Forschungsinstitut für Anwendungsorientierte Wissensverarbeitung

This paper describes results from evaluating different self-localization approaches in indoor environments for mobile robots. The algorithms examined are based on 2D laser scans and an odometry position estimate and do not need any modifications in the environment. An important requirement for the self-localization is the ability to cope with office-like environments as well as with environments without orthogonal and rectilinear walls. Furthermore, the approaches have to be robust enough to cope with slight modifications in the daily environment and should be fast enough to be used online on board of the robot system. To fulfil these requirements we made some extensions to the existing approaches and combined them in a suitable manner. Real world experiments with our robot within the everyday environment of our institute show that the position error can be kept small enough to perform navigation tasks.

(1996). Electronic commerce: Building blocks of new business opportunity. Journal of Organizational Computing and Electronic Commerce: Vol. 6, Electronic Commerce, pp. 1-10.

Describes the robotic wheelchair MAid (Mobility Aid for Elderly and Disabled People). MAid's task is to support and transport people with limited motion skills. It is based on a commercial wheelchair that has been equipped with an intelligent control and navigation system. Conversations with disabled and elderly people and with their physicians indicate that the automatic functions desired in a robotic wheelchair do not include following walls or passing doorways, but do include navigation in narrow, cluttered environments and through wide, crowded areas. MAid performs these functions.

Spatial joins are join operations that involve spatial data types and operators. Due to basic properties of spatial data, many conventional join strategies suffer serious performance penalties or are not applicable at all. The join strategies known from conventional databases that can be applied to spatial joins and the ways in which some of these techniques can be modified to be more efficient in the context of spatial data are discussed. A class of tree structures, called generalization trees, that can be applied efficiently to compute spatial joins in a hierarchical manner are described. The performances of the most promising strategies are analytically modeled and compared.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Simulations are used in very different contexts and for very different purposes. An emerging development is the possibility of using simulations to obtain a more or less representative reproduction of organs or even entire persons. Such simulations are framed and discussed using the term 'digital twin'. This paper unpacks and scrutinises the current use of such digital twins in medicine and the ideas embedded in this practice. First, the paper maps the different types of digital twins. A special focus is put on the concrete challenges inherent in the interactions between persons and their digital twin. Second, the paper addresses the questions of how far a digital twin can represent a person and what the consequences of this may be. Against the background of these two analytical steps, the paper defines first conditions for digital twins to take on an ethically justifiable form of representation.

In this paper we focus on the task of tracking multiple moving objects in rapidly changing, dynamic environments. Objects are extracted from laser range finder images and correspondences between successive images are established by network optimization techniques. The approach is implemented on a robotic wheelchair, used in two applications and evaluated experimentally.

Cognitive impairments are one of the main contributors to disability and poor long-term outcome in schizophrenia. Proof-of-concept trials indicate that repetitive transcranial magnetic stimulation (rTMS) applied to the left dorsolateral prefrontal cortex (DLPFC) has the potential to improve cognitive functioning. We analyzed the effects of 10-Hz rTMS to the left DLPFC on cognitive deficits in schizophrenia in a large-scale and multicenter, sham-controlled study. A total of 156 schizophrenia patients with predominant negative symptoms were randomly assigned to a 3-week intervention (10-Hz rTMS, 15 sessions, 1000 stimuli per session) with either active or sham rTMS. The Rey Auditory Verbal Learning Test, Trail Making Test A and B, Wisconsin Card Sorting Test, Digit Span Test, and the Regensburg Word Fluency Test were administered before intervention and at day 21, 45, and 105 follow-up. From the test results, a neuropsychological composite score was computed. Both groups showed no differences in any of the outcome variables before and after intervention. Both groups improved markedly over time, but effect sizes indicate a numeric, but nonsignificant superiority of active rTMS in certain cognitive tests. Active 10-Hz rTMS applied to the left DLPFC for 3 weeks was not superior to sham rTMS in the improvement of various cognitive domains in schizophrenia patients with predominant negative symptoms. This is in contrast to previous preliminary proof-of-concept trials, but highlights the need for more multicenter randomized controlled trials in the field of noninvasive brain stimulation.

