The technology of object oriented databases was introduced to system developers in the late 1980?s. Despite that it is rarely used today. This thesis introduces the concept of object oriented databases as the purposed solution to the problems that exist with the use of relational databases. The thesis points to the advantages with storing the application objects in the database without disassembling them to fit a relational data model. Based on that advantages and the cost of introducing such a rarely used technology into a project, a guideline for when to use object oriented databases and when to use relational databases is given. / anders@actk.net

The purpose of this paper is to clarify the differences in latency between PostgreSQL and MongoDB as a consequence of their differences in software architecture. This has been achieved through benchmarking of Insert, Read and Update operations with the tool “Yahoo! Cloud Serving Benchmark”, and through source code analysis of both database management systems (DBMSs). The overall structure of the architecture has been researched with Big O notation as a tool to examine the complexity of the source code. The result from the benchmarking show that the latency for Insert and Update operations were lower for MongoDB, while the latency for Read was lower for PostgreSQL. The results from the source code analysis show that both DBMSs have a complexity of O(n), but that there are multiple differences in their software architecture affecting latency. The most important difference was the length of the parsing process which was larger for PostgreSQL. The conclusion is that there are significant differences in latency and source code and that room exists for further research in the field. The biggest limitation of the experiment consist of factors such as background processes which affected latency and could not be eliminated, resulting in a low validity.

This work deals with the problematics of conversion of UML diagrams to code. Initially, existing solutions in this field are analyzed. Based on the gained findings, a new tool is designed and implemened. It accepts UML class diagrams and database models from the free diagramming environment Dia and for each of these offers three target languages. The key feature of this tool is its modular design allowing new target languages to be added easily.

The thesis deals with implementation of a program which can, through the use of FUSE library, make data accessible in the relational database like the classical Gentoo Portage storage. First, the reader of the thesis becomes familiar with FUSE library itself. After that, the new data model is built based on the analysis of the Portage structure. The new model emphasizes especially dependencies of packages. The key implementation issues are also described in the next part. Finally, the thesis assesses outcomes achieved including comparison with standard Portage implementation and classical file system. The other possibilities of the project development are considered as well.

B-SPORT+ är ett projekt som var intresserat av att utveckla en applikation för tips och vägledning inom fysisk träning anpassad till personer med funktionsnedsättningar. B-SPORT+ identifieradebehovet av en decentraliserad ledger i applikationen. En ledger innebär en digital huvudbok som lagrar data över transaktioner utförda i en applikation. I ett tidigare arbete lyftes Blockkedja fram som en möjlig lösning för applikationen. B-SPORT+ upplevde dock att denna teknik innehöll nackdelar som hög energiförbrukning och dyr implementation. Därför skulle detta arbete undersöka,utveckla och utvärdera ett alternativ till Blockkedja med hjälp av relationsdatabaser. Resultatet blev två prototyper. Den första prototypen efterliknade Blockkedja-teknik genom att horisontellt fragmentera en relationsdatabas som innehöll en tabell för utförda transaktioner. Sedan användes hasning för att validera transaktioner mellan databas fragment. Det utvecklades även en prototyp med hjälp av Blockkedja-teknik, denna prototyp användes för att utvärdera den första prototypen. Utvärderingen visade att SQL-prototypens struktur minskade minnesutnyttjandet i användardatorer samt minskade den transaktioners energikonsumtionen och tid. Denna struktur tillät även moderering utav data i ledgern vilket var vitalt för den applikation B-SPORT+ ville utveckla / B-SPORT+ is a project that was interested in developing an application for advice and guidance in regards to physical exercise adapted for people with disabilities. B-SPORT+ identified the need for a decentralized ledger in the application. A decentralized ledger is a register that stores data on transactions performed in an application. In previous work on the application, a Blockchain was highlighted as a possible solution. However, B-SPORT+ experienced that this technology contained disadvantages such as high energy consumption and expensive implementation. Therefore, this work investigated, developed and evaluated an alternative to Blockchain using relational databases. The result was two prototypes. The first prototype mimicked Blockchain technology by horizontally fragmenting a relational database that stored a table of performed transactions. Then, cryptographic hashing was used to validate transactions between database fragments. A prototype was also developed using Blockchain technology, this prototype was used to evaluate the first prototype. The evaluation showed that the structure of the SQL prototype reduced memory utilization in user computers it also reduced energy consumption and time when performing transactions. This structure also allowed moderation of data in the ledger, which was vital for the application BSPORT + wanted to develop.

