Hybrid LC Filter for Power Electronic Drives: Theory and Implementation

Power electronic converter drives use, for the sake of high efficiency, pulse-width modulation that results in sequences of high-voltage high-frequency steep-edged pulses. Such a signal contains a set of high harmonics not required for control purposes. Harmonics cause reflections in the cable between the motor and the inverter leading to faster winding insulation ageing. Bearing failures and problems with electromagnetic compatibility may also result. Electrical du/dt filters provide an effective solution to problems caused by pulse-width modulation, thereby increasing the performance and service life of the electrical machines. It is shown that RLC filters effectively decrease the reflection phenomena in the cable. Improved (simple, but effective) solutions are found for both differential- and common-mode signals; these solutions use a galvanic connection between the RLC filter star point and the converter DC link. Foil chokes and film capacitors are among the most widely used components in high-power applications. In actual applications they can be placed in different parts of the cabinet. This fact complicates the arrangement of the cabinet and decreases the reliability of the system. In addition, the inductances of connection wires may prevent filtration at high frequencies. This thesis introduces a new hybrid LC filter that uses a natural capacitance between the turns of the foil choke based on integration of an auxiliary layer into it. The main idea of the hybrid LC filter results from the fact that both the foil choke and the film capacitors have the same roll structure. Moreover, the capacitance between the turns (“intra capacitance”) of the foil inductors is the reason for the deterioration of their properties at high frequencies. It is shown that the proposed filter has a natural cancellation of the intra capacitance. A hybrid LC filter may contain two or more foil layers isolated from each other and coiled on a core. The core material can be iron or even air as in the filter considered in this work. One of the foils, called the main foil, can be placed between the inverter and the motor cable. Other ones, called auxiliary foils, may be connected in star to create differential-mode noise paths, and then coupled to the DC link midpoint to guarantee a traveling path, especially for the common-mode currents. This way, there is a remarkable capacitance between the main foil and the auxiliary foil. Investigations showed that such a system can be described by a simple equivalent LC filter in a wide range of frequencies. Because of its simple hybrid construction, the proposed LC filter can be a cost-effective and competitive solution for modern power drives. In the thesis, the application field of the proposed filter is considered and determined. The basics of hybrid LC filter design are developed further. High-frequency behaviour of the proposed filter is analysed by simulations. Finally, the thesis presents experimental data proving that the hybrid LC filter can be used for du/dt of PWM pulses and reduction of common-mode currents.

Resources and capabilities approach to online strategy – Multiple-case study of Finnish magazines' online services

Most Finnish periodical magazines have a website, often an online service. The objective of this thesis is to understand the magazines’ resources and capabilities and match them with online strategies’ goals and objectives. The thesis’ theoretical part focuses on explaining and classifying resources, capabilities, goals and objectives, and applying everything into Finnish magazine publishing context. In the empirical part, there is a comparative case study of four magazines. The findings indicate that with cooperating, advertising and community hosting capabilities magazines may utilize their human, brand, content and customer base resources. The resources can be further addressed to reach profitability, customer-centricity and brand congruency goals.

Software Licensing: Implementing Electronic Licensing in Medical Technology Company

The purpose of this thesis is to examine software licensing, how a software developer can benefit from it and to define specifications for licensing system of software based medical technology product. The thesis has been divided into theoretical and empirical parts. In the theoretical part the concept of software licensing and different aspects that are connected to it are examined with a help of research material. On the ground of this research, in the empirical part, a licensing system for a medical software product called iCentral is designed. The empirical part is based on interviews, questionnaire and on authors own experience gained while working for the case-company.The thesis has great practical importance for the case-company by proposing both an ideal, and more importantly, practical implementation for a licensing system of a product. Thesis shows that electronic licensing is a viable option to sell medical technology products without a need to revise existing procedures or the enterprise resource system in the case company.

