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L’évaluation des formations géologiques consiste en l’analyse et la synthèse de données de différentes sources, de différentes échelles (microscopique à kilométrique) et acquises à des dates très variables. Le processus conventionnel de caractérisation des formations relève alors de l’interprétation physique spécialisée de chacune de ces sources de données et leur mise en cohérence par des processus de synthèse essentiellement d’ordre statistique (corrélation, apprentissage, up-scaling…). Il s’avère cependant qu’une source de données présente un caractère central : les diagraphies. Ces mesures physiques de différentes natures (nucléaires, acoustiques, électromagnétiques…) sont réalisées le long de la paroi d’un puits à l’aide de différentes sondes. Elles sont sensibles aux propriétés in situ des roches, et ce, sur une gamme d’échelle centimétrique à métrique intermédiaire aux carottes et données de test de production. De par leur profondeur d’investigation, les données diagraphiques sont particulièrement sensibles au phénomène d’invasion de boue se produisant lors du forage dans l’abord puits. Traditionnellement, l’invasion est modélisée de façon frustre au moment de l’interprétation diagraphiques par un simple effet piston. Ce modèle simple permet d’honorer le bilan de volume mais ne prend aucunement en compte la physique réelle d’invasion et prive, de fait, les diagraphies de toute portée dynamique. Des essais de modélisation de l’historique d’invasion couplés aux données diagraphiques ont déjà été élaborés par différents laboratoires et une abondante littérature sur le sujet est disponible. Les limitations majeures de ces approches résident dans le caractère sous déterminé des problèmes inverses issus de ces modèles physiques et dans le fait que la donnée diagraphique est réalisée en général sur un intervalle de temps inadaptée au regard du développement de l’invasion. Nous proposons une approche différente qui s’attèle non pas à décrire la physique de l’écoulement mais celle de l’équilibre radial des fluides dans le domaine envahi lorsque les diagraphies sont acquises. Nous montrons qu’en introduisant quelques contraintes pétrophysiques supplémentaires, il est possible d’inverser efficacement la distribution des propriétés dynamiques pour chaque faciès géologique. L’inversion prend en compte le phénomène d’invasion radial dans la zone à eau ainsi que l’équilibre capillaire vertical caractérisant le profil de saturation dans le réservoir pour chaque facies. A chaque profondeur du puits, sont ainsi obtenues perméabilités, pressions capillaires et facteurs de cimentation avec leurs incertitudes ainsi que les lois pétrophysiques propres à chaque faciès. Cette méthode a été appliquée à deux puits réels. En guise de validation, les résultats d’inversion ont été comparés aux mesures laboratoire faites sur carotte. De plus, les perméabilités inversées ont été comparées aux transitoires de pression de mini-tests. La cohérence des résultats montre que, d’une part, les hypothèses de base du modèle sont validées et que, d’autre part, l’approche fournit une estimation fiable de grandeurs dynamiques à toute échelle pour chaque faciès réservoir, et ce, dès l’acquisition des données diagraphiques. L’approche d’inversion proposée a permis de lever une limitation majeure des précédentes tentatives de prédiction des propriétés dynamiques par les diagraphies en reconsidérant la problématique non pas sous l’angle d’une modélisation phénoménologique exacte mais en l’abordant de manière globale à l’échelle d’une chaîne d’étude complète. Cette approche permet de fait une mise en cohérence très précoce des données, d’identifier les faciès d’intérêt et de qualifier les besoins véritables en données. Cet outil s’avère très puissant pour qualifier et caractériser les hétérogénéités pétrophysiques des formations et aider ainsi à résoudre le problème de mise à l’échelle des grandeurs dynamiques / The current geological formation evaluation process is built on a workflow using data from differentsources, different scales (microscopic to kilometric) and acquired at different times. Theconventional process of formation evaluation belongs to the dedicated study of each of thesesource of data and their reconciliation through a synthesis step, often based on statisticalconsideration (correlation, learning, up-scaling …). It turns out that there exists a source of datawhich is of considerable importance: logs. These physical measurements of different nature(nuclear, acoustic, electro-magnetic…) are acquired all across the well thanks to multiple probes.They are sensitive to the in situ properties of the rock on an intermediate scale between core dataand well tests (from centimeters to several meters). Because of their depth of investigation, logsare particularly sensitive to the mud filtrate invasion, a phenomenon which occurs during thedrilling in the near well-bore environment. The invasion is conventionally modeled in a rough waywith a piston effect hypothesis. This simple model allows to ensure the volume balance but doesnot take into account the physical processes