Pushover-analyysin sovellettavuus seismisessä teräsrakennesuunnittelussa

The objective of this master’s thesis was to gain knowledge about an advanced seismic analysis method, pushover analysis, and to study its applicability in seismic steel structure design. The applicability of RFEM and Eurocode 8 for pushover analysis were studied by analysing 2D and 3D structures obtained from the literature. A pushover analysis has some advances compared to simpler and much wider used linear response spectrum analysis. It gives valuable information about the location of first yield, overstrength ratio for behaviour factor revision and the actual plastic mechanism of the structure in an earthquake. However, the current guidelines in standards are not at a level that would allow the method to be applied easily and unambiguously in industrial design. It was found out that regular moment resisting frames are suitable for pushover analysis with RFEM and it can calculate the capacity curves and inspect the plastic hinge Eurocode 8 limit states. However, RFEM does not have the means to calculate the target displacement and is not suitable for pushover analysis of braced frames. If a structure is to be analysed with pushover analysis according to Eurocode 8, it should be ensured that the requirements for regularity in plan and in elevation are met.Tämän diplomityön tavoitteena oli lisätä tietämystä kehittyneestä seismisestä analyysimenetelmästä, pushover-analyysistä, sekä tutkia sen soveltuvuutta teräsrakenteiden seismiseen suunnitteluun. RFEM:n ja Eurokoodi 8:n soveltuvuutta pushover-analyysiin selvitettiin analysoimalla kirjallisuudesta löytyviä 2D- ja 3D-rakenteita. Pushover-analyysilla on joitakin etuja yksinkertaisempaan ja huomattavasti yleisemmin käytettyyn vastespektrianalyysiin verrattuna. Siitä saadaan arvokasta tietoa ensimmäisen myödön sijainnista, ylilujuuskertoimesta käyttäytymiskertoimen uudelleenarviointiin sekä rakenteen todellisesta plastisesta mekanismista maanjäristyksessä. Nykyiset standardien ohjeistukset eivät kuitenkaan ole riittäviä, jotta menetelmää voitaisiin soveltaa helposti ja yksiselitteisesti teollisessa suunnittelussa. Työssä saatiin selville, että säännölliset momenttikehät soveltuvat analysoitaviksi pushover-menetelmällä RFEM:ssä, ja että sillä voidaan laskea kapasiteettikäyrät ja tarkistaa plastisten nivelten Eurokoodi 8 -rajatilat. RFEM:ssä ei kuitenkaan voida laskea tavoitesiirtymiä, eikä se sovellu sidejäykistettyjen kehien pushover-analyysiin. Jos rakennetta analysoidaan pushover-analyysilla Eurokoodi 8:n mukaisesti, tulee varmistua, että säännöllisyysvaatimukset tason ja korkeuden suhteen täyttyvät

Combining Phi6 as a surrogate virus and computational large-eddy simulations to study airborne transmission of SARS-CoV-2 in a restaurant

COVID-19 has highlighted the need for indoor risk-reduction strategies. Our aim is to provide information about the virus dispersion and attempts to reduce the infection risk. Indoor transmission was studied simulating a dining situation in a restaurant. Aerosolized Phi6 viruses were detected with several methods. The aerosol dispersion was modeled by using the Large-Eddy Simulation (LES) technique. Three risk-reduction strategies were studied: (1) augmenting ventilation with air purifiers, (2) spatial partitioning with dividers, and (3) combination of 1 and 2. In all simulations infectious viruses were detected throughout the space proving the existence long-distance aerosol transmission indoors. Experimental cumulative virus numbers and LES dispersion results were qualitatively similar. The LES results were further utilized to derive the evolution of infection probability. Air purifiers augmenting the effective ventilation rate by 65% reduced the spatially averaged infection probability by 30%-32%. This relative reduction manifests with approximately 15 min lag as aerosol dispersion only gradually reaches the purifier units. Both viral findings and LES results confirm that spatial partitioning has a negligible effect on the mean infection-probability indoors, but may affect the local levels adversely. Exploitation of high-resolution LES jointly with microbiological measurements enables an informative interpretation of the experimental results and facilitates a more complete risk assessment.Peer reviewe

Omaisuudensuoja ja ympäristöperusoikeus rakennetun ympäristön suojelussa : Rakennussuojelun perustuslainmukaisuuden ennakkovalvonta

