National Repository of Grey Literature 145 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Stability of the sodium content in selected botanical reference materials
Kameník, Jan ; Kučera, Jan ; Borovička, Jan ; Havránek, Vladimír
Sodium mass fractions in NIST standard reference materials (SRM) SRM 1547 Peach Leaves and SRM 1515 Apple leaves determined by INAA in our laboratory in recent years has been higher than the certified values. Similarly, increased values were published for SRM 1547 by several other laboratories. The increased Na mass fractions was found also for freshly opened SRM 1547 bottle and for material originating from a different lab. Increased Na mass fractions were confirmed by ICP-MS analysis of both materials. Analysis of archived samples revealed that sodium mass fraction in materials stored in polyethylene capsules is in agreement with the certified values. The sodium content in the glass of SRM 1547 bottle was roughly 10 %. Direct measurement of the Na depth profile by micro-PIXE was not indicative whether Na is released, i.g., by a glass corrosion due to residual humidity in the botanical material. However, a model experiment with freshly prepared and pulverized peach leaves demonstrated that such a scenario is possible for leaf-based materials. Although the study was focused on two NIST materials, the process is possible for any material with rather low Na content.
Role of activation analysis in the preparation of reference materials
Kučera, Jan
The fundamentals of neutron activation analysis (NAA) and prompt gamma activation analysis (PGAA) and practices of both methods are briefly review, together with enlightening their specific role in the preparation of reference materials. The importance of homogeneity testing for the certification and use of reference materials (RMs) using NAA is appraised. Examples of the use of NAA and PGAA for the certification of element contents in environmental, biological, and material science RMs produced by world-leading institutions, such as U.S. NIST, IRMM, IAEA and by national institutions, as well, at the Nuclear Physics Institute within last almost 30 years are presented.
Provenancing of drugs based on their elemental composition determined by Neutron Activation Analysis - Feasibility Study
Kučera, Jan ; Kameník, Jan ; Sabol, J. ; Šesták, B. ; Kolář, P. ; Roman, M.
We analyzed five samples of heroine and five samples of cocaine seized in the Czech Repulic using instrumental neutron activation analysis (INAA). In the heroine speciments, we determined 16 trace elements in at least one of the samples analyzed, in the cocaine speciment, 9 trace elements could be determined. We have found remarkable differences, up to several orders of magnitude, in contents of the elements Na, Cl, Zna and Br, especially in the heroine samples. The accuracy of INAA results was proved by simultaneous analysis of a certified reference material NIST SRM 1547 Peach Leaves. The results of trace element determination in heroine samples are compard with those published by autors from abroad. The results obtained show a high potential of INAA for the drug elemental characteriaztion aimed at determination of their provenance, procedures used for their manufacturing and purification and cutting for the end users. The results achieved also suggest that it is desirable to analyze more samples with the final aim of establishing a database of elemental composition of drugs seized in the Czech Republic, which could possibly be extended later, in cooperation with foreign drug abuse and police bodies, at the international level.
The resistance of Pavel Glos during the Protectorate of Bohemia and Moravia
Kučera, Jan ; Županič, Jan (advisor) ; Zicha, Zbyněk (referee)
Main goal of this work is to describe the resistance activities of Pavel Glos during era of Protectorate of Bohemia and Moravia from the available sources. To put this activities to the context of all anti-Nazi resistance and to evaluate their benefits. Also map its transformations that were determined by the current situation, needs and objectives of the resistance movement. This aspect is much more important for Pavel Glose, who took part in resistance activity for the whole period of the Nazi occupation. The intention of this work is also to remind the personality of Pavel Glos, who acted as the parson of the Unitas Fratrum in Turnov. Although he is virtually unknown today, he was one of the prominent figures of the Czech anti-Nazi resistance. Among his close collaborators were Vladimír Krajina, Jaroslav Valenta and Rudolf Mareš. He also participated in the collaboration with the paratroop groups Antimony and Barium, which were sent to the Protectorate by the London Exile Government. The archive documents from the National Archives, Archives of Security Forces, the Military Central Archive and the Archive of the Unitas Fratrum, as well as historical and memoir literature were used during the processing of the work.
Body composition in children with different movement programm
Kučera, Jan ; Bunc, Václav (advisor) ; Kinkorová, Ivana (referee)
Title: Body composition in children with different movement programm Objectives: The main objektive of this work is analysis of body composition while using BIA method children of younger school age and consired differences in physical components with regard to different movement programm. Methodes: Body composition was measured by bioelectrical impedance analysis device Bodystat 1500. Data was processed in Microsoft Excel. Followed parameters are the percentage of body fat, the absolute amount of fat-free mass in kg, the proportion of total body water. The research participated in total 75 probands agend 10-11 years of average height 147,7 cm and weight 42,1 kg. The research includes regularly training 25 children from RC Mountfield Říčany (training 3 times a week + 2x physical education) with a medium to hight intensity exersice of 360 minutes per week, regularly training 25 children from Říčany Fight Club (2x weekly training + 2x physical education) with a medium to hight intensity exersice of 270 minutes per week and 25 children from the Nemo Říčany Elementary School where the physical education 90 minutes per week. The research group is made up of boys only, because girl with a higher percentage of total body fat have a higher BFM then boys. Results: The average proportion of body fat in boys...
