15,202 research outputs found
Communication with Chinese International Students: Understanding Chinese International Students’ learning difficulties and communication barriers
The problems of communication with Chinese international students are reported in many academic publications related to international students in higher education in the UK. Majority of these problems links to teaching and learning activities: Chinese international students are quiet in classroom, not active in group discussion or group work, and passive in tutorials etc. Such problems not only cause misunderstandings between Chinese international students and their tutors but also have negative influence on their learning outcome. This article is based on an empirical study on Chinese international students’ learning experience in University of Huddersfield. 34 Chinese international students from foundation to PhD participate in focus group discussion and personal interview. The participants generally have learning difficulties to some degree, which associate to their communication problems. English proficiency is not a primary factor cause their learning difficulties. External and internal communication and cultural barriers are the key factors behind Chinese international students learning difficulties. The findings of the research can help academic tutors in higher education understand where the communication problems with Chinese international students come from and how to resolve these problems
Listen-and-Talk: Full-duplex Cognitive Radio Networks
In traditional cognitive radio networks, secondary users (SUs) typically
access the spectrum of primary users (PUs) by a two-stage "listen-before-talk"
(LBT) protocol, i.e., SUs sense the spectrum holes in the first stage before
transmit in the second stage. In this paper, we propose a novel
"listen-and-talk" (LAT) protocol with the help of the full-duplex (FD)
technique that allows SUs to simultaneously sense and access the vacant
spectrum. Analysis of sensing performance and SU's throughput are given for the
proposed LAT protocol. And we find that due to self-interference caused by FD,
increasing transmitting power of SUs does not always benefit to SU's
throughput, which implies the existence of a power-throughput tradeoff.
Besides, though the LAT protocol suffers from self-interference, it allows
longer transmission time, while the performance of the traditional LBT protocol
is limited by channel spatial correction and relatively shorter transmission
period. To this end, we also present an adaptive scheme to improve SUs'
throughput by switching between the LAT and LBT protocols. Numerical results
are provided to verify the proposed methods and the theoretical results.Comment: in proceeding of IEEE Globecom 201
Full-duplex MAC Protocol Design and Analysis
The idea of in-band full-duplex (FD) communications revives in recent years
owing to the significant progress in the self-interference cancellation and
hardware design techniques, offering the potential to double spectral
efficiency. The adaptations in upper layers are highly demanded in the design
of FD communication systems. In this letter, we propose a novel medium access
control (MAC) using FD techniques that allows transmitters to monitor the
channel usage while transmitting, and backoff as soon as collision happens.
Analytical saturation throughput of the FD-MAC protocol is derived with the
consideration of imperfect sensing brought by residual self- interference (RSI)
in the PHY layer. Both analytical and simulation results indicate that the
normalized saturation throughput of the proposed FD-MAC can significantly
outperforms conventional CSMA/CA under various network conditions
A Quadratically Regularized Functional Canonical Correlation Analysis for Identifying the Global Structure of Pleiotropy with NGS Data
Investigating the pleiotropic effects of genetic variants can increase
statistical power, provide important information to achieve deep understanding
of the complex genetic structures of disease, and offer powerful tools for
designing effective treatments with fewer side effects. However, the current
multiple phenotype association analysis paradigm lacks breadth (number of
phenotypes and genetic variants jointly analyzed at the same time) and depth
(hierarchical structure of phenotype and genotypes). A key issue for high
dimensional pleiotropic analysis is to effectively extract informative internal
representation and features from high dimensional genotype and phenotype data.
To explore multiple levels of representations of genetic variants, learn their
internal patterns involved in the disease development, and overcome critical
barriers in advancing the development of novel statistical methods and
computational algorithms for genetic pleiotropic analysis, we proposed a new
framework referred to as a quadratically regularized functional CCA (QRFCCA)
for association analysis which combines three approaches: (1) quadratically
regularized matrix factorization, (2) functional data analysis and (3)
canonical correlation analysis (CCA). Large-scale simulations show that the
QRFCCA has a much higher power than that of the nine competing statistics while
retaining the appropriate type 1 errors. To further evaluate performance, the
QRFCCA and nine other statistics are applied to the whole genome sequencing
dataset from the TwinsUK study. We identify a total of 79 genes with rare
variants and 67 genes with common variants significantly associated with the 46
traits using QRFCCA. The results show that the QRFCCA substantially outperforms
the nine other statistics.Comment: 64 pages including 12 figure
Full-Duplex Cognitive Radio: A New Design Paradigm for Enhancing Spectrum Usage
With the rapid growth of demand for ever-increasing data rate, spectrum
resources have become more and more scarce. As a promising technique to
increase the efficiency of the spectrum utilization, cognitive radio (CR)
technique has the great potential to meet such a requirement by allowing
un-licensed users to coexist in licensed bands. In conventional CR systems, the
spectrum sensing is performed at the beginning of each time slot before the
data transmission. This unfortunately results in two major problems: 1)
transmission time reduction due to sensing, and 2) sensing accuracy impairment
due to data transmission. To tackle these problems, in this paper we present a
new design paradigm for future CR by exploring the full-duplex (FD) techniques
to achieve the simultaneous spectrum sensing and data transmission. With FD
radios equipped at the secondary users (SUs), SUs can simultaneously sense and
access the vacant spectrum, and thus, significantly improve sensing
performances and meanwhile increase data transmission efficiency. The aim of
this article is to transform the promising conceptual framework into the
practical wireless network design by addressing a diverse set of challenges
such as protocol design and theoretical analysis. Several application scenarios
with FD enabled CR are elaborated, and key open research directions and novel
algorithms in these systems are discussed
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