Miracle-dz/UniFAR-FTUs huggingface dataset:
Reveal the relationships among student ' s participation and its outcomes on eLearning environments : Case study

known about the impact of measurable reading access to a forum and other resources. We have developed a tool to study this aspect through visual analysis. Results from this study showed that not only participation on electronic discussion fora, such as reading or posting, but also the reading access to the resource, can alert about the student's performance. This came about after proving the existence of a strong influence relationship between the frequency of reading access to discussion fora and the frequency of access to posting fora, as well as between the frequency of reading access to resources and the frequency of access to posting fora in the outcome of the students. However, we have found that the union of the variables above, i.e., frequency of posts in fora, reading of discussion fora and reading of resources can be visually analyzed, thus obtaining a better visualization of the patterns of students' performance.
Local Autonomous Robot Navigation Using Potential Fields

The potential fields method for autonomous robot navigation consists essentially in the assignment of an attractive potential to the goal point and a repulsive potential to each of the obstacles in the environment. Several implementations of potential fields for autonomous robot navigation have been reported. The most simple implementation considers a known environment where fixed potentials can be assigned to the goal and the obstacles. When the obstacles are unknown the potential fields have to be adapted as the robot advances, and detects new obstacles. The implementation of the potential fields method with one attraction potential assigned to the goal point and fixed repulsion points assigned to the obstacles, has the important limitation that for some obstacle configurations it may not be possible to produce appropriate resultant forces to avoid the obstacles. Recently the use of several adjustable attraction points, and the progressive insertion of repulsion points as obstacles are detected online, have proved to be a viable method to avoid large obstacles using potential fields in environments with unknown obstacles. In this chapter we present the main characteristics of the different approaches to implement local robot navigation algorithms using potential fields for known and partially known environments. Different strategies to escape from local minima, that occur when the attraction and repulsion forces cancel each other, are also considered.
Free $n$-distributions: holonomy, sub-Riemannian structures, Fefferman constructions and dual distributions

This paper analyses the parabolic geometries generated by a free $n$-distribution in the tangent space of a manifold. It shows that certain holonomy reductions of the associated normal Tractor connections, imply preferred connections with special properties, along with Riemannian or sub-Riemannian structures on the manifold. It constructs examples of these holonomy reductions in the simplest cases. The main results, however, lie in the free 3-distributions. In these cases, there are normal Fefferman constructions over CR and Lagrangian contact structures corresponding to holonomy reductions to SO(4,2) and SO(3,3), respectively. There is also a fascinating construction of a `dual' distribution when the holonomy reduces to $G_2'$.
L-glutamate efflux with Corynebacterium glutamicum: why is penicillin treatment or Tween addition doing the same?

Corynebacterium glutamicum is known for its ability to massively excrete cellularly synthesized L-glutamate. Together with Mycobacteria and Nocardia this bacterium belongs to the CMN group of the Gram-positive eubacteria. The capacity of C. glutamicum to excrete glutamate has been used for more than 40 years to produce this amino acid in ever increasing quantities of currently about 10 6 tonnes/year (Hodgson, 1994). The wild type does not usually excrete glutamate. However, in practical exercises, any student can achieve the impressive concentration of about 100 mM glutamate from 220 mM glucose by simply adding 1.5% Tween 60 to wild-type C. glutamicum. Moreover, glutamate excretion can be stimulated by a surprisingly diverse array of treatments. In addition to theTween treatment (treatment i), these include: (ii) addition of local anaesthetics, (iii) incubation of the biotin-auxotrophic wild type under biotin limitation, (iv) use of oleic acid auxotrophic mutants, (v) use of glycerol minus mutants, (vi) addition of penicillin, or (vii) use of lysozyme-sensitive mutants. Although there have long been indications that fatty acid synthesis influences glutamate efflux in some way or another, molecular knowledge is very limited, and altered fatty acid synthesis does not explain all the treatments; for example, having peptidoglycan as a target. There is neither an explanation of why penicillin treatment results in glutamate efflux, nor is there a model unifying the variety of treatments. Only recently have two genes been shown to be implicated in the glutamate efflux properties of C. glutamicum (Kimura et al., 1999, Hirasawa et al., 2000). However, the functions of these genes are unknown. The general absence of a model unifying the different treatments is probably best reflected by a title in a recent textbook " Puzzle of Membrane Permeability " summarizing what is known on glutamate efflux concerning C. glutamicum (Nikaido, 1995). We now propose that at least one common feature of the various treatments noted above deals with the special structure of the cell envelope of C. glutamicum. Our hypothesis takes advantage of recently obtained knowledge concerning the mycobacterial cell wall structure and its role in the control of solute movement. Characteristic of Gram-positive bacteria in the CMN group, including C. glutamicum and Mycobacteria, is the existence of two lipid layers as part of their envelope. The first is the ubiquitous inner cytoplasmic membrane which contains the glycerophospholipids found in most other biological membranes. This might contain the glutamate exporter. Obviously, carrier-mediated export is …
Scaling SVM and Least Absolute Deviations via Exact Data Reduction

