Aaltodoc Repository :: Browsing by Department "University of Turku"

Browsing by Department "University of Turku"

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Aalto-1, multi-payload CubeSat: Design, integration and launch
(Elsevier Limited, 2021-10) Praks, Jaan; Mughal, M. Rizwan; Vainio, R.; Janhunen, P.; Envall, J.; Oleynik, P.; Näsilä, A.; Leppinen, H.; Niemelä, P.; Slavinskis, A.; Gieseler, J.; Toivanen, P.; Tikka, T.; Peltola, T.; Bosser, A.; Schwarzkopf, G.; Jovanovic, N.; Riwanto, B.; Kestilä, A.; Punkkinen, A.; Turku, University; Hedman, H.-P.; Lill, J.-O.; Slotte, J.M.K.; Kettunen, H.; Virtanen, A.; Department of Electronics and Nanoengineering; Jaan Praks Group; University of Turku; Finnish Meteorological Institute; VTT Technical Research Centre of Finland; Åbo Akademi; University of Jyväskylä
The design, integration, testing and launch of the first Finnish satellite Aalto-1 is briefly presented in this paper. Aalto-1, a three-unit CubeSat, launched into Sun-synchronous polar orbit at an altitude of approximately 500 km, is operational since June 2017. It carries three experimental payloads: Aalto Spectral Imager(AaSI), Radiation Monitor (RADMON) and Electrostatic Plasma Brake (EPB). AaSI is a hyperspectral imager in visible and near-infrared (NIR) wavelength bands, RADMON is an energetic particle detector and EPB is a de-orbiting technology demonstration payload. The platform was designed to accommodate multiple payloads while ensuring sufficient data, power, radio, mechanical and electrical interfaces. The design strategy of platform and payload subsystems consists of in-house development and commercial subsystems. The CubeSat Assembly, Integration & Test (AIT) followed Flatsat-Engineering-Qualication Model (EQM)-Flight Model (FM) model philosophy for qualification and acceptance. The paper briefly describes the design approach of platform and payload subsystems, their integration and test campaigns and spacecraft launch. The paper also describes the ground segment & services that were developed by Aalto-1 team.
Accurate calibration scheme for a multi-camera mobile mapping system
(Multidisciplinary Digital Publishing Institute (MDPI), 2019-12-01) Khoramshahi, Ehsan; Campos, Mariana Batista; Tommaselli, Antonio Maria Garcia; Vilijanen, Niko; Mielonen, Teemu; Kaartinen, Harri; Kukko, Antero; Honkavaara, Eija; University of Helsinki; São Paulo State University; Finnish Geospatial Research Institute; National Land Survey of Finland; University of Turku; MeMo; Department of Built Environment
Mobile mapping systems (MMS) are increasingly used for many photogrammetric and computer vision applications, especially encouraged by the fast and accurate geospatial data generation. The accuracy of point position in an MMS is mainly dependent on the quality of calibration, accuracy of sensor synchronization, accuracy of georeferencing and stability of geometric configuration of space intersections. In this study, we focus on multi-camera calibration (interior and relative orientation parameter estimation) and MMS calibration (mounting parameter estimation). The objective of this study was to develop a practical scheme for rigorous and accurate system calibration of a photogrammetric mapping station equipped with a multi-projective camera (MPC) and a global navigation satellite system (GNSS) and inertial measurement unit (IMU) for direct georeferencing. The proposed technique is comprised of two steps. Firstly, interior orientation parameters of each individual camera in an MPC and the relative orientation parameters of each cameras of the MPC with respect to the first camera are estimated. In the second step the offset and misalignment between MPC and GNSS/IMU are estimated. The global accuracy of the proposed method was assessed using independent check points. A correspondence map for a panorama is introduced that provides metric information. Our results highlight that the proposed calibration scheme reaches centimeter-level global accuracy for 3D point positioning. This level of global accuracy demonstrates the feasibility of the proposed technique and has the potential to fit accurate mapping purposes.