The world is becoming increasingly digitized, and with this trend comes an increas-ing need for storing data for companies of all sizes. For smaller enterprises, thiscould prove to be a major challenge due to limitations in knowledge and financialassets. So the purpose of this study is to investigate how smaller companies cansatisfy their needs for data storage and which database management system to usein order to not let their shortcomings hold their development and growth back. Tofulfill this purpose, a small wood processing company in Sweden is examined andused as an example. To investigate and answer the problem, literary research is con-ducted to gain knowledge about data storage and the different options for this thatexist. Microsoft Access, MySQL, and MongoDB are selected for evaluation andtheir performance is compared in controlled experiments. The results of this studyindicates that, due to the small amount of data that the example company possesses,the simplicity of Microsoft Access trumps the high performance of its competitors.However, with increasingly developed internet infrastructure, the option of hostinga database in the cloud has become a feasible option. If hosting the database in thecloud is the desired solution, Microsoft Access has a higher operating cost than theother alternatives, making MySQL come out on top.

<p>Online communication has increased the need to rapidly interpret complex emotions due to the volatility of the data involved; machine learning tasks that process text, such as sentiment analysis, can help address this challenge by automatically classifying text as positive, negative, or neutral. However, while much research has focused on detecting offensive or toxic language online, there is also a need to explore and understand the ways in which people express positive emotions and support for one another in online communities. This is where sentiment dictionaries and other computational methods can be useful, by analyzing the language used to express support and identifying common patterns or themes.</p> <p><br></p> <p>This research was conducted by compiling data from social question and answering around machine learning on the site Stack Exchange. Then a classification model was constructed using binary logistic regression. The objective was to discover whether predictions of marked solutions are accurate by treating the comments as reviews. Measuring collaboration signals may help capture the nuances of language around support and assistance, which could have implications for how people understand and respond to expressions of help online. By exploring this topic further, researchers can gain a more complete understanding of the ways in which people communicate and connect online.</p>

Higher demands on database systems have lead to an increased popularity of certain database system types in some niche areas. One such niche area is graph networks, such as social networks or logistics networks. An analysis made on such networks often focus on complex relational patterns that sometimes can not be solved efficiently by traditional relational databases, which has lead to the infusion of some specialized non-relational database systems. Some of the database systems that have seen a surge in popularity in this area are graph database systems. This thesis presents a prototype of a logistics network-related service using a graph database management system called Neo4j, which currently is the most popular graph database management system in use. The logistics network covered by the service is based on existing data from PostNord, Sweden’s biggest provider of logistics solutions, and primarily focuses on customer support and business to business. By creating a prototype of the service this thesis strives to indicate some of the positive and negative aspects of a graph database system, as well as give an indication of how a service using a graph database system could be created. The results indicate that Neo4j is very intuitive and easy to use, which would make it optimal for prototyping and smaller systems, but due to the used evaluation method more research in this area would need to be carried out in order to confirm these conclusions. / Högre krav på databassystem har lett till en ökad popularitet för vissa databassystemstyper i några nischområden. Ett sådant nischområde är grafnätverk, såsomsociala nätverk eller logistiknätverk. Analyser på grafnätverk fokuserar ofta påkomplexa relationsmönster som ibland inte kan lösas effektivt av traditionella relationsdatabassystem, vilket har lett till att vissa specialiserade icke-relationella databassystem har blivit populära alternativ. Många av de populära databassystemen inom detta område är grafdatabassystem. Detta arbete presenterar en prototyp av en logistiknätverksrelaterad tjänst som använder sig av ett grafdatabashanteringssystem som heter Neo4j, vilket är det mest använda grafdatabashanteringssystemet. Logistiknätverket som täcks av tjänsten är baserad på existerande data från PostNord, Sveriges ledande leverantör av logistiklösningar, och fokuserar primärt på kundsupport och företagsrelaterad analys. Genom att skapa en prototyp av tjänsten strävar detta arbete efter att uppvisa vissa av de positiva och negativa aspekterna av ett grafdatabashanteringssystem samt att visa hur en tjänst kan skapas genom att använda ett grafdatabashanteringssystem. Resultaten indikerar att Neo4j är väldigt intuitivt och lättanvänt, vilket skulle göra den optimal för prototyping och mindre system, men på grund av den använda evalueringsmetoden så behöver mer forskning inom detta område utföras innan dessa slutsatser kan bekräftas.

