24,981 research outputs found
Data Mining to Uncover Heterogeneous Water Use Behaviors From Smart Meter Data
Knowledge on the determinants and patterns of water demand for different consumers supports the design of customized demand management strategies. Smart meters coupled with big data analytics tools create a unique opportunity to support such strategies. Yet, at present, the information content of smart meter data is not fully mined and usually needs to be complemented with water fixture inventory and survey data to achieve detailed customer segmentation based on end use water usage. In this paper, we developed a dataâdriven approach that extracts information on heterogeneous water end use routines, main end use components, and temporal characteristics, only via data mining existing smart meter readings at the scale of individual households. We tested our approach on data from 327 households in Australia, each monitored with smart meters logging water use readings every 5 s. As part of the approach, we first disaggregated the householdâlevel water use time series into different end uses via Autoflow. We then adapted a customer segmentation based on eigenbehavior analysis to discriminate among heterogeneous water end use routines and identify clusters of consumers presenting similar routines. Results revealed three main water end use profile clusters, each characterized by a primary end use: shower, clothes washing, and irrigation. Timeâofâuse and intensityâofâuse differences exist within each class, as well as different characteristics of regularity and periodicity over time. Our customer segmentation analysis approach provides utilities with a concise snapshot of recurrent water use routines from smart meter data and can be used to support customized demand management strategies.TU Berlin, Open-Access-Mittel - 201
Do we really need to catch them all? A new User-guided Social Media Crawling method
With the growing use of popular social media services like Facebook and
Twitter it is challenging to collect all content from the networks without
access to the core infrastructure or paying for it. Thus, if all content cannot
be collected one must consider which data are of most importance. In this work
we present a novel User-guided Social Media Crawling method (USMC) that is able
to collect data from social media, utilizing the wisdom of the crowd to decide
the order in which user generated content should be collected to cover as many
user interactions as possible. USMC is validated by crawling 160 public
Facebook pages, containing content from 368 million users including 1.3 billion
interactions, and it is compared with two other crawling methods. The results
show that it is possible to cover approximately 75% of the interactions on a
Facebook page by sampling just 20% of its posts, and at the same time reduce
the crawling time by 53%. In addition, the social network constructed from the
20% sample contains more than 75% of the users and edges compared to the social
network created from all posts, and it has similar degree distribution
Enhancing Employee Communication Behaviors for Sensemaking and Sensegiving in Crisis Situations: Strategic Management Approach for Effective Internal Crisis Communication
Purpose
The purpose of this paper is to explore the organizational effectiveness of internal crisis communication within the strategic management approach, whether it enhanced voluntary and positive employee communication behaviors (ECBs) for sensemaking and sensegiving. By doing so, this study provides meaningful insight into: new crisis communication theory development that takes a strategic management approach, emphasizing employeesâ valuable assets from an organization, and effective crisis communication practice that reduces misalignment with employees and that enhances voluntary and positive ECBs for the organization during a crisis. Design/methodology/approach
This study conducted a nationwide survey in the USA among full-time employees (n=544). After dimensionality check through confirmatory factor analysis, this study tested hypothesis and research question by conducting ordinary least squares multiple regression analyses using STATA 13. Findings
This study found that strategic internal communication factors, including two-way symmetrical communication and transparent communication, were positive and strong antecedents of ECBs for sensemaking and sensegiving in crisis situations, when controlling for other effects. The post hoc analysis confirmed theses positive and strong associations across different industry areas. Originality/value
This study suggests that voluntary and valuable ECBs can be enhanced by listening and responding to employee concerns and interests; encouraging employee participation in crisis communication; and organizational accountability through words, actions and decisions during the crisis. As a theoretical implication, the results of this study indicate the need for crisis communication theories that emphasize employees as valuable assets to an organization
FLASH: Randomized Algorithms Accelerated over CPU-GPU for Ultra-High Dimensional Similarity Search
We present FLASH (\textbf{F}ast \textbf{L}SH \textbf{A}lgorithm for
\textbf{S}imilarity search accelerated with \textbf{H}PC), a similarity search
system for ultra-high dimensional datasets on a single machine, that does not
require similarity computations and is tailored for high-performance computing
platforms. By leveraging a LSH style randomized indexing procedure and
combining it with several principled techniques, such as reservoir sampling,
recent advances in one-pass minwise hashing, and count based estimations, we
reduce the computational and parallelization costs of similarity search, while
retaining sound theoretical guarantees.
We evaluate FLASH on several real, high-dimensional datasets from different
domains, including text, malicious URL, click-through prediction, social
networks, etc. Our experiments shed new light on the difficulties associated
with datasets having several million dimensions. Current state-of-the-art
implementations either fail on the presented scale or are orders of magnitude
slower than FLASH. FLASH is capable of computing an approximate k-NN graph,
from scratch, over the full webspam dataset (1.3 billion nonzeros) in less than
10 seconds. Computing a full k-NN graph in less than 10 seconds on the webspam
dataset, using brute-force (), will require at least 20 teraflops. We
provide CPU and GPU implementations of FLASH for replicability of our results
Discrete Multi-modal Hashing with Canonical Views for Robust Mobile Landmark Search
Mobile landmark search (MLS) recently receives increasing attention for its
great practical values. However, it still remains unsolved due to two important
challenges. One is high bandwidth consumption of query transmission, and the
other is the huge visual variations of query images sent from mobile devices.
In this paper, we propose a novel hashing scheme, named as canonical view based
discrete multi-modal hashing (CV-DMH), to handle these problems via a novel
three-stage learning procedure. First, a submodular function is designed to
measure visual representativeness and redundancy of a view set. With it,
canonical views, which capture key visual appearances of landmark with limited
redundancy, are efficiently discovered with an iterative mining strategy.
Second, multi-modal sparse coding is applied to transform visual features from
multiple modalities into an intermediate representation. It can robustly and
adaptively characterize visual contents of varied landmark images with certain
canonical views. Finally, compact binary codes are learned on intermediate
representation within a tailored discrete binary embedding model which
preserves visual relations of images measured with canonical views and removes
the involved noises. In this part, we develop a new augmented Lagrangian
multiplier (ALM) based optimization method to directly solve the discrete
binary codes. We can not only explicitly deal with the discrete constraint, but
also consider the bit-uncorrelated constraint and balance constraint together.
Experiments on real world landmark datasets demonstrate the superior
performance of CV-DMH over several state-of-the-art methods
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