Catálogo de publicaciones - libros

With the rapid development of technologies related to Ubiquitous Sensor Network (USN), sensors are being utilized in various application areas. In general, a sensor has a low computing capacity and power and keeps sending data to the central server. In this environment, uncertain data can be stored in the central server due to delayed transmission or other reasons and make query processing produce wrong results. Thus, this paper examines how to process uncertain data in ubiquitous sensor networks and suggests an efficient index, called UR-tree, for uncertain data. The index reduces the cost of update by delaying update in uncertainty areas. In addition, it solves the problem of low accuracy in search resulting from update delay by delaying update only for specific update areas. Lastly, we analyze the performance of UR-tree and prove the superiority of its performance by comparing its performance with that of R-Tree and PTI using various datasets.

With the development of theory and technology of Web Service, Web Service Composition (WSC) has become the core Service-Oriented Computing technology. It is important for business process to select the best component services with multi-dimensional QoS assurances to construct a complex one. But there exist some problems, such as evaluation for QoS properties of a service is not full-scale and the criteria is not clear, the weight for each QoS metric doesn’t consider both subjective sensations and objective facts. In this paper we propose a WSC model to provide multi-dimensional QoS supports in service selection and replacement. We consider SLA and recovery mechanism for the service failure during its execution. A utility function is defined as the evaluation standard, which aggregates all QoS metrics after normalizing their values. Then we use Subjective-Objective Weight Mode (SOWM) to set the weight of each QoS metric. Finally we introduce our prototype and evaluations, test the availability of the decision mode and the results prove it is predominant compared with other decision modes.

In this paper we describe the execution model supported by , a middleware built on top of Globus for execution of Java applications on the grid. This execution model allows a user to launch Java applications that will run on a grid from her machine without requiring this machine to be part of the grid (e.g. a gLite ). Additionally, it allows grid users to regard file systems, i.e. file systems accessible from their local workstations, as part of the set of file systems accessible within the grid. This eliminates the necessity of performing previous uploads of classes and data files, which helps to meet the grid goal of achieving seamless access to distributed resources. We describe how to implement the services offered by this execution model on Globus-based grids. We compare the use of this execution model with the standard mechanisms for submission of Java jobs in /gLite, a flavor of Globus Toolkit 2. We present experiments showing that this execution model can improve performance for running Java applications on Globus-based grids.

With the increasingly complexity of ubiquitous computing environment, large and distributed embedded software are used more and more widely. After a design model has been completed, assigning components in the design model while meeting multiple runtime constraints is a critical problem in model-based large distributed embedded software development. In this paper, we propose a new method of component assignment. This method uses backtracking algorithm to search the assignment space, and a balance distance function to decide the feasible assignment scheme. Unlike other methods that view computation, communication, and memory resources as independent resources, this method analyzes their holistic influence on component assignment with the goal of keeping the balance between computation resource consumption and memory resource consumption, and the balance of execution density among different processors. Experimental evaluation shows the component assignment method has high success ratios, low time overheads, and good scalability.

In recent large scale deployment of active RFID systems has been introduced by many applications, but a variety of critical issues remain unresolved. Especially, the impact of collision is the most essential problem. In this paper, we propose a Learning-based Dynamic Framed Slotted ALOHA algorithm (LDFSA) which mitigates collision from the active RFID tags and complies with international standard, ISO/IEC 18000-7. In addition, this paper includes the performance evaluations of the proposed LDFSA algorithm with the conventional algorithms. According to the result, the proposed LDFSA algorithm shows better performance than other conventional algorithms.

The concept of Object-based Storage Devices (OSD), which is standardized by the ANSI T10 technical committee, is an emerging storage paradigm that replaces storages of traditional fixed-size block abstraction with those of variable-size objects that virtualizes the underlying physical storage. In this paper, we describe our substantial implementation of the OSD security framework in OASIS, which is an OSD system developed at ETRI (Electronics and Telecommunications Research Institute) in Korea. We also describe our credential caching subsystem, called Lcache, which is implemented in the client side of our OSD security framework in order to improve the performance of issuing credentials.

This paper presents a framework of simulation environment (SEMU) which allows developers to understand the behavior of applications or protocols for a wireless sensor network (WSN) before deploying real nodes in a physical environment. For eliminating the gap between simulation and real deployment, SEMU has supported fast real code emulation by dynamic binary translation technique. SEMU also models the controlled environment as virtual operating system (Virtual OS) to coordinate the interactions of large number of nodes. In addition, we have proposed a co-simulation model to enhance the accuracy of pure software simulation. Then a further synchronization problem will be addressed and resolved by the co-simulation model. The evaluation results show SEMU is really a fast scalable WSN simulator with real code emulation.

Recently, the () project has been unveiled. Its goal is to provide an environment which facilitates adaptive control of distributed applications written in Java for the Grid or the Desktop Grid. However, in its current state it can be used only in closed environments (e.g. within a single laboratory), as it lacks features that would make it ready for an “open Grid.” The aim of this paper is to show how the can be augmented by usage of software agents and ontologies to make it more robust.

Service-Oriented Architecture (SOA) development paradigm has emerged to improve the critical issues of creating, modifying and extending solutions for business processes integration incorporating process automation and automated exchange of information between organizations. Web services technology follows the SOA’s principles for developing and deploying applications. Besides, Web services are considered as the platform for SOA, for both intra- and inter-enterprise communication. However, an SOA does not incorporate information about occurring events into business processes that are the main features of supply chain management. These events and information delivery are addressed in an Event-Driven Architecture (EDA). Having this into account, we propose a Web service-based system named BPIMS-WS that offers a brokering service for the procurement of products in supply chain management scenarios. As salient contributions, our system provides a hybrid architecture combining features both SOA and EDA and a set of mechanisms for business processes pattern management, monitoring based on UML sequence diagrams, Web services-based management, event publish/subscription and reliable messaging service.

Recent growth in computing devices from the smartphone to the desktop computer has led to users interacting with multiple computing devices throughout the course of the day. Modern computing sessions are a graphically rich, multi-tasking experience, representing a considerable amount of state. There is seldom the ability to automatically move a session from one device to another; instead users must manually restore applications to their previous state. Without session mobility, the problems of unsynchronised information and communication barriers become apparent. We present a thin client approach to supporting session mobility across a broad range of devices. We use an adaptive approach, thereby supporting a fine granularity of devices. Furthermore, our approach enables rich diverse sessions composed of applications specific to a range of platforms, reducing constraints imposed by mobile devices, and boosting productivity by allowing access to a wider range of applications from a single device.