Aalto University

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    Disentangling the impact of temperature on consumers' attitudes toward nostalgic advertising

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    https://doi.org/10.1111/ijcs.12815Although the effect of temperature on consumers is ubiquitous, little is known about how temperature affects consumers' attitudes toward nostalgic advertising. Drawing on embodied cognition theory, this study explores the effect of temperature on consumers' attitudes toward nostalgic advertising through the mediator of the affective system. Based on two experiments involving personal and historical nostalgic advertising, our results show that when exposed to comfortable temperature, consumers follow the "assimilative effect" of temperature; warm temperatures trigger more positive attitudes toward nostalgic advertising when compared with cool temperatures. However, when exposed to uncomfortable temperatures, consumers follow the "complementary effect" of temperatures; cold temperatures lead to more positive attitudes toward nostalgic advertising than hot temperatures. Furthermore, the affective system plays a mediating role between temperature and consumers' attitudes toward nostalgic advertising. This study contributes to the literature on temperature in marketing and provides a practical guide for companies to implement nostalgic advertising strategies.Peer reviewe

    Microwave deicing properties and carbon emissions assessment of asphalt mixtures containing steel slag towards resource conservation and waste reuse

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    Funding Information: This work was supported by the National & Local Joint Engineering Research Center of Transportation and Civil Engineering Materials, Chongqing Jiaotong University (Grant number: TCEM-2023-02 ). Fan Zhang would like to thank Ruimeng Song (Chang'a University, China) for her assistance on laboratory experiments. Publisher Copyright: © 2023 The AuthorsA large amount of solid waste, such as steel slag (SS), is generated annually. At the same time, the shortage of road construction materials is becoming a concern. In this study, to recycle and reuse SS as a substitute for natural aggregates to achieve resource conservation and sustainable development of roads were conducted. First, the electromagnetic performance of SS was explored to evaluate its wave-absorbing properties. Next, the effect of different SS contents on heating properties, surface temperature, heating uniformity, and ice melting time (IMT) were investigated. Finally, the carbon emissions assessment (CEA) of conventional asphalt mixture (CAM) and steel slag asphalt mixture (SSAM) was compared. Results indicated that SS has ferromagnetic behavior and higher electromagnetic parameters, showing better wave-absorbing properties than limestone. There were three stages during microwave heating (MH): ice melting, moisture emitting, and stabilization. In addition, heating uniformity tends to be poor with the increase of SS, and samples with 100 % content of SS have the highest standard deviation of 21.04 °C and 20.77 °C after 270 s at −10 °C and − 20 °C. Samples containing 50 % SS have the best microwave deicing properties, which can reduce the IMT by 28.57 % to 46.18 % at different initial freezing temperatures and ice thickness compared to CAM. Furthermore, CEA revealed that CAM and SSAM's carbon emissions over road construction's life cycle are similar (around 27,000 kg) and originate mainly from the mixing and raw material extraction phases. However, SSAM leads to better environmental and economic benefits and provides an exemplary resource conservation and waste reuse solution.Peer reviewe

    Puuvillakankaiden hydrofobisointi: Biopohjaisen materiaalikäsittelyn ja kestävien vettähylkivien viimeistelyjen tehokkuuden arviointi

