Transaction support for Geo-replicated storage system is one of the most popular challenges in the last few years. Some systems gave up for supporting transactions and let upper application layer to handle it. While some other systems tried with different solutions on guaranteeing the correctness of transactions and paid some efforts on performance improvements. However, there are very few systems that claim the supporting of ACID in the global scale. In this thesis, we have studied on various data consistency and transaction design theories such as Paxos, transaction chopping, transaction chain, etc. We have also analyzed several recent distributed transactional systems. As the result, a Geo-replicated transactional framework, namely Multi Data center Transaction Chain (MDTC), is designed and implemented. MDTC adopts transaction chopping approach, which brings more concurrency by chopping transactions into pieces. A two phase traversal mechanism is designed to validate and maintain dependencies. For cross data center consistency, a Paxos like majority vote protocol is designed and implemented as a state machine. Moreover, some tuning such as executing read-only transaction locally helps to improve performance of MDTC in different scenarios. MDTC only requires 1 cross data center message roundtrip for executing a distributed transaction globally. ACID properties are kept in MDTC. We have evaluated MDTC with an extended TPC-C benchmark on top of Cassandra. The results from various setups have been evaluated and the result shows that MDTC achieves a good performance on throughout and latency. Meanwhile it has very low abort rate and scales well for transactions executed in a global scale.

München, Techn. University, Diss., 2007.

<p>This report is about the thesis work PyNestGUI which goal was to make a graphical interface to the neuron simulator NEST. The report's first part is about how NEST works well as which graphical interface that where selected. The report then continues go through what a neuron is and how it works superficial. The final section of the report will cover how PyNestGUI is build and how the program works. The problem that the program solves is that it builds a model in NEST with user settings and connects neurons in a similar way as a minicolumn are interconnected. The programs purpose was that it would help the user to change the variables in an easy manner and produce results that can be visualized and save for later analysis. Results that the the program can plot from the simulation is from voltmeters and a spike detector connected all neurons. The program can also display an animation of the simulation so that the user will be able to see when and which neurons spikes and their connections.</p> / <p>Den här rapporten handlar om examensarbetet PyNestGUI som gick ut på att göra ett grafiskt gränssnitt till neuronsimulatorn NEST. Rapportens första del handlar om hur NEST fungerar samt vilket grafiskt gränssnitt som valdes ut. Sedan fortsätter rapporten med att ytligt gå igenom vad en neuron är och hur den fungerar. Sista delen av rapporten går igenom hur PyNestGUI är uppbyggt och hur programmet fungerar. Problemet som programmet löser är att den bygger upp en modell i NEST med användarens inställningar och kopplar ihop neuroner på liknande sätt som en minikolumn är sammankopplad. Programmets syfte var att det skulle hjälpa användaren kunna ändra på variabler på ett lätt sätt samt ge resultat som kan visualiseras och som användaren skulle kunna spara. Resultat som programmet kan visa av simuleringen är voltmätare och spikdetektor på samtliga neuroner. Programmet kan också visa en animation av simuleringen så att användaren ska kunna se när neuroner spikar och vilka dessa neuroner är sammankopplade med.</p>

<p>The<em> Model Based Testing </em>is one of the modern automated testing methodologies used to generate test suits automatically from the abstract behavioral or environmental models of the <em>System Under Test (SUT)</em>. The Generated test cases are abstract like models, but these test cases can also be transformed to the different test scripts or language specific test cases to execute them. The Model based testing can be applied in different ways and it has several dimensions during implementation that can be changes with nature of the SUT. Since model based testing is directly related with models, the model based testing can be applied at early stages of development that helps in validation of both models and requirements that could save time of test development at later stages. With the automatic generation of test cases, requirements change is very easy to handle with the model based testing as it requires fewer changes in the models and reduces rework. It is also easy to generate a large number of test cases with full coverage criteria using the model based testing that was hard to produce with traditional testing methodologies. Testing non-functional requirements is one field in which the model based testing is lacking; quality related aspects of the SUT difficult to be tested with the model based testing.</p><p>The effectiveness and performance of model based testing is directly related to the efficiency of CASE<em> </em>tool that implementing it. A variety of CASE tools based on models are currently in use in different industries. The Qtronic tool is one generating test cases from abstract model of SUT automatically.<em></em></p><p>In this master thesis detailed evaluation of the Qtronic test case generation technique, generation time, coverage criterion and quality of test cases are analyzed by modeling the <em>Session Initiating Protocol (SIP) </em>&<em> File Transfer Protocol. (FTP)</em>, Also generation of test cases from models<em> </em>manually and by using the Qtronic Tool<em>.</em> In order to evaluate the Qtronic tool, detailed experiments and comparisons of manually generated test cases and test case generated by the Qtronic are conducted. The results of the case studies show the efficiency of the Qtronic over traditional manual test case generation in many aspects. We also show that the model based testing is not effective applied on every system under test, for some simple systems manual test case generation might be a good choice. <em></em></p>