The support vector machine (SVM) is a widely used method for classification. Although many efforts have been devoted to develop efficient solvers, it remains challenging to apply SVM to large-scale problems. A nice property of SVM is that the non-support vectors have no effect on the resulting classifier. Motivated by this observation, we present fast and efficient screening rules to discard non-support vectors by analyzing the dual problem of SVM via variational inequalities (DVI). As a result, the number of data instances to be entered into the optimization can be substantially reduced. Some appealing features of our screening method are: (1) DVI is safe in the sense that the vectors discarded by DVI are guaranteed to be non-support vectors; (2) the data set needs to be scanned only once to run the screening, and its computational cost is negligible compared to that of solving the SVM problem; (3) DVI is independent of the solvers and can be integrated with any existing efficient solver. We also show that the DVI technique can be extended to detect non-support vectors in the least absolute deviations regression (LAD). To the best of our knowledge, there are currently no screening methods for LAD. We have evaluated DVI on both synthetic and real data sets. Experiments indicate that DVI significantly outperforms the existing state-of-the-art screening rules for SVM, and it is very effective in discarding nonsupport vectors for LAD. The speedup gained by DVI rules can be up to two orders of magnitude.
Design of a parallel distributed fuzzy LQR controller for double-pendulum-type overhead cranes

One of the common industrial structures that are used widely in many harbors and factories and buildings is overhead crane. Overhead cranes are usually operated manually or by some conventional control methods. In this paper, we propose a hybrid controller includes both position regulation and anti-swing control. According to Takagi-Sugeno fuzzy model of an overhead crane, a fuzzy controller designed with parallel distributed compensation and Linear Quadratic Regulation. With the Takagi-Sugeno fuzzy modeling, the nonlinear system is approximated by the combination of several linear subsystems in the corresponding fuzzy state space region. Then by constructing a linear quadratic regulation subcontroller according to each linear subsystem, a parallel distributed fuzzy LQR controller is designed. Further, the stability of the overhead crane with the parallel distributed fuzzy LQR controller is discussed. Simulation results illustrated the validity of the proposed control algorithm and it is compared with a similar method parallel distributed fuzzy controller.
Abundances of Tetracycline, Sulphonamide and Beta-Lactam Antibiotic Resistance Genes in Conventional Wastewater Treatment Plants (WWTPs) with Different Waste Load

Antibiotics and antibiotic resistant bacteria enter wastewater treatment plants (WWTPs), an environment where resistance genes can potentially spread and exchange between microbes. Several antibiotic resistance genes (ARGs) were quantified using qPCR in three WWTPs of decreasing capacity located in Helsinki, Tallinn, and Tartu, respectively: sulphonamide resistance genes (sul1 and sul2), tetracycline resistance genes (tetM and tetC), and resistance genes for extended spectrum beta-lactams (blaoxa-58, blashv-34, and blactx-m-32). To avoid inconsistencies among qPCR assays we normalised the ARG abundances with 16S rRNA gene abundances while assessing if the respective genes increased or decreased during treatment. ARGs were detected in most samples; sul1, sul2, and tetM were detected in all samples. Statistically significant differences (adjusted p<0.01) between the inflow and effluent were detected in only four cases. Effluent values for blaoxa-58 and tetC decreased in the two larger plants while tetM decreased in the medium-sized plant. Only blashv-34 increased in the effluent from the medium-sized plant. In all other cases the purification process caused no significant change in the relative abundance of resistance genes, while the raw abundances fell by several orders of magnitude. Standard water quality variables (biological oxygen demand, total phosphorus and nitrogen, etc.) were weakly related or unrelated to the relative abundance of resistance genes. Based on our results we conclude that there is neither considerable enrichment nor purification of antibiotic resistance genes in studied conventional WWTPs.
Length-matching routing for high-speed printed circuit boards

As the clock frequencies used in industrial applications increase, the timing requirements imposed on routing problems become tighter. So, it becomes important to route the nets within tight minimum and maximum length bounds. Although the problem of routing nets to satisfy maximum length constraints is a well-studied problem, there exists no sophisticated algorithm in the literature that ensures that minimum length constraints are also satisfied. In this paper, we propose a novel algorithm that effectively incorporates the min-max length constraints into the routing problem. Our approach is to use a Lagrangian relaxation framework to allocate extra routing resources around nets simultaneously during routing them. We also propose a graph model that ensures that all the allocated routing resources can be used effectively for extending lengths. Our routing algorithm automatically prioritizes resource allocation for shorter nets, and length minimization for longer nets so that all nets can satisfy their min-max length constraints. Our experiments demonstrate that this algorithm is effective even in the cases where length constraints are tight, and the layout is dense.
On Families of Mutually Exclusive Sets

