<p>The ACTR (Asynchronous Communications Transmitter Receiver) is a serial data transfer link for the Data General ECLIPSE and NOVA minicomputer lines. The ACTR allows the interconnection of computers in the NOVA and ECLIPSE lines into a multiprocessor system by permitting blocks ot data to be transferred through the computers' program I/O tacitities. Such a small computer multiprocessor system is a powerful, high flexible alternative to a single large computer in many applications. The major application of the ACTR is in systems where the linked processors are either far remote from one another or where the system is so configured that a master/slave environment is practical.</p> <p>This report will deal with the theory of Operation of the hardware as well as the software control of the ACTR. A method of handling the ACTR in a multi-tasking environment under the Data General operating systems, RDOS/RTOS, will also be developed.</p> / Thesis / Master of Engineering (ME)

The total solar eclipse over the continental United States on August 21, 2017 offered a unique opportunity to study the dependence of the ionospheric density and morphology on incident solar radiation. Unique responses may be witnessed during eclipses, including changes in radio frequency (RF) propagation at high frequency (HF). Such changes in RF propagation were observed by the Super Dual Auroral Radar Network (SuperDARN) radars in Christmas Valley, Oregon and in Fort Hays, Kansas during the 2017 eclipse. At each site, the westward looking radar observed an increase in slant range of the backscattered signal during the eclipse onset followed by a decrease after totality. In order to investigate the underlying processes governing the ionospheric response to the eclipse, we employ the HF propagation toolbox (PHaRLAP), created by Dr. Manuel Cervera, to simulate SuperDARN data for different models of the eclipsed ionosphere. Thus, by invoking different hypotheses and comparing simulated results to SuperDARN measurements, we can study the underlying processes governing the ionosphere and improve our model of the ionospheric responses to an eclipse. This thesis presents three studies using this method: identification of the cause of the increase in slant range observed by SuperDARN during the eclipse; evaluation of different eclipse obscuration models; and quantification of the effect of the neutral wind velocity on the simulated eclipse data. / Master of Science / The ionosphere is the charged layer of the upper atmosphere, which is generated and sustained by sunlight ionizing neutral particles to form a plasma. In the absence of sunlight, ions and electrons can recombine into neutral particles. The total solar eclipse over the continental United States on August 21, 2017 offered a unique opportunity to study the dependence of the ionospheric density and plasma motion on sunlight as the period of the eclipse is much shorter than night. Observations of the ionosphere during past eclipses indicate that unique ionospheric behavior may be witnessed during eclipses, including changes in radio wave propagation for radio waves in the high frequency (HF) regime. Such changes in radio propagation were observed by the Super Dual Auroral Radar Network (SuperDARN) ionospheric HF radars in Christmas Valley, Oregon and in Fort Hays, Kansas during the 2017 eclipse. At each site, the westward looking radar observed an increase in distance that the radio waves traveled before they were reflected back to the radar during the eclipse onset followed by a decrease in this distance after totality. In order to investigate the mechanisms that produce these observed effects, we employed the HF propagation toolbox (PHaRLAP), created by Dr. Manuel Cervera, to simulate radio propagation and generate simulated SuperDARN data for different models of the eclipsed ionosphere. Thus, different models can be tested by comparing simulated data to measured data. Hence, we can study the underlying processes governing the ionosphere and improve our model of the ionospheric responses to an eclipse. This thesis presents three studies using this method to: identify the cause of the increase in the distance radio waves traveled during the eclipse; evaluate different models of change in eclipse magnitude over time; and investigate the effect of the neutral wind velocity on the simulated eclipse data.

