Miracle-dz/UniFAR-FTUs huggingface dataset:
Shifting sands: The decoloniality of geography and its curriculum in South Africa

PUBLISHED: 26 September 2019 Since the era of European exploration, the world has been conquered and nations subdued by imperial powers.1 The evidence of colonisation is explicitly seen in the territorial demarcations on the global map, borders that at times seem to follow little more than natural boundaries chosen to divide territories between competing powers. The borders that demarcate African countries and separate its people are a clear illustration of this. It is within these borders that sovereign states now function and across these borders that international interactions occur. Geography, as an academic discipline which is concerned with both the physical environment and human interactions that occur within and between the borders of nation states, cannot ignore the politics of space. To date, the understanding and production of geographical knowledge continue to be informed by the European colonial modalities of power.1,2 Even though decolonial scholars acknowledge that the modern episteme is saturated with coloniality1, the geography curricula in African higher education does not show or encourage a different way of imagining or describing indigenous places3. One example of this is how indigenous knowledge, and African and indigenous scholarships, continue to be erased or subsumed.4 Much of the current curricula content continue to exclusively credit only international explorers, e.g. Admiral Antonio with Table Mountain, yet most explorers used local field guides who introduced them to most spaces on the continent. Another example is how the curricula are still referring only to colonial names of places despite many indigenous names of places being known in local languages. Curricula also have a long way to go to sufficiently incorporate local ecological knowledge and practices that have wider implications and practical application, especially in topics of relevance to the higher education geography curricula. Evidence already exists that supports that African mythology can be credited for conservation5,6, yet this is not adequately reflected in African geography curricula. It can, however, be justifiably argued that this omission may be a mere consequence of the mediation of knowledge by different communication technologies, which have uneven power dynamics, especially at the global scale.5 It is therefore imperative that geography as a discipline, and geographers as scholars, take it upon themselves to understand the centrality of this discipline within the call to de-colonise higher education and make an ardent effort towards building de-colonial curricula.7 Such acknowledgement, however, can only support the proposition of Bloor8, which is to interrogate popular discourses and established bodies of knowledge through careful historical geographical scholarship to the African geography higher education curricula. One way of doing so, could be by considering the application of post-colonial theory in tackling the decolonisation of the geography curricula.
Power and thrust coefficients of the horizontal axis tidal stream turbine with different twist angles, blade numbers, and section profiles

The purpose of this research was to investigate the power and thrust coefficients of a horizontal axis tidal stream turbine (HATST) with different blade geometries, including twist angles, blade numbers, and section profiles. The RANS equations and Star-CCM+ commercial software were used to numerically analyze these variables. Furthermore, the turbulence model used in this study is a Realisable k-ε turbulent model. Nine different models were defined by changing the twist angle, thickness, camber, and blade numbers. The results are presented, and the power and thrust coefficients are compared against TSR for each of the nine different models. The pressure distribution and flow velocity contour are also presented and discussed.
Topography Modulates Effects of Nitrogen Deposition on Asymbiotic N2 Fixation in Soil but not Litter or Moss in a Secondary Karst Forest

Evidence shows that nitrogen (N) addition may suppress or have no significant effect on asymbiotic N2 fixation (ANF) in soil, litter, or moss. However, the mechanisms underlying the differential responses of ANF to N addition are not well understood. The main objectives of the current study were to assess how ANF in soil, litter, and moss responds to N addition and whether topography modulates the responses of ANF in soil, litter, or moss to N addition. We conducted an N addition experiment at two topographic positions, that is, valley and slope of a secondary karst forest in southwest China. Three N addition treatments, that is, control (0 kg N·ha−1·year−1), moderate N addition (N50, 50 kg N·ha−1·year−1), and high N addition (N100, 100 kg N·ha−1·year−1) were included. Nitrogen addition had no significant effect on moss ANF at both topographic positions. Soil ANF was lower by 17.1% in the N100 plots relative to the control in the valley but was not significantly altered by N addition on the slope. In contrast, litter ANF was suppressed by N addition at both topographic positions by 77.9% to 87.4%. Our findings suggest that topography may modulate the responses of ANF to N addition, but the modulation effects likely differ among different ecosystem compartments.
SURFACE WATER POTENTIAL ASSESSMENT AND DEMAND SCENARIO ANALYSIS IN SOMODO WATERSHED, SOUTH WEST ETHIOPIA

