3,054 research outputs found
On the Common Envelope Efficiency
In this work, we try to use the apparent luminosity versus displacement
(i.e., vs. ) correlation of high mass X-ray binaries (HMXBs) to
constrain the common envelope (CE) efficiency , which is a key
parameter affecting the evolution of the binary orbit during the CE phase. The
major updates that crucial for the CE evolution include a variable
parameter and a new CE criterion for Hertzsprung gap donor stars, both of which
are recently developed. We find that, within the framework of the standard
energy formula for CE and core definition at mass \%, a high value of
, i.e., around 0.8-1.0, is more preferable, while likely can not reconstruct the observed vs.
distribution. However due to an ambiguous definition for the core boundary in
the literature, the used here still carries almost two order of
magnitude uncertainty, which may translate directly to the expected value of
. We present the detailed components of current HMXBs and
their spatial offsets from star clusters, which may be further testified by
future observations of HMXB populations in nearby star-forming galaxies.Comment: 14 pages, 10 figures, 7 tables, accepted for publication in MNRA
Ultra-reliable Low-latency, Energy-efficient and Computing-centric Software Data Plane for Network Softwarization
Network softwarization plays a significantly important role in the development and deployment of the latest communication system for 5G and beyond. A more flexible and intelligent network architecture can be enabled to provide support for agile network management, rapid launch of innovative network services with much reduction in Capital Expense (CAPEX) and Operating Expense (OPEX). Despite these benefits, 5G system also raises unprecedented challenges as emerging machine-to-machine and human-to-machine communication use cases require Ultra-Reliable Low Latency Communication (URLLC). According to empirical measurements performed by the author of this dissertation on a practical testbed, State of the Art (STOA) technologies and systems are not able to achieve the one millisecond end-to-end latency requirement of the 5G standard on Commercial Off-The-Shelf (COTS) servers. This dissertation performs a comprehensive introduction to three innovative approaches that can be used to improve different aspects of the current software-driven network data plane. All three approaches are carefully designed, professionally implemented and rigorously evaluated. According to the measurement results, these novel approaches put forward the research in the design and implementation of ultra-reliable low-latency, energy-efficient and computing-first software data plane for 5G communication system and beyond
The Agrarian Legacy: A Study of Political Structure and Ideology in Modern China
A thesis presented to the faculty of the College of Education and Behavioral Sciences at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Arts in Sociology by Zuo Xiang in December of 1992
The power of indirect social ties
While direct social ties have been intensely studied in the context of
computer-mediated social networks, indirect ties (e.g., friends of friends)
have seen little attention. Yet in real life, we often rely on friends of our
friends for recommendations (of good doctors, good schools, or good
babysitters), for introduction to a new job opportunity, and for many other
occasional needs. In this work we attempt to 1) quantify the strength of
indirect social ties, 2) validate it, and 3) empirically demonstrate its
usefulness for distributed applications on two examples. We quantify social
strength of indirect ties using a(ny) measure of the strength of the direct
ties that connect two people and the intuition provided by the sociology
literature. We validate the proposed metric experimentally by comparing
correlations with other direct social tie evaluators. We show via data-driven
experiments that the proposed metric for social strength can be used
successfully for social applications. Specifically, we show that it alleviates
known problems in friend-to-friend storage systems by addressing two previously
documented shortcomings: reduced set of storage candidates and data
availability correlations. We also show that it can be used for predicting the
effects of a social diffusion with an accuracy of up to 93.5%.Comment: Technical Repor
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