Browsing by Title
Now showing items 3741-3760 of 4026
-
(2020)Within the last century humanity has grown significantly more numerous and more globally connected than ever before in its history. Together with the increased risks of climate change, we are more susceptible than ever to major epidemics and pandemics caused by novel zoonotic diseases. For these reasons it is not only important understand under which conditions novel pathogens are able to invade and spread in a host population but also to understand how these pathogens can be eradicated following an invasion event. In this thesis we present and study the demographic and evolutionary dynamics of a compartmental epidemiological model that includes a compartment for asymptomatic individuals, who require a second infection to become symptomatic and infectious. We show that the model exhibits a wide variety of demographic dynamical behaviour, all of which can be evolutionarily attracting configurations under simple evolutionary considerations. The model is an extreme simplification of the real world and excludes relevant information such as age and spatial structures of the population at hand. The aim of this thesis is to obtain a general understanding of how varying certain parameters on one hand allows a pathogen to invade a host population and, on the other hand, allows the host to eradicate an established pathogen, in particular, through the process of evolution.
-
(2020)This thesis provides information of the unjust geographies of girls and assesses empirical data on girls’ access to and through secondary education in Tanzania by using a case study approach. This study focuses on girls’ education in rural Mtwara because of its utmost importance. First, an internationally accepted human rights-based perceptive on girls’ education is present. Second, gender equality in and through secondary education has a direct and indirect effect on the reduction of overall poverty: employment and increased decision-making capabilities modify family opinions that further advance girls’ education and future asset accumulation that indirectly benefits the wider society. Rural Mtwara was chosen as a case study since it is characterized by particularly low secondary-school attendance and poor academic performance of girls. A number of variables affect access to education, including family and social factors as well as those related to the learning environment itself. Outside donors and governments can also affect the outcome. This study investigates the role of families in structuring the secondary school access of girls in low-income rural households, and it examines the individual, cultural, environmental, and economic factors that shape girls’ access to education in the rapidly changing environment of rural Mtwara. This study qualitatively explores how girls’ graduation from secondary school has benefitted both their lives and their families’ lives, especially in economic terms, and increased girls’ access to other spaces such as employment in a segregated society. Gender equal access remains a core issue of this study.
-
(2018)Tutkielman tavoitteena on esitellä ja konstruoida Stone–Čech kompaktisointi täysin säännöllisille avaruuksille. Tutkielmassa esitellään myös uniforminen avaruus ja käsitellään tämän yhteyttä pseudometriikoihin. Tutkielman alussa käydään läpi käytettäviä topologiaan ja joukkomerkintöihin liittyviä käsitteitä ja merkintätapoja. Lukijan oletetaan tuntevan yleisen topologisen avaruuden määritelmä ja tähän liittyviä perustuloksia. Peruskäsitteiden jälkeen esitellään uniforminen avaruus, eli topologinen avaruus, johon on lisätty uniforminen rakenne. Tämä rakenne mahdollistaa muun muassa täydellisyyden ja tasaisen jatkuvuuden määrittelyn ilman metriikkaa. Hausdorff uniformisoituvalle avaruudelle, eli täysin säännölliselle avaruudelle voidaan konstruoida Stone–Čech kompaktisointi. Tässä tutkielmassa Stone–Čech kompaktisointi konstruoidaan käyttäen upotusta yksikkövälien tuloon. Tulos voitaisiin konstruoida yhtäpitävästi myös muilla tavoilla, muun muassa ultrafilttereillä tai C*-algebroilla. Näitä muita tapoja emme kuitenkaan tässä työssä käsittele.
-
(2016)The subject of the thesis is related to the taste of housing in the Helsinki metropolitan area. The aim of this study is to analyze how a Finnish housing magazine describes housing and housing related taste in Helsinki Metropolitan area. Taste is investigated using Pierre Bourdieu's distinction theory, which aims to outline how home acts as a way of making distinction in forms of different kinds of capitals defined by Bourdieu. Bourdieu's theory's strength lies in its ability to combine inequality- and distinction related financial properties to their cultural equivalents. The research material consists of six decoration magazine Avotakka's volumes for years 1989, 1990, 1991.1999, 2000, 2001, 2009, 2010 and 2011. The data in the home presentation articles was analysed by using thematic distinction and image analyzis. The distribution of locations across the metropolitan area was also analysed and presented visually using appropriate maps. The analysis focused on background data related to residents such as age, occupation and way of living. In addition, the analysis addressed the location and location-related descriptions of the homes in question. Resident lifestyles and home characterizations were analyzed in particular on capital forms defined by Bourdieu. Based on the results it can be shown how Avotakka models and renews the values and ideals traditionally related to housing in Helsinki metropolitan area. The homes were located in districts already known for their prestige and value, thus further enforcing the already existing traits. The residents were mostly from the new middle class giving the right to define legit taste to a rather specific social group. Taste was highlighted by presenting residents' control of Bourdieu's capitals. Economic capital was disclosed by presenting the capability of acquiring residence from especially expensive areas in the city. Lifestyle-relate preferences, like eating out or taking city vacations, were also used to display capital. Especially the focus on expensive areas gave the impression of dream-homes being located in very specific areas. Thus acquiring a dream-home is left as a mere dream for the majority of people. The results however also revealed some inconsistencies in people striving to modes Finnish design but also aiming for distinction. The study focused on one magazine, Avotakka. To broaden the view additional studies should be conducted by including other magazines or by widening the readership research on readers' perceptions about housing.
