Fundamental Finite Key Limits for One-Way Information Reconciliation in Quantum Key Distribution

The security of quantum key distribution protocols is guaranteed by the laws of quantum mechanics. However, a precise analysis of the security properties requires tools from both classical cryptography and information theory. Here, we employ recent results in non-asymptotic classical information theory to show that one-way information reconciliation imposes fundamental limitations on the amount of secret key that can be extracted in the finite key regime. In particular, we find that an often used approximation for the information leakage during information reconciliation is not generally valid. We propose an improved approximation that takes into account finite key effects and numerically test it against codes for two probability distributions, that we call binary-binary and binary-Gaussian, that typically appear in quantum key distribution protocols

Green-emitting Zn(II) halide complexes with N,N,N',N'-tetramethyl-P-indol-1-ylphosphonic diamide as ligand

Zn(II) derivatives are of current interest for photophysical applications because they can enhance the emission of fluorescent ligands upon coordination. In addition, LMCT transitions involving the low-lying s or p empty orbitals of the metal center have been reported [1,2]. Herein we report the synthesis and characterization of tetrahedral Zn(II) complexes having general formula [ZnX2L2] (X = Cl, Br, I; L = N,N,N',N'-tetramethyl-P-indol-1-ylphosphonic diamide). The species were isolated from the reaction between the proper anhydrous ZnX2 salt and L under mild conditions. The structure of all the three derivatives was ascertained by single-crystal X-ray diffraction. The three species revealed to be appreciably luminescent in the green region upon excitation with UV-light below 300 nm, with emission bands centered between 520 and 530 nm. The high Stokes shifts and the luminescence lifetimes in the μs range suggest that triplet excited states are involved in the emission. On the other hand, the absorption bands are essentially ascribable to the π*←π transition of the indolyl fragment, as confirmed by DFT calculations

CIO Executive Risk Behavior Model

As evidenced in a broad-based body of research, risk affects decision-maker’s behavior by influencing perceptions of decision situations, evaluation of alternatives, choices made, and other decision-related actions taken in response to risk. Based on theory from risk literature, a conceptual model was identified and tested. The data for this study was collected using a stratified random sample from the top Chief Information Officer (CIO) of the banking industry. The survey instrument collected information pertaining to the CIO executive’s risk behavior preference. The analysis of the data was used to determine an effective risk behavior model that can be used for future business decision making process. It is the anticipation that this model can be used to determine the CIOs risk behavior in decision making that would impact the information systems (IS) strategy. The CIOs risk behavior model tested indicated evidence supporting the proposition that both risk propensity and risk perception influenced the ultimate risk behavior of the CIO executive that influences the decision making process. These findings signify that the proposed CIOs risk behavior model is robust

Sistema de informação para a gestão de uma frota

Actualmente, vivemos num mundo complexo em que as organizações são entidades nas quais a Informação e os Sistemas de Informação são imprescindíveis para garantir a sua sobrevivência e para responder às suas necessidades. O desenvolvimento de um Sistema de Informação para a gestão de uma organização tem como papel principal o de apoiar a tomada de decisão, de forma a aumentar o sucesso e a competitividade da organização. Este artigo apresenta a tecnologia associada a um sistema de apoio à decisão que permite efectuar a gestão de uma frota, dentro de uma organização. Para efectuar a gestão de uma frota é necessário analisar e controlar os custos de utilização, manutenção e reparação de viaturas

Sequential curing of thiol-acetoacetate-acrylate thermosets by latent Michael addition reactions

Thiol-acetoacetate-acrylate ternary dual-curing thermosets were prepared by a sequential process consisting of thiol-Michael addition to acrylates at room temperature followed by Michael addition of acetoacetates to acrylates at moderately elevated temperature. The curing sequence can be controlled with the help of the different acidities of the protons on thiol and acetoacetate groups, the favorable pKa of the base used as catalyst and the self-limiting character of Michael additions. The latency of the curing steps can be regulated by selection of the right catalysts, temperature and curing conditions. The properties of the intermediate and final materials can be tuned by changing the structure of the monomers and the contribution of both Michael addition reactions.Postprint (author's final draft

Visible-emitting Cu(i) complexes with N-functionalized benzotriazole-based ligands

