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(2019)Rakennustoiminta on yksi kaupunkialueiden veden laatua heikentävistä tekijöistä. Rakentamisen aikaiset vesistövaikutukset voivat olla suuria ja niitä on tärkeää tunnistaa, jotta kaupunkipurojen veden laatua ja ekosysteemejä voitaisiin suojella. Tutkimuksen tavoitteena oli selvittää, millaisia vaikutuksia valuma-alueella tapahtuvalla rakennustoiminnalla on kaupunkipuron veden laatuun verrattuna rakentamista edeltävään aikaan. Lisäksi tavoitteena oli arvioida puron nykyistä veden laatua ja sitä, onko Kuninkaantammen hulevesipilottialueen vesiensuojelutoimenpiteillä ollut vaikutusta veden laatuun. Hypoteesinä oli, että rakentaminen on heikentänyt veden laatua lisäämällä merkittävästi kiintoaine- ja ravinnekuormitusta sekä metallipitoisuuksia ja että rakentamisen aikaisen hulevesisuojelun toimenpiteet eivät ole olleet riittäviä. Tutkimuskohteena oli Luoteis-Helsingissä sijaitseva kaupunkipuro Hakuninmaanoja, joka sijaitsee valuma-alueella, jolla on käynnissä Kuninkaantammen kaupunginosan rakennustyöt. Rakentaminen alkoi vuonna 2013 ja hankkeen arvioidaan valmistuvan vuonna 2025. Veden laatua tutkittiin kesän 2018 aikana aikavälillä 1.6.–11.9.2018, minkä lisäksi tutkimuksessa hyödynnettiin laajaa, 4.7.2011 lähtien kerättyä Hakuninmaanojan veden laadun aineistoa. Tutkittuja muuttujia (21 kpl) olivat kiintoaine ja orgaaninen aines, ravinteista kokonaistyppi ja kokonaisfosfori, liuenneen aineen kokonaispitoisuus, liuenneista kationeista natrium, kalium, kalsium ja magnesium, liuenneista anioneista fluoridi, kloridi, nitraatti ja sulfaatti, ja metalleista alumiini, mangaani, rauta, nikkeli, kupari, sinkki, kadmium ja lyijy. Tutkimuksessa tarkasteltiin muuttujien pitoisuuksien muutoksia havaintojakson aikana sekä verrattiin vuoden 2011 havaintoja vuoden 2018 havaintoihin. Muutoksen tilastollista merkitsevyyttä arvioitiin wilcoxonin merkittyjen sijalukujen testillä ja muuttujien välisiä korrelaatioita spearmanin järjestyskorrelaatiokertoimella. Kokonaistyppi- ja nitraattipitoisuudet kohosivat voimakkaasti esirakennustöiden aikana tehtyjen kallioräjäytystöiden myötä. Kokonaistyppipitoisuus oli kolmin- ja nitraattipitoisuus lähes viisinkertainen verrattuna rakentamista edeltävään aikaan. Kiintoaine- ja kokonaisfosforipitoisuudet laskivat rakentamista edeltäviin pitoisuuksiin nähden kolmas- ja neljäsosaan ja pysyivät korttelirakentamisen aikana verrattain matalina. Metallipitoisuudet laskivat tai pysyivät ennallaan tutkimusjakson aikana lukuun ottamatta sinkkipitoisuutta, joka kohosi korttelirakentamisen aikana. Metallipitoisuudet olivat kaiken kaikkiaan verrattain matalat ja useimpien metallien pitoisuusvaihtelun ei voitu arvioida olleen yhteydessä rakentamiseen. Kalium- ja fluoridipitoisuudet kohosivat typen lailla runsaimman maanmuokkauksen aikana eroosiosta ja räjäytystöistä johtuen. Rakennustöillä ei ole juuri ollut vaikutusta tutkittujen liuenneiden anionien ja kationien pitoisuuksiin. Hakuninmaanojan veden laatu on rakennustoiminnasta huolimatta useimpien muuttujien osalta tyydyttävä tai hyvä. Kuninkaantammen hulevesipilottialueen hulevettä puhdistavien ratkaisujen myötä ainakin kiintoaine- ja fosforipitoisuuden huippuarvot ovat pysyneet matalalla tasolla verrattuna aiempiin rakennustoiminnan vaikutuksia selvittäneisiin tutkimuksiin.