-
Unimolecular Reaction Kinetics of Dimethyl-Substituted Stabilized Criegee Intermediate Acetone Oxide (2021)The Criegee intermediates (CIs) have been the topic for several studies and their role in global atmospheric chemistry is becoming better understood. Isoprene and monoterpenes form a large portion of the total biogenic volatile organic compound emissions in the forested regions of the world, isoprene being the most abundant non-methane hydrocarbon in the Earth's atmosphere. The carbon-carbon double bonds in these compounds are efficiently ozonized (the reaction where an unsaturated compound reacts with ozone) in the atmosphere leading to primary ozonides that subsequently decompose into Criegee intermediates and carbonyl compound molecules. Approximately 50 % of the CIs derived from acyclic alkenes immediately decompose in unimolecular reactions forming, e.g., hydroxyl radicals, the most important oxidizing species in the Earth’s atmosphere. The remainder is stabilized in atmospheric conditions in collisions with other molecules and are subsequently called stabilized Criegee intermediates (sCI). The sCI yields are often smaller, around 20 %, for Criegee intermediates formed in ozonolysis of cyclic alkenes, such as α-pinene. These sCIs can further react with atmospheric constituents (H2O, (H2O)2, SO2, NO2, organic acids etc.) in bimolecular reactions or decompose/isomerize in unimolecular reactions. The bimolecular reactions of sCIs with SO2 contribute significantly to the formation of atmospheric gas phase sulphuric acid and as such are an important factor in nucleation and formation of clouds. In the lower atmosphere, H2SO4 also has adverse health effects on humans and animals and causes corrosion of building materials. Additionally, unimolecular decay and bimolecular reactions of sCIs produce OH radicals. The experimental studies done so far have largely focused on the few simplest sCIs, i.e., formaldehyde oxide (H2COO), acetaldehyde oxide (CH3COO), and acetone oxide ((CH3)2COO). The studies on more complex sCIs, such as methyl vinyl ketone oxide and sCIs formed via ozonolysis of terpenes, are mostly done computationally. The literature review part of this work presents the basic mechanisms of formation and natural removal of sCIs as well as results of recent direct kinetic studies of sCIs with focus on the simplest ones (CH2OO, CH3CHOO, and (CH3)2COO). The methods of detection used in experimental studies are also considered. The experimental section concentrates on measurements of unimolecular decay kinetics of acetone oxide (CH3)2COO above and below room temperature using a new photolytic precursor (CH3)2CIBr. In the experimental section also the apparatus utilized in the research is presented along with the modifications and improvements made on the setup in this work. The calibrations done to ensure accurate measurements are also presented.
-
(2014)Tutkielmassa käsitellään 2D-pelien toteutuksissa käytettävistä pelimoottoreista Unity, XNA ja MonoGame. Tutkielman menetelminä ovat kirjallisuustutkimus sekä esimerkkisovellusten avulla tehty vertailu ja pohdinta. Tietokonepeleihin tutustutaan esittelemällä pelien tyylilajeja esimerkkipelien avulla. Pelimoottoreita ja niissä käytettäviä ohjelmointikieliä tarkastellaan yleisimpien ominaisuuksien osalta. Unity käsitellään omana lukunaan ja XNA sekä MonoGame käydään läpi omana lukunaan. Lopuksi esitellään Unityllä sekä MonoGamella toteutettu esimerkkipeli. Toteutusten sekä tutkielman teorian avulla pohditaan ja vertaillaan Unityn ja MonoGamen ratkaisuja 2D-pelien totetutuksessa. 2D-pelien tyypillisistä ominaisuuksista tarkempaan tarkasteluun valitaan peliikkunoiden välinen navigointi, pelilaudan kooostaminen sekä tekstuurien ja animaatioiden toteutus.
