The fragmentation instability of a black hole with f(R)f(R) global monopole under GUP

The fragmentation of black hole containing $f(R)$ global monopole under GUP is studied. We focus on that the black hole breaks into two parts. We derive the entropies of the initial black hole and the broken parts while the generalization of Heisenberg's uncertainty principle is introduced. We find that the $f(R)$ global monopole black hole keeps stable instead of breaking because the entropy difference is negative without the generalization. The fragmentation of the black hole will happen if the black hole entropies are limited by the GUP and the considerable deviation from the general relativity leads the case that the mass of one fragmented black hole is extremely small and the other one is extremely large.Comment: 9 pages, 4 figure

CardioCam: Leveraging Camera on Mobile Devices to Verify Users While Their Heart is Pumping

With the increasing prevalence of mobile and IoT devices (e.g., smartphones, tablets, smart-home appliances), massive private and sensitive information are stored on these devices. To prevent unauthorized access on these devices, existing user verification solutions either rely on the complexity of user-defined secrets (e.g., password) or resort to specialized biometric sensors (e.g., fingerprint reader), but the users may still suffer from various attacks, such as password theft, shoulder surfing, smudge, and forged biometrics attacks. In this paper, we propose, CardioCam, a low-cost, general, hard-to-forge user verification system leveraging the unique cardiac biometrics extracted from the readily available built-in cameras in mobile and IoT devices. We demonstrate that the unique cardiac features can be extracted from the cardiac motion patterns in fingertips, by pressing on the built-in camera. To mitigate the impacts of various ambient lighting conditions and human movements under practical scenarios, CardioCam develops a gradient-based technique to optimize the camera configuration, and dynamically selects the most sensitive pixels in a camera frame to extract reliable cardiac motion patterns. Furthermore, the morphological characteristic analysis is deployed to derive user-specific cardiac features, and a feature transformation scheme grounded on Principle Component Analysis (PCA) is developed to enhance the robustness of cardiac biometrics for effective user verification. With the prototyped system, extensive experiments involving 25 subjects are conducted to demonstrate that CardioCam can achieve effective and reliable user verification with over 99% average true positive rate (TPR) while maintaining the false positive rate (FPR) as low as 4%

Effect of Repeated Thermal Shock on Mechanical Properties of ZrB 2

ZrB2-20 vol.% SiC-10 vol.% h-BN (particles) ceramic composites (ZSB) were fabricated by hot pressing under inert gas protected. ZSB samples with mean size 75 × 55 × 40 mm3 were heated using current heating method and then cooled down to low temperature by circulating water. ZSB samples repeatedly went through thermal shock with 10–50 times under various conditions, respectively. Diverse effects on residual strength of ZSB at different experiment conditions (temperatures, thermal shock times, and heating rates) were investigated. The test results indicated that the residual strength of specimen materials all reached the maximum while the temperature was 1600°C and thermal shock number was less than 50 times. Because ZSB samples could not stand the extremely serious hyperoxidation at very high temperature (1800°C), the residual strength of samples decreased sharply. At 1600°C, when the thermal shock times was 20, ZSB samples’ residual strength reached the maximum, but it decreased to the lowest point while the thermal shock times was 30. So we argued that the sensitive thermal shock number was 30. Finally, we analyzed the influences on samples residual strength generated by different heating rates at the same temperature and thermal shock number; the results showed that when heating rate was equal to cooling rate, the residual strength of specimen materials reached the maximum

Plane Constraints Aided Multi-Vehicle Cooperative Positioning Using Factor Graph Optimization

The development of vehicle-to-vehicle (V2V) communication facil-itates the study of cooperative positioning (CP) techniques for vehicular applications. The CP methods can improve the posi-tioning availability and accuracy by inter-vehicle ranging and data exchange between vehicles. However, the inter-vehicle rang-ing can be easily interrupted due to many factors such as obsta-cles in-between two cars. Without inter-vehicle ranging, the other cooperative data such as vehicle positions will be wasted, leading to performance degradation of range-based CP methods. To fully utilize the cooperative data and mitigate the impact of inter-vehicle ranging loss, a novel cooperative positioning method aided by plane constraints is proposed in this paper. The positioning results received from cooperative vehicles are used to construct the road plane for each vehicle. The plane parameters are then introduced into CP scheme to impose constraints on positioning solutions. The state-of-art factor graph optimization (FGO) algo-rithm is employed to integrate the plane constraints with raw data of Global Navigation Satellite Systems (GNSS) as well as inter-vehicle ranging measurements. The proposed CP method has the ability to resist the interruptions of inter-vehicle ranging since the plane constraints are computed by just using position-related data. A vehicle can still benefit from the position data of cooperative vehicles even if the inter-vehicle ranging is unavaila-ble. The experimental results indicate the superiority of the pro-posed CP method in positioning performance over the existing methods, especially when the inter-ranging interruptions occur.Comment: 14 pages, 16 figures, IEEE trans on IT

Import technology sophistication and high-quality economic development: evidence from city-level data of China

This paper adopts five dimensions and 15 indexes of green development, people’s life, innovation ability, economic vitality and coordinated development to establish an evaluation system of high-quality economic development. It uses principal component analysis to measure the economic high-quality development of 233 prefecture-level cities from 2003 to 2016, and empirically studies the impact of import sophistication on China’s high-quality economic development. The results show that the increase in the sophistication of imported technology can significantly promote the high-quality development of the regional economy, and this effect is applicable to both imported intermediate and final products. In regions with higher and lower levels of economic development, eastern areas, and regions with high-quality development above 90% quantiles, the increase in imported technology content can significantly drive the high-quality development of the local economy. However, it has a great negative impact on the areas with a high-quality development index below 10% quantile. The robustness and endogeneity check support the above viewpoint. Further mechanism analysis shows that the final product import competition and intermediate product import spillover play a mediating role in the process of import sophistication affecting the high-quality economic development. The conclusion of this paper has important theoretical value and practical significance for the use of import trade to achieve high-quality economic development

2-Cyano-N′-(2-hy­droxy-3-meth­oxy­benzyl­idene)acetohydrazide

The title compound, C11H11N3O3, was obtained by the reaction of 3-meth­oxy­salicyl­aldehyde with cyano­acetohydrazide in methanol. There is an intra­molecular O—H⋯N hydrogen bond in the mol­ecule. In the crystal, mol­ecules are linked by N—H⋯O hydrogen bonds, generating chains running along the b axis

Multi-Field Synergy Process for Polymer Plasticization: A Novel Design Concept for Screw to Facilitate Phase-to-Phase Thermal and Molecular Mobility

A novel concept of screw design has been proposed considering the multi-field synergy principle to facilitate phase-to-phase thermal and molecular mobility; subsequently, a torsion element has been designed. This new screw design allows an innovative and effective way to resolve a growing challenge in polymer process engineering, especially for nanocomposites or biopolymers, that is, an inadequate control of mass transfer and thermal management for multicomponent melt flows through narrow channels during extrusion or injection. The adaption of torsion element in the screw facilitated the plasticization mixing and thermal distribution in polymer melts, and the torsional flow induced by the torsion elements shows a synergistic effect on the melt-phase mass flow and the thermal flow field. The latter effect enhances the mass and heat transfer of heterogeneous polymer systems and realizes effective heat management to achieve properly uniform temperature field