The use of a PDA with ad-hoc built-in information retrieval functionalities can help people in visiting an historical site in a natural manner instead of traditional audio/visual pre-recorded guides. The aim of this work is to build a versatile virtual-guide system adaptable to the user needs of mobility and therefore usable on different devices (e.g. PDAs, Smartphones). An information retrieval service is included and is easily accessible through a spoken language interaction. The system takes the advantages of chat-bot and speech recognition technologies, allowing a natural interaction with the user. The system has been implemented on a Qtek PDA with Windows Mobile 2003 with the aim of assisting an user during a visit to a cultural heritage institution.
Simultaneous operation of multiple network interfaces can benefit mobile devices with diverse network interfaces. This paper outlines an IP-level network activation strategy that aims at optimum use of the complementary features of the underlying networks. A key design issue in such strategies is the energy cost of different network interfaces. As a step towards validating and fine-tuning our strategy, we devised an experimental setting to measure the relative energy consumption of WiFi and GPRS interfaces in two modern mobile devices. The paper reports the experimental method and results. Our study indicates that the proposed strategy –in this case, reaching devices from the GPRS interface and, whenever appropriate, handing over some sessions to the WiFi interface– is plausible from energy consumption viewpoint and in some cases it outperforms the existing methods. The energy consumption model obtained will be used to make the network activation strategy energy aware. Key words—Mobile devices, multiple network interfaces, connectivity management, energy cost, WiFi-GPRS.
In this paper, we present a policy-based architecture to be used in identifying the location of users within a pervasive system environment. Mobile users can define their own policies governing the granularity of their location identification. Such granularity is governed by a combination of policy predicates and premise topology information. Privacy can vary in a spectrum of levels from total obstruction to total transparency of location information. Sensors and agents coupled with such sensors continuously forward user locations and policies to a policy and state repository. The policy and state repository can be queried for user location information. Location information is filtered to comply with user defined policies at the agents closest to the source of the query. Historical information is eventually archived at the policy repository, and can also be used to query for possible predictions of futuristic location of users.
To overcome shortcomings of Exact Matching Method (EMM) and Substitute Description Method (SDM), an Inexact Matching Method Based on Ontology and Semantic Distance (OSDIMM) is introduced. This method, firstly, describes resources information with Ontology languages to get Resource Ontology Description (RODs); then, infers Concept Hierarchy Trees and Property Hierarchy Trees from RODs; lastly, computes semantic distance between a required resource and each of existing resources based on Hierarchy Trees, and selects resources by semantic distances and thresholds. The results of experiments indicate: firstly, OSDIMM is averagely 3.8889 times as large as EMM at the aspect of matching count when the threshold of holistic semantic distance is zero and inputs are same, i.e., OSDIMM can utilize fully resources discovered than EMM; then, OSDIMM can adapt more smartly than SDM to the condition of lots of resources and properties being in pervasive computing environment; at last, it can differentiate the weightiness between entities and properties, and can describe the degree of resources satisfying query with property tuple suitability degree.
Polymers are melt spun by extruding threadlines of filaments from a spinneret; quenching the filaments through a quench zone; reducing the tension on the threadlines of filaments to a value substantially equal to the tension at the hereinafter-mentioned winding point, by converging each threadline of filaments to form a strand while applying a lubricant; and winding each strand on a spool at a take-up speed of at least about 1800 meters per minute, and without further reducing the tension by means, such as godets. Apparatus for carrying out the method is described. The convergence means may be adjustable to change the position thereof relative to the bottom of the quench zone.
Mobile users need lightweight devices with low energy consumption. When applications are executed on remote servers instead of locally on the end-user’s device, the weight of the device can be reduced and battery lifetime can be extended. Therefore, thin-clients are ideally suited for mobile users. All calculation logic is removed from the device and the communication with the application server is accomplished by a remote desktop protocol. Reactions to user events can appear on the screen only after a two-way path delay, so application responsiveness can decrease if the user moves further away from his server. To enable ubiquitous thin-client computing with satisfying user responsiveness, the application should make a parallel movement with the mobile user. This paper focusses on the handover between two application servers. A model is presented for the design of a thin-client network that meets the requirements of moving users and the resulting number of handovers is shown. Three mechanisms for the server handover are presented. For each scenario, an estimation is made for the timeframe during which the client does not receive
In the coming years user-centric services will be deployed in our homes, cars, offices, etc. Users expect that these services are autonomous and user-friendly. This requires that these services can adapt themselves to changes in the environment, implying that they have to become contextaware. In this paper we present a formal context model and an OSGi based framework that allows easy development and installation of context-aware services. The platform is open since it allows that new components are easily plugged in. Applicability is illustrated with a location determination use case in an desk sharing office environment where employees don’t have a fixed location or desk.
In the ambient computing future, security promises to be the foundational design feature that allows pervasive systems to protect personal information privacy. As fledgling pervasive computing systems gain a foothold presence in becoming more flexible and, at the same time, more invisibly interconnected, system users may have to trade privacy and protection to gain full entry into this new information-laden environment. This paper examines the current state-of-the-shelf security components, which predominantly overlay wired and wireless networks that will support next generation pervasive systems with a defense-in-depth approach. Information technology “best practices” are considered, and privacy concerns within typical networks are discussed. An examination of emerging privacy protecting technologies is presented, and Radio Frequency Identification (RFID) tags and legal concerns are discussed to portray the asymmetry of information flow in pervasive systems that can impact our personal information privacy.
