Improving online learning activity interoperability with Acos server

Modern online learning management systems (LMSs) support a variety of online learning activities, such as animations, exercises, and other interactive learning materials. However, there are many technical challenges in using the same activities in multiple LMSs because content is typically tightly coupled with one protocol to communicate with the LMS and different LMSs use different protocols for launching activities and receiving grades. This leads to low reusability of learning activities and similar content being developed in multiple places. To overcome these issues, we present Acos, a smart learning content server, which emphasizes the reusability of online learning activities by decoupling the content and existing interoperability protocols. It allows integrating the same learning activities into multiple LMSs using different protocols by providing a uniform interface for learning activities. Adapting this architecture allows instructors to choose activities based on pedagogical goals instead of letting technical restrictions of LMSs dictate the content selection process. Copyright © 2017 John Wiley & Sons, Ltd.     

A stable bilinear element for the Reissner-Mindlin plate model

In this paper, we introduce a new quadrilateral element using isoparametric bilinear basis functions for both components of the rotation vector and the deflection. The element is a stable modification of the MITC4 element. We report on calculations with this new element, the original MITC4 and also the bilinear element, with selective reduced integration. The numerical results are in accordance with the results of the numerical analysis and they show that (i) the method with reduced integration is highly unreliable and cannot be recommended; (ii) the MITC4 performs rather well, but its instability can lead to a decrease in accuracy for the deflection and especially to an inaccurate and oscillating shear force; (iii) the drawbacks of the MITC4 are not present in the modified method.     

The Effect of a Fish Oil and/or Probiotic Intervention from Early Pregnancy Onwards on Colostrum Immune Mediators: A Randomized,Placebo-Controlled,Double-Blinded Clinical Trial in Overweight/Obese Mothers

Scope

Modifying the composition of colostrum by external factors may provide opportunities to improve the infant's health. Here, we evaluated how fish oil and/or probiotics supplementation modify concentrations of colostrum immune mediators and their associations with perinatal clinical factors on mothers with overweight/obesity.

Methods and results

Pregnant women were randomized in a double-blind manner into four intervention groups, and the supplements were consumed daily from early pregnancy onwards. Colostrum samples were collected from 187 mothers, and 16 immune mediators were measured using bead-based immunoassays. Interventions modified colostrum composition; the fish oil+probiotics group had higher concentrations of IL-12p70 than probiotics+placebo and higher FMS-like tyrosine kinase 3 ligand (FLT-3L) than fish oil+placebo and probiotics+placebo (one-way analysis of variance, post-hoc Tukey's test). Although the fish oil+probiotics group had higher levels of IFNα2 compared to the fish oil+placebo group, these differences were not statistically significant after correction for multiple testing. Multivariate linear model revealed significant associations between several immune mediators and the perinatal use of medication.

Conclusion

Fish oil/probiotics intervention exerted a minor effect on concentrations of colostrum immune mediators. However, medication during the perinatal period modulated the immune mediators. These changes in colostrum's composition may contribute to immune system development in the infant.     

Use of partially shrouded impeller in a small centrifugal compressor

Numerical analysis is conducted for the 3-dimensional impeller and vaneless diffuser of a small centrifugal com- pressor. The influence of impeller tip clearance on the flow field of the impeller is investigated. Detailed investigation on the leaking flow across the tip clearance of the impeller shows that the leaking flow rate is higher near the exit of the impeller than that near the inlet of the impeller. Based on this phenomenon, a new partially shrouded impeller is designed. The impeller is shrouded near the exit of the impeller. Numerical results show that the secondary flow region becomes smaller at the exit of the impeller. Better performance is achieved than that with the unshrouded impeller.     

Unsteady Pressure Field in a Vaneless Diffuser of a Centrifugal Compressor: An Experimental and Computational Analysis

Unsteady static pressure was measured and time-accurate numerical simulations were conducted in order to analyze unsteady behaviour of the centrifugal compressor diffuser. The unsteady static pressure was measured at the diffuser inlet and outlet at three different circumferential positions. Operation points near the surge, the design operation point and operation point near the choke were used in measurements. The time-accurate simulations were conducted at the design operation point and operation point near the choke. The whole compressor was modelled and the low Reynolds number k-εturbulence model was utilized in numerical simulations. The gathered numerical and experimental unsteady pressures were compared with each other.     

