27 resultados para sequential niche technique
em Doria (National Library of Finland DSpace Services) - National Library of Finland, Finland
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Selostus: Mahdollisuus lyhytaikaisen virtsankeruun käyttöön lypsylehmien virtsan pseudouridiinin erityksen määrittämisessä
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Yhteenveto: Käytännöllinen oikeanpuoleinen viiltogastropeksia mahalaukun laajentumisen ja kiertymisen hoitona tai ennaltaehkäisynä
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Image filtering is a highly demanded approach of image enhancement in digital imaging systems design. It is widely used in television and camera design technologies to improve the quality of an output image to avoid various problems such as image blurring problem thatgains importance in design of displays of large sizes and design of digital cameras. This thesis proposes a new image filtering method basedon visual characteristics of human eye such as MTF. In contrast to the traditional filtering methods based on human visual characteristics this thesis takes into account the anisotropy of the human eye vision. The proposed method is based on laboratory measurements of the human eye MTF and takes into account degradation of the image by the latter. This method improves an image in the way it will be degraded by human eye MTF to give perception of the original image quality. This thesis gives a basic understanding of an image filtering approach and the concept of MTF and describes an algorithm to perform an image enhancement based on MTF of human eye. Performed experiments have shown quite good results according to human evaluation. Suggestions to improve the algorithm are also given for the future improvements.
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The objective of this work was to introduce the emerging non-contacting spray coating process and compare it to the existing coating techniques. Particular emphasis was given to the details of the spraying process of paper coating colour and the base paper requirements set by the new coating method. Spraying technology itself is nothing new, but the atomisation process of paper coating colour is quite unknown to the paper industry. The differences between the rheology of painting and coating colours make it very difficult to utilise the existing information from spray painting research. Based on the trials, some basic conclusion can be made:The results of this study suggest that the Brookfield viscosity of spray coating colour should be as low as possible, presently a 50 mPas level is regarded as an optimum. For the paper quality and coater runnability, the solids level should be as high as possible. However, the graininess of coated paper surface and the nozzle wear limits the maximum solids level to 60 % at the moment. Most likelydue to the low solids and low viscosity of the coating colour the low shear Brookfield viscosity correlates very well with the paper and spray fan qualities. High shear viscosity is also important, but yet less significant than the low shear viscosity. Droplet size should be minimized and besides keeping the brrokfield viscosity low that can be helped by using a surfactant or dispersing agent in the coating colour formula. Increasing the spraying pressure in the nozzle can also reduce the droplet size. The small droplet size also improves the coating coverage, since there is hardly any levelling taking place after the impact with the base paper. Because of the lack of shear forces after the application, the pigment particles do not orientate along the paper surface. Therefore the study indicates that based on the present know-how, no quality improvements can be obtained by the use of platy type of pigments. The other disadvantage of them is the rapid deterioration of the nozzle lifetime. Further research in both coating colour rheology and nozzle design may change this in the future, but so far only round shape pigments, like typically calcium carbonate is, can be used with spray coating. The low water retention characteristics of spray coating, enhanced by the low solids and low viscosity, challenge the base paper absorption properties.Filler level has to be low not to increase the number of small pores, which have a great influence on the absorption properties of the base paper. Hydrophobic sizing reduces this absorption and prevents binder migration efficiently. High surface roughness and especially poor formation of the base paper deteriorate thespray coated paper properties. However, pre-calendering of the base paper does not contribute anything to the finished paper quality, at least at the coating colour solids level below 60 %. When targeting a standard offset LWC grade, spraycoating produces similar quality to film coating, but yet blade coating being on a slightly better level. However, because of the savings in both investment and production costs, spray coating may have an excellent future ahead. The porousnature of the spray coated surface offers an optimum substrate for the coldset printing industry to utilise the potential of high quality papers in their business.