Rahatalous

Suomen Pankin kirjaston rahatalouden kokoelma on maan kattavin ja monipuolisin rahatalouteen ja rahoitusmarkkinoihin painottunut kokoelma. Kokoelmaan kuuluu merkittävä määrä nimekkeitä, joita ei ole hankittu muihin suomalaisiin kirjastoihin. Rahatalouden kokoelma koostuu monografioista, painetuista kausijulkaisuista ja elektronisista lehtitietokannoista. Kokoelma on painottunut tieteelliseen kirjallisuuteen, joka tukee pankissa tehtävää tutkimusta. Lisäksi aineistossa on huomattava määrä yleistajuista kirjallisuutta rahatalouden eri aihealueilta. Rahatalouden kokoelmaan kuuluu monografioita n. 9000 nimekettä (joulukuu 2010). Kokoelma käsittää nimekkeitä useilta eri aihealueilta, kuten rahapolitiikka ja rahateoria (n. 900), valuutat, valuuttajärjestelmät ja valuuttakurssit (n. 1100), pankkitoiminta ja keskuspankit (n. 1300), rahoitusmarkkinat (n. 1700), yleinen talousteoria ja oppihistoria (n. 1300), talouspolitiikka ja -historia (n. 450), hyöty- ja hintateoriat (n. 300), taloudellinen kasvu ja kansantulo (n. 700), suhdanteet (n. 250), julkinen talous ja verotus (n. 400) ja ekonometria (n. 600). Lehtiä kokoelmaan kuuluu n. 300 nimekettä, joista edelleen tilataan 200 nimekettä. Osa lehdistä löytyy painettuna ja osa on käytettävissä kirjastoon hankittujen elektronisten lehtitietokantojen kautta. Kokoelma karttuu pääosin ostojen kautta ja uutta aineistoa hankitaan jatkuvasti. Kokoelmaa on kartutettu systemaattisesti 1950-luvulta lähtien, minkä vuoksi siihen kuuluu merkittävästi vanhempaa aineistoa. Kokoelmaan kuuluvista kirjoista n. 26 % on julkaistu 2000-luvulla ja n. 21 % 1990-luvulla. Varsin suuri osa kirjoista, n. 29 %, on julkaistu 1970- ja 1980-luvulla. Ennen vuotta 1950 julkaistua aineistoa on n. 10 % kokoelmasta. Aineisto on valtaosin englanninkielistä, mutta kokoelmaan kuuluu myös suomen-, ruotsin- ja saksankielisiä nimekkeitä. Monografiat on luokiteltu Suomen Pankin kirjaston oman luokitusjärjestelmän mukaan. Kokoelmaa säilytetään Suomen Pankin kirjaston tiloissa jaettuna avokokoelmaan ja varastokokoelmaan. Aineiston ensisijaisia käyttäjiä ovat pankin oma henkilökunta, mutta kirjasto on avoinna myös kaikille ulkoisille asiakkaille. Kokoelma on lainattavissa muutamia poikkeuksia lukuun ottamatta.

Suomen Pankin julkaisut

Kokoelmaan kuuluu Suomen Pankin julkaisemaa aineistoa 1870-luvulta lähtien. Kokoelma sisältää vuosikertomuksia, vuosikirjoja, tieteellisiä julkaisuja kuten keskustelualoitteita, työpapereita ja muita tutkimusjulkaisuja, Suomen Pankin ennusteita, selvityksiä, raportteja ja lehtiä. Kokoelmaan kuuluu lisäksi taloudellista kehitystä kuvaavia pitkiä tilastosarjoja, joista osa on erillisiä julkaisuja ja osa on ilmestynyt Suomen Pankin muissa julkaisuissa, kuten vuosikirjoissa tai lehdissä. Tilastoihin kuuluvat mm. maksutase-, valuuttakurssi-, rahoitusmarkkina-, arvopaperi- ja korkotilastot sekä hintatasoa kuvaavat ja rahan määrän kehitystä seuraavat tilastot. Kokoelmaan kuuluu myös Suomen Pankista tehdyt historiikit, joista vanhin on vuodelta 1914. Suomen Pankin julkaisuja löytyy sekä painettuna että elektronisena. Lähes kaikki 1990-luvun puolivälin jälkeen ilmestyneet julkaisut on saatavilla elektronisena Suomen Pankin verkkosivujen kautta. Vanhemmat julkaisut on osittain digitoitu, ja tällä hetkellä elektronisena on saatavilla uudempien julkaisujen lisäksi mm. Suomen Pankin keskustelualoitteet, Bank of Finland (Montly) Bulletin ja Suomen Pankin vuosikirjat. Kokoelmassa on yhteensä n. 4000 nimekettä, ja kokoelma karttuu jatkuvasti. Kokoelman muodostavista julkaisuista n. 13 % on ilmestynyt ennen 1950 lukua ja n. 36 % vuosina 1950–1989. Yli 50 % julkaisuista on 1990- ja 2000-luvuilta. Aineisto on valtaosin suomen- ja englanninkielistä, mutta kokoelmaan kuuluu myös ruotsinkielisiä julkaisuja. Kokoelman painettua osaa säilytetään Suomen Pankin kirjaston tiloissa avokokoelmassa. Kirjasto on avoinna ulkoisille asiakkaille, ja Suomen Pankin julkaisut ovat lainattavissa joitakin poikkeuksia, kuten käsikirjoja, lukuun ottamatta. Julkaisuista voi ottaa kopioita maksutta.