-
(2017)Genome-wide association studies have identified hundreds of genomic loci associated with a wide range of human conditions and quantitative traits, such as cholesterol level and diabetes. However, most of these studies have focused on analysing single traits, even the studies involving multiple related traits. Growing evidence for pleiotropy, where the same genetic locus is associated with multiple traits, supports the idea that multivariate methods could provide a remarkable boost in statistical power compared to univariate methods. In this thesis the main research question is to compare the multivariate Wald test to the corresponding univariate test, and to see when multivariate testing is more useful. My second research question is to compare the multivariate Wald test and another multivariate method called Canonical Correlation Analysis (CCA), and to see if they yield the same result. To examine these topics I performed a simulation study in which I simulated data set with 1,000 genotypes and 1,000 individuals. In addition I simulated bivariate phenotypes that were differently correlated with each other, and the genotypes. I performed the univariate Wald test for each trait against each genotype, and the multivariate Wald test for each trait pair against each genotype. I also performed the corresponding CCA to compare those results with the Wald test. In addition to the simulation study I performed the similar analyses for real data from The National FINRISK Study. I used three different blood lipid measurements, HDL-cholesterol, LDL-cholesterol and triglycerides as example traits, and 157 genomic loci previously known to associate with blood lipid levels. These blood lipid levels were appropriate example traits for this study because they are correlated differently with each other, and they are differently associated with the 157 genomic loci used here. Therefore I found many different combinations of correlation between traits, and directions of genetic effects for different traits. Based on my simulation studies I can say that the multivariate testing is never much worse in terms of power to detect associations than the corresponding univariate tests, and in some cases it is much more powerful. Thus there is no reason not to do the multivariate analysis first in case of studying multiple related traits. Multivariate testing is more powerful in cases where the correlation between the traits is large and the genetic effects for the traits show opposite directions compared to the trait correlation. The least effective multivariate testing is compared to univariate testing when the correlation between the traits is small, and the directions of genetic effects is consistent with the trait correlation. Based on my results multivariate Wald test and CCA yield the same results, with some minor approximation differencies in small sample sizes.
-
(2013)The purpose of this thesis is to study the asymmetric simple exclusion process, its asymptotics and some connections to other stochastic models. The text begins by giving some results on random matrix theory, such as the distribution function of the largest eigenvalue of a given random matrix. This is followed by a short section on the totally asymmetric simple exclusion process, which is a stochastic model of fermionic particles jumping only in one direction on a one-dimensional lattice. The probability that a given particle has jumped m times is then shown to be equal to the distribution of the largest eigenvalue of a specific type of a random matrix analyzed earlier. As this hints at some kind of universality, the particle model is then generalized to the asymmetric simple exclusion process, in which the particles can jump left or right. It turns out this model does not have the simple determinantal structure the earlier models had. The asymptotics of the model will then be analyzed, and it turns out there is a large universality class that encompasses all the models analyzed in the text. The reader is expected to be familiar with basic measure theory and complex analysis.
-
(2018)I arbetet undersöker vi ett nytt och relativt outforskat område inom den matematiska analysen kallat universalitet. Idén är att utgående från ett enda element och med hjälp av någon divergerande eller "kaotisk" process approximera en hel klass med element. Mer formellt kan processen ses som en familj av kontinuerliga avbildningar från ett rum X till ett rum Y. Om det existerar ett sådant element i X att familjen avbildar detta till en tät mängd i Y kallas detta element för ett universellt element och familjen för en universell familj. I arbetet definierar och undersöker vi universalitetens egenskaper, olika exempel på universalitet, samt en förenklad version av universalitet kallad hypercyklicitet och det till universalitet nära förknippade fenomenet topologisk transitivitet. Till slut visar vi även hur teorin via den topologiska transitiviteten även är kopplad till de dynamiska systemens kaosteori.
-
(2014)Unkarin koulujärjestelmä ei eroa paljon Suomen järjestelmästä. Oppivelvollisuus kestää 18-vuotiaaksi ja julkinen valtion ylläpitämä koulutus on maksutonta. Lisäksi on yksityisiä kouluja. Kömal on vuonna 1984 perustettu unkarilainen matematiikkalehti, joka järjestää kuukausittain matematiikkakilpailuja unkarilaisille koululaisille. Kilpailutehtävistä löytyy Kömalin verkkosivulta englanninkieliset käännökset, ja ne ovat kaikkien saatavilla. Suomessa matematiikkakilpailut eivät ole yhtä suosittuja kuin Unkarissa, mutta tarjolla on sekä kansallisia että kansainvälisiä kilpailuja. Tähän työhön olen suomentanut 116 kilpailutehtävää eri vuosilta. Kaikki tehtävät ovat kilpailun helpoimmasta kategoriasta. Ainakin tässä kategoriassa oli eniten geometrian tehtäviä. Tehtävien luokittelu eri aihealueisiin ei kuitenkaan ollut aina helppoa, sillä lähes kaikkien tehtävien ratkaisemiseen tarvitaan osaamista useilta matematiikan osa-alueilta. Analysoimieni tehtävien perusteella unkarilaiset matematiikan tehtävät ovat haastavampia ja moniulotteisempia kuin suomalaiset tehtävät. Suomessa matematiikka pilkotaan osa-alueisiin, joiden välinen yhteys saattaa jäädä epäselväksi. Unkarilaisen mallin mukaan matematiikka on yksi iso kokonaisuus, jossa kaikki palaset liittyvät toisiinsa. Analysoimani tehtävät olivat kilpailutehtäviä, eivätkä siis välttämättä vastaa unkarilaisten oppikirjojen tehtäviä. Kaikki analysoimani tehtävät ovat kilpailun helpoimmasta kategoriasta, jossa nuorin kilpailijaryhmä luokille 1-8 eli 6-14-vuotiaille oppilaille. Näistä suurin osa tehtävistä on mielestäni liian haastavia suomalaisille peruskoululaisille, tietysti kilpailuun osallistuminen ylipäätään edellyttää matemaattista harrastuneisuutta.
