Stochastic controller as an active queue management based on B-spline kernel observer via particle swarm optimization

Given the fact that the current Internet is getting more difficult in handling the traffic congestion control, the proposed method is compatible with the stochastic nature of network dynamics. Most conventional active queue management is based on the first stochastic moment. In stochastic theory, the first moment is not efficient for non-Gaussian systems that are the same as the network queue size. We propose a new stochastic active queue management technique, based on stochastic control and B-spline window observer, called intelligent probability density function AQM (IPDF-AQM). The IPDF-AQM is based on a PDF control and particle swarm optimization, which not only considers the average queue length at the current time slot, but also takes into consideration the PDF of queue lengths within a round-trip time. We provide a guideline for the selection of the probability of dropping as control input for TCP/AQM system to make the PDF of queue length converge at a certain PDF target based on B-spline approximation and improve the network performance. Simulation results show that the proposed stochastic AQM scheme does improve the end-to-end performance.     

Green information systems use in social enterprise: the case of a community-led eco-localization website in the West Midlands region of the UK

This study examines the intention of environmentally-oriented social enterprises to continue using Green IS (an eco-localization website here) in Herefordshire located in the West Midlands region of the United Kingdom. The Herefordshire Greenlinks (HGL) Association is a local business community that operates primarily through the HGL Website in order to help local social enterprises find and trade local eco-friendly goods and services. It is an example of a “market-based” approach to solving social and environmental issues that is inspired by a bottom-up view of community development and eco-localization. Based on the theory of uses and gratification of media use and the new environmental paradigm, we propose a research model that outlines the various factors contributing to intention to continue using an eco-localization website. The research model and its associated hypotheses were empirically tested using a dataset generated from a survey of 83 small social enterprises. The results demonstrate the importance of three different types of gratification – content, social and performance gratification as well as users’ environmental concerns in determining the intention to continue using an eco-localization website. This study contributes to the Green IS literature by extending research to the social sector environment, and it also provides practical insight for designers of such community-led eco-localization websites.     

Simultaneous determination of pyruvate and acetate levels in xanthan biopolymer by infrared spectroscopy: effect of spectral pre-processing for solid-state analysis

A rapid, direct, and reagent-free procedure based on solid-state Fourier transform infrared spectroscopy (FT-IR) coupled with partial least squares (PLS) data analysis has been developed for simultaneous determination of pyruvate and acetate levels in a microbial xanthan biopolymer. The influences of various spectral pre-processing procedures were studied in order to eliminate effects caused by sample preparation. It was determined that the combination of first derivative and orthogonal signal correction pre-processing contributes to a significant increase in the predictive performance of PLS-1 regression models. By employing the wavenumber region 1320–1350 cm⁻¹ for pyruvate determination and 1500–1600 cm⁻¹ for acetate determination, the root mean square error of cross-validation (RMSECV) for pyruvate and acetate contents were obtained 0.13% and 0.29% w/w, respectively. Results of the proposed procedure for different real samples and those obtained by their reference methods were compared.     

Senior managers’ perception on green information systems (IS) adoption and environmental performance: Results from a field survey

Based on a Belief-Action-Outcome framework, we produced a model that shows senior managers’ perception of both the antecedents to and the consequences of Green IS adoption by a firm. This conceptual model and its associated hypotheses were empirically tested using a dataset generated from a survey of 405 organizations. The results suggest that coercive pressure influences the attitude toward Green IS adoption while mimetic pressure does not. In addition, we found that there was a significant relationship between Green IS adoption, attitude, and consideration of future consequences. Finally, we found that only long term Green IS adoption was positively related to environmental performance.     

