157 research outputs found
Curricular Analytics in Higher Education
The dissertation addresses different aspects of student success in higher education. Numerous factors may impact a student\u27s ability to succeed and ultimately graduate, including pre-university preparation, as well as the student support services provided by a university. However, even the best efforts to improve in these areas may fail if other institutional factors overwhelm their ability to facilitate student progress. This dissertation addresses this issue from the perspective of curriculum structure. The structural properties of individual curricula are studied, and the extent to which this structure impacts student progress is explored. The structure of curricula are studied using actual university data and analyzed by applying different data mining techniques, machine learning methods and graph theory. These techniques and methods provide a mathematical tool to quantify the complexity of a curriculum structure. The results presented in this work show that there is an inverse correlation between the complexity of a curriculum and the graduation rate of students attempting that curriculum. To make it more practical, this study was extended further to implement a number of predictive models that give colleges and universities the ability to track the progress of their students in order to improve retention and graduation rates. These models accurately predict the performance of students in subsequent terms and accordingly could be used to provide early intervention alerts. The dissertation addresses another important aspect related to curricula. Specifically, how course enrollment sequences in a curriculum impact student progress. Thus, graduation rates could be improved by directing students to follow better course sequences. The novelty of the models presented in this dissertation is characterized in introducing graduation rate, for the first time in literature, from the perspective of curricular complexity. This provides the faculty and staff the ability to better advise students earlier in their academic careers
In-Band Full-Duplex Communications for Cellular Networks with Partial Uplink/Downlink Overlap
In-band full-duplex (FD) communications have been optimistically promoted to
improve the spectrum utilization in cellular networks. However, the explicit
impact of spatial interference, imposed by FD communications, on uplink and
downlink transmissions has been overlooked in the literature. This paper
presents an extensive study of the explicit effect of FD communications on the
uplink and downlink performances. For the sake of rigorous analysis, we develop
a tractable framework based on stochastic geometry toolset. The developed model
accounts for uplink truncated channel inversion power control in FD cellular
networks. The study shows that FD communications improve the downlink
throughput at the expense of significant degradation in the uplink throughput.
Therefore, we propose a novel fine-grained duplexing scheme, denoted as
-duplex scheme, which allows a partial overlap between uplink and
downlink frequency bands. To this end, we show that the amount of the overlap
can be optimized via adjusting to achieve a certain design objective.Comment: To be presented in IEEE Globecom 201
Modeling Cellular Networks in Fading Environments with Dominant Specular Components
Stochastic geometry (SG) has been widely accepted as a fundamental tool for
modeling and analyzing cellular networks. However, the fading models used with
SG analysis are mainly confined to the simplistic Rayleigh fading, which is
extended to the Nakagami-m fading in some special cases. However, neither the
Rayleigh nor the Nakagami-m accounts for dominant specular components (DSCs)
which may appear in realistic fading channels. In this paper, we present a
tractable model for cellular networks with generalized two-ray (GTR) fading
channel. The GTR fading explicitly accounts for two DSCs in addition to the
diffuse components and offers high flexibility to capture diverse fading
channels that appear in realistic outdoor/indoor wireless communication
scenarios. It also encompasses the famous Rayleigh and Rician fading as special
cases. To this end, the prominent effect of DSCs is highlighted in terms of
average spectral efficiency.Comment: IEEE ICC1
Green Networking in Cellular HetNets: A Unified Radio Resource Management Framework with Base Station ON/OFF Switching
In this paper, the problem of energy efficiency in cellular heterogeneous
networks (HetNets) is investigated using radio resource and power management
combined with the base station (BS) ON/OFF switching. The objective is to
minimize the total power consumption of the network while satisfying the
quality of service (QoS) requirements of each connected user. We consider the
case of co-existing macrocell BS, small cell BSs, and private femtocell access
points (FAPs). Three different network scenarios are investigated, depending on
the status of the FAPs, i.e., HetNets without FAPs, HetNets with closed FAPs,
and HetNets with semi-closed FAPs. A unified framework is proposed to
simultaneously allocate spectrum resources to users in an energy efficient
manner and switch off redundant small cell BSs. The high complexity dual
decomposition technique is employed to achieve optimal solutions for the
problem. A low complexity iterative algorithm is also proposed and its
performances are compared to those of the optimal technique. The particularly
interesting case of semi-closed FAPs, in which the FAPs accept to serve
external users, achieves the highest energy efficiency due to increased degrees
of freedom. In this paper, a cooperation scheme between FAPs and mobile
operator is also investigated. The incentives for FAPs, e.g., renewable energy
sharing and roaming prices, enabling cooperation are discussed to be considered
as a useful guideline for inter-operator agreements.Comment: 15 pages, 9 Figures, IEEE Transactions on Vehicular Technology 201
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