Browsing by Author "Laakso, Mikko"

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  • Veden adsorptio huokoiseen piihin
    (1998) Kujanpää, Satu
     Helsinki University of Technology | Master's thesis
  • Raha-automaattipelien logiikkapohjan analysointi ja parannus
    (2010) Behr, Tommi von
     School of Science | Master's thesis
    Slot machine games have advanced significantly during last decade. They have wide range of features and graphics that rival last generation console games. Finnish Slot Machine Association (RAY) has developed and provided state-of-the-art slot machine games by incrementally adding new features and making small changes to their software codebase. During ten years this codebase has become awkward and cumbersome. Some refactoring and rewrite has been done to address issues in graphics components, but the codebase governing game logic is still mainly based on code that is ten years old. At the same time, RAY's new strategy demands for shorter development times and better quality games. It is clear that the old game logic isn't up to the task. In this thesis the feature requirements for major game logic upgrade are indentified. The old codebase is analysed based on requirements, and the parts that need refactoring and redesign are presented. A comprehensive software architecture plan is proposed for a new game logic layer that will match the requirements. Game logic template -concept is presented to help bring new features to games in future.
  • Assessing organizational factors in sales forecasting management. Case: Pfizer Oy
    (2008) Laakso, Mikko
     School of Business | Master's thesis
  • Design of an information capturing and visualization system of the visitors of Aalto University Design Factory
    (2013) Trivino Massó, Carles
     School of Engineering |
    Aalto University Design Factory, one of the spearhead projects of the recently formed Aalto University, is a meeting point for students, educators and practitioners from the fields of engineering, design and business. The Design Factory is a constantly evolving experimental platform for interdisciplinary education and collaboration related to product development. As Design Factory continues to grow from its birth four years ago, it is gaining worldwide interest, hosting various courses, along with projects, events and visits from different universities, institutions and companies, both national and international. This continuing development has presented a need for a system to efficiently collect information needed to help document visitors and activities. This thesis depicts a design project with the main goal of designing a system that helps capturing information from the visitors of the Design Factory in an easy, organized and programmable way. This system enables the Design Factory to start a database of visual and contact information of the people for internal documentation, research and external promotion and communication. As an outcome of the design project, a basic working prototype of the system was developed and provided to Design Factory for testing and further development. The system development process follows general product and systems design and project engineering methodologies and procedures with the documentation and reflections of the author serving as a future reference for development of similar types of projects.
  • Mittausmenetelmä aurinkokennojen materiaalin ja pinnan laatua kuvaavien parametrien määrittämiseksi kennon spektrivasteesta
    (1996) Marjamäki, Teemu
     Helsinki University of Technology | Master's thesis
  • Pienen maarakennusyrityksen ohjausjärjestelmän kehittäminen
    (1986) Laakso, Mikko
     Helsinki University of Technology | Master's thesis
  • Empirical evaluation of OFDM waveforms for VLC in the presence of LED nonlinearities
    (2021-09-13) Laakso, Mikko; Dowhuszko, Alexis A.; Wichman, Risto
     A4 Artikkeli konferenssijulkaisussa
    Visible Light Communications (VLC) rely on LED light sources to transmit information wirelessly, offering an alter-native air interface to contemporary mobile networks using Radio Frequency bands for wireless connectivity. Most commercial LEDs found in the market nowadays have been designed for illumination, showing a notable non-linear response when per-forming the Electrical-to-Optical (E/O) conversion, particularly when using deep Intensity Modulation (IM) indexes for increased useful radiated power. Several different OFDM-based waveforms, adapted to the unipolarity requirement that IM demands, have been proposed in the literature. However, the performance of most of these Optical OFDM waveforms is seriously affected by the non-linear magnitude distortion of the low-cost white LEDs, particularly when the Peak-to-Average Power Ratio (PAPR) is high. To tackle this issue, this paper analyzes the performance of Constant-Envelope (CE) OFDM, a waveform that modulates the phase of an Intermediate Frequency (IF) carrier with a real-valued OFDM signal before its E/O conversion. The Bit Error Rate of CE-OFDM is compared to the one of DC-biased Optical OFDM and passband OFDM using a software-defined VLC demonstrator. CE-OFDM allows the VLC system to work in energy-efficient regimes, thanks to its robustness to the non-linear magnitude distortion introduced by the LED.