This research study focused on learning lessons from the experience of designing a comprehensive case-based reasoning (CBR) tool for support of complex thinking skills. Theorists have historically identified, analyzed, and classified different thinking processes and skills. Thinking skills have been increasingly emphasized in national standards, state testing, curricula, teaching and learning resources, and research agendas. Complex thinking is the core of higher-order thinking. Complex thinking is engaged when different types of thinking and action converge to resolve a real-world, ill-structured issue such as solving a problem, designing an artifact, or making a decision. By integrating reasoning, memory, and learning in a model of cognition for learning from concrete problem-solving experience, CBR can be used to engage complex thinking. In similar and different ways, CBR theory and the related theories of constructivism and constructionism promote learning from concrete, ill-structured problem-solving experience. Seven factors or characteristics, and by extension, design requirements, that should be incorporated in a comprehensive CBR tool were extracted from theory. These requirements were consistent with five theory-, research-based facilitators of learning from concrete experience. Subsequent application of the Dick, Carey, and Carey model to these design requirements generated twenty-nine specifications for design of the tool. This research study was carried out using developmental research methodology and a standard development model. The design process included front-end analysis, creating a prototype of the tool, and evaluating the prototype. / Ph. D.

I denna rapport undersöks olika system för hanteringen av forskning och utvecklingsprojekt som Stockholms stad kan använda som en gemensam plattform med syfte att sprida information och kunskap gällande projekt. Målet med rapporten var att hitta en anpassad kravspecifikation som summerade de tre kontorens gemensamma arbetsprocesser. Kravspecifikationen var ett hjälpmedel för att finna och utvärdera olika system som främjar hanteringen av Stockholms stads forskning och utvecklingsprojekt. En kravspecifikation har tagits fram i syfte att informera Stockholms stad om hur ett generellt arbetssätt ser ut bland de olika forskning och utvecklingskontoren. Genom informationsspridning internt pa kontoren kan effektiviteten öka då målkonikter kan undvikas och ett samarbete kan leda till ett bättre resultat. Att lagra informationen kopplade till ett projekt i en relationsdatabas visade sig passa kontoren bäst och skulle kunna möjliggöra vidare anpassning. Ytterligare en aspekt med systemen som utvärderades i rapporten var att de skulle kunna förbättra Stockholms stads kunskapsöverföring. Det kan medföra att innovativa och hållbara ideer sprids i större utsträckning än med kontorens nuvarande hantering av forskning- och utvecklingsprojekt. Resultatet av rapporten var två rekommendationer som togs fram utifrån utvärderingen av de utvalda systemen. Den kortsiktiga lösningen var att använda Excel med delad arbetsbok och den långsiktiga lösningen var att använda SharePoint Server som en gemensam kommunikationsplattform. / The purpose of this report is to find and evaluate different systems that can be used as a central platform for publishing information and knowledge about Stockholms stad's various projects spanning several agencies. The goal of this report was to present a requirement specification which summarize the three chosen agencies common work pattern. The requirement specification was used to find and evaluate the different systems that improves Stockholm's stads management of research and development projects. A requirement specification has been defined to help Stockholms stad to acknowledge a common work pattern for the three agencies presentation of project information. By increasing the dissemination of information internally, the efficiency will increase when goal conflicts are avoided and a formal cooperation can lead to better work results. A relational database was proven to be the best option for the agencies and could allow further development and adjustments to the agencies. One advantage with the systems evaluated in this report is that they could help Stockholms stad's transferal of knowledge. This could result in a wider spread of innovative and sustainable ideas than Stockholms stad's current system for managing research and development projects. The final recommendation from the evaluation of the selected systems gave Stockholms stad two possible solutions. The short-term solution was to use Excel with a shared workbook and the long-term solution was to use SharePoint Server as a common platform for communication.