ONKI-projektin ontologiaeditorien vertailuraportti

Kansalliskirjastossa maaliskuussa 2013 käynnistynyt ONKI-projekti vastaa yleisen suomalaisen ontologian (YSO) sekä kansallisen ONKI-ontologiapalvelun kehityksestä ja ylläpidosta. ONKI-projektia rahoittavat valtiovarainministeriö sekä opetus- ja kulttuuriministeriö. Projektin alkuvaiheen ensimmäisiä tavoitteita on ollut vertailla tällä hetkellä tarjolla olevia ontologioiden muokkaukseen käytettäviä ohjelmistoja, joista tästedes käytämme nimeä ontologiaeditori. Vertailun perusteella annetaan yhteenveto ja suositus vertailussa olleista vaihtoehdoista. Ontologia- editori on keskeisin työväline projektin jatkovaiheessa ja vastaavia työkaluja käyttävät myös Kansalliskirjaston ulkopuoliset, ONKI-projektiin liittyvät yhteistyötahot. Raportissa esitellään projektin taustaa ja ontologiaeditorien käyttöä ja merkitystä ontologiatyössä sekä niihin liittyvät perusvaatimukset. Vertailussa olleet editorit, Top Braid Composer eri versioineen, Protégé 4.3, TopBraid EVN, PoolParty Thesaurus Server, VocBench, IQvoc sekä TemaTres esitellään kukin erikseen. Lopuksi esitetään yhteenveto ja suositus.

Suunnistussovelluksen suunnittelu Windows Phonelle

Tässä työssä luotiin suunnistussovelluksen demo Windows Phone 8:lle. Työn tavoite oli tehdä sovellus, jonka kanssa suunnistaminen tuntuisi mahdollisimman samalta, kuin oikeakin suunnistus. Työssä kiinnitettiin huomiota lähinnä sovelluksen tekniseen toteutukseen sekä paikannuksen riittävään tarkkuuteen. Työssä vertaillaan eri mobiilialustoja, selainten tietokantaratkaisuja, erilaisia selaimen ja serverin tietokantojen synkronointimenetelmiä sekä olemassaolevia suunnistussovelluksia. Työssä käytettiin indeksitietokantaa, jQuery mobilea ja Cordovaa sekä JSON:ia tietokantojen synkronointiin. Työssä tehty demo on lupaava esitys siitä, miten suunnistustaitojaan voisi harjoittaa tekniikkaa apuna käyttäen. Lopuksi työssä käydään vielä läpi sitä, mitä tällaiseen palveluun voisi toteuttaa työssä toteutetun demon lisäksi.

Design and validation of stateful composite RESTful web services

A web service is a software system that provides a machine-processable interface to the other machines over the network using different Internet protocols. They are being increasingly used in the industry in order to automate different tasks and offer services to a wider audience. The REST architectural style aims at producing scalable and extensible web services using technologies that play well with the existing tools and infrastructure of the web. It provides a uniform set of operation that can be used to invoke a CRUD interface (create, retrieve, update and delete) of a web service. The stateless behavior of the service interface requires that every request to a resource is independent of the previous ones facilitating scalability. Automated systems, e.g., hotel reservation systems, provide advanced scenarios for stateful services that require a certain sequence of requests that must be followed in order to fulfill the service goals. Designing and developing such services for advanced scenarios with REST constraints require rigorous approaches that are capable of creating web services that can be trusted for their behavior. Systems that can be trusted for their behavior can be termed as dependable systems. This thesis presents an integrated design, analysis and validation approach that facilitates the service developer to create dependable and stateful REST web services. The main contribution of this thesis is that we provide a novel model-driven methodology to design behavioral REST web service interfaces and their compositions. The behavioral interfaces provide information on what methods can be invoked on a service and the pre- and post-conditions of these methods. The methodology uses Unified Modeling Language (UML), as the modeling language, which has a wide user base and has mature tools that are continuously evolving. We have used UML class diagram and UML state machine diagram with additional design constraints to provide resource and behavioral models, respectively, for designing REST web service interfaces. These service design models serve as a specification document and the information presented in them have manifold applications. The service design models also contain information about the time and domain requirements of the service that can help in requirement traceability which is an important part of our approach. Requirement traceability helps in capturing faults in the design models and other elements of software development environment by tracing back and forth the unfulfilled requirements of the service. The information about service actors is also included in the design models which is required for authenticating the service requests by authorized actors since not all types of users have access to all the resources. In addition, following our design approach, the service developer can ensure that the designed web service interfaces will be REST compliant. The second contribution of this thesis is consistency analysis of the behavioral REST interfaces. To overcome the inconsistency problem and design errors in our service models, we have used semantic technologies. The REST interfaces are represented in web ontology language, OWL2, that can be part of the semantic web. These interfaces are used with OWL 2 reasoners to check unsatisfiable concepts which result in implementations that fail. This work is fully automated thanks to the implemented translation tool and the existing OWL 2 reasoners. The third contribution of this thesis is the verification and validation of REST web services. We have used model checking techniques with UPPAAL model checker for this purpose. The timed automata of UML based service design models are generated with our transformation tool that are verified for their basic characteristics like deadlock freedom, liveness, reachability and safety. The implementation of a web service is tested using a black-box testing approach. Test cases are generated from the UPPAAL timed automata and using the online testing tool, UPPAAL TRON, the service implementation is validated at runtime against its specifications. Requirement traceability is also addressed in our validation approach with which we can see what service goals are met and trace back the unfulfilled service goals to detect the faults in the design models. A final contribution of the thesis is an implementation of behavioral REST interfaces and service monitors from the service design models. The partial code generation tool creates code skeletons of REST web services with method pre and post-conditions. The preconditions of methods constrain the user to invoke the stateful REST service under the right conditions and the post condition constraint the service developer to implement the right functionality. The details of the methods can be manually inserted by the developer as required. We do not target complete automation because we focus only on the interface aspects of the web service. The applicability of the approach is demonstrated with a pedagogical example of a hotel room booking service and a relatively complex worked example of holiday booking service taken from the industrial context. The former example presents a simple explanation of the approach and the later worked example shows how stateful and timed web services offering complex scenarios and involving other web services can be constructed using our approach.

