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Lokalizace zdrojů akustické emise pomocí neuronových sítí na základě časových profilů
Chlada, Milan ; Blaháček, Michal ; Převorovský, Zdeněk
Correct localization of acoustic emission (AE) sources is a basic requirement in AE analysis and consequent evaluation of damage mechanism. The localization procedures using artificial neural networks (ANN) represent today highly effective, alternative approach to classical triangulation algorithms. Nevertheless, their application possibilities are limited due to problematic collecting of sufficiently extensive training and testing data sets together with the non-portability of particular trained network to any other object. A new ANN-based approach, using so-called signal arrival time profiles, is proposed to overcome both limitations. Such approach provides the ANN training on numerical models and allows the application of learned ANN on real structures of various scales and materials. This enables considerable extension of ANN application possibilities. New method is illustrated on experimental data obtained during pen-tests on a steel plate, and its remarkable advantages are discussed.
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The Difference between Planed and Real Measured Dose under the Bolus Made of New Material
KUKAČKOVÁ, Lucie
The first chapter of the theoretical part of the bachelor's thesis outlines radiotherapy in general. Radiotherapy is a clinical treatment using ionising radiation to treat malignant and benign diseases. It is one of the youngest medical disciplines. The development of radiotherapy began in November 1895, when Wilhelm Conrad Röntgen discovered X-rays. Radiotherapy became an independent medical specialty in 1922. The second chapter describes planning in radiotherapy. Irradiation plans for radiotherapy are created on the basis of a planning system. ECLIPSE planning system is used in the oncology department in České Budějovice Hospital. Phantoms are the theme of the third chapter. Phantoms are materials whose radiation absorption corresponds to human tissue. Water is a basic universal phantom material. In addition to water, also other materials are used, such as polystyrene, plexiglass, paraffin, PMMA etc. The last, fourth chapter of the theoretical part, deals with boluses. Boluses are tissue-equivalent materials that are put on the patient's skin during irradiation when it is needed to increase the surface dose and at the same decrease the depth dose. Moreover, bolus is used to compensate the missing tissue. Bolus is most often used to diagnose patients after mastectomy due to breast cancer. The most important characteristic of boluses is their ability to absorb radiation. In the oncology department in České Budějovice Hospital, bolus from dental wax Ceradent had been used before. A bolus made from this material was hard and uneasy to shape. That is why it did not fit tightly to the chest wall of the patient. For this reason a new line of boluses was obtained for the oncology department, from gel material supplied by CIVCO company with dimensions 30 x 30 cm and thickness 0.3 cm, 0.5 cm and 1 cm, in "skin" and "skinless" version. These new boluses stick easily to the patient's skin and copy the shape of the body. The first objective of my bachelor's thesis was to compare the doses planned and measured under the bolus from the new material. This objective is elaborated in the practical part of the bachelor's thesis in chapter presenting the results. Another objective was to elaborate the principles for the use of bolus. These principles are described in the theoretical part of the bachelor's thesis in chapter describing the use of bolus in radiotherapy. The following hypothesis was suggested in the thesis: "It can be assumed that the generated bolus in the planning system corresponds to the scanned bolus on the CT with patient and that there is a difference between the planned dose and measured one." To confirm or refute the working hypothesis, measuring was executed in the oncology department in České Budějovice Hospital. Data about individual doses were collected boluses generated in the Eclipse planning system of different width (0.3 cm, 0.5 cm, 1 cm) on phantoms. Three types of phantoms from PMMA were used for the purposes of this measuring. First, the measuring was executed on phantom in the shape of the chest wall of a patient after breast ablation. Then, the tabular phantom and universal IMRT verification phantoms were used. The measurement was executed on the Clinac 2100 C/D linear accelerator, later on the new TrueBeam 2.5. linear accelerator. All these doses were measured by ionisation chamber from PTW company with volume of 0.125cm3. The obtained data were processed in tables and deviations of individual doses were calculated. Based on this measurement it was found out that the deviations of all doses are less than 3%. And therefore also the hypothesis of the thesis was confirmed. There really is a difference between individual doses, but not so significant to affect the size of dose during the planning. As for the practical outcome, generated boluses will be used as standard in the oncology department in České Budějovice Hospital.
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Relationship between use of television and new media in spectator habits of teenagers at secondary schools
Pražáková, Hana ; Reifová, Irena (advisor) ; Vochocová, Lenka (referee)
The thesis named Relationship between using TV and new media in the habits of secondary school teenagers is trying to identify ways of using common TV broadcasting and TV contents reachable with a help of new media by czech secondary school teenagers. It also examines their relationship towards above mentioned delivery technologies and contents. In the theoretical part the attention is paid not only to the specific category of adolescent viewers and video content users, but to technological and social aspects that can influence ways and motives for using TV contents as well. This thesis also touches current issue of television studies, which has arrised together with new digital technologies arrival . Practical part is with a help of quantitative and qualitative research trying to reach empirically-based data, supporting and developing findings described in the theoretical part. Performed questionaire research results in statistically not yet recorded information about equipment (such as TV and PC with internet access) installed in teenagers' apartments. It is especially easy access to above stated technologies, what has the biggest impact on the way and intensity of using these technologies. Subsequent qualitative interviews, focus on motives and reasons leading to changes of teenaged viewers'...