  • Investigation of a personnel neutron dosimeter with direct indication
    (1985) Laakso, Mikko
     Helsinki University of Technology | Master's thesis
  • LTE-järjestelmän verkkoarkkitehtuuri
    (2013-05-27) Laakso, Mikko
     Sähkötekniikan korkeakoulu | Bachelor's thesis
  • Lua scripting in slot game machines: Applicability to speeding up development
    (2010) Neuvonen, Ilkka
     School of Science | Master's thesis
  • Toteutussuunnittelun ohjaus projektinjohtototeutuksessa
    (2006) Heikkinen, Maija
     Helsinki University of Technology | Master's thesis
    Tämä diplomityö on tehty osana Suunnittelujärjestelmien kehittäminen talonrakennuksen projektinjohtototeutuksessa (SUKE) -tutkimusprojektia. Tutkimuksessa kartoitettiin kirjallisuuden esittämiä suunnittelun ja suunnittelun ohjauksen prosesseja, tarkasteltiin todellisten hankkeiden hankinta- ja suunnitteluprosesseja, suunnitelma-asiakirjoja, suunnittelun ohjausta ja suunnittelun ongelmia sekä hankintojen ja suunnittelun yhteensovitusta. Lisäksi testattiin SUKE -projektin hypoteeseja. Tavoitteena oli laatia pj-yritykselle menettelyohje ja malliasiakirjoja toteutussuunnittelun ohjauksen tueksi. Hankinnan ja tuotannon kannalta suurimmiksi suunnitteluun liittyviksi ongelmiksi todettiin suunnitelmien puutteet, virheet, ristiriitaisuudet ja liian myöhäinen toimitus, useat suunnitelmamuutokset sekä epätietoisuus eri osapuolien vastuista ja suunnittelurajoista. Myös tiedonkulussa on ongelmia. Perinteisen suunnitelma-aikataulun todettiin olevan riittämätön keino suunnittelun ohjaukseen. Suunnitelmien toimituksesta ja sisällöstä sovittaessa ei huomioida riittävästi hankintajakoa. Projektinjohtototeutuksessa tärkeä tavoite on joustavuus suunnittelun suhteen toteutuksen aikana sekä suunnittelun, hankintojen ja rakentamisen toteuttaminen työn edistymisen tahdissa ns. limitetyn aikataulun mukaan. Hankkeen onnistumisen kannalta tärkeitä ovat oikea hankintajako sekä hankintaa ja tuotantoa palveleva suunnittelu. SUKE -mallin mukaisesti suunnitelmat jaetaan kiinteän (talo-osa) ja muuntuvan (tilaosa) osan suunnitelmiin Toteutussuunnitelmilla voi olla kaksi valmiusastetta; hankintoja varten ja myöhemmin tuotantoa varten. Suunnitelmien valmiusaste ja yksityiskohtaisuus tulee sopia erikseen hankintaa ja tuotantoa varten, samoin kuin suunnitelmapakettien sisällöstä poikkeavat suunnitelmat. SUKE -projektissa laadittujen suunnitelmapakettien testaus suoritettiin case -tutkimuksena KOy Unioninkatu 20-22 sekä Riihimäen vankilan korjaushankkeille. Testauksessa havaittiin, että suunnitelmien ajoitus ja sisällöllinen jako toteutuivat melko hyvin suunnitelmapakettien mukaisesti. Suurimmat poikkeukset SUKE -paketeista olivat tilanjakosuunnitelmissa sekä tilavarusteiden suunnitelmissa. Tutkimuksen tuloksena laadittiin yrityskohtainen menettelyohje toteutussuunnittelun ohjaukseen, SUKE -pakettien mukainen ajoitettu suunnitelma- ja lähtötietoluettelo, suunnittelukatselmuksen muistiomalli sekä mallitaulukko suunnitteluvirheiden dokumentoimista varten.
  • Multichannel coherent receiver on the RTL-SDR
    (2019-03-11) Laakso, Mikko
     Sähkötekniikan korkeakoulu | Master's thesis
    A low cost multichannel coherent SDR receiver is studied in this thesis. The proposed design is based on the affordable RTL-SDR USB dongle. The synchronization method applied utilizes a common reference signal to coincide the sample streams from RTL-SDR receivers. The maximum number of channels successfully synchronized at 1 MHz sampling rate is 35. Furthermore, adding more channels is straightforward due to the modular structure of the system. Phase-coherent state can currently be reached up to approximately 1.5 GHz, or 85% of the tuning range of the dongle. A prototype receiver is evaluated by experimenting with MIMO space-time coding and direction of arrival estimation. Space-time coding was performed with differential block codes of dimensions 2 X 2 and 3 X 3. The transmissions are successfully received, displaying a clear BER performance increase as the number of receive antennas is increased to a maximum of 18. Direction of arrival estimates apply the MUSIC technique on signals from a 9-element uniform linear array. The results are promising, suggesting the receiver concept could be employed in low budget MIMO research.
