Система управления качеством программного продукта на этапах разработки как фактор обеспечения конкурентоспособности компании

В процессе работы были выявлены факторы, влияющие на конкурентоспособность IT–компаний, и проанализированы характеристики качества программных продуктов. Также в ходе работы проводился анализ системы контроля качества программного продукта компании. В результате работы были разработаны и предложены рекомендации по совершенствованию контроля качества, которые помогут компании сэкономить время и деньги.In the course of the work, the factors influencing the competitiveness of IT-companies were identified, and the characteristics of the quality of software products were analyzed. Also in the course of the work, the analysis of the quality control system of the company's software product was carried out. As a result of the work, recommendations for improving quality control were developed and proposed, which will help the company save time and money

Использование инструментов Data Mining для анализа успеваемости студентов университета

В результате выполнения работы произведен анализ характеристик студентов и их успеваемости с помощью инструментов Data Mining. Были построены и сравнены между собой прогнозные модели, а также спроектировано и разработано веб-приложение.As a result of the work, the analysis of students' characteristics and their academic performance was performed using Data Mining tools. Predictive models were built and compared, and a web application was designed and developed

Loop-induced dark matter direct detection signals from gamma-ray lines

Improved limits as well as tentative claims for dark matter annihilation into gamma-ray lines have been presented recently. We study the direct detection cross section induced from dark matter annihilation into two photons in a model-independent fashion, assuming no additional couplings between dark matter and nuclei. We find a striking non-standard recoil spectrum due to different destructively interfering contributions to the dark matter nucleus scattering cross section. While in the case of s-wave annihilation the current sensitivity of direct detection experiments is insufficient to compete with indirect detection searches, for p-wave annihilation the constraints from direct searches are comparable. This will allow to test dark matter scenarios with p-wave annihilation that predict a large di-photon annihilation cross section in the next generation of experiments.Comment: 19 pages, 5 figures. v2: new XENON100 results included, references added. v3: matches published versio

Thermal and microbial gas generation, accumulation and dissipation in coal basins : role of sorptive storage capacity evolution

The regional variation of chemical and isotopic composition of coal gases has been investigated in the Upper Silesian Coal Basin (USCB), Czech Republic, and the Paraná Basin, Brazil. The field studies were complemented by laboratory experiments on selected samples to elucidate the effects of sorption/desorption processes on the chemical and isotopic composition of coal gases. Non-isothermal open system pyrolysis (Py-GC) was used to assess the gas generation potential and kinetics for the reconstruction of gas generation history in the study areas. The experimental results were integrated into a conceptual dynamic model of gas generation and storage in coal seams during structural and thermal basin evolution. Coal gases in the southern part of the USCB have a thermogenic isotope signature, while gases in the northern part have isotope signatures typical for microbial CO2 reduction and mixed thermogenic/microbial origin. Chemical and isotopic compositions of gas samples from canister desorption of coal cores showed larger variations, but were generally in agreement with those of samples taken from cross-measure boreholes. Canister desorption did not cause any systematic isotope fractionation effects. Trends in geochemical composition of thermogenic gases suggest a contribution of gas from deeper parts underlying the Carpathian overthrust. Coals from the two principal coal-bearing sequences of the USCB (paralic Ostrava Fm. and limnic Karviná Fm.) are vitrinite-rich, of high- to low-volatile bituminous rank and have mostly reached the stage of gas generation and expulsion. Using mass balance calculations the volumes of gas generated up to this coalification stage were estimated at 201 m³ per ton of Total Organic Carbon (TOC) for methane and 138 m³/t TOC for carbon dioxide. Cumulative pyrolytic methane yields ranged between 52 and 79 m³/t TOC. Based on the reaction-kinetic parameters obtained from these tests thermogenic gas generation at a geologic heating rate of 10-11 K/min was predicted to reach a maximum between 208 and 246°C. A 1D basin model of the subsidence and thermal history of the study area indicated that major gas generation occurred at maximum burial between 319 and 285 Ma b.p. and that no significant methane generation was associated with reburial in the Miocene. Excess sorption isotherms (up to 27 MPa) for methane and carbon dioxide under different experimental conditions showed that gas sorption capacity is mainly controlled by pressure, moisture content and temperature, whereas organic matter content and maturity have a lesser impact. The average methane sorption capacity of USCB coals of 15 m³/t was significantly higher than the present-day gas contents in the study area (< 2-10 m³/t). Correlations between sorption capacity, coal rank and temperature were derived from sorption experiments and used in combination with geological pressure and temperature data. A static model assuming present-day pressure and temperature gradients predicts an increase in sorption capacity with increasing depth towards a maximum value between 600 and 1000 m, followed by a decrease due to increasing temperature. Results from 1D burial history and temperature history modeling were integrated with experimental results to reconstruct the dynamic evolution of sorption capacity during basin history in relation to thermal gas generation. These computations revealed that the sorption capacity of the coals at maximum burial depth was significantly lower than estimated based on present-day pressure and temperature gradients. At the time of maximum gas generation, the amount of generated gas exceeded the sorption capacity of coals and the excess gas was expelled. Uplift started at the Carboniferous/Permian transition and the concomitant temperature decrease resulted in the presently observed under-saturation of the coal seams. From the end of the Permian uplift phase until present, coal seams of the Karviná formation were at temperatures below 80°C and thus amenable to microbial methane generation. In contrast, temperatures of coal seams of the Ostrava formation were significantly higher in the post-uplift phase and microbial methane generation from these coals was unlikely. Coal from the Santa Terezinha coalfield in the southern Paraná Basin, Brazil had a significantly lower residual gas generation potential than USCB coals. Gas contents and average gas sorption capacities were also lower. Methane and carbon dioxide sorption capacities of coals and shales correlated with the TOC. For CO2 the linear regression showed a non-zero intercept, indicating a significant sorption capacity of the mineral matter. The present-day gas content of coals from the Santa Terezinha coalfield amounts to 13-38% of the methane sorption capacity. Assuming sorption capacities at reservoir conditions theoretically an amount of up to 15.4 Gt CO2 could be stored in the Santa Terezinha coal seams, if all methane were produced prior to CO2 injection