In this paper we shall be concerned with a certain particular problem from the general theory of sets, namely with the problem of the existence of families of mutually exclusive sets with a maximal power . It will turn out-in a rather unexpected way that the solution of these problems essentially involves the notion of the so-called "inaccessible numbers . " In this connection we shall make some general remarks regarding inaccessible numbers in the last section of our paper .
O ct 2 00 2 W-algebras for non-abelian Toda systems

We construct the classical W -algebras for some non-abelian Toda systems associated with the Lie groups GL 2n(R) and Spn(R). We start with the set of characteristic integrals and find the Poisson brackets for the corresponding Hamiltonian counterparts. The convenient block matrix representaion for the Toda equations is used. The infinitesimal symmetry transformations generated by the elements of the W -algebras are presented.
Using Deep Learning and Evolutionary Algorithms for Time Series Forecasting

Deep Learning is one of the latest approaches in the field of artificial neural networks. Since they were first proposed, Deep Learning models have obtained state-of-art results in some problems related to classification and pattern recognition. However, such models have been little used in time series forecasting. This work aims to investigate the use of some of these architectures in this kind of problem. Another contribution is the use of one Evolutionary Algorithm to optimize the hyperparameters of these models. The advantage of the proposed method is shown on two artificial time series datasets and one electricity load demand dataset.
Intelligent feedback control-based adaptive resource management for asynchronous, decentralized real-time systems

Presents intelligent feedback control techniques for adaptive resource management in asynchronous, decentralized real-time systems. We propose adaptive resource management techniques that are based on feedback control theory and are designed using the intelligent control design paradigm. The controllers solve resource allocation problems that arise during run-time adaptation using the classic proportional-integral-derivative (PID) control functions and fuzzy logic. We study the performance of the controllers through simulation. The simulation results indicate that the controllers produce low missed deadline ratios and resource utilizations during high-workload situations.
The Effect of Individualized Versus Standardized Parenteral Nutrition on Body Weight in Very Preterm Infants

Background This study was designed to evaluate whether standardizing total parenteral nutrition (TPN) is at least non-inferior to TPN with individualized composition in premature infants with a gestational age (GA) < 32 weeks. Methods In this retrospective cohort study, all preterm born in or transferred to Maxima Medical Center (MMC) within 24 hours after birth with a GA < 32 weeks were included. The individualized group (2011) was compared to the partially standardized group (2012) and completely standardized group (2014) consequently. The primary endpoint was difference in growth. Secondary endpoints included differences in electrolyte concentrations. Results A total of 299 preterm were included in this study. When comparing weight gain, the infants in the (partially) standardized group demonstrated significantly (P < 0.05) less weight loss during the first days of life and grew faster subsequently in the following days than the individualized TPN regimen. Furthermore, significant differences in abnormal serum sodium, chloride, calcium, creatinine, magnesium and triglycerides values were demonstrated. Conclusion TPN with a (partially) standardized composition revealed to be at least non-inferior to TPN with an individualized composition.
A novel MAC protocol for throughput optimization over IEEE 802.11 ad hoc networks

This paper presents a novel media access control (MAC) mechanism for IEEE 802.11 ad hoc networks, where a station will start a virtual contention process before every data packet from upper layer is forwarded to 802.11 MAC layer. By choosing the optimal size of virtual contention window for the specified network scenario (i.e., the number of stations and 802.11 MAC parameters), the maximum throughput of system can be achieved, which is validated by analytical model. Our scheme is very simple for practical deploying because there are no modifications required on IEEE802.11 hardware.
Cortical efferents of the perirhinal, postrhinal, and entorhinal cortices of the rat

We investigated the cortical efferents of the parahippocampal region by placing injections of the anterograde tracers, Phaseolus vulgaris‐leuccoagglutinin, and biotinylated dextran amine, throughout the perirhinal (PER), postrhinal (POR), and entorhinal cortices of the rat brain. The resulting density of labeled fibers was evaluated in 25 subregions of the piriform, frontal, insular, temporal, cingulate, parietal, and occipital areas. The locations of labeled terminal fibers differed substantially depending on whether the location of the injection site was in PER area 35, PER area 36, POR, or the lateral or the medial entorhinal (LEA and MEA). The differences were greater for sensory regions. For example, the POR efferents preferentially target visual and spatial regions, whereas the PER efferents target all sensory modalities. The cortical efferents of each region largely reciprocate the cortical afferents, though the degree of reciprocity varied across originating and target regions. The laminar pattern of terminal fibers was consistent with the notion that the efferents are feedback projections. The density and amount of labeled fibers also differed substantially depending on the regional location of injection sites. PER area 36 and POR give rise to a greater number of heavy projections, followed by PER area 35. LEA also gives rise to widespread cortical efferents, arising mainly from a narrow band of cortex adjacent to the PER. In contrast, the remainder of the LEA and the MEA provides only weak efferents to cortical regions. Prior work has shown that nonspatial and spatial information is transmitted to the hippocampus via the PER‐LEA and POR‐MEA pathways, respectively. Our findings suggest that the return projections follow the same pathways, though perhaps with less segregration. © 2009 Wiley‐Liss, Inc.
Neural Field Model of Receptive Field Restructuring in Primary Visual Cortex

