Hyper-V

Hepatitis C virus (HCV) is a member of the family Flaviviridae, and the principal cause of parenteral non A non B hepatitis. HCV is a single stranded, positive sense RNA virus whose genome contains a single open reading frame of about 10 kb in length which encodes a polyprotein of about 3000 amino acids. HCV is responsible for majority of the transfusion associated cases of hepatitis and a significant proportion of community-acquired hepatitis which leads to a range of clinical manifestations from an apparent carrier state to severe chronic hepatitis, liver cirrhosis and hepatocellular carcinoma. Cell-free translation and cell culture transient expression studies revealed that HCV genome initially transcribed as a polyprotein is processed by cellular and viral proteases to produce the putative viral structural and nonstructural proteins. The preliminary map of the gene order for HCV was established: 5' untranslated region (UTR)-core (C)-envelope 1 (E1)-E2nonstructural 2(NS2)-NS3-NS4A-NS4B-NS5A-NS5B-UTR3'. Nonstructural proteins, NS2, NS3 and NS5, are believed to be a component of viral coded enzymes. Mutations in hypervariable region 1 (HVR1) of the E2 protein was considered to be a possible mechanism of chronicity of HCV infection. HCV infection can be monitored either by serodiagnosis or by genodiagnosis. Interferon seems to be considered as the sole drug for HCV treatment until now.In the history of virology, HCV was the first example that was identified by molecular cloning of its genome from infectious materials.

This research paper investigates the effectiveness of centralized control systems for managing multiple end-user computers from a single hub. Through qualitative analysis involving eight participants with diverse technical backgrounds, the study evaluates productivity differences between using no centralized remote access system versus implementing solutions such as Windows Server, TeamViewer, Microsoft Quick Assist, and Hyper-V. Using a within-subjects design, participants completed identical tasks across all five conditions while researchers collected data through semi-structured interviews, think-aloud protocols, observation notes, and task completion reflections. Results demonstrate significant productivity improvements with centralized management tools, with Windows Server Remote Access yielding the highest productivity score (13/15), representing a 333% improvement over the baseline condition (3/15). The paper examines how centralized systems reduce downtime through real-time troubleshooting, create consistent user experiences, enhance security compliance, and support remote work capabilities. The methodology employs thematic analysis following Braun and Clarke's sixphase approach to identify key productivity factors. This research contributes valuable insights for organizations seeking to optimize IT resource management, improve support efficiency, and enhance end-user productivity through centralized control solutions.

Use of virtualization in datacenter or service providers or even in cloud computing environments brings many benefits. Virtualization, whether it is for services, applications or servers, is no longer a trend to be a reality in many industries and areas, whether in or outside the technology area. Therefore, with this emergent use of virtualization companies have been asking a lot about the performance and security of using virtual machines in a highly availability infrastructures. Controlling the access to Virtual Machines is a security issues that all the hypervisors haves, such as, VMware vSphere, Hyper-V or KVM. To make virtual machines more secure Microsoft has introduced the concept of Shielded virtual machines. Taking this into account, this dissertation presents a study on key concepts behind virtual machines, Guarded Fabric, Host Guardian Service, Guarded Hosts and shielded virtual machines. A Shielded VM is a Generation 2 feature (supported on Windows Server 2012 and later) that comes with a virtual Trusted Platform Module (TPM), which can only run on healthy and approved hosts in the fabric and is encrypted using BitLocker. In order to support our study an experimental bed test has been setup, involving a failover cluster with native virtualization at the hardware level with Windows Server 2016 Hyper-V. In the test environment, a failover clustering, FreeNAS Storage, ISCSI Target, VMs, Guarded Fabric and Shielded virtual machines have been implemented and configured. After the implementation of the bed test, a set of tests and experiments haves been made in order to study the performance implications for the use of virtual machines versus shielded virtual machine in High Availability Virtualized Infrastructures. Finally, an analysis at the results worked through the tests has been made, according to the Background made in the first part and the bed test deployed. A set of experiments has been made in virtual machines and shielded virtual machines in order to evaluate its performance in terms of CPU, RAM and writing speed. The results show that the use of shielded virtual machines leads to a small degradation of performance compared to the use of regular virtual machines, but, on the other hand, it has also been shown that the shielded virtual machines allows to restrict access to the virtual machines only for run on trusted hosts, and prevent unauthorized administrators and malwares from compromising the virtual machine.

