700 research outputs found
Evaluating and improving adaptive educational systems with learning curves
Personalised environments such as adaptive educational systems can be evaluated and compared using performance curves. Such summative studies are useful for determining whether or not new modifications enhance or degrade performance. Performance curves also have the potential to be utilised in formative studies that can shape adaptive model design at a much finer level of granularity. We describe the use of learning curves for evaluating personalised educational systems and outline some of the potential pitfalls and how they may be overcome. We then describe three studies in which we demonstrate how learning curves can be used to drive changes in the user model. First, we show how using learning curves for subsets of the domain model can yield insight into the appropriateness of the model’s structure. In the second study we use this method to experiment with model granularity. Finally, we use learning curves to analyse a large volume of user data to explore the feasibility of using them as a reliable method for fine-tuning a system’s model. The results of these experiments demonstrate the successful use of performance curves in formative studies of adaptive educational systems
The e!ects of a non-intervention HACCP implementation on process hygiene indicators on bovine and porcine carcasses
Four sites on each of 720 dressed carcasses (360 bovine and 360 porcine) were sampled (2,880 samples in total) in a single commercial
abattoir slaughtering cattle and pigs using two separate slaughterlines. The carcasses were sampled before HACCP (pre-HACCP;
960 samples) and after HACCP implementation (post-HACCP; 1,920 samples) and Total Viable Count (TVC), Enterobacteriaceae count
(EC) and Salmonella spp. prevalence were determined. During the pre-HACCP period, mean TVC levels on four tested sites varied on
bovine carcasses between 3.03 and 4.19 log10 cfu/cm2 and on porcine carcasses between 3.73 and 3.99 log10 cfu/cm2. During the
post-HACCP period, TVC levels on all tested sites on carcasses were further signicantly reduced, by 0.33-1.64 log and 1.13-2.04 log
on bovine and porcine carcasses, respectively, compared to the pre-HACCP period. Both the EC occurrence in samples and EC levels in
EC-positive samples somewhat decreased during post-HACCP as compared to pre-HACCP period, but the reductions were not statistically
signicant due to large proportion of EC-negative samples and very low counts in EC-positive samples. Salmonella spp. was not
detected in any of bovine or porcine carcass samples, regardless of whether they were taken pre- or post-HACCP. Overall, the processhygiene-
improving eects of non-intervention HACCP have been proven through reduction of TVC on carcasses, but could not be
veried in the present study through similar reductions in EC and/or Salmonella, because of their low levels and/or absence
COMMUNICATION ACROSS ACCESS TECHNOLOGIES WITH APPLICATION-SPECIFIC POP SELECTION IN SOFTWARE-DEFINED ENTERPRISE FABRIC
Techniques are presented herein that add to the existing 3rd Generation Partnership Project (3GPP) fifth generation (5G), private 5G, and secure access service edge (SASE) connectivity options for remote hosts when such hosts are located in an enterprise software-defined access (SDA) network. The techniques aid in connecting remote terrain, Industry 4.0, Internet of things (IoT), and private 5G devices through enterprise SDA/SDN networks (or any other intermediary overlay networks) and provide inter-access technology communication between 5G and existing access technology endpoints in an enterprise SDA fabric. The techniques also bring point of presence (PoP) service-level agreement (SLA) information (such as latency measures, performance details, etc.) to an edge or access element of a network to facilitate 5G application-specific PoP selection and a redirection of traffic to the correct PoP. That information may be used to select an application-specific PoP exit which meet applicable SLA requirements and/or select a service using a particular border, and then select a specific PoP, thus meeting the SLA requirements. The techniques also augment a security solution when a physical firewall is not directly connected to the service border but, rather, is available as a 5G application, such as under a firewall as a service paradigm in a SASE environment
Toxicity and bioaccumulation of two non-protein amino acids synthesised by cyanobacteria, β-N-Methylamino-L-alanine (BMAA) and 2,4-diaminobutyric acid (DAB), on a crop plant.
In order to study the toxicity of the cyanobacterial non-protein amino acids (NPAAs) L-β-N-methylamino-L-alanine (BMAA) and its structural isomer L-2,4-diaminobutyric acid (DAB) in the forage crop plant alfalfa (Medicago sativa), seedlings were exposed to NPAA-containing media for four days. Root growth was significantly inhibited by both treatments. The content of derivatised free and protein-bound BMAA and DAB in seedlings was then analysed by LC-MS/MS. Both NPAAs were detected in free and protein-bound fractions with higher levels detected in free fractions. Compared to shoots, there was approximately tenfold more BMAA and DAB in alfalfa roots. These results suggest that NPAAs might be taken up into crop plants from contaminated irrigation water and enter the food chain. This may present an exposure pathway for NPAAs in humans
Intelligent and adaptive tutoring for active learning and training environments
Active learning facilitated through interactive and adaptive learning environments differs substantially from traditional instructor-oriented, classroom-based teaching. We present a Web-based e-learning environment that integrates knowledge learning and skills training. How these tools are used most effectively is still an open question. We propose knowledge-level interaction and adaptive feedback and guidance as central features. We discuss these features and evaluate the effectiveness of this Web-based environment, focusing on different aspects of learning behaviour and tool usage. Motivation, acceptance of the approach, learning organisation and actual tool usage are aspects of behaviour that require different evaluation techniques to be used
Two-dimensional XY spin/gauge glasses on periodic and quasiperiodic lattices
Via Monte Carlo studies of the frustrated XY or classical planar model we
demonstrate the possibility of a finite (nonzero) temperature spin/gauge glass
phase in two dimensions. Examples of both periodic and quasiperiodic two
dimensional lattices, where a high temperature paramagnetic phase changes to a
spin/gauge glass phase with the lowering of temperature, are presented. The
existence of the spin/gauge glass phase is substantiated by our study of the
temperature dependence of the Edwards-Anderson order parameter, spin glass
susceptibility, linear susceptibility and the specific heat. Finite size
scaling analysis of spin glass susceptibility and order parameter yields a
nonzero critical temperature and exponents that are in close agreement with
those obtained by Bhatt and Young in their random Ising model study
on a square lattice. These results suggest that certain periodic and
quasiperiodic two-dimensional arrays of superconducting grains in suitably
chosen transverse magnetic fields should behave as superconducting glasses at
low temperatures.Comment: RevTex, 25 pages. 11 epsf figures available upon request
([email protected] or [email protected]). Submitted
to Phys. Rev.
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