5 resultados para Characteristic Equation

em Helda - Digital Repository of University of Helsinki


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Gentlemen, Lads and the Art of War The Construction of Citizen Soldier- and Professional Soldier Armies into the Miracle of the Winter War During the 1920s and 1930s The Miracle of the Winter War was not a myth - at least according to them, who were making that miracle to happen. This study is not just about the Armed Forces and society, but moreover a study about civil society inside the organization of armed forces. Conscription kept Finnish military organization (and is still keeping) very closely connected with civil society and therefore there is no need to locate the possible critical misunderstandings brought by two different identity-based approaches. The great performance of the Armed Forces during the Second World War was not made of superior art of war. It was not the high level of discipline either. Art of war is basically a (deep level) cultural level equation that has more to do with culturally absorbed schemes of meaning making than rational decision-making. Naturally attrition based approach to effect-making directed the organizational methods in attrition based organisational practices, where there were only minor possibilities to practice any manoeuvre-based organisational behaviour. The practice and method of leadership lent similarly to the attrition-based thinking, which directed the organisational cultural thoughts towards composition that confirmed antagonism between gentlemen and lads . This setting has been absorbed and learned through cultural socialisation and was therefore not a product of the military organisation itself. The Finnish Armed Forces included two different communities (gentlemen and lads) within the same organisation as there were both the official and the unofficial organisations presented. This caused problems as they both made meaning-making processes simultaneously. These organisations had their own overlapping and in most cases also contradictory social meanings. The unofficial organisation has been overshadowed by the vast number of studies concerning the official organisation. The main reason for this systematic neglect is based on the reality of the attitudes and living conditions of the micro-level organisation which produced (perhaps) too realistic and repulsive viewpoints that are presenting a picture of a national level identity process in a way that is separating it from the ideals made to verify the ethos of national values. Complaining, griping, grumbling and moaning are usually situated in a category of abnormal and unwanted behaviour. However, within the context of a citizen soldier army community this was more of a characteristic feature of that organisation (in Finland) and therefore it was crucially important to locate the context of that abnormal behaviour. According to this study, it was not a malicious act but moreover seriously formed efforts in trying to use common sense in the chaos citizen soldiers faced when they were uniformed and placed in an unfamiliar process of disciplinary measures and frictions and competition between different ranks. There is much evidence that reinforces the argument that what seemed to be the most unconventional behaviour was finally the most efficient in a sense of military performance.

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Atmospheric particles affect the radiation balance of the Earth and thus the climate. New particle formation from nucleation has been observed in diverse atmospheric conditions but the actual formation path is still unknown. The prevailing conditions can be exploited to evaluate proposed formation mechanisms. This study aims to improve our understanding of new particle formation from the view of atmospheric conditions. The role of atmospheric conditions on particle formation was studied by atmospheric measurements, theoretical model simulations and simulations based on observations. Two separate column models were further developed for aerosol and chemical simulations. Model simulations allowed us to expand the study from local conditions to varying conditions in the atmospheric boundary layer, while the long-term measurements described especially characteristic mean conditions associated with new particle formation. The observations show statistically significant difference in meteorological and back-ground aerosol conditions between observed event and non-event days. New particle formation above boreal forest is associated with strong convective activity, low humidity and low condensation sink. The probability of a particle formation event is predicted by an equation formulated for upper boundary layer conditions. The model simulations call into question if kinetic sulphuric acid induced nucleation is the primary particle formation mechanism in the presence of organic vapours. Simultaneously the simulations show that ignoring spatial and temporal variation in new particle formation studies may lead to faulty conclusions. On the other hand, the theoretical simulations indicate that short-scale variations in temperature and humidity unlikely have a significant effect on mean binary water sulphuric acid nucleation rate. The study emphasizes the significance of mixing and fluxes in particle formation studies, especially in the atmospheric boundary layer. The further developed models allow extensive aerosol physical and chemical studies in the future.

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An inverse problem for the wave equation is a mathematical formulation of the problem to convert measurements of sound waves to information about the wave speed governing the propagation of the waves. This doctoral thesis extends the theory on the inverse problems for the wave equation in cases with partial measurement data and also considers detection of discontinuous interfaces in the wave speed. A possible application of the theory is obstetric sonography in which ultrasound measurements are transformed into an image of the fetus in its mother's uterus. The wave speed inside the body can not be directly observed but sound waves can be produced outside the body and their echoes from the body can be recorded. The present work contains five research articles. In the first and the fifth articles we show that it is possible to determine the wave speed uniquely by using far apart sound sources and receivers. This extends a previously known result which requires the sound waves to be produced and recorded in the same place. Our result is motivated by a possible application to reflection seismology which seeks to create an image of the Earth s crust from recording of echoes stimulated for example by explosions. For this purpose, the receivers can not typically lie near the powerful sound sources. In the second article we present a sound source that allows us to recover many essential features of the wave speed from the echo produced by the source. Moreover, these features are known to determine the wave speed under certain geometric assumptions. Previously known results permitted the same features to be recovered only by sequential measurement of echoes produced by multiple different sources. The reduced number of measurements could increase the number possible applications of acoustic probing. In the third and fourth articles we develop an acoustic probing method to locate discontinuous interfaces in the wave speed. These interfaces typically correspond to interfaces between different materials and their locations are of interest in many applications. There are many previous approaches to this problem but none of them exploits sound sources varying freely in time. Our use of more variable sources could allow more robust implementation of the probing.