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    Cellulosic textiles inherently lack hydrophobic properties, often supplanted by synthetic, less recyclable multi-material solutions in barrier textiles. This thesis explores sustainable alternatives, specifically focusing on surface-modified hydrophobic cotton textiles. The study aims to prove the concept of hydrophobizing cotton textiles utilizing a novel bio-based material treatments to enhance hydrophobicity of commercial Durable Water Repellent (DWR) finishes. The efficacy of these treatments are assessed as is, post-abrasion and post-washing, thereby advancing towards a viable, sustainable solution in barrier textiles. The research evaluated four different DWR finishes on two cotton types (knitted and woven) across six structures. The finishes were applied using a conventional pad-dry-cure process. Select structures underwent additional treatment with a bio-based material treatment, prepared via same methods. The hydrophobic performance was primarily measured through sessile contact angle measurement of a water droplet, guided by a Design of Experiment (DOE) framework. Results indicated that the bio-based material treatment, enhanced hydrophobicity surpassing traditional DWR finishes in pre- and post-abrasion due to increased surface roughness. However, all samples showed reduced hydrophobicity after washing, with DWR-1 and DWR-2 losing effectiveness entirely, whereas DWR-3 and DWR-4 maintained hydrophobic properties post-washing. In conclusion, this study demonstrates the potential of bio-based material treatments in cellulosic textile finishing and creating functional, sustainable barrier textiles out of renewable resources. These findings hold significant implications for developing environmentally-friendly textiles in outerwear and reducing PFCs and synthetic materials in the industry.Selluloosatekstiilien vettähylkivät ominaisuudet jäävät heikommiksi verrattuna useisiin kierrätettäviin synteettisiin materiaaleihin barrieritekstiili-sovelluksissa. Tämä opinnäytetyö keskittyy kestävämpiin vaihtoehtoihin, joista erityisesti pintamuokattu puuvillakangas on tutkimuksen keskiössä. Työssä pyritään osoittamaan, miten uusi biomateriaalikäsittely parantaa kaupallisten vettä hylkivien kemikaalien (DWR) tehokkuutta tekstiilien märkäkäsittelyissä. Kemikaalien tehokkuutta arvioidaan sellaisenaan, hankauskäsittelyn jälkeen sekä viiden pesun jälkeen. Materiaalikeskiössä ovat neljä kaupallista DWR tuotetta, biopohjainen käsittely (BMT) sekä kaksi puuvillakangastyyppiä: kudos ja neulos, joista kummastakin valittiin kolme eri laatua. Kaikki kankaat käsiteltiin yleisesti käytetyllä rullatela-kyllästysmenetelmällä. Vettä hylkiviä ominaisuuksia arvioitiin vesipisaran kosketuskulma-mittauksilla, jotka toimivat tutkimusmuuttujina koesuunnittelussa (DOE). Tulokset osoittivat, että biopohjainen käsittely paransi kankaiden vettä hylkiviä ominaisuuksia verrattuna perinteiseen DWR-käsittelyyn, erityisesti hankauskäsittelyn aiheuttaman pinnan karheutumisen seurauksena. Kaikissa näytteissä vettä hylkivät ominaisuudet heikentyivät viiden pesun jälkeen. DWR-1 ja DWR-2 menettivät vettä hylkivät ominaisuutensa kokonaan, kun taas DWR-3 ja DWR-4 näytteissä ominaisuudet säilyivät pesujen jälkeen. Tämän opinnäytetyön tulokset korostavat biopohjaisen käsittelyn potentiaalia selluloosatekstiilien funktionalisoinnissa. Näiden tulosten valossa perfluorihiilivetyjen (PFC) sekä muovien käytön vähentäminen tekstiilialalla vaikuttaa mahdolliselta, mikä luo perustan kestävien, uusiutuvista materiaaleista valmistettujen ja kierrätettävien barrieritekstiilien kehitykselle muun muassa ulkoiluvaatteisiin

    Power system stability improvement through grid forming inverters for high penetration of grid following inverter scenarios.

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    The power transmission system is rapidly evolving into a renewable-dominated system due to the developments in the power sector and environ-mental benefits. The majority of the renewable power generation systems added to the power systems are either wind or solar power plants which use converters in the process of transferring the power from the generator to the grid. The converters currently used are called grid-following inverters where the support to the grid is minimal hence at the high share of converter-based resources, the system stability is an issue under disturbance. To overcome this issue, a novel concept called grid-forming inverters is in development to sup-port the grid. The research studies the limitations of the grid following inverter share that can be supported by the grid (transmission system hosting capacity) and the behaviours of the system under different fault conditions at high inverter-based resource shares. Furthermore, the effectiveness of using grid-forming inverters in different modes to maintain the stability of the power system in various power flow scenarios, location sensitivity of the grid-forming inverters to the stability, effect of series compensation at high inverter-based resource shares and achieving 100% inverter-based resource share using grid forming inverters is studied. The research used PSCAD software to simulate the scenarios and tow area Kundur network model was used as the base configuration and the model was modified with type 4 generic wind turbine and solar grid forming inverters. The main objectives of the research are, to identify the limitations of hosting capacity and the ability of grid-forming inverters to maintain system stability at high inverter-based resource shares under various conditions and disturb-ances and achieve 100% inverter-based resource share with the use of grid-forming inverters. The research objectives were achieved, and it suggests that achieving high inverter-based resource shares (up to 100%) is possible with the use of grid-forming inverters and different modes of grid-forming invert-ers have different effects on the system behaviour. Furthermore, the study shows that electromechanical oscillations can be dampened with sufficient shares and suitable modes of grid-forming inverters when connected to the required locations