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(Helsingin yliopistoHelsingfors universitetUniversity of Helsinki, 2008)Sanakirjat ovat rakenteisia tekstejä. Sana-artikkeleissa on nähtävissä selvästi erotettavissa olevia rakenneosia. Painetun sanakirjan muuntaminen rakenteiseen muotoon ei kuitenkaan ole aivan suoraviivaista. Tässä tutkielmassa kerrotaan sanakirjan rakennekuvauksen määrittelyn ja painetun sanakirjan rakenteistuksen ongelmista. Esimerkkinä käytetään Kotimaisten kielten tutkimuskeskuksessa (Kotus) kirjoitettavan Suomen murteiden sanakirjan (SMS) rakenteistusprojektia ja sen yhteydessä määriteltyä rakennekuvausta. SMS:n rakennekuvausta verrataan kielitieteellisten aineistojen koodaamisessa yleisesti käytetyn Text Encoding Initiative -suosituksen sekä uuden ISO 1951:2007 -sanakirjastandardin määrittelemiin rakennekuvauksiin. Muuntamista testataan käytännössä kirjoittamalla XSL-muunnosskripti, joka muuntaa SMS:n aineiston ISOstandardimuotoon. Muunnosprosessin voi todeta olleen hyödyllinen, koska sen aikana paljastui ongelmia sekä SMS:n rakennekuvauksessa että itse standardin määrittelyssä. Tulosten avulla SMS:n koodausta voidaan kehittää edelleen. Lopuksi tarkastellaan standardien käytöstä yleisesti saatavia hyötyjä ja mahdollisuuksia soveltaa niitä Kotuksen sanakirjatyöhön.
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(2012)The standard system of dyadic cubes in the Euclidean space R^n is a collection of half-open cubes of different sizes such that the cubes of every size partition the space and every cube is a finite union of smaller cubes. The construction of this system is very simple but it does rely strongly on the geometrical properties of the space R^n. Hence, if we give up most of the geometrical properties of the space R^n, the construction of sets with similar properties becomes more complicated. In this paper, we show that there exist dyadic cubes in general doubling metric spaces. We do this using certain maximal sets of points and a carefully defined partial order of those points. We look at several different dyadic systems first in R^n and then in general doubling metric spaces. We start by proving some basic results related to doubling metric spaces and other related topics and continue by introducing the standard, randomized and adjacent systems of dyadic cubes in R^n. Then, in a general doubling metric space, we construct a system of sets that has similar properties as the standard system of dyadic cubes in R^n. We call also these sets cubes although they are not cubes in the usual sense of the word. After this, we add a probabilistic angle to the constructed system by randomizing them and look at two different random systems. Lastly, we look at some applications of the random dyadic systems. Our goal is to introduce a new simpler way of randomizing dyadic systems in doubling metric spaces and show that this is an effective way of randomizing the systems. We show this by proving that every point in the space has only a small probability of ending up near the boundary of a cube of given size. This property has an interesting application since we can use it to construct systems of Hölder-continuous spline functions in doubling metric spaces. It is still an open problem to prove whether there exist systems of Lipschitz-continuous spline functions in every doubling metric space. We do not know the answer to this problem but we show that at least there exist systems of Hölder-continuous spline functions of every exponent η ∈ (0,1) in every doubling metric space.
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(2016)With the rapid development of information technology, the network is playing a more and more important role in our life and penetrate to every corner of our life, such as responsible for computing and transacting in business industries, and make great contribution for social communication. However, at the same time, more and more network attacks appears and seriously endanger the security of network. Including the threads for wired network and wireless network. In this thesis, we rst talk about network security, including wired network security and wireless security, we discuss the current threads and attacks we face for the wired network and wireless network, then we introduced the current solution for these threads and attacks.At last,we demonstrate the whole process of session cookie hijacking by manually perform it.We proposed our solution which called random cookie protocol, and we did experiments to compare the performance with HTTP.
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(2023)The Ising model is a classic model in statistical physics. Originally intended to model ferromagnetism, it has proven to be of great interest to mathematicians and physicists. In two dimensions it is sufficiently complex to describe interesting phenomena while still remaining analytically solvable. The model is defined upon a graph, with a random variable, called a spin, on each vertex. Other random variables may be defined as functions of spins. A classic problem of interest is the correlation of these random variables. A continuum analogue of the Ising model is possible through considering the scaling limit of the model, as the graph taken to approximate some domain e.g. in the complex plane or a torus. The core of this work is an exposition upon one method of calculating correlations of a random variable called a fermion defined in terms of spins and disorder random variables. The method is called Bosonization and associates correlations of some random variables to correlations of the Gaussian Free Field (GFF). The GFF is a random distribution, which approximately functions as a gaussian random variable whose covariance structure is given by Green's function. A result known as the Pfaffian-Hafnian identity is covered, to provide an example of an identity which may be derived using Bosonization on a continuum planar Ising model. A similar result is also presented on the Torus, using elliptic functions. These results are not original, but we present the only -- to us -- known explicit proofs based on hints from others. In the latter half of the work, Bosonization is approached using Random Current representation. Random currents give weights to each edge of the graph of the Ising model. Two other models are introduced: Alternating flows and the Dimer model. There are equivalence relations between the configuration of the Ising model, the Nesting Field of a random current and the height functions of an alternating flow and a dimer cover. Using these, correlations of random variables of the Ising model are given in terms of the height function of the Dimer model. The height function of the Dimer model is a discrete analogue of the GFF.