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Lengths of new grapevine sprouts as a contribution to reconstruction of spring air temperatures in the 18th century
Střeštík, Jaroslav ; Verö, J.
Lengths of grapevine sprouts measured on the 24th April since 1740 and archived in the town museum in Köszeg have been compared with air temperatures observed in March and April at different station in the vicinity. Correlation coefficients reach more than 0.6 and decrease with the increasing distance from Köszeg. Also the long-term course of spring temperature and grapevine sprouts corresponds to each other. Correlation was higher when temperatures were compared with logarithms or square roots of the grapevine lengths. Correlations of the lengths with other quantities were poor. These results confirm that during 1740 to 1780 spring temperatures were relatively high, surely higher than those in the 19th century.
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Benefits of object-relational technology
Paľo, Martin ; Říha, Antonín (advisor) ; Kopecký, Michal (referee)
Lately, object-relational databases have become increasingly popular. Compared to the traditional approach, they provide many new possibilities. This thesis describes the general requirements on object- relationaJ systems and the new object-relationaJ enhancement of Oracle, as well as similar enhancements of other well-known database systems and their comparison with the SQL: 1999 database standard requirements. An essentia1 part of this thesis is concerned with the comparison of the relational and object-relational in1pJementation of the student information system using the Oracle 9i database server. Powered by TCPDF (www.tcpdf.org)
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Monetization of Online Content and Its Effect on the Reception of Blogs
Novotný, Marek ; Švelch, Jaroslav (advisor) ; Vochocová, Lenka (referee)
"Monetization of the internet content and its effect to the blogs reception" diploma thesis deals with journalism on the verge of the second decade of 21st century. Thesis describes changes, which are happening right now. It focuses on problems faced by traditional media and possibilites which are being opened for more agile on-line media. With the help of public opinion surveys, it shows views of the media consumers as well as those of media producers representatives. It also maps possible ways to monetize content as is advertising model, micropayments model, freemium or paywall and expounds advantages and disadvantages of each of them. In the next part it shows, how the monetization is used on different case studies, such as web server Motejlek.com, Slovakian media content subscription system Piano and successful American project The Huffington Post, which combines news aggregator with comments section and blogs. In its end the thesis is using the gathered knowledge and data to show strategies, which might be useful in today's fast changing world of media and on the other side shows weaknesses of some other concepts which author of the thesis doesn't accept as viable. Keywords Aggregator, blog, advertising, micropayments, monetization, Murdoch, new media, Piano, paywall
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Possible Applications of LNG in the Czech Republic
Machalová, Markéta ; Sedláček, Jiří (advisor) ; Kysilka, Hugo (referee)
This thesis evaluates the possibilities of application of LNG (liquefied natural gas) in the Czech Republic. LNG is a relatively new commodity, which has broad use in the world, but as of now, the Czech Republic hasn't entered its market. The main objective of this thesis is to determine whether there exists suitable use for LNG in the Czech Republic today. By analysis and calculation I came to the conclusion, that there are applications that would be economically advantageous and would, in addition, bring other significant benefits, such as reducing emissions. The most perspective is the use of LNG as an alternative truck fuel. Under certain conditions suitable applications are also LNG satellite stations, cogeneration or bus transport. The conclusion of this thesis is that liquefied natural gas has a great potential to expand to the Czech Republic.
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The arrival of new spirituality, Hinduism and spiritual Masters in the Czech Republic
Nykodýmová, Iveta ; Štampach, Ivan (advisor) ; Vojtíšek, Zdeněk (referee)
This text refers to the Indian religious beliefs, Hinduism in particular, that we can meet in the Czech Republic. Many people are interested in these religions and my question is 'what makes present man so interested in these religions and what is so attractive to them?' Foremost in my text there is basic information about Hinduism, including the myths, Gods and Goddesses and creeds. As the Indian culture is very diverse and rich I have only mentioned basic information for understanding the text well. Then I have described yoga in the text, Bhaktiyoga in particular. This type of yoga forms part of the Hare Khrisna movement. Both Yoga in Daily Life and the Hare Khrisna have already worked for many years and both have continuity with their Indian founders and came into our subconscious through their spiritual pursuit. I have described their influence in the Czech Republic on the basis of my questionnaire and even on my personal experience. Apart from these two movements this text refers to individual persons who are active in this kind of lifestyle. My conclusion is that these religious trends do not signify any danger or threat for our society; on the contrary it means that by helping us to find our way to God this enriches our daily lives. Powered by TCPDF (www.tcpdf.org)
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