12 research outputs found
Personalizable Service Discovery in Pervasive Systems
Today, telecom providers are facing changing challenges.
To stay ahead in the competition and provide market
leading offerings, carriers need to enable a global ecosystem of
third party independent application developers to deliver converged
services. This is the aim of leveraging a open standardsbased
service delivery platform. To identify and to cope with
those challenges is the main target of the EU funded project
IST DAIDALOS II. And a central point to satisfy the changing
user needs is the provision of a well working, user friendly and
personalized service discovery. This paper describes our work
in the project on a middleware in a framework for pervasive
service usage. We have designed an architecture for it, that
enables full transparency to the user, grants high compatibility
and extendability by a modular and pluggable conception and
allows for interoperability with most known service discovery
protocols. Our Multi-Protocol Service Discovery and the Four
Phases Service Filtering concept enabling personalization should
allow for the best possible results in service discovery
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A monitoring approach for runtime service discovery
Effective runtime service discovery requires identification of services based on different service characteristics such as structural, behavioural, quality, and contextual characteristics. However, current service registries guarantee services described in terms of structural and sometimes quality characteristics and, therefore, it is not always possible to assume that services in them will have all the characteristics required for effective service discovery. In this paper, we describe a monitor-based runtime service discovery framework called MoRSeD. The framework supports service discovery in both push and pull modes of query execution. The push mode of query execution is performed in parallel to the execution of a service-based system, in a proactive way. Both types of queries are specified in a query language called SerDiQueL that allows the representation of structural, behavioral, quality, and contextual conditions of services to be identified. The framework uses a monitor component to verify if behavioral and contextual conditions in the queries can be satisfied by services, based on translations of these conditions into properties represented in event calculus, and verification of the satisfiability of these properties against services. The monitor is also used to support identification that services participating in a service-based system are unavailable, and identification of changes in the behavioral and contextual characteristics of the services. A prototype implementation of the framework has been developed. The framework has been evaluated in terms of comparison of its performance when using and when not using the monitor component
Investigation of service selection algorithms for grid services
Grid computing has emerged as a global platform to support organizations for coordinated sharing of distributed data, applications, and processes. Additionally, Grid computing has also leveraged web services to define standard interfaces for Grid services adopting the service-oriented view. Consequently, there have been significant efforts to enable applications capable of tackling computationally intensive problems as services on the Grid. In order to ensure that the available services are assigned to the high volume of incoming requests efficiently, it is important to have a robust service selection algorithm. The selection algorithm should not only increase access to the distributed services, promoting operational flexibility and collaboration, but should also allow service providers to scale efficiently to meet a variety of demands while adhering to certain current Quality of Service (QoS) standards. In this research, two service selection algorithms, namely the Particle Swarm Intelligence based Service Selection Algorithm (PSI Selection Algorithm) based on the Multiple Objective Particle Swarm Optimization algorithm using Crowding Distance technique, and the Constraint Satisfaction based Selection (CSS) algorithm, are proposed. The proposed selection algorithms are designed to achieve the following goals: handling large number of incoming requests simultaneously; achieving high match scores in the case of competitive matching of similar types of incoming requests; assigning each services efficiently to all the incoming requests; providing the service requesters the flexibility to provide multiple service selection criteria based on a QoS metric; selecting the appropriate services for the incoming requests within a reasonable time. Next, the two algorithms are verified by a standard assignment problem algorithm called the Munkres algorithm. The feasibility and the accuracy of the proposed algorithms are then tested using various evaluation methods. These evaluations are based on various real world scenarios to check the accuracy of the algorithm, which is primarily based on how closely the requests are being matched to the available services based on the QoS parameters provided by the requesters
Investigation of service selection algorithms for grid services
