A FORMAÇÃO DE LIGAÇÕES DE HIDROGÊNIO π‧‧‧H, F‧‧‧H E C‧‧‧H NOS COMPLEXOS C2H2‧‧‧(HF), C2H2‧‧‧2(HF) E C2H2‧‧‧3(HF)

In this work, a theoretical study on the basis of structural, vibrational, electronic and topological parameters of the C2H2‧‧‧(HF), C2H2‧‧‧2(HF) and C2H2‧‧‧3(HF) complexes concerning the formation of π‧‧‧H, F‧‧‧H and C‧‧‧H hydrogen bonds is presented. The main difference among these complexes is not properly the interaction strength, but the hydrogen bond type whose benchmark is ruled justly by the structure. Meanwhile, the occurrence of π‧‧‧H hydrogen bonds was unveiled in both C2H2‧‧‧(HF) dimer and C2H2‧‧‧3(HF) tetramer, although in latter, this interaction is stronger than C‧‧‧H of the C2H2‧‧‧2(HF) trimer. However, the F‧‧‧H hydrogen bonds within the subunits of hydrofluoric acid are the strongest ones, reaching a partial covalent limit, and thereby contribute decisively to the stabilization of the tetramer structure. In line with this, the largest red-shifts were observed on the hydrofluoric acid trimer of the C2H2‧‧‧3(HF) complex.

Thermal modelling of semiconductor switches in three-level Neutral Point Clamped Medium Voltage DTC-inverter

The aim of this thesis is to investigate the thermal loading of medium voltage three-level NPC inverter’s semiconductor IGCT switches in different operation points. The objective is to reach both a fairly accurate off-line simulation program and also so simple a simulation model that its implementation into an embedded system could be reasonable in practice and a real time use should become feasible. Active loading limitation of the inverter can be realized with a thermal model which is practical in a real time use. Determining of the component heating has been divided into two parts; defining of component losses and establishing the structure of a thermal network. Basics of both parts are clarified. The simulation environment is Matlab-Simulink. Two different models are constructed – a more accurate one and a simplified one. Potential simplifications are clarified with the help of the first one. Simplifications are included in the latter model and the functionalities of both models are compared. When increasing the calculation time step a decreased number of considered components and time constants of the thermal network can be used in the simplified model. Heating of a switching component is dependent on its topological position and inverter’s operation point. The output frequency of the converter defines mainly which one of the switching components is – because of its losses and heating – the performance limiting component of the converter. Comparison of results given by different thermal models demonstrates that with larger time steps, describing of fast occurring switching losses becomes difficult. Generally articles and papers dealing with this subject are written for two-level inverters. Also inverters which apply direct torque control (DTC) are investigated rarely from the heating point of view. Hence, this thesis completes the former material.

Evaluation of group electronegativities and hardness (softness) of group 14 elements and containing functional groups through density functional theory and correlation with NMR spectra data

Quantum Chemical calculations for group 14 elements of Periodic Table (C, Si, Ge, Sn, Pb) and their functional groups have been carried out using Density Functional Theory (DFT) based reactivity descriptors such as group electronegativities, hardness and softness. DFT calculations were performed for a large series of tetracoordinated Sn compounds of the CH3SnRR'X type, where X is a halogen and R and R' are alkyl, halogenated alkyl, alkoxy, or alkyl thio groups. The results were interpreted in terms of calculated electronegativity and hardness of the SnRR'X groups, applying a methodology previously developed by Geerlings and coworkers (J. Phys. Chem. 1993, 97, 1826). These calculations allowed to see the regularities concerning the influence of the nature of organic groups RR' and inorganic group X on electronegativities and hardness of the SnRR'X groups; in this case, it was found a very good correlation between the electronegativity of the fragment and experimental 119Sn chemical shifts, a property that sensitively reflects the change in the valence electronic structure of molecules. This work was complemented with the study of some compounds of the EX and ER types, where E= C, Si, Ge, Sn and R= CH3, H, which was performed to study the influence that the central atom has on the electronegativity and hardness of molecules, or whether these properties are mainly affected for the type of ligand bound to the central atom. All these calculations were performed using the B3PW91 functional together with the 6-311++G** basis set level for H, C, Si, Ge, F, Cl and Br atoms and the 3-21G for Sn and I atoms.