Darbe nagrinėjama Eclipse programavimo aplinka. Aprašomos jos pagalbinė funkcijos pertvarkant darbinę aplinką bei kuriant Java projektus. Taip pat šias pagalbines funkcijas demonstruoja sukurta video medžiaga. Aprašomi SWT vaizdiniai komponentai. Supažindinama su Eclipse aplinkos papildiniu WindowBuilder. Sukurtų projektų pagalba pateikiamas SWT bei Swing vaizdinių komponentų skirtumas. Eclipse Micro Edition papildinio bei Sun Wireless Toolkit mobiliųjų prietaisų programinės įrangos pagalba pateikiami Midlet projektų kūrimo pavyzdžiai. Aprašomas darbo su MySQL duomenų baze projektas naudojant JDBC. / In this thesis we analyze Eclipse integrated development environment in customization and Java projects development contexts and illustrate our research with videos. We also describe graphical SWT components and WindowBuilder plug-in. Differences between SWT and Swing components are shown using specially created projects. Examples of Midlet projects, developed using Eclipse Micro Edition plug-in and Sun Wireless Toolkit for mobile device, are described. We also demonstrate connectivity to MySQL database through JDBC interface.

Paskirstytos maišos lentelės modeliai ir jų saugumo problemos yra aktyviai nagrinėjama sritis akademinėje bendruomenėje. Šiame darbe keliama hipotezė, kad praktinės DHT tinklų realizacijos neužtikrina teoriniuose modeliuose priimtos sąlygos, kad mazgų prisijungiančių prie tinklo identifikatoriai bus generuojami atsitiktinai. Randamas atakų sudėtingumo įvertis, kai atsitiktinių identifikatorių generavimas yra privalomas ir kai identifikatorius galima pasirinkti laisvai. Hipotezės patvirtinimui atliekamas eksperimentas. Surenkami ir analizuojami vieno didžiausių DHT tinklų (BitTorrent DHT) duomenys. Aprašomas literatūroje siūlomas problemos sprendimo būdas ir praktinės problemos kylančios jį realizuojant. Pasiūlomas naujas praktiškai pritaikomas ir našus identifikatorių generavimo patikrinimo metodas bei metodas naujų identifikatorių generavimo greičiui DHT tinkle valdyti. / Distributed Hash Table models and its security implications, has long been a subject of interest. This thesis is based on the assumption that practical implementations do not enforce random node id generation regardless of the fact that theoretical models require node ids to be chosen by random and distributed in the address space uniformly. To measure the impact on the DHT network security if the assumption holds an analysis of attack complexity in both cases is performed. Results indicate that the complexity grows from O(1) to O(M) if the node id cannot be selected arbitrarily (M is the number of nodes in DHT network). Stated assumption is confirmed by analysing classic node id protection methods and performing analysis of BitTorrent DHT network. The reason for the lack of node id protection in practice is considered to be the complexity and performance penalty of the classic methods. To facilitate the implementations of DHT networks a new method to ensure random node id generation and copy protection is provided. Proposed method utilizes MACs based on shared keys to provide a proof of the ownership of the node id while still providing means to protect it from being copied. Efficiency of the proposed method is evaluated by conducting an experiment. In order to protect small DHT networks against a Sybil attack a method to control the speed of node id generation is also proposed.

