Sürdürülebilir Yeşil Kampüs Koleksiyonu / Sustainable Green Campus Collection

Permanent URI for this collectionhttps://hdl.handle.net/11147/7755

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Department: search.filters.department.İzmir Institute of Technology. Computer EngineeringScopus Q: search.filters.scopusQuartile.N/A

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Now showing 1 - 7 of 7
  • Article
    Citation - WoS: 10
    Citation - Scopus: 26
    Mobile Join Operators for Restricted Sources
    (Hindawi Publishing Corporation, 2005) Özakar, Belgin; Morvan, Franck; Hameurlain, Abdelkader
    We consider the problem of query execution when there is limited access to the relations, i.e. when binding patterns require values to be specified in order to get data from the relation. This problem is common in virtual data integration systems where there are heterogeneous sources with various restricted access patterns and query capabilities. Another problem is the lack of the statistical information about the sources and occurrence of unpredictable events. We introduce two mobile join operators, MDJoin and SMDJoin which are designed for restricted sources and implemented using ‘mobile agents’ in order to benefit from their autonomous and reactive characteristics. Mobile operators of restricted sources are capable to deal with restricted sources and react to the variations between the compile-time estimations and run-time computations of data during query execution. The difference between the two new query operators lies in their level of adaptation ability to the execution environment. Performance results show that mobile agent-based approach at operator level can lead to a significant reduction in response time with restricted sources.
  • Conference Object
    Citation - Scopus: 1
    Policies for Role Based Agents in Environments With Changing Ontologies
    (International Foundation for Autonomous Agents and Multiagent Systems, 2011) Tekbacak, Fatih; Tuğlular, Tuğkan; Dikenelli, Oğuz
    Software agents try to achieve the goals of roles that they have in an environment. It is supposed that the dynamic structure of role based agents can be connected with updatable domain ontologies of the environment. Ontology evolution can cause the update of agent behaviors or access restrictions to ontological elements. So regulation for the agent behaviors may be needed. Our motivation is to create a suitable policy model for agents, environments and organizations when ontologies in the environment can change.
  • Conference Object
    Citation - Scopus: 2
    Resource Allocation Algorithm for a Relational Join Operator in Grid Systems
    (Association for Computing Machinery (ACM), 2012) Çokuslu, Deniz; Hameurlain, Abdelkader; Erciyeş, Kayhan; Morvan, Franck
    Grid systems become very popular during the last decade because of their rapidly increasing computational capabilities. On the other hand, the advances on different domains cause enormous increase in the scale of the manipulated data. This issue augments the importance of distributed query processing and causes researchers to port their underlying environment onto the grid systems. However the dynamicity, heterogeneity and large scale characteristics of grid systems pose new problems for the distributed query processing domain. Resource allocation for query processing in grid systems is one of these problems, which attracts many researchers' attention. In this paper, we propose a new resource allocation algorithm for one relational join operator in a query considering characteristics of the grid systems. We provide theoretical analyses of the proposed algorithm and we consolidate analyses with the simulations. Copyright © 2012 ACM.
  • Conference Object
    Developing Applications On-Board of Robots With Becerik
    (Trans Tech Publications, 2012) Kumova, Bora İsmail; Takan, Savaş
    Robot applications are mostly first developed on a computer and thereafter loaded onto the robot. However, in many situations, developing applications directly on the robot may be more effective. For instance, children who have not learned using a computer yet and who develop their robot applications while playing. Or for instance in the robots' operating environment, where there is no computer available. In this contribution we present the properties of the software tool becerik, for developing applications on-board a robot and for running them in multi-tasking mode concurrently. Furthermore, we introduce the programming language of the applications that has the same name becerik, which consists of only 6 commands. © (2012) Trans Tech Publications, Switzerland.
  • Conference Object
    Citation - WoS: 2
    Citation - Scopus: 12
    A Review of Cloud Deployment Models for E-Learning Systems
    (Institute of Electrical and Electronics Engineers Inc., 2013) Leloğlu, Engin; Ayav, Tolga; Aslan, Burak Galip
    With the significant growth in the cloud-based systems, many industries give their attention to cloud computing solutions. E-learning is a promising application area since its typical requirements such as dynamically allocation of computation and storage resources, coincide well with cloud characteristics. This paper presents some possible cloud solutions in e-learning environments by emphasizing its pros and cons. It is of paramount importance to choose the most suitable cloud model for an e-learning application or an educational organization in terms of scalability, portability and security. We distinguish various deployment alternatives of cloud computing and discuss their benefits against typical e-learning requirements.
  • Conference Object
    Citation - WoS: 7
    Citation - Scopus: 12
    Time Synchronization Algorithms Based on Timing-Sync Protocol in Wireless Sensor Networks
    (Institute of Electrical and Electronics Engineers Inc., 2008) Kulaklı, Ali Burak; Erciyeş, Kayhan
    Wireless Sensor Networks(WSN) are large scale networks of sensors running on wireless environment. For an application running on a WSN, gathered data by the sensors are time critical in most of the cases. However, almost all the nodes suffer from a problem named clock drift. This problem causes clock difference among nodes as time goes because the processors do not run exactly at the same speed. There are many proposed solutions to remedy this problem. TPSN (Timing-sync Protocol for Sensor Networks) is one of the effective protocols proposed to synchronize sensor networks. In this paper, we propose enhancements over TPSN to synchronize nodes in a wireless sensor network more effectively with a lower message complexity and higher precision.
  • Conference Object
    Citation - WoS: 4
    Citation - Scopus: 6
    Robust Placement of Mobile Relational Operators for Large Scale Distributed Query Optimization
    (Institute of Electrical and Electronics Engineers Inc., 2007) Ergenç, Belgin; Morvan, Franck; Hameurlain, Abdelkader
    This paper presents a compile-time placement method of mobile relational operators MROs in a large scale environment. MROs are self adaptive to changing runtime conditions by deciding their execution place if they discover compile-time estimation errors. Proposed placement methods tend to have a main drawback with MROs running over a large scale environment: their focus is on finding optimal performance depending on single-point estimation at compile-time, instead of optimal performance over an estimation interval. We propose: (i) to determine the migration space of a MRO including the sites on which the MRO is allowed to migrate during its execution, and (ii) to find the robust site which will allow acceptable response time in an estimation interval. Performance study shows that, with a risk of loosing around 6% in response time, it is possible to gain up to 300% with the proposed robust placement.