Consistency of UML based designs using ontology reasoners

Software plays an important role in our society and economy. Software development is an intricate process, and it comprises many different tasks: gathering requirements, designing new solutions that fulfill these requirements, as well as implementing these designs using a programming language into a working system. As a consequence, the development of high quality software is a core problem in software engineering. This thesis focuses on the validation of software designs. The issue of the analysis of designs is of great importance, since errors originating from designs may appear in the final system. It is considered economical to rectify the problems as early in the software development process as possible. Practitioners often create and visualize designs using modeling languages, one of the more popular being the Uni ed Modeling Language (UML). The analysis of the designs can be done manually, but in case of large systems, the need of mechanisms that automatically analyze these designs arises. In this thesis, we propose an automatic approach to analyze UML based designs using logic reasoners. This approach firstly proposes the translations of the UML based designs into a language understandable by reasoners in the form of logic facts, and secondly shows how to use the logic reasoners to infer the logical consequences of these logic facts. We have implemented the proposed translations in the form of a tool that can be used with any standard compliant UML modeling tool. Moreover, we authenticate the proposed approach by automatically validating hundreds of UML based designs that consist of thousands of model elements available in an online model repository. The proposed approach is limited in scope, but is fully automatic and does not require any expertise of logic languages from the user. We exemplify the proposed approach with two applications, which include the validation of domain specific languages and the validation of web service interfaces.

Ylläpitosuunnittelun laadun arviointi ja mittaaminen

Tässä diplomityössä tutkittiin suunnittelupalvelun laatuun vaikuttavia tekijöitä sekä etsittiin keinoja mitata suunnittelupalvelun laatua. Diplomityön lähtökohtana oli tilanne, jossa suunnittelutoimisto toimittaa ylläpitosuunnittelupalvelua paperi- ja metsäteollisuuden alan yritykselle. Työssä selvitettiin yleisesti, mistä suunnittelupalvelun laatu muodostuu. Tärkeä osa työtä oli tutkia kyselytutkimuksen avulla, onko tilaajalla ja toimittajalla samanlaiset näkemykset laadun osalta. Kyselyt suoritettiin sekä haastatteluin että kirjallisesti. Vastauksia saatiin kaikkiaan 45 kappaletta. Kohdejoukko oli tarkasti määritelty koostuen sekä tilaajan että toimittajan edustajista. Työssähavaittiin, että suunnittelupalvelun laatuun ja toimittajan valintaan vaikuttavat hyvin paljon itse suunnitelmien laadun lisäksi henkilökohtaiset kokemukset palvelusta. Pahimmiksi riskitekijöiksi ylläpitosuunnittelulle koettiin lähtötietoihin liittyvät ongelmat sekä aikataulujen pettäminen. Näiden lisäksi työssä tehtiin selvitys suunnittelupalvelun laadun mittaristosta, jonka oikealla käytöllä voitaisiin luoda ohjausvaikutus suunnittelupalveluprosessiin paremman laadun ja tehokkaamman toiminnan aikaansaamiseksi.

Kartonkipakkauslinjaston anturointi

Tässä diplomityössä tutkitaan kartonkiastioiden valmistukseen tarkoitetun linjaston ohjausjärjestelmän anturoinnin tarpeita. Linjasto on suunniteltu Lappeenrannan teknillisen ylipiston pakkauslaboratorioon vastaamaan nykyaikaisen pakkaustuotannon tarpeita. Linjasto on suunniteltu modulaariseksi sekä mahdollisimman helposti muunneltavaksi. Työn tavoitteena on selvittää anturoinnin tarpeet moduulikohtaisesti sekä tehdä tarvittava mekaniikkasuunnittelu. Suunnittelussa otetaan huomioon elintarvikehygienia, turvallisuus, modulaarisuuden vaatimukset, tuotantomäärän tarpeet sekä muut toiminnan kannalta kriittiset tekijät. Tutkimuksen lopputuloksena saadaan valmistettavan prototyypin oikean toiminnan edellyttämät edulliset anturointiratkaisut oleellisimpien moduuleiden osalta. Lisäksi työssä esitetään jatkokehitysehdotuksia kun prototyyppi saadaan valmiiksi jolloin mittaustuloksia voidaan alkaa tutkimaan.

Primary and Revision Hip Replacement. A University Hospital Database and Registry Study

Large-headed total hip arthroplasty (THA) and hip resurfacing arthroplasty (HRA) with metal-on-metal (MoM) bearings became popular during the last decade. Recently, it has become evident that the large-head MoM hip implants are associated with increased revision rates despite their theoretical advantages. The purpose of this study was to evaluate the early results of primary MoM hip replacements and of acetabular revisions. I analyzed retrospectively the results of four MoM implant designs and the survival rate of acetabular revisions with impaction bone grafting, as documented in the Turku University Hospital database. Further, I evaluated the correlation between femoral head size and dislocation rate, and used the Finnish Arthroplasty Register data to compare the survival of three large-head MoM THAs to analogous HRAs. The early results for the Magnum M2A–ReCap THA were good. A larger head size decreased the risk of dislocation. Articular surface replacement (ASR) THA yielded inferior results compared to analogous HRA. For two other designs the results were similar. The R3–Synergy THA yielded inferior results compared to the reference implants. The survival of acetabular reconstructions with impaction bone grafting was inferior compared to previous reports. In conclusion, the early results of the Biomet ReCap–Magnum design were promising, and large head sizes decreased the dislocation rate. The survival of different MoM hip implant designs varied. The survival of new designs and techniques may be inferior to those reported by the clinics where implants are developed. An important caveat is that early promising results of new devices may rapidly worsen. New implants need to be introduced in a controlled fashion to the market; here, arthroplasty registers are a valuable tool that needs to be used.

Comparison of Different Concentrated Solar Power Collector Designs and Development of a Linear Fresnel Solar Collector Model

Concentrated solar power (CSP) is a renewable energy technology, which could contribute to overcoming global problems related to pollution emissions and increasing energy demand. CSP utilizes solar irradiation, which is a variable source of energy. In order to utilize CSP technology in energy production and reliably operate a solar field including thermal energy storage system, dynamic simulation tools are needed in order to study the dynamics of the solar field, to optimize production and develop control systems. The object of this Master’s Thesis is to compare different concentrated solar power technologies and configure a dynamic solar field model of one selected CSP field design in the dynamic simulation program Apros, owned by VTT and Fortum. The configured model is based on German Novatec Solar’s linear Fresnel reflector design. Solar collector components including dimensions and performance calculation were developed, as well as a simple solar field control system. The preliminary simulation results of two simulation cases under clear sky conditions were good; the desired and stable superheated steam conditions were maintained in both cases, while, as expected, the amount of steam produced was reduced in the case having lower irradiation conditions. As a result of the model development process, it can be concluded, that the configured model is working successfully and that Apros is a very capable and flexible tool for configuring new solar field models and control systems and simulating solar field dynamic behaviour.