977 resultados para mathematics support


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Nickel and palladium dispersed on titania support were submitted to reductive treatment, under hydrogen, at 200 and 500 ºC. After the reductive thermal treatment the materials were exposed to carbon monoxide (10 Torr) and analyzed in the infrared region. The increasing of the electronic density in the metallic d subshell, produced by the reductive thermal treatment, was monitored by the infrared stretching band shift of carbon monoxide adsorbed and it was interpreted as a consequence of the metal-support interactions. The highest effect was observed for Pd/TiO2 system. From the FTIR spectra was also observed that the hydrogen spillover was stronger on Pd/TiO2 than Ni/TiO2 system.

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Programming and mathematics are core areas of computer science (CS) and consequently also important parts of CS education. Introductory instruction in these two topics is, however, not without problems. Studies show that CS students find programming difficult to learn and that teaching mathematical topics to CS novices is challenging. One reason for the latter is the disconnection between mathematics and programming found in many CS curricula, which results in students not seeing the relevance of the subject for their studies. In addition, reports indicate that students' mathematical capability and maturity levels are dropping. The challenges faced when teaching mathematics and programming at CS departments can also be traced back to gaps in students' prior education. In Finland the high school curriculum does not include CS as a subject; instead, focus is on learning to use the computer and its applications as tools. Similarly, many of the mathematics courses emphasize application of formulas, while logic, formalisms and proofs, which are important in CS, are avoided. Consequently, high school graduates are not well prepared for studies in CS. Motivated by these challenges, the goal of the present work is to describe new approaches to teaching mathematics and programming aimed at addressing these issues: Structured derivations is a logic-based approach to teaching mathematics, where formalisms and justifications are made explicit. The aim is to help students become better at communicating their reasoning using mathematical language and logical notation at the same time as they become more confident with formalisms. The Python programming language was originally designed with education in mind, and has a simple syntax compared to many other popular languages. The aim of using it in instruction is to address algorithms and their implementation in a way that allows focus to be put on learning algorithmic thinking and programming instead of on learning a complex syntax. Invariant based programming is a diagrammatic approach to developing programs that are correct by construction. The approach is based on elementary propositional and predicate logic, and makes explicit the underlying mathematical foundations of programming. The aim is also to show how mathematics in general, and logic in particular, can be used to create better programs.

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Mc Taggart's celebrated proof of the unreality of time is a chain of implications whose final step asserts that the A-series (i.e. the classification of events as past, present or future) is intrinsically contradictory. This is widely believed to be the heart of the argument, and it is where most attempted refutations have been addressed; yet, it is also the only part of the proof which may be generalised to other contexts, since none of the notions involved in it is specifically temporal. In fact, as I show in the first part of the paper, McTaggart's refutation of the A-series can be easily interpreted in mathematical terms; subsequently, in order to strengthen my claim, I apply the same framework by analogy to the cases of space, modality, and personal identity. Therefore, either McTaggart's proof as a whole may be extended to each of these notions, or it must embed some distinctly temporal element in one of the steps leading up to the contradiction of the A-series. I conclude by suggesting where this element might lay, and by hinting at what I believe to be the true logical fallacy of the proof.

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Abstract: In this article we analyze the key concept of Hilbert's axiomatic method, namely that of axiom. We will find two different concepts: the first one from the period of Hilbert's foundation of geometry and the second one at the time of the development of his proof theory. Both conceptions are linked to two different notions of intuition and show how Hilbert's ideas are far from a purely formalist conception of mathematics. The principal thesis of this article is that one of the main problems that Hilbert encountered in his foundational studies consisted in securing a link between formalization and intuition. We will also analyze a related problem, that we will call "Frege's Problem", form the time of the foundation of geometry and investigate the role of the Axiom of Completeness in its solution.