Acquisition of supply market intelligence – An information processing perspective
(ELSEVIER SCI LTD, 2020-12) Lorentz, Harri; Aminoff, Anna; Kaipia, Riikka; Pihlajamaa, Matti; Ehtamo, Jesse; Tanskanen, Kari; University of Turku; Hanken School of Economics; Department of Industrial Engineering and Management; VTT Technical Research Centre of Finland
The capability to develop and sustain superior knowledge of markets and supply chains, or supply market intelligence (SMI), is an important element in increasing the strategic relevance of purchasing and supply management (PSM). This study draws on information processing theory (IPT) to shed light on how firms acquire SMI. In particular, the study aims to identify the drivers and mechanisms of information processing in SMI acquisition and to explore how the two constructs are related. Our findings emerged from an abductive multiple case study including 22 SMI tasks in eight case companies operating in various manufacturing industries. We find that the drivers of information processing needs in SMI acquisition are related either to uncertainty or equivocality. Uncertainty describes a situation in which decision-makers may be ignorant of a variable's value while equivocality describes a situation in which they may be ignorant of the variable's existence. We identify four structural mechanisms and three information technology mechanisms for information processing in the SMI context. We also find that equivocality seems to trump uncertainty in determining the use of the identified SMI acquisition mechanisms. In addition to elaborating IPT in the SMI context and exploring the theoretical foundations of SMI, we offer practitioners a framework for supporting the design of SMI practices in procurement organisations.
Adult learners and a one-day production training – Small changes but the native language sound system prevails
(2017-01-16) Peltola, Kimmo U.; Rautaoja, Tomi; Alku, Paavo; Peltola, Maija S.; University of Turku; Dept Signal Process and Acoust
Allometry in the corpus callosum in neonates: Sexual dimorphism
(JOHN WILEY & SONS, 2022-10-15) Lewis, John D.; Acosta, Henriette; Tuulari, Jetro J.; Fonov, Vladimir S.; Collins, D. Louis; Scheinin, Noora M.; Lehtola, Satu J.; Rosberg, Aylin; Lidauer, Kristian; Ukharova, Elena; Saunavaara, Jani; Parkkola, Riitta; Lähdesmäki, Tuire; Karlsson, Linnea; Karlsson, Hasse; McGill University; University of Marburg; University of Turku; Department of Neuroscience and Biomedical Engineering
The corpus callosum (CC) is the largest fiber tract in the human brain, allowing interhemispheric communication by connecting homologous areas of the two cerebral hemispheres. In adults, CC size shows a robust allometric relationship with brain size, with larger brains having larger callosa, but smaller brains having larger callosa relative to brain size. Such an allometric relationship has been shown in both males and females, with no significant difference between the sexes. But there is some evidence that there are alterations in these allometric relationships during development. However, it is currently not known whether there is sexual dimorphism in these allometric relationships from birth, or if it only develops later. We study this in neonate data. Our results indicate that there are already sex differences in these allometric relationships in neonates: male neonates show the adult-like allometric relationship between CC size and brain size; however female neonates show a significantly more positive allometry between CC size and brain size than either male neonates or female adults. The underlying cause of this sexual dimorphism is unclear; but the existence of this sexual dimorphism in neonates suggests that sex-differences in lateralization have prenatal origins.