Faults in Web APIs may escape the testing process, and therefore affect thousands of Web applications. As a consequence, users of these applications might suffer from related failures for a long time until proper fixes are released by the Web API developers. In this paper we present RAW, a tool that tries to find workarounds automatically and at runtime, thereby

Σχεδίαση του Αρχικού Διαγράμματος Κλάσεων 6.2.4 Συμπερίληψη Κλάσεων Διεπιφάνειας Χρήσης 6.2.5 Συμπερίληψη των Προτύπων Ασφάλειας με Βάση τις Κακές Περιπτώσεις Χρήσης 6.3 Ανταγωνισμός (Trade-off) μεταξύ Κινδύνου και Προσπάθειας Ανάπτυξης για το Σύστημα 6.4 Ένα Πρόβλημα Βελτιστοποίησης Βασισμένο στον Κίνδυνο και την Απαιτούμενη Προσπάθεια 7. Συμπεράσματα 8. Μελλοντική Έρευνα Αναφορές Παράρτημα I. Απόδοση Ξένων Όρων στα Ελληνικά Παράρτημα ΙΙ. Υπολογισμος του κινδύνου και της ομοιότητας με λεκτικούς όρους για ένα δένδρο σφαλμάτων

Cloud computing is the long dreamed vision of computing as a utility, where data owners can remotely store their data in the cloud to enjoy on-demand high-quality applications and services from a shared pool of configurable computing resources. In the meantime, the cloud environment represents various difficulties. Two players in distributed computing situations, cloud suppliers and cloud clients, seek after diverse objectives; suppliers need to amplify income by accomplishing high asset usage, while clients need to minimize costs while meeting their execution prerequisites. Nonetheless, it is hard to allot resources in a commonly ideal manner because of the absence of data sharing between them. In addition, continually expanding heterogeneity and variability of the surroundings poses considerably harder difficulties for both sides. This paper describes the work which mainly aimed at enhancing the load balancing architecture where firstly genetic algorithm is been implemented with simple architecture [1]. Secondly, genetic algorithm is been implemented with enhanced architecture named as E-GA where job grouping is done according to job's requirements. Finally the whole architecture is been enhanced by using job grouping method with enhanced genetic algorithm

This dissertation for a bachelor project in computer science at Karlstad University will describe how to conquer a challenge suggested by Tieto: How to create a secure Incident Reporting System with a high level of confidentiality and security for the contents. The system should be easy to use and encourage incident reporting, open for changes and statistics gathering, for those with the relevant authority. The result will be a requirement specification and a prototype incident management system that matches those requirements. Any employee of Tieto will be able to submit an incident report and the system will notify a security administrator at Tieto who will solve the problem. The system will be able to gather information and statistics regarding incidents which can be used as decision support.

The need for cost optimization in a broad sense constitutes the basis of operation of every enterprise. In the case of IT structure (which is present in almost every field of activity these days), one of the most commonly applied technologies leading to good cost-to-profit adjustment is virtualization. This allows the location of several operational systems with IT systems on a single server. In order for such an optimization to be carried out correctly, it has to be strictly controlled by means of allocating access to resources (which is known as performance isolation). Modern virtualizers allow us to set up this allocation in quantitative terms (the number of processors, size of RAM, or disc space). It appears, however, that in qualitative terms (processor time, RAM, or hard disc bandwidth), the actual allocation of resources does not always correspond with this configuration. This paper provides an experimental presentation of the achievable quality level of performance isolation of the Hyper-V virtualizer.

