with the extensive simulation using TOSSIM and validate the simulation results with experiments using Tmote. We implement the remote attestation protocol on Fleck, a sensor platform developed by CSIRO that Integrates an Atmel TPM chip.

The main aim of this master's thesis is to implement a common, secure and peer-to-peer communication system. The system has ability to automatically establish and run a secure end-to-end connection. It has this ability even if a network address translator is in the way to the destination system, without need of any explicit configuration of this translator. The security procedures of this system are in a transparent manner masked from individual applications, which had to solve this challenge in their own way. A responsibility for a security is delegate to an application-independent subsystem working within the core of an operating system. The security of this subsystem is based on capturing the outbound and inbound IP packets and their authentication and encryption. The system was successfully implemented in MS Windows XP operating system, in programming language C++. Transfer rate of communication tunnel in different network bandwidth speeds was measured. Result shows, that in the case of use the system on standard PC sold nowadays is practically no decrease of the transfer rate in comparison to a common channel.

Τα ασύρματα δίκτυα αισθητήρων αποτελούν μία πρωτοποριακή τεχνολογία που ήρθε στο προσκήνιο πριν από μία περίπου δεκαετία. Η καινοτομία της τεχνολογίας αυτής έγκειται στη συνεργασία μεγάλου αριθμού κόμβων περιορισμένων πόρων χαμηλής κατανάλωσης ισχύος σε μία μόνο εφαρμογή. Η εργασία αυτή ασχολείται με θέματα ενδιάμεσου λογισμικού σε ασύρματα δίκτυα αισθητήρων. Συγκεκριμένα, μελετάται το πρωτόκολλο Deluge που αποτελεί τη βασική επιλογή για ασύρματο προγραμματισμό δικτύων αισθητήρων που «τρέχουν» το λειτουργικό σύστημα πραγματικού χρόνου TinyOS. Παρέχοντας έναν αξιόπιστο και αποδοτικό μηχανισμό διάδοσης δεδομένων μέσω της δυαδικής εικόνας του κώδικα, το Deluge κατέχει ρόλο-κλειδί στη βαθμίδα ενδιάμεσου λογισμικού των ασύρματων δικτύων αισθητήρων. Η μελέτη και κατανόηση του πρωτοκόλλου αυτού επέτρεψε την υλοποίηση σε nesC ενός απλούστερου πρωτοκόλλου που αξιοποιεί τα βασικά χαρακτηριστικά του μηχανισμού μετάδοσης δεδομένων του Deluge. Σε συνέχεια αυτής της υλοποίησης, αξιολογήθηκε εκ νέου η διαδικασία μετάδοσης πραγματοποιώντας δοκιμές τόσο σε πραγματικές τοπολογίες κόμβων αισθητήρων (motes) που υποστηρίζουν το πρότυπο ασύρματης επικοινωνίας IEEE 802.15.4 όσο και σε περιβάλλον προσομοίωσης (TOSSIM). Τα προκύπτοντα αποτελέσματα επιβεβαιώνουν την αποδοτική μετάδοση δεδομένων σε δίκτυα αισθητήρων αξιοποιώντας το πρωτόκολλο Deluge. Η παρούσα εργασία αποτελείται από έξι κεφάλαια. Το πρώτο κεφάλαιο παρέχει πληροφορίες για το γνωστικό αντικείμενο της εργασίας. Στο δεύτερο κεφάλαιο παρουσιάζεται μία μελέτη στην ερευνητική περιοχή των ασύρματων δικτύων αισθητήρων και στο τρίτο κεφάλαιο εξετάζονται τα βασικά χαρακτηριστικά ενός κόμβου αισθητήρων που υποστηρίζει το πρότυπο IEEE 802.15.4. Στο τέταρτο κεφάλαιο παρουσιάζεται η έννοια του ασύρματου προγραμματισμού στα δίκτυα αισθητήρων και μελετάται εκτενώς το πρωτόκολλο Deluge. Στο πέμπτο κεφάλαιο περιγράφεται η υλοποίηση που έλαβε χώρα και η αξιολόγηση αυτής με τους μηχανισμούς που αναφέρθηκαν παραπάνω. Τέλος, στο έκτο κεφάλαιο παρατίθενται τα συμπεράσματα που εξήχθησαν από την εκπόνηση της εν λόγω εργασίας και δίνονται ορισμένες κατευθύνσεις για μελλοντική ενασχόληση με το Deluge και με το ενδιάμεσο λογισμικό στα δίκτυα αισθητήρων γενικότερα. / Wireless sensor networks (WSNs) emerged about a decade ago, representing a new class of computing with large numbers of resource-constrained computing nodes cooperating on a single application. This thesis deals with middleware issues in wireless sensor networks. Specifically, we study Deluge that suggests the de facto over-the-air programming protocol for WSNs working under TinyOS. Providing a reliable and efficient data dissemination mechanism via the binary image of the program code, Deluge plays a key role in the middleware layer of WSNs. Gaining insight into Deluge, we implemented in the nesC programming language a simplified protocol that incorporates the main features of Deluge data dissemination mechanism. This implementation allowed us to evaluate further the propagation procedure of Deluge using a two-mechanism evaluation framework. Carrying out experiments both in real-world deployments being compatible with IEEE 802.15.4 radio and in a simulation environment (TOSSIM), we verified the efficient data propagation in WSNs, using Deluge. This dissertation follows a structure of six chapters. In the first chapter, we give a piece of information about the subject field of this thesis. In the second chapter, we present an overall survey of the research area of WSNs and in the third chapter we examine the basic features of a sensor node (mote) whose wireless communication is based on an IEEE 802.15.4 compliant radio. In the fourth chapter, we discuss network programming in WSNs and we analyze the data dissemination mechanism of Deluge. In the fifth chapter, we discuss our implementation and its evaluation. Finally, in the sixth chapter, we conclude the thesis emphasizing the experience derived from that and we give some directions for future work with Deluge and middleware in WSNs generally.