This paper introduces a high-gain, low-noise band-pass filter system for detection/amplification of small signals. In addition, related theory and methodology are described for a specific design implementation. Simulation and experimental results are presented and discussed. The purpose of the implemented design was to construct a band-pass filter system with 102 dB gain and with an output noise level of less than 0.8V. The design of the high-gain band-pass filter system was achieved mainly with the help of Filter Pro, LTSpice IV, and Multisim 12. The thesis provides important support for the project Marker Locator and constitutes a valuable reference for future active filter system design and small signal detection/amplification. / Marker Locator

Because the volume of flow through an inlet is proportional to the tidal range and the area of the tidal basin, Texas tidal inlets have some of the largest tidal basins relative to their entrance area of any inlet. Matagorda Bay at Pass Cavallo has an area of about 200 square miles, but only a mean diurnal tidal range of about 1.1 feet. From tide gage records the most important events modifying tidal currents in Pass Cavallo are the numerous wind tides each year that occur most frequently during the cooler months, November through May. Wind tides are most noticeable in Matagorda Bay because the astronomical tidal range is small, the fetch long (10-20 miles) and the depth only about 12 feet. Hurricanes and river floods that would raise water levels in Matagorda Bay by even 0.5 foot occur too infrequently to affect equilibrium conditions in the inlet. Pass Cavallo has passed through three time periods since 1856: 1856-1930, 1930-1965, and post 1965. Each time period was characterized by a different, and subsequently smaller tidal discharge, cross-sectional area and tidal channel length. The tidal discharge decreased between 1929 and 1935 when the Colorado River delta cut off part of east Matagorda Bay to reduce the tidal area of Matagorda Bay, and in 1965, the Matagorda Ship Channel was dredged across Matagorda Peninsula to reduce the volume of water passing through Pass Cavallo. Other features that changed with decreasing discharge, but remained stable during each time period, were the channel pattern, and location and shape of the Gulf bar and Pelican Island. During all three periods Pass Cavallo maintained stable cross-sectional shape, and tidal flow by-passing characteristics, except during the post 1965 when neither tidal flow by-passing nor bar by-passing were dominant. Since 1856 Pass Cavallo has remained geographically stable relative to its width. The axial trough has migrated southwestward about 1000 feet during the past 100 years--or about 1/9th the distance between Matagorda Peninsula and Matagorda Island. Shorelines adjacent to the inlet also have tended to move southwestward, but at a faster rate than the axial trough. Along the western side of the pass, shoreline erosion is related to jetties interrupting sediment transport southward from the western shoreline of Matagorda Bay, and to storms eroding the constructional beach extending northward from Matagorda Island. The modern flood delta at Pass Cavallo consists of a large, sandy platform, that is lobate into Espiritu Santo Bay with salt marsh, storm-tidal flats and tidal channels. The flood delta is located to the side of the channel pattern of Pass Cavallo, and appears to be active only during the high tides of hurricanes, tropical storms and "northers". There are three informal physiographic provinces on the flood delta, each one reflecting a different sediment supply and energy regime inherent in each bay and in the Gulf. 1) The Gulf of Mexico Province has the largest and best-developed intertidal beaches, surge channels, storm-tidal flats and mounds of all three provinces. Sand is the dominant sediment. 2) Matagorda Bay Province includes large marsh islands and tidal channels with fewer large vegetated mounds. Shell is very abundant in mounds, and a storm-tidal flats contain more mud and encroaching salt marsh than in the Gulf province. 3) Espiritu Santo Bay Province is composed mostly of sandy mud or muddy sand sediment, with the exception of erosional shell beaches that face a north or south fetch of 1 to 2 miles. This is the richest area biologically, consisting mostly of salt marsh and grassflats. / text

No description available.