Το παρόν σύγγραμμα έρχεται να υπηρετήσει τη διδασκαλία του μαθήματος «Εισαγωγή στις Αρχές της Επιστήμης των Η/Υ», προσεγγίζοντας θέματα τόσο της Θεωρητικής όσο και της Εφαρμοσμένης Επιστήμης των Η/Υ. Το πρώτο μέρος καλύπτει θέματα της Θεωρητικής Επιστήμης των Υπολογιστών –από το Πρόβλημα στον Αλγόριθμο και από εκεί στον Προγραμματισμό και τις Εφαρμογές του– μέσω του οποίου επιδιώκεται η ανάπτυξη της αναλυτικής και συνθετικής σκέψης των μαθητών και των μαθητριών. Στο δεύτερο μέρος, το βιβλίο πραγματεύεται ζητήματα των βασικών τομέων της Εφαρμοσμένης Επιστήμης των Υπολογιστών, ώστε να βοηθήσει τους μαθητές και τις μαθήτριες να είναι σε θέση να κατονομάζουν και να εξηγούν επιστημονικές περιοχές της Πληροφορικής. Αναλυτικότερα, στην πρώτη ενότητα, στο Κεφάλαιο 1.1 επιχειρείται η διάκριση της Επιστήμης των Η/Υ σε Θεωρητική και Εφαρμοσμένη. Η παραπάνω διάκριση διαχωρίζει το σύγγραμμα σε δύο ακόμα ενότητες. Στη δεύτερη ενότητα και στο Κεφάλαιο 2.1 επαναπροσεγγίζεται η έννοια του προβλήματος και οι φάσεις επίλυσής του και αναδεικνύονται τα υπολογιστικά προβλήματα. Στη συνέχεια, στο Κεφάλαιο 2.2 περιγράφεται η έννοια του αλγορίθμου και των χαρακτηριστικών του, προσδιορίζονται οι διάφορες μορφές αναπαράστασής του και επεξηγούνται οι βασικές έννοιες στην Ανάλυση Αλγορίθμων. Ακολούθως, αναφέρονται οι βασικοί τύποι και οι δομές δεδομένων καθώς και οι βασικές εντολές και δομές που χρησιμοποιούνται σε έναν αλγόριθμο. Τέλος, στο κεφάλαιο αυτό, προσδιορίζεται ο τρόπος εντοπισμού και διόρθωσης λογικών λαθών σε έναν αλγόριθμο. Όλα τα παραπάνω βήματα, αποτελούν τα στάδια προετοιμασίας των μαθητών και μαθητριών, ώστε στο Κεφάλαιο 2.3 να προχωρήσουν στη δημιουργία ενός γνωσιακού και νοητικού σχήματος που να περιλαμβάνει τα είδη και τις τεχνικές προγραμματισμού και συγχρόνως να είναι σε θέση να συνδυάζουν τις αλγοριθμικές δομές, τα δεδομένα και τις δομές δεδομένων για να δημιουργήσουν προγράμματα. Τέλος, στην ενότητα αυτή αναδεικνύεται ότι οι σημερινές εφαρμογές είναι αρκετά πολύπλοκες και η δημιουργία τους ακολουθεί συγκεκριμένα μοντέλα ανάπτυξης εφαρμογών λογισμικού που εξελίσσονται σε φάσεις. Η τρίτη ενότητα ασχολείται με θέματα της Εφαρμοσμένης Επιστήμης των Υπολογιστών, η οποία εστιάζει τόσο στην επίλυση προβλημάτων, όσο και στη βελτίωση υπαρχουσών λύσεων στον πραγματικό κόσμο. Σε όλους τους τομείς της καθημερινότητας υπάρχει ένας τεράστιος όγκος διαθέσιμης πληροφορίας και γνώσεων, η διαχείριση του οποίου προϋποθέτει τις κατάλληλες υπολογιστικές υποδομές για την αποθήκευση της πληροφορίας καθώς και το σχεδιασμό, την ανάπτυξη και τη συντήρηση λογισμικού μέσω κατάλληλων γλωσσών προγραμματισμού και συστημάτων λογισμικού, τα οποία συνεργάζονται με την υπολογιστική υποδομή. Τέλος, προϋποθέτει την υποδομή μέσω των οποίων οι πληροφορίες διακινούνται με ασφάλεια. Από τους βασικούς τομείς της Εφαρμοσμένης Επιστήμης των Υπολογιστών που έχουν σκοπό τη διερεύνηση και την κάλυψη των προαναφερθεισών αναγκών, έχουν επιλεγεί τέσσερις. Στο Κεφάλαιο 3.1 περιγράφονται τα Λειτουργικά Συστήματα, δηλαδή το λογισμικό που συντονίζει το υλικό και επικοινωνεί με το χρήστη. Στη συνέχεια, στο Κεφάλαιο 3.2 επεξηγούνται τα Πληροφοριακά Συστήματα, μέσω των οποίων επιτελείται συλλογή, ανάκτηση, επεξεργασία και αποθήκευση πληροφοριών. Ακολούθως, στο Κεφάλαιο 3.3 επιχειρείται επισκόπηση των Δικτύων Υπολογιστών για τη λήψη και την προώθηση πληροφοριών και, τέλος, στο Κεφάλαιο 3.4 περιγράφεται η Τεχνητή Νοημοσύνη, η οποία ερευνά τρόπους ανάπτυξης υπολογιστικών μοντέλων ανθρώπινης γνώσης.

