Processing Location Dependent Continuous Queries in Distributed Mobile Databases using Mobile Agents

The growth in the number of mobile users is motivating the new technology of mobile computing to offer many new types of services like location-based services that pose many challenging problems for location-dependent query processing and data management. In this paper, we discuss the various challenges in distributed processing of location-dependent continuous queries in a mobile environment by studying the different scenarios in which both the querying unit and the object being queried are in motion. Then we proceed to classify different types of location dependent queries. We discuss the different solutions to solve these complex location dependent queries using caching techniques that facilitate fast access to data and at the same time minimize the massive network traffic generated due to location dependent query processing in a wireless environment. To further reduce the data transfer the query results are cached so that these results are reusable. The conventional query processing method like join processing of data from mobile units and server is directly applied in the mobile environment. Additionally this paper also focuses on the methods of location-dependent query processing and applications. The main goal of this paper is to study the various location dependent query processing methods along with data management problems involved in evaluation of Location-dependent queries and classify them.

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 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.

The technology of mobile agents, where software pieces of active control and storage (called mobile agents) travel the network and perform tasks distributively, is of growing interest as an Internet technology. Similarly, smartcard holders can be considered mobile users as they access the network at various points. Such mobile processing can be employed in large scale census applications in statistics gathering, in surveys and tallying, in reading and collecting local control information, etc. This distributed computing paradigm where local pieces of data are getting accumulated in a mobile unit presents new information security challenges. Here, we point at some problems it poses and suggest solutions. The basic problem considered involves the design of a mobile agent that is capable of traversing an untrusted (curious) network while gathering and securing data from the nodes that it visits. We assume that some subset of the nodes may collaborate to track the agent, and we assume that snapshots of memory are taken at each node at times that are unpredictable to the agent. The data that is gathered must be securely stored within the agent and the adversarial nodes must remain oblivious to what is taken by the agent. In addition, the agent’s movement throughout the network should be made difficult to trace. Furthermore, we assume that the agent is limited in storage capacity. To prevent the nodes from getting decryption capability, the agent must carry a public key for (asymmetric) encryption. We present an economical solution that we call “sliding encryption≓. This is a new mode of operation of public key cryptosystems that allows the encryption of small amounts of plaintext yielding small amounts of ciphertext. Furthermore, the encryption is performed so that it is intractable to recover the plaintext without the appropriate private key. We also describe how to modify sliding encryption so that the resulting ciphertexts are hard to correlate, thus making it possible to have mobile agents that are not easy to trace. Sliding encryption is applicable to mobile agent technology and may have independent applications to “storage-limited technology≓ such as smartcards and mobile units.

Mobile agents can provide many benefits to the development of distributed applications. But the mobile agent system will face some security threat since it will run in an opening network environment. In this paper, we analyzed the security threats in mobile agent system and provided a method to build the trusted connect between entities in mobile agent environment. This method uses the trusted platform module in trusted computing platform as the trusted base. When a mobile agent wants to migrate to another platform, it should use a trusted connect between the source host and the goal host. The agent and agent platform can trust with each other. This method will be helpful to build a trusted computing environment for the mobile agent system.

Efficient continuous query processing is critical for many applications, including monitoring remote sensors network traffic management, and online transaction processing. To overcome resource limitations and achieve real-time responsiveness, continuous query systems research focuses on issues such as punctuation-driven operator-state purging [4], load shedding, operator scheduling [7] and plan optimization and on-line migration [9]. However, when real-time yet accurate results are critical such as in stock market analysis, then there is a limitation to what any of the above optimization techniques can accomplish. Hence, distributed processing must be applied to support required scalability. It has been already proven in traditional database systems [3] that distributed processing results in high scale-up and speed-up capabilities due to aggregated resources. The design of a distributed continuous query system is characterized by an extra complexity, considered in the design of our D-Cape engine. In such a system, data streams may be infinite and initial cost statistics about the data streams are typically unknown. Moreover, cost statistics continue to change over time. Our research on distributed stream processing addresses two critical questions: (1) How to initially distribute query plans given little or possibly no cost information, and (2) How to efficiently adapt the query distribution corresponding to runtime environmental changes. Even though research is now under way in designing distributed continuous query systems [2], [1], results to date, as far as we know, are based on simulations. Our work offers empirical results of distributed continuous query processing using an actual software system [5], [6]. D-Cape, a distributed continuous query processing architecture, employs stream query engines over a cluster of shared-nothing processors. We employ a dedicated distribution manager to manage

