Miracle-dz/UniFAR-FTUs huggingface dataset:
An analysis of TCP reset behaviour on the internet

This paper presents a one-year study of Internet packet traffic from a large campus network, showing that 15-25% of TCP connections have at least one TCP RST (reset). Similar results have also been observed from measurements of other Internet links. The results in this paper show that reset connections arise from local events such as network outages, attacks, or reconfigurations, as well as from global trends in TCP usage. In particular, we identify application-level Web behaviour as the primary contributor to the global trend in reset TCP connections. The most prevalent anomaly is the absence of the normal connection termination handshake. Instead, connections are often reset by the client. We believe that particular implementations of HTTP/TCP connection management cause this global trend.
Scheduling Unrelated Machines by Randomized Rounding

We present a new class of randomized approximation algorithms for unrelated parallel machine scheduling problems with the average weighted completion time objective. The key idea is to assign jobs randomly to machines with probabilities derived from an optimal solution to a linear programming (LP) relaxation in time-indexed variables. Our main results are a $(2+\varepsilon)$-approximation algorithm for the model with individual job release dates and a $(3/2+\varepsilon)$-approximation algorithm if all jobs are released simultaneously. We obtain corresponding bounds on the quality of the LP relaxation. It is an interesting implication for identical parallel machine scheduling that jobs are randomly assigned to machines, in which each machine is equally likely. In addition, in this case the algorithm has running time O(n log n) and performance guarantee 2. Moreover, the approximation result for identical parallel machine scheduling applies to the on-line setting in which jobs arrive over time as well, with no difference in performance guarantee.
''Walking on eggshells to not offend people": Experiences of same-sex student couples at a South African university

CITATION: Lesch, E. , Brits, S. & Naidoo, N. T. 2017. Walking on eggshells to not offend people : experiences of same-sex student couples at a South African university. South African Journal of Higher Education, 31(4):127‒149, doi:10.20853/31-4-893.
Global knockdown of microRNAs affects the expression of growth factors and cytokines in human adipose-derived mesenchymal stem cells

Cell therapies utilizing mesenchymal stem cells (MSCs) have a great potential in many research and clinical settings. The mechanisms underlying the therapeutic effects of MSCs have been studied previously and the paracrine effects elicited by their production of various growth factors and cytokines were recognized as being crucial. However, the molecular controls that govern these paracrine effects remain poorly understood. To elucidate the molecular regulators of this process, we performed a global knockdown of microRNAs (miRNAs) in human adipose-derived mesenchymal stem cells (hADSCs) by inhibiting DGCR8, a key protein in miRNA biogenesis. Global disruption of miRNA biogenesis in hADSCs caused dramatic changes in the expression of subsets of growth factors and cytokines. By performing an extensive bioinformatic analysis, we were able to associate numerous putative miRNAs with these genes. Taken together, our results strongly suggest that miRNAs are essential for the production of growth factors and cytokines in hADSCs. [BMB Reports 2014; 47(8): 469-474]
Controlling overload in networks of SIP servers

The session initiation protocol (SIP) is rapidly being adopted as the signaling protocol for establishing, modifying and terminating multimedia sessions. With the increasing use of SIP in large deployments, it is now becoming apparent that the current SIP design does not easily scale up to large network sizes and SIP servers are not well equipped to handle overload conditions. When a SIP server is operating close to or above its capacity limit, message retransmissions by various SIP timers can cause the network to be severely overloaded and result in an extremely low goodput. In this paper, we first provide a detailed analysis of the behavior of SIP servers under overload. We show that SIP servers are often unable to recover from congestion collapse once it has occurred and that overload can spread throughout a network of SIP servers. We then discuss mechanisms and algorithms for controlling overload in these servers. We found that performing overload control locally at a server provides a simple remedy for light cases of overload; however, it is ineffective in handling higher amounts of load. Finally, we investigate distributed overload control mechanisms for SIP and show that they are effective in controlling overload of SIP servers.
Wicked tendencies in policy problems: rethinking the distinction between social and technical problems

Abstract Complex or intractable policy problems, often called ‘wicked’ problems, have been a feature of public policy research since the early 1970s. Observers have generally assumed that these wicked problems constitute a distinct category of policy problems, based on the notion that some problems – those characterised as substantially technical or scientific in nature – lend themselves to traditional linear problem-solving methods, whereas other problems that are social in nature tend to be wicked. By examining three cases where scientific knowledge is central to the debate – climate change, genetically modified foods and hydraulic fracturing – we argue that all policy problems can exhibit wicked tendencies, regardless of the amount of scientific information available to decision-makers. Therefore, the reliance on increased information in resolving wicked problems is unlikely to be sufficient or effective.
On the relations of semantic and acoustic properties of emotions