Τι είναι το TCP Header και ποια η σημασία του TTL στο IPv4 Header; Ποιο είναι το μέγιστο TTL; Διαφέρει ανά λειτουργικό σύστημα το TTL; Τι είναι το fragment; Για να αναλύσουμε την σημασία της επικεφαλίδας του tcp θα πρέπει πρώτα να πούμε δυο λογία για το tcp πρωτόκολλο. Το οποίο είναι το πρωτόκολλο το οποίο είναι στο στρώμα (επίπεδο) της μεταφοράς στο πρωτόκολλο ISO/OSI (μαζί με το udp). To TCP παρέχει μια σύνδεση με προσανατολισμό την υπηρεσία, και εγγυάται την παράδοση όλων πακέτα επίπεδο εφαρμογών στον προορισμό τους. Ενώ το TCP παρέχει εγγυήσεις παράδοσης του στρώματος εφαρμογής πακέτα, UDP, από την άλλη πλευρά, δεν προσφέρει τέτοιες εγγυήσεις. Το TCP header αποτελείτε από τα έξεις : Το πιο πάνω σχήμα είναι το tcp/ip header.

Disaster recovery is a persistent problem in IT platforms. This problem is more crucial in cloud computing, because Cloud Service Providers (CSPs) have to provide the services to their customers even if the data center is down, due to a disaster. In the past few years, researchers have shown interest to disaster recovery using cloud computing, and a considerable amount of literature has been published in this area. However, to the best of our knowledge, there is a lack of precise survey for detailed analysis of cloud-based disaster recovery. To fill this gap, this paper provides an extensive survey of disaster recovery concepts and research in the cloud environments. We present different taxonomy of disaster recovery mechanisms, main challenges and proposed solutions. We also describe the cloud-based disaster recovery platforms and identify open issues related to disaster recovery.

The integration of software solutions in the content of training courses resulted from the socioeconomic demand, has a positive effect on the enhancement of trainee students for future professional activities. However, the latest achievements of hardware and software are still not included in the content of the higher education in a timely manner. Therefore, we focused in our research on the improvement of the content of the training course based on a client-server technology by using modern software capabilities. The article presents the conceptual structure of the training course, settings and the integration of local and public cloud-based servers. It describes approaches of its use in the learning process. Microsoft SQL Server 2016, Microsoft Azure SQL Database, ASP.NET MVC 5 Framework were used for teaching environments. The new course was introduced for Computer Science students of

In order to improve service execution in Clouds, the management of Cloud Infrastructure has to take measures to adhere to Service Level Agreements and Business Level Objectives, from the application layer through to how services are supported at the lowest hardware levels. In this paper a risk model methodology and holistic management approach is developed specific to the operation of the Cloud Infrastructure Provider and is applied through improvements to SLA fault tolerance in Cloud Infrastructure. Risk assessments are used to analyse execution specific data from the Cloud Infrastructure and linked to a business driven holistic management component that is part of a Cloud Manager. Initial results show improved ecoefficiency, virtual machine availability and reductions in SLA failure across the whole Cloud infrastructure by applying our combined risk-based fault tolerance approach.

