Bacon-Shor code with continuous measurement of non-commuting operators

We analyze the operation of a four-qubit Bacon-Shor code with simultaneous continuous measurement of non-commuting gauge operators. The error syndrome in this case is monitored via time-averaged cross-correlators of the output signals. We find the logical error rate for several models of decoherence, and also find the termination rate for this quantum error detecting code. The code operation is comparable to that based on projective measurements when the collapse timescale due to continuous measurements is an order of magnitude less than the time period between the projective measurements. An advantage of the continuous-measurement implementation is the absence of time-dependence in the code operation, with passive continuous monitoring of the error syndrome.Comment: 25 pages, 8 figure

Social Transmission of Experience of Agency: An Experimental Study

The sense of controlling one’s own actions is fundamental to normal human mental function, and also underlies concepts of social responsibility for action. However, it remains unclear how the wider social context of human action influences sense of agency. Using a simple experimental design, we investigated, for the first time, how observing the action of another person or a robot could potentially influence one’s own sense of agency. We assessed how observing another’s action might change the perceived temporal relationship between one’s own voluntary actions and their outcomes, which has been proposed as an implicit measure of sense of agency. Working in pairs, participants chose between two action alternatives, one rewarded more frequently than the other, while watching a rotating clock hand. They judged, in separate blocks, either the time of their own action, or the time of a tone that followed the action. These were compared to baseline judgements of actions alone, or tones alone, to calculate the perceptual shift of action toward outcome and vice versa. Our design focused on how these two dependent variables, which jointly provide an implicit measure of sense of agency, might be influenced by observing another’s action. In the observational group, each participant could see the other’s actions. Multivariate analysis showed that the perceived time of action and tone shifted progressively toward the actual time of outcome with repeated experience of this social situation. No such progressive change occurred in other groups for whom a barrier hid participants’ actions from each other. However, a similar effect was observed in the group that viewed movements of a human-like robotic hand, rather than actions of another person. This finding suggests that observing the actions of others increases the salience of the external outcomes of action and this effect is not unique to observing human agents. Social contexts in which we see others controlling external events may play an important role in mentally representing the impact of our own actions on the external world

Unusual Behaviour of an Earth-Rockhill Dam

The post-construction behaviour of a 47.5 m high and 700 m long earth-rockfill dam, located in northwestern Iran, is described. The embankment dam is founded on Tertiary rock on both abutments, but in the river channel it rests on alluvial deposits of variable composition and thickness. Since the first impoundment, the dam has undergone large deformations, both in vertical and in horizontal directions. These have resulted in unusual differential settlements, visible along the crest, and have produced wide longitudinal cracks in the asphalt pavement of the crest road. The principle features of the dam are described and selected monitoring results of the crest movements for a sixteen year period are presented. Based on the analysis of the available data and taking into account the geotechnical characteristics of the foundation and the fill materials, an interpretation of the unusual behaviour has been attempted

Folate-conjugated nanoparticles as a potent therapeutic approach in targeted cancer therapy

The selective and efficient drug delivery to tumor cells can remarkably improve different cancer therapeutic approaches. There are several nanoparticles (NPs) which can act as a potent drug carrier for cancer therapy. However, the specific drug delivery to cancer cells is an important issue which should be considered before designing new NPs for in vivo application. It has been shown that cancer cells over-express folate receptor (FR) in order to improve their growth. As normal cells express a significantly lower levels of FR compared to tumor cells, it seems that folate molecules can be used as potent targeting moieties in different nanocarrier-based therapeutic approaches. Moreover, there is evidence which implies folate-conjugated NPs can selectively deliver anti-tumor drugs into cancer cells both in vitro and in vivo. In this review, we will discuss about the efficiency of different folate-conjugated NPs in cancer therapy. © 2015, International Society of Oncology and BioMarkers (ISOBM)

A hierarchical key pre-distribution scheme for fog networks

Security in fog computing is multi-faceted, and one particular challenge is establishing a secure communication channel between fog nodes and end devices. This emphasizes the importance of designing efficient and secret key distribution scheme to facilitate fog nodes and end devices to establish secure communication channels. Existing secure key distribution schemes designed for hierarchical networks may be deployable in fog computing, but they incur high computational and communication overheads and thus consume significant memory. In this paper, we propose a novel hierarchical key pre-distribution scheme based on “Residual Design” for fog networks. The proposed key distribution scheme is designed to minimize storage overhead and memory consumption, while increasing network scalability. The scheme is also designed to be secure against node capture attacks. We demonstrate that in an equal-size network, our scheme achieves around 84% improvement in terms of node storage overhead, and around 96% improvement in terms of network scalability. Our research paves the way for building an efficient key management framework for secure communication within the hierarchical network of fog nodes and end devices. KEYWORDS: Fog Computing, Key distribution, Hierarchical Networks

Exchange, correlation, and scattering effects on surface plasmons in arm-chair graphene nanoribbons

Using Maxwell’s equations for the incoming and outgoing electromagnetic field, in interaction with a metallic arm-chair graphene nanoribbon (AGNR), and the relationship between the density-density response function and the conductivity, we study surface plasmons (SPs) in a AGNR following the Lindhard, random-phase approximation (RPA), and Hubbard approaches. For transverse magnetic (TM) modes we obtain analytical dispersion relations (DRs) valid for q ≤ kF and assess their width dependence. In all approaches we include screening. In the long-wavelength limit q → 0 there is a small but noticeable difference between the DRs of the three approaches. In this limit the respective, scattering-free conductivities differ drastically from those obtained when scattering by impurities is included. We demonstrate that the SP field is proportional to the square of the quality factor Q. The reflection amplitude shows that metallic AGNRs do not support Brewster angles. In addition, AGNRs do not support transverse electric (TE) SPs