In this paper, we address the fidelity of information collected from distributed, interactive, pervasive computing environments. Queries in these dynamic networks come in two forms: snapshot queries and continuous queries. The former executes through the network and returns values that satisfy the query criteria at a particular instant in time. The latter expects a result that is updated over time to reflect changes in the system. The fidelity, or quality, of the results of these queries can be significantly impacted by the unpredictability of the dynamic network; as the query is distributed and executed, changes that occur due to network and environmental dynamics can cause the query to miss potential results or to report inconsistent information. Our previous work has shown how we can provide semantically meaningful statements about the fidelity, or quality, of the result of a snapshot query in a dynamic networked environment. In this paper, we demonstrate how this fidelity can also be used to adapt a continuous query's processing to make its execution best match the conditions in the underlying dynamic environment.

The postal service is considered one of the important elements of the national economic, social and political infrastructure of the Republic of Uzbekistan, as in all countries, as an integral part of the national economy, in addition to the development of a unified information system and its support, as well as serving the development of important segments of the national economy, are recognized as appropriate. During the years of independence, fundamental changes have taken place in the postal system of Uzbekistan. Over the past period, several resolutions and Decrees of the President of the Republic of Uzbekistan, and the Cabinet of Ministers of the Republic of Uzbekistan have been adopted to develop the industry. The material and technical base of the regional and district communication departments of the open joint-stock company "Uzbekistan pochtasi" has been strengthened. It covered the development of production and the introduction of quality innovations in the types of services. The provision of such a convenient and high-quality service to the residents of our country is carried out not only by communication departments in regional centers but also through regional and district communication departments. All this is logically consistent with the ongoing socio-economic reforms in the country and is successfully integrated into the processes of the global sphere of information services. Along with this, practically in all post offices of the republic, new types of services were organized and an increase in the number of new jobs was achieved. A system has been established to provide quality services to the population of our country. Postal exchange is carried out not only within our republic but also with neighboring and foreign countries. Neither the Internet nor email can replace the postal service. On the contrary, they created new opportunities for postal services. We live in an era when different means of communication complement each other. The post office provides the necessary services not only to Internet buyers and sellers but also to those who do not know how to use new technologies and do not have the necessary importance in their lives to communicate with the outside world. This article also provides that the postal service plays an important role in developing and strengthening our country's economy, improving citizens' lives, and increasing domestic comfort.

As in most European countries, the mental health of immigrants in France has recently been the subject of scientific scrutiny. Since the end of World War II voluntary special mental health services for migrants and refugees have been created in France and especially in Paris, but none has been based on epidemiological data. Generally, this lack of objective data gave rise to the assumption that many immigrants might not be getting the type of services they required. The birth of a new type of service (e.g. for migrants, refugees, ethnic groups, trauma and torture victims) was a political reaction to what was, at the time, expressed as an essential unmet need regarding this very specific population. In this article we review, from an anthropological point of view, the different paradigms that have prevailed over the last 50 years.

The security problem of mobile agent is important for applications using mobile agent technology. In this paper, we analyzed the security problems of mobile agent system exposed in opening environment and proposed a method to improve the authentication and credentials management in mobile agent environment. In our design, the trusted computing platform is used as the basic platform to running mobile agent systems, and the trusted platform module will used to help the authentication and credentials management. We also gave a model system for building trusted mobile agent system. In this system, the security of mobile agent is improved by using trusted computing platform which is linked with upper layer applications through the trusted software stack. Then, trusted services for mobile agent, including authentication, credential management and key storage, are supported.