Στις παρακάτω σημειώσεις παρουσιάζεται η δημιουργία γραφικού περιβάλλοντος χρήστη GUI στην Python. Για την δημιουργία GUI θα χρησιμοποιηθεί η default βιβλιοθήκη της python η οποία είναι η Tkinter η οποία δημιουργεί το γραφικό περιβάλλον χρήστη.

Το Κίνημα Ελεύθερου Λογισμικού έχει ως βασικό στόχο την υπεράσπιση της ελευθερίας των χρηστών υπολογιστικών συστημάτων. Αυτή η εργασία εξετάζει το Κίνημα Ελεύθερου Λογισμικού στο θεωρητικό πλαίσιο της συγκρουσιακής πολιτικής και των κοινωνικών κινημάτων.
Σεμιναριακή εργασία (χειμερινό εξάμηνο 2017-2018).

SQL Server 2014 delivers mission critical performance across all workloads with in-memory built-in, faster insights from any data with familiar tools, and a platform for hybrid cloud enabling organizations to easily build, deploy, and manage solutions that span on-premises and cloud.

Η παρούσα εργασία έγινε στο πλαίσια της ενότητας "Πληροφορική - Πολυμέσα". Με αφορμή το κεφ. 9 με τίτλο “Εικονική πραγματικότητα” στο Μουστάκας, Κ., Παλιόκας, Ι., Τζοβάρας, Δ., Τσακίρης “Γραφικά και εικονική πραγματικότητα” και αφορά την εισαγωγή στην έννοια της εικονικής πραγματικότητας.

Techlabs is a network the authors implemented some years ago in order to provide a rich learning environment through the use of virtualisation. They outlined the background to and reasons for employing virtualisation in a paper to the conference of the National Advisory Committee on Computing Qualifications (NACCQ) in 2004. In this paper they now describe some of the changes they have introduced during the past four years, in the context of recent developments and the widespread adoption, both in industry and the academic sector, of virtualisation of one form or another.

H ανησυχητική αύξηση των απειλών που προέρχονται από το χώρο του διαδικτύου κατέστησε επιτακτική την ανάγκη ύπαρξης επαρκώς καταρτισμένου προσωπικού που θα μπορεί να τις αντιμετωπίσει. Στα παραπάνω πλαίσια, δημιουργήθηκε το project Hackademic, ένα εργαλείο που έχει ως στόχο να προσφέρει στους φοιτητές γνώση σχετική με τα εργαλεία και τις τεχνικές που χρησιμοποιούν οι επίδοξοι κυβερνοεγκληματίες. Στα πλαίσια της παρούσας εργαστηριακής αυτής άσκησης, θα γίνει μία παρουσίαση του εν λόγω εργαλείου, ενώ θα ζητηθεί από τους συμμετέχοντες να προβούν σε λύση των ασκήσεων που το εργαλείο αυτό περιλαμβάνει. Παράλληλα θα ζητηθεί από αυτούς να χωριστούν σε ομάδες και να καταγράψουν τα συναισθήματα που βίωσαν κατά τη διαδικασία επίλυσης των ασκήσεων.

Utilizing cloud computing services has had numerous advantages such as the reduction of costs, development of efficiency, central promotion of soft wares, compatibility of various formats, unlimited storage capacity, easy access to services at any time and from any location and, most importantly, the independency of these services from the hardware. It should be mentioned that the provision of various cloud computing services is faced with problems and challenges that the fault tolerance can be mentioned as the main restrictions. In this paper, first, methods of creating the capacity of Fault Tolerance in Cloud computing are pointed out. Subsequently, policies of the implementation of these methods are stated. Next, the offered archi-tectures for the production of such capacity in Cloud computing is delineated and, finally, they are compared in terms of the type of policy or policies employed in the architecture and the method of fault detection and fault recovery.

