Satellite Broadcasting Enabled Blockchain Protocol: A Preliminary Study

Low throughput has been the biggest obstacle of large-scale blockchain applications. During the past few years, researchers have proposed various schemes to improve the systems' throughput. However, due to the inherent inefficiency and defects of the Internet, especially in data broadcasting tasks, these efforts all rendered unsatisfactory. In this paper, we propose a novel blockchain protocol which utilizes the satellite broadcasting network instead of the traditional Internet for data broadcasting and consensus tasks. An automatic resumption mechanism is also proposed to solve the unique communication problems of satellite broadcasting. Simulation results show that the proposed algorithm has a lower communication cost and can greatly improve the throughput of the blockchain system. Theoretical estimation of a satellite broadcasting enabled blockchain system's throughput is 6,000,000 TPS with a 20 gbps satellite bandwidth.Comment: Accepted by 2020 Information Communication Technologies Conference (ICTC 2020

Warped Brane worlds in Critical Gravity

We investigate the brane models in arbitrary dimensional critical gravity presented in [Phys. Rev. Lett. 106, 181302 (2011)]. For the model of the thin branes with codimension one, the Gibbons-Hawking surface term and the junction conditions are derived, with which the analytical solutions for the flat, AdS, and dS branes are obtained at the critical point of the critical gravity. It is found that all these branes are embedded in an AdS$_{n}$ spacetime, but, in general, the effective cosmological constant $\Lambda$ of the AdS$_{n}$ spacetime is not equal to the naked one $\Lambda_0$ in the critical gravity, which can be positive, zero, and negative. Another interesting result is that the brane tension can also be positive, zero, or negative, depending on the symmetry of the thin brane and the values of the parameters of the theory, which is very different from the case in general relativity. It is shown that the mass hierarchy problem can be solved in the braneworld model in the higher-derivative critical gravity. We also study the thick brane model and find analytical and numerical solutions of the flat, AdS, and dS branes. It is find that some branes will have inner structure when some parameters of the theory are larger than their critical values, which may result in resonant KK modes for some bulk matter fields. The flat branes with positive energy density and AdS branes with negative energy density are embedded in an $n$-dimensional AdS spacetime, while the dS branes with positive energy density are embedded in an $n$-dimensional Minkowski one.Comment: 14 pages, 7 figures, updated version, accepted by EPJ

Modelling Work Effort of Workers in the Crowdsourcing Intermediary Market

This study examines crowdsourcing task characteristics (skill variety, task identity, task significance, autonomy, feedback, and task clarity) and the online work situation factor; that is, the trust in evaluations on work effort in the crowdsourcing intermediary market. An e-questionnaire was released as a crowdsourcing task on the Time Fortune website in China; data from 231 valid questionnaires were analyzed using SmartPLS 3 software. Results show that under the conditions of this study, crowdsourcing workers’ internal motivation has a significant positive relationship with their effort. Task autonomy and feedback have significant and positive relationship with internal motivation. Skill variety, task significance, task clarity, and task identity have no significant correlation with internal motivation. However, task clarity has a significant and positive relationship with work effort. The study also finds that the effect of workers’ trust in the task requester on work effort is mediated by internal motivation

General stationary charged black holes as charged particle accelerators

We study the possibility of getting infinite energy in the center of mass frame of colliding charged particles in a general stationary charged black hole. For black holes with two-fold degenerate horizon, it is found that arbitrary high center-of-mass energy can be attained, provided that one of the particle has critical angular momentum or critical charge, and the remained parameters of particles and black holes satisfy certain restriction. For black holes with multiple-fold degenerate event horizons, the restriction is released. For non-degenerate black holes, the ultra-high center-of-mass is possible to be reached by invoking the multiple scattering mechanism. We obtain a condition for the existence of innermost stable circular orbit with critical angular momentum or charge on any-fold degenerate horizons, which is essential to get ultra-high center-of-mass energy without fine-tuning problem. We also discuss the proper time spending by the particle to reach the horizon and the duality between frame dragging effect and electromagnetic interaction. Some of these general results are applied to braneworld small black holes.Comment: 23 pages, no figures, revised version accepted for publication in Phys. Rev.

Looking Forward to Seeing Real Experiences through Photos? It Depends on the Quality of Photos

We investigated whether the quality of photos will exert an influence on the post-evaluation of the experience? Through two experiments, we found that the effect does exist. When people reactivate memories through photos, photos can work in the following ways. First, photos can make the memory related to photo content more prominent. Secondly, photos content can replace the already obscured original memory to a certain extent. When the quality of photos is high, people tend to accept the memory being reprocessed, driven by photos, thus improving the evaluation of the original experience. When the quality of the photos is low, people subconsciously reject the information that photos convey and still insist on the judgment of the original experience. The above scenarios apply when people still have an initial impression on their experiences