The collapse of a mine pillar is a catastrophic event with great consequences for a mining operation. These events are not uncommon, and have been reported to produce air blasts able to knock down, seriously injury or kill miners; cause cascade pillar failures which involve the collapse of neighboring pillars; produce surface subsidence; and sterilize valuable reserves. In spite of the low probability of occurrence for a pillar collapse in comparison to other ground control instability issues, these consequences make these events high risk. Therefore, the design of these structures should be considered from a risk perspective rather than from a factor-of-safety deterministic approach, as it has been traditionally done. Discontinuities are one of the main failure drivers in underground stone pillars. Regardless of this, traditional pillar strength equations do not consider the effect of these. Recently, the NIOSH pillar strength equation introduced a Large Discontinuity Factor that acknowledges the effect of discontinuities in pillar strength. However, this parameter only considers "averaged" parameters in a deterministic way, failing to account for the spatial variability of fracture networks. This work presents a risk-based pillar design framework that enables to characterize the effect of discontinuities in pillar strength, as well as account for the possible range of stresses that will be acting on pillars. The proposed method was evaluated in an underground dipping stone mine. Discontinuities were characterized by integrating Laser Scanning and virtual discontinuity mapping. Information obtained from the discontinuity mapping process was used to generate discrete fracture networks (DFNs) for each discontinuity set. The Discrete Element Modeling Software 3DEC was used along with the DFNs to simulate fractured rock pillars. Different fractured pillar strength modeling approaches were evaluated, and the most adequate in terms of pillar strength values, failure mechanisms representation, and processing times, was selected. The selected model was tested stochastically, and these results were used to characterize pillar strength variability due to the presence of discontinuities. Pillar stress distributions were estimated using an stochastic finite volume continuous numerical model that accounted for the dipping nature of the deposit and the case study mine design. A pillar probability of failure baseline was defined by contrasting resulting pillar strength and stress distributions using the reliability method. Results from this design framework provide additional decision-making tools to prevent pillar failure from the design stages by reducing the uncertainty. The proposed method enables the integration of pillar design into the risk analysis framework of the mining operation, ultimately improving safety by preventing future pillar collapses. / Doctor of Philosophy / Underground mining operations involve the removal of rock material from the ground. Engineers are required to design structural elements to ensure the stability of the openings as the material is extracted. These structural elements are known as pillars, and are usually carefully-designed regular chunks of rock left unmined. The pressures that the mined rock was carrying are shed to these pillars, which sizes and dimensions must provide enough strength to ensure the overall stability of the mine and avoid a collapse. Failure of mine pillars are events that have occurred, causing serious consequences such as injuring and killing mine workers, producing ground surface sinking affecting neighboring communities, and halting the regular mine operation. Due to the severity of the consequences of pillar collapses, these events are classified as high risk. Therefore, pillar design should be addressed from a perspective that estimates the likelihood of pillar failure given all possible hazards during their design process. The rock material that composes mine pillars present fractures and weakness planes that have an influence on pillar strength. Even though it has been widely demonstrated that these features have a direct impact on pillar strength, most of the commonly used pillar design methods fail to consider such effect, producing uncertainty about the possible range of values for the actual strength of the pillars. This work introduces a pillar design framework that enables to characterize the effect of discontinuities in pillar strength, as well as account for the possible range of stresses that will be acting on pillars. The proposed method was evaluated in an underground inclined stone mine. Laser scanning was used to map and characterize rock fractures. Fracturing information was used to generate virtual three-dimensional fracture models referred to as discrete fracture networks (DFNs). A computational mechanical model of the mine pillar was done using the software 3DEC to evaluate the compressive strength of the fractured pillar. Multiple fracturing scenarios were tested and distributions of possible pillar strengths were estimated from these tests. An additional computational model to estimate the distribution of the stresses in the pillar was performed considering the mine designs and geological conditions. Results from both analyses allowed to estimate a pillar probability of failure baseline. This design framework provides additional decision-making tools to prevent pillar failure from the design stages by reducing uncertainty. The proposed method enables the integration of pillar design into the risk analysis framework of the mining operation, ultimately improving safety by preventing future pillar collapses.