of the invasion and thus prevent any estimation ofdynamic properties from log interpretation. Several attempts of simulating the complete history ofinvasion have been made by different laboratories in the past, and a rich literature is available onthis topic. The major pitfalls of these approaches come from the under-determination of theinverse problems derived from such models. Furthermore, logs are generally made in a time lapsewhich does not allow to fully characterize the process of invasion. We propose a differentapproach which does not fully describe the physics of the invasion but considers that a radialequilibrium has been reached between the fluids in the invaded zone when logs are acquired. Weshow that it is possible to efficiently invert the distribution of dynamical properties for eachgeological facies by adding some petrophysical constraints. The inversion takes into account thephenomenon of radial invasion in the water zone and the vertical capillary equilibrium describingthe water saturation profile in the reservoir for each facies. At each depth, permeabilities, capillarypressures and cementation factors are thus obtained, along with their uncertainties and thepetrophysical laws specific to each facies. This method has been applied to two wells. Weobtained good results when comparing inverted parameters to the measurements made on coresamples in laboratory. Furthermore, inverted permeabilities have also been compared topermeabilities derived from mini-tests. The consistency of the results shows that, on the one hand,the hypothesis behind our model are valid and, on the other hand, this approach can provide areliable estimation of dynamical parameters at different scales for each reservoir facies as soon asthe logs are acquired. The proposed approach allows to overcome a major limitation of theprevious attempts of the dynamical properties estimation from log interpretation. It allows areconciliation of different data and a facies recognition at an early stage of interpretation, and canindicate the real contribution of each source of data. The technique can even help in identifying theformation heterogeneities and for the petrophysical upscaling.

Data Logging is the main activity to be considered in maintaining a server or database in working condition without any errors or failures. Data collection can be automatic, so, no human presence is necessary. To store the data of logs for many days and visualizing became a huge problem in recent days. Coming to node SGSN-MME, which is the main component of the GPRS network, which handles all packet switched data within the mobile operator's network. A lot of log data is generated and stored in file systems on the redundant File Server Boards in SGSN-MME node. The evolution of the SGSN-MME is taking it from dedicated, purpose-built, hardware into virtual machines in the Cloud, where virtual file server boards fit very badly. The purpose of this thesis is to give a better way to store the log data and add visualization using the ELK stack concept. Fetching useful information from logs is one of the most important part of this stack and is being done in Logstash using its grok filters and a set of input, filter and output plug-ins which helps to scale this functionality for taking various kinds of inputs ( file,TCP, UDP, gemfire, stdin, UNIX, web sockets and even IRC and twitter and many more) , filter them using (groks,grep,date filters etc.)and finally write output to ElasticSearch. The Research Methodology involved in carrying out this thesis work is a Qualitative approach. A study is carried using the ELK concept with respect to Legacy approach in Ericsson company. A suitable approach and the better possible solution is given to the vSGSN-MME node to store the log data. Also to provide the performance and uses multiple users of input providers and provides the analysis of the graphs from the results and analysis. To perform the tests accurately, readings are taken in defined failure scenarios. From the test cases, a plot is provided on the CPU load in vSGSN-MME which easily gives the suitable and best promising way.

Eating disorders have the highest mortality rate of all mental illnesses. Currently, web-logs are hosts to thousands of pro-ana (short for pro-anorexia) blogring participants, joining together with a common claim that eating disorders are "lifestyles not illnesses." This study explored participation motives among pro-ana blogring participants, relationships to individual psycho-social factors, and to unique web-log features. Results from the cross-sectional online survey suggest three main participation motives among blogring participants (community, obtaining social/ emotional support, and ego-protection). Results also indicate individual factors such as; social support satisfaction, drive-for-thinness, and BMI were related to blogger motives in a various diverse ways. Analyses of the findings from the present study reflect the self-disclosive nature of the blogging process. The results have several implications for eating disorder, computer-mediated communication, internet social support, and blog/blogring research.

