172,998 research outputs found
Finding Associations and Computing Similarity via Biased Pair Sampling
This version is ***superseded*** by a full version that can be found at
http://www.itu.dk/people/pagh/papers/mining-jour.pdf, which contains stronger
theoretical results and fixes a mistake in the reporting of experiments.
Abstract: Sampling-based methods have previously been proposed for the
problem of finding interesting associations in data, even for low-support
items. While these methods do not guarantee precise results, they can be vastly
more efficient than approaches that rely on exact counting. However, for many
similarity measures no such methods have been known. In this paper we show how
a wide variety of measures can be supported by a simple biased sampling method.
The method also extends to find high-confidence association rules. We
demonstrate theoretically that our method is superior to exact methods when the
threshold for "interesting similarity/confidence" is above the average pairwise
similarity/confidence, and the average support is not too low. Our method is
particularly good when transactions contain many items. We confirm in
experiments on standard association mining benchmarks that this gives a
significant speedup on real data sets (sometimes much larger than the
theoretical guarantees). Reductions in computation time of over an order of
magnitude, and significant savings in space, are observed.Comment: This is an extended version of a paper that appeared at the IEEE
International Conference on Data Mining, 2009. The conference version is (c)
2009 IEE
Industry 4.0 in the Theme Park Sector: Design of a RealTime Monitoring System for Queue Management
The theme park industry is a consolidated sector where different industrial technologies and management procedures are present. However, the Industry 4.0 paradigm aims at disrupting how industrial processes are conceived. In this thesis, we perform a thorough investigation of key relevant features of theme parks and how industry 4.0 could be applied within the theme park sector.
Our methodology is as follows. First, we analyse the technology used in the most innovative attractions. Afterwards, we focus on the most recurrent problem within the sector: queue management at attractions. As part of the solution, a system is designed to allow real-time monitoring of waiting times through an IoT infrastructure. Radio Fre-
quency Identification and Bluetooth Low Energy are the chosen technologies for people counting. They allow users to be located in the park in addition to counting. This system gives precise waiting times estimates, and park managers can obtain precious data about
user behaviour and preferences.
Finally, we develop a proof of concept to test the designed solution and detail the benefits of applying industry 4.0 to the theme park sector.Máster en Industria Conectada 4.
Electronic Voting: the Devil is in the Details
Observing electronic voting from an international point of view gives some
perspective about its genesis and evolution. An analysis of the voting process
through its cultural, ontological, legal and political dimensions explains the
difficulty to normalize this process. It appears that international
organizations are not capable to properly defend the fundamental rights of the
citizens. The approach that was taken when DRE voting computers appeared seems
to have reoccured with VVAT voting computers and the european e-poll project.Comment: 9 page
The Visual Social Distancing Problem
One of the main and most effective measures to contain the recent viral
outbreak is the maintenance of the so-called Social Distancing (SD). To comply
with this constraint, workplaces, public institutions, transports and schools
will likely adopt restrictions over the minimum inter-personal distance between
people. Given this actual scenario, it is crucial to massively measure the
compliance to such physical constraint in our life, in order to figure out the
reasons of the possible breaks of such distance limitations, and understand if
this implies a possible threat given the scene context. All of this, complying
with privacy policies and making the measurement acceptable. To this end, we
introduce the Visual Social Distancing (VSD) problem, defined as the automatic
estimation of the inter-personal distance from an image, and the
characterization of the related people aggregations. VSD is pivotal for a
non-invasive analysis to whether people comply with the SD restriction, and to
provide statistics about the level of safety of specific areas whenever this
constraint is violated. We then discuss how VSD relates with previous
literature in Social Signal Processing and indicate which existing Computer
Vision methods can be used to manage such problem. We conclude with future
challenges related to the effectiveness of VSD systems, ethical implications
and future application scenarios.Comment: 9 pages, 5 figures. All the authors equally contributed to this
manuscript and they are listed by alphabetical order. Under submissio
Occupancy Estimation Using Low-Cost Wi-Fi Sniffers
Real-time measurements on the occupancy status of indoor and outdoor spaces
can be exploited in many scenarios (HVAC and lighting system control, building
energy optimization, allocation and reservation of spaces, etc.). Traditional
systems for occupancy estimation rely on environmental sensors (CO2,
temperature, humidity) or video cameras. In this paper, we depart from such
traditional approaches and propose a novel occupancy estimation system which is
based on the capture of Wi-Fi management packets from users' devices. The
system, implemented on a low-cost ESP8266 microcontroller, leverages a
supervised learning model to adapt to different spaces and transmits occupancy
information through the MQTT protocol to a web-based dashboard. Experimental
results demonstrate the validity of the proposed solution in four different
indoor university spaces.Comment: Submitted to Balkancom 201
System Energy Assessment (SEA), Defining a Standard Measure of EROI for Energy Businesses as Whole Systems
A more objective method for measuring the energy needs of businesses, System
Energy Assessment (SEA), identifies the natural boundaries of businesses as
self-managing net-energy systems, of controlled and self-managing parts. The
method is demonstrated using a model Wind Farm case study, and applied to
defining a true physical measure of its energy productivity for society
(EROI-S), the global ratio of energy produced to energy cost. The traceable
needs of business technology are combined with assignable energy needs for all
other operating services. That serves to correct a large natural gap in energy
use information. Current methods count traceable energy receipts for technology
use. Self-managing services employed by businesses outsource their own energy
needs to operate, and leave no records to trace. Those uncounted energy demands
are often 80% of the total embodied energy of business end products. The scale
of this "dark energy" was discovered from differing global accounts, and
corrected so the average energy cost per dollar for businesses would equal the
world average energy use per dollar of GDP. Presently the energy needs of paid
services that outsource their own energy needs are counted for lack of
information to be "0". Our default assumption is to treat them as "average".
The result is to assign total energy use and impacts to the demand for energy
services, for a "Scope 4" GHG assessment level. Counting only the energy uses
of technology understates the energy needs of business services, as if services
were more energy efficient than technology. The result confirms a similar
finding by Hall et. al. in 1981 [9]. We use exhaustive search for what a
business needs to operate as a whole, locating a natural physical boundary for
its working parts, to define businesses as physical rather than statistical
subjects of science. :measurement, natural systemsComment: 33 pages, 15 figures, accepted as part of pending special issue on
EROI organized by Charlie Hall for Sustainability (MDPI
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