1,978 research outputs found
Spatial-temporal data mining procedure: LASR
This paper is concerned with the statistical development of our
spatial-temporal data mining procedure, LASR (pronounced ``laser''). LASR is
the abbreviation for Longitudinal Analysis with Self-Registration of
large--small- data. It was motivated by a study of ``Neuromuscular
Electrical Stimulation'' experiments, where the data are noisy and
heterogeneous, might not align from one session to another, and involve a large
number of multiple comparisons. The three main components of LASR are: (1) data
segmentation for separating heterogeneous data and for distinguishing outliers,
(2) automatic approaches for spatial and temporal data registration, and (3)
statistical smoothing mapping for identifying ``activated'' regions based on
false-discovery-rate controlled -maps and movies. Each of the components is
of interest in its own right. As a statistical ensemble, the idea of LASR is
applicable to other types of spatial-temporal data sets beyond those from the
NMES experiments.Comment: Published at http://dx.doi.org/10.1214/074921706000000707 in the IMS
Lecture Notes--Monograph Series
(http://www.imstat.org/publications/lecnotes.htm) by the Institute of
Mathematical Statistics (http://www.imstat.org
Spatial-temporal data modelling and processing for personalised decision support
The purpose of this research is to undertake the modelling of dynamic data without losing any of the temporal relationships, and to be able to predict likelihood of outcome as far in advance of actual occurrence as possible. To this end a novel computational architecture for personalised ( individualised) modelling of spatio-temporal data based on spiking neural network methods (PMeSNNr), with a three dimensional visualisation of relationships between variables is proposed. In brief, the architecture is able to transfer spatio-temporal data patterns from a multidimensional input stream into internal patterns in the spiking neural network reservoir. These patterns are then analysed to produce a personalised model for either classification or prediction dependent on the specific needs of the situation. The architecture described above was constructed using MatLab© in several individual modules linked together to form NeuCube (M1). This methodology has been applied to two real world case studies. Firstly, it has been applied to data for the prediction of stroke occurrences on an individual basis. Secondly, it has been applied to ecological data on aphid pest abundance prediction. Two main objectives for this research when judging outcomes of the modelling are accurate prediction and to have this at the earliest possible time point. The implications of these findings are not insignificant in terms of health care management and environmental control. As the case studies utilised here represent vastly different application fields, it reveals more of the potential and usefulness of NeuCube (M1) for modelling data in an integrated manner. This in turn can identify previously unknown (or less understood) interactions thus both increasing the level of reliance that can be placed on the model created, and enhancing our human understanding of the complexities of the world around us without the need for over simplification. Read less
Keywords
Personalised modelling; Spiking neural network; Spatial-temporal data modelling; Computational intelligence; Predictive modelling; Stroke risk predictio
Spatial-temporal data modelling and processing for personalised decision support
The purpose of this research is to undertake the modelling of dynamic data without losing any of the temporal relationships, and to be able to predict likelihood of outcome as far in advance of actual occurrence as possible. To this end a novel computational architecture for personalised ( individualised) modelling of spatio-temporal data based on spiking neural network methods (PMeSNNr), with a three dimensional visualisation of relationships between variables is proposed. In brief, the architecture is able to transfer spatio-temporal data patterns from a multidimensional input stream into internal patterns in the spiking neural network reservoir. These patterns are then analysed to produce a personalised model for either classification or prediction dependent on the specific needs of the situation. The architecture described above was constructed using MatLab© in several individual modules linked together to form NeuCube (M1). This methodology has been applied to two real world case studies. Firstly, it has been applied to data for the prediction of stroke occurrences on an individual basis. Secondly, it has been applied to ecological data on aphid pest abundance prediction. Two main objectives for this research when judging outcomes of the modelling are accurate prediction and to have this at the earliest possible time point. The implications of these findings are not insignificant in terms of health care management and environmental control. As the case studies utilised here represent vastly different application fields, it reveals more of the potential and usefulness of NeuCube (M1) for modelling data in an integrated manner. This in turn can identify previously unknown (or less understood) interactions thus both increasing the level of reliance that can be placed on the model created, and enhancing our human understanding of the complexities of the world around us without the need for over simplification. Read less