article Free Access Share on Research issues in spatial databases Authors: O. Guenther FAW Ulm, Postfach 2060, D7900 Ulm, Germany FAW Ulm, Postfach 2060, D7900 Ulm, GermanyView Profile , A. Buchmann GTE Laboratories, Incorporated, 40 Sylvan Road, Waltham, MA GTE Laboratories, Incorporated, 40 Sylvan Road, Waltham, MAView Profile Authors Info & Claims ACM SIGMOD RecordVolume 19Issue 4Dec. 1990 pp 61–68https://doi.org/10.1145/122058.122065Online:01 December 1990Publication History 67citation988DownloadsMetricsTotal Citations67Total Downloads988Last 12 Months26Last 6 weeks10 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

Abstract Motivation: Primer design involves various parameters such as string-based alignment scores, melting temperature, primer length and GC content. This entails a design approach from multicriteria decision making. Values of some of the criteria are easy to compute while others require intense calculations. Results: The reference point method was found to be tractable for trading-off between deviations from ideal values of all the criteria. Some criteria computations are based on dynamic programs with value iteration whose run time can be bounded by a low-degree polynomial. For designing standard PCR primers, the scheme offers in a relative gain in computing speed of up to \batchmode \documentclass[fleqn,10pt,legalpaper]{article} \usepackage{amssymb} \usepackage{amsfonts} \usepackage{amsmath} \pagestyle{empty} \begin{document} \(50\ :\ 1\) \end{document}over ad-hoc computational methods. Single PCR primer pairs have been used as model systems in order to simplify the quantization of the computational acceleration factors. The program has been structured so as to facilitate the analysis of large numbers of primer pairs with minor modifications. The scheme significantly increases primer design throughput which in turn facilitates the use of oligonucleotides in a wide range of applications including: multiplex PCR and other nucleic acid-based amplification systems, as well as in zip code targeting, oligonucleotide microarrays and nucleic acid-based nanoengineering. Availability: A public version of the software DOPRIMER is accessible under http://doprimer.interactiva.de Contact: kaempke@faw.uni-ulm.de

This paper describes the hardware design, control, and navigation system of and some preliminary experiments with the robotic wheelchair Mobility Aid for elderly and disabled people (MAid). MAid’s general task is to transport people with severely impaired motion skills. The authors did not set out to reinvent and redevelop the set of standard skills of so-called intelligent wheelchairs, such as Follow Wall, FollowCorridor, PassDoorway, which are commonly described in the literature. These maneuvers require motion control skills that disabled people, in spite of their disabilities, are eager to learn and quite good at using. Instead, this work focused on generalizing the approach to fine motion control by considering those maneuvers identified as very burdensome due to their duration and required concentration. One of these functions is deliberative locomotion in rapidly changing, large-scale environments, such as shopping malls, entry halls of theaters, and concourses of airports or railway stations, where tens or hundreds of people and objects move around. MAid’s performance was tested in the central station of Ulm during rush hour and in the exhibition halls of the Hannover Messe ’98, the largest industrial fair in the world. Altogether, MAid has survived more than 36 h of testing in public, crowded environments with heavy passenger traffic.

This paper presents an efficient approach for reactive collision avoidance taking into account both vehicle dynamics and nonholonomic constraints of a mobile robot. Motion commands are generated by searching the space of actuating variables. Vehicle dynamics are considered by restricting the search space to values which are reachable within the next time step. The final selection among admissible configurations is done by an objective function which trades off speed, goal-directedness and remaining distance until an obstacle is hit when moving along the chosen path. The presented approach differs from previous ones in the selective use of precalculated lookup tables. These are the key to efficiency, and they especially allow the use of any-shaped robot contours. Furthermore, obstacle information from different sources can easily be considered without preprocessing. Extensive experiments on different robots have shown robust operation in dynamic and unprepared indoor environments with speed up to 1 m/s.

This paper presents a novel ultrasonic sensing system for autonomous mobile systems. We describe how wide-angled ultrasonic transducers can be used to obtain substantial information on the environment. This can be achieved by exploiting the overlapping of the detection cones from neighboring sensors. The ultrasonic sensing system also allows the detection of multiple echoes from different echo paths for each sensor. In this way a significantly higher number of echoes can be obtained in comparison to conventional ultrasonic sensing systems for mobile robots. In order to benefit from the increased sensor information, adequate data post-processing is required. In this context we describe how an environment model can be created from real ultrasonic sensor data.