In the present study, the relation between the semantic content and different acoustic parameters of emotional speech are analyzed. The analyzed corpus includes happiness, neutral state, and anger used as semantic content as well as emotional state of the speaker also comprising mismatch conditions. We have analyzed voice source quality parameters in a subset of the acoustic signals. The data indicate that the opening quotient and the glottal opening tendentially reflect differences between anger and neutral statements. Breathiness and roughness, estimated by the harmonic-to-noice ratio (HNR) show significantly higher HNR in the sentences expressed with anger than the neutral expressions.
The LATUX workflow: designing and deploying awareness tools in technology-enabled learning settings

Designing, deploying and validating learning analytics tools for instructors or students is a challenge requiring techniques and methods from different disciplines, such as software engineering, human-computer interaction, educational design and psychology. Whilst each of these disciplines has consolidated design methodologies, there is a need for more specific methodological frameworks within the cross-disciplinary space defined by learning analytics. In particular there is no systematic workflow for producing learning analytics tools that are both technologically feasible and truly underpin the learning experience. In this paper, we present the LATUX workflow, a five-stage workflow to design, deploy and validate awareness tools in technology-enabled learning environments. LATUX is grounded on a well-established design process for creating, testing and re-designing user interfaces. We extend this process by integrating the pedagogical requirements to generate visual analytics to inform instructors' pedagogical decisions or intervention strategies. The workflow is illustrated with a case study in which collaborative activities were deployed in a real classroom.
Teens In Social Media: Data-driven Comparative Analysis On Behaviors In Instagram

Social media plays an important role in connecting people and making them interact with each other. Its influence is more direct and stronger to teens, because they are more active and engaged in using social media than other generations. Much research has presented teens’ high use and engagement as well as characteristics in social media; however, the way of analyzing them has mostly relied on ethnographic accounts or quantitative analyses with small datasets. In this thesis, I present the analysis of how teens use social media differently using a large dataset of Instagram. First, I present the characteristics of Instagram use by people with respect to structure, influence, and context, in order to see its general use patterns. Second, based on the methods used in the first study, I present how teens use and engage in Instagram. I describe a novel method to detect teens and adults using user profiles, mixing with textual and facial recognition approaches. With around 27,000 teens and adults identified, I present the comparative study of the two user groups. The study results highlight that (1) teens tend to post fewer but remove more photos, influenced by the number of Likes; (2) teens tend to be more engaged in Liking and commenting and to express their emotions and social interests, than adults; (3) teens tend to have less diverse photo content. Lastly, I will discuss theoretical and practical interpretations and implications of the results, as well as future directions of my research. iv TABLE OF CONTENTS LIST OF FIGURES . v LIST OF TABLES . vii Chapter
Modification of the discharge of lateral geniculate neurons during visual learning

Visually conditioned heart rate change in the pigeon has been developed as a vertebrate model system for cellular analysis of associative learning. Previous studies have characterized the behavior, largely delineated the neural circuitry mediating the conditioning, and estimated the central processing time for the conditioned response. Most recently, this system has been used to investigate neuronal activity during conditioning along the visual pathways that transmit the conditioned stimulus (CS) information. It was first shown that neither maintained nor CS-evoked discharge of retinal ganglion cells changes during conditioning. Subsequently, we found that the thalamic and telencephalic components of the ascending tectofugal pathway show associative modification. We report here studies of the thalamofugal pathway, the avian homolog of the mammalian geniculocortical system. Single-cell activity was recorded in the thalamic relay of this pathway, the dorsal lateral geniculate equivalent (LGNe). This provided an opportunity to evaluate the generality of the training-induced modification found along the tectofugal pathway, and to determine if such modification occurs as peripherally as retinorecipient neurons. The results show that almost all LGNe neurons (97%) respond phasically to the onset of whole-field illumination. Most (94%) also respond to the unconditioned stimulus (US), footshock, some with increased and others with decreased discharge. Of cells receiving convergent input, those responding with decreased discharge to the US showed associative change (52%). Neurons that did not respond to both the CS and US, or that responded to the US with increased discharge, did not show associative modification. These findings suggest that the visual pathways transmitting CS information are not merely input lines, but undergo training-induced modification; such modification can occur as peripherally as the retinorecipient neurons of these pathways; and CS- US convergence is necessary but not sufficient for associative modification, since modifiability is apparently contingent on specific US response properties.
Status of rheumatic heart disease in rural Pakistan