-
(2016)This thesis is an investigation of unsupervised learning for image classification. The state-of-the-art image classification method is Convolutional Neural Network (CNN), which is a purely supervised learning method. We argue that despite of the triumph of supervised learning, unsupervised learning is still important and compatible with supervised learning. For example, in the situation where some classes have no training data at all, so called zero-shot learning task, unsupervised learning can leverage supervised learning to classify the images of unseen classes. We proposed a new zero-shot learning method based on CNN and several unsupervised learning algorithms. Our method achieves the state-of-the-art results on the largest public available labelled image dataset, ImageNet fall2011.
-
(2023)The objective of this thesis was to explore the article corpus of a domain-specific Finnish-language newspaper to generate a new content tag word set to replace an existing one of poor quality. The articles used as the dataset in this study had previously human-assigned content tags, but in absence of a proper tagging strategy and guidelines, the assigned tags were found to include too much variation to be useful, e.g., as search terms. No supervised learning models were used, since there was no good quality training material available specific to the topics of the data. Instead, we experimented in generating new tagsets with two unsupervised methods alongside a few variations based on nouns and proper nouns in the text content of the articles. A proper tag set would be useful in tagging future articles automatically or in drafting guidelines for manual tagging of future articles by the journalists. A limited survey among subject matter experts and other responders was conducted in order to evaluate the results generated by the methods. In general, the results were not encouraging, with the most basic model TF-IDF clearly performing better than the other models across all responders. Further examination after topic modeling using Latent Dirichlet Allocation (LDA) revealed, that somewhat better scores could be found among some topics. A further manual task of assessing and naming of the topics followed by a new tagging effort within topics was suggested as a next step in order to overcome the deficiencies in the presented methods.
-
(2022)In this thesis, a novel method for linking scientific articles to taxonomy terms in the domain of food systems research is presented. With food systems being in the center of 12 of the 17 United Nations Sustainable Development goals, there has been an ever-growing amount of scientific articles in this field. These articles are vital in understanding the complex nature of food systems and their inter-dependencies. However, finding relevant literature in this field is difficult for decision makers given the interdisciplinary nature of the field and that annotation and expert feedback is expensive. In the thesis, BERT-based models (SBERT, SPECTER and SciBERT) are adapted to the food systems area and fine-tuned for tasks such as text classification and text similarity, which represents a solution to the problem of finding relevant articles in the food systems domain. The proposed search system uses several taxonomies and data augmentation to achieve the results, which are visualized in a created website. Linking food systems research articles to taxonomy terms shows good accuracy, with models finetuned on domain data achieving better performance on classification task. The best fine-tuning strategy for SPECTER and SciBERT is the combination of domain adaptation and classification. Fine-tuning for text similarity for SBERT improves SBERT performance only slightly. The proposed method can be used in other domains than food systems.
-
(2014)In situ U–Pb zircon dating was done for the host rocks of the Juomasuo gold deposit, located in the Paleoproterozoic Kuusamo supracrustal belt, eastern Finland. For dating purposes, five samples were chosen to represent the typical volcano-sedimentary rock types of the deposit in their mineralized and unmineralized form. The samples were studied petrologically and dated using the LA–MC–ICP/MS technique at the research laboratory of the Geological Survey of Finland and the Finland Geoscience Laboratory (SGL). The U–Pb data revealed heterogenic detrital zircon populations even for the felsic volcanic rocks, and thus, all the samples were delineated as sedimentary/volcano-sedimentary sequences. The maximum deposition ages fall in the 2.75–2.65 Ga window, and not a single Paleoproterozoic age was measured in the bulk of 159 measurements. The pervasively altered samples from the mineralized sequence of the Juomasuo deposit hosted a younger population of homogenized, BSE-pale/CL-dark zircons and domains within zircon grains, with 2.62–2.60 Ga ages. This age can be linked to the Neoarchean crustal growth event at 2.7–2.6 Ga, described from the Archean terrains all over the world, including the Archean of the Karelia Province in Finland. Unfortunately, in the limits of this thesis, the homogenization age cannot be interpreted as the minimum depositional age of the studied metasedimentary rocks, as it remains unclear, whether the homogenization of the zircons took place before or after the deposition. Although the majority of the precursors of the studied supracrustal rocks from Kuusamo were presumably deposited between 2.43 and 2.21 Ga, there are no corresponding ages of volcanism in the area. The lack of U–Pb ages of that time frame is a global phenomenon, and the topic is thus pertinent to modelling of Paleoproterozoic plate tectonics. It may be that the Kuusamo supracrustal belt represents a deposition during a global slowdown in plate tectonics, thus recording an anomalous period in the history of planet Earth.