The scheduling of jobs with stochastically independent, exponentially distributed service times on identical parallel processors is considered. General sufficient conditions for optimality in expectation of priority policies for certain cost functions are given, including cases of the weighted flow time. The priority policies under consideration may be more general than the longest expected processing time (LEPT) or the shortest expected processing time (SEPT) policy. We deal with a fixed number of processors as well as certain more general resource constraints. Finally, precedence relations between jobs given by strict interval orders are admitted and an optimality result for LEPT is stated for this situation.

Experiences with the implementation of the cell tree dynamic access method for spatial databases are reported, and the results of an experimental performance comparison with the R-tree of A. Guttman (1984) and with the R-tree of T. Sellis et al. (1987) are given. Cell tree design and implementation are discussed. Although the cell tree often requires more storage space and more CPU time to answer a search query, it usually obtains the results with a lower number of disk accesses than the two rival structures.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

This paper presents a novel ultrasonic sensing system for autonomous mobile systems. We describe how wide-angled ultrasonic transducers can be used to obtain substantial information from the environment. This can be achieved by exploiting the overlapping of detection cones from neighbor sensors and by receiving cross echoes between them. The ultrasonic sensing system also allows the detection of multiple echoes from different echo paths for each sensor. In this way, a significantly higher number of echoes can be obtained in comparison to conventional ultrasonic sensing systems for mobile robots. In order to benefit from the increased sensor information, algorithms for adequate data post-processing are required. In this context, we describe how an environment model can be created from ultrasonic sensor data.

The authors describe the mechatronic design and the control system of a so-called intelligent wheelchair. The task of this system is to transport people with severely impaired motion skills. The system provides functions ranging from fully autonomous navigation in an unknown crowded environment such as a railway station to partially autonomous local maneuvers such as passing narrow door ways, operating in narrow, cluttered space, or entering a cabin in a restroom.

Article Free Access Share on IBIS—a convincing concept…but a lousy instrument? Authors: Severin Isenmann Forschungsinstitut für anwendungsorientierte, Wissensverarbeitung (FAW) Ulm, Helmholtzstraβe 16, 89081 Ulm (Germany) Forschungsinstitut für anwendungsorientierte, Wissensverarbeitung (FAW) Ulm, Helmholtzstraβe 16, 89081 Ulm (Germany)View Profile , Wolf D. Reuter Institut für Grundlagen der Planung, (IGP) der Universität Stuttgart, Keplerstraβe 11, 70174 Stuttgart (Germany) Institut für Grundlagen der Planung, (IGP) der Universität Stuttgart, Keplerstraβe 11, 70174 Stuttgart (Germany)View Profile Authors Info & Claims DIS '97: Proceedings of the 2nd conference on Designing interactive systems: processes, practices, methods, and techniquesAugust 1997 Pages 163–172https://doi.org/10.1145/263552.263602Published:01 August 1997Publication History 13citation684DownloadsMetricsTotal Citations13Total Downloads684Last 12 Months35Last 6 weeks4 Get Citation AlertsNew Citation Alert added!This alert has been successfully added and will be sent to:You will be notified whenever a record that you have chosen has been cited.To manage your alert preferences, click on the button below.Manage my AlertsNew Citation Alert!Please log in to your account Save to BinderSave to BinderCreate a New BinderNameCancelCreateExport CitationPublisher SiteeReaderPDF

In this survey paper, we first discuss the deficiencies of commercial geographic information systems and database systems when used for the management of very large geographic and environmental data sets. We then show how some recent developments in database research, especially object-oriented databases, can be utilized for an efficient data management in this domain.

TECHDOC is an implemented system demonstrating the feasibility of generating multilingual technical documents on the basis of a language-independent knowledge base. Its application domain is user and maintenance instructions, which are produced from underlying plan structures representing the activities, the participating objects with their properties, relations, and so on. This paper gives a brief outline of the system architecture and discusses some recent developments in the project: the addition of actual event simulation in the KB, steps towards a document authoring tool, and a multimodal user interface.

This paper presents a novel approach to high-resolution ultrasonic environment imaging for autonomous mobile systems. It describes the fusion of sensor data from multiple wide-angled ultrasonic transducers with overlapping detection cones for creating local environment models. A fitting technique defined as tangential regression is introduced that considers sensor properties as well as physical reflection properties of ultrasound. This allows a reliable detection and localization of straight-line segments which describe the boundary of geometric objects. Experimental results show that straight-line segments extracted at different robot locations can be aggregated and merged in order to obtain a global environment map