6,046 research outputs found
Characterizing Location-based Mobile Tracking in Mobile Ad Networks
Mobile apps nowadays are often packaged with third-party ad libraries to
monetize user data
Profiling user activities with minimal traffic traces
Understanding user behavior is essential to personalize and enrich a user's
online experience. While there are significant benefits to be accrued from the
pursuit of personalized services based on a fine-grained behavioral analysis,
care must be taken to address user privacy concerns. In this paper, we consider
the use of web traces with truncated URLs - each URL is trimmed to only contain
the web domain - for this purpose. While such truncation removes the
fine-grained sensitive information, it also strips the data of many features
that are crucial to the profiling of user activity. We show how to overcome the
severe handicap of lack of crucial features for the purpose of filtering out
the URLs representing a user activity from the noisy network traffic trace
(including advertisement, spam, analytics, webscripts) with high accuracy. This
activity profiling with truncated URLs enables the network operators to provide
personalized services while mitigating privacy concerns by storing and sharing
only truncated traffic traces.
In order to offset the accuracy loss due to truncation, our statistical
methodology leverages specialized features extracted from a group of
consecutive URLs that represent a micro user action like web click, chat reply,
etc., which we call bursts. These bursts, in turn, are detected by a novel
algorithm which is based on our observed characteristics of the inter-arrival
time of HTTP records. We present an extensive experimental evaluation on a real
dataset of mobile web traces, consisting of more than 130 million records,
representing the browsing activities of 10,000 users over a period of 30 days.
Our results show that the proposed methodology achieves around 90% accuracy in
segregating URLs representing user activities from non-representative URLs
Deep Learning in the Automotive Industry: Applications and Tools
Deep Learning refers to a set of machine learning techniques that utilize
neural networks with many hidden layers for tasks, such as image
classification, speech recognition, language understanding. Deep learning has
been proven to be very effective in these domains and is pervasively used by
many Internet services. In this paper, we describe different automotive uses
cases for deep learning in particular in the domain of computer vision. We
surveys the current state-of-the-art in libraries, tools and infrastructures
(e.\,g.\ GPUs and clouds) for implementing, training and deploying deep neural
networks. We particularly focus on convolutional neural networks and computer
vision use cases, such as the visual inspection process in manufacturing plants
and the analysis of social media data. To train neural networks, curated and
labeled datasets are essential. In particular, both the availability and scope
of such datasets is typically very limited. A main contribution of this paper
is the creation of an automotive dataset, that allows us to learn and
automatically recognize different vehicle properties. We describe an end-to-end
deep learning application utilizing a mobile app for data collection and
process support, and an Amazon-based cloud backend for storage and training.
For training we evaluate the use of cloud and on-premises infrastructures
(including multiple GPUs) in conjunction with different neural network
architectures and frameworks. We assess both the training times as well as the
accuracy of the classifier. Finally, we demonstrate the effectiveness of the
trained classifier in a real world setting during manufacturing process.Comment: 10 page
Privacy-Friendly Mobility Analytics using Aggregate Location Data
Location data can be extremely useful to study commuting patterns and
disruptions, as well as to predict real-time traffic volumes. At the same time,
however, the fine-grained collection of user locations raises serious privacy
concerns, as this can reveal sensitive information about the users, such as,
life style, political and religious inclinations, or even identities. In this
paper, we study the feasibility of crowd-sourced mobility analytics over
aggregate location information: users periodically report their location, using
a privacy-preserving aggregation protocol, so that the server can only recover
aggregates -- i.e., how many, but not which, users are in a region at a given
time. We experiment with real-world mobility datasets obtained from the
Transport For London authority and the San Francisco Cabs network, and present
a novel methodology based on time series modeling that is geared to forecast
traffic volumes in regions of interest and to detect mobility anomalies in
them. In the presence of anomalies, we also make enhanced traffic volume
predictions by feeding our model with additional information from correlated
regions. Finally, we present and evaluate a mobile app prototype, called
Mobility Data Donors (MDD), in terms of computation, communication, and energy
overhead, demonstrating the real-world deployability of our techniques.Comment: Published at ACM SIGSPATIAL 201
adPerf: Characterizing the Performance of Third-party Ads
Monetizing websites and web apps through online advertising is widespread in
the web ecosystem. The online advertising ecosystem nowadays forces publishers
to integrate ads from these third-party domains. On the one hand, this raises
several privacy and security concerns that are actively studied in recent
years. On the other hand, given the ability of today's browsers to load dynamic
web pages with complex animations and Javascript, online advertising has also
transformed and can have a significant impact on webpage performance. The
performance cost of online ads is critical since it eventually impacts user
satisfaction as well as their Internet bill and device energy consumption.
In this paper, we apply an in-depth and first-of-a-kind performance
evaluation of web ads. Unlike prior efforts that rely primarily on adblockers,
we perform a fine-grained analysis on the web browser's page loading process to
demystify the performance cost of web ads. We aim to characterize the cost by
every component of an ad, so the publisher, ad syndicate, and advertiser can
improve the ad's performance with detailed guidance. For this purpose, we
develop an infrastructure, adPerf, for the Chrome browser that classifies page
loading workloads into ad-related and main-content at the granularity of
browser activities (such as Javascript and Layout). Our evaluations show that
online advertising entails more than 15% of browser page loading workload and
approximately 88% of that is spent on JavaScript. We also track the sources and
delivery chain of web ads and analyze performance considering the origin of the
ad contents. We observe that 2 of the well-known third-party ad domains
contribute to 35% of the ads performance cost and surprisingly, top news
websites implicitly include unknown third-party ads which in some cases build
up to more than 37% of the ads performance cost
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