Sensitivities to early exchange in synchronous computer-supported collaborative learning (CSCL) groups

This study reports the impact of high sensitivity to early exchange in 11th-grade, CSCL triads solving well- and ill-structured problems in Newtonian Kinematics. A mixed-method analysis of the evolution of participation inequity (PI) in group discussions suggested that participation levels tended to get locked-in relatively early on in the discussion. Similarly, high (low) quality member contributions made earlier in a discussion did more good (harm) than those made later on. Both PI and differential impact of member contributions suggest a high sensitivity to early exchange; both significantly predicting the eventual group performance, as measured by solution quality. Consequently, eventual group performance could be predicted based on what happened in the first 30–40% of a discussion. In addition to drawing theoretical and methodological implications, implications for scaffolding CSCL groups are also discussed.     

Dynamics of growth and weight transitions in a pediatric cohort from India

Background  

There is paucity of information regarding time trends of weight status in children from rapidly developing economies like India. The aim of the study was to analyse the dynamics of growth and weight transitions in a cohort of school children from India.     

Corrigendum Static Frequency Assignment in Cellular Networks

Abstract. No abstract.     

Computer-aided materials processing for silicon diffused impurity bipolar-circuit technology

A computer study has been made to infer materials processes for bipolar integrated circuits. The scheme is based on relatively simple device terminal measurements and microphotography. These yield final process parameters such as diffusion temperatures and times, oxide thicknesses and the other processing conditions. Thus, several intermediate process steps, required to obtain desirable device properties, can be eliminated once a prototype has been obtained and batch runs are planned.     

Phase assignment for synthesis of low-power domino circuits

High performance circuit techniques such as domino logic have migrated from the microprocessor world into more mainstream ASIC designs but domino logic comes at a heavy cost in terms of total power dissipation. A set of results related to automated phase assignment for the synthesis of low-power domino circuits is presented: (1) it is demonstrated that the choice of phase assignment at the primary outputs of a circuit can significantly impact lower dissipation in the domino block, and (2) a method to determine a phase assignment that minimises power consumption in the final circuit implementation is proposed. Preliminary experimental results on a mixture of public domain benchmarks and real industry circuits show potential power savings as high as 34% over the minimum area realisation of the logic. Furthermore, the low-power synthesised circuits still meet timing constraints     

Performance analysis of the segment npn anode LIGBT

The performance of a high-voltage lateral insulated gate bipolar transistor (LIGBTs) with segmented n+p/n anode fabricated in junction isolation technology is experimentally investigated at both room and elevated temperatures. Detailed two dimensional numerical modeling of a vertical representation of the structure shows that significant electron current passes through the n/sup +/p/n segment of the anode region during the on-state and when devices are subjected to clamped inductive switching. It is shown that the magnitude of electron current can be controlled by modifying the p-base charge which enables enhancement of the turn-off loss/forward voltage drop tradeoff in comparison to conventional LIGBTs.     

Doppler estimation using a coherent ultrawide-band random noiseradar

The University of Nebraska has developed an ultrawide-band (UWB) coherent random noise radar operating over the 1-2 GHz frequency range. The system achieves phase coherence by using heterodyne correlation of the received signal with a time-delayed frequency-shifted replica of the transmit waveform. Knowledge of the phase of the received signal and its time dependence due to target motion permits the extraction of the mean Doppler frequency from which the target speed can be inferred. Theoretical analysis, simulation studies, and laboratory measurements using a microwave delay line showed that it was possible to estimate the Doppler frequency from targets with linear as well as rotational motion. Field measurements using a photonic delay line demonstrated the success of this technique at a range of about 200 m at target speeds of up to 9 m/s. Analysis shows that the accuracy with which the Doppler frequency can be estimated depends not only on the phase performance of various components within the system, but also upon the random nature and bandwidth (BW) of the transmit waveform, and the characteristics of unsteady target motion     

Volatile aroma compounds of raw and roasted palm kernel

The volatile aroma compounds of raw and roasted palm kernel, isolated by hydrodistillation, were analysed by g.l.c. and g.c.-m.s. A number of compounds have been identified for the first time in this commodity. It was found that δ-lactones and ethyl esters were predominant in the flavour profile. In roasted palm kernels, flavour analysis showed the presence of a number of pyrazines formed during heating. Most of the lactones and esters identified in raw palm kernel were present in the roasted samples also. The flavour concentrate included a number of fatty acids in both the raw and roasted samples, in small amounts.