Lack of sufficient knowledge about available water resources and coordination in water resources management often causes competition of fixed water resources among users. This surface water potential assessment and demand scenario analysis was initiated with an objective of surface water potential assessment and water demand requirement in the watershed to maximize the overall benefits without compromising ecological requirements in Somodo watershed. To achieve this goal soil and water assessment tool (SWAT) model was used to determine the surface water potential of the watershed after sensitivity analysis, calibration and validation of the model by SWAT_CUP. Water Evaluation and Planning (WEAP) model was used to determine water demands. Different scenarios were also developed to determine the future water demand, supply requirement and unmet demand in two time horizons from 2018 up to 2050. The water demand for coffee Arabica, viz crop water requirement and irrigation water requirement was also determined using CROPWAT 8.0 model. The result revealed that the total surface water potential from the watershed was 56.75MCM annually during the study period (2017). Both the calibration and validation result showed a satisfactory performance with a value of R and NSE of 0.795, and 0.68 for calibration and 0.821, and 0.57 for validation, respectively. During the study period (2017) demands for domestic, irrigation, livestock and environmental flow requirements were 0.22MCM, 0.14MCM, 0.015MCM and 5.6MCM, respectively. 0.034MCM was the total water demand for the cultivation of five hectares of coffee (coffee Arabica L.) in Somodo watershed using irrigation. In 2017 the total water demand required was 6.07MCM which is 11% of the available surface water potential and there was no unmet demand annually, but there was shortage in December because of low flow condition in that month. Harvesting of rainfall during rainy season to use during the deficit (shortage) time in December was recommended.
Calibration of the Canadian FWI system for the territory of Europe

The role played by the meteorology in the development of a forest fire is widely recognized. There are several models to assess the risk of forest fires used by the authorities to define the state of readiness of the fire-fighting resources to suppress them in their early stages. The Fire Weather Index (FWI) of the Canadian Fire Danger System, widely used in several parts of the world, is a composite index that represents fire weather conditions quite well. An important aspect in the application of the FWI is the definition of the threshold values to determine the fire danger classes for a given region and day. One of the simplest methods to define the classes is to use percentiles based on historical data, but this method lacks information regarding wildfire history and its relation to FWI. To obtain a credible assessment of the fire danger using the FWI it is important to perform a calibration to determine the limiting values of FWI for each class. Probabilities of fire duration exceeding specified thresholds are then used to calibrate FWI leading to the definition of fire danger classes. Although the Canadian Fire Danger System proposes an indicative table of limiting values for the five original fire danger classes that are usually adopted, these limiting values are not universal and have to be determined for a given region and season. This study that was requested by the Joint Research Centre of Europe (JRC), aims to produce a calibration for the FWI based on historical wildfire data, for the territory of Europe, providing an updated table of threshold values to have a better definition of the risk classes of each region. The spatial division of the various countries and regions covered by the daily analysis of fire risk was defined to be the level 3 of the Nomenclature of territorial units for statistics (NUTS3). The methodology to calibrate the fire danger classes based on the statistical data of daily FWI, number of fires and burned area for each NUTS3, was performed between 2006 and 2015.
Analysis of Classification Methods for Identifying Stands for Commercial Thinning Using LiDAR

Abstract Commercial thinning (CT) is an important tool that meets a diverse set of forest management objectives, including the generation of intermediate revenue, promotion of regeneration tree growth, and the modification of vertical and horizontal fuel structure for wildfire mitigation. Using a set of 653 fixed radius plots and a coincident LiDAR acquisition, we compared three different classification methods to predict CT eligibility for Douglas-fir (Pseudotsuga menziesii) stands in southwestern Oregon. We assessed logistic regression (LOG), random forests (RF), XGBoost (XGB) to classify areas eligible for CT operations based on three structural attributes, volume (VOL), basal area (BA) and Curtis’ Relative Density index (CRD). We also assessed their predictive performance and reliability via cross-validation at different sample sizes. We used the area under the receiver operating characteristic curve (AUC) as our primary performance measure. Estimated AUCs were 0.86, 0.77 and 0.68 for XGB, RF and LOG, respectively. We observed that classifier performance stabilized between sample sizes of 200 and 300 plots, which suggests that the development of a CT eligibility classifier is appropriate for operational applications of the method with similar sample sizes and large area attributes.
Improved reservoir characterization by employing hydraulic flow unit classification in one of Iranian carbonate reservoirs

Capillary pressure curves is of great importance in reservoir characterization. Due to the reservoir heterogeneity, no single capillary pressure curve can be used for the entire reservoir depth. This paper aims to examine the application of different techniques of hydraulic flow unit (HFU) classifications in overcoming the extreme heterogeneity of the reservoir in order to improve normalization of capillary pressure in one of the Iranian carbonate oil reservoirs. In this study, well log, routine and specific core analysis lab data have been used to identify flow units by employing different techniques in a heavy oil carbonate reservoir in the south of Iran. These techniques include gamma ray and density log method, flow zone indicator, capillary pressure curves and Winland parameter. Then, mercury injection data has been used by employing Desouky's method to normalize capillary pressure curves for each identified flow unit. According to this study HFU classification significantly improved normalizing of capillary pressure curves. Cited as : Rafiei, Y. , Motie, M. Improved reservoir characterization by employing hydraulic flflow unit classifification in one of Iranian carbonate reservoirs. Advances in Geo-Energy Research, 2019, 3(3): 277-286, doi: 10.26804/ager.2019. 03.06.
Deep Bottom Mixed Layer Drives Intrinsic Variability of the Antarctic Slope Front