    Suurten hybridiaurinkolämpöjärjestelmien analyysi​

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    In the thesis, heat pumps were studied as part of large scale solar thermal plants. The goal was to compare different heat pump models and optimize their use in solar thermal plants. For optimization, a calculation tool was developed in MS Excel. Working principle of solar power plants and some methods of energy storage were reviewed in the thesis. The operating principle of heat pumps, different heat pump types and refrigerant options for them were presented. Two different calculation tools were created with Excel, one of which was chosen for deeper development. The selected calculation tool was used to compare two different cases where the heat pump is connected as part of the solar thermal plant. It was found that the calculation tool works relatively well in the specific cases, but it requires more different types of heat pumps on it. Cost estimates for different options are not currently included in the calculation tool. This should be considered when using the calculation tool, because the most efficient heat pump is not always the cheapest one.Diplomityössä tutkittiin lämpöpumppuja osana suuria aurinkolämpövoimalaitoksia. Tavoitteena oli vertailla eri lämpöpumppuratkaisuja ja optimoida niiden käyttö aurinkolämpövoimalaitoksissa. Optimointia varten kehitettiin laskentatyökalu MS Excelissä. Työssä käytiin läpi aurinkovoimalaitosten toimintaperiaate ja muutamia energian varastointi tapoja. Lämpöpumpuista esiteltiin toimintaperiaate, eri lämpöpumpputyyppejä ja kylmäainevaihtoehtoja, Excelillä luotiin kaksi eri laskentatyökalua, joista toinen valittiin pidempään kehitykseen. Valitulla laskentatyökalulla vertailtiin kahta eri tapausta, joissa lämpöpumppu on liitetty osaksi aurinkolämpövoimalaitosta. Tuloksissa todettiin laskentatyökalun toimivan suhteellisen hyvin kyseissisä tapauksissa, mutta sen vaativan vielä useamman eri lämpöpumpputyypin lisäämistä siihen. Laskentatyökaluun ei tällä hetkellä ole myöskään lisättynä kustannusarvioita eri vaihtoehdoille. Tämä tulee ottaa huomioon laskentatyökalua käytettäessä, koska todellisuudessa tehokkuuden lisäksi valintaan vaikuttaa kustannukset

    Ostoskeskuksissa syntyvien sivuvirtojen hyödyntäminen hiilen ja ravinteiden lähteenä kasvisolukasvatuksille