Additives to prevent the formation of surface defects during poly(vinyl chloride) calendering

Gas checks are visible fleck-shaped defects that occur on the surface of poly(vinyl chloride) (PVC) films during industrial calendering. Films containing these surface defects often do not meet minimum product specifications and therefore must be disposed of or recycled, resulting in increased cost and material waste. Currently, gas checks are controlled by keeping film gauge low and through trial-and-error modifications of processing parameters by calender operators. In this work, our group developed a series of chemical additives that can be blended with PVC to prevent the formation of gas check defects. We found that a series of poly(caprolactone) (PCL)-based compounds with diester linkers and alkyl chain cappers were all effective at preventing the formation of gas checks during calendering, with additive concentrations as low as 8 phr producing films with no gas checks. We found that the blends produced with our additives had higher melt viscosities than those produced with additives that do not remove gas checks, suggesting that viscosity plays an important role in preventing gas check defects.     

Removal of toxic nitrate ions from drinking water using conducting polymer/MWCNTs nanocomposites

New application of conducting polymers as stable nanocomposites for nitrate ion exchange materials in water and wastewater treatment and for environmental protection is introduced in this work. The nanocomposites of multi-walled carbon nanotubes (MWCNTs) with different polymers such as: polyaniline (PANI), polypyrrole (PPY), poly(1,8-diaminonaphthalene) [P(1,8-DAN)] and poly(2-vinylpyridine) (P2VP) were synthesized with different dopants as effective and reusable nanocomposites for nitrate removal from drinking water. Nitrate anions at toxic concentrations were removed from water using ion exchange mechanism without any toxic byproducts. The obtained results demonstrate that effective ion exchange occurs between NO₃ ^? and Cl^?. There are some protonated heteroatoms in polymer chains that are bonded with anions of dopants and their counter ions in nanocomposites. These dopant anions on the =NH⁺– groups of polymers can be exchanged with NO₃ ^? in water. Adsorption of NO₃ ^? on polymer/MWCNTs nanocomposites showed dependency to some parameters. Different experimental parameters such as pH and temperature of the sample, polymers dopant, and the ratio of polymer to MWCNTs in nanocomposites affect the amount of nitrate removal. The highest removal efficiency was achieved at 1.20 g L^?1 of PANI/MWCNTs (3:1) nanocomposite, pH = 6.5 and ambient temperature. After five successive cycles of nitrate removal, this parameter was still up to 70 % compared to the first run (up to 80 %).     

From enabling to levelling: the need to change the policy rationale of the intermediary liability regime

On the spectrum of policy formulation, the current intermediary liability regime is strongly rooted in the extreme end of policy formulation. The main focus of this policy choice is to provide an ‘enabling’ governance structure. Other options, such as providing a level playing field or exploring how and to what extent the intermediary liability regime will need to even constrain undesired digital behaviour, have hardly been given consideration. The immunities granted under the intermediary liability regime have hence successfully enabled novel business models and assured freedom of expression on the internet, leaving, however, significantly declining investment rates in music an unaddressed policy issue. According to estimates of this study, the cumulative investments lost in the UK, Germany and France alone amounted to up to nearly 4 billion Euro between 2008 and 2014. For the European Union, this situation posits a challenge with important ramifications in the long run. If Europe continues to lose out on investments in creative content, it risks losing its international competitiveness. It is thus proposed to revisit the underlying policy rationale of the intermediary liability regime and explore what steps are needed to provide a more equal level playing field for all types of market participants, be they the traditional music industry or novel forms of online intermediaries.     

MOSFET栅氧泄漏隧穿电流的分析模型:量子力学研究(英文)

研发了一种通过MOSFET的超薄栅氧化物分析直接隧穿电流密度的模型。采用Wentzel-Kramers-Brilliouin(WKB)近似计算了隧穿概率,利用清晰的表面势方程改进模型的准确性。在研究模型中考虑了Si衬底中反型层的量子化和多晶硅栅耗尽,还研究了多晶硅掺杂对栅氧化层隧穿电流的影响。仿真结果表明,栅氧化层隧穿电流随多晶硅栅掺杂浓度的增加而增加。该结论与已报道的结果相吻合,从而证明了该模型的正确性。