Aktualumas. Moksleivių fizinis aktyvumas yra vienas iš veiksnių veikiančių jų kūno laikyseną, nes įtakoja griaučių-raumenų sistemos funkcinę būklę. Taikant įvairias fizinio aktyvumo formas yra lavinama griaučių-raumenų sistema, ugdant žmogaus raumenų greitumą, jėgą, ištvermę, sąnarių paslankumą, judesių koordinaciją, stiprinant silpnąsias raumenų grupes, (Hawes, 2003; Bayar et al., 2004; Predel & Tokarski, 2005). Pastaraisiais metais tiek Lietuvoje, tiek ir užsienio šalyse moksleivių fizinis aktyvumas mažėja, o didejantys mokymosi krūviai daro poveikį sėslesnio gyvenimo būdo dominavimui. Moksleivių sėdint mokyklos suole, stuburui tenka didesnis krūvis nei stovint ar vaikštant, todėl yra didesnė tikimybė, kad gali pasikeisti stuburo slankstelių padėtis bei funkcija (Hänninen & Koskelo, 2003; Butkienė, 2009). Tyrimo objektas – 9-12 klasių moksleivių kūno laikysenos sąsajos su fiziniu aktyvumu. Tyrimo tikslas – išanalizuoti 9-12 klasių moksleivių kūno laikysenos sąsajas su fiziniu aktyvumu. Tyrimo uždaviniai: 1..Nustatyti 9-12 klasių moksleivių fizinį aktyvumą. 2. Palyginti neturinčių ir turinčių laikysenos problemų moksleivių fizinį aktyvumą. Tyrimo metodai: 1. Anketinė apklausa (IPAQ). 2. Matematinė statistika. Tyrimo organizavimas. 2012-2013 mokslo metais buvo atlikta anketinė apklausa Kauno miesto Pilėnų vidurinėje mokykloje ir Saulės bei Dariaus ir Girėno gimnazijose 9-12 klasėse. Naudojant IPAQ fizinio aktyvumo (FA) tyrimo anketą, apklausti 106... [toliau žr. visą tekstą] / Relevance. Physical activity is one of the factors indirectly affecting the body posture. It heavily influence the functional condition of the skeletal-muscular system: different forms of physical activity develop the muscular-skeletal system, train the skeletal muscle strength, endurance, joint flexibility, movement coordination, strengthening weak muscle groups, and influencing the balance between muscles (Hawes, 2003; Bayar, 2004; Predel, 2005). Pupils’ physical activity has a tendency to degrees, and the increasing learning workloads lead to a more sedentary lifestyle. Sitting places undue strain on the spine compared to standing or walking (Hӓnninen, 2003). It is therefore mo re likely that long-term sitting can eventually after the function and the condition of the backbone structures. The object of research are the links of body posture with physical activity among 9- 12 grade pupils. The aim of research is to analyse the links of body posture with physical activity among 9- 12 grade pupils. Objectives of the study: 1. To determine the physical activity of 9- 12 grade pupils. 2. To compare the physical activity of pupils with and without posture problems. Research methods: 1. Questionnaire survey (IPAQ). 2. Mathematical statistics. Study organization. The questionnaire survey was carried out in grades 9- 12 in the academic year of 2012- 2013 at Pilėnai Sencondary School, city of Kaunas, and at Darius and Girėnas Gymnasium. A total of 106 pupils were surveyed using the... [to full text]