-
(2014)Tutkimuksessa pohdittiin kellumiseen ja uppoamiseen liittyvien ennakkokäsitysten hyödyntämisen mahdollisuuksia nosteen opetuksessa. Oppimisen tavoitteiden kannalta validien ennakkokäsitysten lisäksi pohditaan myös virhekäsitysten hyödyntämistä. Tässä tutkimuksessa tutkittaville 50 oppilaalle suoritettiin ennakkokäsitystesti, jonka jälkeen haastateltiin yhdeksää oppilasta. Haastattelut olivat kahden keskisiä opetustilanteita, joissa keskustelu aloitettiin oppilaan lomakevastauksien ja vastausten perusteluiden pohtimisesta. Keskustelua vietiin eteenpäin kysymysten ja havainnollistavien esimerkkien avulla. Oppilaan käsityksiä nosteesta pyrittiin siis kehittämään oppilaan lähtökohdat huomioon ottaen. Tämän tutkimuksen perusteella yläkouluikäiset voidaan luokitella karkeasti kolmeen ryhmään ennen nosteen opetusta. Haastavimmat oppilaat selittävät nostetta fysikaalisen painon avulla; painava kappaleet uppoavat ja kevyet kelluvat. Tässä ryhmässä noste saatettiin jopa nähdä väliaineen vastuksen kaltaisena vastusvoimana, jolloin esim. väliaineen viskositeetti tai väliaineeseen asetetun kappaleen terävyys vaikuttaa kellumiseen. Keskimmäinen ja suurin ryhmä ovat oppilaat, jotka selittivät nostetta ominaispainon avulla. Selityksellä pärjää jo monissa tilanteissa, mutta siitä puuttuvat käsitteet massa, tilavuus ja tiheys sekä paino ja noste fysikaalisina voimina. Osa keskimmäisen ryhmän oppilaista omaa selityksen nosteen aiheuttajalle; maa vetää väliainetta joko kovempaa tai hiljempaa kuin väliaineessa olevaa kappaletta. Opetuksen kannalta vaivattomin ryhmä ovat oppilaat, jotka käyttivät päättelyissään fysikaalisia suureita kuten massa, tilavuus ja tiheys. Nämä oppilaat ymmärsivät myös, että noste syntyy paineesta, mutta paine-eron käsite ei ollut heilläkään käytössä. Virhekäsitystestin perusteella tavallisin virhekäsitys oppilailla oli kappaleen pinta-alan yhdistäminen nosteen suuruuteen; kappale kelluu helpommin mikäli paino on jakautunut suuremmalle alalle. Nesteellä on siis jonkinlainen kelluttavat ominaisuus, joka on levittäytynyt sen pinnalle. Kyseinen virhekäsitys ei ole täysin huono, sillä noste on paineesta syntyvä voima ja paineesta syntyvät voimat riippuvat usein pinta-alasta. Virhekäsitys häviää, jos oppilas oppii ymmärtämään nosteen syntymekanismia paremmin. Pinta-alan ja paine-eron välisen yhteyden oppiminen vaatii ymmärrystä siitä, että noste syntyy kappaleen ylä- ja alapuolen välisestä paine-erosta. Kun kappaleen pinta-ala kasvaa, paine-ero pienenee. Kolme haastateltua oppilasta olivat valmiita vastaanottamaan edellä mainitun päättelyn heidän omista lähtökohdistaan. Ennakkokäsitystesti synnytti tai toi esiin myös paljon muita virhekäsityksiä. Tämä johtui osittain siitä, että testin kysymyksissä esiintyi tarkoituksella ominaisuuksia, jotka intuitio saattaa yhdistää uppoamiseen ja kellumiseen. Oppilaat tukivat perusteluitaan näillä konkreettisilla ominaisuuksilla huolimatta siitä, että jokaisesta kysymyksestä pystyi päättelemään minkälainen kysytyn kappaleen tiheys on. Tiheyden sijaan perustelut oli helpompi muotoilla mm. kappaleen painon, kaasupitoisuuden, reikäisyyden, litteyden, terävyyden, asennon, kovuuden, täytemateriaalin, väliaineen määrän ja väliaineen viskositeetin perusteella. Tämän työn tulokset osoittavat että on vaikea tunnistaa, missä vaiheessa ja miten ennakkokäsitykset syntyvät. Perinteisesti on ajateltu että ennakkokäsitykset syntyvät opetusta edeltävistä havainnoista ja sosiaalisesta vuorovaikutuksesta. Osa ennakkokäsityksistä saattaa kuitenkin syntyä vasta opetustilanteessa. Virhekäsityksiä ei tarvitse kauhistella, sillä ne saattavat olla oppilaan ensimmäisiä yrityksiä ratkaista jokin fysikaalinen ongelma tieteellisessä kontekstissa.
