633 research outputs found
Measuring and improving community resilience: a Fuzzy Logic approach
Due to the increasing frequency of natural and man-made disasters worldwide,
the scientific community has paid considerable attention to the concept of
resilience engineering in recent years. Authorities and decision-makers, on the
other hand, have been focusing their efforts to develop strategies that can
help increase community resilience to different types of extreme events. Since
it is often impossible to prevent every risk, the focus is on adapting and
managing risks in ways that minimize impacts to communities (e.g., humans and
other systems). Several resilience strategies have been proposed in the
literature to reduce disaster risk and improve community resilience. Generally,
resilience assessment is challenging due to uncertainty and unavailability of
data necessary for the estimation process. This paper proposes a Fuzzy Logic
method for quantifying community resilience. The methodology is based on the
PEOPLES framework, an indicator-based hierarchical framework that defines all
aspects of the community. A fuzzy-based approach is implemented to quantify the
PEOPLES indicators using descriptive knowledge instead of hard data, accounting
also for the uncertainties involved in the analysis. To demonstrate the
applicability of the methodology, data regarding the functionality of the city
San Francisco before and after the Loma Prieta earthquake are used to obtain a
resilience index of the Physical Infrastructure dimension of the PEOPLES
framework. The results show that the methodology can provide good estimates of
community resilience despite the uncertainty of the indicators. Hence, it
serves as a decision-support tool to help decision-makers and stakeholders
assess and improve the resilience of their communities
High Dimensional Data Clustering using Self-Organized Map
As the population grows and e economic development, houses could be one of basic needs of every family. Therefore, housing investment has promising value in the future. This research implements the Self-Organized Map (SOM) algorithm to cluster house data for providing several house groups based on the various features. K-means is used as the baseline of the proposed approach. SOM has higher silhouette coefficient (0.4367) compared to its comparison (0.236). Thus, this method outperforms k-means in terms of visualizing high-dimensional data cluster. It is also better in the cluster formation and regulating the data distribution
AN INVESTIGATION INTO AN EXPERT SYSTEM FOR TELECOMMUNICATION NETWORK DESIGN
Many telephone companies, especially in Eastern-Europe and the 'third world', are
developing new telephone networks. In such situations the network design engineer needs
computer based tools that not only supplement his own knowledge but also help him to cope
with situations where not all the information necessary for the design is available. Often
traditional network design tools are somewhat removed from the practical world for which
they were developed. They often ignore the significant uncertain and statistical nature of the
input data. They use data taken from a fixed point in time to solve a time variable problem,
and the cost formulae tend to be on an average per line or port rather than the specific case.
Indeed, data is often not available or just plainly unreliable. The engineer has to rely on
rules of thumb honed over many years of experience in designing networks and be able to
cope with missing data.
The complexity of telecommunication networks and the rarity of specialists in this area often
makes the network design process very difficult for a company. It is therefore an important
area for the application of expert systems. Designs resulting from the use of expert systems
will have a measure of uncertainty in their solution and adequate account must be made of
the risk involved in implementing its design recommendations.
The thesis reviews the status of expert systems as used for telecommunication network
design. It further shows that such an expert system needs to reduce a large network problem
into its component parts, use different modules to solve them and then combine these results
to create a total solution. It shows how the various sub-division problems are integrated to
solve the general network design problem. This thesis further presents details of such an
expert system and the databases necessary for network design: three new algorithms are
invented for traffic analysis, node locations and network design and these produce results
that have close correlation with designs taken from BT Consultancy archives.
It was initially supposed that an efficient combination of existing techniques for dealing with uncertainty
within expert systems would suffice for the basis of the new system. It soon
became apparent, however, that to allow for the differing attributes of facts, rules and data
and the varying degrees of importance or rank within each area, a new and radically different
method would be needed.
Having investigated the existing uncertainty problem it is believed that a new more rational
method has been found. The work has involved the invention of the 'Uncertainty Window'
technique and its testing on various aspects of network design, including demand forecast,
network dimensioning, node and link system sizing, etc. using a selection of networks that
have been designed by BT Consultancy staff. From the results of the analysis, modifications
to the technique have been incorporated with the aim of optimising the heuristics and
procedures, so that the structure gives an accurate solution as early as possible.
