Miracle-dz/UniFAR-FTUs huggingface dataset:
Assessment of Data-Driven Ensemble Methods for Conserving Wellbore Stability in Deviated Wells

Accurate estimation of mud weight (MW) helps to conserve wellbore stability in real-time drilling operations. Determination of proper MW requires a correct understanding of the stress field, natural fractures, pore pressure, rock strength, borehole trajectories, etc. It is a problematic task especially in, highly inclined wells, deviated wells, and near salt formations due to uneven variations in wellbore stresses. Proper MWs are difficult to apply at target depths of the unstable formations because of uncertainties existing inside the wellbore. There are no reliable tools or techniques available that can precisely determine the optimum value of MW. This paper proposes a novel and more convenient approach to estimate the safe MW for deviated wells using surface measured data. In this study, Bagging and Random forest ensembles have been utilized to model the relationship between sensors measured variables and MW. The proposed framework has been trained and tested on real-time Norwegian post-drilling data. Artificial neural networks (ANNs) and support vector regression (SVR) have also been utilized in this study for comparison purposes. The analysis of prediction results clearly reveals that Random forest ensemble has acquired the highest coefficient of correlation and minimum estimation errors. The performance of Ensemble methods is found to be superior to the ANNs and SVR models. The proposed approach can be useful for the determination of MW required at different depths of reservoir formation and maintaining the wellbore stability during real-time operations.
Investigation of CO2 Sequestration for the Assessment of the Impact on Resource Storage with Co-production of Brine

Investigation of CO2 Sequestration for the Assessment of the Impact on Resource Storage with Co-production of Brine Mohammad Junaid Ashfaq In order to reduce Green House Gases, Carbon-dioxide (CO2) storage in deep saline aquifers is a viable commercial application for minimizing emissions. It is important to understand surface area needed to predict large scale CO2 storage while fully utilizing injection capacity. This study presents results from varying Injection pressure and well spacing to find minimal-effective well spacing required to store CO2. The study shows pressure management to manipulate hydrodynamic behavior of CO2 in saline formations system. In conjunction, understanding the interplay of CO2 dissolution, buoyancy flow, and capillary forces in regulating the behavior of the injected CO2 plume are important. Pressure manipulated by changing injection pressure with selected brine co-production, a technique known as CO2 sequestration. A 3-D reservoir model has been utilized to model CO2 sequestration behavior in a compositional simulator, CMG Builder. Mount Simon Sandstone (Cambrian) was selected as a ‘base case model’ for its recognition as an important deep saline reservoir with potential to serve as a largescale commercial CO2 storage field in the Midwestern United States. The study shows the impact of selected injection pressure on the utilization of brine aquifer. It is recommended to store CO2 with 4000 – 4500 psi injection pressure range for optimum storage and production conditions.
Reliable and Efficient Transmission in Wireless Body Area Networks

As one of the most practical and promising technologies, Wireless Boby Area Networks (WBANs) play a vital role in a variety of application areas, including ubiquitous healthcare, medical, sport, and entertainment. Meanwhile, the multiple application scenarios also result in stringent and various Quality of Service (QoS) requirements in terms of data rate, reliability, energy consumption, delay, etc. Besides, due to the complicated deployment environments and peculiar channel characteristics, the design of WBAN systems is more challenging than other Wireless Sensor Networks (WSNs). Among many transmission challenges in the context of WBANs, transmission reliability and energy efficiency are the two key challenges. This thesis focuses on investigating high transmission reliability and energy-efficient transmission schemes for WBAN systems. In order to capture the channel information variation in the real dynamic WBAN scenarios, we build a wearable wireless transceiver from easily-assembled commercial hardware modules. The measurements are conducted by test subjects wearing multiple wireless transceivers in dynamic scenarios. This thesis mainly focuses on two typical dynamic scenarios: walking and daily scenarios. Based on the channel gain datasets collected from these two scenarios, we analyze the on-body channel characteristics, including body shadowing effect, cross-correlation, autocorrelation, and transmission outage. Moreover, to improve the authenticity of our evaluation works, these channel datasets are imported into our simulation model to represent the channel variation. Motivated by the significant cross-correlation feature of on-body channels in the walking scenarios, we propose a novel cooperation-based Network Coding (NC) scheme, namely A3NC. In A3NC, we explore the combination of the Aggregative Allocation (AA) mechanism in the MAC (Medium Access Control) layer and the Analog Network Coding (ANC) technique in the physical (PHY) layer. By comprehensive theoretical analyses and comparisons from the perspectives of data rate, energy efficiency, and throughput balance, we explore the upper bounds of A3NC in terms of data rate and energy efficiency. Simulation results confirm that A3NC achieves a better performance in terms of data rate, energy efficiency, and throughput balance, compared to the conventional approaches. Extending from monotone walking scenarios to daily scenarios with mixed activities, we explore the Dynamic Slot Scheduling (DSS) method to improve the transmission reliability. DSS method optimizes the duration or order of time slots of different sensor
Snapshot multispectral imaging using a filter array.