Analysis of airport design for introducing infrastructure for autonomous drones
(Emerald, 2023) Edelman, Harry; Stenroos, Joel; Peña Queralta, Jorge; Hästbacka, David; Oksanen, Jani; Westerlund, Tomi; Röning, Juha; Tampere University; University of Turku; Department of Neuroscience and Biomedical Engineering; University of Oulu; Department of Neuroscience and Biomedical Engineering
Purpose: Connecting autonomous drones to ground operations and services is a prerequisite for the adoption of scalable and sustainable drone services in the built environment. Despite the rapid advance in the field of autonomous drones, the development of ground infrastructure has received less attention. Contemporary airport design offers potential solutions for the infrastructure serving autonomous drone services. To that end, this paper aims to construct a framework for connecting air and ground operations for autonomous drone services. Furthermore, the paper defines the minimum facilities needed to support unmanned aerial vehicles for autonomous logistics and the collection of aerial data. Design/methodology/approach: The paper reviews the state-of-the-art in airport design literature as the basis for analysing the guidelines of manned aviation applicable to the development of ground infrastructure for autonomous drone services. Socio-technical system analysis was used for identifying the service needs ofdrones. Findings: The key findings are functional modularity based on the principles of airport design applies to micro-airports and modular service functions can be connected efficiently with an autonomous ground handling system in a sustainable manner addressing the concerns on maintenance, reliability and lifecycle. Research limitations/implications: As the study was limited to the airport design literature findings, the evolution of solutions may provide features supporting deviating approaches. The role of autonomy and cloud-based service processes are quintessentially different from the conventional airport design and are likely to impact real-life solutions as the area of future research. Practical implications: The findings of this study provided a framework for establishing the connection between the airside and the landside for the operations of autonomous aerial services. The lack of such framework and ground infrastructure has hindered the large-scale adoption and easy-to-use solutions for sustainable logistics and aerial data collection for decision-making in the built environment. Social implications: The evolution of future autonomous aerial services should be accessible to all users, “democratising” the use of drones. The data collected by drones should comply with the privacy-preserving use of the data. The proposed ground infrastructure can contribute to offloading, storing and handling aerial data to support drone services’ acceptability. Originality/value: To the best of the authors’ knowledge, the paper describes the first design framework for creating a design concept for a modular and autonomous micro-airport system for unmanned aviation based on the applied functions of full-size conventional airports.
Analysis of pandemic outdoor recreation and green infrastructure in Nordic cities to enhance urban resilience
(Nature Publishing Group, 2022-10-03) Fagerholm, Nora; Samuelsson, Karl; Eilola, Salla; Giusti, Matteo; Hasanzadeh, Kamyar; Kajosaari, Anna; Koch, Daniel; Korpilo, Silviya; Kyttä, Marketta; Legeby, Ann; Liu, Yu; Præstholm, Søren; Raymond, Christopher; Rinne, Tiina; Olafsson, Anton Stahl; Barthel, Stephan; University of Turku; University of Gävle; Planning and Transportation; KTH Royal Institute of Technology; University of Helsinki; University of Copenhagen; Department of Built Environment
Recent empirical research has confirmed the importance of green infrastructure and outdoor recreation to urban people’s well-being during the COVID-19 pandemic. However, only a few studies provide cross-city analyses. We analyse outdoor recreation behaviour across four Nordic cities ranging from metropolitan areas to a middle-sized city. We collected map-based survey data from residents (n = 469–4992) in spring 2020 and spatially analyse green infrastructure near mapped outdoor recreation sites and respondents’ places of residence. Our statistical examination reveals how the interplay among access to green infrastructure across cities and at respondents’ residential location, together with respondents’ socio-demographic profiles and lockdown policies or pandemic restrictions, affects outdoor recreation behaviour. The results highlight that for pandemic resilience, the history of Nordic spatial planning is important. To support well-being in exceptional situations as well as in the long term, green infrastructure planning should prioritise nature wedges in and close to cities and support small-scale green infrastructure.
Annea muistaen
(Yhdyskuntasuunnittelun Seura ry., 2019-12-23) Ilmonen, Mervi; Ruoppila, Sampo; Rakennetun ympäristön laitos; University of Turku
”Another visitor!” – kun puhuvat koneet tulivat kotiin
(LÄHIKUVA-YHDISTYS, 2020-04-09) Joelsson, Tapani; Reunanen, Markku; University of Turku; Median laitos
In this article we focus on speech produced by 8- and 16-bit home computers during their "golden era", the 1980s and the beginning of the 1990s. Over this period budget-friendly home computers spread to Finnish homes, and an increasing number of citizens ended up in contact with computing. Our research material has been collected using an online survey, where we asked about first remembrances about talking machines and the feelings evoked by those encounters. The memories revolve around topics such as home computers of the time, their games and the emerging computer hobby culture. Naturally, movies and TV series of the time period, which created expectations about the capabilities of computers, are also present in the memories. The responses show some signs of a strengthened relationship with the machine, but the most predominant themes are the positive experiences created by a talking machine and the increased faith for the future. Experiments by young hobbyists were often unexpected and ingenious, which on the one hand tells about their open-minded attitude towards technology, and on the other hand about the lack of established uses for talking machines.