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    Current food production capacity with only conventional agriculture is not suf-ficient to solely sustain the food demand for increasing human population. Sufficient food production could be enabled by combining conventional farm-ing with cellular agriculture. Cellular agriculture refers to the production of agricultural commodities with plant, microbial and animal cells. Cellular agri-culture, such as single cell protein synthesis, could also reduce the food pro-duction associated burden to land use and climate of food in the future. How-ever, applications in cellular agriculture comes with many challenges, one of which includes the high costs for growth medium components. The aim of this thesis was to utilize alternative sources for carbon and nutrients for the plant cell growth medium to reduce costs. The alternative sources assessed in this thesis included biodegradable side streams from shopping centre environ-ment. There, side streams accumulate from food courts and markets and could include orange peels, soda drink waste mix, expired bread, spent coffee grounds and brewer’s spent grains. Urine was also considered as a potential nutrient source since it possesses many valuable compounds that are required for the growth of plant cells. Future efficient purification technologies could permit the food regulation to allow the use of urine as a nutrient source. Plant cells require carbon and nutrients in a soluble form, therefore pre-treatments were applied for solid side streams to release monosaccharides from longer polysaccharide chains. The utilization potential of the side streams was evaluated by using them as culture medium components for cul-tivations of three non-taxonomically related plant cell lines: arctic bramble, tobacco BY-2, and barley. The side stream suitability was assessed by using biomass production after a cultivation period as a scale for comparison. Soda drink waste mix and synthetic urine contributed for the highest biomass con-centrations, which was used as a measure for growth. These side streams were used as main components for optimization of growth media composition. Both side streams were successfully utilized for cultivations, especially for arc-tic bramble with notable increase in biomass concentration. Side streams were found to be potential culture medium components for plant cell cultures but notable differences in growth and growth behaviour be-tween the studied plant cell lines were observed. The appliance of thus far unutilized side steams would enhance the circular economy and improve the food value chain. In addition, the economical sustainability of production would improve as costly components would be replaced with unutilized sources.Nykyiset maanviljely- ja ruoantuotantomenetelmät eivät yksinään pysty tuot-tamaan tarpeeksi ruokaa kasvavan väkiluvun ruokatarpeisiin. Solumaatalou-den avulla voitaisiin osittain täydentää ruoantuotannon riittämättömyyttä tu-levaisuudessa kasvattamalla kasvi-, mikrobi- ja eläinsolujen avulla ruoka-aineita. Määrän lisääminen proteiinien, ja muiden raaka-aineiden tuotannos-sa solumaatalouden avulla voisi pienentää nykyisen maatalouden kuormitusta ja mahdollistaa ruoan riittävyyden. Solumaatalouden kehitystyön haasteina ovat kuitenkin korkeat kasvatusalustan ja siten tuotannon kustannukset. Täs-sä työssä tutkittiin kasvualustan ravinteiden ja hiilen lähteen korvaamista os-toskeskuksissa syntyvillä sivuvirroilla ja tavoitteena oli alentaa kasvatusalus-tan kustannuksia. Tutkittavia ruokaperäisiä sivuvirtoja olivat esimerkiksi ap-pelsiinin kuoret, virvoitusjuomajäte, vanhentunut leipä, kahvinporot ja oluen tuotannosta syntyvä mäski. Tässä työssä tutkittiin myös ihmisvirtsaa mahdol-lisena ravinteiden lähteenä, koska se sisältää kasvisolujen kasvulle tärkeitä yhdisteitä. Vaikka virtsaa ei voida vielä hyödyntää sivuvirtana nykyisten sää-dösten takia, tulevaisuudessa sen hyödyntäminen voisi kuitenkin olla mahdol-lista tehokkaampien suodatus- ja puhdistusmenetelmien ansiosta. Ruokaperäisten kiinteiden sivuvirtojen hyödyntäminen edellytti esikäsittely-jä, jotta niiden sisältämät sokerit ja ravinteet saatiin kasvisoluille hyödynnet-tävään liukoiseen muotoon. Esikäsittelyiden tarkoitus oli hajottaa sivuvirtojen sisältämiä pidempiä polysakkarideja lyhyemmiksi monosakkarideiksi. Sivuvir-tojen soveltuvuutta kasvatusalustan eri komponentteina arvioitiin kasvisolu-jen biomassan tuotannolla. Työssä tutkittiin mesimarjan, tupakan, ja ohran kasvisolulinjojen välisiä eroja sivuvirtojen hyödyntämisessä. Kasvisolulinjat ja sivuvirrat, jotka mahdollistivat parhaimman kasvun, valittiin osaksi kasva-tusalustan optimointia. Limujätteen ja synteettisen virtsan yhdistelmää hyö-dynnettiin onnistuneesti erityisesti mesimarjan kasvatusalustassa. Tutkimustulokset osoittivat, että sivuvirtojen hyödyntämismahdollisuudet osana kasvatusalustaa ravinteiden ja hiilen lähteinä ovat hyvät. Tehtyjen kas-vatuskokeiden perusteella kasvisolujen välillä ilmeni eroja kasvukäyttäytymi-sessä ja biomassan tuotannossa. Sivuvirtojen käyttö mahdollistaisi uusien so-lumaatalouden sovellusten kestävämmän kehittämisen, sekä kiertotalouden edistämisen lisäämällä materiaalien kokonaisvaltaista kierrätystä