If you asked me to pick the killer feature of WS2012 Hyper-V, then Replica would be high if not at the top of my list (64 TB VHDX is right up there in the competition). In Ireland, and we're probably not all that different from everywhere else, the majority of companies are in the small/medium enterprise (SME) space and the vast majority of my customers work exclusively in this space. I've seen how DR is a challenge to enterprises and to the SMEs alike. It is expensive and it is difficult. Those are challenges an enterprise can overcome by spending, but that's not the case for the SME. Virtualisation should help. Hardware consolidation reduces the cost, but the cost of replication is still there. SAN's often need licenses to replicate. SAN's are normally outside of the reach of the SME and even the corporate regional/branch office. Software replication which is aimed at this space is not cheap either, and to be honest, some of them are more risky than the threat of disaster. And let's not forget the bandwidth that these two types of solution can require. Isn't DR Just An Enterprise Thing? So if virtualisation mobility and the encapsulation of a machine as a bunch of files can help, what can be done to make DR replication a possibility for the SME? Enter Replica (Hyper-V Replica), a built-in software based asynchronous replication mechanism that has been designed to solve these problems. This is what Microsoft envisioned for Replica: ◾ If you need to replicate dozens or hundreds of VMs then you should be using a SAN and SAN replication. Replica is not for the medium/enterprise sites.

A major challenge in the area of Computer Science is the confrontation and prevention of malicious threats that harm the computer systems. Those threats take the form of malicious software (malware), whichinfluences confidentiality, integrity and availability and sometimes altogether.
The Scientific Areas concerned withthe analysis confrontation and prevention of these threats belong to Network Security.  Since the beginning of the Internet as we know it malware have been the talk of the world.
In the context of this thesis:
• Research has been conducted regarding the types of malicious software and there has been a extensive analysis of each type.
• A historical recursion was made.
• The types of viral software were analyzedwith research that worked in the context of a virtual system (Sandboxes).
• A manual way of malicious software confrontation was analyzed.
• A new way of malicious software prevention was proposed.
• The weaknesses of the malicious software were reported.

With the advancement of technology, computing has0 changed in a very drastic way. It has travelled a very long way from parallel to distributed to grid computing. Now a-days, the most pre-dominant internet based computing is Cloud computing. This technology provides a large number of pros like on-demand access, ubiquitous network access, rapid elasticity etc. But like other technology, it suffers from some serious issues as well like workflow scheduling, security etc. Here, we are going to propose a model which is providing high fault tolerance to real time systems in cloud environment. The main feature of this proposed model is the adaptive behaviour of the reliability of each and every virtual machine along with addition and removal of nodes on the basis of reliability If a virtual machine produces correct result within time, then its reliability increases and if it fails to do so, then its reliability decreases as well. And also, priority scheduling has been introduced so as to determine the best node when the reliabilities of two nodes come out to be same.

The virtual machine (VM) migration brings multiple benefits such as higher performance, improved manageability and fault tolerance. Failures are often common in systems comprising thousands of processors and often we encounter these failures using a well defined Fault Tolerance Mechanism (FTM).This technique is enabled using a Virtual Machine (VM) migration policy. Managing the placement and migration of VMs in a data centre is a significant challenge. This paper presents an overview of Cloud and its Services, then Fault Tolerance is discussed in detail, giving review of VM Migration policies.

Fault Tolerance is concerned with all the techniques necessary to enable a system to tolerate faults remaining in the system after its development and often we encounter these failures using a well defined Fault Tolerance Mechanism(FTM).This technique is enabled using a Virtual Machine (VM) migration policy. This paper proposed a new method of identifying the need to migrate VM Machines, whenever there is an overload of work in the VM(s). The proposed algorithm provided with a way of computing the moving (dynamic) current thresholds as per current load of the data center calculated on the basis of effectiveness factor, which further provides us with implementation of a policy which remains refresh, since the payload of the datacenter varies during the day.

Techlabs is a network the authors implemented some years ago in order to provide a rich learning environment through the use of virtualisation. They outlined the background to and reasons for employing virtualisation in a paper to the conference of the National Advisory Committee on Computing Qualifications (NACCQ) in 2004. In this paper they now describe some of the changes they have introduced during the past four years, in the context of recent developments and the widespread adoption, both in industry and the academic sector, of virtualisation of one form or another.