Remote Configuration of P4 Device
Neruda, Jakub ; Kučera, Jan (referee) ; Wrona, Jan (advisor)
Administration of a large network from a central node with a vendor independent API is quite important issue these days. The concept of SDN was truly helpful with realization of the solution, namely in the form of the OpenFlow protocol. Nowadays, a P4 language is gaining momentum, primarily thanks to its ability to describe whole packet processing pipeline and also for the P4 Runtime, solution to the distributed network configuration. CESNET association is one of the research groups starting to support P4 in their network cards beloging to the Combo series. In this work, an API was designed for these cards, aimed at the dynamic flow table configuration. This API was used for implementation of a basic support of the Combo cards in the P4 Runtime.
System for Protection against DoS Attacks
Šiška, Pavel ; Wrona, Jan (referee) ; Kučera, Jan (advisor)
This bachelor's thesis deals with the design and implementation of the software part of the system for protection against DoS attacks. Nowadays Denial of Service attacks are quite common and can cause significant financial damage to internet or service providers. The main goal of this thesis was to provide software, which is focused on high-speed data throughput and can provide efficient protection against these attacks in 100 Gbps networks. Key part of the system, which is being developed in cooperation with CESNET, is hardware-accelerated network interface card, which can process incoming network traffic  at full wire-speed and does the operations laid down by the software part. The main task of the software is evaluation of the information about network traffic and managing actions of the hardware accelerator. The software part of the proposed system has been successfully implemented and the properties of the system have been verified in an experimental evaluation. During the work on this thesis the first implementation of the system has already been deployed in CESNET network infrastructure.
IPv6 Prefix Generator
Obrusník, Vojtěch ; Kučera, Jan (referee) ; Matoušek, Jiří (advisor)
Incoming deployment of IPv6 technology in larger scale requires existence of effective route lookup algorithms suitable of manipulation with long IPv6 prefixes. Development of such algorithms is dependent on an huge amount of test data sets, which do not exist at the moment. This paper is focused on design and implementation of a tool, that would be able to generate such test data sets. Study phase of IPv6 address allocation polices and analysis of currently available pieces of prefix sets took place before the implementation. Validation of results was performed by bit value and prefix length scatter measurement.
Netdev Driver for Acceleration COMBO Cards
Tran, Dominik ; Vrána, Roman (referee) ; Kučera, Jan (advisor)
This thesis deals with the development of the network device driver for the FPGA network COMBO cards, which should enable receiving and sending packets through standard network interface of Linux kernel. CESNET is developing a device called DDoS Protector for protection against an amplification (D)DoS attacks, which uses COMBO cards to achieve high performance. A SZE2 interface is used for high speed transfers of network data between COMBO card and a controlling software application, using technique of bypassing kernel network stack and other methods. DDoS Protector has to support standard network protocols, whose implementation directly on top of the SZE2 is very difficult. Instead, using kernel network stack, which is, by default, bypassed to achieve high performance, is much easier to implement and supports all sorts of protocols. Creation of the network device driver enables us to use kernel network stack and other network applications for COMBO cards. Based on the study of SZE2 interface and driver development, I designed and then successfully implemented network device driver. Driver was tested to ensure standard protocols work. It was also tested from the performance point of view. I have also developed the same type of driver for the newer interface - NDP and an application for an accelerated packet forwarding, both of which are functional and were not part of the thesis specification.
Comparison of IPv6 Prefix Set Generators
Vašek, Dominik ; Kučera, Jan (referee) ; Matoušek, Jiří (advisor)
This bachelor's thesis aims to compare the IPv6 generators. In the first part we introduce protocol IPv6 and the allocation policies of registrars in order to better understand the problem. Next, we introduce three existing prefix set generators, whose description is available. In the second part of the thesis we propose and implement a series of tests for the prefix set generators. Lastly, we test the generators and make a conclusion based on the results. According to our results, we conclude that the prefix sets from the NonRandom and IPv6Table generators have a large error in comparison with a target prefix set. However, V6Gene, the implementation of which is not currently publicly available, might generate prefix sets close to the reality based on its proposal.

National Repository of Grey Literature : 145 records found   1 - 10nextend  jump to record:
See also: similar author names
48 KUČERA, Jan
18 KUČERA, Jaroslav
24 KUČERA, Jiří
11 KUČERA, Josef
1 Kučera, J.
9 Kučera, Jakub
1 Kučera, Jaromír
18 Kučera, Jaroslav
24 Kučera, Jiří
3 Kučera, Jonáš
11 Kučera, Josef
3 Kučera, Jáchym
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