There is an increasing demand for multimedia services in heterogeneous wireless networks. Considering the highly dynamic wireless channels and the relatively large size of the multimedia data, how to support efficient and reliable multimedia delivery is a pressing issue. In this dissertation, we investigate the multimedia delivery algorithms in heterogeneous wireless networks from three different aspects. First, we study the single-flow rate adaptation of video streaming algorithm over multiple wireless interfaces. In order to maintain high video streaming quality while reducing the wireless service cost, the optimal video streaming process with multiple links is formulated as a Markov Decision Process (MDP). The reward function is designed to consider the quality of service (QoS) requirements for video traffic, such as the startup latency, playback fluency, average playback quality, playback smoothness and wireless service cost. To solve the MDP in real time, we propose an adaptive, best-action search algorithm to obtain a sub-optimal solution. To evaluate the performance of the proposed adaptation algorithm, we implemented a testbed using the Android mobile phone and the Scalable Video Coding (SVC) codec and conducted experiments with real video flow. Then, with the multiple multimedia flows competing for limited wireless resources, we propose a utility-based scheduling algorithm for multimedia transmission in Drive-thru Internet. A utility model is devised to map the throughput to user's satisfaction level in terms of multimedia data quality, such as Peak Signal-to-Noise Ratio (PSNR) of video. The objective of the scheduling problem is to maximize the total utility. Then the optimization problem is formulated as a finite-state decision problem with the assumption that future arrival information is known, and it is solved by a searching algorithm as the benchmark. To obtain a real-time solution, a practical heuristic algorithm based on the concept of utility potential is devised. We further implemented the solution and conducted extensive simulations using NS-3. Finally, the multimedia dissemination problem in large-scale VANETs is investigated. We first utilize a hybrid-network framework to address the mobility and scalability issues in large-scale VANETs content distribution. Then, we formulate a utility-based maximization problem to find the best delivery strategy and select an optimal path for the multimedia data dissemination, where the utility function has taken the delivery delay, the Quality of Services (QoS) and the storage cost into consideration. We obtain the closed-form of the utility function, and then obtain the optimal solution of the problem with the convex optimization theory. Finally, we conducted extensive trace-driven simulations to evaluate the performance of the proposed algorithm with real traces collected by taxis in Shanghai. In summary, the research outcomes of the dissertation can contribute to three different aspects of multimedia delivery in heterogeneous wireless networks. First, we have proposed a real-time rate adaptation algorithm for video streaming with multiple wireless interfaces, to maintain the high quality while reducing the wireless services cost. Second, we have presented an optimal scheduling algorithm which can maximize the total satisfaction for multimedia transmission in Drive-thru Internet. Third, we have derived the theoretical analysis of the utility functions including delivery delay, QoS and the storage cost, and have obtained an optimal solution for multimedia data dissemination in large-scale VANETs to achieve the highest utility. / Graduate / 0984 / 0544

This is a report on research done in the field of mathematical physics. It is an investigation of the concept of the linking number between two simple and closed spatial curves. The linking number is a topological invariant with scientific applications ranging from DNA biology to Topological Quantum Field Theory. Our aim is to study C ̆alug ̆areanu’s theorem, also called White’s formula, which relates the linking number to the concepts of twist and writhe. We are interested in the limit of the two curves as they approach each other. To regulate this, we introduce a regularization method that utilizes a point-split. Further we explore if the result is dependent on how the regularization is introduced. Therefor we inflict an asymmetry in the regularization, with a parameter a in the point-split intervals, to check whether the result becomes dependent on a or not. We find that the result is independent of the parameter a.

