Privacy within pervasive communications

In the era of “anywhere, anytime communication”, contextual security is becoming very important. Context security means preventing leakage of information about such aspects of communication as identities of the parties involved, their locations, frequency and the times of communications, and so on as opposed to content security which is concerned with protecting the transmitted data against eavesdropping and manipulation and is usually achieved using encryption and message digests. Routing protocols play an important role in this regard. All of the previously proposed solutions in this area are based on reactive routing. In this paper, we propose a solution called V-routing based on proactive routing protocols for ad hoc networks of the type Mesh and MANET that conceals the locations and the identities of the communicating parties as well as the fact that they are communicating. Our protocol resists an omni-present eavesdropper that tries to locate and identify the source and the destination of a data flow. V-routing is especially capable of hiding the destination, unlike many other secure routing protocols, because it is designed according to a novel routing paradigm that puts the destination in charge of how packets should be sent to it.     

Investigations on landmine detection by BF3 detector

Experiments were carried out to investigate the possible use of neutron backscattering for the detection of polyethylene (PE) sample buried in the soil. In detection of landmine by neutrons, the neutron detector and its shield play an important role. In this paper, the effects of graphite, heavy water, polyethylene and boric acid moderators on the flux of back scattered neutrons were investigated. We have also experimentally verified the effect of BF3 detector shield and obtained good agreement with theory.     

Prediction of the backwater level due to bridge constriction in waterways

This article proposes a mathematical method to calculate the backwater level at bridge constrictions for compound channels. Such a model is necessary, as many of the previously developed simple formulas yield inaccurate results. Parametric studies on a single‐opening semicircular arch, single‐opening semielliptical arch and single‐opening straight deck bridge were also conducted using the commercial software HEC‐RAS to investigate the influences of different factors on backwater level. The results indicated that the Froude number, opening ratio, discharge and roughness coefficient impact the backwater level considerably. Hence, a simple mathematical method was developed based on these parameters and validated using experimental data in a symmetrical two‐stage channel with different roughness coefficients for different types of bridge models. The results obtained using the proposed formula corresponded well with the experimental data and the results obtained using the energy method, which is accurate and the most commonly used method to calculate backwater level.     

FE calculation of transient eddy currents in thin conductive sheets using dynamic boundary conditions

This paper presents an FE modelling approach for the calculation of transient eddy currents in thin conductive layers, where the complexity of the geometry prohibits both a detailed FE modelling and the use of analytical tools. The method allows an estimation of the maximum values of eddy currents at a highly reduced modelling effort and the use of a commercial FE software package. A prerequisite is a slowly varying magnetic field that can be assumed to be unaffected by the eddy currents. It is shown that neither the source of the magnetic field nor the insulating environment has to be modelled. The model is built up exclusively from 2D elements and is excited via the magnetic vector potential. The spatial distribution of the latter is calculated separately in a magnetostatic calculation based on Biot–Savart's law. It is then applied in time-varying form as a dynamic boundary condition at every node of the model. The method was applied to a simple problem for which the results of a detailed FE calculation were available, to document its validity. Further numerical results are presented for the plasma vessel and the heat radiation shield of the Wendelstein 7-X fusion experiment in the case of an emergency discharge. © 1998 John Wiley & Sons, Ltd.     

Stability and discriminant validity of the Adult Attachment Interview: A psychometric study in young Israeli adults.

59 male and female Israeli students were interviewed twice by 2 different interviewers at 3 mo intervals to assess the Adult Attachment Interview's (AAI; C. George et al, 1985) test–retest reliability and the effects of the interviewers on the interview itself as well as its subsequent classification. Various memory measures were used to obtain a wide range of information about Ss' memory abilities. Information was also obtained from the students' records about various intelligence-related skills. Results showed high degree of interjudge and test–retest reliabilities, irrespective of interviewers. The classifications on the AAI were not found to be associated with nonattachment-related memory and intelligence abilities. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Evaluation of fly ash- and slag-based geopolymers for the improvement of a soft marine clay by deep soil mixing

The use of deep soil mixing (DSM) in ground-improvement projects, for structures subjected to low to medium loads, has increased over the past decade due to its convenient and practical implementation and its economic advantages. Traditionally, Portland cement and lime have been the most popular binders for DSM applications. However, the ground-improvement industry has been keen to explore environmentally friendly alternatives with low carbon dioxide emission. The aim of this research is to investigate the use of two stockpiled industrial waste by-products, namely, fly ash (FA) and slag (S), as alternative green binders in ground-improvement projects that would reduce the carbon footprint of these projects. In this research, combinations of FA and S, activated by a liquid alkaline activator (L), were evaluated for the ground improvement of a soft marine clay, namely, Coode Island Silt (CIS). The performance of the FA?+?S geopolymers was compared with that of traditional cement and lime control binders. The soil moisture content was set at 0.75, 1.0 and 1.25 of the liquid limit (LL) of the soil to replicate the field conditions. 10, 20 and 30% binders, by dry soil mass, were added to the soil, and the samples were cured for 7 and 28?days. Unconfined compression strength (UCS), flexural beam and scanning electron microscopy (SEM) imaging tests were conducted to evaluate the changes in the engineering behavior and the microstructure of the mixtures. The results indicated that the strength and stiffness of the soft clay were significantly increased by the use of these new FA?+?S binders, which substantiated them as alternatives to traditional cement or lime binders. The optimum binder content was found to be 20%, while CIS?+?5%FA?+?15%S was found to be the optimum mixture. Furthermore, correlations between the UCS and the modulus of elasticity (E₅₀) and between the UCS and the modulus of rupture (R) for the geopolymer mixtures were proposed. They will be valuable to both designers and practitioners of ground-improvement works.     

Carbon nanotube field effect transistors with suspended graphene gates

Novel field effect transistors with suspended graphene gates are demonstrated. By incorporating mechanical motion of the gate electrode, it is possible to improve the switching characteristics compared to a static gate, as shown by a combination of experimental measurements and numerical simulations. The mechanical motion of the graphene gate is confirmed by using atomic force microscopy to directly measure the electrostatic deflection. The device geometry investigated here can also provide a sensitive measurement technique for detecting high-frequency motion of suspended membranes as required, e.g., for mass sensing.     

The effects of selenium deficiency, dietary selenium, and vitamin E supplementation on the oxidative status of pig liver

The aim of this work was to determine the effect of selenium (Se) deficiency on the porcine liver oxidative stability and to investigate Se content and oxidative status in porcine liver after dietary supplementation with vitamin E (vit E), sodium selenite, and selenized yeast. Experimental animals were fed a basal corn meal, low in Se and vit E, for a 4-week depletion period before being given the experimental diets containing different levels of Se and/or vit E for 5 months. Dietary treatments were the basal diet with no additions (control); the basal diet supplemented with 25 mg of vit E/kg of feed (group I); basal diet + 0.3 mg selenite-Se/kg (group II); basal diet + 0.3 mg selenized yeast-Se/kg (group III); basal diet + 0.1 mg selenite-Se + 10 mg vit E/kg (group IV); and basal diet + 0.3 mg selenite-Se + 25 mg vit E/kg (group V). The Se content in pig liver samples was 33 to 192% lower in the control group than in all the other groups. Dietary Se from selenized yeast had a more pronounced effect on Se level than dietary sodium selenite. The highest Se content was found in liver samples from the Se + vit E supplemented group (group V). All the dietary supplementation schemes significantly improved the oxidative status of porcine liver compared with the control group samples. The best results were obtained by simultaneous dietary supplementation with Se + vit E (groups IV and V) > group III > group II > group I.