Grid computing has emerged as a global platform to support organizations for coordinated sharing of distributed data, applications, and processes. Additionally, Grid computing has also leveraged web services to define standard interfaces for Grid services adopting the service-oriented view. Consequently, there have been significant efforts to enable applications capable of tackling computationally intensive problems as services on the Grid. In order to ensure that the available services are assigned to the high volume of incoming requests efficiently, it is important to have a robust service selection algorithm. The selection algorithm should not only increase access to the distributed services, promoting operational flexibility and collaboration, but should also allow service providers to scale efficiently to meet a variety of demands while adhering to certain current Quality of Service (QoS) standards. In this research, two service selection algorithms, namely the Particle Swarm Intelligence based Service Selection Algorithm (PSI Selection Algorithm) based on the Multiple Objective Particle Swarm Optimization algorithm using Crowding Distance technique, and the Constraint Satisfaction based Selection (CSS) algorithm, are proposed. The proposed selection algorithms are designed to achieve the following goals: handling large number of incoming requests simultaneously; achieving high match scores in the case of competitive matching of similar types of incoming requests; assigning each services efficiently to all the incoming requests; providing the service requesters the flexibility to provide multiple service selection criteria based on a QoS metric; selecting the appropriate services for the incoming requests within a reasonable time. Next, the two algorithms are verified by a standard assignment problem algorithm called the Munkres algorithm. The feasibility and the accuracy of the proposed algorithms are then tested using various evaluation methods. These evaluations are based on various real world scenarios to check the accuracy of the algorithm, which is primarily based on how closely the requests are being matched to the available services based on the QoS parameters provided by the requesters
Investigation of service selection algorithms for grid services
Grid computing has emerged as a global platform to support organizations for coordinated sharing of distributed data, applications, and processes. Additionally, Grid computing has also leveraged web services to define standard interfaces for Grid services adopting the service-oriented view. Consequently, there have been significant efforts to enable applications capable of tackling computationally intensive problems as services on the Grid. In order to ensure that the available services are assigned to the high volume of incoming requests efficiently, it is important to have a robust service selection algorithm. The selection algorithm should not only increase access to the distributed services, promoting operational flexibility and collaboration, but should also allow service providers to scale efficiently to meet a variety of demands while adhering to certain current Quality of Service (QoS) standards. In this research, two service selection algorithms, namely the Particle Swarm Intelligence based Service Selection Algorithm (PSI Selection Algorithm) based on the Multiple Objective Particle Swarm Optimization algorithm using Crowding Distance technique, and the Constraint Satisfaction based Selection (CSS) algorithm, are proposed. The proposed selection algorithms are designed to achieve the following goals: handling large number of incoming requests simultaneously; achieving high match scores in the case of competitive matching of similar types of incoming requests; assigning each services efficiently to all the incoming requests; providing the service requesters the flexibility to provide multiple service selection criteria based on a QoS metric; selecting the appropriate services for the incoming requests within a reasonable time. Next, the two algorithms are verified by a standard assignment problem algorithm called the Munkres algorithm. The feasibility and the accuracy of the proposed algorithms are then tested using various evaluation methods. These evaluations are based on various real world scenarios to check the accuracy of the algorithm, which is primarily based on how closely the requests are being matched to the available services based on the QoS parameters provided by the requesters
Hybrid approaches based on computational intelligence and semantic web for distributed situation and context awareness
2011 - 2012The research work focuses on Situation Awareness and Context Awareness topics.
Specifically, Situation Awareness involves being aware of what is happening in the vicinity
to understand how information, events, and one’s own actions will impact goals and objectives,
both immediately and in the near future. Thus, Situation Awareness is especially
important in application domains where the information flow can be quite high and poor
decisions making may lead to serious consequences.
On the other hand Context Awareness is considered a process to support user applications
to adapt interfaces, tailor the set of application-relevant data, increase the precision of
information retrieval, discover services, make the user interaction implicit, or build smart
environments.
Despite being slightly different, Situation and Context Awareness involve common
problems such as: the lack of a support for the acquisition and aggregation of dynamic environmental
information from the field (i.e. sensors, cameras, etc.); the lack of formal approaches
to knowledge representation (i.e. contexts, concepts, relations, situations, etc.)
and processing (reasoning, classification, retrieval, discovery, etc.); the lack of automated
and distributed systems, with considerable computing power, to support the reasoning on a
huge quantity of knowledge, extracted by sensor data.