In this paper, we present a general ad hoc network and the session secret conception. By using session secret, key cache and reuse without using timestamp is possible. A combination of protocols is presented, which is suitable for general ad hoc network and any two participants who communicate with each other very often.
This paper uses and extends the ideas of a multi-device interface design approach from a previous work developing a framework for mobile access to web systems. It can adapt any desktop designed web system interface to common mobile devices, such as pocket PCs and smartphones. The final interface preserves the original conceptual model to avoid ambiguities on the user’s mental model while using several interfaces for the same application alternatively. As a result, it also provides less maintenance cost and complexity for the interfaces generated automatically from the desktop version. We plan to evaluate a prototype for this framework sooner to check if the theory’s assumption concerning a better usability over common linear transformations may be perceived.
⎯ Due to many resource constraints of wireless sensor networks and characteristics of sensor data stream, some of the data management techniques that work well for traditional database are insufficient for managing and processing sensor network data. In this paper we present a cluster based query protocol for wireless sensor networks which uses self-organized sensor clusters to register queries, process queries and disseminate data within the sensor network. This protocol can provide an integrated solution to address some of the challenge problems of wireless sensor networks, including locating sensors, energy efficient data query processing, and fault tolerant network operations.
For applications of embedded systems, several processors are scheduled on a processor because very limited applications are used. Recently application areas are broadened and used to be like personal computers. Operating systems are considered one of critical factors to develop embedded systems. Linux is becoming one of popular operating systems for embedded applications, because of open sources and royalty free. Since Linux is designed for general purpose applications, it is not suitable for embedded multimedia systems. For multimedia applications, it is required that the scheduler operate without jitters or jams. This paper presents a method to schedule many processes by guaranteeing quality of services for video and audio. This goal is achieved through the mixed scheduling using critical based EDF and round robin method to utilize the CPU time. Simulation results show that the proposed algorithm decreases the number of violations and schedules many processors effectively for multimedia embedded applications.
- Security is a big challenge when wireless sensor networks are deployed in a hostile environment. Due to the computational and storage overheads, traditional asymmetric-key based security protocols are not suitable for the resource-constrained wireless sensors. Several symmetric-key distribution protocols have been proposed in literature to establish shared cryptographic keys between sensor nodes, but most of them only work for small-scale networks due to their linearly increased communication overhead and key storage overhead. Furthermore, existing protocols are not secure when the number of compromised nodes exceeds a threshold value. In this paper, we propose a new distributed pairwise key establishment method for large-scale wireless sensor networks. Compared with existing key distribution protocols, our scheme guarantees any two sensors to establish a pairwise key between them with low overheads. A high level network security also can be achieved in our scheme even a large number of sensors are compromised.
Real-time speaker verification, with speech acquired using the NIST Mk-III microphone array and an autodirective beamforming algorithm, is demonstrated. The software and hardware backbone of the demonstration is the NIST Smart Flow System and Mk-III Array, both developed by National Institute of Standards and Technology in support of multimodal research communities. A microphone array acquires speech signals; a steered response beamformer calculates the direction of arrival (DoA) of the dominant signal; and a speaker verification component determines whether the signal is speech from a specific privileged speaker. If so, a camera will slew to the DoA of the privileged speaker; but not other speakers, or other kinds of sound. Novel approaches were taken to the design of the basic components to obtain good realtime demonstration performance.
Quality control is crucial to the success of any business and organization. Due to the ever-increasing complexity and mission-critical nature of quality control, development, deployment, and management of information systems for quality control overwhelms the capabilities of software developers and system administrators. This has motivated our research, co-sponsored by IBM and HP, to explore development of multi-agent autonomic architecture for quality control systems. We have designed a new multi-agent autonomic architecture for quality control systems. This paper presents the new multi-agent autonomic architecture, and discusses our latest research results and our plans for enhancement of this research project. Background information is also provided in this paper.
Over the last decade, there is an increasing trend in the use of more and more mobile navigation devices. In order to make mobile navigation more intelligent, issues such as location and context awareness need to be addressed to offer location-based navigation services. For example, one might think of a scenario of a large commercial center where a customer with some mobile device in hand wishes to go to a drugstore. The system should efficiently identify the current location of the customer, a list of drugstores located nearby, the easiest path to the next drugstore and provide routing and destination suggestions to the customer. In this paper, assuming that the mobile device gives us the co-ordinates of the current location of the customer, we present a graph and an octree-based approach to identify the location of the customer, identify a list of destinations located in the neighborhood and determine the best possible destination and the respective path to the destination.
Home Automation Technologies make possible the deployment of home monitoring and control applications. These technologies rely on different networking technologies. Some of them are oriented towards some basic functionalities like switching a device on, off and dimming for lights. Others tend to provide more advanced functionalities like reading of the actual temperature from a thermometer. In this paper, we group them in two categories: low level home automation protocols and high level home automation protocols. We then introduce a universal domotics integrator architecture for a unified home automation system based on the UPnP technology. This architecture could be extended to a large-scale Internet automation groundwork for globally interconnected devices. In this way, inter-device communications and automation procedures could be established via networking automation protocols in conjunction with web automation services. Finally, we study the feasibility, extendibility and inter-operability features of our proposed integrated architecture.