This research study deals mainly with the influence of the medium of instruction on throughput at the Vaal University of Technology. The underlying hypothesis driving this research, is that learners at the Vaal University of Technology will tend to underachieve during their period of study, largely because the medium of instruction and assessment is not their first language, but a second or even a third language. The assertion is that learners on tertiary level can only perform academically well if they have gained a certain level of competency in their mother tongue, to ease the difficult process of acquiring the second language English, which is the main medium of instruction at the VUT. For most human beings language is the medium through which knowledge is transferred or negotiated. The success of this interaction is determined by the effectiveness of communication. Thus it would be fair to say, that if the means of communication is inappropriate, there will be little or no language transfer. Further, it seems logical that before any other considerations are made with regard to teaching and learning, the instrument which enables this interaction should first be in place. The research aims are: to determine the influence of a second language as medium of instruction on academic performance, to establish the nature of the support system which might facilitate the advancement of learners not prepared for the academic demands of university, to determine what can be done to address the problem and provide possible recommendations for improved academic performance. In order to attain the abovementioned research aims, a literature review and an empirical investigation were undertaken. The literature study discussed the role which the medium of instruction has played in the history of South African Education. The South African Language Policy, before and after 1994, was then reviewed. Parent and learner choice in respect of the choice of medium of instruction was then considered. The findings of the empirical study have shown that the medium of instruction has a remarkable influence on learners' proficiency and eventual performance in their content subjects. The empirical research was conducted by using a questionnaire in order to obtain data on relevant variables as indicated by the literature study, as well as identify barriers perceived by students that hamper their academic progress. Descriptive statistics, such as frequencies, were used to summarize the data. Marks from the compulsory language test at the institution were also taken into account in order to establish learners' English language proficiency. This data, together with students' marks, were interpreted in the empirical analysis. The target population for this study consisted of L1 and L2 students who registered in 2004 and will have completed their studies in 2006, as well as students having completed in 2007. The population consisted of both female and male students from the Faculty of Visual Arts and Design. In the last chapter, Chapter 6, conclusions from the literature review and empirical investigation were drawn. Recommendations for further research were provided which stressed the need for developing an appropriate training course for L2MI (Second Language Medium of Instruction) content subject teachers. Effective training in L2MI is one of the most important factors in improving the level of academic literacy in South African learners. / Thesis (M.Ed.)--North-West University, Vaal Triangle Campus, 2009.

This research study deals mainly with the influence of the medium of instruction on throughput at the Vaal University of Technology. The underlying hypothesis driving this research, is that learners at the Vaal University of Technology will tend to underachieve during their period of study, largely because the medium of instruction and assessment is not their first language, but a second or even a third language. The assertion is that learners on tertiary level can only perform academically well if they have gained a certain level of competency in their mother tongue, to ease the difficult process of acquiring the second language English, which is the main medium of instruction at the VUT. For most human beings language is the medium through which knowledge is transferred or negotiated. The success of this interaction is determined by the effectiveness of communication. Thus it would be fair to say, that if the means of communication is inappropriate, there will be little or no language transfer. Further, it seems logical that before any other considerations are made with regard to teaching and learning, the instrument which enables this interaction should first be in place. The research aims are: to determine the influence of a second language as medium of instruction on academic performance, to establish the nature of the support system which might facilitate the advancement of learners not prepared for the academic demands of university, to determine what can be done to address the problem and provide possible recommendations for improved academic performance. In order to attain the abovementioned research aims, a literature review and an empirical investigation were undertaken. The literature study discussed the role which the medium of instruction has played in the history of South African Education. The South African Language Policy, before and after 1994, was then reviewed. Parent and learner choice in respect of the choice of medium of instruction was then considered. The findings of the empirical study have shown that the medium of instruction has a remarkable influence on learners' proficiency and eventual performance in their content subjects. The empirical research was conducted by using a questionnaire in order to obtain data on relevant variables as indicated by the literature study, as well as identify barriers perceived by students that hamper their academic progress. Descriptive statistics, such as frequencies, were used to summarize the data. Marks from the compulsory language test at the institution were also taken into account in order to establish learners' English language proficiency. This data, together with students' marks, were interpreted in the empirical analysis. The target population for this study consisted of L1 and L2 students who registered in 2004 and will have completed their studies in 2006, as well as students having completed in 2007. The population consisted of both female and male students from the Faculty of Visual Arts and Design. In the last chapter, Chapter 6, conclusions from the literature review and empirical investigation were drawn. Recommendations for further research were provided which stressed the need for developing an appropriate training course for L2MI (Second Language Medium of Instruction) content subject teachers. Effective training in L2MI is one of the most important factors in improving the level of academic literacy in South African learners. / Thesis (M.Ed.)--North-West University, Vaal Triangle Campus, 2009.