In recent years, due to flourishing growth of internet, every protocol is approaching standardization and scientific applications are becoming full-grown everyday. Moreover, with the aid of internet educational resource and multimedia instruments, web-based instruction system has been enabled to build an internet learning environment which is different from traditional one. Teaching on the internet can not only overcome the limit of time and space, but also let students become more autonomous in their time and location of learning. Furthermore, all learning activities can be recorded in Web Logs automatically under the circumstances of not interfering with students when browsing learning material, interactive discussion, or team work learning. Because the Web Logs may also contain huge amount of non-educational meaning informations, teachers cannot directly use the Web Logs to observe student learning behaviors and to check learning situations. Many analytical instruments of Web Logs cannot either enable teachers to see educational meaning from Web Logs or carry out learning portfolio analysis. This research is to provide analysis of student Web Logs easily. Therefore, OLAP, and graphic data analytical techniques are used to design a visual learning portfolio analysis system. This system provides teachers to analyze the procedures of learning activities from different perspectives and graphic methods in order to understand the participatory extent of students toward learning activities. Besides, the evidence of students participate in learning activities will be surfaced, which can help teachers to evaluate the learning results effectively.

>Magister Scientiae - MSc / The evaluation of petroleum reservoirs has shifted from single approach to an integrated approach. The integration, analysis and understanding of all available data from the well bore and creating property models is an exceptional way to characterize a reservoir. Formulating, implementing, and demonstrating the applicability of the joint inversion of seismic and well-bore related observations, and the use of information about the relationship between porosity and permeability as the key parameters for identifying the rock types and reservoir characterization is a vital approach in this study. Correlating well and seismic data, potential reservoirs can be delineated and important horizons (markers) can be pointed out to better characterize the reservoir. This thesis aims to evaluate the potential petroleum reservoirs of the Wells K-A1, K-A2, K-A3 and K-H1 of the Shungu Shungu field in the Orange Basin through the integration and comparison of results from core analysis, wireline logs and seismic and attempt to produce a good reservoir model and by additionally utilizing Petrophysics and seismic and trying to better understand why the area has dry wells. Different rock types that comprise reservoir and non reservoirs are identified in the study and five Facie types are distinguished. Tight, fine grained sandstones with low porosity values ranging from 3% - 6% where dominant in the targeted sandstone layers. Porosity values ranging from 11% - 18% where identified in the massive sandstone lithologies which where hosted by Well’s K-A2 and K-A3. Low permeability values reaching 0.1mD exist throughout the study area. Areas with high porosity also host high water saturation values ranging from 70 – 84%. An improvement in the porosity values at deeper zones (3700m -3725m) and is apparent. Poroperm plots exhibit quartz cemented sandstones and density with neutron plot suggest that the sandstones in the area contain quarts and dolomite mineralization.Well K-A3, consist of a cluster by quartzitic sandstone, meaning there is a large amount of sandstone present. There are apparent high porosity values around the sandstone. What is apparent from this plot is that there are many clusters that are scattered outside the chart. This could suggest some gas expulsions within this Well. Sandstones within the 14B2t1 to 14At1 interval are less developed in the vicinity covered by well K-A2 than at the K-A1 well location. The main targeted sandstones belong to the lower cretaceous and lie just below 13At1. The four wells drilled in this area are dry wells. The areas/blocks surrounding this area have shown to possess encouraging gas shows and a comparative study could reveal better answers. At deeper zones of the well at an interval of 5350m -5750m, there are more developed sandstones with good porosity values. The volume of shale is low and so is the water saturation. The main target sandstones in the study area are the Lower Cretaceous sandstones which are at an interval 13At1. These sandstones are not well developed but from the property model of the target surface it can be seen that the porosity values are much more improved than the average values applied on all the zones on the 3D grid.