Objectives: To determine the community based prevalence of rheumatic heart disease (RHD) in the rural population of the district of Rahim Yaar Khan in Pakistan. Subjects and methods: A representative sample of the rural population of Rahim Yaar Khan district was selected. RHD was screened for by physical examination and the diagnosis was confirmed with echocardiographic Doppler studies. Sociodemographic data on each screened person were collected. Results: 54 cases of RHD were found among the 9430 people screened (prevalence of 5.7 in 1000, 95% confidence interval 4.2 to 7.2). Females were significantly more likely to be affected. There was no significant relation with other factors studied (education, crowding, and socioeconomic status). Less than 20% of those found to have RHD were aware of their diagnosis before participation in this study and only three affected people (8%) were taking rheumatic prophylaxis. Conclusions: There is a high prevalence of RHD among the rural population of Pakistan. The prevalence has not declined over the past three decades. Nearly all people with RHD, including most of those who know their diagnosis, do not receive the benefit of potentially life saving secondary prevention measures.
Special AT-rich sequence-binding protein-1 participates in the maintenance of breast cancer stem cells through regulation of the Notch signaling pathway and expression of Snail1 and Twist1

The stem cell populations in cancerous tissues and cell lines vary widely and are often associated with aggressive cases of breast cancer. Despite research on the topic, the mechanism underlying the regulation of the breast cancer stem cell (BCSC) population within tumors remains to be fully elucidated. To investigate the function of special AT-rich sequence-binding protein-1 (SATB1) in the maintenance of the BCSC population, SATB1 was overexpressed with lentivirus in MCF-7 cells or knocked down with shRNA-lentivirus in BT-549 cells. The effects of SATB1 overexpression or knockdown on mammosphere formation, the size of the of BCSC population, cell invasion and tumorigenesis were investigated. Activation of the Notch signaling pathway and expression of Snail1 and Twist1 were also examined in the cells. Overexpression of SATB1 in MCF-7 cells was observed to increase mammosphere formation, the size of the BCSC population, cell invasion and tumorigenesis, accompanied by an increase in the activation of Notch signaling and expression levels of Snail1 and Twist1. Conversely, knockdown of SATB1 in BT-549 cells produced the opposite effects. The results indicated that expression of SATB1 may increase the size of the BCSC population via the activation of the Notch signaling pathway and by increasing expression levels of Snail1 and Twist1.
Formalizing software ecosystem modeling

Currently there is no formal modeling standard for software ecosystems that models both the ecosystem and the environment in which software products and services operate. Major implications are (1) software vendors have trouble distinguishing the specific software ecosystems in which they are active and (2) they have trouble using these ecosystems to their strategic advantage. In this paper we present and formalize a standards-setting approach to software product and software supply network modeling. Applying this approach enables software vendors to communicate about relationships in the software supply network, theorize about weak spots/links in their business model and anticipate upcoming changes in the software ecosystem.
RARE: An Energy-Efficient Target Tracking Protocol for Wireless Sensor Networks

Energy efficiency for target tracking in wireless sensor networks is very important and can be improved by reducing the number of nodes involved in communications. We propose two algorithms, RARE-area and RARE-node to reduce the number of nodes participating in tracking and so increase energy efficiency. The RARE-area algorithm ensures that only nodes that receive a given quality of data participate in tracking and the RARE-node algorithm ensures that any nodes with redundant information do not participate in tracking. Simulation studies show significant energy savings are obtained with implementation of either the RARE-area algorithm alone or both RARE-area and RARE-node algorithms together.
Surface-based versus volume-based fMRI group analysis: a case study

Being able to detect reliably functional activity in a popula- tion of subjects is crucial in human brain mapping, both for the under- standing of cognitive functions in normal subjects and for the analysis of patient data. The usual approach proceeds by normalizing brain volumes to a common 3D template. However, a large part of the data acquired in fMRI aims at localizing cortical activity, and methods working on the cortical surface may provide better inter-subject registration than the standard procedures that process the data in 3D. Nevertheless, few as- sessments of the performance of surface-based (2D) versus volume-based (3D) procedures have been shown so far, mostly because inter-subject cortical surface maps are not easily obtained. In this paper we present a systematic comparison of 2D versus 3D group-level inference procedures, by using cluster-level and voxel-level statistics assessed by permutation, in random e ects (RFX) and mixed-e ects analyses (MFX). We nd that, using a voxel-level thresholding, and to some extent, cluster-level thresholding, the surface-based approach generally detects more, but smaller active regions than the corresponding volume-based approach for both RFX and MFX procedures, and that surface-based supra-threshold regions are more reproducible by bootstrap.
Nanoporous Metals by Alloy Corrosion: Formation and Mechanical Properties