A multispectral filter array (MSFA) is one solution for capturing a multispectral image (MSI) in a single shot at low cost. We introduce our optimization method of the spectral sensitivity of the MSFAs and demosaicking, and show a new prototype filter array for snapshot imaging based on a photonic crystal.
Environmental Drivers Shaping Physiological Flexibility of Plants in Saline Habitats from Shark Bay, Western Australia

The rapid desertification and salinization of arable soil makes it crucial to better understand adaptation mechanisms of plants in a continuously changing environment. Salinity and drought constitute selective forces in the adjustment of physiological processes in plants and are the major environmental factors determining plant productivity and distribution. Photosynthesis, the essential physiological process in all green plants, is severely affected by heat and salt stress (e.g. Ashaf and Harris, 2013). However, some plants possess flexibility in their C3 and C4 photosynthetic carbon fixation pathway and this increases their tolerance to elevated ambient salinity and temperature (Sage, 2004; Sage et al., 2012; Christin et al., 2013). Birridas, ancient landlocked saline lakes, distributed over Shark Bay of WA offer a unique model to test the influence of ambient salinity stress on plants. Across the Birridas there exists a soil salinity gradient and it is well known that salt-tolerant plant species that grow along stress gradients form characteristic zonation patterns. Furthermore, besides the high salinity, plants growing in the Birridas experience re-occurring anoxic stress resulting from the repeated flooding events. These environmental stresses act as filters shaping ecological and evolutionary adaptation of plants. Biotic interactions, notably with the root-associated microbiome (eukaryotes, bacteria and archaea) also may play an important role in the plant fitness and community assembly. The overall objective of this project is to investigate salt tolerant plants (halophytes) that grow along salinity gradients in Birridas to improve our understanding of the physiological adaptation mechanism of plants to stress. In particular we will attempt to understand the impact of salinity on the carbon and hydrogen utilization mechanisms of salt-tolerant plants. Compound specific stable carbon isotope analyses are conducted on plant lipids to elucidate the carbon fixation pathways of plants growing under elevated salinities. A preliminary stable carbon isotope analysis on some halophytes from the Shark Bay area suggests the ability to switch between C3 and C4 carbon assimilation pathways. Furthermore we investigate the impact of salinity on the lipid distribution of salt-tolerant plants. Analyses of plant leaf waxes revealed a species-specific n-alkane pattern along soil salinity gradients. Hydrogen isotopic ratios (δD) of leaf waxes will be investigated to explain to what extent the isotopic signal is driven by environmental factors and/or by plant species-specific fractionation. Rhizosphere microbiomes may also play a role to shape adaptation of halophytes, and eventually drive patterns of plant community assembly. Soil microbial communities will be examined from plant rhizosphere to see if microbial communities associated with plant roots change along a salinity gradient and have the metabolic potential to support plant growth under stress conditions.
GESTÃO AMBIENTAL E ZONEAMENTO DE ÁREAS ADJACENTES DO CAMPUS UNIVERSITÁRIO DA UFAM