So, the thesis researches new approaches for distributed Context and Situation Awareness
and proposes to apply them in order to achieve some related research objectives such
as knowledge representation, semantic reasoning, pattern recognition and information retrieval.
The research work starts from the study and analysis of state of art in terms of
techniques, technologies, tools and systems to support Context/Situation Awareness. The
main aim is to develop a new contribution in this field by integrating techniques deriving
from the fields of Semantic Web, Soft Computing and Computational Intelligence. From
an architectural point of view, several frameworks are going to be defined according to the
multi-agent paradigm.
Furthermore, some preliminary experimental results have been obtained in some application
domains such as Airport Security, Traffic Management, Smart Grids and
Healthcare.
Finally, future challenges is going to the following directions: Semantic Modeling of
Fuzzy Control, Temporal Issues, Automatically Ontology Elicitation, Extension to other
Application Domains and More Experiments. [edited by author]XI n.s
Towards Proactive Context-aware Computing and Systems
A primary goal of context-aware systems is delivering the right information at the
right place and right time to users in order to enable them to make effective decisions and improve their quality of life. There are three key requirements for achieving this goal:
determining what information is relevant, personalizing it based on the users’ context (location, preferences, behavioral history etc.), and delivering it to them in a timely manner without an explicit request from them. These requirements create a paradigm that we term as “Proactive Context-aware Computing”.
Most of the existing context-aware systems fulfill only a subset of these requirements.
Many of these systems focus only on personalization of the requested information
based on users’ current context. Moreover, they are often designed for specific domains.
In addition, most of the existing systems are reactive - the users request for some information and the system delivers it to them. These systems are not proactive i.e. they cannot anticipate users’ intent and behavior and act proactively without an explicit request from them. In order to overcome these limitations, we need to conduct a deeper analysis and enhance our understanding of context-aware systems that are generic, universal, proactive and applicable to a wide variety of domains.
To support this dissertation, we explore several directions. Clearly the most significant
sources of information about users today are smartphones. A large amount of users’ context can be acquired through them and they can be used as an effective means
to deliver information to users. In addition, social media such as Facebook, Flickr and
Foursquare provide a rich and powerful platform to mine users’ interests, preferences and behavioral history. We employ the ubiquity of smartphones and the wealth of information available from social media to address the challenge of building proactive context-aware systems. We have implemented and evaluated a few approaches, including some as part of the Rover framework, to achieve the paradigm of Proactive Context-aware Computing. Rover is a context-aware research platform which has been evolving for the last 6 years.
Since location is one of the most important context for users, we have developed
‘Locus’, an indoor localization, tracking and navigation system for multi-story buildings.
Other important dimensions of users’ context include the activities that they are engaged
in. To this end, we have developed ‘SenseMe’, a system that leverages the smartphone and its multiple sensors in order to perform multidimensional context and activity recognition for users. As part of the ‘SenseMe’ project, we also conducted an exploratory study of privacy, trust, risks and other concerns of users with smart phone based personal sensing systems and applications.
To determine what information would be relevant to users’ situations, we have developed ‘TellMe’ - a system that employs a new, flexible and scalable approach based on Natural Language Processing techniques to perform bootstrapped discovery and ranking of relevant information in context-aware systems. In order to personalize the relevant information, we have also developed an algorithm and system for mining a broad range of users’ preferences from their social network profiles and activities. For recommending new information to the users based on their past behavior and context history (such as visited locations, activities and time), we have developed a recommender system and approach for performing multi-dimensional collaborative recommendations using tensor factorization.
For timely delivery of personalized and relevant information, it is essential to anticipate
and predict users’ behavior. To this end, we have developed a unified infrastructure,
within the Rover framework, and implemented several novel approaches and algorithms
that employ various contextual features and state of the art machine learning techniques
for building diverse behavioral models of users. Examples of generated models include
classifying users’ semantic places and mobility states, predicting their availability for accepting calls on smartphones and inferring their device charging behavior. Finally, to
enable proactivity in context-aware systems, we have also developed a planning framework based on HTN planning. Together, these works provide a major push in the direction of proactive context-aware computing