  • Navigation and Object Manipulation in Collaborative VR Interior Design
    (2012) Laakso, Mikko
     School of Science | Doctoral dissertation (monograph)
    Virtual reality (VR) is a technologically created, immersive and interactive space. Interior design is an important profession where creative and technical solutions are applied to achieve a built environment. VR could be very beneficial in that area, but unfortunately most current solutions are just for viewing purposes. The main research question in this thesis is to find out how to create a simple immersive VR interior design system using a collaborative model? The problem is approached via constructive research method; a thorough literature survey along with the design, implementation and evaluation of a new immersive design system called VIDS. Creating VIDS requires studying both navigation and design elements. Three experiments with 16 users are conducted to evaluate different users’ navigation abilities with different tools. For designer user interface, VIDS uses collaborative design model with Wizard of Oz –type collaborative input. The user moves around the model inside the virtual room and makes design requests to the wizard, who is outside on a nearby computer and handles the actual model update. To determine how well immersive interior design can be performed using VIDS, 24 test subjects participate in a kitchen furnishing experiment. The experiment results show that VIDS and collaborative design approach seem to be very effective. The most important strengths are that it allows free movement, real-size view of the space and fast editing. It also promotes better space utilization, encourages practical collaboration and ensures that the working environment is always under total control. Weaknesses include the export/import delay caused by the chosen synchronization solution and the catalogue system that should be improved. Attributes of a practical immersive VR interior design system can be summarized. The system a) should provide the user with a realistic first-person perspective of the environment, b) should be embedded with an ergonomic, quick and practical way to move, c) should include some possibility to collaborate (e.g., simple tasks for user, complicated for the wizard), d) possible pre-defined catalogue should preferably be merged into the software and e) all design modifications should be visible to the user as soon as possible.
  • Near-field localization using machine learning: An empirical study
    (2021-04) Laakso, Mikko; Wichman, Risto
     A4 Artikkeli konferenssijulkaisussa
    Estimation methods for passive near-field localization have been studied to an appreciable extent in signal processing research. Such localization methods find use in various applications, for instance in medical imaging. However, methods based on the standard near-field signal model can be inaccurate in real-world applications, due to deficiencies of the model itself and hardware imperfections. It is expected that deep neural network (DNN) based estimation methods trained on the nonideal sensor array signals could outperform the model-driven alternatives. In this work, a DNN based estimator is trained and validated on a set of real world measured data. The series of measurements was conducted with an inexpensive custom built multichannel software-defined radio (SDR) receiver, which makes the nonidealities more prominent. The results show that a DNN based localization estimator clearly outperforms the compared model-driven method.
  • Normaalivoiman, taivutusmomentin ja vääntömomentin rasittama teräsbetoninen suorakaidepalkki
    (1971) Laakso, Mikko
     Helsinki University of Technology | Master's thesis
  • Phase-coherent multichannel SDR - Sparse array beamforming
    (2020) Laakso, Mikko; Rajamäki, Robin; Wichman, Risto; Koivunen, Visa
     A4 Artikkeli konferenssijulkaisussa
    We introduce a modular and affordable coherent multichannel software-defined radio (SDR) receiver and demonstrate its performance by direction-of-arrival (DOA) estimation on signals collected from a 7 X 3 element uniform rectangular array antenna, comparing the results between the full and sparse arrays. Sparse sensor arrays can reach the resolution of a fully populated array with reduced number of elements, which relaxes the required structural complexity of e.g. antenna arrays. Moreover, sparse arrays facilitate significant cost reduction since fewer expensive RF-IF front ends are needed. Results from the collected data set are analyzed with Multiple Signal Classification (MUSIC) DOA estimator. Generally, the sparse array estimates agree with the full array.