Receptive fields (RF) in the visual cortex can change their size depending on the state of the individual. This reflects a changing visual resolution according to different demands on information processing during drowsiness. So far, however, the possible mechanisms that underlie these size changes have not been tested rigorously. Only qualitatively has it been suggested that state-dependent lateral geniculate nucleus (LGN) firing patterns (burst versus tonic firing) are mainly responsible for the observed cortical receptive field restructuring. Here, we employ a neural field approach to describe the changes of cortical RF properties analytically. Expressions to describe the spatiotemporal receptive fields are given for pure feedforward networks. The model predicts that visual latencies increase nonlinearly with the distance of the stimulus location from the RF center. RF restructuring effects are faithfully reproduced. Despite the changing RF sizes, the model demonstrates that the width of the spatial membrane potential profile (as measured by the variance of a gaussian) remains constant in cortex. In contrast, it is shown for recurrent networks that both the RF width and the width of the membrane potential profile generically depend on time and can even increase if lateral cortical excitatory connections extend further than fibers from LGN to cortex. In order to differentiate between a feedforward and a recurrent mechanism causing the experimental RF changes, we fitted the data to the analytically derived point-spread functions. Results of the fits provide estimates for model parameters consistent with the literature data and support the hypothesis that the observed RF sharpening is indeed mainly driven by input from LGN, not by recurrent intracortical connections.
Global Mild Solution for a Chemotaxis-Haptotaxis Model of Tumor Invasion

This paper deals with a mathematical model of tumor invasion developed by Chaplain and Lolas. Besides random motion, the tumor cells are directed not only by haptotaxis (cellular locomotion directed in response to a concentration gradient of adhesive molecules along extracellular matrix) but also by chemotaxis (cellular locomotion directed in response to a concentration gradient of the diffusible proteolytic enzyme). The existence of unique global mild solution is proved using the theory of fractional powers of analytic semigroup generators.
Five Decades in Probability and Statistics

Plan 1. Linnik and creation of the Leningrad school 2. Linnik’s students 3. 1951 4. Unimodal distributions 5. Classical limit theorems a) moment conditions for given convergence rate b) fast convergence rates in CLT c) Chebyshev-Cramér asymptotic expansions 6. Weak dependence a) uniform mixing condition b) central limit theorem under uniform mixing condition c) continued fractions d) central limit theorem for martingale differences e) book: Ibragimov and Linnik 7. Spectral theory of random processes a) Toeplitz matrices b) total regularity c) book: Ibragimov and Rozanov 8. Functionals of random walk a) St-Flour lectures b) book: Borodin and Ibragimov 9. Smoothness of sample paths 10. Zeros of random polynomials 11. Statistical estimation a) normality of estimates in parametric models b) sequential estimation c) estimation in white noise model d)book: Ibragimov and Khasminskii e) estimation in nonparametric models 12. Recent works a) almost sure limit theorems b) estimation of SPDE coefficients 13. Ibragimov’s students 14. Awards
Chemical Compositions, Chromatographic Fingerprints and Antioxidant Activities of Andrographis Herba

This paper describes the development of an HPLC-UV-MS method for quantitative determination of andrographolide and dehydroandrographolide in Andrographis Herba and establishment of its chromatographic fingerprint. The method was validated for linearity, limit of detection and quantification, inter- and intra-day precisions, repeatability, stability and recovery. All the validation results of quantitative determination and fingerprinting methods were satisfactory. The developed method was then applied to assay the contents of andrographolide and dehydroandrographolide and to acquire the fingerprints of all the collected Andrographis Herba samples. Furthermore, similarity analysis and principal component analysis were used to reveal the similarities and differences between the samples on the basis of the characteristic peaks. More importantly, the DPPH free radical-scavenging and ferric reducing capacities of the Andrographis Herba samples were assayed. By bivariate correlation analysis, we found that six compounds are positively correlated to DPPH free radical scavenging and ferric reducing capacities, and four compounds are negatively correlated to DPPH free radical scavenging and ferric reducing capacities.