Licensing of eResources - views from Denmark's Electronic Research Library (DEFF)

Bo Öhrströmin esitys Kirjastoverkkopäivillä 27.10.2011 Helsingissä.

Usable Privacy Preservation in Mobile Electronic Personality

Personalised ubiquitous services have rapidly proliferated due technological advancements in sensing, ubiquitous and mobile computing. Evolving societal trends, business and the economic potential of Personal Information (PI) have overlapped the service niches. At the same time, the societal thirst for more personalised services has increased and are met by soliciting deeper and more privacy invasive PI from customers. Consequentially, reinforcing traditional privacy challenges and unearthed new risks that render classical safeguards ine ective. The absence of solutions to criticise personalised ubiquitous services from privacy perspectives, aggravates the situation. This thesis presents a solution permitting users' PI, stored in their mobile terminals to be disclosed to services in privacy preserving manner for personalisation needs. The approach termed, Mobile Electronic Personality Version 2 (ME2.0), is compared to alternative mechanisms. Within ME2.0, PI handling vulnerabilities of ubiquitous services are identi ed and sensitised on their practices and privacy implications. Vulnerability where PI may leak through covert solicits, excessive acquisitions and legitimate data re-purposing to erode users privacy are also considered. In this thesis, the design, components, internal structures, architectures, scenarios and evaluations of ME2.0 are detailed. The design addresses implications and challenges leveraged by mobile terminals. ME2.0 components and internal structures discusses the functions related to how PI pieces are stored and handled by terminals and services. The architecture focusses on di erent components and their exchanges with services. Scenarios where ME2.0 is used are presented from di erent environment views, before evaluating for performance, privacy and usability.

From electronic spare part catalog to eBusiness: Finding the best practices

Companies and organizations business activities rely on information. IT systems that manage master data must provide the highest level of service, world-class scalability and reliable information. This study discusses product information and how it can support the creation of a spare part catalog and the launching of eBusiness. The study consists of a theoretical and empirical part. The theoretical part contains a literature review and a framework for the analysis. For the empirical study two companies were selected and their information management processes were studied and analyzed based on the framework. The empirical results indicate that the challenges the companies face reflect the ones that can be found in the literature study. The results of the empirical study also show that the companies had recognized the issues which need to be developed and had recognized trends in eBusiness and product information management.

Integration of Electronic Commerce and Enterprise Systems

The necessity of EC (Electronic Commerce) and enterprise systems integration is perceived from the integrated nature of enterprise systems. The proven benefits of EC to provide competitive advantages to the organizations force enterprises to adopt and integrate EC with their enterprise systems. Integration is a complex task to facilitate seamless flow of information and data between different systems within and across enterprises. Different systems have different platforms, thus to integrate systems with different platforms and infrastructures, integration technologies, such as middleware, SOA (Service-Oriented Architecture), ESB (Enterprise Service Bus), JCA (J2EE Connector Architecture), and B2B (Business-to-Business) integration standards are required. Huge software vendors, such as Oracle, IBM, Microsoft, and SAP suggest various solutions to address EC and enterprise systems integration problems. There are limited numbers of literature about the integration of EC and enterprise systems in detail. Most of the studies in this area have focused on the factors which influence the adoption of EC by enterprise or other studies provide limited information about a specific platform or integration methodology in general. Therefore, this thesis is conducted to cover the technical details of EC and enterprise systems integration and covers both the adoption factors and integration solutions. In this study, many literature was reviewed and different solutions were investigated. Different enterprise integration approaches as well as most popular integration technologies were investigated. Moreover, various methodologies of integrating EC and enterprise systems were studied in detail and different solutions were examined. In this study, the influential factors to adopt EC in enterprises were studied based on previous literature and categorized to technical, social, managerial, financial, and human resource factors. Moreover, integration technologies were categorized based on three levels of integration, which are data, application, and process. In addition, different integration approaches were identified and categorized based on their communication and platform. Also, different EC integration solutions were investigated and categorized based on the identified integration approaches. By considering different aspects of integration, this study is a great asset to the architectures, developers, and system integrators in order to integrate and adopt EC with enterprise systems.

The Finnish Electronic Library - Basic Research Infrastructure

Kristiina Hormia-Poutasen esitys KRE-konferenssissa 2013.

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