Luminescent mono- and dinuclear cationic heteroleptic Cu(I) complexes [Cu(N∧N′)(P)2]+, [Cu(N∧N′)(P∧P)]+ or [Cu2(N∧N′)2(μ-P∧P)2]2+ containing bidentate N-donor ligands (N∧N′) with benzotriazole, pyridine, pyrimidine or substituted triazine moieties in combination with mono- (P) and bidentate (P∧P) phosphines were synthesized and characterized. Eight single-crystal X-ray diffraction structures were obtained and showed marked distortions from the ideal tetrahedral geometry around Cu(I). Cyclic voltammetry on selected complexes showed reduction processes around −2 V vs. ferrocene/ferrocenium and irreversible oxidation close to 1 V. The long-wavelength absorptions were observed in the range of 350 to 450 nm and attributed to MLCT transitions. Upon excitation with near-UV and violet light, the complexes exhibited emissions from bright yellow (max 538 nm) to red (max 637 nm). Emission maxima, luminescence lifetimes and photoluminescence quantum yields that reach up to 0.92 on powder samples resulted in strong dependence on the choice of the coordinated ligands, the acceptor character of the N∧N′ ligands in particular. DFT calculations confirmed the electrochemical and photophysical outcomes and strongly suggested that the emission has a metal-to-ligand charge transfer (MLCT) nature, with intersystem crossing affording triplet emitting states

A sustainable bottom-up approach for Non-Governmental development organizations

Martin, R. S., Painho, M., & Cruz-Jesus, F. (2019). Addressing geospatial preparedness inequity: A sustainable bottom-up approach for Non-Governmental development organizations. Sustainability (Switzerland), 11(23), [6634]. https://doi.org/10.3390/su11236634In less developed areas, the use of Geographic Information Systems (GIS) to coordinate disaster response is hindered by a lack of geospatial preparedness. Humanitarian missions often rely on OpenStreetMap as a source of information to overcome this limitation. In these places, Non-Governmental Organizations (NGOs) might already be using GIS to implement development projects before the disaster. This study considers the management of geospatial information by those NGOs and whether they could improve geospatial preparedness from within the communities. This bottom-up approach would allow the inclusion of information relevant to the community in the disaster response decision-making process. The research method was an online survey with a worldwide sample of more than 200 development NGOs. The results show that many NGOs use digital geographic information, mostly open-data. They could indeed improve geospatial preparedness while using open-data and community mapping for the implementation of their projects. There is, however, a limitation; most of the development NGOs using open geographic data are not familiar with the open platforms used by the humanitarian community (i.e., OpenStreetMap). Therefore, the study indicates that the sustainability of this synergic approach requires further harmonization between development and humanitarian organizations working for the wellbeing of the same communities.publishersversionpublishe

Anisotropic dispersive Henry problem

The Henry problem has played a key role in our understanding of seawater intrusion into coastal aquifers and in benchmarking density dependent flow codes. This paper seeks to modify Henry’s problem to ensure sensitivity to density variations and vertical salinity profiles that resemble field observations. In the proposed problem, the “dispersive Henry problem”, mixing is represented by means of the traditional Scheidegger dispersion tensor (dispersivity times water flux). Anisotropy in the hydraulic conductivity is acknowledged and Henry’s seaside boundary condition of prescribed salt concentration is replaced by a flux dependent boundary condition, which represents more realistically salt transport across the seaside boundary. This problem turns out to be very sensitive to density variations and its solution gets closer to reality. However, an improvement in the traditional Henry problem (gain in sensitivity and realism) can be also achieved if the value of the Peclet number is significantly reduced. Although the dispersive problem lacks an analytical solution, it can shed light on flow in coastal aquifers. It provides significant information about the factors controlling seawater penetration, width of the mixing zone and influx of seawater. The width of the mixing zone depends basically on dispersion with longitudinal and transverse dispersion controlling different parts of the mixing zone but displaying similar overall effects. Toe penetration is mainly controlled by the horizontal permeability and by the geometric mean of the dispersivities. Finally, transverse dispersivity and the geometric mean of the hydraulic conductivity are the leading parameters controlling the amount of saltwater that enters the aquife