325 research outputs found
Developing an automatic brachial artery segmentation and bloodstream analysis tool using possibilistic C-means clustering from color doppler ultrasound images
Automatic segmentation of brachial artery and blood-flow dynamics are important for early detection of cardiovascular disease and other vascular endothelial malfunctions. In this paper, we propose a software that is noise tolerant and fully automatic in segmentation of brachial artery from color Doppler ultrasound images. Possibilistic C-Means clustering algorithm is applied to make the automatic segmentation. We use HSV color model to enhance the contrast of bloodstream area in the input image. Our software also provides index of hemoglobin distribution with respect to the blood flow velocity for pathologists to proceed further analysis. In experiment, the proposed method successfully extracts the target area in 59 out of 60 cases (98.3%) with field expert’s verification
A framework for the development and maintenance of adaptive, dynamic, context-aware information services
This paper presents an agent-based methodological approach to design distributed service-oriented systems which can adapt their behaviour according to changes in the environment and in the user needs, even taking the initiative to make suggestions and proactive choices. The highly dynamic, regulated, complex nature of the distributed, interconnected services is tackled through a methodological framework composed of three interconnected levels. The framework relies on coordination and organisational techniques, as well as on semantically annotated Web services to design, deploy and maintain a distributed system, using both a top-down and bottom-up approach. We present results based on a real use case: interactive community displays with tourist information and services, dynamically personalised according to user context and preferences.Preprin
Hyperspectral Unmixing Overview: Geometrical, Statistical, and Sparse Regression-Based Approaches
Imaging spectrometers measure electromagnetic energy scattered in their
instantaneous field view in hundreds or thousands of spectral channels with
higher spectral resolution than multispectral cameras. Imaging spectrometers
are therefore often referred to as hyperspectral cameras (HSCs). Higher
spectral resolution enables material identification via spectroscopic analysis,
which facilitates countless applications that require identifying materials in
scenarios unsuitable for classical spectroscopic analysis. Due to low spatial
resolution of HSCs, microscopic material mixing, and multiple scattering,
spectra measured by HSCs are mixtures of spectra of materials in a scene. Thus,
accurate estimation requires unmixing. Pixels are assumed to be mixtures of a
few materials, called endmembers. Unmixing involves estimating all or some of:
the number of endmembers, their spectral signatures, and their abundances at
each pixel. Unmixing is a challenging, ill-posed inverse problem because of
model inaccuracies, observation noise, environmental conditions, endmember
variability, and data set size. Researchers have devised and investigated many
models searching for robust, stable, tractable, and accurate unmixing
algorithms. This paper presents an overview of unmixing methods from the time
of Keshava and Mustard's unmixing tutorial [1] to the present. Mixing models
are first discussed. Signal-subspace, geometrical, statistical, sparsity-based,
and spatial-contextual unmixing algorithms are described. Mathematical problems
and potential solutions are described. Algorithm characteristics are
illustrated experimentally.Comment: This work has been accepted for publication in IEEE Journal of
Selected Topics in Applied Earth Observations and Remote Sensin
Online Shopping Decisions Enhancement with Fuzzy Expert System
Purpose Nowadays, due to the rapid development of the Internet and the rapid growth of web pages, many electronic websites are using product recommendation systems to guide users to the products that they need. Such systems usually provide a list of suggested items that the user may prefer. These systems are provided as a support tool to help users obtain information that best meets their needs. These systems can actually improve user decisions, resulting in increased sales and mutual customer satisfaction. The purpose of the paper is to improve user decisions in online shopping using fuzzy expert system.
Methodology: The statistical population of this study consists of 30 experts in the field of e-commerce who were selected by combining two methods of deliberate sampling and snowball sampling. To analyze the status of improvement of users' decisions, a fuzzy expert system was created using input variables business reputation status, environmental factors status in e-commerce, online store features; product specifications; user/customer characteristics.
Findings: The final results showed that there is no significant difference between the results of the created expert system and the mean of expert opinions.