<p>Our objective in this thesis work is to analyze and manage the log files which are generated after a number of experiments series on different groups using C3Fire simulation environment. It includes analyzing and extracting information from log files, and then maintaining this information in a database. This should be presented with a web interface through ICEfaces Ajax framework for Java. Log Files are generated after a number of experiments series on the different groups. All sequences and information related to task performed by team in group is organized in session log files. The work is divided into different steps; first step is to analyze and extract data from log files, and properly arrange it in several different tables in a database, for this MySQL database is used to store the information. The web interface of log file management system is implemented using ICEfaces Ajax framework, and is based on the statistics of log files generated from the C3Fire environment.  User would be able to add/remove the log files, also can view or edit the details of each session log file in database through web interface. Different events can be generated, and logged for the session information.</p><p>C3Fire is an environment that supports training and research in team collaboration. The environment is mainly used in command, control and communication research, and in training of team decision making. Many humanitarian relief operations are doing their work without having any practice. When some disaster events occur, they cannot perform their jobs effectively. Effective and efficient relief operation is the need of humanity; even that’s not enough to move teams to the disaster place at right time; communication and co-ordination among the team members is the big factor to make effective and well-organized work. C3Fire is a simulation system which provides the training for team members to handle such type of disaster events, and makes the work more proficient at that time by doing effective coordination.</p>

<p>C3Fire is a micro-world that provides the simulation system, which is use to improve team management skills in fully controlled enviroment. C3Fire system can be used in research process where researcher can select some characteristics of the real world and create the well controlled simulation system. Training is used for developing skills to tackle with emergency situation. The purpose of our thesis is to develop and test, Communiacation and Self Organization cofigurations in a team training environment. Success of dealing with emergency management situation mostly depends on these training factors. In the first step we had studied different theories and research work relevant to Communication and Self Organization. In second step we studied the structure of the C3Fire then we developed different configurations based on communication and self-organization. In third step we test these training session with the real world participants. Finally we analyze the behavior of the participants while playing the game.</p>

<p>Road maintenance during the heavy snowfall is an important problem. In Sweden the government and municipalities together spend close to 0.3 thousand million SEK every year for winter road maintenance. Approximately half of it is snow removal cost, which in turn to a large extent depends on the routing of the snow-ploughing vehicles. In this thesis work, we wish to develop an application framework for optimized routing operation for these vehicles so that the total operational cost can be reduced at a significant level. In general, there are different characteristics of snow ploughing depending on the routing procedure, one is done after the snowfall and the other is during the snowfall. In this thesis work, we are only interested to find the set of routing paths during the snowfall where duration of snowfall is unknown. We present a new way of generating an initial solution that deals with the real operational network. The optimization algorithm works upon this initial solution and try to reduce the number of periodic paths.</p>

No description available.

<p>Organizations developing software intensive defense systems are today faced with a number challenges related to characteristics of both the market place and the system domain:</p><p>1. Systems grow ever more complex, consisting of tightly integrated mechanical, electrical/electronic and software components.</p><p>2. Systems are often developed in short series; ranging from only a few to a few hundred units.</p><p>3. Systems have very long life spans, typically 30 years or longer.</p><p>4. Systems are developed with high commonality between different customers; however systems are always customized for specific needs.</p><p>The goal of the research presented in this thesis is to investigate methods and tools to enable efficient development and maintenance of systems in such a context. The strategy adopted in this work is to utilize the forth system characteristic, high commonality, to achieve this.</p><p>One approach to software reuse, which could be a potential solution as it enables reuse of common parts but at the same time allow for variations, is known as software product line development. The basic idea of this approach is to use domain knowledge to identify common parts within a family of related products and to separate them from the differences between the products. The commonalties are then used to create a product platform that can be used as a common baseline for all products within such a product family.</p><p>The main contribution of this licentiate thesis is a product line use case modeling approach tailored towards organizations developing software intensive defense systems. We describe how a common and complete use case model can be developed and maintained for a whole family of products, and how the variations within such a family are modeled using a feature model. Concrete use case models, for particular products within a family, can then be generated by selecting features from a feature model. We furthermore describe extensions to the commercial requirements management tool Telelogic DOORS and the UML modeling tool IBM-Rational Rose to support the proposed approach.</p><p>The approach was applied and evaluated in an industrial case study in the target domain. Based on the collected case study data we draw the conclusion that the approach performs better than modeling according to the styles and guidelines specified by the IBM-Rational Unified Process (RUP) in the current industrial context. The results however also indicate that for the approach to be successfully applied, stronger configuration management and product planning functions than traditionally found in RUP projects are needed.</p>

No description available.