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(Helsingin yliopistoHelsingfors universitetUniversity of Helsinki, 2010)In this thesis, I study the changing ladscape and human environment of the Mätäjoki Valley, West-Helsinki, using reconstructions and predictive modelling. The study is a part of a larger project funded by the city of Helsinki aming to map the past of the Mätäjoki Valley. The changes in landscape from an archipelago in the Ancylus Lake to a river valley are studied from 10000 to 2000 years ago. Alongside shore displacement, we look at the changing environment from human perspective and predict the location of dwelling sitesat various times. As a result, two map series were produced that show how the landscape changed and where inhabitance is predicted. To back them up, we have also looked at what previous research says about the history of the waterways, climate, vegetation and archaeology. The changing landscape of the river valley is reconstructed using GIS methods. For this purpose, new laser point data set was used and at the same time tested in the context landscape modelling. Dwelling sites were modeled with logistic regression analysis. The spatial predictive model combines data on the locations of the known dwelling sites, environmental factors and shore displacement data. The predictions were visualised into raster maps that show the predictions for inhabitance 3000 and 5000 years ago. The aim of these maps was to help archaeologists map potential spots for human activity. The produced landscape reconstructions clarified previous shore displacement studies of the Mätäjoki region and provided new information on the location of shoreline. From the shore displacement history of the Mätäjoki Valley arise the following stages: 1. The northernmost hills of the Mätäjoki Valley rose from Ancylus Lake approximately 10000 years ago. Shore displacement was fast during the following thousand years. 2. The area was an archipelago with a relatively steady shoreline 9000 7000 years ago. 8000 years ago the shoreline drew back in the middle and southern parts of the river valley because of the transgression of the Litorina Sea. 3. Mätäjoki was a sheltered bay of the Litorina Sea 6000 5000 years ago. The Vantaanjoki River started to flow into the Mätäjoki Valley approximately 5000 years ago. 4. The sediment plains in the southern part of the river valley rose from the sea rather quickly 5000 3000 years ago. Salt water still pushed its way into the southermost part of the valley 4000 years ago. 5. The shoreline proceeded to Pitäjänmäki rapids where it stayed at least a thousand years 3000 2000 years ago. The predictive models managed to predict the locations of dwelling sites moderately well. The most accurate predictions were found on the eastern shore and Malminkartano area. Of the environment variables sand and aspect of slope were found to have the best predictive power. From the results of this study we can conclude that the Mätäjoki Valley has been a favorable location to live especially 6000 5000 years ago when the climate was mild and vegetation lush. The laser point data set used here works best in shore displacement studies located in rural areas or if further specific palaeogeographic or hydrologic analysis in the research area is not needed.
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(2012)In this Master's thesis the incidence of soil water repellency on coastal dune sands in boreal environment is investigated. The focus is on evaluating the severity of occurring hydrophobicity and identifying the factors causing it. Soil water repellency is a reduction in the rate of wetting caused by the presence of hydrophobic coatings on soil particles. Hydrophobic organic compounds derive from certain fungal species, surface waxes of plant leafs, exudates produced by plant roots and soil microbes, and decomposing organic litter. Surfaces with a surface free energy less than the surface tension of water, are hydrophobic in character. Weak infiltration leads to increased surface runoff, which in turn enhances erosion by water and wind. The research areas are Vattajanniemi in Lohtaja and Yyteri in Pori. Both dune areas are located on the western coast of Finland. In total 230 soil samples were collected from the research areas. The samples were dried in 50 - 55 °C temperature and analyzed in laboratory. The samples were divided in subgroups based on the vegetation growing on the sample sites. On the investigated white dunes the dominating species was sea lyme grass and on the grey dunes either sea pea or lichens. On the forested dunes the vegetation was either pine tree forest or fertile deciduos forest. A few samples were also taken from deflation surfaces between the dunes. Additionally, some of the grey dunes were recently burned at the time of the sampling, and the research is also focusing on the effect of fire on soil water repellency. The samples from Vattajanniemi were collected from the surface layer of the soil and the samples from Yyteri were collected from different layers of the soil profile. The sampling depths in Yyteri were: 0 - 5 cm, 5 - 10 cm, 10 - 20 cm, 20 - 30 cm, 30 - 40 cm and 40 - 50 cm. The severity of water repellency was assessed by measuring Water Drop Penetration Time (WDPT) in seconds. The organic carbon content of the soil samples was measured using loss on ignition analysis. Part of the samples were additionally sieved, and grain size parameters were calculated from the results. Soil water repellency was a common feature on the investigated areas. Especially strong water repellency was found on dunes covered by lichens. The surface soil samples taken from the forested dunes and burned areas were also all water repellent. The bare deflation surfaces and the white dunes covered by sparse vegetation were mostly hydrophilic or slightly hydrophobic in character. The organic carbon content in the soil samples was principally less than 1 %. There was a strong positive correlation between water repellency and the amount of organic matter, but the best individual explaining variable according to regression analysis was the type of vegetation. The best results were gained with a general linear model when the explaining variables were the type of vegetation, the amount of organic carbon as first and second degree equation and the covariation between these variables. The model explains approximately 75 % of the variation in the WDPT test results. The texture was very similar between the samples. Standard deviation was the only statistically significant sand-sorting characteristic, and it had a weak correlation with the WDPT test results. Water repellency decreases with increasing depth principally because the amount of organic matter decreases. The general linear model explained 97 % of the variation in the WDPT test results when the explaining variables were the type of vegetation, the amount of organic carbon, the sampling depth and the covariation between the variables.