  • Practical Navigation in Virtual Architectural Environments
    (2001) Laakso, Mikko
     Helsinki University of Technology | Master's thesis
    Kiinnostus virtuaalitodellisuutta ja keinoympäristöjä kohtaan on jatkuvassa kasvussa. Keinoympäristöjen sovellukset kattavat laajan skaalan, peleistä liiketalouden suunnitteluun. Tämä työ keskittyy navigointiin luonnollisen tuntuisissa virtuaalimaailmoissa. Keinotekoisessa maailmassa navigoinnin tulisi olla käytännöllistä ja helppoa. Valitettavasti se on yleensä kaukana siitä - jostain syystä keinoympäristöjen käytettävyys on usein jätetty puolitiehen. Nykyisellään käyttäjän on helppo eksyä keinoympäristöön ja menettää täysin paikantajunsa. Tilanteen täytyy muuttua, jotta muutkin kuin vain alan asiantuntijat voivat navigoida virtuaalimaailmoissa. Kolmiulotteiset maailmat ja arkkitehtuurisovellukset vaativat uusia, intuitiivisia käyttöliittymiä joita tavallinen käyttäjäkin osaa hyödyntää. Tässä työssä pohdiskellaan virtuaaliympäristöissä navigointia sekä laitetekniseltä että teoriapohjaiselta kannalta. Työn teknologiaosuudessa esitellään virtuaalitodellisuuden mahdollistavia laitteistoja. Osuudessa kuvataan erilaisia näyttölaitteita, ohjausmenetelmiä sekä joitakin 3D-käyttöliittymien suunnitteluperiaatteita. Kirjallisuuskatsauksessa käsitellään navigaatioteorian pääkohtia. Navigoinnin kaksi osaa, liikkuminen (travel) sekä reitin etsintä (wayfinding) käydään läpi perinpohjaisesti. Suurimmat ongelmat on esitetty ja joitakin ratkaisuja sekä niihin liittyviä testituloksia kuvattu. Huomattava osa työstä koostuu uuden HCNav-navigointijärjestelmän kehityksen kuvauksesta. Järjestelmä rakennettiin käytettäväksi Teknillisen Korkeakoulun virtuaalihuoneessa. HCNav-järjestelmän tarkoituksena on tarjota käyttäjälle helppokäyttöinen ja intuitiivinen käyttöliittymä navigointiin. Kolme uutta ohjausmenetelmää testattiin. Nämä olivat ohjaussauva, datahanska sekä puheen tunnistus. Toinen tärkeä osa työstä on HCNav-järjestelmän tehokkuuden selvittäminen. Jotta saatiin selville tehostaako järjestelmä käyttäjien navigointia, oli tarpeellista suorittaa käytettävyystesti. Kaksitoista henkilöä osallistui testiin jossa HCNav-järjestelmää verrattiin perinteiseen navigointiohjelmaan jota virtuaalihuoneessa oltiin aikaisemmin käytetty. Koejärjestelyt on kuvattu ja tulokset analysoitu. Tulokset ovat lupaavia ja osoittavat että HCNav-järjestelmässä käyttöönotetut navigointimenetelmät ovat selkeästi aiempaa parempia.
  • Reliability Analysis of an Industrial Measurement Transmitter
    (2005) Holkkola, Maiju
     Helsinki University of Technology | Master's thesis
  • Trust Building in Supply Chains
    (2017) Laakso, Mikko
     School of Business | Master's thesis
    Holistic supply chain collaboration has appeared to be difficult to implement in strategic alliances due to managers’ lack of understanding the dynamics of trust-building. Too much reliance on technology and too little understanding of the nature of collaborative trust have led to a situation where strategic alliances often fail to thrive. This lack of awareness can be additionally observed in the supply chain literature: the concept of trust is covered without a profound scientific accuracy or clarity. In fact, views on trust are conflicting heavily even within the supply chain discipline. “Trust may be the most overused and abused word in the alliance lexicon.” (Fawcett et al. 2012). This thesis aims to fix this gap of knowledge; it establishes a holistic model of trust-building and studies the phenomenon from the perspective of several different disciplines such as cognitive science, sociology, microeconomics and psychology to build a profound background for the topic. The aim is to merge the supply chain use of the concept ‘trust’ with the mainstream of its meaning in other disciplines such as in cognitive science. The factors resulting in trust are additionally studied with an empirical questionnaire (n=220) for Finnish logistics experts. The results suggest that trust building in supply chains is explained by the knowledge-based theory of trust rather than the calculus-based theory. Neither asset specific investments nor contracting seem to have a high explanatory power for explaining trust in supply chain context. However, the time spent in a particular supply chain collaboration, the efficient use of tacit knowledge, extensive information sharing, partner’s reputation and the efficiency & seamlessness of the collaboration explain the existence of trust in supply chain collaboration. The calculus-based view on trust with its emphasis on transaction cost economics (TCE) is, therefore, an outdated view on supply chain management. Additionally, trust can be seen as a capital built on the norm of reciprocity and cooperative interaction. Trust is more easily lost than formed since the reciprocity norm punishes heavily those who exploit their trustors. Trust capital is created in a temporal context and accumulated through an iterative process, which takes time and requires the parties to learn about each other, in other words, to gather knowledge. A higher amount of trust capital allows people to trade and negotiate better terms in the context of commerce and trade. These results imply that trust-building in supply chains should be supported by corporate level policies, which encourage the creation of interpersonal relationships and collective learning between organizations. This requires trust. The findings suggest that the formation and use of highly complex tacit knowledge in supply chains allow the companies to form sustainable competitive advantages. Forming affinity groups provides an efficient way to make supply chains flourish through the accumulation of tacit knowledge and thus to increase the innovation capabilities and competitive advantages of the supply chain alliances.
  • Usability Issues in Virtual Environment Navigation
    (2004) Laakso, Mikko
     Helsinki University of Technology | Licentiate thesis