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Bakgrund Demokratiska samhällen är sårbara och historiskt sett sällsynta. Förutsättningarna för en fungerande demokrati innefattar mer än formella institutioner eller enbart frånvaron av diktatorer och extremgrupper. För att en regim skall fungera enligt demokratiska principer behövs medborgare som stöder demokratiska värden. Därför är det av vikt att förstå de processer som får individer att känna tilltro till demokratiska värden. Trots att man kan anta att stöd för sådana värderingar utvecklas som ett resultat av social inlärning är de konkreta omständigheterna som leder till ett dylikt lärande mindre uppenbara. Den klassiska litteraturen beträffande politisk socialisation lyfte fram föräldrarna som avgörande för de ungas medborgerliga fostran, men i moderna samhällen har föräldrarna sällan som en uttalad målsättning att försöka påverka sina barns nuvarande eller framtida politiska preferenser. Den föreliggande studiens mål var att fördjupa diskursen kring politisk socialisation gen om att analysera föräldraskapets betydelse för demokratiska värderingar hos ungdomar. Metod Den föreliggande studien utgick från två slumpmässiga urval. Det ena omfattade 1341 studerande, 17 år gamla, inom andra stadiets utbildning i tre regioner i Finland (södra, syd-västra och västra) och det andra 678 studerande, 16 år gamla vid studiens inledande, från den flamländska delen av Belgien. Studien innefattade frågeformulär som besvarades under skoltid. Resultat De centrala resultaten från studien kan sammanfattas i fyra punkter. För det första kunde empatiskt tänkande konstateras vara en god förklarande variabel för ungdomars demokratiska värderingar (Artikel 1). För det andra gav studien stöd för antagandet att stödjande föräldraskap är av betydelse för utvecklingen av empati under ungdomsåren (Artikel 2). För det tredje utvärderades empati, i relation till andra betydelsefulla variabler, som förklarande variabel för demokratiska värderingar (Artikel 3). För det fjärde gav den föreliggande studien bevis för att demokratiskt föräldraskap, både direkt och indirekt, är relaterat till demokratiska värderingar hos ungdomar. Sammanfattning Sammanfattningsvis visade den föreliggande studien hur föräldraskap både direkt och indirekt kan påverka demokratiska värderingar hos ungdomar och hur dessa resultat kunde användas för demokratisk samhällsfostran.

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The purpose of this research is to draw up a clear construction of an anticipatory communicative decision-making process and a successful implementation of a Bayesian application that can be used as an anticipatory communicative decision-making support system. This study is a decision-oriented and constructive research project, and it includes examples of simulated situations. As a basis for further methodological discussion about different approaches to management research, in this research, a decision-oriented approach is used, which is based on mathematics and logic, and it is intended to develop problem solving methods. The approach is theoretical and characteristic of normative management science research. Also, the approach of this study is constructive. An essential part of the constructive approach is to tie the problem to its solution with theoretical knowledge. Firstly, the basic definitions and behaviours of an anticipatory management and managerial communication are provided. These descriptions include discussions of the research environment and formed management processes. These issues define and explain the background to further research. Secondly, it is processed to managerial communication and anticipatory decision-making based on preparation, problem solution, and solution search, which are also related to risk management analysis. After that, a solution to the decision-making support application is formed, using four different Bayesian methods, as follows: the Bayesian network, the influence diagram, the qualitative probabilistic network, and the time critical dynamic network. The purpose of the discussion is not to discuss different theories but to explain the theories which are being implemented. Finally, an application of Bayesian networks to the research problem is presented. The usefulness of the prepared model in examining a problem and the represented results of research is shown. The theoretical contribution includes definitions and a model of anticipatory decision-making. The main theoretical contribution of this study has been to develop a process for anticipatory decision-making that includes management with communication, problem-solving, and the improvement of knowledge. The practical contribution includes a Bayesian Decision Support Model, which is based on Bayesian influenced diagrams. The main contributions of this research are two developed processes, one for anticipatory decision-making, and the other to produce a model of a Bayesian network for anticipatory decision-making. In summary, this research contributes to decision-making support by being one of the few publicly available academic descriptions of the anticipatory decision support system, by representing a Bayesian model that is grounded on firm theoretical discussion, by publishing algorithms suitable for decision-making support, and by defining the idea of anticipatory decision-making for a parallel version. Finally, according to the results of research, an analysis of anticipatory management for planned decision-making is presented, which is based on observation of environment, analysis of weak signals, and alternatives to creative problem solving and communication.

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Many research works have being carried out on analyzing grain storage facility costs; however a few of them had taken into account the analysis of factors associated to all pre-processing and storage steps. The objective of this work was to develop a decision support system for determining the grain storage facility costs and utilization fees in grain storage facilities. The data of a CONAB storage facility located in Ponta Grossa - PR, Brazil, was used as input of the system developed to analyze its specific characteristics, such as amount of product received and stored throughout the year, hourly capacity of drying, cleaning, and receiving, and dispatch. By applying the decision support system, it was observed that the reception and expedition costs were exponentially reduced as the turnover rate of the storage increased. The cleaning and drying costs increased linearly with grain initial moisture. The storage cost increased exponentially as the occupancy rate of the storage facility decreased.