The Antarctic Slope Front (ASF) is located along much of the Antarctic continental shelf break and helps to maintain a barrier to the movement of Circumpolar Deep Water (CDW) onto the continental shelf. The stability of the ASF has a major control on cross-shelf heat transport and ocean-driven basal melting of Antarctic ice shelves. Here, the ASF dynamics are investigated for continental shelves with weak dense shelf water (DSW) formation, which are thought to have a stable ASF, common for regions in East Antarctica. Using an ocean process model, this study demonstrates how offshore bottom Ekman transport of shelf waters leads to the development of a deep bottom mixed layer at the lower continental slope, and subsequently determines an intrinsic variability of the ASF. The ASF variability is characterized by instability events that affect the entire water column and occur every 5–10 years and last for approximately half a year. During these instability events, the cross-shelf density gradient weakens and CDW moves closer to the continent. Stronger winds increase the formation rate of the bottom mixed layer, which causes a subsequent increase of instability events. If the observed freshening trend of continental shelf waters leads to weaker DSW formation, more regions might be vulnerable for the ASF variability to develop in the future.
Numerical Simulation Capabilities for Ground Shock Prediction due to Subsurface Explosion

The ground shock produced by subsurface explosion near buried structures generally represents the dominant threat to these facilities. Due to various constraints, pertinent experimental data are extremely scarce. Adequately detailed numerical simulation thus becomes a desirable alternative. The use of commercially available codes, which are capable of solving non-linear dynamic problems, validated against proven prediction techniques and experimental data, can provide a cost-effective means of examining the highly dynamic processes involved in the subsurface explosion and ground shock propagation. This paper sets out to examine the potential of numerical analysis for investigating ground shock phenomena from underground explosion in different sites. The finite element code AUTODYN, which is available in 2-dimensional (2D) and 3-dimensional (3D) formats was employed. The study presents best material models necessary to produce good correlation with free filed resultants obtained from filed tests and CONWEP, an established experimentally-based prediction technique. The validated numerical model is then used to study the ground shock propagation in three different rock types; hard, moderate and soft rocks.
Machine-learning based Hybrid Method for Surface Defect Detection and Categorization in PU Foam

Foam making is an important industry, their main applications being foam mattresses. Hence, their production in the industries is subject to very strict safety checks to ensure their quality. There are many types of defects that can arise during their manufacturing process, like holes, cuts, a misconfiguration in the material and many more. These defects are reviewed manually which leads to an inadequate accuracy and many defects are not detected. This paper proposes a novel approach that identifies defects in the foam material and on the surface using a hybrid method. Both supervised and unsupervised approaches are used to categorize materials based on normal or defective, including the type of defect. Then the reliable model is chosen according to the precision rates of both the models.
Flood Risk Evaluation in the Middle Reaches of the Yangtze River Based on Eigenvector Spatial Filtering Poisson Regression

A Poisson regression based on eigenvector spatial filtering (ESF) is proposed to evaluate the flood risk in the middle reaches of the Yangtze River in China. Regression analysis is employed to model the relationship between the frequency of flood alarming events observed by hydrological stations and hazard-causing factors from 2005 to 2012. Eight factors, including elevation (ELE), slope (SLO), elevation standard deviation (ESD), river density (DEN), distance to mainstream (DIST), NDVI, annual mean rainfall (RAIN), mean annual maximum of three-day accumulated precipitation (ACC) and frequency of extreme rainfall (EXE) are selected and integrated into a GIS environment for the identification of flood-prone basins. ESF-based Poisson regression (ESFPS) can filter out the spatial autocorrelation. The methodology includes construction of a spatial weight matrix, testing of spatial autocorrelation, decomposition of eigenvectors, stepwise selection of eigenvectors and calculation of regression coefficients. Compared with the pseudo R squared obtained by PS (0.56), ESFPS exhibits better fitness with a value of 0.78, which increases by approximately 39.3%. ESFPS identifies six significant factors including ELE, DEN, EXE, DIST, ACC and NDVI, in which ACC and NDVI are the first two main factors. The method can provide decision support for flood risk relief and hydrologic station planning.
Propuesta de diseño de instrumento para analizar vídeo-lecciones en MOOC