On Undecidable Dynamical Properties of Reversible One-Dimensional Cellular Automata

Cellular automata are models for massively parallel computation. A cellular automaton consists of cells which are arranged in some kind of regular lattice and a local update rule which updates the state of each cell according to the states of the cell's neighbors on each step of the computation. This work focuses on reversible one-dimensional cellular automata in which the cells are arranged in a two-way in_nite line and the computation is reversible, that is, the previous states of the cells can be derived from the current ones. In this work it is shown that several properties of reversible one-dimensional cellular automata are algorithmically undecidable, that is, there exists no algorithm that would tell whether a given cellular automaton has the property or not. It is shown that the tiling problem of Wang tiles remains undecidable even in some very restricted special cases. It follows that it is undecidable whether some given states will always appear in computations by the given cellular automaton. It also follows that a weaker form of expansivity, which is a concept of dynamical systems, is an undecidable property for reversible one-dimensional cellular automata. It is shown that several properties of dynamical systems are undecidable for reversible one-dimensional cellular automata. It shown that sensitivity to initial conditions and topological mixing are undecidable properties. Furthermore, non-sensitive and mixing cellular automata are recursively inseparable. It follows that also chaotic behavior is an undecidable property for reversible one-dimensional cellular automata.

Pencil grip : a descriptive model and four empirical studies

Previous studies on pencil grip have typically dealt with the developmental aspects in young children while handwriting research is mainly concerned with speed and legibility. Studies linking these areas are few. Evaluation of the existing pencil grip studies is hampered by methodological inconsistencies. The operational definitions of pencil grip arerational but tend to be oversimplified while detailed descriptors tend to be impractical due to their multiplicity. The present study introduces a descriptive two-dimensional model for the categorisation of pencil grip suitable for research applications in a classroom setting. The model is used in four empirical studies of children during the first six years of writing instruction. Study 1 describes the pencil grips observed in a large group of pupils in Finland (n = 504). The results indicate that in Finland the majority of grips resemble the traditional dynamic tripod grip. Significant genderrelated differences in pencil grip were observed. Study 2 is a longitudinal exploration of grip stability vs. change (n = 117). Both expected and unexpected changes were observed in about 25 per cent of the children's grips over four years. A new finding emerged using the present model for categorisation: whereas pencil grips would change, either in terms of ease of grip manipulation or grip configuration, no instances were found where a grip would have changed concurrently on both dimensions. Study 3 is a cross-cultural comparison of grips observed in Finland and the USA (n = 793). The distribution of the pencil grips observed in the American pupils was significantly different from those found in Finland. The cross-cultural disparity is most likely related to the differences in the onset of writing instruction. The differences between the boys' and girls' grips in the American group were non-significant.An implication of Studies 2 and 3 is that the initial pencil grip is of foremost importance since pencil grips are largely stable over time. Study 4 connects the pencil grips to assessment of the mechanics of writing (n = 61). It seems that certain previously not recommended pencil grips might nevertheless be includedamong those accepted since they did not appear to hamper either fluency or legibility.

Lärande som text : en dramapedagogiskt förankrad läsning av det kroppsliga, rumsliga och retoriska i kunskapsbildande processer

My presupposition, that learning at some level deals with life praxis, is expressed in four metaphors: space, time, fable and figure. Relations between learning,knowledge building and meaning making are linked to the concept of personal knowledge. I present a two part study of learning as text in a drama pedagogical rooted reading where learning is framed as the ongoing event, and knowledge, as the product of previous processes, is framed as culturally formed utterances. A frame analysis model is constructed as a topological guide for relations between the two concepts learning and knowledge. It visualises an aesthetic understanding, rooted in drama pedagogical comprehension. Insight and perception are linked in an inner relationship that is neither external nor identical. This understanding expresses the movement "in between" connecting asymmetrical and nonlinear features of human endeavour and societal issues. The performability of bodily and oral participation in the learning event in a socio-cultural setting is analysed as a dialogised text. In an ethnographical case study I have gathered material with an interest for the particular. The empirical material is based on three problem based learning situations in a Polytechnic setting. The act of transformation in the polyphony of the event is considered as a turning point in the narrative employment. Negotiation and figuration in the situation form patterns of the space for improvisation (flow) and tensions at the boundaries (thresholds) which imply the logical structure of transformation. Learning as a dialogised text of "yes" and "no", of structure and play for the improvised, interrelate in that movement. It is related to both the syntagmic and the paradigmatic forms of thinking. In the philosophical study, forms of understanding are linked to the logical structure of transformation as a cultural issue. The classical rhetorical concepts of Logos, Pathos, Ethos and Mythos are connected to the multidimensional rationality of the human being. In the Aristotelian form of knowledge, phronesis,a logic structure of inquiry is recognised. The shifting of perspectives between approaches, the construction of knowledge as context and the human project of meaning making as a subtext, illuminates multiple layers of the learning text. In an argumentation that post-modern apprehension of knowledge, emphasising contextual and situational values, has an empowering impact on learning, I find pedagogical benefits. The dialogical perspective has opened lenses that manage to hold in aesthetic doubling the individual action of inquiry and the stage with its cultural tools in a three dimensional reading.