Perustuslain (731/1999) perusoikeudet omaisuudensuoja (PeL 15 §) ja ympäristöperusoikeus (PeL 20 §) ovat jännitteisessä tilassa rakennetun ympäristön suojelussa. Rakennetun ympäristön suojelu tarkoittaa sitä, että suojelutavoitteen kanssa ristiriitaiset omaisuuden käyttötavat kielletään. Rakennussuojelu voi merkittävästikin rajoittaa omistajan vapautta käyttää kiinteistöään lain muuten sallimalla tavalla. Lisäksi huomioon on otettava rakennusten suojelusta aiheutuva ylimääräinen kustannusrasitus. Päähuomio on vertikaalisuhteessa yksityisen ja julkisen vallan välillä. Keskeiset lait ovat maankäyttö- ja rakennuslaki (MRL 132/1999) sekä rakennusperinnön suojelemisesta annettu laki (RPSL 498/2010). Nämä lait muodostavat osin päällekkäisen suojelujärjestelmän, kun asemakaavaan voidaan ottaa MRL 57 §:n 3 momentin mukaisesti kohtuuttomiakin suojelumääräyksiä RPSL:n kautta. Tutkielmassa tarkastellaan rakennussuojelun vaikutuksia omaisuudensuojalle. Huomio keskittyy nimenomaan lainsäätämisvaiheessa tapahtuvaan perusoikeuksien, arvojen ja intressien väliseen punnintaan ja yhteensovittamiseen. Omaisuudensuojaa ja ympäristöperusoikeutta tarkastellaan erillisinä ja yhteensovitettuina perusoikeuksina. Eduskunnan perustuslakivaliokunnassa ratkaistaan lakien perustuslainmukaisuus eli se, edellyttääkö laki perustuslainsäätämisjärjestystä vai riittääkö tavallinen lainsäätämisjärjestys. Sekä MRL että RPSL säädettiin tavallisen lain säätämisjärjestyksessä, jolloin perustuslakivaliokunta ei katsonut niiden sisältävän omaisuudensuojaan kajoavia säännöksiä. Tutkielmassa yritän selvittää, että miksi näin kävi. Perustuslakivaliokunnan tulkintoja tarkastelemalla saadaan perustuslain arvovaltaisimmalta tulkitsijalta tietoa voimassa olevien perusoikeuksien sisällöstä. Tarkastelen tutkielmassa sitä, mihin kohtiin ja seikkoihin perustuslakivaliokunta kiinnitti huomiota lausunnoissaan MRL:sta ja RPSL:sta. Tätä kautta saadaan tietoa lakien kipukohdista suhteessa perusoikeuksiin. Perustuslakivaliokunnan mukaan rakennussuojelussa on kyse käytönrajoituksista, eikä se ole materiaalista pakkolunastusta. Kun rakennussuojelu on siten PeL 15 §:n 1 momentin soveltamisalaan kuuluvaa, niin täyttä korvausta korvauskynnyksen ylittämisen jälkeen voidaan sinällään pitää asianmukaisena. Olennaista olisi kuitenkin korvauskynnyksen toimivuus käytännössä. Kun kyse on pääasiassa vertikaalisuhteesta, niin perusoikeuksien yleiset rajoitusedellytykset ovat keskeisessä asemassa rajoituksen hyväksyttävyyden selvittämiseksi. Vaikka tietyt perusoikeuksien rajoitusedellytykset korostuivatkin perustuslakivaliokunnan lausunnoissa, niin keskeiseksi perusteeksi sille, että lakien ei katsottu loukkaavan omaisuudensuojaa oli mahdollisuus saada korvausta suojelun aiheuttamista haitoista (loukkauksen hyvittämisen periaate). Korvaussääntelyn toimivuus on keskeinen lakien legitimaation kannalta ja olennainen omaisuudensuojan täydentäjä. Loppuviimein omaisuutta turvaa pakkolunastuksen edellytykset. Omaisuudensuojan tulkintaympäristö on muuttunut perusoikeusuudistuksen jälkeen. Kulttuuriperinnön suojelemiseksi voidaan edellyttää omistajan sietävän tiettyjä rajoituksia omaisuutensa käyttöön, etenkin kun kulttuuriperintö on arvona on nostettu perusoikeustasolle. Omistajien on tunnistettava vastuunsa, ja samalla heidän omaisuutensa on turvattava asianmukaisin korvauksin. Kulttuurihistorialliset arvot tuovat mukanaan yleisen intressin tällaiseen omaisuuteen

The effect of hot-dip galvanizing on the fatigue resistance of structural steels

Tässä kandidaatintyössä tutkittiin kuumasinkitetyn teräksen väsymiseen vaikuttavia tekijöitä ja selityksiä väsymiskestävyyden heikkenemiselle. Tarkoituksena oli tuoda esille tietoa kuumasinkitetyn teräksen väsymisestä ja selvittää aihepiirin tutkimuksen nykytila jatkotutkimuksia varten. Kirjallisuuskatsaus kuumasinkitetyn teräksen väsymiseen liittyvistä standardeista ja tutkimuksista tehtiin alan kirjallisuutta sekä tietokantoja hyödyntäen. Katsauksessa saatiin selville kaksi merkittävintä teoriaa sinkkipinnoitteen murtumismekanismille sekä eriäviä tuloksia levyjen ja hitsausliitosten väsytyskokeista. Vallitsevan käsityksen mukaan kuumasinkityn teräslevyn väsymiskestävyys heikkenee high-cycle-alueella, ja heikentyminen johtuu pääasiassa pinnoitteen jäähtymisen tai väsytyksen aikana tapahtuvasta hauraiden faasien säröilystä. Säröilyn mekanismista ei ole saavutettu yksimielisyyttä, eikä hitsausliitosten väsymiskestävyydestä voida tehdä vielä johtopäätöksiä, kun otetaan huomioon tutkimusryhmien toisistaan poikkeavat tulokset.In this bachelor’s thesis, factors affecting fatigue in hot-dip galvanized steel and explanations for loss of fatigue resistance were investigated. The aim was to provide information on the fatigue of hot dip galvanized steel and to explore the present state of research in this area for further research purposes. A literature review of hot-dip galvanized steel standards and studies was conducted using literature and databases. Two major theories for the zinc coating fracture mechanism as well as different results from the fatigue tests of plates and welds were discovered. Hot-dip galvanized steel sheet is generally believed to have lower fatigue resistance in the high-cycle regime due to cracking of the brittle phases during cooling or fatigue. No consensus has yet been reached on the mechanism of cracking, nor can conclusions be drawn about the fatigue resistance of welded joints, taking into consideration the divergent results of different study groups

