The impact of a spherical object onto a surface of a liquid, solid or granular material, is a configuration which occurs in numerous industrial and natural phenomena. The resulting dynamics can produce complex outcomes and often occur on very short time-scales. Their study thereby requires high-speed video imaging, as is done herein. This three-part dissertation investigates widely disparate but kindred impact configurations, where the impacting object is a solid steel sphere, or a molten metal droplet. The substrate, on the other hand, is either granular material, a liquid, or solid ice. Therefore both fluid mechanics and thermodynamics play a key role in some of these dynamics. Part I, investigates the penetration depth of a steel sphere which impacts onto a granular bed containing a mixture of grains of two different sizes. The addition of smaller grains within a bed of larger grains can promote a “lubrication” effect and deeper penetration of the sphere. However, there needs to be enough mass fraction of the smaller grains so that they get lodged between the larger grains and are not simply like isolated rattlers inside the voids between the larger grains. This lubrication occurs even though the addition of the small grains increases the overall packing fraction of the bed. We compare the enhanced penetration for the mixtures to a simple interpolative model based on the results for monodispersed media of the constitutive sizes. The strongest lubrication is observed for large irregular shaped Ottawa sand grains, which are seeded with small spherical glass beads. Part II, tackles the topic of a molten metal drop impacting onto a pool of water. When the drop temperature is far above the boiling temperature of water, a continuous vapor layer can form at the interface between the metal and water, in what is called the Leidenfrost phenomenon. This vapor layer can become unstable forming what is called a vapor explosion, which can break up the molten metal drop. We study the details of these explosions and characterize the metal debris. We contrast the results for two different metals, i.e. tin and a special metal alloy called Field’s metal. For tin the drop solidifies and forms a porous foam-like solid, whereas the Field’s metal breaks up into a multitude of spherical beads, with a range of sizes as small as a few microns. We attribute this difference to the much lower melting point of the Field’s metal, which is only 60oC, compared to 230oC for the tin. This allows more fragmentation of the Field’s metal drop before it solidifies. When the temperature of the impacting metal is increased, high-speed imaging reveals a sequence of up to three vapor explosions, each of increasing intensity. We measure the acceleration of the vapor interface and compare the size-distribution of the microbeads to the fastest growing instability mode of the corresponding Rayleigh-Taylor instability. Part III, investigates the coefficient of restitution when a steel sphere impacts on an ice surface. As observed in earlier studies the restitution coefficient is largest for the smallest impact velocities, where the surface is not greatly fragmented. Our focus is on greatly heating the sphere up to 400oC to investigate how the thermal load affects the short term interaction of the sphere with the ice. We see a clear trend where hotter spheres rebound less than cold spheres. We also track the speed of ice-fragments ejected during the earliest stages of the impact.

Aim of master’s thesis is design of Business Intelligence solution based on non commercial technology, consideration of installation costs, estimation of economic benefits and designing of final solution of currently unsatisfactory situation in company Fortemix s.r.o.

Master’s thesis proposes a solution of data and communication model in the ŽOS Trnava, a.s. and GOŠA FŠV. Thesis proposes model for customer, which generates reports for individual management areas.

In the doctoral thesis, the bi-layer ceramic bodies with core-shell geometry were prepared by thermoplastic co-extrusion method and for these composite bodies the mechanical properties were studied. For study of co-extrusion and mechanical properties were designed two composite systems. First system ZTA-A combined the dense core ZTA (zirconia-toughened alumina) and the dense shell Al2O3. Second system ZST-Z consisted of porous core and dense shell made from ZrO2 for both cases. In the thesis, the rheology of ceramic thermoplastic suspensions and their mutual influence during co-extrusion was studied. Subsequently, the debinding process and sintering were studied, and based on the optimization of all process steps were obtained defect-free bodies with core-shell geometry. The mechanical properties (elastic modulus, hardness and bending strength) were determined for sintered bodies. To estimate the stress path in the core shell bodies loaded in bending, the relationship considering different elastic moduli of the core and the shell was used. For bodies of ZTA-A system was increased the strength in comparison with monolithic bodies of the individual components. Thus, bodies with high surface hardness of shell from Al2O3 and moreover having high fracture strength in bending were obtained. The effective elastic modulus was decreased for bodies of ZST-Z system up to 25 % in comparison with the elastic modulus of dense monolithic samples. The same effective modulus of elasticity was possible to achieve with core-shell bodies while maintaining significantly higher fracture strength than monolithic porous bodies or pipes.

This master´s thesis deals with critical factors of management information systems implementation. In first part its describing the present state of the topic, defines the basic terminology, clarifies theoretical background and determines how to understand to a concept of management information systems. In next part is survey of current business intelligence solutions of three leaders of the world market and its detailed comparison, description of their basic properties their advantages and disadvantages. In Conclusion is detailed description of platform Tableau, its practical application, example of implementation, critical succes factors and benefits of its use in companies.

In retail, the explosion of data sources and data has provided incentive to invest in information systems (IS), which enable leaders to understand the market and make timely decisions to improve performance. Given that users’ perceptions of IS affects their use of IS, understanding the factors influencing user acceptance is critical to acquiring an effective business intelligence system (BIS) for an organization. Grounded in the technology acceptance model theory, the purpose of this correlational study was to examine the relationship between perceived usefulness (PU), perceived ease of use (PEOU), and user acceptance of business intelligence systems (BIS) in retail organizations. A 9-question survey was used to collect data from end-users of BIS in strategic managerial positions from retail organizations in the eastern United States who reported using BIS within the past 5 years. A total of 106 complete survey responses were collected and analyzed using multiple linear regression and Pearson’s product-moment correlation. The results of the multiple linear regression indicated the model’s ability to predict user acceptance, F(2,103) = 21.903, p < .000, R2 = 0.298. In addition, PU was a statistically significant predictor of user acceptance (t = -3.947, p = .000), which decreased with time as shown by the results from Pearson’s product-moment correlation, r = -.540, n = 106, p < .01. The implications of this study for positive social change include the potential for business leaders to leverage BIS in addressing the underlying causes of social and economic challenges in the communities they serve.