Ubiquitous computing and The Internet-of-Things (IoT) grow rapidly in today's life and evolving to Self-organizing systems (SoS). A unified and scalable information processing and communication methodology is required. In this work, mobile agents are used to merge the IoT with Mobile and Cloud environments seamless. A portable and scalable Agent Processing Platform (APP) provides an enabling technology that is central for the deployment of Multi-Agent Systems (MAS) in strong heterogeneous networks including the Internet. A large-scale use-case deploying Multi-agent systems in a distributed heterogeneous seismic sensor and geodetic network is used to demonstrate the suitability of the MAS and platform approach. The MAS is used for earthquake monitoring based on a new incremental distributed learning algorithm applied to seismic station data, which can be extended by ubiquitous sensing devices like smart phones. Different (mobile) agents perform sensor sensing, aggregation, local learning and prediction, global voting and decision making, and the application.

Mobile agents are a competitive concept of client-server computing and are especially suitable in mobile environments, that are characterized by low bandwidth communication facilities and ad hoc connection/disconnection to stationary systems. They can be used for information retrieval and information filtering, in which case they evaluate replies and return only the relevant data. Mobile agents as a metaphor of active objects are created on a mobile device such as a Personal Digital Assistant (PDA), will be launched into the information galaxy and are fulfilling the mobile user ‘s task on the services available on networked stationary systems. One transmission channel for these itinerant agents is email. This paper introduces Active M 3 as an example of an active mail framework, which can be regarded as a first approach in authoring mobile agents in a graphical interactive manner. Active M 3 integrates two known concepts: active mail and multimedia mail.The idea of active or computational mail has existed since 1976 (3); transfer programs embedded in standard mail which automatically execute at the receivers site. This hiker —the active mail message— can also carry multimedia elements (audio, animation, image etc, and indeed sub-agents) in his backpack, which it can also render and orchestrate at the receivers site in a sophisticated manner. Therefore, synchronization concepts are introduced. To summarize, the objective of Active M 3 is the development and implementation of a system for the realization of active multimedia mail and a composing tool as an easy to use interactive authoring environment. An extension towards a more generalized authoring environment for this remote programming concept enables authoring of mobile agents.This paper introduces the basic ideas. The results of the proposed concept for a composer for active multimedia mail are presented through a realized prototype.KeywordsActive MailComputational MailMultimedia MailMIMERemote ProgrammingMo-bile AgentsItinerant AgentsSynchronization

Monitoring and tracking LBS applications require data-base and application support to model and manage moving objects in both database and application domains. Such services must also provide efficient processing of continuous queries over moving objects. In contrast to regular queries that are evaluated only once, a continuous query remains active over a period of time.

This study proposed the system for collecting the learning contents using the mobile agent in e-learning and m-learning. The mobile agent in wireless environment can provide the flexible works through a network and collect the adequate learning contents according to the learner?s request. Moreover, the mobile agent can reduce the communication expenses. In this study, we proposed the CAS system that the mobile agent intellectually collected the appropriate learning contents in wireless learning. We used the SCORM-based contents as learning materials. In order to examine the validity of proposed study, we designed and implemented proposed system with mobile agent.

Interests in skyline query processing have significantly increased since it can be used in many applications, such as multi-criteria decision making, data mining, and user preference queries. In this paper, we propose continuous skyline queries over dynamic data set. Since the dynamic data set constantly changes as time passes, continuous skyline queries processing over dynamic data set becomes ever more complicated compared with static data set. We propose a multiple layer grids scheme for efficiently processing continuous skyline queries over skewed data set. The proposed scheme divides the work space into multiple layer grids and creates the skyline influence regions of each layer grid based on the existing data set. The continuous skyline queries are handled only when the dynamic data points update within the skyline influence regions of each layer grid. Since the multiple layer grids are divided dynamically, it is feasible even for the highly skewed data set. Experiments based on various synthetic data sets and real data sets show that our proposed scheme outperforms the existing schemes.