Idag så examineras tusentals studenter med stöd av duggor som finns i form av Quizar där premisserna är att elever fysiskt behöver genomföra examinationerna vid de olika lärosätena. I denna studie har projektet Quizer utarbetats med syftet att försöka förenkla och effektivisera digitala utvärderingar för inlärning och kontroll av kunskapsnivå. Den javabaserade webbapplikationen kan spara tid och resurser för lärarna att skapa, distribuera och betygsätta elevers kunskapsnivå med stöd av Quizar. Syftet med detta projekt har varit att förenkla och effektivisera metoden av examinering av studenter genom att implementera ett användbart Quiz verktyg där användarbasen och administrativa basen är helt oberoende av applikationsutvecklarens närvaro. För att planera projektet så har brainstorming, ER-diagram för planering av databasstruktur, flödesscheman för de olika vyerna i applikationen använts. Under planeringen har också olika ramverk undersökts för att fastställa vilka ramverk som passar bäst för just denna. Resultatet visar en javabaserad webbapplikation som underlättar examinering av studenter. Genomförandet av applikationen har med hjälp av Bootstrap nått sina mål under en viss tidsram. Resultatet visar även att metoden ger en tidsmässig vinst på ca 20 minuter i jämförelse till en tentamen under ordinarie former. Resultat utav användbarhetstesterna visar i helhet att applikationen har ett gränssnitt som är användarvänligt eftersom medelvärdet på ”upplevelse av applikationen” resulterade i 4, 25 utav 5 möjliga. Det har dessutom genomförts en jämförelse med existerande ramverk där det visade sig att Quizer har lägre antalet operationer (musklick) i en specifik uppgift än vad plattformen FlexiQuiz har. / Today, thousands of students are examined with the support of quizzes that exist in the form of quizzes where the premises are that students physically need to complete the examinations at the various higher education institutions. In this study, the Quizer project has been developed with the aim of trying to simplify and streamline digital evaluations for learning and checking the level of knowledge. The javabased web application can save time and resources for teachers to create, distribute and grade students' level of knowledge with the support of Quizer. The purpose of this project has been to simplify and streamline the method of examining students by implementing a useful Quiz tool where the user base and administrative base are completely independent of the application developer's presence. To plan the project, brainstorming, ER diagrams for planning the database structure, flow charts for the different views in the application have been used. During the planning, various frameworks have also been examined to determine which frameworks are best suited for this particular one. The result is a Java-based web application that facilitates the examination of students.  With the help of Bootstrap, the implementation of the application has reached its goals within a certain time frame. The results also show that the method gives a time gain of about 20 minutes compared to an exam in regular form. Results of the usability tests as a whole show that the application has an interface that is user-friendly because the average value of "experience of the application" resulted in 4, 25 out of 5 possible. A comparison has also been made with existing frameworks where it turned out that Quizer has a lower number of operations (mouse clicks) in a specific task than the FlexiQuiz platform has.

The ionosphere is a constantly changing medium. From the sun to cosmic rays, the ionosphere proves to be a continually interesting area of study. The most notable change that occurs in the ionosphere is the day and night cycle. The ionosphere is not a singular medium, but rather made up of different sections. The day side of the ionosphere consists of a D, E, F1, and F2 layer. The night day of the ionosphere consists of an E and F layer. These layers all have different properties and characteristics associated with them. A notable interaction is how radio waves propagate through the ionosphere. A radio wave can either reflect, refract, or pass through a layer of the ionosphere depending on the frequency of the signal, among other sources of disturbance. The ability to have a radio wave reflected back downwards is a core principle of an ionosonde, which measures the height of the ionosphere. A solar eclipse presents a night side ionosphere condition during the day. The change in the ionosphere that the eclipse will cause is something not a lot of research has gone into. This thesis aims to elaborate on the design and development of an ionosonde along with eventual ionosphere readings during the August 2017 total solar eclipse. / Master of Science / The atmosphere that surrounds the earth is made up of various unique regions. The region of interest for this thesis is the ionosphere. The ionosphere plays an important role in wireless communication of radio waves. It follows that changes in the ionosphere are something of great interest and study. A notable change that the ionosphere undergoes on a daily basis is the shift from the day side to the night side. A solar eclipse serves not only as a spectacular sight, but also to bring a night side condition to the day side. This thesis aims to uncover the changes that will occur to the ionosphere during the August 2017 total solar eclipse.

Cloud computing refers to the combination of large scale hardware resources at datacenters integrated by system software that provides services, commonly known as Software-as-a-Service (SaaS), over the Internet. As a result of more affordable datacenters, cloud computing is slowly making its way into the mainstream business arena and has the potential to revolutionize the IT industry. As more cloud computing solutions become available, it is expected that there will be a shift to what is sometimes referred to as the Web Operating System. The Web Operating System, along with the sense of infinite computing resources on the “cloud” has the potential to bring new challenges in software engineering. The motivation of this report, which is divided into two parts, is to understand these challenges. The first part gives a brief introduction and analysis of cloud computing. The second part focuses on Google’s cloud computing platform and evaluates the implementation of a micro blogging site using Google’s App Engine. / text