Tikslas: Nustatyti Kauno miesto pirmų klasių mokinių fizinio aktyvumo ir mitybos ypatumus bei jų sąsajas su tėvų sveikatos būkle. Uždaviniai: Įvertinti pirmokų fizinį aktyvumą; Išanalizuoti pirmokų mitybos ypatumus; Įvertinti subjektyvią tėvų sveikatos būklę; Nustatyti vaikų mitybos ir fizinio aktyvumo ypatumų sąsajas su suaugusių šeimos narių sveikatos būkle. Tyrimo metodika: šis magistro darbas parengtas atlikus Lietuvos vaikų augimo stebėsenos tyrimą, kuris buvo vykdomas vadovaujantis PSO Europos vaikų nutukimo stebėsenos iniciatyvos (angl. WHO European Childhood Obesity Surveillance Initiative – COSI) protokolo. Magistro darbe buvo atliktas mitybos įpročių, fizinio aktyvumo ir tėvų subjektyvios sveikatos vertinimas. Magistrinio darbo tikslinė grupė – Kauno miesto pirmų klasių mokiniai ir jų tėvai. Tiriamąjį kontingentą sudarė 6–8 metų vaikai (n=407; 51,1 proc. berniukų ir 48,9 proc. mergaičių) ir jų tėvai (n=407). Rezultatai: nustatyta, kad beveik du trečdaliai berniukų ir mergaičių (atitinkamai 60,1 proc. ir 61,8 proc.) lanko sporto ir /ar šokių būrelius. Du penktadaliai berniukų ir mergaičių (40 proc.) būrelius lanko 2 dienas per savaitę. Nustatyta, kad savaitgaliais ilgai (>2 val.) televizorių žiūri beveik visi pirmokai (93,6 proc.). Vertinant mokinių mitybą nustatyta, kad du trečdaliai (67 proc.) pirmokų pusryčiauja kasdien. Dažniausiai pirmų klasių mokiniai varotoja šviežių vaisių (62,4 proc.), virtų daržovių (58,7 proc.). Tėčių ir mamų turinčių antsvorio ar... [toliau žr. visą tekstą] / The goal of the thesis: to identify the relations between pecularities of first-graders‘ nutrition and physical activity and health status of their parents in Kaunas city. Objectives:To evaluate the first-graders’ physical activity; To analyse the peculiarities of first-graders’ nutrition; To evaluate the health status of parents of first-graders; To find relations between pecularities of first-graders‘ nutrition and physical activity and health status of their parents. Methods: This master thesis is based on Lithuanian children's growth monitoring study, which was carried out in accordance with the WHO European Childhood Obesity Surveillance Initiative - COSI protocol. Master thesis analyses habits of nutrition, physical activity and subjetive evaluation of parents‘ health. Target group of the research is first grade students and their parents in Kaunas city. Generally, the research study consists of 6-8 year old children and their parents. A total number of participants of the survey is 407 first-graders (51.1 percent boys and 48.9 per cent girls) and 407 parents. Results: The survey shows that almost two thirds of boys and girls (60.1 per cent and 61.8 percent) attend sports and/or dance clubs. The largest proportion (two fifths) of boys and girls attends clubs two times a week. The research shows that almost all of first-graders (93,6 per cent) spend a lot time (more than two hours) watching television on weekends. The nutrition survey shows that 67 per cent of children... [to full text]

This dissertation investigates Ultra-Wideband (UWB) techniques for the next generation Radio Frequency Identification (RFID) towards the Internet-of-Things (IoT). In particular, an ultra-high frequency (UHF) wireless-powered UWB radio (UHF/UWB hybrid) with asymmetric links is explored from system architecture to circuit implementation. Context-aware, location-aware, and energy-aware computing for the IoT demands future micro-devices (e.g., RFID tags) with capabilities of sensing, processing, communication, and positioning, which can be integrated into everyday objects including paper documents, as well as food and pharmaceutical packages. To this end, reliable-operating and maintenance-free wireless networks with low-power and low-cost radio transceivers are essential. In this context, state-of-the-art passive RFID technologies provide limited data rate and positioning accuracy, whereas active radios suffer from high complexity and power-hungry transceivers. Impulse Radio UWB (IR-UWB) exhibits significant advantages that are expected to overcome these limitations. Wideband signals offer robust communications and high-precision positioning; duty-cycled operations allow link scalability; and baseband-like architecture facilitates extremely simple and low-power transmitters. However, the implementation of the IR-UWB receiver is still power-hungry and complex, and thus is unacceptable for self-powered or passive tags. To cope with μW level power budget in wireless-powered systems, this dissertation proposes an UHF/UWB hybrid radio architecture with asymmetric links. It combines the passive UHF RFID and the IR-UWB transmitter. In the downlink (reader-tag), the tag is powered and controlled by UHF signals as conventional passive UHF tags, whereas it uses an IR-UWB transmitter to send data for a short time at a high rate in the uplink (tag-reader). Such an innovative architecture takes advantage of UWB transmissions, while the tag avoids the complex UWB receiver by shifting the burden to the reader. A wireless-powered tag providing -18.5 dBm sensitivity UHF downlink and 10 Mb/s UWB uplink is implemented in 180 nm CMOS. At the reader side, a non-coherent energy detection IR-UWB receiver is designed to pair the tag. The receiver is featured by high energy-efficiency and flexibility that supports multi-mode operations. A novel synchronization scheme based on the energy offset is suggested. It allows fast synchronization between the reader and tags, without increasing the hardware complexity. Time-of-Arrival (TOA) estimation schemes are analyzed and developed for the reader, which enables tag localization. The receiver prototype is fabricated in 90 nm CMOS with 16.3 mW power consumption and -79 dBm sensitivity at 10 Mb/s data rate. The system concept is verified by the link measurement between the tag and the reader. Compared with current passive UHF RFID systems, the UHF/UWB hybrid solution provides an order of magnitude improvement in terms of the data rate and positioning accuracy brought by the IR-UWB uplink. / QC 20120110