GIS assessing traditional and modern agricultural land use/land cover change. A case study 1959-2005: Rekijoki, Somero, SW-Finland

Finland’s rural landscape has gone through remarkable changes from the 1950’s, due to agricultural developments. Changed farming practices have influenced especially traditional landscape management, and modifications in the arable land structure and grasslands transitions are notable. The review of the previous studies reveal the importance of the rural landscape composition and structure to species and landscape diversity, whereas including the relevance in presence of the open ditches, size of the field and meadow patches, topology of the natural and agricultural landscape. This land-change study includes applying remote sensed data from two time series and empirical geospatial analysis in Geographic Information Systems (GIS). The aims of this retrospective research is to detect agricultural landscape use and land cover change (LULCC) dynamics and discuss the consequences of agricultural intensification to landscape structure covering from the aspects of landscape ecology. Measurements of LULC are derived directly from pre-processed aerial images by a variety of analytical procedures, including statistical methods and image interpretation. The methodological challenges are confronted in the process of landscape classification and combining change detection approaches with landscape indices. Particular importance is paid on detecting agricultural landscape features at a small scale, demanding comprehensive understanding of such agroecosystems. Topological properties of the classified arable land and valley are determined in order to provide insight and emphasize the aspect the field edges in the agricultural landscape as important habitat. Change detection dynamics are presented with change matrix and additional calculations of gain, loss, swap, net change, change rate and tendencies are made. Transition’s possibility is computed following Markov’s probability model and presented with matrix, as well. Thesis’s spatial aspect is revealed with illustrative maps providing knowledge of location of the classified landscape categories and location of the dynamics of the changes occurred. It was assured that in Rekijoki valley’s landscape, remarkable changes in landscape has occurred. Landscape diversity has been strongly influenced by modern agricultural landscape change, as NP of open ditches has decreased and the MPS of the arable plot has decreased. Overall change in the diversity of the landscape is determined with the decrease of SHDI. Valley landscape considered as traditional land use area has experienced major transitional changes, as meadows class has lost almost one third of the area due to afforestation. Also, remarkable transitions have occurred from forest to meadow and arable land to built area. Boundaries measurement between modern and traditional landscape has indicated noticeable proportional increase in arable land-forest edge type and decrease in arable land-meadow edge type. Probability calculations predict higher future changes for traditional landscape, but also for arable land turning into built area.

Vegetative and reproductive development of Costa Rican weedy rice compared with commercial rice (Oryza sativa)

The variability in the chronology of the vegetative and reproductive development of weedy rice complex has been little studied. However, a field trial was established to study the timing of growth stages of sixteen weedy rice morphotypes and five rice varieties of Costa Rica. Weedy rice presented a wide range of variation for all descriptors among and within morphotypes. Weedy rice was taller than the rice varieties during vegetative phase and showed a growth increase of 14-23 cm every two weeks. Six morphotypes emerged earlier than commercial rice varieties, but no differences where found between samples for the time required for starting tillering. Early emergence of weedy rice morphotypes was not associated with early flowering, thus no correlation was detected between the vegetative and reproductive phases. All weedy rice morphotypes reached anthesis and maturity earlier than the rice varieties. Nevertheless, varieties Setesa-9 and CR-5272 overlapped anthesis with eleven morphotypes and variety CR-4338 overlapped flowering with eight weedy rice morphotypes. In contrast, none of the morphotypes overlapped anthesis with varieties CR-1821 and CR-1113. The results obtained showed the competitive capacity of weedy rice and provided valuable information about flowering overlap between weedy rice morphotypes and rice varieties which will be useful in the design of gene flow studies among them.