>Magister Scientiae - MSc / The fracture porosity and permeability of the Beaufort Seam 1 (BS1) and Ecca coal seams of the Waterberg Basin have been comprehensively characterised with the aid of geophysical wire‐line logs. The main aim of the thesis was to estimate the porosity and permeability of the coal seams using down‐hole wire‐line data; comparing results from injection falloff test to establish the validity of the technique as a fast an effective method. The study area is the largely under explored Karoo‐aged, fault bounded Waterberg basin Located in the Limpopo Province of South Africa. The study employed mainly the density and dual lateral resistivity logging data (Las format) from eight wells (WTB45, WTB48, WTB56, WTB58, WTB62, WTB65, WTB70 and WTB72). Density logging data was used for coal identification and fracture porosity estimation while fracture permeability was estimated from dual lateralog resistivity data. Analysis of fracture porosity required coal cementation indices and fracture width as an input parameter. These were estimated with the aid of water pump out test data, coal quality and gas analysis data provided by Anglo Coal in addition to the above mention logs. The collection of sheet coal model was used to represent anisotropic coal reservoirs with non‐uniform fracture system was used to represent these coals. The mathematical formulas used to estimate both fracture porosity and permeability took into account the above coal model. The theoretical formulas are a modification from both Darcy’s equation and Archie’s equations. The coal seams were encountered at depths ranging from 198m to 385m in the wells and were marked by low density and very high resistivity. From the estimated results the coal reservoirs are characterised by high cementation indices ranging from 0.82 to 2.42, very low fracture porosity and low fracture permeability. Estimated results show that coal reservoir fracture porosity ranged from 0.0002% to 0.33% for both BS1 and Ecca seams. Estimated results also show that coal reservoir permeability ranged from 0.0045mD to 6.05mD in the BS1 formation and from 0.01 to 0.107mD in the Ecca. Results when compared with those of injection falloff test shows that the estimated permeability is slightly lower as expected since the model did not account for coal anisopropy. The fracture permeability was found to decrease with increase in vitrinite content, coal rank, coal burial depth and increases with increase in inertinite content. On a basinal scale the model estimated permeability was found to increase slightly from the east to the west of the basin. The porosity decreases with increase cementation index for deeper coal seams and increases with increase cementation index for shallower coal seams.

Modern IT infrastructures are constructed by large scale computing systems and administered by IT service providers. Manually maintaining such large computing systems is costly and inefficient. Service providers often seek automatic or semi-automatic methodologies of detecting and resolving system issues to improve their service quality and efficiency. This dissertation investigates several data-driven approaches for assisting service providers in achieving this goal. The detailed problems studied by these approaches can be categorized into the three aspects in the service workflow: 1) preprocessing raw textual system logs to structural events; 2) refining monitoring configurations for eliminating false positives and false negatives; 3) improving the efficiency of system diagnosis on detected alerts. Solving these problems usually requires a huge amount of domain knowledge about the particular computing systems. The approaches investigated by this dissertation are developed based on event mining algorithms, which are able to automatically derive part of that knowledge from the historical system logs, events and tickets. In particular, two textual clustering algorithms are developed for converting raw textual logs into system events. For refining the monitoring configuration, a rule based alert prediction algorithm is proposed for eliminating false alerts (false positives) without losing any real alert and a textual classification method is applied to identify the missing alerts (false negatives) from manual incident tickets. For system diagnosis, this dissertation presents an efficient algorithm for discovering the temporal dependencies between system events with corresponding time lags, which can help the administrators to determine the redundancies of deployed monitoring situations and dependencies of system components. To improve the efficiency of incident ticket resolving, several KNN-based algorithms that recommend relevant historical tickets with resolutions for incoming tickets are investigated. Finally, this dissertation offers a novel algorithm for searching similar textual event segments over large system logs that assists administrators to locate similar system behaviors in the logs. Extensive empirical evaluation on system logs, events and tickets from real IT infrastructures demonstrates the effectiveness and efficiency of the proposed approaches.