El artículo presenta el proceso de construcción y validación de un instrumento para valorar la estructura de vídeo-lecciones de cursos masivos en línea, MOOC. El instrumento divide la vídeo-lección en momentos de la clase: inicio, desarrollo y cierre, para revisar de qué manera cada apartado aporta a la construcción de la narración. La justificación de este estudio se basa en la necesidad de generar propuestas para la producción de vídeos en cursos masivos, toda vez que algunos replican modelos tradicionales de transmisión de información en sus vídeos. En la primera parte del texto, se explica el proceso de diseño y los soportes teóricos que enmarcan los bloques de preguntas, así como el resultado de la valoración de los expertos y pilotaje del instrumento y los resultados. Al final, el artículo ofrece perspectivas para el diseño de vídeo-lecciones y para contar con instrumentos que le permitan a los docentes y a los diseñadores instruccionales de cursos virtuales hacer una lista de chequeo de los principios de Storytelling y narrativa audiovisual que refuercen los discursos contenidos en las vídeo-lecciones. Se concluye con una propuesta de uso del instrumento para abrir nuevas líneas de investigación que apoyen la producción de vídeo-lecciones y con el planteamiento de ideas para usar elementos de televisión vía streaming como Netflix a las secuencias didácticas de cursos virtuales.
The perceived quality of light-field video services

Real-time video transmission services are unquestionably dominating the flow of data over the Internet, and their percentage of the global IP packet traffic is still continuously increasing. As novel visualization technologies are emerging, they tend to demand higher bandwidth requirements; they offer more visually, but in order to do so, they need more data to be transmitted. The research and development of the past decades in optical engineering enabled light-field displays to surface and appear in the industry and on the market, and light-field video services are already on the horizon. However, the data volumes of high-quality light-field contents can be immense, creating storing, coding and transmission challenges. If we consider the representation of light-field content as a series of 2D views, then for a single video frame, angular resolution determines the number of views within the field of view, and spatial resolution defines the 2D size of those views. In this paper, we present the results of an experiment carried out to investigate the perceptual differences between different angular and spatial resolution parametrization of a light-field video service. The study highlights how the two resolution values affect each other regarding perceived quality, and how the combined effects are detected, perceived and experienced by human observers. By achieving an understanding of the related visual phenomena, especially degradations that are unique for light-field visualization, the design and development of resource-efficient light-field video services and applications become more straightforward.
Urban expansion in the forests of the Puget Sound region.

MacLean, Colin D. ; Bolsinger, Charles L. 1997. Urban expansion in the forests of the Puget Sound region. Resour. Bull. PNW-RB-225. Portland, OR: U.S. Department of Agriculture, Forest Service, Pacific Northwest Research Station. 17 p. As part of a 1979 forest resource inventory, over 9,000 points on aerial photographs were sorted into three development zones-primary forest, suburban, and urban. These same points were reexamined in 1989, and zone changes were noted. This report summarizes urban expansion into the primary forest lands of the Puget Sound region (Island, King, Kitsap, Pierce, San Juan, Skagit, Snohomish, Thurston, and Whatcom Counties). In addition, forest statistics for non-industrial private timberlands within the suburban and urban zones are presented.
Millimeter-Wave/Sub-Terahertz CMOS Transceivers for High-Speed Wireless Communications

Author(s): Kang, Shinwon | Advisor(s): Niknejad, Ali M | Abstract: Millimeter-wave and sub-terahertz frequency bands are available for wideband applications such as high data-rate communication systems. As the respective wavelength is on the order of a millimeter, a compact on-chip antenna can be designed, thereby reducing the overall form factor and obviating expensive off-chip packaging. However, the channel propagation loss increases significantly with the frequency. Although CMOS technology is prevalent in digital processing and data communication, CMOS devices are lossy and inefficient at such high frequencies. Thus, it is challenging to implement an efficient and wideband transceiver at sub-terahertz frequencies using CMOS technology.The aim of this dissertation is to demonstrate sub-terahertz wireless links for high-speed chip-to-chip communication in CMOS. First, transceiver architectures and building blocks are discussed to address the challenges and limitations of the CMOS process. Two fully integrated CMOS transceivers, a 260 GHz OOK transceiver and a 240 GHz QPSK/BPSK transceiver, are then demonstrated using on-chip antennas. Frequency multiplication and mixer-first design are employed to operate beyond the cut-off frequency. In the QPSK modulation, a maximum data rate of 16 Gbps is realized with an energy efficiency of 30 pJ/bit.These demonstrations show that millimeter-wave/sub-terahertz wireless communication can be a promising solution for high-speed chip-to-chip communication. Improvements in the energy efficiency and silicon area of these wireless links can result in replacing or complementing existing wired links.