62,310 research outputs found
Distance Education Research in Adult Education Journals: A Content Analysis
This study examines adult-centered distance education research articles in two adult education journals: Adult Education Quarterly and the American Journal of Distance Education. Results show that studies of delivery modes and systems; i.e., asynchronous and synchronous modes, learning management systems, television and Web delivery, and course design were most prevalent in both journals. Among topics of interest to adult educators, the self-directed nature of distance learning was predominant. Other topics traditionally associated with adult education, such as access, equity, and social change themes in distance education, were least prevalent in both journals
Experimental evaluation in wireless communications
This editorial sums up relevant topics on the assessment of wireless communication systems covered by the especial issue entitled "Experimental Evaluation in Wireless Communications". The topics include practical aspects on the implementation of distributed asynchronous non-linear kernel methods over wireless sensor networks; localization methods based on the exploitation of radio-frequency identification (RFID) wireless sensors and cellular networks or on sparsity approximations; channel sounding and assessment of broadband orthogonal frequency-division multiplexing (OFDM)-based wireless systems in high-speed vehicular communications; coexistence analysis of femtocell-based and outdoor-to-indoor systems; techniques for peak-to-average power ratio (PAPR) reduction; new solutions for baseband and radio frequency (RF) hardware impairments in full-duplex wireless systems; and, finally, suitability of interference alignment for broadband indoor wireless communications
Computing Web-scale Topic Models using an Asynchronous Parameter Server
Topic models such as Latent Dirichlet Allocation (LDA) have been widely used
in information retrieval for tasks ranging from smoothing and feedback methods
to tools for exploratory search and discovery. However, classical methods for
inferring topic models do not scale up to the massive size of today's publicly
available Web-scale data sets. The state-of-the-art approaches rely on custom
strategies, implementations and hardware to facilitate their asynchronous,
communication-intensive workloads.
We present APS-LDA, which integrates state-of-the-art topic modeling with
cluster computing frameworks such as Spark using a novel asynchronous parameter
server. Advantages of this integration include convenient usage of existing
data processing pipelines and eliminating the need for disk writes as data can
be kept in memory from start to finish. Our goal is not to outperform highly
customized implementations, but to propose a general high-performance topic
modeling framework that can easily be used in today's data processing
pipelines. We compare APS-LDA to the existing Spark LDA implementations and
show that our system can, on a 480-core cluster, process up to 135 times more
data and 10 times more topics without sacrificing model quality.Comment: To appear in SIGIR 201
Holistic engineering design : a combined synchronous and asynchronous approach
To aid the creation and through-life support of large, complex engineering products, organizations are placing a greater emphasis on constructing complete and accurate records of design activities. Current documentary approaches are not sufficient to capture activities and decisions in their entirety and can lead to organizations revisiting and in some cases reworking design decisions in order to understand previous design episodes. Design activities are undertaken in a variety of modes; many of which are dichotomous, and thus each require separate documentary mechanisms to capture information in an efficient manner. It is possible to identify the modes of learning and transaction to describe whether an activity is aimed at increasing a level of understanding or whether it involves manipulating information to achieve a tangible task. The dichotomy of interest in this paper is that of synchronous and asynchronous working, where engineers may work alternately as part of a group or as individuals and where different forms of record are necessary to adequately capture the processes and rationale employed in each mode. This paper introduces complimentary approaches to achieving richer representations of design activities performed synchronously and asynchronously, and through the undertaking of a design based case study, highlights the benefit of each approach. The resulting records serve to provide a more complete depiction of activities undertaken, and provide positive direction for future co-development of the approaches
A Scalable Asynchronous Distributed Algorithm for Topic Modeling
Learning meaningful topic models with massive document collections which
contain millions of documents and billions of tokens is challenging because of
two reasons: First, one needs to deal with a large number of topics (typically
in the order of thousands). Second, one needs a scalable and efficient way of
distributing the computation across multiple machines. In this paper we present
a novel algorithm F+Nomad LDA which simultaneously tackles both these problems.
In order to handle large number of topics we use an appropriately modified
Fenwick tree. This data structure allows us to sample from a multinomial
distribution over items in time. Moreover, when topic counts
change the data structure can be updated in time. In order to
distribute the computation across multiple processor we present a novel
asynchronous framework inspired by the Nomad algorithm of
\cite{YunYuHsietal13}. We show that F+Nomad LDA significantly outperform
state-of-the-art on massive problems which involve millions of documents,
billions of words, and thousands of topics
Informal Online Decision Making: Current Practices and Support System Design
Existing group decision support systems are too complex to support lightweight, informal decision making made popular by the amount of information available on the Web. From an examination of related work, an online survey and a formative study to examine how people currently use the Web for decision support, we present a set of design recommendations towards the development of an informal Web decision support tool
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