Subshifts with Simple Cellular Automata

A subshift is a set of in nite one- or two-way sequences over a xed nite set, de ned by a set of forbidden patterns. In this thesis, we study subshifts in the topological setting, where the natural morphisms between them are ones de ned by a (spatially uniform) local rule. Endomorphisms of subshifts are called cellular automata, and we call the set of cellular automata on a subshift its endomorphism monoid. It is known that the set of all sequences (the full shift) allows cellular automata with complex dynamical and computational properties. We are interested in subshifts that do not support such cellular automata. In particular, we study countable subshifts, minimal subshifts and subshifts with additional universal algebraic structure that cellular automata need to respect, and investigate certain criteria of `simplicity' of the endomorphism monoid, for each of them. In the case of countable subshifts, we concentrate on countable so c shifts, that is, countable subshifts de ned by a nite state automaton. We develop some general tools for studying cellular automata on such subshifts, and show that nilpotency and periodicity of cellular automata are decidable properties, and positive expansivity is impossible. Nevertheless, we also prove various undecidability results, by simulating counter machines with cellular automata. We prove that minimal subshifts generated by primitive Pisot substitutions only support virtually cyclic automorphism groups, and give an example of a Toeplitz subshift whose automorphism group is not nitely generated. In the algebraic setting, we study the centralizers of CA, and group and lattice homomorphic CA. In particular, we obtain results about centralizers of symbol permutations and bipermutive CA, and their connections with group structures.

Concanavalin A-reactive nuclear matrix glycoprotein

The binding capacity of concanavalin A (Con A) to condensed euchromatin and heterochromatin was investigated in chicken erythrocyte nuclei (CEN), mouse liver cells, Zea mays mays meristematic cells and Drosophila melanogaster polytene chromosomes after 4 N HCl hydrolysis to determine whether binding was preferentially occurring in bands and heterochromatin. Dry mass (DM) variation was investigated in CEN by interference microscopy. Feulgen and Con A reactions were employed for all materials to correlate the loci of the two reactions. Quantifications and topological verifications were carried out by video image analysis (high performance cytometry). It was observed that 4 N HCl hydrolysis caused an important DM loss in CEN leaving a level corresponding to the average DNA DM content. In this material, Con A binding was restricted to the nuclear envelope, which reinforces the idea of the absence of a nuclear matrix in these cells. The other cell types exhibited a correspondence of Feulgen-positive and Con A-reactive areas. The Con A reaction was highly positive in the condensed chromatin areas and heterochromatin. This fact led us to speculate that Con A-positive proteins may play a role in the chromatin condensation mechanism, endowing this structure with physico-chemical stability towards acid hydrolysis and contributing to its rheological properties.

Forecasting financial weather - can we foresee market sentiment? Spectrum of stock price behavior - NYSE case study

The desire to create a statistical or mathematical model, which would allow predicting the future changes in stock prices, was born many years ago. Economists and mathematicians are trying to solve this task by applying statistical analysis and physical laws, but there are still no satisfactory results. The main reason for this is that a stock exchange is a non-stationary, unstable and complex system, which is influenced by many factors. In this thesis the New York Stock Exchange was considered as the system to be explored. A topological analysis, basic statistical tools and singular value decomposition were conducted for understanding the behavior of the market. Two methods for normalization of initial daily closure prices by Dow Jones and S&P500 were introduced and applied for further analysis. As a result, some unexpected features were identified, such as a shape of distribution of correlation matrix, a bulk of which is shifted to the right hand side with respect to zero. Also non-ergodicity of NYSE was confirmed graphically. It was shown, that singular vectors differ from each other by a constant factor. There are for certain results no clear conclusions from this work, but it creates a good basis for the further analysis of market topology.

