Digital image steganalysis based on the reciprocal singular value curve

Embedding secret messages in steganographic approaches is similar to adding some weak noises to the original media. One of the traditional ways for image steganalysis is computing a feature sets using noise residuals. From another perspective, the disturbance of natural image statistics can be explored to extract the feature vector for steganalysis. In fact, the alteration of natural scene statistics can be investigated to reveal the presence of secret messages embedded in images. Hence, the feature vectors can be constructed using such changes. In the proposed scheme, the alteration of singular value curve is used to construct the steganalysis feature vector. Two spatial and JPEG based feature vectors are extracted in the proposed statistical exploitation. The experimental results illustrate the acceptable performance of the proposed feature vectors for both universal and JPEG based steganalysis methods.

     

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.     

Stiction reduction processes for surfacemicromachines

We present a review of surface micromachining technology with anemphasis on polycrystalline silicon (polysilicon)microstructures. The problems of release-related and in-usestiction are then introduced along with a brief review ofvarious approaches developed for reducing them. These includesurface roughening and chemical modification of the siliconsurfaces. The constraints that post-release back-end processessuch as assembly and packaging place on surface treatments aredescribed in general. Finally, we briefly outline some of theimportant scientific and technological issues that remain to be clarified in stiction phenomena in micromechanical structures.     

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.     

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.     

Investigation on hydrophilicity of micro-arc oxidized TiO2 nano/micro-porous layers

Titania porous layers with a rough surface were synthesized via micro-arc oxidation (MAO) and the effect of the applied voltage and electrolyte concentration on surface structure, and chemical composition of the layers was studied. Morphological and topographical investigations, performed by SEM and AFM, revealed that pore size and surface roughness of the layers increased with the applied voltage and the electrolyte concentration. Based on the XRD and XPS results, the grown layers consisted of anatase and rutile phases with varying fractions depending on growth conditions. It was found that anatase/rutile relative content reached its maximum value at medium applied voltages or electrolyte concentrations. Finally, hydrophilicity of the grown layers was determined using a water contact angle apparatus, and a correlation between measured contact angles and MAO-parameters was suggested. It was observed that the layers synthesized under the applied voltage of 400 V in the electrolytes with a concentration of 10 g l⁻¹ exhibited the highest hydrophilicity.     

Effect of temperature on in-use stiction of cantilever beams coated with perfluorinated alkysiloxane monolayers

The effect of annealing (for temperatures up to 300 /spl deg/C) on the antistiction performance of perfluorinated self-assembled monolayers (SAMs) is characterized using polycrystalline Si cantilever beam arrays. The monolayers 1H,1H,2H,2H, perfluorodecyltrichlorosilane (FDTS) and 1H,1H,2H,2H, perfluorodecyldimethylchlorosilane (FDDMCS) deposited from both liquid and vapor phase are investigated. It is observed that stiction decreases upon annealing for both monolayers and for both types of deposition. FDTS, however, displays greater temperature stability than FDDMCS regardless of the mode of deposition. The higher thermal resistance of the FDTS underscores the importance of monolayer crosslinking since unlike FDDMCS, FDTS forms a siloxane network on the surface. Further vacuum annealing and X-ray photoelectron spectroscopy experiments are performed to identify chemical changes in the monolayer during annealing. Incipient monolayer degradation is observed, with loss of the whole fluorinated monolayer chain. This process appears drastically different from the decomposition mechanism of hydrogenated alkylsiloxane monolayers such as octadecyltrichlorosilane (OTS).     

Recent progress toward a manufacturable polycrystalline SiC surface micromachining technology

In this paper, we present results of recent research from our laboratory directed toward a manufacturable SiC surface micromachining technology for microelectromechanical systems (MEMS) applications. These include the development of a low-pressure chemical vapor deposition and in situ doping processes for silicon carbide (SiC) films at relatively low temperatures, as well as the development of selective dry etching processes for SiC using nonmetallic masking materials. Doped polycrystalline SiC films are deposited at 800/spl deg/C by using a precursor 1,3-disilabutane and dopant gas NH/sub 3/, with the minimum resistivity of 26 m/spl Omega//spl middot/cm. Dry etching for SiC and its selectivity toward silicon dioxide and silicon nitride masking materials are investigated using SF/sub 6//O/sub 2/, HBr, and HBr/Cl/sub 2/ transformer coupled plasmas. The etch rate, etch selectivity, and etch profile are characterized and compared for each etch chemistry. By combining the LPCVD and dry etching process with conventional microfabrication technologies, a multiuser SiC MEMS process is developed.