Autonomous corrosion assessment of reinforced concrete structures : Feasibility study
(Multidisciplinary Digital Publishing Institute (MDPI), 2020-12-01) Taffese, Woubishet Zewdu; Nigussie, Ethiopia; Structures – Structural Engineering, Mechanics and Computation; University of Turku; Department of Civil Engineering
In this work, technological feasibility of autonomous corrosion assessment of reinforced concrete structures is studied. Corrosion of reinforcement bars (rebar), induced by carbonation or chloride penetration, is one of the leading causes for deterioration of concrete structures throughout the globe. Continuous nondestructive in-service monitoring of carbonation through pH and chloride ion (Cl−) concentration in concrete is indispensable for early detection of corrosion and making appropriate decisions, which ultimately make the lifecycle management of RC structures optimal from resources and safety perspectives. Critical state-of-the-art review of pH and Cl− sensors revealed that the majority of the sensors have high sensitivity, reliability, and stability in concrete environment, though the experiments were carried out for relatively short periods. Among the reviewed works, only three attempted to monitor Cl− wirelessly, albeit over a very short range. As part of the feasibility study, this work recommends the use of internet of things (IoT) and machine learning for autonomous corrosion condition assessment of RC structures.
Behavioral reasoning perspectives on organic food purchase
(Academic Press Inc., 2020-11-01) Tandon, Anushree; Dhir, Amandeep; Kaur, Puneet; Kushwah, Shiksha; Salo, Jari; University of Turku; Lappeenranta University of Technology; North West University; NTPC School of Business; University of Helsinki
Consumers' rising interest in organic food has drawn the attention of the academic community. The literature on the topic is growing, but it mostly focuses either on the acceptance of or resistance toward organic food. However, marketing scholars argue that the development of more in-depth insights into consumers’ reasoning processes, and especially the roles of values and context-specific reasons are needed. The present study bridges this gap by utilizing the novel behavioral reasoning theory (BRT) framework. Cross-sectional data from 307 consumers and non-consumers from India were collected to investigate associations among attitudes, reasoning, value, and purchase intentions. This research studies the moderating role of food safety concerns and buying involvement. Additionally, the mediating role of reasons and attitudes is examined. The results suggest that value was positively associated with reasons (for and against), whereas attitude and reasons (for) resulted in favorable purchase intentions. Reasons (for and against) fully mediate the association between value and attitude. Furthermore, attitude partially mediates the association of reasons and purchase intentions. The moderation effect was not found for food safety concerns, but a limited effect among studied associations was observed for buying involvement. The findings raise significant implications for marketers and policymakers.
A bi-criteria moving-target travelling salesman problem under uncertainty
(Elsevier, 2023-08-16) Maskooki, Alaleh; Kallio, Markku; University of Turku; Department of Information and Service Management
This article concerns a variant of moving target travelling salesman problem where the number and locations of targets vary with time and realizations of random trajectories. Managerial objectives are to maximize the number of visits to different targets and to minimize the total travel distance. Employing a linear value function for finding supported Pareto-efficient solutions, we develop a two-stage stochastic programming model. We propose an iterative randomized dynamic programming (RDP) algorithm which converges to a global optimum with probability one. Each iteration in RDP involves a randomized backward and forward recursion stage as well as options for improving any given schedule: swaps of targets and optimization of timing for visits. An integer linear programming (ILP) model is developed and solved by a standard ILP solver to evaluate the performance of RDP on instances of real data for scheduling an environmental surveillance boat to visit ships navigating in the Baltic Sea. Due to a huge number ofbinary variables, the ILP model in practice becomes intractable. For small to medium size data sets, the Pareto-efficiency of solutions found by RDP and ILP solver are equal within a reasonable tolerance; however, RDP is significantly faster and able to deal with large-scale problems in practice.
