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Parameter Identification for Elastic-plastic Material Models from Experimental Data
Jeník, Ivan ; Šebek, František (referee) ; Kubík, Petr (advisor)
This master's thesis deals with the identification of the material flow curve from record of tensile test of smooth cylindrical specimen. First, necessary theory background is presented. Basic terms of incremental theory of plasticity, tensile test procedure and processing its outputs are described. Furthermore, possibilities of mathematical expression of the elastic-plastic material constitutive law, thus mathematical expression of the material flow curve itself. Mechanism of ductile damage of material is explained briefly as well. Overview of recent methods of the flow curve identification is given, focused on cases, when the stress distribution in a specimen is not uniaxial. That is either kind of analytic correction of basic formulas derived for uniaxial stress state, or application of mathematical optimization techniques combined with numerical simulation of the tensile test. Also unusual method of neural network is mentioned. For 8 given materials, the flow curve identification was performed using different methods. Namely by analytic correction, optimization, sequential identification and neural network. Algorithms of the last two methods were modified. Based on assessment of obtained results, application field and adjusting the parameters of single algorithms was recommended. It showed up, that an effective way to the accurate and credible results is the combination of different methods during flow curve identification procedure.
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Materials of pietra dura artistic technique: composition, properties, provenance and possible identification
Jaroměřský, Štěpán ; Přikryl, Richard (advisor) ; Kuchařová, Aneta (referee)
Pietra dura or Florentine mosaic is a method of assembling thin slices of variously colored minerals and rocks into meaningful patterns or scenes. This artistic technique experienced a significant flourishing in Rudolfine Prague, where many works were created by this technique with materials that have not been described in detail yet. Although decorative carbonate rocks are frequently found in works made by the technique of pietra dura, decorative siliceous materials of jasperoid character, colored red, ochre or green, are equally important. This diploma thesis deals with the mineralogical and material research of these siliceous materials. One of the main objectives of the thesis was to explore possible discriminatory characteristics of siliceous materials from Czech localities, especially from the Kozákov area, which is historically documented as a deposit of jasperoid materials since at least the 16th century. The focus of the thesis lies in a set of mineralogical-petrographic and analytical methods of research. Using optical microscopy, scanning electron microscopy with energy dispersive spectroscopy, powder X-ray diffraction, Raman spectroscopy, Mössbauer spectroscopy and observation in ultraviolet light, it was possible to determine the minerals contained in the studied jasperoid materials....
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The ways of identification gifted student with dual exceptionality by the first degree of elementary school's teacher
Wagnerová, Lucie ; Kadrnožková, Monika (advisor) ; Marádová, Eva (referee)
This thesis deals with methods of identification of a gifted student with dual exceptionality by a teacher at the 1st grade of elementary school. The aim of the work is to find out what specific methods teachers use to identify students with dual exceptionality. Do they use available identification methods for educators, or do they have their own tested procedures for identifying this group of gifted students. The aim is also to find out how the cooperation between teachers and experts of the school counseling office takes place in the identification of twice exceptional pupils. The theoretical part contains the characteristics of basic concepts such as giftedness, dual exceptionality, identification, methods of identification, specific learning disorders. Giftedness can occur with different types of handicaps, this thesis focuses on the combination of giftedness with specific learning disabilities that appears most often in the schools (participating in the research). That is the reason why specific learning disabilities are described in the theoretical part. Further there are introduced the basic types of pedagogical identification methods and some types of psychological tests for identifying the mental abilities of the pupill. The empirical part is solved by the case study method. The subject of...
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Methods of Stakeholder Identification in Evaluation
Strašilová, Eva ; Remr, Jiří (advisor) ; Tuček, Milan (referee)
This text deals with the issue of identification of stakeholders in the evaluation. The concept of stakeholders is defined first, and the characteristics of the evaluation approaches are presented. Later is presented the position of the world evaluation societies on the stakeholders. There are four methods of stakeholder identification: 1) Brainstorming, 2) General list, 3) Questions and 4) The snowball method. Own research focuses on methods of identification of stakeholders in evaluations in the Czech Republic. Data sources are evaluations of OP and ROP programs. Secondary and content data analysis was used to analyse the data. The result of the research is that specific methods of stakeholder identification have not been applied in OP and ROP evaluations. Based on the results of the research, a new procedure for identification of stakeholders in the evaluation was formulated.
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Parameter Identification for Elastic-plastic Material Models from Experimental Data
Jeník, Ivan ; Šebek, František (referee) ; Kubík, Petr (advisor)
This master's thesis deals with the identification of the material flow curve from record of tensile test of smooth cylindrical specimen. First, necessary theory background is presented. Basic terms of incremental theory of plasticity, tensile test procedure and processing its outputs are described. Furthermore, possibilities of mathematical expression of the elastic-plastic material constitutive law, thus mathematical expression of the material flow curve itself. Mechanism of ductile damage of material is explained briefly as well. Overview of recent methods of the flow curve identification is given, focused on cases, when the stress distribution in a specimen is not uniaxial. That is either kind of analytic correction of basic formulas derived for uniaxial stress state, or application of mathematical optimization techniques combined with numerical simulation of the tensile test. Also unusual method of neural network is mentioned. For 8 given materials, the flow curve identification was performed using different methods. Namely by analytic correction, optimization, sequential identification and neural network. Algorithms of the last two methods were modified. Based on assessment of obtained results, application field and adjusting the parameters of single algorithms was recommended. It showed up, that an effective way to the accurate and credible results is the combination of different methods during flow curve identification procedure.
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