42 research outputs found
Even triangulations and commutative groups
No full textTitle: Even triangulations and commutative groups Author: Jan Luber Department: Department of Algebra Supervisor: prof. RNDr. Aleš Drápal, CSc., DSc. Abstract: This thesis takes interest in latin bitrades and triangulations construc- ted from them. Firstly, we introduce needed definitions, properties of the latin bitrades, detailed construction of the triangulation and mainly possibility of em- bedding latin bitrades into abelian groups. These groups are determined by the relations definied on vertices of the triangulation. Then we get concerned with a particular kind of 3-homogeneous latin bitrades which correspond to toroidal tri- angulation whose each vertex has degree six. For these groups we express relation matrix and complement to their torsion ranks. In case of simple triangulations we present explicit description of the groups and with modular arithmetic we get partial description even for more complex triangulations. Keywords: latin bitrade, eulerian triangulation, abelian grou
Hadamard matrices and their applications in cryptography
No full textTitle: Hadamard matrices and their applications in cryptography Author: Jan Luber Department: Department of Algebra Supervisor: prof. RNDr. Aleš Drápal, CSc., DSc., Department of Algebra Abstract: This thesis takes interest in Hadamard matrices, their constructions and application in cryptography. Firstly, we introduce basic properties of Hadamard matrices and selected summary of classical constructions is presented. Then we show a table of constructions that can be used to construct Hadamard matrix of given order. In the next part, we get concerned with Hadamard matrices with circulant cores with detailed description of construction Hadamard matrices with two circulant cores from GL-pair. In the end, we present cryptosystem using Hadamard matrices, we show its essential weaknesses and simple attacks. We propose several improvements in the form of adding other security elements. Keywords: Hadamard matrix, Hadamard conjecture, symmetric cryptograph
Even triangulations and commutative groups
No full textTitle: Even triangulations and commutative groups Author: Jan Luber Department: Department of Algebra Supervisor: prof. RNDr. Aleš Drápal, CSc., DSc. Abstract: This thesis takes interest in latin bitrades and triangulations construc- ted from them. Firstly, we introduce needed definitions, properties of the latin bitrades, detailed construction of the triangulation and mainly possibility of em- bedding latin bitrades into abelian groups. These groups are determined by the relations definied on vertices of the triangulation. Then we get concerned with a particular kind of 3-homogeneous latin bitrades which correspond to toroidal tri- angulation whose each vertex has degree six. For these groups we express relation matrix and complement to their torsion ranks. In case of simple triangulations we present explicit description of the groups and with modular arithmetic we get partial description even for more complex triangulations. Keywords: latin bitrade, eulerian triangulation, abelian grou
Deep Radio Observations and the Role of the Cosmic Web in Galaxy Evolution
No full textA current open question in the evolution of galaxies, is what are the physical mechanisms that cut off galaxies from their primordial gas reservoirs, resulting in the end of their star-formation capabilities? Recent observational programs have shown that the properties of galaxies show dependencies on their placement within the large-scale structure (LSS) of the universe. These observations have motivated recent developments in theoretical work that have shown how a galaxy\u27s interaction with the LSS may impact its connection to primordial gas supply, and ability to continue to accrete gas, the fundamental ingredient in star-formation.
In order to investigate the role of LSS in galaxy evolution, we use data from the COSMOS HI Large Extragalactic Survey (CHILES), a single pointing of the Very Large Array in the COSMOS field with the ability to detect HI in galaxies out to a redshift 0.45. We introduce a fast imaging pipeline that is able to produce science-ready image cubes of the CHILES data in a reasonable turnover time. This pipeline is applied to the full CHILES database and produces data of excellent sensitivity with minimal imaging artefacts. Additionally, we introduce the CHILES Continuum Polarization Survey (CHILES Con Pol), which is the most sensitive 1.4 GHz radio continuum survey, to date, at 4.5 resolution. We discuss the survey design, data processing, and comparison to other surveys taken in the COSMOS field and discuss their complementary aspects.