Nanoporous metals prepared by the corrosion of an alloy can take the form of monolithic, millimeter-sized bodies containing approximately 10^15 nanoscale ligaments per cubic millimeter. The ligament size can reach down to the very limits of stability of nanoscale objects. The processes by which nanoporous metals are formed have continued to be fascinating, even though their study in relation to surface treatment, metal refinement, and failure mechanisms can be traced back to ancient times. In fact, the prospect of using alloy corrosion as a means of making nanomaterials for fundamental studies and functional applications has led to a revived interest in the process. The quite distinct mechanical properties of nanoporous metals are one of the focus points of this interest, as relevant studies probe the deformation behavior of crystals at the lower end of the size scale. Furthermore, the coupling of bulk stress and strain to the forces acting along the surface of nanoporous metals provide unique opportunities for controlling the mechanical behavior through external variables such as the electrical or chemical potentials.
Comparing available rainfall gridded datasets for West Africa and the impact on rainfall-runoff modelling results, the case of Burkina-Faso

Monthly rainfall data in Burkina-Faso, West Africa, over a period of 77 years are extracted from three different gridded data sets, available either on the web : CRU (Climatic Research Unit, Norwich, UK), SIEREM (HydroSciences Montpellier, France), or from the National Meteorological Center of Burkina-Faso. With a view to modelling the runoff-rainfall relationship at the monthly time step, these data are used at the 0.5°*0.5° scale. Despite mean, minimum, standard deviation and inter-annual variability being very similar for the period 1922 to 1998, the three gridded data sets used show an important spatial variability of values with time, and some differences are observed which lead to significantly different runoff-rainfall simulations. Comparison of the rainfall grids has shown that differences between the precipitation grids are more pronounced during years when the rainfall is lower; this also applies to areas where the rainfall is lower. The three different rainfall grids produce differences in mean rainfall of 4 to 11%, depending on the grids that are compared. While these results are obviously specific to the station networks and interpolation method used, they provide an indication of the differences that can arise. It is recommended that as many stations as possible are used to better assess areal rainfall. These biases have a strong influence on the results of the runoff-rainfall modelling (using the GR2M conceptual model) : the Nash criteria show differences of about 20% and calculated flow of 30% to 40%. This study illustrates the levels of uncertainty when using available rainfall gridded data sets, for rainfall-runoff studies in West African developing countries, which is important in the context of predicting water resources for the future from the GCM outputs for the 21st century.
Applying Scrum Framework in the IT Service Support Domain

This paper is presenting an idea of applying the Scrum framework in the IT service support domain. Scrum framework is mainly used with conjunction of other agile methods in software development domain, but almost, no reporting for its usage in the support of that software, except in few cases. Scrum framework can be applied at small, medium, and as well as large organizations, and companies. We expect that Scrum can change the IT service support from cost center into revenue and more value added center. We also expect that Scrum framework can change some companies' profiles. The results achieved in a real life example are prosperous and fruitful, as we will present in this paper a reported real-life example of applying the Scrum framework in the IT Service Support along with the results achieved. In the case study we present here in the previous work section the framework was applied in a horizontal fashion. We will propose a vertical way of the framework application, and another new idea of dynamic Sprint planning along some of the expected results. As this idea is newly applied to that domain, so the horizontal, the vertical framework application ways, or the dynamic sprint planning idea will need more experimenting, and documenting in order to reach a solid conclusions, and results. We will recommend some of the future work that need to be done in that domain, and scope in order to document the topic more, rather than being just some self-experiences.
How Emotional Mechanism Learn and Helps Other Types of Learning in a Cognitive Agent

Research in human neurobiology sustains the idea that emotions play a role, sometimes crucial, in most decisions and actions taken. Every input from perceptual mechanism passes through the amygdala before affecting action selection, sometimes temporarily bypassing detailed cortical interpretation. We describe our reproduction of these emotional mechanisms in our cognitive autonomous agent, CTS (Conscious Tutoring System), and hint at repercussions on its tutoring behaviors. The model replicates the amygdalapsilas emotional influence over different parts of the system as a means of preparing the system for action, biasing action selection, and improving the agent's self-resilience in an unknown or changing environment. It all sums up to a way of improving the agentpsilas fitness and autonomy.
Deviance Information Criterion for Comparing Stochastic Volatility Models

Bayesian methods have been efficient in estimating parameters of stochastic volatility models for analyzing financial time series. Recent advances made it possible to fit stochastic volatility models of increasing complexity, including covariates, leverage effects, jump components, and heavy-tailed distributions. However, a formal model comparison via Bayes factors remains difficult. The main objective of this article is to demonstrate that model selection is more easily performed using the deviance information criterion (DIC). It combines a Bayesian measure of fit with a measure of model complexity. We illustrate the performance of DIC in discriminating between various different stochastic volatility models using simulated data and daily returns data on the Standard & Poors (S&P) 100 index.