    Reinforcement Learning Methodologies for RAN Slicing

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    The rapid development of Radio Access Networks (RANs) from 1G to 5G has revolutionized telecommunications, ushering the world in a new era of connectivity. As a key component of the mobile network, RAN plays a crucial role in providing internet access to all personal devices, shaping the modern digital landscape. However, the increasing demand for a wide range of customer needs poses yet another challenge in the journey towards 5G and beyond. RAN Slicing addresses the performance bottleneck of RAN, substantially impacting user experience in terms of throughput, latency, and reliability. It utilizes virtualization to divide radio resources into separate, autonomous virtual networks, assigning resources dynamically to satisfy service requirements. The dynamic nature of RAN slicing requires innovative solutions. Deep Reinforcement Learning (DRL) agents have emerged as a solution to solve complex tasks that need complete automation. These agents adaptively distribute resources to network slices in response to changing factors, including channel quality, slice admission, service level agreements, and user density. This thesis builds upon prior research by addressing two key challenges in DRL algorithms: slow convergence and unstable exploration phases. The results emphasise the critical role of reward function selection and hyper-parameter tuning. A new reward function that outperforms previous approaches is introduced. Multiple algorithms are evaluated, with the Advantage Actor Critic one exhibiting superior performance in several cases. Furthermore, the significance of policy transfer is highlighted, whereby an expert base station’s policy is transferred to a learner base station using policy reuse, distillation, or a hybrid approach. This study confirms that these transfers accelerate convergence, with policy distillation and the hybrid approach demonstrating notable reliability

    Nudgo: An interactive system for neuro-diverse social connections

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    This thesis presents the design and testing of a system called the Nudgo system to support the connection building between autistic children and neurotypical adults. Our objective in this research is to create a system that can provide assistance for interactions between autistic children and neurotypical adults, making it easier for them to establish rapport and intimacy and solve the double empathy problem. The embodied and enactive cognition, especially the participatory sensemaking theory, lay the foundation for analysing and modelling interpersonal connections in this project. To enhance the research and design process of this project, I em-ploy the Research through Design (RtD) method. The system undergoes iterative design and refinement across multiple cycles. The whole process is divided into five activities: ideation, design, implementation, workshop, and theory development. Additionally, A combination of User-centered Design (UCD) and Co-design approaches is adopted in workshop activities to better engage target users in the design process. The main outcomes of the research are early prototypes of the Nudgo system, one in wall form and one in tunnel form. These prototypes, com-bined with workshop observations, provide invaluable insights and future guide-lines for the design of the final product. Moreover, the design concept and valida-tion have effectively addressed the majority of the key research questions present-ed in the thesis. The strategies outlined in this research can readily be applied to other RtD projects with similar interests. In the discussion section, sincere suggestions were also proposed for projects advanced using the RtD method in this study

    Systems perspective reveals interconnections in nitrogen and phosphorus flows

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    | openaire: EC/H2020/819202/EU//SOS.aquaterra Funding Information: Work was funded by Academy of Finland (project TREFORM; grant number 339834) and the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (project SOS.aquaterra; grant number 819202).Non peer reviewe

    Optimizing the Performance of Text Classification Models by Improving the Isotropy of the Embeddings using a Joint Loss Function

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    Recent studies show that the spatial distribution of the sen- tence representations generated from pre-trained language models is highly anisotropic. This results in a degradation in the performance of the models on the downstream task. Most methods improve the isotropy of the sentence embeddings by refining the corresponding contextual word representations, then deriving the sentence embeddings from these refined representations. In this study, we propose to improve the quality of the sentence embeddings extracted from the [CLS] token of the pre- trained language models by improving the isotropy of the embeddings. We add one feed-forward layer between the model and the downstream task layers, and we train it using a novel joint loss function. The pro- posed approach results in embeddings with better isotropy, that gener- alize better on the downstream task. Experimental results on 3 GLUE datasets with classification as the downstream task show that our pro- posed method is on par with the state-of-the-art, as it achieves perfor- mance gains of around 2–3% on the downstream tasks compared to the baseline.Peer reviewe


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