2,012 research outputs found

    Window Query Processing with Proxy Cache

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    A location dependent query (LDQ) result set is valid only in a specific region called the validity region (VR). While limiting the validity of a particular result set to a given area, the VR may also be used in caching implementations to determine if cached results satisfy semantically equivalent queries. Existing LDQ caching schemes rely on the database servers to provide the VR at a cost of high computational overhead. Alternatively, a LDQ proxy cache, which approximates the VR can be employed, freeing the database servers from the high cost of calculating the VR. A LDQ proxy cache architecture is proposed to compute an estimated validity region (EVR) based on the observed querying history at the proxy server. We present an algorithm - Window_EVR - for the LDQ proxy to compute the EVR for a window query result set. The simulation results show that LDQ proxy caching using the Window_EVR algorithm significantly reduces both the window query response time and the workload at the database servers while maintaining query result set accuracy

    A survey of machine learning techniques applied to self organizing cellular networks

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    In this paper, a survey of the literature of the past fifteen years involving Machine Learning (ML) algorithms applied to self organizing cellular networks is performed. In order for future networks to overcome the current limitations and address the issues of current cellular systems, it is clear that more intelligence needs to be deployed, so that a fully autonomous and flexible network can be enabled. This paper focuses on the learning perspective of Self Organizing Networks (SON) solutions and provides, not only an overview of the most common ML techniques encountered in cellular networks, but also manages to classify each paper in terms of its learning solution, while also giving some examples. The authors also classify each paper in terms of its self-organizing use-case and discuss how each proposed solution performed. In addition, a comparison between the most commonly found ML algorithms in terms of certain SON metrics is performed and general guidelines on when to choose each ML algorithm for each SON function are proposed. Lastly, this work also provides future research directions and new paradigms that the use of more robust and intelligent algorithms, together with data gathered by operators, can bring to the cellular networks domain and fully enable the concept of SON in the near future

    CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines

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    Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective. The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines. From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research

    Mobile web resource tracking during a disaster or crisis situation

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    This paper proposes a prototype solution for a mobile web resource tracking system using mobile devices during an emergency situation. The system provides real time data to a decision maker so that he/she can effectively and efficiently monitor resources and assess the situation accordingly. Mobile devices (i.e., smart phones) support the ease of use for any location and at anytime. The Internet technology is selected to enable multiple or cross platform technology solutions for different mobile devices. Resources in the scope of this project are human resources (e.g., a doctor, a police officer) and a chemical list in a room. With the use of a GPS-enabled device or a wireless-enabled device, the system is used to provide the current location of the human resources. Transferring data between system databases and mobile devices is one of the important areas to address in this project. Since location data of a user is sensitive data, data should be protected via an encrypted protected network. In addition, because of the urgency of any crisis situation, it is critical that data from the system be able to be retrieved in a reasonable time frame. The investigation includes the exploration of database and data transfer solutions to meet the data availability during emergency conditions on mobile devices. This document includes a description of the system design, a review of current technologies, proposed methodology, and the implementation. Review of the literature section provides background information on current available technologies that were studied (section 3). Four identified factors are suggested in the system design – usability, security, availability, and performance. The discussion of which technology is selected for each feature can be found in the implementation section 4. Proposed future research areas can be found in the conclusion section and recommendations for future work section

    Concept and Implementation of a Mobile Interactive Floor Plan

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    The relocation of a company facility always comes with great strategic and organizational challenges. The new site needs to be found, employees need to relocate to the new location, the workplaces need to be assigned to the employees, conference rooms need to be added to the conference room reservation system and the staff needs to be introduced to the new building. This process can cause high financial costs as well as a reduced employee performance during the time of acclimatization. To minimize the additional stress created through these changes, a lot of effort needs to be put in informing the employees about news concerning the relocation. Guided tours through the building need to be organized, regular appearing newsletters need to be created and events to integrate new hires into the company culture need to be held. New technologies and the wide coverage of mobile devices provide a great opportunity to support the employees and can offer a modern and intuitive assistance both during the time of adjustment and every day work. This thesis covers the development of an interactive floor plan, designed to help the employees find a certain person or conference room in the building. It discusses the challenges during the design and development and gives an overview of the future development goals of the project
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