Este estudo avaliou o Programa de Gestão Ambiental de áreas adjacentes ao Campus Arthur Virgílio Filho da Universidade Federal do Amazonas tendo como enfoque a Avenida Grande Circular. Como se sabe, o processo de caracterização e gestão ambiental de uma região é um processo que exige a confiabilidade de dados primários e secundários, uma vez que estas informações obtidas são importantes no processo de estudo em termos qualitativos e quantitativos de uma região. Para isso, dados oficiais e legais como o Instituto Brasileiro de Geografia e Estatística (IBGE), o Plano Diretor do Município, legislações municipais de ocupação do território foram usados.Dentro disso, realizou-se uma análise quanto ao processo de ocupação, presença de edificações, tipos de resíduos sólidos gerados, principais construções, fluxo de trânsito na região, presença de áreas verdes e arborização na região representada pelos limites da Avenida Grande Circular com o Campus UFAM. Assim, avaliou-se como o processo de ocupação nas áreas limítrofes da Universidade Federal do Amazonas ocorreu nas últimas décadas, observando-se que o crescimento ocorreu de forma desordenada e sem planejamento urbano.
Investigating the Impacts of Land Use/Cover Changes on the Stream Flows of Muga Watershed

Land use /land cover change have been responsible for altering the hydrological responses of watersheds leading to impact of the stream flows. Various water resource project planning and implementation will require knowledge of the extents of these changes on watershed hydrology. This study is mainly focusing on the investigation of the impacts of land use / land cover changes on the stream flow of Muga watershed which is located in the East Choke Mountains watersheds, Upper Blue Nile Basin, East Gojjam Zone, Amhara Region, Ethiopia. Soil and Water Assessment Tool (SWAT) model were used it investigate the impact of land cover change on the stream flow. For this study SWAT Simulation is used in identifying the most vulnerable sub basins to the stream flow and sediment load changes of Muga watershed. The model was calibrated and validated using historic Stream flow data. The model was calibrated using stream flow data from 1993 to1998, validated from 1999 to2002. The R2 and NSE values were used to examine model performance and the result indicates 0.81 and 0.87 to R2 and 0.80 and 0.86 to NSE during calibration and validation respectively. The result of this analysis indicated that the mean monthly stream flow for wet months had increased by 17.75 m3/s while the dry season decreased by 12.76m3/s during the 1995-2013 period due to the land use and land cover change. The highest annual surface runoff was attributed by sub basin 5 whereas sub basin 6 contributes the highest ground water respectively for 1995, 2003 and 2013 land cover maps. In terms of sediment yield, sub basin 1 contributes a maximum load for the study periods.
Variable-Frequency Control Strategy of Isolated Buck–Boost Converter

A control strategy with three control variables that contain switching frequency and two duty cycle ratios for an isolated buck–boost converter is proposed in this paper. The converter only operates in the discontinuous current mode (DCM) and the boundary current mode (BCM) in the whole voltage range and load range which can achieve an excellent soft-switching performance, a low energy circulation, and a high efficiency. On the basis of the operational principle and variables simplification, the optimal operating point that has a minimum clamped inductor peak current value is obtained. Under the variable-frequency control strategy, the converter characteristics are analyzed, such as the direct energy transfer time ratio, peak current value of the clamped inductor, and switching frequency. Moreover, the implementation of the closed-loop variable-frequency control strategy is given with three operational modes: variable-frequency BCM mode, constant-frequency BCM mode, and variable-frequency DCM mode. A 380-V 1-kW output prototype is fabricated, and the experimental results indicate that high efficiency over overall load range has been achieved under the variable-frequency control strategy due to the excellent soft-switching performance in the whole range. What is more, a smooth transition between three operational modes is achieved.
Influência da interação rio-aquífero sobre a distribuição vertical da meiofauna hiporreica