No description available.

This study focuses on large vocabulary Turkish continuous speech recognition. Continuous speech recognition for Turkish cannot be performed accurately because of the agglutinative nature of the language. The agglutinative nature decreases the performance of the classical language models that are used in the area. In this thesis firstly, acoustic models using different parameters are constructed and tested. Then, three types of n-gram language models are built. These involve class-based models, stem-based models, and stem-end-based models. Two pass recognition is performed using the Hidden Markov Modeling Toolkit (HTK) for testing the system first with the bigram models and then with the trigram models. At the end of the study, it is found that trigram models over stems and endings give better results, since their coverage of the vocabulary is better.

A large theoretical and empirical literature has studied the response in prices to changes in demands and costs. Three of the essays in this thesis are empirical studies of price-setting. The most important reason for studying the properties of price adjustments is the possible link between pricing and the business cycle. One family of models deals with price rigidities. If prices adjust slowly to changes in costs or demand, it will magnify fluctuations in output. A second family of models examines price changes due to changes in intensity of competition. Many of these models build on the idea that changes in demand affect the possibility of maintaining implicit collusion. Cyclical changes in the intensity of competition may cause a cyclical pricing pattern that magnifies fluctuations in output. Another line of research models the effects of liquidity constraints on the business cycle. One possible effect is that prices in markets where consumers have switching costs may increase, if the firms are hit by increased liquidity constraints. As increased liquidity constraints are common in recessions, prices will get a counter-cyclical tendency, which magnifies fluctuations in output. Another reason for studying price-setting patterns is that they can give an indication of the form of interaction between competing firms, which are of importance for competition policy. The fourth essay models sex discrimination formally. It shows that it is possible that sex discrimination in the labor market might be due to self-fulfilling sex stereotypes on the distribution of time out for child care between men and women. Both an even and an uneven distribution of time out for child care are possible equilibria in the model. The four essays can be read separatelyEssay 1 Price Responses to Seasonal Demand Changes in the Swedish Gasoline MarketA common idea in a number of papers on cyclical pricing is that implicit price collusion may be affected by changes in demand. In these models, tacit collusion is modeled as a game where agents balance gains from deviating from the collusive price, thereby gaining a short-run profit, against the gains from maintaining collusion in future periods. If demand fluctuates, the gains from deviating is high in periods of high demand; collusion may still be sustainable, however, if the collusive price is allowed to vary with demand. A lower price in high demand states reduces the gains from deviating, since it reduces the gain from each unit sold in these demand states. Hence, in order to equalize the profit from deviating and the profit from sticking to the implicit agreement, the price must move in the opposite direction to demand. Changes in demand can, naturally, be correlated with other factors affecting the price, such as cost changes. Thus, prices do not necessarily fall when demand increases in the data. According to the theory the, however, increase in demand should add a tendency to lower prices in order to make implicit collusion sustainable. The basic idea that changes in demand should affect prices if firms are engaged in implicit collusion has been employed in a number of papers, with different models for different assumptions on the pattern of demand changes. The demand for gasoline in Sweden follows a seasonal cycle, with demand being 42 percent higher in July than in January. Haltiwanger and Harrington provide a theory for implicit collusion over deterministic cycles, such as the seasonal cycle. Borenstein and Shepard (1996) tested Haltiwanger and Harrington’s model on the American gasoline retail