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(2014)Taalikkala megaxenolith is a fragment of the Wiborg rapakivi granite batholith roof. It is situated in Lappeenranta and has been exposed by the erosion. The geology of the area is exceptional because of the supracrustal rocks that have stratified on the bedrock before the fragment has detached from the roof of the magma chamber, flipped sidewise and sunk to the chamber. Quartz arenite has stratified atop of Svecofennian granodiorite and mica schist. Atop the discontinous quartz arenite there have formed rapakivi assosiated mafic and felsic volcanic and subvolcanic rocks. Based on lithologic, petrografic and geochemical studies, the volcanic rocks of the Taalikkala megaxenolith can be categorized in two main groups - the mafic and the felsic series. In both groups there is lithologic, petrologic and geochemical variation. In the mafic series the rocks are mainly tholeiitic whithin plate basalts. The felsic series rocks are acic volcanic and pyroclastic rocks. Geochemically, the felsic series rocks correlate both oxidized and reduced A-type granites. The stratigraphic thickness of Taalikkala supracrustal assosiation is about 1500 m and it is very similar to supracrustal rock assosiation in the Island of Suursaari (Russia) southwest of Wiborg batholith. A TIMS-data of the rapakivi porphyry shows that the crystallization age of felsic series is 1638 ± 3 Ma. The Wiborg rapakivi granite batholith represents a magma chamber that has erupted in several periods in Mesoproterozoic Era forming volcanic rocks that can be seen in the Taalikkala megaxenolith and the Island of Suursaari. The magma chamber (Wiborg batholith), the erupting channels (diabase dikes) and relics of lavas and pyroclastic stratas (bimodal volcanic rocks in Taalikkala and Suursaari) can all be seen today as reminders of the volcanic activities in Mesoproterozoic Era in southern Finland.
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(2016)Printing drug laden polymer layers is one way to fabricate personalized drug delivery systems. To assure dosage and drug release profiles it is crucial to characterize topography of polymer layers and layer adhesion in multilayer structures. We use our custom build scanning white light interferometer (SWLI) to non-destructively characterize layer thickness, surface roughness and layer adhesion of multilayered drug delivery system. For this work we characterized four drug delivery systems with our SWLI. One of these drug delivery system was characterized inside of microfluidic channel during water discharge. We demonstrated our capability to non-destructively characterize layer thickness of multilayered samples, characterize polymer interface topology with high resolution and distinct between adhesion and delamination on polymer/polymer and polymer/glass interfaces. We also showed our capability to characterize these features in microfluidic channels. We thus demonstrated the possibility to use our device in quality control of tailored drug delivery systems e.g. printed drugs.
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(Helsingin yliopistoUniversity of HelsinkiHelsingfors universitet, 2008)The aim of this thesis was to study the crops currently used for biofuel production from the following aspects: 1. what should be the average yield/ ha to reach an energy balance at least 0 or positive 2. what are the shares of the primary and secondary energy flows in agriculture, transport, processing and usage, and 3. overall effects of biofuel crop cultivation, transport, processing and usage. This thesis concentrated on oilseed rape biodiesel and wheat bioethanol in the European Union, comparing them with competing biofuels, such as corn and sugarcane-based ethanol, and the second generation biofuels. The study was executed by comparing Life Cycle Assessment-studies from the EU-region and by analyzing them thoroughly from the differences viewpoint. The variables were the following: energy ratio, hectare yield (l/ha), impact on greenhouse gas emissions (particularly CO2), energy consumption in crop growing and processing one hectare of a particular crop to biofuel, distribution of energy in processing and effects of the secondary energy flows, like e.g. wheat straw. Processing was found to be the most energy consuming part in the production of biofuels. So if the raw materials will remain the same, the development will happen in processing. First generation biodiesel requires esterification, which consumes approximately one third of the process energy. Around 75% of the energy consumed in manufacturing the first generation wheat-based ethanol is spent in steam and electricity generation. No breakthroughs are in sight in the agricultural sector to achieve significantly higher energy ratios. It was found out that even in ideal conditions the energy ratio of first generation wheat-based ethanol will remain slightly under 2. For oilseed rape-based biodiesel the energy ratios are better, and energy consumption per hectare is lower compared to wheat-based ethanol. But both of these are lower compared to e.g. sugarcane-based ethanol. Also the hectare yield of wheat-based ethanol is significantly lower. Biofuels are in a key position when considering the future of the world's transport sector. Uncertainties concerning biofuels are, however, several, like the schedule of large scale introduction to consumer markets, technologies used, raw materials and their availability and - maybe the biggest - the real production capacity in relation to the fuel consumption. First generation biofuels have not been the expected answer to environmental problems. Comparisons made show that sugarcane-based ethanol is the most prominent first generation biofuel at the moment, both from energy and environment point of view. Also palmoil-based biodiesel looks promising, although it involves environmental concerns as well. From this point of view the biofuels in this study - wheat-based ethanol and oilseed rape-based biodiesel - are not very competitive options. On the other hand, crops currently used for fuel production in different countries are selected based on several factors, not only based on thier relative general superiority. It is challenging to make long-term forecasts for the biofuel sector, but it can be said that satisfying the world's current and near future traffic fuel consumption with biofuels can only be regarded impossible. This does not mean that biofuels should be rejected and their positive aspects ignored, but maybe this reality helps us to put them in perspective. To achieve true environmental benefits through the usage of biofuels there must first be a significant drop both in traffic volumes and overall fuel consumption. Second generation biofuels are coming, but serious questions about their availability and production capacities remain open. Therefore nothing can be taken for granted in this issue, expect the need for development.