Este trabalho apresenta proposta de modelo matemático para o problema de expansão do sistema de transmissão baseado no fluxo de carga CC considerando a utilização de links CC e FACTS resolvido através de metodologia de solução que considera a primeira e a segunda lei de Kirchhoff em processo enumerativo de branch-and-bound adaptado. A abordagem possui dois pontos em destaque: i) apresenta uma proposta de modelo matemático com possibilidade da utilização direta em problemas de expansão de linhas de transmissão que possuem tanto linhas de transmissão CA, transformadores, links CC e dispositivos FACTS e ii) é um método exato de solução do problema que garante a otimalidade da resposta e traz uma contribuição ao tradicional método branch-and-bound por incluir relaxações adicionais. O método aplicado aos sistemas de 6 barras de Garver e sistema Sul sudeste Brasileiro de 46 barras apresenta respostas adequadas e o modelo matemático testado em um sistema Garver modificado apresenta novas configurações possíveis com redução do custo total do investimento. / This work proposes a mathematical model to the transmission expansion system problem based on the DC power flow model considering the use of DC links and FACTS that is solved using a solution method considering the first and second Kirchhoff’s Law in an enumerative adapted branch-and-bound process. It is possible to highlight two key aspects of the proposed approach: i) presents a mathematical model that can be directly used on expansion transmission systems problems that have AC transmission lines, transformers, DC links and FACTS and ii) is an exact solution method that guarantees the optimum problems’s solutions and contributes to the traditional branch-and-bound method bringing additional relaxations. The solution method applied to Garver’s six-bus network and southeast Brazilian 46 bus network provides correct answers and the mathematical model tested on a modified Garver’s six-bus network presents new possible configurations that enables overall cost reduction to the problem.

The diploma thesis suggests methods and forms of geography teaching in the second stage of the primary school aimed at the theme of quality of life. The themes of the suggested subject matters are the influence of the environment on quality of life of people, difference in quality of life in rural and urban areas, comprehension of the concept of quality of life and quality of life of the elderly. The concept of quality of life is situated into the context of the Framework Education Programme for Basic Education and the chosen curriculum of Základní Škola pod Svatou Horou in Příbram. Didactic evaluation of the given topic in chosen textbooks of geography for the second stage of primary schools is a part of the thesis. The theoretical concept based on expertise literature is connected with themes of Didactics, cross-curricular approaches, key competences, methods and forms of teaching. The research surveying pupil's problem-solving competence focused on the topic of quality of life is realized among 28 pupils and 11 teachers by way of questionnaire survey.

The diploma thesis deals with topics in the teaching of geography of religion at the 2nd grade of elementary school. The aim of the thesis is to create own educational material focused on the geography of religion, which will develop pupils in the key competences resulting from interdisciplinary relationships. The theoretical part is devoted to the classification of teaching methods and their characteristics. Futher, the issue of geography of religion is placed in the context of RVP ZV and monitored at selected schools. From the point of view of the given topic, attention is also paid to the didactical evaluation of geography textbooks for the 2nd level of primary schools with the current MŠMT clause. At the end of the thesis there is a proposal of own teaching material in the form of various activities that will interestingly approach pupils to the given topic.

