1,721,028 research outputs found
Using data compression in relational databases systems.
No full textIt is common to store huge amount of data in relation databases. Despite that storage is cheap, data compression might look like a viable alternative. In this Bachelor thesis author explores data compression features in popular reliational data- base systems. Author delves into performance impact of data compression. In first chaper of this paper data compression features in popular relational database system is described. In second chapter author defines methodoloygy for mesuring space savings and impact on query performance. Third chapter contains of results that author acquired by applying methodology on select dababase systems. Results are defined and applied methodology for mesuring impact of data compression
Using grid computing to investigate biocatalytic processes.
No full textThe purpose of this master thesis was to develop a methodology, which would assure an efficient way to use computing grids for computer models modeling biocatalytic processes. After researching possibilities to use computing grids for modeling of such processes, a methodology was presented, which can be used independently of grid middleware. Methodology was implemented on BalticGrid. By applying this methodology biocatalytic processes in biosensors were investigated. Operation of biosensor is described with mathematical model, which in general case is solved with computer model. Computer models of biosensors are commonly parameterized, and in most cases same problem is being solved only with different set of parameters. Such processes can be solved by using computational grids. Methodology presented in this paper was used to compare quasi steady state and detailed models of chemically modified biosensors. After examining methodology presented in this paper it was proved that this methodology can be used efficiently to research biocatalytic processes. Effectiveness of applying this methodology in concrete computational grid was estimated and suggestions were presented how to apply this methodology in an efficient way
Comparison of methods for calculation of the apparent michaelis constant using computational modelling of biosensors.
No full textIn this paper 8 different methods for calculating apparent Michaelis constant are compared using computational modelling of biosensors. It has been experimentally determined that methods for calculating the values of Michaelis-Menten kinetic parameters can be used depending on the value of biosensor’s diffusion module. Research findings show that when the diffusion module does not exceed 1, all of the analyzed methods can be used to calculate approximate values of apparent Michaelis constant. It is concluded that Ridders’ method is the most effective at calculating apparent Michaelis constant with more precision, and the methods for calculating the values of Michaelis-Menten kinetic parameters are more effective at relatively rough estimations of apparent Michaelis constant
Modeling and exploration of reaction-diffusion processes in amperometric biosensor with chemically modified electrode.
No full textThe aim of master thesis is to model amperometric biosensor with chemically modified electrode, introducing into existing model one more additional mediator layer. Mediator concentration inside the layer is changing during the biosensor action. Master thesis content consists of: enzyme kinetics introduction, biosensor modeling peculiarities exploration, chemically modified electrode information, biosensor action aspects description. Following chapter concentrates on mathematical modeling of particular biosensor type. Mathematical model represents differential equations with partial derivatives describing the reactions and diffusion inside biosensor. Next, numerical model is formulated. The explicit method technique was used. Based on numerical model software was made and validated. Using software the biosensor action was simulated in order to investigate biosensor properties and characteristics. In this work several properties were analyzed: impact of substrate and mediator concentrations, size of mediator, enzyme and diffusion layers, mediator layer diffusion coefficient on biosensor response. This model was compared with previous introduced model and it was shown that there is some difference between them and there is a reason to use new model
Computational modelling of biosensors with rough surface of the enzyme layer.
No full textIn this work approximation error of two-dimensional biosensor with rough surface model to one-dimensional model was analysed. Two-dimensional model was solved using altering directions implicit method, one-dimensional model - using implicit differences method. In order to decrease number of parameters in the analysing model, mathematical model of biosensor was changed to dimensionless mathematical model. Approximation error dependence of different enzyme surface geometries, enzyme layer thickness and initial substrate concentration was investigated
SQL methods for data secrecy assurance in relational database management systems.
No full textThis paper focuses on the methods of the data secrecy using SQL methods in relational database management systems (RDBMS). At the beginning, data secrecy, its features in relational databases and the goal of the secrecy assurance method are defined. The problem that data secrecy assurance methods vary between different databases and some RDBMS’s may lack some methods is covered. The focus is put on the table column encryption method which does not exist in some RDBMS’s. Many implementations of this method can be found, therefore some alternatives are covered and the decision of the chosen one are reasoned. This results in a methodology which defines the implementation of the method in any RDBMS and in any database schema. Features of the methodology are found through experiments, which can be repeated again to forecast exact features on another device. The main focus is on performance - how using the methodology affects the performance of simple SQL queries. One case is when a table has a fixed number of encrypted columns and different encryption algorithms are used and another case is when the same encryption algorithm is used on a table with a different number of encrypted columns. A dependency function is found in the results between the total SQL query execution time and the number of encrypted columns or used encryption algorithms
Computational Modelling of Biosensors of Complex Geometry.
No full textBiosensors are analytical devices mainly used to detect analytes and measure their concentrations. Mathematical modeling is widely used for optimizing and analyzing an operation of biosensors for reducing price of development of new biosensors. The object of this research is mathematical and computer models, describing an operation of biosensors, made of several parts with different properties. The dissertation covers models, formulated in one and two-dimensional spaces by partial differential equations with non-linear members, and solved numerically, using the method of finite differences. The numerical models are implemented by a computer program. An original mathematical model for a biosensor with a carbon nanotube electrode is presented in the dissertation. The conditions at which the one-dimensional mathematical model can be used instead of two-dimensional one for accurate prediction of the biosensor response are investigated. Elements, used to build models of biosensors with a complex structure, were systemized. The biosensor description language is proposed and the computer software, simulating an operation of biosensors in the one-dimensional space and a rectangular domain of the two-dimensional space, is developed. An adequateness of the model for the biosensor with the carbon nanotube electrode and the impact of structural and geometrical properties on a response of the biosensor were investigated, performing computer experiments using the developed software
Numerical and symbolic modeling of reaction-diffusion processes in bioreactors.
No full textIn this thesis, the mathematical and computational models of bioreactors based on microbioreactors are considered. The aim of this thesis is set - to properly simulate and optimize microbioreactor-based bioreactor systems by proposing original mathematical and computational models. Generalizations of mathematical models are proposed by taking into account the additional layers of the microbioreactor and the initial and boundary conditions, as well as a new mathematical model of the microreactor with carbon-nanotubes is formulated and proposed. The proposed model was validated with experimental data. By analyzing the model approximations, an algorithm based on the homotopy perturbation method to find approximate analytical solutions for previously unexamined models was proposed, and the accuracy of the approximations in two-layer biocatalysis systems was evaluated. A numerical model for multi-task optimization is also developed, which allows searching for optimal bioreactor configurations. Large-scale system simulation of proposed open and closed bioreactor systems has been performed
Ensuring javascript object notation in database management systems.
No full textEnsuring JavaScript Object Notation in database management systems
Static program analysis and tools ensuring it (.net).
No full textStatic program analysis and tools ensuring it (.NET)
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