(POO) est l’utilisation de patrons de conception (PC). Un PC est un arrangement caractéristique de classes permettant d’offrir une solution éprouvée, tout en obtenant un code réutilisable et compréhensible. Plusieurs PC sont définis, dont 24 par la GoF [12] et plusieurs autres sont apparus par la suite. Le concept de PC est abstrait ce qui peut amener différentes interprétations. Ces différences peuvent aussi causer une mauvaise implémentation qui peut réduire les avantages d’utiliser ce patron. Ce projet consiste à concevoir un outil facilitant l’utilisation des PC. L’outil Génération et Restructuration de Patrons de Conception(GRPC) permet la génération automatique du squelette d’un patron de conception ainsi que la restructuration d’un code en le transformant structure respectant un PC. La génération et la restructuration automatique permettent d’obtenir un code uniforme et de qualité tout en respectant le patron de conception. La compréhension et la maintenance du code sont ainsi améliorées. GRPC est module d’extension pour l’environnement de développement Eclipse écrit en Java. Le code est conçu pour être facilement compréhensible et extensible. Les deux principaux objectifs de GRPC sont de restructurer (refactoring) une section de code vers l’architecture d’un patron de conception et de générer des squelettes de patrons de conception. Une interface graphique permet de guider l’utilisateur et d’aller chercher toutes les informations importantes pour le fonctionnement du logiciel. Elle permet aussi de configurer les éléments du patron de conception. Pour s’assurer de la possibilité d’effectuer une restructuration, chaque patron est associé avec une ou plusieurs règles qui analysent le code pour détecter la présence d’une structure particulière. Des procédures aident les développeurs à ajouter de nouveaux PC dans GRPC. GRPC fournit des fonctionnalités permettant d’implémenter quelques patrons de conception de la POO définis dans le livre Design Patterns : Elements of Reusable Object-Oriented Software.

Während der Sonnenfinsternis am 11. 8. 1999 kam es zu einer kurzzeitigen starken Abnahme der Ionisation im Höhenbereich der D-Region (60-90 km Höhe) am Unterrand der Ionosphäre. Mit bodengebundenen funktechnischen Beobachtungen der Ausbreitung elektromagnetischer Wellen über die D-Region konnte dieses Ereignis in charakteristischer Weise als ein simulierter Tag-Nacht-Übergang mit allen zu erwartenden Konsequenzen beobachtet werden. Auf der Basis von Funkwellen-Ausbreitungsmessungen werden in Collm (51.3°N, 13°E) Windmessungen im Höhenbereich der Mesopause und unteren Thermosphäre (80-105 km) durchgeführt, die in der Regel - bedingt durch die Besonderheiten der ionosphärischen Wellenausbreitung des verwendeten Frequenzbereiches - nur in den Nachtstunden möglich sind. Während der Hauptphase des Finsterniseffektes wurden Messungen auch am Tag möglich. Die Ergebnisse fügen sich gut in das aus den mittleren monatlichen Nachtwerten für die Tagstunden extrapolierte Niveau ein. Die Reaktion der Ionosphäre auf die Sonnenfinsternis erfolgte mit geringer Verzögerung: der maximale Effekt war 5-10 Minuten nach der größten Abdeckung der Sonnenscheibe zu verzeichnen. / During the solar eclipse on 11 August 1999 a short-term decrease of ionisation in the D-region ( 60- 90 km altitude) at the lower boundary of the ionosphere appeared. Using ground-based measurements of radio-wave propagation through the D-region the event could be monitored as a simulated day-night-transition with the expected consequences for the ionosphere. At Collm (51.3°N, 13°E), mesopause region (80-105 km) windmeasurements are carried out based on radio wave propagation, which are not possible in summer during daylight hours due to radio-wave absorption. During the eclipse measurements became possible for a short period. Tue results fit well to mean monthly daytime data extrapolated from nighttime measurements. The reaction of the ionosphere on the solar eclipse was fast; the maximum effect was registered only 5-10 minutes after the maximum eclipse of the solar disk.

The goal of this thesis was to design the support for output breakpoints in the Java language and implement the designed solution including integration into the Eclipse IDE. An output breakpoint represents a location in an output media (e.g. file, standard output or socket) where the execution of program should stop. The location in the output media is generalized as a stop condition - it can be in the form of absolute position, a particular line and a character or an occurrence of a text string. The designed solution is based on observing the classes responsible for output using entry method breakpoints that are a standard part of the Java language. This solution is dependent on a particular version and implementation of JRE because some of observed methods are not a part of public Java API.