>Magister Scientiae - MSc / The Bredasdorp Basin is one of the largest hydrocarbon producing blocks within Southern Africa. The E-M field is situated approximate 50 km west from the FA platform and was brought into commission due to the potential hydrocarbons it may hold. If this field is brought up to full producing capability it will extend the lifespan of the refining station in Mosselbay, situated on the south coast of South Africa, by approximately 8-10 years. This study is focused in block 9 off shore western part of the Bredasdorp Basin in the main Outeniqua Basin South Africa. Cretaceous Sandstone reservoirs are commonly heterogeneous consequently they may require special methods and techniques for description and evaluation. Reservoir characterization is the study of the reservoir rocks, their petrophysical properties, the fluids they contain or the manner in which they influence the movement of fluids in the subsurface. The main goal of the research is to assess the potentials of hydrocarbons in Cretaceous sediments in the Bredasdorp Basin through the integration and comparison of results from core analysis, production data and petrography studies for the evaluation and correction of key petrophysical parameters from wireline logs which could be used to generate an effective reservoir model for wells (E-BB1, E-BD2, EA01) in the Bredasdorp Basin. Porosity and permeability relationships, wire-line log data have been examined and analysed to determine how the porosity and permeability influence reservoir quality which further influences the potential of hydrocarbon accumulation in the reservoirs. The reservoir sandstone is composed mainly of fine to medium grained Sandstones with intercalation of finger stringers of Siltstone and Shale. In carrying out this research the samples are used to characterize reservoir zones through core observation, description and analyses and compare the findings with electronic data obtained from Petroleum Agency of South Africa (PASA). Secondary data obtained from (PASA) was analysed using softwares such as Interactive Petrophysics (IP), Ms Word, Ms excel and Surfer. Wireline logs of selected wells (E-BB1, E-BD2, E-A01) were generated, analysed and correlated. Surfer software also used to digitize maps of project area, porosity and permeability plotted using IP. Formation of the Bredasdorp Basin and it surrounding basins during the Gondwana breakup. The Bredasdorp Basin consists mainly of tilting half graben structures that formed through rifting with the break-up of Gondwanaland. The model also revealed that these faults segregate the reservoir which explains the pressure loss within the block. The production well was drilled, confining pressure relieved and pressure dropped hence production decreases. The age, transportation, deposition and thermal history of sediment in the basin, all plays a vital role in the type of hydrocarbon formation. Structural features such as faults, pore spaces determines the presence of a hydrocarbon in the reservoir. Traps could be stratigraphic or structural which helps prevent the migration of hydrocarbons from the source rock to reservoir rock or from reservoir rock to the surface over a period of time. The textural aspects included the identification of grain sizes, sorting and grain shapes. The diagenetic history, constructed from the results of the reservoir quality study revealed that there were several stages involved in the diagenetic process. It illustrated several phases of cementation with quartz, carbonate and dolomite with dissolution of feldspar. A potentially good reservoir interval was identified from the data and was characterized by several heterogeneous zones. Identifying reservoir zones was highly beneficial during devising recovery techniques for production of hydrocarbons. Secondary recovery methods have thus been devised to enhance well performance. As recommendation, additional wells are required to appraise the E-M structure and determine to what extent the cement present in the basin has affected fluid flow as well as the degree of sedimentation that could impede fluid flow. There are areas still containing untapped resources thus the recommendation for extra wells. This research may well be reviewed with more data input from PetroSA (wells, seismic and production data) for additional studies, predominantly with respect to reservoir modelling and flow simulation. Based on the findings of this research, summary of calculated Net Pay shows that in well E-BB1, reservoir (1) is at depth 2841.5m – 2874.9m has a Gross Thickness of 33.40m, Net Pay of 29.72 and Pay Summary of 29.57 and reservoir (2) has depth of 2888.1m – 2910.5m, Gross Thickness of 22.40m, Net Pay of 19.92m and Pay summary of 1.48m. Well E-AO1 has depth from 2669.5m – 2684.5m and Gross Thickness of 15.00m and has Net Pay of 10.37m and Pay Summary of 10.37m. Based on the values obtained from the data analysed the above two wells displays high potential of hydrocarbon present in the reservoirs. Meanwhile well E-BD2 has depth from 2576.2m – 2602.5m and has Gross Thickness of 350.00m, Net Pay of 28.96m and Pay Summary of 4.57 hence from data analysis this reservoir displays poor values which is an indication of poor hydrocarbon potentials.

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