Entre os processos de autopurificação natural que ocorrem na zona hiporreica, estão os de aspecto biológico, onde os organismos da meiofauna desempenham importantes funções, favorecendo a melhoria da qualidade da água de recarga do aquífero subjacente ao rio. São diversos os fatores que influenciam a distribuição vertical da comunidade meiofaunística como o hidrodinamismo na massa hídrica superficial e a disponibilidade de matéria orgânica e oxigênio nas camadas mais profundas. Por isso, este artigo objetivou avaliar a influência destes dois fatores na distribuição vertical da meiofauna hiporreica em três pontos do rio Beberibe-PE. O hidrodinamismo foi considerado como resultado direto do regime pluviométrico e o fluxo vertical entre o rio e o aquífero foi analisado a partir de medições realizadas em três períodos pluviométricos distintos com auxílio do piezômetro diferencial. A análise da distribuição vertical da meiofauna foi realizada a partir do levantamento da abundância média em camadas de 2 cm até a profundidade de 10 cm. Foram contabilizados 4906 indivíduos pertencentes a 8 grupos taxonômicos. Os resultados mostraram que as camadas superficiais foram as mais abundantes. Entretanto, a diminuição desta abundância não se deu gradativamente com a profundidade, provavelmente por uma vazão maior do rio no período chuvoso e/ou por condições de rio influente. Apesar de que estes fatores não demonstraram um caráter completamente determinante sobre a distribuição vertical.
98 pA, 0.17 ppm/V, -72 dB@100 Hz voltage reference for Internet-of-Things systems

: This letter presents a pico-ampere level voltage reference with ultra-high performance of line regulation and power supply rejection ratio (PSRR) based on a self-regulation technique for Internet-of-Things (IoT) systems. Post-layout simulation results show that it achieves a minimum temperature coe ﬃ cient (TC) of 18.9 ppm / °C over the temperature range from 0 °C to 120 °C with a 1.2 V supply voltage. At 27 °C, its current consumption is 98 pA. The line regulation is 0.17 ppm / V over the supply voltage range from 1.2 V to 3.0 V and the PSRR is − 72 dB@100 Hz.
Next steps in describing possible effects of automated driving on traffic flow

Although at times traffic flow can be complicated to understand and predict, our current understanding is nevertheless pretty good and allows predictions of current and future situations to be made. However, this is about to change with the emergence of (partially) automated vehicles1on roads. This emergence will change the way people drive (speed and acceleration choices, following behaviour, lane change behaviour) and will change the dynamics present in traffic flow and with that the ability of traffic to move effectively. The first generation of partially automated vehicles is already on the road in the form of Adaptive Cruise Control (ACC) and Lane Keeping Assistance (LKA), as the so-called SAE level 1 vehicle automation (SAE 2014). Practical and technical tests are already widespread on higher levels of automation, with their mass-produced introduction expected in advance of 2020 (Merat et al. 2014). According to Shladover (2016) fully automated (SAE level 5) vehicles will not be here until 2075 at the earliest. At this point, no statement has been made on the point if these changes are going to be positive or negative. The reason for this is that there are too many uncertainties in relation to the effects that automated vehicles will have on traffic. Many enthusiasts have made incredible claims that automated vehicles will solve many of our traffic problems and can have an overwhelming positive effect on mobility, traffic flow and safety. However, these claims are rarely substantiated and are often based on questionable assumptions regarding the future. Furthermore, even if these claims are correct, they are applicable to a situation that lies many decades in the future, i.e. 100% penetration rate, and do not consider the route leading towards this future (the so called transition period). The main consensus within the traffic and mobility community is that traffic flow will initially worsen with the introduction of automated vehicles (Le Vine, Zolfaghari, and Polak 2015, SBD and HERE, 2016). This has a lot to do with conservative settings of automated vehicles, unfamiliarity with automated vehicles from both drivers and other road users, initial teething problems with the technology and a limited ability and penetration for cooperation between vehicles (Shladover, Su, and Lu 2012). Furthermore, there are predictions that traffic volume may eventually increase due to a steep uptake in automated vehicles (Wadud, MacKenzie, and Leiby 2016). However, again there is much uncertainty in relation to these statements, even if they are well substantiated Next steps in describing possible effects of automated driving on traffic flow. Available from: https://www.researchgate. net/publication/312377387_Next_steps_in_describing_possible_effects_of_automated_driving_on_traffic_flow? channel=doi&linkId=587c8ba108ae9a860fed444b&showFulltext=true [accessed Jul 18 2018].
Socio-economic value of the shark diving industry in Fiji