Biomonitoring of Indoor Air Fungal or Chemical Toxins with Caenorhabditis elegans nematodes
(MDPI AG, 2023-02) Paavanen-Huhtala, Sari; Kalichamy, Karunambigai; Pessi, Anna-Mari; Häkkilä, Sirkku; Saarto, Annika; Tuomela, Marja; Andersson, Maria A.; Koskinen, Päivi J.; University of Turku; Osuuskunta Bionautit; Performance in Building Design and Construction; Department of Civil Engineering
Bad indoor air quality due to toxins and other impurities can have a negative impact on human well-being, working capacity and health. Therefore, reliable methods to monitor the health risks associated with exposure to hazardous indoor air agents are needed. Here, we have used transgenic Caenorhabditis elegans nematode strains carrying stress-responsive fluorescent reporters and evaluated their ability to sense fungal or chemical toxins, especially those that are present in moisture-damaged buildings. Liquid-based or airborne exposure of nematodes to mycotoxins, chemical agents or damaged building materials reproducibly resulted in time- and dose-dependent fluorescent responses, which could be quantitated by either microscopy or spectrometry. Thus, the C. elegans nematodes present an easy, ethically acceptable and comprehensive in vivo model system to monitor the response of multicellular organisms to indoor air toxicity.
Bittivainajien pikselikalmistot – hautaamisen ja suremisen rooli digitaalisissa peleissä
(2019-12-18) Joelsson, Tapani; Reunanen, Markku; University of Turku; Median laitos; Arjoranta, Jonne; Friman, Usva; Koskimaa, Raine; Mäyrä, Frans; Sotamaa, Olli; Suominen, Jaakko
Digitaalisissa peleissä kuolemaa käytetään niin narratiivisena kuin pelimekaanisenakin elementtinä; mekaniikan kannalta vihollisten tai oman hahmon kuolema kertoo tyypillisesti suorituksen onnistumisesta tai epäonnistumisesta. Kuoleman seuraamukset, kuten hautaaminen ja sureminen, ovat puolestaan esillä paljon vaihtelevammin. Tässä tutkimuksessa tarkastellaan bittivainajien matkaa kuoleman hetkestä viimeiseen leposijaansa pikselikalmistossa. Materiaalina käytettyjä pelejä lähestyttiin lähiluvun kautta, muodostaen kolme pääteemaa: Kuoleminen, Hautaaminen ja hautapaikat, sekä Sureminen pelimaailman sisällä. Löydösten perusteella voidaan ymmärtää kuoleman roolia pelisuunnittelussa: niin tarinankerronnassa, pelimekaniikassa kuin visuaalisessa esityksessäkin. Artikkeli avaa pelitutkimusta kuoleman tutkimuksen suuntaan tuoden peleissä usein trivialisoituun aiheeseen uutta näkökulmaa.
Bose-Hubbard lattice as a controllable environment for open quantum systems
(2018-04-09) Cosco, Francesco; Borrelli, Massimo; Mendoza-Arenas, Juan José; Plastina, Francesco; Jaksch, Dieter; Maniscalco, Sabrina; University of Turku; Universidad de los Andes Colombia; University of Calabria; University of Oxford; Centre of Excellence in Quantum Technology, QTF; Department of Applied Physics
We investigate the open dynamics of an atomic impurity embedded in a one-dimensional Bose-Hubbard lattice. We derive the reduced evolution equation for the impurity and show that the Bose-Hubbard lattice behaves as a tunable engineered environment allowing one to simulate both Markovian and non-Markovian dynamics in a controlled and experimentally realizable way. We demonstrate that the presence or absence of memory effects is a signature of the nature of the excitations induced by the impurity, being delocalized or localized in the two limiting cases of a superfluid and Mott insulator, respectively. Furthermore, our findings show how the excitations supported in the two phases can be characterized as information carriers.