There are two major design problems for upper seam longwall gateroads operating in a multi-seam environment. The first is to determine the location, magnitude and duration of stress transferred from lower seam mines; and the second is to predict the effect of stress transferred from lower seam mines on opening stability. To solve these problems for both longwall and room-and-pillar mines, case study data were collected and analyzed to develop empirical models predicting upper seam damage created by mining activities in the lower seam. Analysis showed vertical movement in the upper seam and roof CMRR (Coal Mine Roof Rating) to be the controlling factors in damage prediction and, therefore, gateroad planning and design. The relationship between the predicted damage rating and the gateroad stability was established and quantified. To simplify the application of design procedures developed for longwall gateroad systems, the criteria were incorporated in a Windows-based, multi-interface software , UGLY (Upperseam Gateroad Longwall Stability). The programming language was Visual Basic, and the program's design capabilities were validated and demonstrated using case study data. / Master of Science

Underground coal mine ground control persists as a unique challenge in rock mass engineering. Fall of roof and rib continue to present a hazard to underground personnel. Stability of underground openings is a prerequisite for successful underground coal mine workings. An adaptation of a civil engineering design standard for analyzing the stability of underground excavations for mining geometries is given here. The ground response curve--developed over seventy years ago for assessing tunnel stability--has significant implications for the design of underground excavations, but has seen little use in complex mining applications. The interaction between the small scale (pillar stress-strain) and the large scale (ground response curve) is studied. Further analysis between these two length scales is conducted to estimate the stress on pillars in a room-and-pillar coal mine. These studies are performed in FLAC3D by implementing a two-scale, two-step approach. This two-scale approach allows for the interaction between the small, pillar scale and the large, panel scale to be studied in a computationally efficient manner. / Ph. D.

This thesis analyzes the current status of pension funds in the Czech Republic, the subsequent transformation of the pension companies and the situation after the introduction of the second pillar. It examined the merits of a new pillar in the small benefit to future participants and the impact on the state budget. The main result is to propose a solution that would be more beneficial for participants and fulfill the requirement for a balanced fiscal policy. The presented work uses descriptive and comparative analysis of the current position of pension funds. Description of the reform of the pension system is based on legislative analysis and secondary analysis of published literature. In the design of solutions are used in mathematical statistical methods, comparative analysis and questionnaire method.

Digitalisation and globalisation have significantly impacted daily life, including taxation, resulting in benefits and disadvantages. One major issue lies in the global context, where tax evasion and erosion have become prevalent issues. To address these challenges, the International Organization for Economic Co-operation and Development (OECD) has introduced a new set of rules known as Pillar Two. These rules aim to address the competition for attracting investors through a “race to the bottom” in tax rates by establishing a standardised Global Minimum Tax (GMT) rate of 15% to be applied to economic activities across jurisdictions. Thailand has recently announced its intention to incorporate these rules into domestic tax laws. Consequently, this thesis examined the implications of implementing Pillar Two on allocating taxing rights within the national legislative framework. The research utilised the dogmatic legal method to identify and analyse the current Thai tax system, Pillar Two model rules, and perspectives on implementation. The findings illustrated the most beneficial approach to allocating taxing rights to Thailand.

The diploma thesis deals with the pension reform and the pension system in the Czech Republic. The paper explains fundamental terms in the field and explains their function. The main aim of the thesis is a definition and risk analysis of individual parts of the pension system. The secondary aim is guidance how to use each of the parts of the system.