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Diplomityössä tarkastellaan palveluoperaattoreiden asemaa Länsi-Euroopan matkapuhelinpalvelumarkkinoilla. Tavoitteena on selvittää, ovatko palveluoperaattorit potentiaalisia asiakkaita tietylle matkapuhelinlisäpalvelujärjestelmien toimittajalle. Lisäksi tavoitteena on rakentaa liiketoimintalaskelmatyökalu, jolla tällaisen järjestelmäinvestoinnin kannattavuus voidaan osoittaa paitsi palveluoperaattorille, myös tämän loppuasiakkaille. Työ aloitetaan matkapuhelinpalvelumarkkinoilla toimivien osapuolten esittelyllä. Eri osapuolten asemaa ja merkitystä matkapuhelinpalvelumarkkinoilla käsitellään. Matkapuhelinpalvelumarkkinoiden kehitystä tarkastellaan uuden teknologian ja erityisesti tulevien palvelujen näkökulmasta. Tarkastelua jatketaan analysoimalla regulaation vaikutusta matkapuhelinpalvelumarkkinoihin. Erityisesti kiinnitetään huomiota regulaation motiiveihin sekä käytännön toteutukseen tietyissä Länsi-Euroopan maissa. Tutkimuksen toteuttamisessa merkittävässä osassa ovat asiantuntijahaastattelut sekä markkina-analyysiraportit.Markkina-analyysissa saatuja tuloksia hyödynnetään liiketoimintalaskelmatyökalun toteutuksessa. Työn tuloksena päädytään myös ratkaisuun palveluoperaattoreiden kiinnostavuudesta asiakassegmenttinä. Tämän lisäksi havaitaan muita potentiaalisia asiakassegmenttejä, joiden tämäntyyppiseen liiketoimintaan soveltuvuutta tutkitaan edelleen.
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Simulation has traditionally been used for analyzing the behavior of complex real world problems. Even though only some features of the problems are considered, simulation time tends to become quite high even for common simulation problems. Parallel and distributed simulation is a viable technique for accelerating the simulations. The success of parallel simulation depends heavily on the combination of the simulation application, algorithm and message population in the simulation is sufficient, no additional delay is caused by this environment. In this thesis a conservative, parallel simulation algorithm is applied to the simulation of a cellular network application in a distributed workstation environment. This thesis presents a distributed simulation environment, Diworse, which is based on the use of networked workstations. The distributed environment is considered especially hard for conservative simulation algorithms due to the high cost of communication. In this thesis, however, the distributed environment is shown to be a viable alternative if the amount of communication is kept reasonable. Novel ideas of multiple message simulation and channel reduction enable efficient use of this environment for the simulation of a cellular network application. The distribution of the simulation is based on a modification of the well known Chandy-Misra deadlock avoidance algorithm with null messages. The basic Chandy Misra algorithm is modified by using the null message cancellation and multiple message simulation techniques. The modifications reduce the amount of null messages and the time required for their execution, thus reducing the simulation time required. The null message cancellation technique reduces the processing time of null messages as the arriving null message cancels other non processed null messages. The multiple message simulation forms groups of messages as it simulates several messages before it releases the new created messages. If the message population in the simulation is suffiecient, no additional delay is caused by this operation A new technique for considering the simulation application is also presented. The performance is improved by establishing a neighborhood for the simulation elements. The neighborhood concept is based on a channel reduction technique, where the properties of the application exclusively determine which connections are necessary when a certain accuracy for simulation results is required. Distributed simulation is also analyzed in order to find out the effect of the different elements in the implemented simulation environment. This analysis is performed by using critical path analysis. Critical path analysis allows determination of a lower bound for the simulation time. In this thesis critical times are computed for sequential and parallel traces. The analysis based on sequential traces reveals the parallel properties of the application whereas the analysis based on parallel traces reveals the properties of the environment and the distribution.
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This work is devoted to the development of numerical method to deal with convection diffusion dominated problem with reaction term, non - stiff chemical reaction and stiff chemical reaction. The technique is based on the unifying Eulerian - Lagrangian schemes (particle transport method) under the framework of operator splitting method. In the computational domain, the particle set is assigned to solve the convection reaction subproblem along the characteristic curves created by convective velocity. At each time step, convection, diffusion and reaction terms are solved separately by assuming that, each phenomenon occurs separately in a sequential fashion. Moreover, adaptivities and projection techniques are used to add particles in the regions of high gradients (steep fronts) and discontinuities and transfer a solution from particle set onto grid point respectively. The numerical results show that, the particle transport method has improved the solutions of CDR problems. Nevertheless, the method is time consumer when compared with other classical technique e.g., method of lines. Apart from this advantage, the particle transport method can be used to simulate problems that involve movingsteep/smooth fronts such as separation of two or more elements in the system.
