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Software development is massive industry today. Billions of dollars are spent and created on im- material products, and the stakes are very high. The failure modes of commercial software projects have been extensively studied, motivated by the large amounts of money in play. Meanwhile, failures in open source projects have been studied less, despite open-source projects forming a massive part of the computing industry ecosystem today. As more and more companies depend on open-source projects, it becomes imperative to understand the motivations and problems in the volunteer-staffed projects. This thesis opens with an introduction into the history of open source, followed by an overview of the actual day-to-day minutia of the tools and processes used to run a project. After this background context has been established, the existing body of research into open-source motivation is surveyed. The motivation of the people working on these projects has been studied extensively, as it seems illogical that highly-skilled volunteers pour their efforts into supporting a trillion-dollar industry. The existing body of motivation research establishes why people work on open-source projects in general, but it does not explain which projects they choose to work on. Developers drift between projects unguided, as they are free to choose where they allocate their time and energies. The contributions into open-source projects follow a Pareto distribution, and the majority of projects never manage to attract large amounts of contributors. Others lose steam after an internal or external shock drives away the contributors. To explore the latter phenomenon, four case studies are done into crises various open-source projects have faced, and how the actions of project leadership has affected the outcome for the project. Two of the shocks are caused by illegal activities by a project member, and two are caused by social disagreements.

The presence of 1/f type noise in a variety of natural processes and human cognition is a well-established fact, and methods of analysing it are many. Fractal analysis of time series data has long been subject to limitations due to the inaccuracy of results for small datasets and finite data. The development of artificial intelligence and machine learning algorithms over the recent years have opened the door to modeling and forecasting such phenomena as well which we do not yet have a complete understanding of. In this thesis principal component analysis is used to detect 1/f noise patterns in human-played drum beats typical to a style of playing. In the future, this type of analysis could be used to construct drum machines that mimic the fluctuations in timing associated with a certain characteristic in human-played music such as genre, era, or musician. In this study the link between 1/f-noisy patterns of fluctuations in timing and the technical skill level of the musician is researched. Samples of isolated drum tracks are collected and split into two groups representing either low or high level of technical skill. Time series vectors are then constructed by hand to depict the actual timing of the human-played beats. Difference vectors are then created for analysis by using the least-squares method to find the corresponding "perfect" beat and subtracting them from the collected data. These resulting data illustrate the deviation of the actual playing from the beat according to a metronome. A principal component analysis algorithm is then run on the power spectra of the difference vectors to detect points of correlation within different subsets of the data, with the focus being on the two groups mentioned earlier. Finally, we attempt to fit a 1/f noise model to the principal component scores of the power spectra. The results of the study support our hypothesis but their interpretation on this scale appears subjective. We find that the principal component of the power spectra of the more skilled musicians' samples can be approximated by the function $S=1/f^{\alpha}$ with $\alpha\in(0,2)$, which is indicative of fractal noise. Although the less skilled group's samples do not appear to contain 1/f-noisy fluctuations, its subsets do quite consistently. The opposite is true for the first-mentioned dataset. All in all, we find that a much larger dataset is required to construct a reliable model of human error in recorded music, but with the small amount of data in this study we show that we can indeed detect and isolate defining rhythmic characteristics to a certain style of playing drums.

Atmospheric aerosols affect the Earth's radiative balance, visibility and human health. Therefore the formation processes and growth of these particles are important and should be studied to understand how human and natural processes affects these processes. One poorly understood and relatively little studied part of aerosols is particulate organic nitrates (pONs). These pONs are mostly formed during nighttime when NOx, mainly emitted from fossil fuel combustion and industrial processes, and volatile organic compounds (VOCs), from both natural and anthropogenic sources, reacts in the atmosphere. The quantification of these pONs is still hard due to instrumental restrictions, although much improvement has happened during recent years. One main reason for these challenges is the difficulty to separate inorganic nitrates from organic nitrates with real-time instruments. During this work, we generated pure pON in well controlled laboratory conditions and sampled it with an Aerosol Mass Spectrometer (AMS), an instrument widely used for measuring the chemical composition of atmospheric aerosols. We used four different pON precursors to generate pON. I investigated the fragmentation patterns of pON detected by the AMS, utilizing the high resolution of the newest model of the AMS. As older versions of the AMS has difficulties to separate nitrate-containing organic fragments due to lower resolution than the AMS I used, I was able to study pON mass spectrum with better resolution than anyone before me. I found mass spectral differences for the different pON precursors, and was able to find unique fragments for some of the pON precursors that possibly can be used as marker fragments.