market and found support for the theory. In this essay the model is tested for Swedish data, but no support for this theory is found. It is also investigated whether the effects on margins of the demand fluctuations induced by tax increases are compatible with theories of implicit collusion, but this is found not to be the case.Essay 2 Price Adjustments by a Gasoline Retail ChainEssay 2 is joint with Marcus Asplund and Richard Friberg. Stickiness of prices is an important building block in many business cycle models. This has spurred an empirical literature on price adjustments. Different types of price rigidities have different policy implications. Price setting can be state dependent, e.g. prices are adjusted when costs have changed by at least some minimal amount since the last price adjustment, or time-dependent e.g. adjusted once a week or once a year. Another issue is whether prices are equally rigid downwards as upwards. The second essay examines price responses in the Swedish gasoline retail market to changes in the Rotterdam spot price of gasoline, exchange rates and taxes. The main results are that cost changes are not fully passed through in the short run, but gradually moves towards the long-run equilibrium. Prices are stickier downwards than upwards. There is a minimum absolute size of price changes. Only very limited evidence of time-dependent price setting is found.Essay 3 Prices, Margins and Liquidity Constraints: Swedish Newspapers 1990-1996Essay 3 is written with Marcus Asplund and Niklas Strand. Chevalier and Scharfstein (1996) provide a model where consumer switching costs in combination with liquidity constraints give rise to a counter-cyclical tendency in prices. Customer stocks can be viewed as an investment, when consumers have switching costs when changing suppliers. Firms can exploit captured customers by setting a high price to raise short-run profits. However, a high price will induce consumers to search for alternatives, and customers once lost are costly to win back. Liquidity constraints, for instance in recessions, may force firms to sacrifice long-run profits for short-run gains. In this case, firms may have to cut back on investments in customer stocks by raising prices. Using firm level data from the Swedish daily newspaper industry, we test the effects of liquidity constraints on prices in markets with consumer switching costs. The newspaper industry is of particular interest, since firms set prices in two markets, the subscription market, where switching costs are high, and the advertising market, where switching costs are low. With accounting data from newspaper firms we can, by solvency, broadly categorize them as being more or less liquidity constrained. When Sweden enters a recession at the beginning of the nineties, we find a relative increase in subscription prices and margins for liquidity constrained firms. This is not the case for advertising prices, however. The results support the theory.Essay 4 Statistical Discrimination and Sex Stereotypes in the Labor MarketTime out for child care is unevenly distributed between the sexes. Parental leave benefits are usually exclusively given to the mother or distributed to both parents according to their choice. In Sweden, one month is reserved for each parent, however. One reason for this is to give the child better contact with both parents, but increased equality between the sexes in the labor market has also been put forward as an argument. This argument implicitly rests on the idea that sex stereotypes create sex discrimination, and that sex discrimination affects the distribution of time out for child care between the sexes. Essay 4 investigates if the uneven distribution of time out for child care can be explained by self-fulfilling sex stereotypes. It provides a model of distribution of time out for child care based on statistical discrimination and human capital investments. The model has three equilibria. In one equilibrium, time out for child care is evenly distributed between the sexes. In the second equilibrium, there is full specialization. The third equilibrium is an intermediate case, where time out for child care is unevenly distributed without full specialization There are no differences in ability or variance of ability between the sexes, the only differences between the equilibria are the self-fulfilling expectations of firms and workers. / Diss. (sammanfattning) Stockholm : Handelshögsk., 2001