[pt] Com a crescente utilização de sistemas de acesso sem fio ponto-multiponto em banda larga, operando em freqüências cada vez mais elevadas, cresce também a necessidade do desenvolvimento de novos modelos, mais precisos e consistentes, para a previsão da atenuação por chuvas, principal efeito da propagação em freqüências superiores a 10 GHz. Este trabalho apresenta uma modelagem semi-empírica para a previsão do comportamento estatístico da atenuação por chuvas em enlaces rádio terrestres ponto-a- ponto e via satélite. Os modelos foram desenvolvidos com base em resultados de medições conjuntas de taxa de precipitação e atenuação por chuvas em diversas regiões do Brasil, realizadas no período de desenvolvimento deste trabalho, além de medidas de várias partes do mundo, disponíveis no banco de dados de propagação da União Internacional de Telecomunicações (UIT-R). Os modelos desenvolvidos permitem obter a distribuição cumulativa de probabilidades da atenuação por chuvas a partir da distribuição da taxa de precipitação medida ou estimada na região do enlace. Embora existam diversos modelos propostos na literatura para previsão da atenuação em enlaces terrestres ou em enlaces via satélite, duas características importantes não são encontradas, conjuntamente, na maioria deles: utilizar, como base para a previsão, a distribuição da taxa de precipitação em toda a faixa de percentagens de tempo de interesse, e não apenas em um ou dois pontos; e manter consistência entre os modelos para os casos terrestre e via satélite. Além não de atender a estes requisitos, os modelos propostos apresentam erros de previsão menores ou equivalentes aos dos principais modelos da literatura, quando testados contra os resultados disponíveis de medidas em enlaces reais. / [en] The development of new technologies for broadband wireless access, using increasingly higher frequencies, points to the necessity of more accurate methods for rain attenuation, that represents the most serious impairment for radio systems operating in frequencies above 10 GHz. This work presents semi-empirical models for the prediction of rain attenuation in terrestrial and satellite links. The models were developed using data obtained in concurrent measurements of rain attenuation and point rainfall rate in different regions of Brazil. Some of these measurements were performed as part of this work and some were already available from previous measurements campaigns. Data available in the UIT-R data banks of propagation measurements were also used, in order to develop global methods. The models that have been developed allow the prediction of the cumulative probability distribution of rain attenuation from the cumulative distribution of point rainfall rate in the region of the link. Although several methods with these purpose can be found in the technical literature, the ones developed in this work present some important features that are not found, as a whole, in any of those models: they use the full rainfall rate distribution over the entire range of time percentages of interest; the terrestrial and satellite models are consistent, that is, the elements used in the terrestrial prediction model are kept in the satellite prediction model that involves a mor complex geometry. Besides that, the models proposed show an excelent performance in terms of prediction error, when compared with measured data.

Este trabalho apresenta proposta de modelo matemático para o problema de expansão do sistema de transmissão baseado no fluxo de carga CC considerando a utilização de links CC e FACTS resolvido através de metodologia de solução que considera a primeira e a segunda lei de Kirchhoff em processo enumerativo de branch-and-bound adaptado. A abordagem possui dois pontos em destaque: i) apresenta uma proposta de modelo matemático com possibilidade da utilização direta em problemas de expansão de linhas de transmissão que possuem tanto linhas de transmissão CA, transformadores, links CC e dispositivos FACTS e ii) é um método exato de solução do problema que garante a otimalidade da resposta e traz uma contribuição ao tradicional método branch-and-bound por incluir relaxações adicionais. O método aplicado aos sistemas de 6 barras de Garver e sistema Sul sudeste Brasileiro de 46 barras apresenta respostas adequadas e o modelo matemático testado em um sistema Garver modificado apresenta novas configurações possíveis com redução do custo total do investimento. / This work proposes a mathematical model to the transmission expansion system problem based on the DC power flow model considering the use of DC links and FACTS that is solved using a solution method considering the first and second Kirchhoff’s Law in an enumerative adapted branch-and-bound process. It is possible to highlight two key aspects of the proposed approach: i) presents a mathematical model that can be directly used on expansion transmission systems problems that have AC transmission lines, transformers, DC links and FACTS and ii) is an exact solution method that guarantees the optimum problems’s solutions and contributes to the traditional branch-and-bound method bringing additional relaxations. The solution method applied to Garver’s six-bus network and southeast Brazilian 46 bus network provides correct answers and the mathematical model tested on a modified Garver’s six-bus network presents new possible configurations that enables overall cost reduction to the problem.