Azulen, bicyklo[5.3.0]dekapentaen, är ett fullständigt konjugerat kolväte, som förekommer i olika växter. Femringen i det mörkblåfärgade kolvätet är klart elektronrikare än sjuringen, vilket leder till att positionerna i azulen har olika reaktivitet. Utöver att funktionalisera kommersiellt tillgänglig azulen är det även möjligt att införa olika substituenter på fem- och/eller sjuringen i samband med ringslutningen till azulen. De tre huvudsakliga framställningsmetoderna baseras på lämpligt substituerade fulven-, cykloheptatrien- eller bensenderivat. I det här arbetet presenteras olika kända metoder för att ringsluta och funktionalisera grundstommen i azulen, vilka kan användas för att erhålla flersubstituerade azulenderivat. Målet med arbetet var att utveckla en syntesrutt för 1,2,6-trisubstituerade azulenderivat med potentiell tillämpning som peptidmimetika dvs. en liten molekyl som kan åstadkomma samma biologiska aktivitet som en viss peptid trots att molekylen saknar peptidstruktur. De funktionella grupperna som infördes i 1-, 2- och 6-positionen kan ersättas med nya substituenter, vilket gör det möjligt att erhålla flera olika prekursorer till målmolekylen. 1,6-Disubstituerade azulenderivat framställdes med hjälp av Rh-katalyserad ringslutning av 4- brom-4-(4-klorfenyl)-1-diazo-2-butanon, som erhållits från 4-klorbensaldehyd. Eftersom en del azulenderivat var instabila och funktionaliseringen av 2-positionen misslyckades, utvecklades en alternativ syntesrutt. I den nya rutten användes cyklopentadienylanjon och 4-metylpyridin, vilket gav 6-substituerade azulenderivat. Funktionaliseringen av 2-positionen i 6-metylazulen fungerade efter flera misslyckade ansatser. Den eftersträvade målmolekylen nåddes inte men olika 6-, 1,6-, 2,6-, 1,2,3-, 1,2,3,4-substituerade azulenprekursorer till den eftersträvade målmolekylen erhölls.

Free and open source software development is an alternative to traditional software engineering as an approach to the development of complex software systems. It is a way of developing software based on geographically distributed teams of volunteers without apparent central plan or traditional mechanisms of coordination. The purpose of this thesis is to summarize the current knowledge about free and open source software development and explore the ways on which further understanding on it could be gained. The results of research on the field as well as the research methods are introduced and discussed. Also adapting software process metrics to the context of free and open source software development is illustrated and the possibilities to utilize them as tools to validate other research are discussed.

Optical parametric oscillators (OPO) are sources of coherent light, often used to produce laser like light in wavelength regions where ordinary laser operation is challenging. In terms of chemistry, most attractive such a region is in mid-infrared, where strong fundamental vibrational transitions occur. OPOs are based on nonlinear polarization, which some materials exhibit when radiated with strong coherent light and effectively allow transferring optical power from one wavelength region to another. Even a simple OPO setup can offer watt-level of continuous-wave power in mid-infrared. There are ongoing challenges with the stability of OPO output frequency and continuous tuning of the wavelength, both of which are important for a light source used in high-resolution molecular spectroscopy. Theory and literature part of this thesis first covers the fundamentals of the theory behind OPO, centering on a continuous-wave single resonant operation. Afterwards, we look into the more well-known features affecting the stability of the OPO, as well as some common schemes used to combat the instabilities. In the experimental part, we measure and attempt to characterize some features of instabilities we have previously noticed that are not readily explained by known instability sources. The OPO's output wavelength occasionally changes in discrete jumps known as mode hops. There appear to be some preferences to the magnitude of these jumps that do not seem to fit in the current understanding of OPO operation. We followed the frequency changes of a typical singly resonant continuous-wave OPO for longer time periods and offered some possible explanations for the observations. We utilize a few methods to increase the number of mode hops to produce meaningful statistical data.