Keywords
Personalised modelling; Spiking neural network; Spatial-temporal data modelling; Computational intelligence; Predictive modelling; Stroke risk predictio
Text and Spatial-Temporal Data Visualization
In this dissertation, we discuss a text visualization system, a tree drawing algorithm, a spatial-temporal data visualization paradigm and a tennis match visualization system. Corpus and corpus tools have become an important part of language teaching and learning. And yet text visualization is rarely used in this area. We present Text X-Ray, a Web tool for corpus-based language teaching and learning and the interactive text visualizations in Text X-Ray allow users to quickly examine a corpus or corpora at different levels of details: articles, paragraphs, sentences, and words. Level-based tree drawing is a common algorithm that produces intuitive and clear presentations of hierarchically structured information. However, new applications often introduces new aesthetic requirements that call for new tree drawing methods. We present an indented level-based tree drawing algorithm for visualizing parse trees of English language. This algorithm displays a tree with an aspect ratio that fits the aspect ratio of the newer computer displays, while presenting the words in a way that is easy to read. We discuss the design of the algorithm and its application in text visualization for linguistic analysis and language learning. A story is a chain of events. Each event has multiple dimensions, including time, location, characters, actions, and context. Storyline visualizations attempt to visually present the many dimensions of a story’s events and their relationships. Integrating the temporal and spatial dimension in a single visualization view is often desirable but highly challenging. One of the main reasons is that spatial data is inherently 2D while temporal data is inherently 1D. We present a storyline visualization technique that integrate both time and location information in a single view. Sports data visualization can be a useful tool for analyzing or presenting sports data. We present a new technique for visualizing tennis match data. It is designed as a supplement to online live streaming or live blogging of tennis matches and can retrieve data directly from a tennis match live blogging web site and display 2D interactive view of match statistics. Therefore, it can be easily integrated with the current live blogging platforms used by many news organizations. The visualization addresses the limitations of the current live coverage of tennis matches by providing a quick overview and also a great amount of details on demand
Bayesian Recurrent Neural Network Models for Forecasting and Quantifying Uncertainty in Spatial-Temporal Data
Recurrent neural networks (RNNs) are nonlinear dynamical models commonly used
in the machine learning and dynamical systems literature to represent complex
dynamical or sequential relationships between variables. More recently, as deep
learning models have become more common, RNNs have been used to forecast
increasingly complicated systems. Dynamical spatio-temporal processes represent
a class of complex systems that can potentially benefit from these types of
models. Although the RNN literature is expansive and highly developed,
uncertainty quantification is often ignored. Even when considered, the
uncertainty is generally quantified without the use of a rigorous framework,
such as a fully Bayesian setting. Here we attempt to quantify uncertainty in a
more formal framework while maintaining the forecast accuracy that makes these
models appealing, by presenting a Bayesian RNN model for nonlinear
spatio-temporal forecasting. Additionally, we make simple modifications to the
basic RNN to help accommodate the unique nature of nonlinear spatio-temporal
data. The proposed model is applied to a Lorenz simulation and two real-world
nonlinear spatio-temporal forecasting applications
Evaluation of Shoreline Dynamics Analyzing Spatial Temporal Data
Shoreline change is considered as one of the most dynamic processes in the coastal regions. Shoreline spatial location mentions to several different features such as vegetation line, high water line, low water line, or the wet/dry line. They can be generated from a variety of spatial temporal data sources, like satellite imagery, digital orthophotos, historical coastal-survey maps and field observed spatial data using Global Positioning System. The undertaken work focuses on analysing shoreline dynamics, using spatial temporal data, by taking advantage of Geographic Information System (GIS) and Remote Sensing (RS). Multi year’s shoreline mapping is a valuable method for shoreline monitoring and assessment.
