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Start Over Creator Novák, Petr Date Unknown

3. Geomechanical parametres of the Podlesí granites and their relationship to seismic velocities

Creator:
Nováková, Lucie, Sosna, Karel, Brož, Milan, Najser, Jan, and Novák, Petr
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, žuly, pórovitost, granites, porosity, Poisson’s ratio, seismic waves, Young’s modulus, shear modulus, 7, and 551
Language:
English
Description:
We studied the geophysical, physical, and geomechanical parameters of the Podlesí granites in the western part of the Krušné hory Mts., near the village of Potůčky. The granites represent a fractionated intrusion within the Nejdecký Massif. In total, the studied borehole is about 300 m deep. The samples were collected at depths of between 35 and 105 metres. Seismic P-wave and S-wave velocities were measured using ultrasonic scanning. The samples were water-saturated, unsaturated, and dried. The ultrasonic scanning system consisted of four piezoelectric sensors and a digital oscilloscope recorder. The wave frequency was 1 MHz. P-wave velocities range from 4400 m.s-1 to 6500 m.s-1 while S-wave velocities range from 2800 m.s-1 to 3800 m.s-1. These data were used to calculate dynamic Young’s modulus, dynamic shear modulus, and Poisson’s ratio. The deformational characteristics of the rock were specified from experimental loading of the sample with uniaxial strain. The shear and longitudinal deformation of each sample was measured using a resistive strain gauge fixed directly on the sample. Intermittent loading of the samples proceeded using a uniform gradient of axial stress of 1 MPa.s-1. The samples were subjected to five separate loads. During the tests, following parameters were recorded: stress, longitudinal deformation, and shear deformation. These data were used to calculate static Young’s and shear modulus, and Poisson’s ratio., Lucie Nováková, Karel Sosna, Milan Brož, Jan Najser and Petr Novák., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

4. Goodness-of-fit test for the Accelerated Failure Time model based on martingale residuals

Creator:
Novák, Petr
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
accelerated failure time model, survival analysis, and goodness-of-fit
Language:
English
Description:
The Accelerated Failure Time model presents a way to easily describe survival regression data. It is assumed that each observed unit ages internally faster or slower, depending on the covariate values. To use the model properly, we want to check if observed data fit the model assumptions. In present work we introduce a goodness-of-fit testing procedure based on modern martingale theory. On simulated data we study empirical properties of the test for various situations.
Rights:
http://creativecommons.org/publicdomain/mark/1.0/ and policy:public

9. Teorie sociálních reprezentací

Creator:
Novák, Petr
Type:
article, model:article, and TEXT
Subject:
diskurz, interpretace reality, sociální reprezentace, discourse, interpretation of reality, and social representations
Language:
Czech
Description:
Tato studie je rozdělena do tří hlavních částí: První pojednává o postavení sociálních reprezentací v systému současné psychologie a možnostech jejich využití pro současnou vědu a výzkum. Druhá se snaží vysvětlit okolnosti jejich vzniku a popisuje filosofickosociologické kořeny této teorie. Třetí část tohoto článku zkoumá jejich formální strukturu. Teorie sociálních reprezentací nikdy nebyla statickým a hypotetickým konstruktem, ale vždy se snažila pružně přizpůsobit stále se měnícímu kontextu reality. Sociální reprezentace jsou myšlenkami v pohybu, jsou to dynamické a otevřené fenomény a jejich koncept je formován a transformován spolu s měnícím se kontextem. Teorie sociálních reprezentací pomohla transformovat sociální psychologii na postmoderní vědeckou disciplínu, která překračuje hranice mezi psychologií, sociologií, filosofií, lingvistikou, teorií systémů a kulturní antropologií. Sociální reprezentace jsou souborem organizovaných a strukturovaných poznatků na úrovni základního společenského systému. Činí pro nás realitu srozumitelnou, bezpečnou a dávají nám možnost snadněji se v ní orientovat a sdílet ji s ostatními. and This study is divided into three main parts: The first is about position of social representations in the system of present psychology and possibilities of their use for present science and research. The second is trying to explain background of their origin and describes philosophical-sociological roots of this theory. The third part of this paper explores their formal structure. Theory of social representation has never been statistic and hypothetical construct, but has ever been trying to adapt flexibly to always changing context of reality. Social representations are ideas in movement, they are dynamic and open phenomena and their concept is formed and transformed together with the changing context. Theory of social representations helped to transform social psychology into postmodern science, which exceeds borders between psychology, sociology, philosophy, linguistics, theory of systems and cultural anthropology. Social representations are collection of organized and structured knowledges at the level of basic social system. They make the reality clear and safe for us. They give us possibility to orientate in reality easier and to share it with others.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

10. The matrix porosity and related properties of a leucocratic granite from the Krudum massif, West Bohemia

Creator:
Nováková, Lucie, Sosna, Karel, Brož, Milan, Jan Najser, and Novák, Petr
Format:
print, bez média, and svazek
Type:
article, články, model:article, and TEXT
Subject:
Geologie. Meteorologie. Klimatologie, skenovací elektronová mikroskopie, scanning electron microscopy, leucocratic granite, matrix porosity, geomechanical properties, hydraulic conductivity, ultrasonic velocities, 7, and 551
Language:
English
Description:
This paper investigates the matrix porosity and related properties of a leucocratic granite from the Krudum Massif, West Bohemia. The required samples were obtained from the 30-year old core of borehole KZ-25 (Material Documentation Depositories). In total, nine sample sets were taken from different depth levels within the borehole ranging from 18 m to 108 m. The hydraulic conductivity of the granite matrix was measured using a pressure cell whilst standard methods were employed to determine the dry density, connected porosity and total porosity. The pore size distribution was analysed using mercury porosimetry. The ultrasonic velo cities were measured using a pulse source and oscilloscope. Dynamic Young’s modulus, dynamic shear modulus, Poisson’s ratio, static Young’ s modulus, uniaxial compressive strength and moisture were determined according to measurements of ultrasonic velocities and deformability in uniaxial compression. The morphology and structure of the pore network was studied using high reso lution scanning electron microscopy. The overall porosity values defined by the different porosimetry methods follow the same trends although the absolute values differ according to the specific method. A logarithmic relationship was found to exist between hydraulic conductivity and porosity within the granite matrix. In addition, a slight depth dependence was noted in the porosity, hydraulic conductivity, bulk density, and ultrasonic velocities of the granite matrix. The SEM images have allowed precise mapping and detailed de scription of the pore network., Lucie Nováková, Karel Sosna, Milan Brož, Jan Najser and Petr Novák., and Obsahuje bibliografické odkazy
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public