Designer-aligned Automated Interview Note-taking

Design research—referring in this thesis to the research activities carried out by designers as part of design projects—often involves the human-centered analysis of substantial volumes of qualitative data, presenting a promising application for emerging generative AI technologies. While AI-assisted qualitative research remains an extensively explored topic within the Human-Computer Interaction (HCI) discourse, the integration of AI into design research, differentiated by its intrinsic reliance on empathy and intuition, remains markedly uncharted. This thesis ventures into this underexplored domain through a mixed-methods research strategy, encompassing a formative study alongside the development and assessment of an AI-assisted note-taking prototype. The formative study reveals that design research relies heavily on the tacit knowledge of designers, underlining the importance of designer-AI alignment. Building on these insights and the broader discourse on human-AI trust, this work posits the development of intrinsic trust via designer-AI alignment as a central objective of AI-assisted design research and introduces the Integrity Gap framework as a catalyst for further investigation. Additionally, the evaluation of the note-taking prototype through a qualitative user study provides nuanced insights into designers' perceptions of AI-generated notes, situating the theoretical propositions of the formative study in a practical context

Argumentative review aggregation and dialogical explanations

The aggregation of online reviews is one of the dominant methods of quality control for users in various domains, from retail to entertainment. Consequently, explainable aggregation of reviews is increasingly sought-after. We introduce quantitative argumentation technology to this setting, towards automatically generating reasoned review aggregations equipped with dialogical explanations. To this end, we define a novel form of argumentative dialogical agent (ADA), using ontologies to harbour information from reviews into argumentation frameworks. These agents may then be evaluated with a quantitative argumentation semantics and used to mediate the generation of dialogical explanations for item recommendations based on the reviews. We show how to deploy ADAs in three different contexts in which argumentation frameworks are mined from text, guided by ontologies. First, for hotel recommendations, we use a human-authored ontology and exemplify the potential range of dialogical explanations afforded by ADAs. Second, for movie recommendations, we empirically evaluate an ADA based on a bespoke ontology (extracted semi-automatically, by natural language processing), by demonstrating that its quantitative evaluations, which are shown to satisfy desirable theoretical properties, are comparable with those on a well-known movie review aggregation website. Finally, for product recommendation in e-commerce, we use another bespoke ontology (extracted fully automatically, by natural language processing, from a website's reviews) to construct an ADA which is then empirically evaluated favourably against review aggregations from the website

Analysis of airport design for introducing infrastructure for autonomous drones

Funding Information: The entire research process has received external financial support from the Academy of Finland and is funded by the European Union – Next Generation EU. Publisher Copyright: © 2023, Harry Edelman, Joel Stenroos, Jorge Peña Queralta, David Hästbacka, Jani Oksanen, Tomi Westerlund and Juha Röning.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.Peer reviewe

Safe use of PHI6 IN the experimental studies

Surrogate viruses theoretically provide an opportunity to study the viral spread in an indoor environment, a highly needed understanding during the pandemic, in a safe manner to humans and the environment. However, the safety of surrogate viruses for humans as an aerosol at concentrations has not been established. In this study, Phi6 surrogate was aerosolized at concentration (Particulate matter(2.5): similar to 1018 mu g m(-3)) in the studied indoor space. Participants were closely followed for any symptoms. We measured the bacterial endotoxin concentration the virus solution used for aerosolization as well as the concentration in the room air containing the aerosolized viruses. In addition, we measured how the bacterial endotoxin concentration the sample was affected by different traditional virus purification procedures. Despite the puri-fication, bacterial endotoxin concentration of the Phi6 was high (350 EU/ml in solution used aerosols) with both (two) purification protocols. Bacterial endotoxins were also detected aerosolized form, but below the occupational exposure limit of 90 EU/m(3). Despite these concerns, no symptoms were observed in exposed humans when they were using personal protective equipment. In the future, purification protocols should be developed to reduce associated terial endotoxin levels in enveloped bacterial virus specimens to ensure even safer research use surrogate viruses.Peer reviewe

Analysis of airport design for introducing infrastructure for autonomous drones

Abstract 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 of drones. 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