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(2012)This research describes how railway and rail yard capacity can be determined using aerial image interpretation. The study also describes how parameters used in capacity modelling can be extracted from aerial images. Additionally, commonly used railway capacity modelling methods are described in the study's method section. The interpretation and modelling methods used in this study were tested by interpreting structures of an aerial image taken from the Tampere rail yard. The rail yard's classification and receiving capacity was then estimated a method based on an artificial time schedule on Excel worksheet. The accuracy of the image interpretation and capacity estimation were evaluated using literary sources and interviewing personnel of the rail yard. In railway capacity modelling, the most important interpretation targets were concluded to be the evaluation of the maximum route speed, maximum length of train, axel weight limitations, and determination of the length of block sections on the route. The attributes related to speed, weight and length were concluded to be interpretable by studying the rail curvature, structure and switch types used on the route. The type of rolling stock and its freight spotted at the route were also concluded to be good interpretation keys for these purposes. Locating the signal posts by their shadows and balises related to them was concluded to be useful for the interpretation of the block lengths. Interpreting the arrival inspections process and the size and usage of the work resources in the rail yard was concluded to be important in rail yard capacity modelling. The usage of the rail yard structures and yards could be successfully interpreted based on the relative locations of the structures within the yard and the arrangement of the switches. The determination of the most likely traffic directions from the classification yard, accurate interpretation of the usage length of the storage tracks, number of switch engines operating in the yard and understanding of the inspection processes were concluded to be difficult to extract from the information derived from image interpretation. However, the most probable usage and performance of the switch engines could be accurately estimated based on interpretation of the switch leads and switches. The rail yard capacity estimation method based on a manual time schedule was concluded to be suitable for the theoretical capacity estimation of the rail yards. The method was able to produce accurate performance statistics after the inspection process was changed to represent real-life processes used in the yard. The capacity estimation method used in this study can be applied to any rail yard representing a configuration similar to the Tampere rail yard.
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(Helsingin yliopistoHelsingfors universitetUniversity of Helsinki, 2007)
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(2014)The forms of iron, especially iron oxides, are significant in the geochemical cycle of phosphorus and many trace elements in the sediment. In aerobic conditions, the iron oxides of the sediment bind phosphorus and trace elements. In anaerobic conditions, on the other hand, iron oxides dissolve, in which case the bound trace elements and phosphorus are released. When phosphorus is released from the sediment and migrates to a water column, this may further aggravate the eutrophication problem of the Baltic Sea through internal load. Thus, the goal of this thesis is to clarify and gain new information on how the forms of iron and their amount vary in the sea areas of the Baltic Sea with different oxygen conditions and what significance this may have with regard to the eutrophication of the Baltic Sea. Water and sediment samples were collected in April 2006 on board the research vessel R/V Aranda and, in October 2006, on board the research vessel Geomari. The sample stations were situated in the Bothnian Bay, the Bothnian Sea, the northern part of the Baltic Sea Proper, and the Gulf of Finland. Water and sediment samples were collected from several different depths. Of the water samples, temperature and salinity as well as the concentrations of oxygen, hydrogen sulphide and phosphate phosphorus were determined. In all the sample stations, the oxidation-reduction potential and pH of the sediment were measured. Of the sediment samples, the overall concentrations of iron, manganese, phosphorus, sulphur, nitrogen, and carbon as well as the forms of iron were analysed. The analysis of the forms of iron was carried out with a sequential leaching method, in which the four separated forms were: 1) iron bound in carbonates (siderite and ankerite) or iron bound in acid-volatile sulfide (AVS), 2) easily reduced iron oxides (ferrihydrite and lepidocrite), 3) reducing iron oxides (goethite, hematite, akaganeite) and 4) magnetite. The results show that the different oxygen conditions in the water near the bottom in the studied stations can be seen as variation of the forms of iron in the sediment, especially regarding iron oxide concentrations. The sediments of the Bothnian Bay and Bothnian Sea have, due to good oxygen conditions in the water near the bottom, plenty of easily reduced and reducing iron oxides, especially in the sediment's surface layers. Instead, in the sulfidic sediments of the occasionally anaerobic Gulf of Finland and especially the northern part of the Baltic Sea Proper, which has been anaerobic for a long time, there are few easily reduced and reducing iron oxides. From the point of view of internal load and the eutrophication of the Baltic Sea, the aerobic sediments containing plenty of iron oxides in the stations of the Bothnian Bay and the Bothnian Sea could act as binders of phosphorus and other trace elements. Instead, in the station of the Gulf of Finland the amount of iron oxides in the sediment can vary due to the occasional anaerobic state and, in the station in the northern part of the Baltic Sea Proper that has been anaerobic for a long time, there are few phosphorus binding iron oxides, in which case phosphorus is released from the sediment to the water and can mix with the productive layer to be used by algae.