For millennia, phenomena of the magnetosphere have intrigued mankind. Studies of the geomagnetic field were first initiated to locate precious minerals, later on continued for purposes of navigation and in the modern times for scientific interest and protection of modern society. Strong changes in the interplanetary magnetic field and pulses of charged particles originating from the Sun pose serious risks to many cornerstones of our lifestyle, such as the power grid, telecommunication and space safety. Understanding the interaction between the interplanetary magnetic field, solar wind and the geomagnetic field is crucial in building protection systems for these critical technologies. Magnetometers are practically the only instrument to monitor changed in the magnetic environment and thus a key instrument in broadening this understanding. In this thesis I describe two projects: development of a digitization algorithm for old, analog magnetometer data and the design and building process of two small magnetometers: one for ground based measurements and one for space applications. The aim of the digitization project was to digitize a magnetic timeseries produced in 1970s and 1980s. The quality of the dataset is very high, but since the data is saved on photographic film as graphs, proper time series analysis is difficult. During the project, I used a custom-made film scanner and developed a MATLAB program to read out the measured values from the scanned films. The aim of the magnetometer building project was to show that it is possible to build science grade magnetometers from commercial-off-the-shelf (COTS) components, enabling magnetometric campaigns where state of the art instruments would be prohibitively expensive. One magnetometer was built based on the Honeywell HMC5883L sensor, controlled by a Raspberry Pi miniature computer. This magnetometer was placed at the Metsähovi Radio Observatory. Another magnetometer, the CubeMAG, was based on the Honeywell HMC2003 sensor and controlled by an STM32F100 microcontroller. This magnetometer will be one of the science payloads of the ESTCube-2 satellite. The magnetometer placed in Metsähovi showed promising results, recording one strong geomagnetic storm which was also recorded with observatory quality instruments at the Nurmijärvi geophysical observatory. The resolution of the HMC5883L was too low to record most interesting features of the storm, but was high enough to show that the Metsähovi observatory is a suitable place for a more sensitive magnetometer. As of writing this thesis, ESTCube-2 is in development and preparing for launch and scientific results from the CubeMAG are not available. Initial laboratory tests show promising results, with the significantly higher resolution of the HMC2003 compared to the HMC5883L being able to record very small changes in the surrounding magnetic field.

This thesis covers the factorization properties of number fields, and presents the structures necessary for understanding a proof on Iwasawa's theorem. The first three chapters aim to construct a ring of integers for arbitrary number fields, and prove that such a ring exists. We prove that our ring of integers is a Dedekind ring, giving us unique factorization on the set of prime ideals. We prove that there exists an isomorphism between principal and factorial divisors and ideals, define an equivalence relation on the set of all divisors, and show that the equivalence classes form the ideal class group. The class number of a field is defined as the order of the ideal class group. We define ramification of primes, and the invariants related to a prime P called the ramification index, inertia degree and decomposition number. We expand on the Galois theory of finite extensions, by introducing a topology on an infinite algebraic Galois extension, and a Galois correspondence between closed subgroups and intermediate fields. We show how to define the decomposition- and inertia group in the infinite case. The maximal unramified field extension, the Hilbert class field, whose Galois group is isomorphic to the ideal class group, is introduced. We introduce a p-adic metric on the ring of integers with the help of valuations, and construct the p-adic integers as a completion with regards to the metric. We prove some structure results for this ring. The lambda-modules are constructed as a limit of modules over group rings, where the group rings are generated by the p-adic integers, and a suitable multiplicative cyclic group. The final result is a proof of Iwasawa’s theorem as found in Washington, Introduction to Cyclotomic fields. We view the Galois group of the p-adic extension as a lambda-module, and from the structure theorems of lambda-modules, we prove results that carry on to the galois groups of the intermediate fields, culminating in a formula for the exact power of p, that divides the class number of the n-th intermediate field.