Thermal and microbial gas generation, accumulation and dissipation in coal basins : role of sorptive storage capacity evolution

The regional variation of chemical and isotopic composition of coal gases has been investigated in the Upper Silesian Coal Basin (USCB), Czech Republic, and the Paraná Basin, Brazil. The field studies were complemented by laboratory experiments on selected samples to elucidate the effects of sorption/desorption processes on the chemical and isotopic composition of coal gases. Non-isothermal open system pyrolysis (Py-GC) was used to assess the gas generation potential and kinetics for the reconstruction of gas generation history in the study areas. The experimental results were integrated into a conceptual dynamic model of gas generation and storage in coal seams during structural and thermal basin evolution. Coal gases in the southern part of the USCB have a thermogenic isotope signature, while gases in the northern part have isotope signatures typical for microbial CO2 reduction and mixed thermogenic/microbial origin. Chemical and isotopic compositions of gas samples from canister desorption of coal cores showed larger variations, but were generally in agreement with those of samples taken from cross-measure boreholes. Canister desorption did not cause any systematic isotope fractionation effects. Trends in geochemical composition of thermogenic gases suggest a contribution of gas from deeper parts underlying the Carpathian overthrust. Coals from the two principal coal-bearing sequences of the USCB (paralic Ostrava Fm. and limnic Karviná Fm.) are vitrinite-rich, of high- to low-volatile bituminous rank and have mostly reached the stage of gas generation and expulsion. Using mass balance calculations the volumes of gas generated up to this coalification stage were estimated at 201 m³ per ton of Total Organic Carbon (TOC) for methane and 138 m³/t TOC for carbon dioxide. Cumulative pyrolytic methane yields ranged between 52 and 79 m³/t TOC. Based on the reaction-kinetic parameters obtained from these tests thermogenic gas generation at a geologic heating rate of 10-11 K/min was predicted to reach a maximum between 208 and 246°C. A 1D basin model of the subsidence and thermal history of the study area indicated that major gas generation occurred at maximum burial between 319 and 285 Ma b.p. and that no significant methane generation was associated with reburial in the Miocene. Excess sorption isotherms (up to 27 MPa) for methane and carbon dioxide under different experimental conditions showed that gas sorption capacity is mainly controlled by pressure, moisture content and temperature, whereas organic matter content and maturity have a lesser impact. The average methane sorption capacity of USCB coals of 15 m³/t was significantly higher than the present-day gas contents in the study area (< 2-10 m³/t). Correlations between sorption capacity, coal rank and temperature were derived from sorption experiments and used in combination with geological pressure and temperature data. A static model assuming present-day pressure and temperature gradients predicts an increase in sorption capacity with increasing depth towards a maximum value between 600 and 1000 m, followed by a decrease due to increasing temperature. Results from 1D burial history and temperature history modeling were integrated with experimental results to reconstruct the dynamic evolution of sorption capacity during basin history in relation to thermal gas generation. These computations revealed that the sorption capacity of the coals at maximum burial depth was significantly lower than estimated based on present-day pressure and temperature gradients. At the time of maximum gas generation, the amount of generated gas exceeded the sorption capacity of coals and the excess gas was expelled. Uplift started at the Carboniferous/Permian transition and the concomitant temperature decrease resulted in the presently observed under-saturation of the coal seams. From the end of the Permian uplift phase until present, coal seams of the Karviná formation were at temperatures below 80°C and thus amenable to microbial methane generation. In contrast, temperatures of coal seams of the Ostrava formation were significantly higher in the post-uplift phase and microbial methane generation from these coals was unlikely. Coal from the Santa Terezinha coalfield in the southern Paraná Basin, Brazil had a significantly lower residual gas generation potential than USCB coals. Gas contents and average gas sorption capacities were also lower. Methane and carbon dioxide sorption capacities of coals and shales correlated with the TOC. For CO2 the linear regression showed a non-zero intercept, indicating a significant sorption capacity of the mineral matter. The present-day gas content of coals from the Santa Terezinha coalfield amounts to 13-38% of the methane sorption capacity. Assuming sorption capacities at reservoir conditions theoretically an amount of up to 15.4 Gt CO2 could be stored in the Santa Terezinha coal seams, if all methane were produced prior to CO2 injection