5,395 research outputs found
Robust And Optimal Opportunistic Scheduling For Downlink 2-Flow Network Coding With Varying Channel Quality and Rate Adaptation
This paper considers the downlink traffic from a base station to two
different clients. When assuming infinite backlog, it is known that
inter-session network coding (INC) can significantly increase the throughput of
each flow. However, the corresponding scheduling solution (when assuming
dynamic arrivals instead and requiring bounded delay) is still nascent.
For the 2-flow downlink scenario, we propose the first opportunistic INC +
scheduling solution that is provably optimal for time-varying channels, i.e.,
the corresponding stability region matches the optimal Shannon capacity.
Specifically, we first introduce a new binary INC operation, which is
distinctly different from the traditional wisdom of XORing two overheard
packets. We then develop a queue-length-based scheduling scheme, which, with
the help of the new INC operation, can robustly and optimally adapt to
time-varying channel quality. We then show that the proposed algorithm can be
easily extended for rate adaptation and it again robustly achieves the optimal
throughput. A byproduct of our results is a scheduling scheme for stochastic
processing networks (SPNs) with random departure, which relaxes the assumption
of deterministic departure in the existing results. The new SPN scheduler could
thus further broaden the applications of SPN scheduling to other real-world
scenarios
God, Western Learning, and Personal Memento: Timothy Richard’s Literary Work in Late Imperial China
This dissertation examines the China missionary Timothy Richard’s literary work by discussing how he utilized periodical publications to achieve goals in his life and career. Literary work, according to Richard, means using publication in newspapers to promote Christianity and Western learning. Richard served as the secretary of the Society for the Diffusion of Christian and General Knowledge Among the Chinese (the S.D.C.K.) from 1891 to 1915. When working in the S.D.C.K., he met the time that China started to embrace Western learning. Achieving successful literary work, Richard engaged in both Chinese and English publications so as to balance between Chinese readers, i.e. Chinese officials and intellectuals, and English readers, i.e. missionary groups in China and readers in the U.K. His literary work helped him to achieve the goal of promoting China’s modernization and spreading Christianity at the same time. The present research uses Richard’s life as the framework to discuss his efforts at literary work, so as to show how it developed in his every stage of life. In his early age, Richard regarded the media as a tool to express God’s blessing on mankind, preaching the Gospel among the Chinese; in his midlife, he utilized publication in newspapers to introduce Western learning for China; in his old age, media became a spiritual sustenance which he came to rely on. Through his literary work, Richard not only helped China to understand Western civilization, especially with regard to science and technology, but also made the British further understand China, promoting cultural interactions between the Far East and the West
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