Effect of high negative incidence on the performance of a centrifugal compressor stage with conventional vaned diffusers

Three vaned diffusers, designed to have high negative incidence (-8°) at the design operating point, are studied experimentally. The overall performance (efficiency and pressure ratio) are measured at three rotational speeds, and flow angles before and after the diffuser are measured at the design rotational speed and with three mass flow rates. The results are compared to corresponding results of the original vaneless diffuser design. Attention is paid to the performance at lower mass flows than the design mass flow. The results show that it is possible to improve the performance at mass flows lower than the design mass flow with a vaned diffuser designed with high negative incidence. However, with the vaned diffusers, the compressor still stalls at higher mass flow rates than with the vaneless one. The flow angle distributions after the diffuser are more uniform with the vaned diffusers.     

Reversible surface binding of cadmium and lead by lactic acid and bifidobacteria

Extensive cadmium and lead contamination of water has been reported to occur locally as a result of human activities. Lactic acid bacteria have been reported to remove cadmium and lead from water. The aim of this work was to clarify the mechanisms of cadmium and lead removal from water. In addition, the effect of other metals, reversibility of binding and recyclability of the biomass was assessed. Based on our earlier data, the two most promising lactic acid bacteria, Lactobacillus fermentum ME3 and Bifidobacterium longum 46, were selected for these experiments. The results showed that the presence of other cationic metals and blocking of carboxyl and phosphoryl groups reduced cadmium and lead removal. These results suggest involvement of electrostatic interactions in cadmium and lead removal, and support our earlier findings. Transmission electron micrographs showed large deposits of lead on the bacterial surface suggesting formation of metallic lead precipitates. Both cadmium and lead removal were reversible processes established by full recovery of removed metal after desorption with dilute solutions of EDTA and HNO(3). Resorption capacity of both biomasses tested was reduced after regeneration with 10 mM EDTA and 15 mM HNO(3). Taken together, the results suggest involvement of several reversible mechanisms such as ion exchange and precipitation in cadmium and lead binding by lactic acid bacteria. The results show that specific lactic acid bacteria have the potential for removal of cadmium and lead from water although reduction in resorption capacity after regeneration of the biomass may form a problem. Since the studies so far have mainly focused on removal of single metals from pure water, metal removal in conditions of natural waters should be assessed in further experiments.     

Parallel Memory Architecture for Application-Specific Instruction-Set Processors

Many of the current applications used in battery powered devices are from digital signal processing, telecommunication, and multimedia domains. These applications typically set high requirements for computational performance and often parallelism is the key solution to meet the performance requirements. In order to exploit the parallel processing units, memory should be able to feed the data path with data. This calls for a memory organization supporting parallel memory accesses. In this paper, a conflict resolving parallel data memory system for application-specific instruction-set processors is described. The memory structure is generic and reusable to support various application-specific designs. The proposed memory system does not employ any predefined access format signals for memory addressing. The proposed parallel memory system is attached to an application-specific instruction-set processor core and comparison on area, power, and critical path are shown. The experiments show that significant power savings can be obtained by exploiting the parallel memory system instead of multi-port memory.

UWB radio module design for wireless sensor networks

In this paper, we describe an impulse-based ultra wideband (UWB) radio system for wireless sensor network (WSN) applications. Different architectures have been studied for base station and sensor nodes. The base station node uses coherent UWB architecture because of the high performance and good sensitivity requirements. However, to meet complexity, power and cost constraints, the sensor module uses a novel non-coherent architecture that can autonomously detect the UWB signals. The radio modules include a transceiver block, a baseband processing unit and a power management block. The transceiver block includes a Gaussian pulse generator, a multiplier, an integrator and timing circuits. For long range applications, a wideband low noise amplifier (LNA) is included in the transceiver of the sensor module, whereas in short range applications it is simply eliminated to further reduce the power consumption. In order to verify the proposed system concept, circuit level implementation is studied using 1.5 V 0.18 μm CMOS technology. Finally, the UWB radio modules have been designed for implementation in liquid-crystal-polymer (LCP) based System-on-Package (SoP) technology for low power, low cost and small size integration. A small low cost, double-slotted, Knight’s helm antenna is embedded in the LCP substrate, which shows stable characterization and a return loss better than ?10 dB over the UWB band.