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Coronary artery disease (CAD) is a chronic process that evolves over decades and may culminate in myocardial infarction (MI). While invasive coronary angiography (ICA) is still considered the gold standard of imaging CAD, non-invasive assessment of both the vascular anatomy and myocardial perfusion has become an intriguing alternative. In particular, computed tomography (CT) and positron emission tomography (PET) form an attractive combination for such studies. Increased radiation dose is, however, a concern. Our aim in the current thesis was to test novel CT and PET techniques alone and in hybrid setting in the detection and assessment of CAD in clinical patients. Along with diagnostic accuracy, methods for the reduction of the radiation dose was an important target. The study investigating the coronary arteries of patients with atrial fibrillation (AF) showed that CAD may be an important etiology of AF because a high prevalence of CAD was demonstrated within AF patients. In patients with suspected CAD, we demonstrated that a sequential, prospectively ECG-triggered CT technique was applicable to nearly 9/10 clinical patients and the radiation dose was over 60% lower than with spiral CT. To detect the functional significance of obstructive CAD, a novel software for perfusion quantification, CarimasTM, showed high reproducibility with 15O-labelled water in PET, supporting feasibility and good clinical accuracy. In a larger cohort of 107 patients with moderate 30-70% pre-test probability of CAD, hybrid PET/CT was shown to be a powerful diagnostic method in the assessment of CAD with diagnostic accuracy comparable to that of invasive angiography and fractional flow reserve (FFR) measurements. A hybrid study may be performed with a reasonable radiation dose in a vast majority of the cases, improving the performance of stand-alone PET and CT angiography, particularly when the absolute quantification of the perfusion is employed. These results can be applied into clinical practice and will be useful for daily clinical diagnosis of CAD.
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With the increase of use of digital media the need for the methods of multimedia protection becomes extremely important. The number of the solutions to the problem from encryption to watermarking is large and is growing every year. In this work digital image watermarking is considered, specifically a novel method of digital watermarking of color and spectral images. An overview of existing methods watermarking of color and grayscale images is given in the paper. Methods using independent component analysis (ICA) for detection and the ones using discrete wavelet transform (DWT) and discrete cosine transform (DCT) are considered in more detail. A novel method of watermarking proposed in this paper allows embedding of a color or spectral watermark image into color or spectral image consequently and successful extraction of the watermark out of the resultant watermarked image. A number of experiments have been performed on the quality of extraction depending on the parameters of the embedding procedure. Another set of experiments included the test of the robustness of the algorithm proposed. Three techniques have been chosen for that purpose: median filter, low-pass filter (LPF) and discrete cosine transform (DCT), which are a part of a widely known StirMark - Image Watermarking Robustness Test. The study shows that the proposed watermarking technique is fragile, i.e. watermark is altered by simple image processing operations. Moreover, we have found that the contents of the image to be watermarked do not affect the quality of the extraction. Mixing coefficients, that determine the amount of the key and watermark image in the result, should not exceed 1% of the original. The algorithm proposed has proven to be successful in the task of watermark embedding and extraction.
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The purpose of this study was to simulate and to optimize integrated gasification for combine cycle (IGCC) for power generation and hydrogen (H2) production by using low grade Thar lignite coal and cotton stalk. Lignite coal is abundant of moisture and ash content, the idea of addition of cotton stalk is to increase the mass of combustible material per mass of feed use for the process, to reduce the consumption of coal and to increase the cotton stalk efficiently for IGCC process. Aspen plus software is used to simulate the process with different mass ratios of coal to cotton stalk and for optimization: process efficiencies, net power generation and H2 production etc. are considered while environmental hazard emissions are optimized to acceptance level. With the addition of cotton stalk in feed, process efficiencies started to decline along with the net power production. But for H2 production, it gave positive result at start but after 40% cotton stalk addition, H2 production also started to decline. It also affects negatively on environmental hazard emissions and mass of emissions/ net power production increases linearly with the addition of cotton stalk in feed mixture. In summation with the addition of cotton stalk, overall affects seemed to negative. But the effect is more negative after 40% cotton stalk addition so it is concluded that to get maximum process efficiencies and high production less amount of cotton stalk addition in feed is preferable and the maximum level of addition is estimated to 40%. Gasification temperature should keep lower around 1140 °C and prefer technique for studied feed in IGCC is fluidized bed (ash in dry form) rather than ash slagging gasifier