The study area extends from the Port of Shengjin (North), to the delta of Drini river (South), a segment of Drini bay shoreline with a length of about 17 km. The available data used to generate shorelines spatial location include topographic maps at scale 1: 75 000, year 1918 (MGI); topographic maps at scale 1: 50 000, year 1937 ( GMIF); topographic maps at scale 1: 25 000, year 1985 ( AGMI) ; digital orthophotos of year 2007 and field observed GPS data, year 2014. The net rates of variations NSM (Net Shoreline Movement) of the shoreline position are calculated according to transects inclined perpendicularly to the baseline and spaced equally along the coast using DSAS (Digital Shoreline Analysis System). NSM represents the distance between the oldest and youngest shorelines.
Analyses of the data shows that 35% of coastline of study area is in accretion process meanwhile 65% is in erosion process. Maximum rate of erosion is near to the mouth of Drini river with 10-12m/year in the last years, in average 7.5 m/year in the north side and 4 m/year in the south side of the river delta
Space-Time Kernel Density Estimation for Real-Time Interactive Visual Analytics
We present a GPU-based implementation of the Space-Time Kernel Density Estimation (STKDE) that provides massive speed up in analyzing spatial- temporal data. In our work we are able to achieve sub- second performance for data sizes transferable over the Internet in realistic time. We have integrated this into web-based visual interactive analytics tools for analyzing spatial-temporal data. The resulting inte- grated visual analytics (VA) system permits new anal- yses of spatial-temporal data from a variety of sources. Novel, interlinked interface elements permit efficient, meaningful analyses
A Simple Framework for Multi-mode Spatial-Temporal Data Modeling
Spatial-temporal data modeling aims to mine the underlying spatial
relationships and temporal dependencies of objects in a system. However, most
existing methods focus on the modeling of spatial-temporal data in a single
mode, lacking the understanding of multiple modes. Though very few methods have
been presented to learn the multi-mode relationships recently, they are built
on complicated components with higher model complexities. In this paper, we
propose a simple framework for multi-mode spatial-temporal data modeling to
bring both effectiveness and efficiency together. Specifically, we design a
general cross-mode spatial relationships learning component to adaptively
establish connections between multiple modes and propagate information along
the learned connections. Moreover, we employ multi-layer perceptrons to capture
the temporal dependencies and channel correlations, which are conceptually and
technically succinct. Experiments on three real-world datasets show that our
model can consistently outperform the baselines with lower space and time
complexity, opening up a promising direction for modeling spatial-temporal
data. The generalizability of the cross-mode spatial relationships learning
module is also validated
Social care service provision using spatial-temporal data analytics
There is significant national interest in tackling issues surrounding the needs of vulnerable children and adults. At the same time, UK local authorities face severe financial challenges as a result of decreasing financial settlements and increasing demands from growing urban populations. With an ageing population, local authorities were reported to have spent 815 million over the nine-year period 2011/12 to 2019/20. Delivering savings of this scale, whilst protecting and safeguarding the most vulnerable citizens within a growing urban population, is one of the biggest challenges facing the local authority
Spatial-Temporal Data Mining for Ocean Science: Data, Methodologies, and Opportunities
With the increasing amount of spatial-temporal~(ST) ocean data, numerous
spatial-temporal data mining (STDM) studies have been conducted to address
various oceanic issues, e.g., climate forecasting and disaster warning.
Compared with typical ST data (e.g., traffic data), ST ocean data is more
complicated with some unique characteristics, e.g., diverse regionality and
high sparsity. These characteristics make it difficult to design and train STDM
models. Unfortunately, an overview of these studies is still missing, hindering
computer scientists to identify the research issues in ocean while discouraging
researchers in ocean science from applying advanced STDM techniques. To remedy
this situation, we provide a comprehensive survey to summarize existing STDM
studies in ocean. Concretely, we first summarize the widely-used ST ocean
datasets and identify their unique characteristics. Then, typical ST ocean data
quality enhancement techniques are discussed. Next, we classify existing STDM
studies for ocean into four types of tasks, i.e., prediction, event detection,
pattern mining, and anomaly detection, and elaborate the techniques for these
tasks. Finally, promising research opportunities are highlighted. This survey
will help scientists from the fields of both computer science and ocean science
have a better understanding of the fundamental concepts, key techniques, and
open challenges of STDM in ocean
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