Calibration of RADMON radiation monitor onboard Aalto-1 CubeSat
(ELSEVIER SCI LTD, 2020-07-01) Oleynik, Philipp; Vainio, Rami; Punkkinen, Arttu; Dudnik, Oleksiy; Gieseler, Jan; Hedman, Hannu Pekka; Hietala, Heli; Hæggström, Edward; Niemelä, Petri; Peltonen, Juhani; Praks, Jaan; Punkkinen, Risto; Säntti, Tero; Valtonen, Eino; University of Turku; NASU - Institute of Radio Astronomy; University of Helsinki; Department of Electronics and Nanoengineering
RADMON is a small radiation monitor designed and assembled by students of University of Turku and University of Helsinki. It is flown on-board Aalto-1, a 3-unit CubeSat in low Earth orbit at about 500 km altitude. The detector unit of the instrument consists of two detectors, a Si solid-state detector and a CsI(Tl) scintillator, and utilizes the ΔE-E technique to determine the total energy and species of each particle hitting the detector. We present the results of the on-ground and in-flight calibration campaigns of the instrument, as well as the characterization of its response through extensive simulations within the Geant4 framework. The overall energy calibration margin achieved is about 5%. The full instrument response to protons and electrons is presented and the issue of proton contamination of the electron channels is quantified and discussed.
Capacity and security of heterogeneous distributed storage systems
(2013) Ernvall, Toni; El Rouayheb, Salim; Hollanti, Camilla; Poor, Vincent; University of Turku; Algebra and Discrete Mathematics; Department of Mathematics and Systems Analysis
Changing patterns of social media use? A population-level study of Finland
(SPRINGER HEIDELBERG, 2020-08) Koiranen, Ilkka; Keipi, Teo; Räsänen, Pekka; Koivula, Aki; University of Turku; Design Factory
This article examines the changing patterns of Finnish social media use during the years 2008–2016. This is the first temporal look at changes in Finnish social media use with representative population-level data. We assess how social media use has evolved between socio-economic and demographic groups in advanced information societies, with a focus on Finland. We also look at how demographic factors associate with use purposes of social media. The target of empirical analysis is on social media use and use purposes by gender, age, education level and area of residence. The data come from nationally representative and temporally comparable surveys focusing on adult populations. Findings show that the effect of socio-demographic factors on overall use and different use purposes of social media persists. Furthermore, the results seem to show a diminishing of the socializing impact of social media; on the other hand, individual, commercial and goal-oriented use practices seem to have become a major focus of social media use.
Clearing the paradigmatic fog
(Elsevier Science Inc., 2023-08) Möller, Kristian; Halinen, Aino; Department of Marketing; University of Turku; Department of Marketing
Collective consciousness in business ecosystems
(RWTH Aachen University, 2018-01-15) Turunen, Marja; Mäntymäki, Matti; Department of Industrial Engineering and Management; University of Turku; Hyrynsalmi, Sami; Suominen, Arho; Jud, Christopher; Wang, Xiaofeng; Bosch, Jan; Münch, Jürgen
This paper presents collective consciousness as a lens through which to analyze the psycho-social dynamics of business ecosystems. While the business ecosystem concept has drawn a lot of attention in software and business literature, the intangible psycho-social layers of attention and shared cognition produced by the interactions between ecosystem actors are not well understood. To address this void in the literature, we adopt collective consciousness as a conceptual tool to better understand business ecosystems as complex networks of heterogeneous actors. We present an illustrative case of an emerging business ecosystem of digital services for real estate and facility management and scrutinize the applicability of collective consciousness as a conceptual device to better understand the characteristics and dynamics of business ecosystems. We suggest that employing collective consciousness provides a useful analytical device to better understand the complexities emerging from the interactions between the actors. We further discuss under what circumstances employing collective consciousness as a conceptual tool adds particular value for business ecosystem research and practice.

Browsing by Department "University of Turku"

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