A genuine maximally seven-qubit entangled state

Contrary to A.Borras et al.'s [1] conjecture, a genuine maximally seven-qubit entangled state is presented. We find a seven-qubit state whose marginal density matrices for subsystems of 1,2- qubits are all completely mixed and for subsystems of 3-qubits is almost completely mixed

The effect of tax structure in economic growth

The main goal of this paper is to analyse the effect of the tax structure in the economic growth of Kosovo in the period 2007-2015. The study intends to evaluate the impact of specific types of taxes on economic growth. The methodology is based on comparative analysis of data using primary and secondary sources. Through the econometric model and linear regression analysis, the research hypotheses have been tested with STATA application/software to calculate the impact of tax structure in economic growth. The econometric model includes several independent variables (types of taxes), and the dependent variable GDP. Based on data obtained through the log-log model, the results show the impact of special taxes such as Pt, It, VAT, Wt, Ibt, Tdr.., Ct on GDP. The results show that most of the taxes have a positive impact on GDP growth; it is also shown that not all taxes have the same impact on economic growth. In the econometric analysis the coefficient of R2=0,999 reflects the high degree of determination with 99.9% forecasting accuracy.peer-reviewe

An Optimized Round-Robin Scheduling of Speakers for Peers-to-Peers-Based Byzantine Faulty Tolerance

© 2018 IEEE. Blockchain technology has been showing its strong performance on decentralized security when integrating with Internet of Things network. However, the trilemma of scalability-security-decentralization exists in Blockchain-based IoT. Therein the typical round-robin scheduling implemented in the Byzantine Faulty Tolerance (BFT) proposed by Neo's Blockchain has a significant delay when consecutive faulty miners exist. This paper proposes a novel analysis model for evaluating the network performance collapse in general, followed by an optimized round-robin scheduling for the case when the mutual latency difference is not significant enough for ranking. Based on the model, the optimized mechanism is able to increase the block rate for a specific subset of consecutive faulty miners by nearly 50% and provide a linearly positive growth rate of the mitigation with respect to the fail rate of a single miner, which strongly promotes the efficiency of the P2P-based BFT consensus algorithm

Magnetic Coherence in Cuprate Superconductors

Recent inelastic neutron scattering (INS) experiments on La$_{2-x}$Sr$_x$CuO$_4$ observed a {\it magnetic coherence effect}, i.e., strong frequency and momentum dependent changes of the spin susceptibility, $\chi''$, in the superconducting phase. We show that this effect is a direct consequence of changes in the damping of incommensurate antiferromagnetic spin fluctuations due to the appearance of a d-wave gap in the fermionic spectrum. Our theoretical results provide a quantitative explanation for the weak momentum dependence of the observed spin-gap. Moreover, we predict {\bf (a)} a Fermi surface in La$_{2-x}$Sr$_x$CuO$_4$ which is closed around $(\pi,\pi)$ up to optimal doping, and {\bf (b)} similar changes in $\chi''$ for all cuprates with an incommensurate magnetic response.Comment: 5 pages, 4 figures, Fig.3 is in colo

Attack and Defence of Ethereum Remote APIs

© 2018 IEEE. Ethereum, as the first Turing-complete blockchain platform, provides various application program interfaces for developers. Although blockchain has highly improved security, faulty configuration and usage can result in serious vulnerabilities. In this paper, we focus on the security vulnerabilities of the official Go-version Ethereum client (geth). The vulnerabilities are because of the insecure API design and the specific Ethereum wallet mechanism. We demonstrate attacks exploiting these vulnerabilities in an Ethereum testbed. The vulnerabilities are confirmed by the scanning results on the public Internet. Finally, corresponding countermeasures against attacks are provided to enhance the security of the Ethereum platform

Pulmonary Imaging Biomarkers of Gas Trapping and Emphysema in COPD: (3)He MR Imaging and CT Parametric Response Maps