-
(2018)The trending of urban living during recent years can be seen both in public debate and in growth statistics of cities. The most attractive areas in addition to regions’ central cities are those surrounding municipalities which have good transportation connections to the central city and have managed to highlight their urban features. The trend can clearly be seen in the city of Järvenpää, which was, with annual population growth of 2,5 %, the fastest growing municipality in continental Finland in 2016–2017. As the popularity of urban living is growing, the focus of construction in Järvenpää has shifted from traditional single-family and low-rise housing to apartment buildings located close to train stations. This Master’s thesis looks at the pull factors of the new urban residential areas in Järvenpää as well as factors encouraging to settle down in the areas. The reasons for moving to the areas are compared to current social, demographic and migration trends. The study addresses the residents' point of view to housing phenomena. The aim is to pay attention to the connections between household decision-making processes and broader migration phenomena. In addition, the aim is to supplement the field of housing and migration studies in Finland, in which the focus has been in the dynamics between the urban areas of the regional centers and the suburbs of the surrounding municipalities, while less attention has been payed to the differing characteristics of the surrounding areas. The research problem is approached through the following questions: who are the residents of the new residential areas located near train stations in Järvenpää; which factors most significantly guide the housing choices of these residents; and how do the residents’ housing pathways form regionally and structurally. The analysis and discussion are supported by the contextual framework of housing chains, developed in the theory section of the thesis. The data was collected through a survey in spring 2018. The survey was targeted to certain new areas close to the train stations of Järvenpää and Ainola. The survey was sent to altogether 1548 residents. 400 replies were received, which makes the response rate 26 %. Based on an analysis of possible non-response bias, the data was observed to be relatively representative to the population, apart from the elderly being somewhat overrepresented. The main analysis methods where statistical analyses (frequency analysis, cross tabulation and factor analysis) as well as content analysis of the open-ended questions. The data was mainly analyzed through comparisons of different kinds of residential areas as well as demographic groups. The results of the study can be summarized in three main points. Firstly, the new residential areas located near train stations in Järvenpää reflect broader social and demographic trends as well as current trends in housing . In the areas close to the city, majority of the residents live alone and are young adults or elderly. Similar to national trends, the housing preferences included single-family housing and peaceful living environment, but at the same time, services, central location and good transportation were valued. Secondly, the attractiveness of the area in all study areas was based on central location and good transportation and in the fact that the apartments were new. However, there were differences in the importance of services and nature when comparing the apartment building areas closest to the center and the apartment building areas and detached house areas farther from the center. Thirdly, it was observed that the areas not only bring new residents to the city, but also pull a notable amount of people to move within the city. The new areas thus connect to the existing housing stock and start vacancy chains by opening vacancies in both detached houses and older apartment buildings. Various housing chains also occurred in how the social contacts outside households, the stage of family life-cycle, previous experiences and values affect housing choices. Based on the results, it can be noted that successful urban apartment building housing in the surrounding municipalities is characterized by good commercial and public services and efficient transportation, whereas in detached housing, the desired environment is centrally and transportation-wise well located but peaceful and close to nature. The significance of the services and transportation in housing satisfaction should be acknowledged early on when planning and building new areas . Also, lifestyles and situations change, and that affects housing choices. The results indicate that diverse housing options will have demand alongside the high-rise building boom. Additionally, it is important to acknowledge the interrelations between new construction and the existing housing stock to avoid making simplified interpretations about the logic of growth sustained by the trend of urban living.