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(2012)Kiviniemi intrusion is located in Rautalampi, Central Finland. In addition to a garnet-bearing fayalite ferrogabbro with elevated scandium concentrations, the intrusion consists of a wider area of heterogeneous ferrogabbro, leucogabbro and diorite. The intrusion is located in the northeastern part of the Central Finland Granitoid Complex, right next to the primitive arc-type rocks of the Savo Belt. The mafic intrusion is surrounded by a porphyritic granite. This study is based on the results of field work (field observation reports and samples) and analyses made by Geological Survey of Finland, and also on the reports of nine drill holes (combined length 1251,50 m) drilled during the years 2008-2010. Whole-rock geochemical analyses were made with the XRF-method for the main oxides (n=74) and ICP-MS for the trace elements (n=28). Petrographic studies were based on 51 thin sections, from which 12 were chosen for electron microprobe analysis, in order to examine the compositions of solid solution series minerals and map the distribution of some trace elements. Concordant age results based on the U-Pb system are reported for the garnet-bearing fayalite ferrogabbro (TIMS, 1857±2 Ma) and the country rock granite (LA-ICP-MS, 1859±9 Ma). Neodymium isotope compositions were also determined at the Geological Survey of Finland. The initial neodymium epsilon values are +0,1 for ferrogabbro and -2,4 for granite. The ferrogabbro of the main deposit is coarse-grained, enriched in iron (FeOtot 11-40%), scandium (130-281 ppm) and zirconium (235-5210 ppm). Locally, the concentrations of titanium and phosphorus can also be high (max TiO2 3,6% and P2O5 1,8%). The main rock-forming minerals are fayalite, almandine, ferroaugite/ferrohedenbergite, hastingsite/actinolite and plagioclase. Potassium feldspar, quartz, ilmenite, fluorapatite and zircon are found as accessory minerals. The high pressure iron-manganese silicate mineral pyroxferroite was revealed by microprobe analysis. Main deposit is surrounded by small to medium-grained ferrogabro/diorite, which has a slightly heterogeneous mineral composition and texture. Small shreds of leucogabbro are located in the proximity of main deposit. The study of the geochemical features suggests that the distribution of trace elements and REE is uniform throughout the Kiviniemi intrusion, including the country rock granite. The high concentration of iron refers to a highly evolved tholeiitic magma, which originated from the mafic melts of upper mantle and emplaced into the lower crust. High concentrations of some rare earth elements (Hf, Y, Sc) and locally elevated percentages of alkali metals may indicate crustal contamination during magma ascent. The age of the Kiviniemi intrusion and its country rock represent the magmatism of the post-kinematic stage of the Svecofennian orogeny (1880-1860 Ma). The presence of garnet and pyroxferroite in the ferrogabbro may reflect high crystallization pressures (7-12 kbar). To examine the enrichment of scandium and zirconium, further isotope measurements (Hf, Sr) are needed. Modeling the contamination and magma mixing as well as investigating the effects of possible fluid activity are proposed.
