Innovative Security Technology for Optical Fiber Data Transmission Using Optical Vortex

This article presents system concept of the use of an optical vortex phenomenon for secure data exchange in the optical fiber line. Optical vortices are obtained in free space, and then they are introduced into the optical fiber. Their properties are examined in the world [1-2], so far, which directly shows the ability to increase the bandwidth of optical fiber. Given the structure and characteristics of the optical vortex, the authors propose to set a secure optical link. Such link can be provided in two ways.The first method involves coding an information on optical vortex. The data in the optical fiber line can be coded by time-position modeling of the optical properties of the vortex. In addition, changing the topology of the optical vortex and the use of mode dependencies also offer the possibility of information coding.The second way to use the vortex in the optical fiber is setting of optical fiber sensor, sensitive to the disturbance of fiber-optic transmission line. It can be achieved by propagation both - coded information in basic mode and an optical vortex in a microstructural fiber. In the case of physical impact on optical fiber the vortex disturbs the flow of data, forming the information noise on the output of the fiber.The article presents the setup of the generation of optical vortex, for the telecommunications bandwidth, developed at the Institute of Optoelectronics, in the Security Systems Group and initial tests of the setu

Retail government bonds in the Czech Republic

Tato diplomová práce popisuje a analyzuje projekt emise spořících státních dluhopisů. Spořící státní dluhopisy jsou nedávnou novinkou ve financování českého státního dluhu. Upisovateli emise spořících státních dluhopisů jsou přímo domácí či zahraniční občané. Úvodní části práce zasazují spořící státní dluhopisy do kontextu současného vývoje na finančním trhu i vývoje českých veřejných financí. V hlavní části jsou spořící státní dluhopisy analyzovány z pohledu potenciálních investorů. Výsledky investiční analýzy ilustrují, nakolik výhodný je úpis spořících státních dluhopisů, což potvrzuje i statistika všech tří dosud proběhlých emisí. V závěrečné části práce jsou spořící státní dluhopisy analyzovány též z pohledu ostatních zúčastněných subjektů. Tento přístup upozorňuje na nevýhody a nedostatky projektu emise spořících státních dluhopisů.This thesis describes and analyses the project of the retail government bonds emission. The retail government bond is a new product in the area of the Czech government debt financing. The subscribers of the retail government bonds are directly the citizens as well as foreigners. In the first part of the thesis the retail government bonds are situated into the context of recent development of the financial market as well as development of Czech public finances. In the main part of the thesis the retail government bonds are analysed from the investor's point of view. The results of this investment analysis illustrate what a bargain the retail government bonds are, which is confirmed by the statistics of all emissions up to date. In the final section of the thesis the retail government bonds are analysed also from the other subject's point of view. This approach points out the disadvantages of the project of the retail government bonds emission

Credit card and electronic money systems

The Bachelor's thesis deals with the description and distinction of terms "payment instrument" and "electronic money". After the introduction I concentrate on definitions of basic terms, that consequently appear in the thesis, I focus on separation of terms "funds" and "payment instrument". Then I deal with credit cards and electronic banking. In the second part of the thesis I describe electronic money as a subset of funds and the difference between credit card and electronic wallet. Finally I mention future trends of both credit card and electronic wallet systems and I outline the possible development of credit cards

Biologia roztoczy kurzu domowego [Acari: Astigmata: Pyroglyphidae]

This article is a first part of the rewiev of the house-dust-mite-atopy problem data. It includes informations on biology of these mites with emphasis of medical aspect and control. We hope that these informations will be of considerable interest to many readers because of the greatly increased investigations into the role of house dust mite sensitivity in allergic diseases

Relations between excretion of indole melanogen (TPM) and time of exposure to solar radiation

Introduction. In the human skin exposed to ultraviolet (UV) radiation, melanogenesis occurs in two stages, accompanied by urinary excretion of Thormalen-positive melanogen (TPM). In Poland, no data are available on the course and intensity of melanogonesis in relation to UV exposure in an industrial region. Material and methods. The Thormalen test was used for the collected samples (N=136) as modified by Matous and Suchoń. Results. Maximum environmental TPM content (0.67 μg/dm3) was observed in August. Conclusion. The time of UV exposure and local type of solar radiation promote melanogenesis