-
(2020)The themes of this thesis are alternative, informal, and uncommercial cultural spaces, the scenes using the spaces, and the individual scene participants. The study’s frame is Helsinki between 2000–2019. The study combines relevant theoretical discussion from subculture research tradition and urbanism. The key concepts of the thesis are ‘scenes,’ a cultural definition of ‘subculture,’ ‘alternative cultural spaces,’ ‘DIY culture’ (‘do it yourself’), and ‘enclaves.’ The thesis presents Helsinki’s ‘DIY landscape’ to consist of interconnected actors—scene participants—who are part of a network that revolves around making, performing and facilitating music in a specific urban infrastructure—the city, Helsinki—and in which the alternative cultural spaces create physical ‘hubs’ for the scene. The data has been collected online via a combination of oral history recollections and qualitative surveying. The data was collected in collaboration between Helsinki City Museum and Music Archive Finland in fall 2019. The data consist of 70 individual responses. The data is treated through the epistemology of qualitative research and oral history, and therefore is seen to include both ‘factual’ information and the informant’s subjective interpretations, their experience. On a practical level, the analysis has been conducted mainly via qualitative content analysis (QCA), but also geographic information system (GIS) has been used. The study aims to explicate a widely recognized but poorly known cultural phenomenon. The study’s key results are as follows. Four types of alternative cultural spaces have existed: dedicated buildings, rooms, outdoor venues, and even a ship. All of the study’s 34 spaces have hosted live music events and a variety of other cultural, political, and social activities. The spaces have been acquired for use by renting, squatting, and asking permission, and in two cases are owned by the facilitator. With some exceptions, they are located in the fringe areas of Helsinki’s city center, have a relatively short lifespan (maximum of five years in a set location) and share ‘aesthetics of necessity’ that roots meager or non-existent funding and the use of subcultural symbols and art. The spaces follow certain ‘DIY operating principles’ that aim to create an encouraging and inclusive atmosphere for DIY participation. The spaces, and their users, have faced a variety of challenges, setbacks, and problems. These are rooted in funding, the deficits of the buildings and their facilities, and to other citizens, the police, and the City of Helsinki. The City’s role emerges from the data as ambivalent—a constrainer and enabler. According to the responder’s experience, the City does not have a uniform policy towards the use of vacant urban space, and DIY culture overall is not recognized. For the scenes, the alternative cultural spaces function as platforms where cherish—often ‘marginal’—music and subcultures. Some of the participants connect political and societal ideals to the spaces and DIY activities. DIY activities emerged as—sometimes self-purposefully—social and communal by their nature. In the spaces between scene participants take place socio-cultural ‘cross-fertilization,’ which sometimes leads to new organizational groups and even scenes forming. These might relocate their practices elsewhere, and thus DIY culture spreads to new locations in the urban infrastructure. For the individual scene participants, crossing with the scene represents an important part of finding a social reference group. Some of the responders described going through a ‘DIY phase,’ which is a several yearlong period in their youth when life orientations and identity are intensively connected to DIY culture. The meaningfulness of scene participation lasts to later life, even if the participant’s active years are foregone. For some, the skills and knowledge acquired in the scene creates a basis for a more professional career in cultural production. As the reasons for the diminish or end of the DIY participation are given the closure of an alternative cultural space focal for the participant, challenges in activities, and major life events. In the discussion, the thesis suggests the concept of ‘urban DIY enclaves’ in the toolboxes of urban planners and designers. The DIY enclaves differentiate from the broader urban landscape by their condition, aesthetics, political messages, and subcultural symbols. Socially they have been constructed to advance DIY culture and cherish the creative lifestyle associated with it. The concept is suggested as a device for acknowledging the existence of DIY culture; in other words, its need for space, and its participants’ eagerness to participate in the construction of the urban and cultural landscape.
-
(Helsingin yliopistoHelsingfors universitetUniversity of Helsinki, 2009)Inadvertent climate modification has led to an increase in urban temperatures compared to the surrounding rural area. The main reason for the temperature rise is the altered energy portioning of input net radiation to heat storage and sensible and latent heat fluxes in addition to the anthropogenic heat flux. The heat storage flux and anthropogenic heat flux have not yet been determined for Helsinki and they are not directly measurable. To the contrary, turbulent fluxes of sensible and latent heat in addition to net radiation can be measured, and the anthropogenic heat flux together with the heat storage flux can be solved as a residual. As a result, all inaccuracies in the determination of the energy balance components propagate to the residual term and special attention must be paid to the accurate determination of the components. One cause of error in the turbulent fluxes is the fluctuation attenuation at high frequencies which can be accounted for by high frequency spectral corrections. The aim of this study is twofold: to assess the relevance of high frequency corrections to water vapor fluxes and to assess the temporal variation of the energy fluxes. Turbulent fluxes of sensible and latent heat have been measured at SMEAR III station, Helsinki, since December 2005 using the eddy covariance technique. In addition, net radiation measurements have been ongoing since July 2007. The used calculation methods in this study consist of widely accepted eddy covariance data post processing methods in addition to Fourier and wavelet analysis. The high frequency spectral correction using the traditional transfer function method is highly dependent on relative humidity and has an 11% effect on the latent heat flux. This method is based on an assumption of spectral similarity which is shown not to be valid. A new correction method using wavelet analysis is thus initialized and it seems to account for the high frequency variation deficit. Anyhow, the resulting wavelet correction remains minimal in contrast to the traditional transfer function correction. The energy fluxes exhibit a behavior characteristic for urban environments: the energy input is channeled to sensible heat as latent heat flux is restricted by water availability. The monthly mean residual of the energy balance ranges from 30 Wm-2 in summer to -35 Wm-2 in winter meaning a heat storage to the ground during summer. Furthermore, the anthropogenic heat flux is approximated to be 50 Wm-2 during winter when residential heating is important.
