Location Dependent Query Processing – Issues, Challenges and Applications

With the increase in the number of mobile users, the need for new type of services and applications is also on the rise. Particularly, a growing area of interest is to provide location dependent services to the mobile users. In this paper, we present a system that supports distributed processing of location-dependent continuous queries on distributed mobile data in a mobile environment using mobile agents. We investigate a scenario in which both the querying unit and the object being queried (target object) are capable of movement and the mobile unit is equipped with more powerful capabilities, including the storage of a small database and the capacity of data processing. Since our system deals with continuous queries, we propose a shared incremental update mechanism, which caches the results of the previously evaluated queries and avoids redundant results thereby minimizing the data traffic in wireless environment. To further reduce the data transfer we share the cached data among different queries. Our system uses mobile agents for evaluating queries, which involves data from both the server and mobile unit, and it helps in parallel processing of data and it, can efficiently track the mobile units involved in the system. The conventional query processing method like join processing of data from mobile units and server is directly applied in the mobile environment.

A variety of research exists for the processing of continuous queries in large, mobile environments. Each method tries, in its own way, to address the computational bottleneck of constantly processing so many queries. In this paper, we introduce an efficient and scalable system for monitoring continuous queries by leveraging the parallel processing capability of the Graphics Processing Unit. We examine a naive CPU-based solution for continuous range-monitoring queries, and we then extend this system using the GPU. Additionally, with mobile communication devices becoming commodity, location-based services will become ubiquitous. To cope with the very high intensity of location-based queries, we propose a view oriented approach of the location database, thereby reducing computation costs by exploiting computation sharing amongst queries requiring the same view. Our studies show that by exploiting the parallel processing power of the GPU, we are able to significantly scale the number of mobile objects, while maintaining an acceptable level of performance.

The continuous development of wireless networks and mobile devices has motivated an intense research in mobile data services. Some of these services provide the user with context-aware information. Specifically, location-based services and location-dependent queries have attracted a lot of interest. In this article, the existing literature in the field of location-dependent query processing is reviewed. The technological context (mobile computing) and support middleware (such as moving object databases and data stream technology) are described, location-based services and location-dependent queries are defined and classified, and different query processing approaches are reviewed and compared.

Location-based services (LBSs) provide information based on location information specified in a query. Queries that support LBSs are called location- dependent queries (LDQ). In this paper, the issues involved with organizing location dependent data and answering LDQ queries on the air are investigated. An efficient data organization, called Jump Rdnn-tree, and the corresponding search algorithms are proposed. The performance of the proposed Jump Rdnn-tree and other traditional indexes (enhanced for wireless broadcasting) is evaluated using both uniform and skew data. The results show that Jump Rdnn-tree substantially outperforms the traditional indexes.

Location Based Services can be considered as one of the most rapidly expanding fields of the mobile communications sector, with an impressively large application range. The proliferation of mobile/wireless Internet and mobile computing, and the constantly increasing use of handheld, mobile devices and position tracking technologies prepared the grounds for the introduction of this new type of services. The combination of position fixing mechanisms with location‐dependent, geographical information, can offer truly customized personal communication services through the mobile phone or other type of devices. Prompted by the avalanche of technology advances in the aforementioned areas in this paper we present an integrated platform for delivering Location Based Services (LBS). The platform covers the full life cycle of a LBS starting from the specification of the service, covering issues like the deployment and maintenance of services, the service invocation and the final delivery of the produced results to the invoking user. A prototype implementation of the discussed platform was developed and used to perform a series of trial services, with the purpose of demonstrating the pursued functionality.

IoT networks allow various new types of services, such as Location-Based Services (LBS), requiring an end-to-end Quality of Service (QoS) without any interruption. However, sustaining these networks is difficult when the devices can move and vanish at any time, as they can be carried around, might run out of battery, or be turned off by users. In this paper, we propose a new programmable multitier architecture and a continuity of service protocol named ConSerN, which are based on the Software Defined Network (SDN) approach and Connected Dominating Sets (CDS) techniques. Unlike the existing solutions, the proposed mechanism considers a dynamic topology where nodes are not static from a mobility and topology point of view. Furthermore, as most of the applications using LBS need to consider the geographic position of the connected objects, we have added it in the selection process of the dynamic gateways. The performance evaluation was conducted using experimentation and emulation tools allowing scenario generations. We used three main metrics i.e. the quality of link, the number of dominant nodes and the amount of control messages. The obtained results show that the proposed solution benefits from a high number of gateways to achieve great performance in terms of overhead and quality of link.

Query processing is that method or technique in area of mobile atmosphere which deal using mobile environment. This research in that way user can think advancement using query processing and it takes more use for speedily accessing global query processing and it is joint venture of query processing between dissimilar sites includes fixed server movable computer. The necessity saving of energy and also the existence of lopsided features in a moveable computing atmosphere, the predictable query processing for a scattered database cannot be straightly genuine to a moveable computing organization. The mobile environment is a collection of mobile diverse hosts, which are enabled to communicate using wireless links. These wireless links are change giving to the natures of mobile networks. Moreover, nodes in the ad-hoc network have to link without any centralized or help. The usability for the user also changes using query processing tool. Thus, this mechanism that allows the sharing of functionality among different devices in same environment change the way of user communication for searching fast query time in mobile computing environment. The aim of this research is to make innovation in query optimization technique in mobile computing environment. This research focuses on improvement of various query optimization techniques for highly effective and trustworthy query optimization methods.

