Frank Siegemund

Wirelessly accessible sensor populations (WASP) for elderly care monitoring

This paper presents an application of a service-based architecture to pervasive monitoring of the elderly using ambient and wearable sensors. The design consideration of the model addresses heterogeneous computing and network resource utilization, allowing inter-operability and supporting dynamic environments to achieve system wide resource optimization. An application of this architecture is presented for assessing the activities of daily living, which is the basis for pervasive sensing for elderly care.

The WASP Architecture for Wireless Sensor Networks

This paper presents some intermediate results of the EU-IST project WASP that aims to develop an integrated model for implementing applications using wireless sensor networks. In this paper we present our approach to programming sensor networks. The main contribution concerns the separation of three abstraction levels leaving more room for standardization than with current practices. In addition, we propose to program the network from an overall perspective rather than programming individual nodes. For doing this we present two programming models that complement one another. The proposed programming model is event-based, corresponding closely to the nature of wireless sensors. The paper shows our approaches by giving several examples and ends with a description of wireless sensor networks related services and gives an outlook on future work.

WASP – Wirelessly Accessible Sensor Populations: A Project Overview

This article presents an overview of the integrated project WASP that deals with the research and development of Wirelessly Accessible Sensor Populations. WASP is a European project of the Embedded Systems Strategic Objective in Framework Programme 6 of the European Union. WASP is covering the complete technology chain from sensor node hardware to the implementation of applications. The article illustrates the integrated approach of WASP by subsuming the variety of research and development issues that are addressed to reach the ambitious project goal: the provision of a complete system view for building large populations of collaborating objects.

Towards pervasive connectivity in mobile computing settings

Pervasive computing scenarios often assume pervasive connectivity. Yet, because of different communication technologies that are integrated into different devices (e.g., IrDA or Bluetooth), because of different high-level communication protocols (e.g., IPv4 vs. IPv6), and because of security and networking constraints (e.g., firewalls and NATs) pervasive connectivity is an illusion in most real-world environments. This is especially true for scenarios involving mobile users because there is no prior knowledge about the devices and users present. This paper presents a novel approach for dealing with these connectivity restrictions in environments where groups of people need to cooperate with each other in an ad-hoc fashion. The core idea is to establish an overlay among group members that is used to share information about the current network environment. This information is conveyed in the form of dynamically generated tag sequences that are displayed and captured by the digital cameras integrated into an increasing number of mobile devices. Users who want to invite others to a group invoke an application that displays multiple, dynamically generated tags on their mobile devices screen. People, who want to join the group, then point the camera integrated into their handheld devices to the other devices screen. Thus, the displayed tag sequence is captured and decoded in real time; and the information contained therein can be used to securely and robustly join the group. By transmitting information about the group, group participants, and communication parameters within a sequence of tags, it is possible to provide ad-hoc connectivity in various mobile computing settings.

Using Digital Cameras for Text Input on Mobile Devices

This paper presents novel text input methods for mobile devices. In particular, it shows how users can capture text from books, newspapers, and other objects by using the digital cameras that are integrated into an increasing number of smartphones. The idea is to select text from a live video stream generated by these digital cameras. Different interaction patterns are discussed that allow users to select text: (1) automatic detection of the word closest to a fixed position on the mobile devices screen, (2) delayed movement of the text selection to improve the precision of the selection procedure, and (3) using the stylus to select words and word groups. The proposed interaction patterns are evaluated based on the results of a user study, and their application is shown in an example scenario. The presented research has practical relevance because it can improve the usability of mobile applications such as online searching

An operator placement algorithm for complex in-network processing

In sensor network applications that do complex innetwork processing, each node may perform its own task rather than all nodes executing the same aggregation function. To support the development of such applications, this paper introduces a network-level programming model that is based on the data flow in the application. When deploying the application, such a high-level model has to be mapped to nodes in the specific network topology. This paper presents an operator placement algorithm that tries to find an optimal mapping that minimizes data transmission throughout the network.

Senslets - Applets for the Sensor Internet

This paper presents new approaches for dynamically integrating sensors into a surrounding computing infrastructure. Our work is based on small programs - called Senslets - that are stored on sensor nodes. Senslets are written using a programming model based on a high-level programming language such as C# or Java, but they do not assume a virtual execution environment on the sensors. Instead, they are downloaded to a mobile device or stationary computer, where they are hosted and executed. In this paper, we present (1) a programming framework for developing Senslets, (2) the tools necessary for deploying Senslets on resource-constrained sensor nodes, and (3) a hosting environment for executing Senslets on mobile phones. The paper also contains an evaluation and a description of example applications.

Porting the .NET Compact Framework to Symbian Phones

A method of manufacturing a multiple mirror reflector for land based telescopes. At least one series of identical segments are mounted on a rigid support to form a large primary reflector with each segment forming a part of the total profile. Each segment includes an accurately profiled reflective metal layer bonded to a concave surface of a substrate by an adhesive layer. The layer is formed on the appropriate substrate surface by transfer replication.