-
(2022)As biodiversity loss is identified to be one of the pressing environmental challenges today, Finnish cities have begun to follow in the footsteps of many European cities by creating urban greening plans in the form of increasing meadow habitats. The ecological and economic benefits of urban meadows are well understood, but when meadow habitats are brought into people’s everyday environments, it is important to consider how it affects people’s environmental aesthetic experiences. ‘Aesthetics’ is often understood solely as individual preferences, but the aim of this thesis was to address the aesthetic appreciation of meadows through the field of environmental aesthetics. Combining the fields of environmental aesthetics and ecology, this study provides a fresh perspective to the value debate over urban meadows. The analysis of the work approached the topic from the perspective of Finnish cities. After compiling the operational programs that solely consider urban meadows, qualitative content analysis was used to analyze what ecological and aesthetic aspects are brought up in the documents and how they are valuated. To emphasize the aesthetic perspective, it was further investigated through discourse analysis whether there are consistent ways in which cities construct an image of the aesthetic values of urban meadows. The content analysis showed that the documents have both ecological and aesthetic viewpoints. The ecological content emphasized that meadows are important tool in increasing biodiversity and also provide recreational possibilities for people. The aesthetic content focused on the cultural-historical role of the meadows as well as the experiences provided by the meadows. Based on the content analysis, three uniform discourses were identified throughout the documents. The first relates to meadows which are the remains of cities’ agricultural history, and their cultural and ecological values are easily recognizable. The second refers to meadows that are currently emerging from other green types such as lawns and grasslands reverting to woodland. They are seen as having ecological and recreational value, but as they are unlikely to meet the expectations for flowering meadows, city officials want to inform citizens about the ecological qualities of these meadows to avoid negative feedback. The last discourse focuses on the experiential side of meadows, but instead of talking about the environmental aesthetic experience as understood in theoretical research, the argumentation is restricted to visual and recreational experiences. The way in which the aesthetic qualities, values and experiences of urban meadows are understood in a professional context reflects the way in which they are presented to the users of green areas. This thesis has revealed that the terminology used in the documents referring to environmental aesthetics is insufficient and does not correspond to the concepts presented in the theory of the work. Expanding the debate on environmental aesthetics would turn the goal of ‘people tolerating unordered ecosystems’ to ‘how can unordered ecosystems be aesthetically appreciated’. While informing citizens about the ecological benefits of urban meadows, they should also be informed about the potential aesthetic values of urban meadows, such as wildness, aesthetic diversity, and how the ordinary environment becomes extraordinary.
-
(2014)Lagos is the biggest city not just in Nigeria but also in the Sub-Saharan Africa. This megacity has a reputation of being the most dangerous and chaotic city in the world. Despite that Lagos is facing an infrastructural crisis and most of the city acts through informal means, it has its own way to survive and operate. The purpose of this study is to create a picture of the urban structure of Lagos Metropolitan Area and compare it with the existing urban structure models. The purpose is also to discover the possible affects of existing zoning plans on the current structure and dynamism of the city. Again, the aim of this research is to study the characteristics of the metropolis and reflect them to the postmodern concepts of Myers's that intend to explain the nature of modern African cities. This study tries to provide new perspectives on the image of the study area. However, this study tries not to draw a detailed picture of every district of the metropolis but aims at highlighting the dominant features of the city. This study adopts qualitative research methods and is descriptive by its nature. The primary data consists of researches, maps, scientific articles, project documents and different kinds of publications concerning the for example landuse and dominant features of different districts and neighborhoods of Lagos. The data collected from these sources is combined and analyzed in order to create a visualization over the urban structure of Lagos. The secondary data was collected during the field trip in Lagos in 2009 and consists of observation notes. It serves as a supportive tool in the descriptive part of the work. The study concludes that the city structure in Lagos consists much of poor residential districts and slum areas. Most of the citizen live in poverty as medium- or high-grade districts do not exist nearly at all. Lagos is often described as industrial centre of Nigeria, but in reality the industrial activity is not particularly high since the weak infrastructure and low security situation of the city does not attract investors. Again, the structural analysis discovers that the city has currently just one clear core area. The large area of the metropolis would demand several central business districts to improve the mobility and selection of public services of the city. This study suggests that Lagos can be very easily described and expressed with the concepts presented by Myers. On the grounds of his concepts, Lagos has several features typical of modern African city. Colonial era has left its fingerprints both on the city structure and dynamics. The informal sector has a remarkable role in Lagos and violence is a constant part of the streets. Despite that, Lagos has slowly found its place among the global urban centres. Its significance as a centre of trade and culture keeps growing in the future. On the basis if this research it can be argued that there is a great need for urban structure studies in Africa. Often areas that appear as disorganized shantytowns include some structures and operating models of their own. By creating updated structure models and studies it is possible to affect positively on urban planning trends and also local development.
Now showing items 3741-3760 of 4026