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The cassava starch industries generate a large volume of wastewater effluent that, stabilized in ponds, wastes its biogas energy and pollutes the atmosphere. To contribute with the reversion of this reality, this manipueira treatment research was developed in one phase anaerobic horizontal pilot reactor with support medium in bamboo pieces. The reactor was excavated into the ground and sealed with geomembrane in HDPE, having a volume equal to 33.6 m³ and continuous feeding by gravity. The stability indicators were pH, volatile acidity/total alkalinity ratio and biogas production. The statistical analyses were performed by a completely randomized design, with answers submitted to multivariate analysis. The organical loads in COD were 0.556; 0.670; 0.678 and 0.770 g L-1 and in volatile solids (VS) of 0.659; 0.608; 0.570 and 0.761 g L-1 for the hydraulic retention times (HRT) of 13.0; 11.5; 10.0 and 7.0 days, respectively. The reductions in COD were 88; 80; 88 and 67% and for VS of 76; 77; 65 and 61%. The biogas productions relatively to the consumed COD were 0.368; 0.795; 0.891 and 0.907 Lg-1, for the consumed VS of 0.524; 0.930; 1.757 and 0.952 Lg-1 and volumetric of 0.131; 0.330; 0.430 and 0.374 L L-1 d-1. The reactor remained stable and the bamboo pieces, in visual examination at the end of the experiment, showed to be in good physical conditions.

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Attempting to associate waste treatment to the production of clean and renewable energy, this research sought to evaluate the biological production of hydrogen using wastewater from the cassava starch treatment industry, generated during the processes of extraction and purification of starch. This experiment was carried out in a continuous anaerobic reactor with a working volume of 3L, with bamboo stems as the support medium. The system was operated at a temperature of 36°C, an initial pH of 6.0 and under variations of organic load. The highest rate of hydrogen production, of 1.1 L.d-1.L-1, was obtained with application of an organic loading rate of 35 g.L-1.d-1, in terms of total sugar content and hydraulic retention time of 3h, with a prevalence of butyric and acetic acids as final products of the fermentation process. Low C/N ratios contributed to the excessive growth of the biomass, causing a reduction of up to 35% in hydrogen production, low percentages of H2 and high concentrations of CO2in the biogas.

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ABSTRACT This study aimed to develop a methodology based on multivariate statistical analysis of principal components and cluster analysis, in order to identify the most representative variables in studies of minimum streamflow regionalization, and to optimize the identification of the hydrologically homogeneous regions for the Doce river basin. Ten variables were used, referring to the river basin climatic and morphometric characteristics. These variables were individualized for each of the 61 gauging stations. Three dependent variables that are indicative of minimum streamflow (Q7,10, Q90 and Q95). And seven independent variables that concern to climatic and morphometric characteristics of the basin (total annual rainfall – Pa; total semiannual rainfall of the dry and of the rainy season – Pss and Psc; watershed drainage area – Ad; length of the main river – Lp; total length of the rivers – Lt; and average watershed slope – SL). The results of the principal component analysis pointed out that the variable SL was the least representative for the study, and so it was discarded. The most representative independent variables were Ad and Psc. The best divisions of hydrologically homogeneous regions for the three studied flow characteristics were obtained using the Mahalanobis similarity matrix and the complete linkage clustering method. The cluster analysis enabled the identification of four hydrologically homogeneous regions in the Doce river basin.

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The purpose of this thesis is to study how Russian entrepreneurs perceive Finnish institutional environment and innovation support policies provided in the country, as well as to present a practical example in form of a case study of one technology oriented start-up firm which was established in Finland by Russian entrepreneurs. The empirical research of the thesis is conducted qualitatively in two parts. First part is conducted through online questionnaire with open questions in order to review the perceptions of Russian entrepreneurs in general. Second part is based on personal interviews with case company’s founders with the focus on the process of establishing the company in Finland. In the first part of the empirical research, five Russian start-up firms were contacted, and four responses were received. All of these responses were qualified for further analysis. The findings of the first part of the research reveal that Russian entrepreneurs have rather positive attitudes towards Finnish institutional innovation support policies. However, most of the entrepreneurs stated that they are unlikely to create their presence in Finland. As an outcome of the second part of the research, the process of establishing a case company in Finland is illustrated. In order to be able to establish companies in Finland, Russian entrepreneurs who have a permanent residence outside European Economic Area (EEA) are required to apply for a permission to perform business operations in the country. In addition, the established company must engage in improving the economical stand of the country by creating new work places, raising tax revenues, develop technologies and generate innovations in the country.