8,051 research outputs found
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
The influence of planning and response inhibition on cognitive functioning of Non-Psychotic unipolar depressed suicide attempters
Depression is one of the main risk factors for suicide. However, little is known about the intricate relationships among depressive symptomatology in unipolar depression, suicide risk, and the characteristics of executive dysfunction in depressed patients. We compared 20 non-psychotic unipolar depressed suicide attempters to 20 matching depressed non-attempters and to 20 healthy controls to further investigate the possible differences in neuropsychological performance. Depressed subjects were controlled for current suicidal ideation, and their neuropsychological profile was assessed using a range of measures of executive functioning, attention, verbal memory, processing speed, and psychomotor speed. Depressed groups were outperformed by healthy controls. Depressed attempters presented more cognitive impairment than depressed non-attempters on a simple Go/No-go response inhibition task and performed better than non-attempters on the Tower of London planning task. Depressed attempters were clearly distinguished by a deficit in response inhibition (Go/No-go commission errors). The normative planning performance (Tower of London extra moves) of the suicide attempters was unexpected, and this unanticipated finding calls for further research. Normative planning may indicate an increased risk of suicidal behavior.info:eu-repo/semantics/publishedVersio
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
- …