Originality/Value: In this paper, a conceptual Model to improve user decisions in online shopping using a fuzzy expert system is designed
Towards an Organizational Strategic Vitality Theory: A Study of a Public Sector Board of Directors
Boards of directors govern practically all organizations of significant size in the public and private sector. Improving the understanding of how boards function is critical because when boards fail, the results can be devastating. Little is understood about the functioning of boards of directors in the public sector, which accounts for a significant amount of the gross national product of the world\u27s economy. The author observed a public sector board of directors for one year. Using the grounded theory research method to analyze the observations, he generated a theory of organizational strategic vitality that describes how a board of directors that is motivated to sustain its organization\u27s strategic vitality will undertake actions to increase the board\u27s effectiveness; strengthen relationships with customers, stakeholders, and partners; create an effective strategy; infuse the strategy throughout its organization; and evaluate and foster strategic performance. In addition, this study found that this public sector board\u27s motivation was self-determined, that motivation affected the selection of the board\u27s primary role, and that the other major roles of a board can become subservient to the primary role once chosen. In addition to these findings, organizational classism was identified as a major impediment to strategic implementation
Human-assisted self-supervised labeling of large data sets
There is a severe demand for, and shortage of, large accurately labeled datasets to train supervised computational intelligence (CI) algorithms in domains like unmanned aerial systems (UAS) and autonomous vehicles. This has hindered our ability to develop and deploy various computer vision algorithms in/across environments and niche domains for tasks like detection, localization, and tracking. Herein, I propose a new human-in-the-loop (HITL) based growing neural gas (GNG) algorithm to minimize human intervention during labeling large UAS data collections over a shared geospatial area. Specifically, I address human driven events like new class identification and mistake correction. I also address algorithm-centric operations like new pattern discovery and self-supervised labeling. Pattern discovery and identification through self-supervised labeling is made possible through open set recognition (OSR). Herein, I propose a classifier with the ability to say "I don't know" to identify outliers in the data and bootstrap deep learning (DL) models, specifically convolutional neural networks (CNNs), with the ability to classify on N+1 classes. The effectiveness of the algorithms are demonstrated using simulated realistic ray-traced low altitude UAS data from the Unreal Engine. The results show that it is possible to increase speed and reduce mental fatigue over hand labeling large image datasets.Includes bibliographical references
Representing archaeological uncertainty in cultural informatics
This thesis sets out to explore, describe, quantify, and visualise uncertainty in a
cultural informatics context, with a focus on archaeological reconstructions. For quite
some time, archaeologists and heritage experts have been criticising the often toorealistic
appearance of three-dimensional reconstructions. They have been highlighting
one of the unique features of archaeology: the information we have on our heritage
will always be incomplete. This incompleteness should be reflected in digitised
reconstructions of the past.
This criticism is the driving force behind this thesis. The research examines archaeological
theory and inferential process and provides insight into computer visualisation.
It describes how these two areas, of archaeology and computer graphics,
have formed a useful, but often tumultuous, relationship through the years.
By examining the uncertainty background of disciplines such as GIS, medicine,
and law, the thesis postulates that archaeological visualisation, in order to mature,
must move towards archaeological knowledge visualisation. Three sequential areas
are proposed through this thesis for the initial exploration of archaeological uncertainty:
identification, quantification and modelling. The main contributions of the
thesis lie in those three areas.
Firstly, through the innovative design, distribution, and analysis of a questionnaire,
the thesis identifies the importance of uncertainty in archaeological interpretation
and discovers potential preferences among different evidence types.
Secondly, the thesis uniquely analyses and evaluates, in relation to archaeological
uncertainty, three different belief quantification models. The varying ways that these
mathematical models work, are also evaluated through simulated experiments. Comparison
of results indicates significant convergence between the models.
Thirdly, a novel approach to archaeological uncertainty and evidence conflict visualisation
is presented, influenced by information visualisation schemes. Lastly, suggestions
for future semantic extensions to this research are presented through the
design and development of new plugins to a search engine
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