The term 'Third World women' has its connotations back in the history reflecting both the juxtaposition of developed and developing world, and the dichotomy based on sex. It is still a widely used concept in current everyday life. The women of developing countries are portrayed under one category as Third World women in news, journalism and textbooks. As a term Third World women is understood in context of certain geographical locations and stagnant representations of people. In core are also their victim roles in relation for example to religion, culture or men. The aim of this master's thesis is to examine representations of the Third World women in Finnish development journal. Temporal changes in representations are discovered by observing the forty-year long publishing history of Kehitys -journal (former Kehitysyhteistyö). The main premise of this thesis is the idea of social constructionism. In social constructionism actions and thoughts are seen creating the social reality and language used both reflecting and creating it. The thesis questions media's representational power to name, illustrate and portray women in developing countries. This is done by utilizing theories of feminism, postcolonialism and development studies. Caroline Moser's and Janet Momsen's listings about the policy approaches on Third World women can be held as the frame work of this thesis. They have categorized global trends in development discourses relating to women. By comparing these approaches, trends in feminist and development theories, with the Finnish development journals, linkages between context and place specific representations of the Third World were found. Even though Finnish trends in Third World women's representations were less varying, still universal relations were able to be discovered. By conducting critical discourse analysis and content analysis of the women related articles in Kehitysyhteistyö and Kehitys -journals during the publications period from 1969 to 2009, it was possible to find five different kinds of discourses: women in development discourse, welfare discourse, efficiency discourse, misery discourse and life story discourse. Within these discourses main changes were in the ways to write and position women. Changes occurred for example in the themes relating to women and in their subjective narration. During forty years, the representations of the Third World women have changed back and forth, but it seems that the current trend in development journalism in Finland is highlighting the subjectivity and expertise of women. Women's own interests and thoughts are getting more exposure and the representational top-down dictation is decreasing while giving the floor to personal depictions.

Halogenated species have a significant impact on atmospheric composition, including catalytic ozone destruction and influence on HOx and NOx cycles. Halogens are also involved in marine and coastal new particle formation, a process that can ultimately affect Earth's radiation balance. However, the exact processes governing halogen chemistry and halogen new particle formation have been puzzling the community for years. One of the major difficulties in understanding these processes has been the lack of techniques able to measure inorganic halogenated radicals and stable species simultaneously both in laboratory studies and in ambient conditions. This is because previous spectroscopic and mass spectrometric methods utilized could only measure one, or a few halogenated species at once, while most of the halogenated species existing in the atmosphere were likely un-measurable. Here we present new chemical ionization (CI) mass spectrometric methods to measure over 20 halogenated species simultaneously at ambient pressure. These species include halogen oxides, halogen acids, nitrogen containing halogen species, halogen radicals and molecular halogens, covering the major categories present in the ambient atmosphere. The methods will further be deployed into field measurements in various locations around the world to better understand the impact of halogenated species to the atmosphere. A recent study revealed homogeneous nucleation processes by (HIO3) (brackets here indicate all the isomers). However, the exact formation mechanism of (HIO3) has not been investigated in laboratory experiments. We deployed the above mentioned new measurements methods to study the formation mechanism of (HIO3) in dedicated flow tube experiments. The results show that OIO and OH radical could form (HIO3) as indicated by previous quantum mechanism calculations. In addition, two novel (HIO3) formation pathways from photo-oxidation of CH2I2 and molecular iodine were suggested. One pathway shows that the homogeneous bimolecular reaction of CH2IOO could form (HIO3), while the other suggests either iodine radical or iodine monoxide could react with ozone and water vapor to form (HIO3). These findings could potentially explain the large amount of (HIO3) observed. Beside from coastal areas, the first ambient data showing the existence of (HIO3) in various locations in the world, including a boreal forest site, a wet land site, Greenland and Antarctica are also presented here. These findings indicate that the (HIO3) might be involved in nucleation processes in locations other than coastal areas. More than (HIO3), sulfuric acid is known for its active role in atmospheric nucleation over different environments. However, the knowledge of its gas phase oxidation processes is not complete. Our laboratory results imply that iodinated species might be able to oxidize SO2 to sulfuric acid through some yet unknown mechanisms. Further studies are needed to understand the exact mechanisms in the oxidation processes and how important this mechanism could be in the ambient atmosphere.