The essence of the process is one of associating the uncertainty windows with their relevant
rules, data and facts, which results in providing the network designer with an insight into the
uncertainties that have helped produce the overall system design: it indicates which sources
of uncertainty and which assumptions are were critical for further investigation to improve
upon the confidence of the overall design. The windowing technique works by virtue of its
ability to retain the composition of the uncertainty and its associated values, assumption, etc.
and allows for better solutions to be attained.BRITISH TELECOMMUNICATIONS PL
(VANET IR-CAS): Utilizing IR Techniques in Building Context Aware Systems for VANET
Most of the available context aware dissemination systems for the Vehicular Ad hoc Network (VANET) are centralized systems with low level of user privacy and preciseness. In addition, the absence of common assessment models deprives researchers from having fair evaluation of their proposed systems and unbiased comparison with other systems. Due to the importance of the commercial, safety and convenience services, three IR-CAS systems are developed to improve three applications of these services: the safety Automatic Crash Notification (ACN), the convenience Congested Road Notification (CRN) and the commercial Service Announcement (SA). The proposed systems are context aware systems that utilize the information retrieval (IR) techniques in the context aware information dissemination. The dispatched information is improved by deploying the vector space model for estimating the relevance or severity by calculating the Manhattan distance between the current situation context and the severest context vectors.
The IR-CAS systems outperform current systems that use machine learning, fuzzy logic and binary models in decentralization, effectiveness by binary and non-binary measures, exploitation of vehicle processing power, dissemination of informative notifications with certainty degrees and partial rather than binary or graded notifications that are insensitive to differences in severity within grades, and protection of privacy which achieves user satisfaction. In addition, the visual-manual and speech-visual dual-mode user interface is designed to improve user safety by minimizing distraction. An evaluation model containing ACN and CRN test collections, with around 500,000 North American test cases each, is created to enable fair effectiveness comparisons among VANET context aware systems. Hence, the novelty of VANET IR-CAS systems is: First, providing scalable abstract context model with IR based processing that raises the notification relevance and precision. Second, increasing decentralization, user privacy, and safety with the least distracting user interface. Third, designing unbiased performance evaluation as a ground for distinguishing significantly effective VANET context aware systems
Pattern Recognition
A wealth of advanced pattern recognition algorithms are emerging from the interdiscipline between technologies of effective visual features and the human-brain cognition process. Effective visual features are made possible through the rapid developments in appropriate sensor equipments, novel filter designs, and viable information processing architectures. While the understanding of human-brain cognition process broadens the way in which the computer can perform pattern recognition tasks. The present book is intended to collect representative researches around the globe focusing on low-level vision, filter design, features and image descriptors, data mining and analysis, and biologically inspired algorithms. The 27 chapters coved in this book disclose recent advances and new ideas in promoting the techniques, technology and applications of pattern recognition
Proceedings of the GIS Research UK 18th Annual Conference GISRUK 2010
This volume holds the papers from the 18th annual GIS Research UK (GISRUK). This year the conference, hosted at University College London (UCL), from Wednesday 14 to Friday 16 April 2010. The conference covered the areas of core geographic information science research as well as applications domains such as crime and health and technological developments in LBS and the geoweb.
UCL’s research mission as a global university is based around a series of Grand Challenges that affect us all, and these were accommodated in GISRUK 2010.
The overarching theme this year was “Global Challenges”, with specific focus on the following themes:
* Crime and Place
* Environmental Change
* Intelligent Transport
* Public Health and Epidemiology
* Simulation and Modelling
* London as a global city
* The geoweb and neo-geography
* Open GIS and Volunteered Geographic Information
* Human-Computer Interaction and GIS
Traditionally, GISRUK has provided a platform for early career researchers as well as those with a significant track record of achievement in the area. As such, the conference provides a welcome blend of innovative thinking and mature reflection. GISRUK is the premier academic GIS conference in the UK and we are keen to maintain its outstanding record of achievement in developing GIS in the UK and beyond
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