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(2016)Sää vaikuttaa moneen eri yhteiskunnan osa-alueen toimintaan, kuten liikennejärjestelmiin. Vaikeat sääolosuhteet heikentävät sekä liikennejärjestelmien täsmällisyyttä että turvallisuustasoa, ja aiheuttavat siten palvelutason alenemista. Rautatieliikenteessä vaikeat sääolosuhteet voivat aiheuttaa merkittäviä myöhästymisiä ja mittavia taloudellisia menetyksiä, mistä johtuen niiden tarkastelu on tärkeää. Tässä pro gradu -tutkielmassa tarkasteltiin, mitkä sääilmiöt vaikuttavat rautatieliikenteen täsmällisyyteen Suomessa tarkastelemalla vallitsevaa säätilaa tilanteissa, joissa rautatieliikenteen kaukoliikenteessä on havaittu myöhästymisiä tammikuun 2013 ja maaliskuun 2016 välisellä ajanjaksolla. Tarkastelun avulla pyrittiin myös selvittämään, mikä tai mitkä sääilmiöt aiheuttavat eniten rautatieliikenteen myöhästymisiä, ja mitkä tekijät vaikuttavat kyseessä olevan sääilmiön ennustettavuuteen ja sen kehittämiseen. Aineistona käytettiin VR Group Oy:ltä (Skyttä, 2016) saatua rautatieliikenteen täsmällisyystilastoa, johon on kirjattu säähän liittyville syykoodeille sää ja lumieste merkityt viiveet ja myöhästymiset. Osin täsmällisyystietoja on haettu myös Liikenneviraston avoimen rajapinnan Digitraffic-palvelusta käyttöluvalla Creative Commons Nimeä 4.0. Vallitsevan säätilan tarkasteluun ja myöhästymisten luokitteluun sääilmiöittäin käytettiin Ilmatieteen laitoksen ennusteita, varoituksia ja havaintoja. Tarkastelun perusteella merkittävimpiä rautatieliikenteen täsmällisyyteen vaikuttavia sääilmiöitä ovat lumisade ja pakkanen. Eniten löydettiin lumisateeseen liittyviä myöhästymistapauksia (111 kappaletta). Lumisateet liittyivät useimmiten keskileveysasteiden matalapaineiden okluusiorintamiin, joissa havaittiin suurimmat lumikertymät ja merkittävimmät myöhästymiset. Myös vesistöjen nostattamilla ja rannikkokonvergenssin voimistamilla lumikuuroilla on vaikutusta rautatieliikenteen täsmällisyyteen. Lumisateiden ennustamisessa ja vaikutusten ennakoinnissa tärkeintä on tunnistaa tapaukset, joissa luntaa kertyy laajoille ja rautatieliikenteen kannalta kriittisille alueille.
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(Helsingin yliopistoUniversity of HelsinkiHelsingfors universitet, 2007)This study presents an analysis of the calendars of lucky and unlucky days by the application of the Rayleigh Test. In these ancient Egyptian texts each day of the year is assigned a so-called prognosis, which can be 'good' or 'bad' for each part of the day. The purpose of the analysis is to find out, whether the lucky and unlucky days were randomly or periodically distributed within the year. The period of 29.5 days found in the prognoses with a considerably high significance, represents the effect of the synodic month to the calendars. The found periods of 7.5 and 30 days suggest that the ancient Egyptian civil calendar also had influence on determining the prognoses. Other significant periods are also found in the time series, possibly based on a numerological meaning. The period of 2.85 is possibly a sign of an ancient Egyptian observation of the star Algol, which is one of the best known eclipsing variable stars. If this were the case, it could be the oldest known determination of the period of a variable star in history.
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(2018)This thesis presents a ray-tracing based method for performing polarized radiative transfer in arbitrary spacetimes and a numerical implementation of said method. This method correctly accounts for general relativistic effects on the propagation of radiation, and the polarized im- ages and spectra it produces can be directly compared with observations. Thus it is well suited for studying systems where relativistic effects are significant, such as compact astrophysical objects. The ray-tracing method is based on several approximations, which are discussed in depth. The most important one of these is the geometric optics approximation, which is derived starting from Maxwell’s equations. In the geometric optics approximation, high frequency radiation is described as amplitudes or intensities which are propagated along geodesic rays. Additional assumptions about the properties of the radiation field allow describing it and its interaction with matter using the formalism of kinetic theory, which leads to a simple transfer equation along rays. This transfer equation is valid in arbitrary spacetimes, and forms the basis for the ray-tracing method. The ray-tracing method presented in this work and various similar methods described in the literature are not suited for analytic computations using realistic models. Instead numerical methods are needed. Such numerical methods are implemented in a general fashion in the Arcmancer library (paper in preparation), of which large parts were implemented as a part of this work. The implementation details of Arcmancer are described and its features are compared to those available in other similar codes. Tests of the accuracy of the numerical methods as well as example applications are also presented, including a novel computation of a gravitational lensing event in a binary black hole system. The implementation is found to be correct and easily applicable to a variety of problems.
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(2013)With the increasing expectations of mobile device users, GSMA has initiated Rich Communication Suite, a collaborative effort with leading mobile operators to enhance the deployment of IP Multimedia Subsystem services and bring it to the mass market. RCS provides a inter-operable and convergent communication suite to explore and enrich IMS multimedia services. This thesis provides an extensive overview of IMS and RCS architectures, messaging and transport protocols and usage of Session Initiation Protocol as rendezvous signaling. It describes how RCS uses IMS networks and enriches the IMS services and communications. Although all releases of RCS included file transfer as one of its communication services, those did not address issues associated with file transfer to multiple end users. This thesis describes elaborately how one-to-one file transfer can be done, how it can be expanded to multiple users and pros and cons of different mechanisms. It also shows the usage of RCS to enrich file transfer mechanisms. The tests in the scope of this thesis were executed using devices with various network and CPU capabilities. Finally, potential future works have been discussed. In the examples, all real world identities (domain name, URIs, server name etc.) have been replaced by mock identities.