La préparation de briques élémentaires de pillar[5]arènes « clickables » nous ont permis de construire des édifices moléculaires complexes, en greffant différents groupements fonctionnels autour du coeur macrocyclique. Dans ce contexte, des nouveaux dérivés du pillar[5]arène présentant des propriétés cristaux-liquides ont été synthétisés en greffant du p-dodecyloxybenzoate ou encore des dendrons de type percec. D’autres part, des dérivés pillarèniques portant des unités de porphyrines ont été préparés à partir du squelette « clickable » pillar[5]arène et de porphyrines de Zinc portant des fonctions alcynes vrai. Les études de ce système par RMN du proton à des températures variables ont permis de mettre en évidence un équilibre conformationnel dynamique conduisant au repliement des molécules. Ceci a été expliqué par une complexation intramoléculaire des porphyrines de Zinc par les groupements 1,2,3-triazole. Finalement un support « clickable » detype [2]rotaxane comportant une porphyrine base libre comme bouchon, a été préparé et ensuite fonctionnalisé par dix porphyrines de Zinc permettant l’obtention d’un dispositif supramoléculaire photoactif. / Clickable pillar[5]arene building blocks have been used for the efficient grafting of peripheral subunits onto the macrocyclic core. New liquid-crystalline pillar[5]arene derivatives have been prepared by grafting either p-dodecyloxybenzoate groups or percec-type dendrons on the macrocyclic scaffold. On the other hand, pillar[5]arene derivatives bearing peripheral porphyrin subunits have been efficiently prepared from the clickable pillar[5]arene building block and Zn(II)-porphyrin derivatives bearing a terminal alkyne function. Owing to an intramolecular complexation of the peripheral Zn(II)-porphyrin moieties by 1,2,3-triazole subunits, an original dynamic conformational equilibrium leading to a folding of the molecules has been evidenced by variable temperature 1H NMR studies. Finally, a clickable [2]rotaxane scaffold incorporating a free-base porphyrin stopper has been prepared and functionalized with ten peripheral Zn(II)-porphyrin moieties to afford a sophisticated photoactive supramolecular device.

Le travail de doctorat réalisé s'attache à étudier les nouveaux types d'interconnexions comme les TSV (Through Silicon Via), les lignes de redistribution (RDL) et les piliers de cuivre (Cu-Pillar) présentes dans le domaine de l'intégration 3D en microélectronique avancée, par exemple pour des applications de type « imager » où une puce « capteur optique » est empilée sur une puce « processeur ». Afin de comprendre et quantifier le comportement électrique de ces nouveaux composants d'interconnexion, une première problématique de la thèse s'articulait autour de la caractérisation électrique, sur une très large bande de fréquence (10 MHz - 60 GHz) de ces éléments, enfouis dans leurs environnements complexes d'intégration, en particulier avec l'analyse de l'impact des pertes dans les substrats de silicium dans une gamme de conductivités allant de très faible (0 S/m) à très forte (10 000 S/m). Par la suite, une nouvelle problématique prend alors naissance sur la nécessité de développer des modèles mathématiques permettant de prédire le comportement électrique des interconnexions 3D. Les modèles électriques développés doivent tenir compte des pertes, des couplages ainsi que de certains phénomènes liés à la montée en fréquence (courants de Foucault) en fonction des caractéristiques matériaux, des dimensions et des architectures (haute à faible densité d'intégration). Enfin, à partir des modèles développés, une dernière partie propose une étude sur les stratégies de routage dans les empilements 3D de puces à partir d'une analyse sur l'intégrité de signaux. En opposant différents environnements, débit de signaux binaires ou dimensions des TSV et des RDL des conclusions émergent sur les stratégies à adopter pour améliorer les performances des circuits conçus en intégration 3D. / The aim of this doctoral work is to study the new kind of interconnections like TSV (Through Silicon Via), redistribution lines (RDL) and copper pillars used in 3D integration context in advanced microelectronic components. An example of 3D integration application could be an imager designed by staking an optical sensor chip upon a processor chip. In order to understand and quantify the electrical behaviour of these new interconnection components, the first issue was about electrical characterization in a very wide frequency band (10 MHz - 60 GHz) of these elements, buried in their complex environment, in particular with the analysis of the silicon substrate loss impact which can be found in a wide band of conductivities from very low (0 S/m) to very high (10 000 S/m). Subsequently, a second issue appears from the need to develop mathematical models to predict the electrical behavior of 3D interconnects. The developed models have to take into account losses, coupling effects and some phenomena appearing with the rise of frequency (eddy currents) according to material characteristics, dimensions and architecture (from high to low density of integration). Finally, based on developed models, the last part presents a study on routing strategies in the 3D stacking chip from the analysis of signal integrity. By contrasting various environments, binary signals flow or dimensions of TSV and RDL, conclusions emerge on the best strategies to use to improve performances of circuits designed in 3D integration.