Using these high quality sensitive radio data, and ancillary data from the COSMOS survey, we investigate neutral hydrogen content and relative star-formation rate for blue, lower mass spiral galaxies as a function of their placement in their LSS, for two redshift bins. We find that the neutral hydrogen content for galaxies not near the spine of filaments, more than 2 Mpc away, is lower in our low-z bin. We place this result in the context of recent theoretical work and speculate that we are observing recent cosmic web detachment events for galaxies of these types, that result in the cutting-off of galaxies from their primordial gas supply
The upper Jurassic-lower cretaceous siliciclastic system in the Morocco offshore - Prevenance, transport and deposition
No full textThe Morocco segment of the Central Atlantic passive continental margin experienced km-scale exhumation during the early post-rift (late Jurassic-Early Cretaceous). In the Meseta and the High Atlas this led to the development of a N-S trending ridge sourcing terrigenous sediments which were brought to the Atlantic sea via wide rivers flowing on fairly flat plains. In correspondence with the W termination of the High Atlas, waters were deeper and no terrigenous sediments are found in the Lower Cretaceous. South of the High Atlas, exhumation followed a different pattern and led to the formation of a WSW-ENE striking topgraphic high which formed the first order divide of the region. Coeval sediments along the coast are sands to conglomerates deposited mainly in fluvial systems. The source-to-sink approach helps in predicting offshore distribution and characteristics of the sand bodies which form one of the most interesting reservoirs along the coast of NW Africa.Geoscience & EngineeringCivil Engineering and Geoscience
Legal Politics of Witness Protection Guarantee for Reporter of Election Criminal Violations as an Effort to Enforce Indonesian Election Laws
No full textThis study aims to determine the urgency of providing guarantees for the protection of reporter witnesses of election criminal violations in national law. This research is a normative legal research using literature research as the data collection method. The research method used is normative juridical based on statute approach. The results of this study indicate that there is no legal guarantee for the protection of reporter witnesses of election criminal offenses as a form of lex specialis of electoral law enforcement in Indonesia. Meanwhile, the guarantee of protection of the reporter\u27s witness is very necessary to maintain the stability of democracy in Indonesia which is characterized by the running of elections according to the principle of LUBER JURDIL. As a result, the author recommends that lawmakers formulate legal products, both in the form of laws and amendments to laws that are able to accommodate the needs of legal protection of reporting witnesses of election criminal offenses
A brief history of the Arnstein family : (For Katharine Arnstein) /
No full textHistory of the Arnstein family, dating back to Seckel Arnstein in 1751 and his ancestor Ahron Fraenkel in 1645, who established a printing press business in 1699. Seckel Arnstein continued the business of printing of Hebrew bibles, which became famous all over Central and Eastern Europe under the name “S. Arnstein & Sons”. Another predecessor, Leopold Arnstein, founded a dry goods store under the name “Leopold Arnstein & Sons”. Family history of Gustav and Richard Arnstein, the grandfather and father of the author. Gustav Arnstein was born in Sulzbach and raised his family together with his wife Nanette, née Luber, in Wertheim. Later they moved to Stuttgart. In 1907 Gustav Arnstein founded a security business (“Nachtwach- und Schliessdienst”) for local stores and factories. Assimilated life style. World War One. Marriage of the author’s parents Richard and Charlotte, née Heymann. Post-war depression and rise of Nazi movement. Immigration to the United States.The following individuals are named: Arnstein, Seckel, 1751-1825 ; Auer, Ignatz ; Heymann, Berthold ; Heymann, Charlotte ; Luber, Nanette ; Spitzer, Franz.Walter Arnstein was born in 1930 in Stuttgart, Germany. He immigrated together with his family to the United States in 1939, where he continued his education. After getting his Bachelor degree in Social Science he was drafted in the U.S. army during the Korean War (1950-1953). Marriage with Charlotte Sutphen in 1952 in New York. He received an M.A. degree in history at Columbia University and a Ph.D. degree at Northwestern University. Walter Arnstein was appointed Professor of History at the University of Illinois in 1968 until his retirement in 1998.Emigration and immigration, 1933-1945, EnglandGenealogyProfessions and occupations, businessmenProfessions and occupations, historiansProfessions and occupations, merchantsWorld War, 1939-194