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(2014)Useilla organisaatioilla on tarve yhdistää omia tietokantoja ulkopuolisten tietovarastoiden tietoihin. Yhteistoiminta voidaan toteuttaa siten, että ohjelmoijat selvittävät kutsurajapinnat ja räätälöivät ohjelmansa niiden mukaisiksi. Tämä lähestymistapa on kuitenkin hyvin teknologiapainotteinen. Jos rajapinnat muuttuvat, tulee myös ohjelmakoodia muuttaa. Tarvitaan standardeja ja niihin sitoutumista, jotta kitka eri toimijoiden välillä saadaan minimoitua. Erityisesti avoimissa ympäristöissä standardeihin sitoutuminen korostuu. RDF on standardoitu tietomalli, joka voi toimia linkkinä heterogeenisten tietovarastojen välillä. RDF-muotoisen datan määrä onkin kasvanut viime vuosina voimakkaasti, mikä korostaa tehokkaiden ja skaalautuvien talletusratkaisujen tärkeyttä. Tässä tutkielmassa lähestytään RDF-tietomallia linkitetyn datan näkökulmasta. Linkitetty data on alkanut herättää kiinnostusta eri toimijoiden keskuudessa, ja useat organisaatiot ovat jo julkaisseet dataa linkitetyn datan periaatteiden mukaisesti. Linkitettyä dataa syntyy, kun RDF-muotoista dataa linkitetään muualla sijaitseviin resursseihin. Tutkielmassa esitetään tapaustutkimus havainnollistavana kuvauksena siitä, miten RDF-muotoista dataa voi syntyä. RDF-tietomallin mukaista dataa voidaan muodostaa rakentamalla RDF-kerros olemassa olevien tietokantojen päälle tai käyttämällä RDF-tietokantaa tietovarastona. Jos RDF-muotoiselle datalle luodaan oma tietovarasto, on tärkeää ymmärtää eri talletusratkaisujen eroja. Tämä tutkielma antaa yleiskuvan olemassa olevista RDF-muotoisen datan tietokantaratkaisuista. On kuitenkin huomattava, että tutkielmassa esitettyjen ratkaisujen joukko ei ole tyhjentävä. Keskusmuistipohjaisista, relaatiotietokantapohjaisista ja natiiveista RDF-tietokannoista on kuvattu valitut järjestelmät, jotta yleiskuva jokaisesta ryhmästä voidaan muodostaa. RDF-tietokannan optimaaliseen arkkitehtuuriratkaisuun vaikuttavia asioita on useita, ja niihin kuuluvat talletettavan datan muoto ja määrä, tietokantaan kohdistuvat kyselyt ja kyselyjen vasteaikoihin liittyvät vaatimukset.
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(2016)Klassinen web muodostuu linkitetyistä dokumenteista. Sen rinnalle on muodostunut linkitetyistä tietojoukoista koostuva semanttinen web, jonka tarkoituksena on tehdä verkon sisällöstä koneellisesti ymmärrettävää semanttisen metatiedon avulla. Verkon yhteenlinkittyneitä tietojoukkoja kutsutaan myös linkitetyksi dataksi. RDF (Resource Description Framework) muodostaa pohjan semanttiselle webille ja linkitetylle datalle. RDF on formaattiriippumaton tietomalli semanttisen metatiedon liittämiseksi web-resursseihin. Sen tietomallissa resurssien ominaisuuksia ja yhteyksiä mallinnetaan subjekti-predikaatti-objekti -kolmikoilla. Voimakkaamman päättelyn ja sovellusten yhteentoimivuuden mahdollistamiseksi RDF-dataa voi formaalisti kuvailla ja luokitella ontologioiden avulla. OWL (Web Ontology Language) on hallitseva kieliperhe web-ontologioiden määrittelyyn. Lisäksi RDF-muotoiseen tietoon voi tehdä kyselyjä SPARQL-kyselykielellä (SPARQL Protocol and RDF Query Language). Tutkielmassa perehdytään RDF-muotoisen tiedon hallintaan ja siihen liittyviin teknologioihin. Erityisesti selvitetään hajallaan olevan RDF-muotoisen tiedon hallintaan liittyviä erityispiirteitä, kuten ontologioiden yhteensovittamista ja useisiin lähteisiin tehtyjä kyselyitä. Suoritamme myös kaksi koekyselyä hajallaan olevien lähteiden kyselyn havainnollistamiseksi.
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