Purpose – The increasing amounts of data has become an important factor for organizations. A visual dashboard is a BI tool that can be used for communication of insights from big data. One way for individuals in organizations to get insights from timely and large data sets is through visualizations displayed in visual dashboards, but studies show that most of them fall short of their potential. Therefore, the aim of this study is to examine how individuals make use of visual dashboards. Design/Methodology – To obtain this understanding a literature review was performed, followed by a study conducted in two phases. Firstly, a multiple-case study of four organizations was performed, which included interviews and the think-aloud technique. Secondly, the findings from the multiple-case study were tested through interviews with experts in the BI area. Findings – The findings indicate that low democratization, scarce effects, and simplicity are reasons for why the use of visual dashboards is not fully exploited. Low attention and understanding combined with a lack of timely information means that data-driven actions are not taken. The phase of predictive analysis has not yet been reached, rather organizations are still using the visual dashboard for descriptive analysis, which in turn hinders the possibility for effects. For these reasons the use of visual dashboards does not meet the often described purpose to make better and faster decisions, and organizations are still to take steps in that direction. Research limitations – The sampling of industries in the multiple-case study could affect variables as number of KPIs.

This thesis deals with implementation of a new framework, which allows to define and generate demo data for the star schema structure. Work analyses and com-pares available demo data generators. In theoretical part of the thesis, there are described concepts and technologies using in the field of Business Intelligence. Practical part deals with the design and implementation of the framework. In the final section, there are actual examples of generated data and their possible rep-resentation (samples of possible reports and dashboards).

This work reports on the two-stream radiative transfer in a horizontally homogeneous turbid vegetation medium assuming bi-Lambertian leaf scattering by planar model leaves. The deduced two-stream radiative transport equations are solved analytically for various leaf architectures considering leaf normal distribution (LND) functions from purely vertical to purely horizontal leaves. These transfer models are driven by radiative energy flux densities (EFDs) incident at the top of the vegetation (TOV) and separated into their diffuse and direct fractions, used as upper boundary conditions. The radiance field is treated as approximately isotropic, but its zenithal distribution can be varied by the so-called diffusivity factor, which allows together with the incident EFDs at TOV to take the sky conditions above the canopy into account. Simulations of the canopy reflectance and transmittance are performed in the UV/VIS as function of the solar zenith angle and the ratio of the direct and diffuse sky light above the canopy representing clear and overcast sky conditions. These computations demonstrate that the radiative transfer in vegetation is significantly influenced by this ratio and the LND of the leaves. / Diese Arbeit berichtet ¨uber den Zweistrom-Strahlungstransfer eines horizontal homogenen und trüben Vegetationsmediums, wobei bi-Lambertsche Streuung an als eben betrachteten Modellblätter angenommen wird. Die abgeleiteten Zweistrom-Strahlungstransportgleichungen werden analytisch gelöst für verschiedene Blattarchitekturen, indem Blattnormalenverteilungsfunktionen (BNV) von rein vertikalen bis rein horizontale Bl¨atter ber¨ucksichtigt werden. Diese Transfermodelle werden durch Strahlungsflussdichten angetrieben, die am Oberrand der Vegetation gegeben und in deren Direkt- und Diffusanteil aufgespalten sind, wobei letztere als obere Randbedingungen fungieren. Das Strahldichtefeld wird als nahezu isotrop angenommen, jedoch kann dessen Zenitwinkelabh¨angigkeit durch den sogenannten Diffusivit¨atsfaktor variiert werden, der es zusammen mit den am Oberrand einfallenden Strahlungsflussdichten erlaubt, unterschiedliche Bedingungen f¨ur das atmosph ¨arische Himmelslicht zu ber¨ucksichtigen. Es wurden Simulationen der Reflektanz und Transmittanz des Gesamtmediums im UV/VIS als Funktion des Sonnenzenitwinkels sowie des Verh¨altnisses des Direkt- und Diffuslichts durchgef¨uhrt, stellvertretend f¨ur klare Tage und bew¨olkte Situationen. Diese Berechnungen zeigen, dass der Strahlungstransfer in Vegetation deutlich von diesem Verh¨altnis sowie von der BNV der Bl¨atter abh¨angt.

The initial phases of the design process -- including interactions with stakeholders, ideation of concept candidates, and the selection of the best candidates --- have a large impact on the success of a project as a whole. Much of the value generated during these phases comes from the designers' exploration of the design space as they create concepts for the final solution. Unfortunately, an entire dimension of the design space is often ignored during the initial phases of the design process -- the tactics dimension. Engineers tend to emphasize the design of technology in their work, while paying less attention to how that technology is used. By adding tactics to technology as two dimensions of the design space and creating the Tech/Tac plot as a means for visualizing those dimensions, the designer's ability to visualize, understand, and explore an expanded design space is improved. In this paper, we introduce a deliberate design-space structure that can help teams generate and evaluate integrated Tech/Tac concepts. The structure improves concept exploration during the early phases of the design process by harnessing the information provided by a two-dimensional, structured design space. This design space is represented here as a vector space with a basis of technology and tactics. Also presented are definitions and principles that facilitate the use of the technology-tactics framework to represent the design space in various useful ways. Six tests were carried out during this research to develop and evaluate the structure. The final instantiation of the concepts presented in this paper has been shown to be meaningful to design teams during ideation.