Authors: GMS Vianna1,2, JJ Meeuwig2, D Pannell3, H Sykes4 and MG Meekan1,* 1. Australian Institute of Marine Science, UWA Oceans Institute (M096) 35 Stirling Hwy, Crawley WA 6009. Australia 2. Centre for Marine Futures (M090), The University of Western Australia 35 Stirling Hwy, Crawley WA 6009. Australia 3. School of Agricultural and Resource Economics (M089), The University of Western Australia, 35 Stirling Hwy, Crawley WA 6009. Australia 4. Marine Ecology Consulting, Fiji
Directional Analysis of Stationary Point Processes

In this thesis we consider the directional analysis of stationary point processes. We focus on three non-parametric methods based on second order analysis which we have defined as Integral method, Ellipsoid method, and Projection method. We present the methods in a general setting and then focus on their application in the 2D and 3D case of a particular type of anisotropy mechanism called geometric anisotropy. We mainly consider regular point patterns motivated by our application to real 3D data coming from glaciology. Note that directional analysis of 3D data is not so prominent in the literature. We compare the performance of the methods, which depends on the relative parameters, in a simulation study both in 2D and 3D. Based on the results we give recommendations on how to choose the methods´ parameters in practice. We apply the directional analysis to the 3D data coming from glaciology, which consist in the locations of air-bubbles in polar ice cores. The aim of this study is to provide information about the deformation rate in the ice and the corresponding thinning of ice layers at different depths. This information is substantial for the glaciologists in order to build ice dating models and consequently to give a correct interpretation of the climate information which can be found by analyzing ice cores. In this thesis we consider data coming from three different ice cores: the Talos Dome core, the EDML core and the Renland core. Motivated by the ice application, we study how isotropic and stationary noise influences the directional analysis. In fact, due to the relaxation of the ice after drilling, noise bubbles can form within the ice samples. In this context we take two classification algorithms into consideration, which aim to classify points in a superposition of a regular isotropic and stationary point process with Poisson noise. We introduce two methods to visualize anisotropy, which are particularly useful in 3D and apply them to the ice data. Finally, we consider the problem of testing anisotropy and the limiting behavior of the geometric anisotropy transform.
Efficiently Embedding Service Function Chains with Dynamic Virtual Network Function Placement in Geo-Distributed Cloud System

Network Function Virtualization (NFV) and Software-Defined Networks (SDN) enable Internet Service Providers (ISPs) to place Virtual Network Functions (VNFs) to achieve the performance and security benefit without incurring high Operating Expenses (OPEX) and Capital Expenses (CAPEX). In NFV environment, Service Function Chains (SFCs) always need to steer the traffic through a series of VNF instances in predefined orders. Moreover, the required number and placement of VNF instances should be optimized to adapt to dynamic network load. Therefore, it is considerable for ISPs to conduct an optimal SFC embedding strategy to improve the network performance and revenue. In the paper, we study the SFC Embedding Problem (SFC-EP) with dynamic VNF placement in geo-distributed cloud system. We formulate this problem as a Binary Integer Programming (BIP) model aiming to embed SFC requests with the minimum embedding cost. Furthermore, the novel SFC eMbedding APproach (SFC-MAP) and VNF Dynamic Release Algorithm (VNF-DRA) have been proposed to efficiently embed SFC requests and optimize the number of placed VNF instances. Performance evaluation results show that the proposed algorithms can provide higher performance in terms of SFC request acceptance rate, network throughput, and mean VNF utilization rate and efficiently reduce the total VNF running time compared with the algorithms in existing literatures.
Implementation of Message Encryption Algorithms in Real Time Closed Network Systems

In the case of messaging systems used in closed network systems in military and other systems, encryption processes are generally not needed.Since these systems are usually real-time systems, interpretation of messages (encryption of the message and decriyption of the message) will adversely affect time synchronization and traceability. However, this situation also causes significant security vulnerabilities in such critical systems. In this study, different encryption methods were applied to the messaging structures used in military real - time closed network systems.The effects of these applied cipher methods on performance were made by creating three different test environments and the results obtained are presented in detail.