It’s a workflow engine. It’s working with linked data. It’s repository! – Supporting electronic thesis related processes in University of Helsinki library

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

E-thesis repository – processes and data

Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

A distributed, cloud-ready, digital content processing and transformation platform and a specific use case

Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

SYLI - an external workflow system for DSpace

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Integration of JINR Information Resources

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Big Data Processing in the Cloud: a Hydra/Sufia Experience

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

DSpace for Data Revisited

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Tag Cloud of Search Queries for Repository System

Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

AOD 2.0: A category based submission add-on for DSpace 4.0

Presentation at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

SimpleREST -RESTful DSpace API

Poster at Open Repositories 2014, Helsinki, Finland, June 9-13, 2014

Development of remote monitoring process tools for biomass fired bubbling fluidized bed boilers

Remote monitoring of a power boiler allows the supplying company to make sure that equipment is used as supposed to and gives a good chance for process optimization. This improves co-operation between the supplier and the customer and creates an aura of trust that helps securing future contracts. Remote monitoring is already in use with recovery boilers but the goal is to expand especially to biomass-fired BFB-boilers. To make remote monitoring possible, data has to be measured reliably on site and the link between the power plant and supplying company’s server has to work reliably. Data can be gathered either with the supplier’s sensors or with measurements originally installed in the power plant if the plant in question is not originally built by the supplying company. Main goal in remote monitoring is process optimization and avoiding unnecessary accidents. This can be achieved for instance by following the efficiency curves and fouling in different parts of the process and comparing them to past values. The final amount of calculations depends on the amount of data gathered. Sudden changes in efficiency or fouling require further notice and in such a case it’s important that dialogue toward the power plant in question also works.

Cost-efficient virtual machine management : provisioning, admission control, and consolidation

One of the main challenges in Software Engineering is to cope with the transition from an industry based on software as a product to software as a service. The field of Software Engineering should provide the necessary methods and tools to develop and deploy new cost-efficient and scalable digital services. In this thesis, we focus on deployment platforms to ensure cost-efficient scalability of multi-tier web applications and on-demand video transcoding service for different types of load conditions. Infrastructure as a Service (IaaS) clouds provide Virtual Machines (VMs) under the pay-per-use business model. Dynamically provisioning VMs on demand allows service providers to cope with fluctuations on the number of service users. However, VM provisioning must be done carefully, because over-provisioning results in an increased operational cost, while underprovisioning leads to a subpar service. Therefore, our main focus in this thesis is on cost-efficient VM provisioning for multi-tier web applications and on-demand video transcoding. Moreover, to prevent provisioned VMs from becoming overloaded, we augment VM provisioning with an admission control mechanism. Similarly, to ensure efficient use of provisioned VMs, web applications on the under-utilized VMs are consolidated periodically. Thus, the main problem that we address is cost-efficient VM provisioning augmented with server consolidation and admission control on the provisioned VMs. We seek solutions for two types of applications: multi-tier web applications that follow the request-response paradigm and on-demand video transcoding that is based on video streams with soft realtime constraints. Our first contribution is a cost-efficient VM provisioning approach for multi-tier web applications. The proposed approach comprises two subapproaches: a reactive VM provisioning approach called ARVUE and a hybrid reactive-proactive VM provisioning approach called Cost-efficient Resource Allocation for Multiple web applications with Proactive scaling. Our second contribution is a prediction-based VM provisioning approach for on-demand video transcoding in the cloud. Moreover, to prevent virtualized servers from becoming overloaded, the proposed VM provisioning approaches are augmented with admission control approaches. Therefore, our third contribution is a session-based admission control approach for multi-tier web applications called adaptive Admission Control for Virtualized Application Servers. Similarly, the fourth contribution in this thesis is a stream-based admission control and scheduling approach for on-demand video transcoding called Stream-Based Admission Control and Scheduling. Our fifth contribution is a computation and storage trade-o strategy for cost-efficient video transcoding in cloud computing. Finally, the sixth and the last contribution is a web application consolidation approach, which uses Ant Colony System to minimize the under-utilization of the virtualized application servers.