Στην παρούσα διπλωματική εργασία ασχοληθήκαμε με την εύρεση του καρδιακού παλμού ενός ατόμου με τεχνικές ψηφιακής επεξεργασίας εικόνας στο κοντινό και στο μέσο υπέρυθρο φάσμα. Χρησιμοποιήσαμε μια σειρά από διόδους εκπομπής στο υπέρυθρο φάσμα και μια βιντεοκάμερα με την οποία πήραμε τα προς εξέταση δεδομένα. Στηριζόμαστε στην ιδιότητας της αιμοσφαιρίνης να απορροφά το υπέρυθρο φως ορισμένου μήκους κύματος. Επεξεργαζόμενοι το οπτικό υλικό που προκύπτει από τις μετρήσεις μας με κατάλληλες μεθόδους μπορούμε να πλησιάσουμε στην εύρεση του καρδιακού ρυθμού, μελετώντας τα βιολογικά σήματα και ευρίσκοντας μεθόδους βελτίωσης τους. Θα κάνουμε μία σύντομη αναφορά στα κεφάλαια που περιλαμβάνει η εργασία αυτή. Στην αρχή γίνεται μια γνωριμία με τον τομέα της Βιοιατρικής Τεχνολογίας, τις εφαρμογές αυτού και τους κλάδους που τον συνθέτουν. Εν συνεχεία, δίνονται κάποιες εισαγωγικές έννοιες σε σχέση με τα βιολογικά σήματα καθώς και οι βασικές αρχές επεξεργασίας αυτών. Κατόπιν προσεγγίζονται βασικές έννοιες φυσιολογίας του καρδιοκυκλοφοριακού συστήματος και της αιμοσφαιρίνης, καθώς διαδραματίζει σημαντικότατο ρόλο στην πειραματική μας διαδικασία. Ακολουθεί η περιγραφή της πειραματικής διάταξης καθώς και τα αποτελέσματα που προέκυψαν από τις πειραματικές διαδικασίες που πραγματοποιήθηκαν στο εργαστήριο μας. Στα επόμενα τρία κεφάλαια πραγματοποιείται η επεξεργασία των σημάτων μας αρχικά με τη βοήθεια του μετασχηματισμού Fourier και έπειτα με τη χρήση μιας σειράς κατωδιαβατών φίλτρων εφαρμοσμένων στα σήματα φωτεινότητας αλλά και στις εικόνες που προέκυψαν από το πειραματικό μέρος της εργασίας. Παραθέτουμε τα αποτελέσματα και τα συμπεράσματα μας από τη μελέτη αυτών. Τέλος,γίνεται αναφορά στις βασικές αρχές που διέπουν την απορρόφηση του φωτός κια στις βασικές διεργασίες που συνtελούν στη λειτουργία αυτή. / In this paper we dealt with finding the heartbeat of a person with digital image processing techniques in the near and mid infrared range. We used a series of infrared emitting diodes spectrum and a CCD video camera with which we got to test data. We rely on the status of hemoglobin to absorb the infrared light of certain wavelength. By editing visual materials resulting from our measurements using appropriate methods we can get closer to finding the rhythm, studying the biological signals. In the beginning there is an introduction to the field of medical technology, applications and industries such as it is composed. Then, we present some introductory concepts in relation to biological signals and the basic principles of processing. Afterwards, we approached concepts of circulation physiology and the properties of hemoglobin, as it plays a crucial role in our experimental procedure. We also describe the experimental setup and the results of the experimental procedures performed in our laboratory. The next three chapters are about the processing of signals using the Fourier transformation and then we use a series of low-pass filters applied to luminance signals and images obtained from the experimental part. Then we refer to the results and conclusions from our study which shows similarities between the heart rate curve and the luminance curve. Finally, reference is made to the basic principles governing the absorption of light,as it is the basic feature used to interpret our results.

Made available in DSpace on 2015-05-14T13:21:10Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-05-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Neste trabalho, estabelecemos a existência de uma solução simétrica positiva, como também uma solução não-simétrica que muda de sinal, para o problema elíptico semilinear u + V (z)u = f(z; u); u 2 H1(RN); onde N 4; V : RN ! R é um potencial não-negativo e f : RNR ! R é uma função contínua. Para obtermos os resultados, usamos o Teorema do Passo da Montanha, o Princípio de Criticalidade e resultados de compacidade.