The networked ICT technologies (such as the Internet) are having a dramatic effect on how services and especially knowledge services are innovated, designed, produced and distributed. In addition ICT-networks such as the Internet have created the basis for the development of new types of services. E-services are defined here as services that are produced, provided and/or consumed through the use of ICT-networks such as for example Internet-based systems and mobile solutions. E-services can be used by both consumers and businesses, and can be accessed via a wide range of information appliances (Hoffman, 2003, p.53). E-services include also selling of physical goods on the Internet as for example an airline ticket that is purchased online, but delivered by surface mail to the buyers or government services offered on the Internet or e-government. There are three main characteristics of e-services: • The service is accessible across the Internet or other electronic networks • The service is consumed by a person across the Internet or other electronic networks • There might be a fee that the consumer pays the provider for using the e-service, but that might not always be the case as for example in some e-services offered by the government. Normally the production, provision or consumption of a service requires the interaction between the service provider and the user of the service. Traditionally this has been based on personal interactions, most often face-to-face interactions. In e-services, the production, consumption and/or provision of services takes place through the intermediation of an ICT-network such as Internet-based systems or mobile solutions. Examples of e-services are e-banking, e-library services, e-publishing, airline tickets, e-government, information and location services. The advent of e-commerce and e-services has raised a number of challenges for knowledge intensive service organizations such as consulting companies, libraries and publishers, as well as for companies selling physical goods. The purpose of this study is to investigate the challenges that e-services are posing and will pose for research or academic libraries. The study has focused on the issues that Roskilde University Library (RUB) has had to deal with as a result of e-services adoption as well as the future challenges that e-services provide for RUB. The study is based on a number of interviews with RUB management, other secondary material provided by Roskilde University library and information provided on the Web page.

The development of web 2.0 technologies since the mid-1990s has given a powerful new impetus to the growing trend of customers participating in the creation of services. Not only has it enabled this participation on a larger scale, it has also stimulated the development of a new type of service — one that integrates customers in the service creation process in ways never seen before. Customer service is now provided not by service providers alone but also by customers. Large numbers of customers are working for customers in a collaborative effort or, to be more precise, in large-scale collective action.KeywordsCollective ActionUser CommunityShared GoalOpen Source ProjectTravel BusinessThese keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

Service trading in mobile environments

With the increasing in demand on location-based aware services and RFIDs, efficient processing of continuous queries over moving object streams becomes important. In this paper, we propose an efficient in-memory processing of continuous queries on themoving object streams.We model moving objects using function of time and use it in the prediction of usefulness of objects with respect to the continuous queries. To effectively utilize the limited memory, we derive several replacement policies to discard objects that are of no potential interest to the queries and design efficient algorithms with light data structures. Experimental studies are conducted and the results show that our proposed method is both memory and query efficient.

In recent years, large amount of data modeled by graphs, namely graph data, have been collected in various domains. Efficiently processing queries on graph databases has attracted a lot of research attentions. Supergraph query is a kind of new and important queries in practice. A supergraph query, q, on a graph database D is to retrieve all graphs in D such that q is a supergraph of them. Because the number of graphs in databases is large and subgraph isomorphism testing is NP-complete, efficiently processing such queries is a big challenge. This paper first proposes an optimal compact method for organizing graph databases. Common subgraphs of the graphs in a database are stored only once in the compact organization of the database, in order to reduce the overall cost of subgraph isomorphism testings from stored graphs to queries during query processing. Then, an exact algorithm and an approximate algorithm for generating significant feature set with optimal order are proposed to construct indices on graph databases. The optimal order on the feature set is to reduce the number of subgraph isomorphism testings during query processing. Based on the compact organization of graph databases, a novel algorithm of testing subgraph isomorphisms from multiple graphs to one graph is presented. Finally, based on all these techniques, a query processing method is proposed. Analytical and experimental results show that the proposed algorithms outper-form the existing similar algorithms by one to two orders of magnitude.

An approach to process continuous location-dependent queries on moving objects with support for location granules

Individuals with serious mental illness often are unable to access consumer- and family-oriented community care, resulting in repeated hospitalizations, incarceration, and homelessness. The "medical home" concept was developed in primary care to provide accessible and accountable services for individuals with chronic medical conditions. Building on the work done in primary care, the authors propose a "mental health home." The model of care incorporates medical home characteristics, such as access to and coordination of services, integration of primary and preventive care, adoption of recovery orientation and evidence-based practices, and family and community outreach. Barriers to and strategies for implementation of mental health homes are discussed.

A New Kind of Homelessness for Individuals With Serious Mental Illness? The Need for a "Mental Health Home"