Local Binary Patterns in Focal-Plane Processing. Analysis and Applications

Feature extraction is the part of pattern recognition, where the sensor data is transformed into a more suitable form for the machine to interpret. The purpose of this step is also to reduce the amount of information passed to the next stages of the system, and to preserve the essential information in the view of discriminating the data into different classes. For instance, in the case of image analysis the actual image intensities are vulnerable to various environmental effects, such as lighting changes and the feature extraction can be used as means for detecting features, which are invariant to certain types of illumination changes. Finally, classification tries to make decisions based on the previously transformed data. The main focus of this thesis is on developing new methods for the embedded feature extraction based on local non-parametric image descriptors. Also, feature analysis is carried out for the selected image features. Low-level Local Binary Pattern (LBP) based features are in a main role in the analysis. In the embedded domain, the pattern recognition system must usually meet strict performance constraints, such as high speed, compact size and low power consumption. The characteristics of the final system can be seen as a trade-off between these metrics, which is largely affected by the decisions made during the implementation phase. The implementation alternatives of the LBP based feature extraction are explored in the embedded domain in the context of focal-plane vision processors. In particular, the thesis demonstrates the LBP extraction with MIPA4k massively parallel focal-plane processor IC. Also higher level processing is incorporated to this framework, by means of a framework for implementing a single chip face recognition system. Furthermore, a new method for determining optical flow based on LBPs, designed in particular to the embedded domain is presented. Inspired by some of the principles observed through the feature analysis of the Local Binary Patterns, an extension to the well known non-parametric rank transform is proposed, and its performance is evaluated in face recognition experiments with a standard dataset. Finally, an a priori model where the LBPs are seen as combinations of n-tuples is also presented

Estimation procedures affect the center of pressure frequency analysis

Even though frequency analysis of body sway is widely applied in clinical studies, the lack of standardized procedures concerning power spectrum estimation may provide unreliable descriptors. Stabilometric tests were applied to 35 subjects (20-51 years, 54-95 kg, 1.6-1.9 m) and the power spectral density function was estimated for the anterior-posterior center of pressure time series. The median frequency was compared between power spectra estimated according to signal partitioning, sampling rate, test duration, and detrending methods. The median frequency reliability for different test durations was assessed using the intraclass correlation coefficient. When increasing number of segments, shortening test duration or applying linear detrending, the median frequency values increased significantly up to 137%. Even the shortest test duration provided reliable estimates as observed with the intraclass coefficient (0.74-0.89 confidence interval for a single 20-s test). Clinical assessment of balance may benefit from a standardized protocol for center of pressure spectral analysis that provides an adequate relationship between resolution and variance. An algorithm to estimate center of pressure power density spectrum is also proposed.

Transduction motif analysis of gastric cancer based on a human signaling network

To investigate signal regulation models of gastric cancer, databases and literature were used to construct the signaling network in humans. Topological characteristics of the network were analyzed by CytoScape. After marking gastric cancer-related genes extracted from the CancerResource, GeneRIF, and COSMIC databases, the FANMOD software was used for the mining of gastric cancer-related motifs in a network with three vertices. The significant motif difference method was adopted to identify significantly different motifs in the normal and cancer states. Finally, we conducted a series of analyses of the significantly different motifs, including gene ontology, function annotation of genes, and model classification. A human signaling network was constructed, with 1643 nodes and 5089 regulating interactions. The network was configured to have the characteristics of other biological networks. There were 57,942 motifs marked with gastric cancer-related genes out of a total of 69,492 motifs, and 264 motifs were selected as significantly different motifs by calculating the significant motif difference (SMD) scores. Genes in significantly different motifs were mainly enriched in functions associated with cancer genesis, such as regulation of cell death, amino acid phosphorylation of proteins, and intracellular signaling cascades. The top five significantly different motifs were mainly cascade and positive feedback types. Almost all genes in the five motifs were cancer related, including EPOR,MAPK14, BCL2L1, KRT18,PTPN6, CASP3, TGFBR2,AR, and CASP7. The development of cancer might be curbed by inhibiting signal transductions upstream and downstream of the selected motifs.

Sensory profile of Italian salami with coriander (Coriandrum sativum L.) essential oil

The descriptive terminology and sensory prolife of four samples of Italian salami were determined using a methodology based on the Quantitative Descriptive Analysis (QDA). A sensory panel consensually defined sensory descriptors, their respective reference materials, and the descriptive evaluation ballot. Twelve individuals were selected as judges and properly trained. They used the following criteria: discriminating power, reproducibility, and individual consensus. Twelve descriptors were determined showing similarities and differences among the Italian salami samples. Each descriptor was evaluated using a 10 cm non-structured scale. The data were analyzed by ANOVA, Tukey test, and the Principal Component Analysis (PCA). The salami with coriander essential oil (T3) had lower rancid taste and rancid odor, whereas the control (T1) showed high values of these sensory attributes. Regarding brightness, T4 showed the best result. For the other attributes, T1, T2, T3, and T4 were similar.