Analogues aux cyclotrivératrilènes et aux calix[n]arènes, les pillar[n]arènes sont composés de n unités hydroquinoliques et reliés entre elles par un pont méthylénique en position para. Ces macrocycles ont été utilisés en tant que supports fonctionnalisables afin de préparer divers nanomatériaux. Dans ce contexte, la modification chimique du pont méthylénique a été réalisée sur le pillar[5]arène afin d’obtenir un nouveau site de fonctionnalisation, à ce jour jamais exploité. L’oxydation de cette position a permis dans un premier temps de réaliser une extension de cycle par une réaction de Colvin, afin d’obtenir un macrocycle portant une triple liaison tendue. Cette particularité a permis la réalisation de cycloaddition 1,3-dipolaire de Huisgen ou chimie click sans utilisation de cuivre(I), mais également l’obtention de produits de cycloadditions [2+2] par voie thermique normalement interdites. L’introduction d’un fullerène C60 sur ce pont méthylénique a également été réalisée sans déformation de la cavité. C’est pourquoi dans un deuxième temps des [2]rotaxanes photoactifs ont pu être élaborés à partir de ce fulléropillar[5]arène. Dans un dernier temps, une nouvelle méthode de préparation des [2]rotaxanes a été développée. Par échange de bouchons activés, divers [2]rotaxanes ont pu être synthétisés, sans être limités par la nature des bouchons souhaités. A partir de cette méthode de préparation, des cristaux liquides ont pu être obtenus en substituant ces bouchons activés par des bouchons portants des groupements post-fonctionnalisables, puis en greffant des groupements cyanobiphényles. / Analogues of cyclotriveratrylenes and calix[n]arenes, pillar[n]arenes are composed of 1,4-disubstituted hydroquinone subunits linked by methylene bridges in their para positions. This macrocyclic core has been used as a compact scaffold for the preparation of nanomaterials. In this context, the chemical modification of the methylene bridge has been achieved to further functionalize the core in a way never explored so far. Firstly, oxidation of this position followed by Colvin reaction generated a strained triple bond in the macrocyclic scaffold. This particularity allowed the introduction of functional groups under copper free Huisgen 1,3-dipolar cycloadditions as well as by thermal [2+2] cycloadditions normally prohibited. Insertion of [60]fullerene on the methylene bridge has been also carried out. In a second time, photoactive [2]rotaxanes have been obtained from this fulleropillar[5]arene. Finally, a new methodology for the preparation of [2]rotaxanes has been developed. By exchange of activated stoppers, various [2]rotaxanes were thus obtained and this method is not limited by the nature of the stopper. This methodology has been used to prepare new liquid crystalline rotaxane derivatives by introduction of clickable stoppers followed by the grafting of dendritic mesogenic subunits.

Master thesis provides an overview of demographic development and its relations to the sustainability of the pension systems. The theoretical part of the thesis focuses on the description of demographical processes and its main characteristics since the year 1989 and prognoses of its future development in Czech Republic. Later on, the theoretical knowledge gained in the first part is interconnected with the description of the pension system, as defined in Czech Republic and as valid since 1st of January, 2013. In practical part of the thesis the main focus is given to the calculations of sustainability of the pension system. The calculations are performed at the model situation, based at the pension system as defined in Czech Republic, but adjusted for some simplifying facts and premises. The calculations are provided for few different situations, when the revenues and expenses of the first pillar of the pension system are calculated. Based on the development of revenues and expenses, the percentage of people, that are supposed to enter the second, fully funded, pillar is calculated. The percentage is calculated in situation when the revenues are equal to the expenses and therefore the PAYG part of the pension system is sustainable in the long run.