PURPOSE: To directly compare magnetic resonance (MR) imaging and computed tomography (CT) parametric response map (PRM) measurements of gas trapping and emphysema in ex-smokers both with and without chronic obstructive pulmonary disease (COPD). MATERIALS AND METHODS: Participants provided written informed consent to a protocol that was approved by a local research ethics board and Health Canada and was compliant with the HIPAA (Institutional Review Board Reg. #00000940). The prospectively planned study was performed from March 2014 to December 2014 and included 58 ex-smokers (mean age, 73 years ± 9) with (n = 32; mean age, 74 years ± 7) and without (n = 26; mean age, 70 years ± 11) COPD. MR imaging (at functional residual capacity plus 1 L), CT (at full inspiration and expiration), and spirometry or plethysmography were performed during a 2-hour visit to generate ventilation defect percent (VDP), apparent diffusion coefficient (ADC), and PRM gas trapping and emphysema measurements. The relationships between pulmonary function and imaging measurements were determined with analysis of variance (ANOVA), Holm-Bonferroni corrected Pearson correlations, multivariate regression modeling, and the spatial overlap coefficient (SOC). RESULTS: VDP, ADC, and PRM gas trapping and emphysema (ANOVA, P \u3c .001) measurements were significantly different in healthy ex-smokers than they were in ex-smokers with COPD. In all ex-smokers, VDP was correlated with PRM gas trapping (r = 0.58, P \u3c .001) and with PRM emphysema (r = 0.68, P \u3c .001). VDP was also significantly correlated with PRM in ex-smokers with COPD (gas trapping: r = 0.47 and P = .03; emphysema: r = 0.62 and P \u3c .001) but not in healthy ex-smokers. In a multivariate model that predicted PRM gas trapping, the forced expiratory volume in 1 second normalized to the forced vital capacity (standardized coefficients [βS] = -0.69, P = .001) and airway wall area percent (βS = -0.22, P = .02) were significant predictors. PRM emphysema was predicted by the diffusing capacity for carbon monoxide (βS = -0.29, P = .03) and VDP (βS = 0.41, P = .001). Helium 3 ADC values were significantly elevated in PRM gas-trapping regions (P \u3c .001). The spatial relationship for ventilation defects was significantly greater with PRM gas trapping than with PRM emphysema in patients with mild (for gas trapping, SOC = 36% ± 28; for emphysema, SOC = 1% ± 2; P = .001) and moderate (for gas trapping, SOC = 34% ± 28; for emphysema, SOC = 7% ± 15; P = .006) COPD. For severe COPD, the spatial relationship for ventilation defects with PRM emphysema (SOC = 64% ± 30) was significantly greater than that for PRM gas trapping (SOC = 36% ± 18; P = .01). CONCLUSION: In all ex-smokers, ADC values were significantly elevated in regions of PRM gas trapping, and VDP was quantitatively and spatially related to both PRM gas trapping and PRM emphysema. In patients with mild to moderate COPD, VDP was related to PRM gas trapping, whereas in patients with severe COPD, VDP correlated with both PRM gas trapping and PRM emphysema

Model of C-Axis Resistivity of High-\Tc Cuprates

We propose a simple model which accounts for the major features and systematics of experiments on the $c$-axis resistivity, $\rho_c$, for \lsco, \ybco and \bsco . We argue that the $c$-axis resistivity can be separated into contributions from in-plane dephasing and the $c$-axis ``barrier'' scattering processes, with the low temperature semiconductor-like behavior of $\rho_c$ arising from the suppression of the in-plane density of states measured by in-plane magnetic Knight shift experiments. We report on predictions for $\rho_c$ in impurity-doped \ybco materials.Comment: 10 pages + figures, also see March Meeting J13.1

Space efficient opposed-anvil high-pressure cell and its application to optical and NMR measurements up to 9 GPa

We have developed a new type of opposed-anvil high pressure cell with substantially improved space efficiency. The clamp cell and the gasket are made of non-magnetic Ni-Cr-Al alloy. Non-magnetic tungsten carbide (NMWC) is used for the anvils. The assembled cell with the dimension \phi 29mm \times 41mm is capable of generating pressure up to 9 GPa over a relatively large volume of 7 mm3. Our cell is particularly suitable for those experiments which require large sample space to achieve good signal-to-noise ratio, such as the nuclear magnetic resonance (NMR) experiment. Argon is used as the pressure transmitting medium to obtain good hydrostaticity. The pressure was calibrated in situ by measuring the fluorescence from ruby through a transparent moissanite (6H-SiC) window. We have measured the pressure and temperature dependences of the 63Cu nuclear-quadrupole-resonance (NQR) frequency of Cu2O, the in-plane Knight shift of metallic tin, and the Knight shift of platinum. These quantities can be used as reliable manometers to determine the pressure values in situ during the NMR/NQR experiments up to 9 GPa.Comment: 9 pages, 5 figures, 3 tables, accepted for publication in J. Phys. Soc. Jp