101 resultados para Techow, Ernst-Werner.


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Acoustic sensors play an important role in augmenting the traditional biodiversity monitoring activities carried out by ecologists and conservation biologists. With this ability however comes the burden of analysing large volumes of complex acoustic data. Given the complexity of acoustic sensor data, fully automated analysis for a wide range of species is still a significant challenge. This research investigates the use of citizen scientists to analyse large volumes of environmental acoustic data in order to identify bird species. Specifically, it investigates ways in which the efficiency of a user can be improved through the use of species identification tools and the use of reputation models to predict the accuracy of users with unidentified skill levels. Initial experimental results are reported.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Acute exercise has been shown to exhibit different effects on human sensorimotor behavior; however, the causes and mechanisms of the responses are often not clear. The primary aim of the present study was to determine the effects of incremental running until exhaustion on sensorimotor performance and adaptation in a tracking task. Subjects were randomly assigned to a running group (RG), a tracking group (TG), or a running followed by tracking group (RTG), with 10 subjects assigned to each group. Treadmill running velocity was initially set at 2.0 m s− 1, increasing by 0.5 m s− 1 every 5 min until exhaustion. Tracking consisted of 35 episodes (each 40 s) where the subjects' task was to track a visual target on a computer screen while the visual feedback was veridical (performance) or left-right reversed (adaptation). Resting electroencephalographic (EEG) activity was recorded before and after each experimental condition (running, tracking, rest). Tracking performance and the final amount of adaptation did not differ between groups. However, task adaptation was significantly faster in RTG compared to TG. In addition, increased alpha and beta power were observed following tracking in TG but not RTG although exhaustive running failed to induce significant changes in these frequency bands. Our results suggest that exhaustive running can facilitate adaptation processes in a manual tracking task. Attenuated cortical activation following tracking in the exercise condition was interpreted to indicate cortical efficiency and exercise-induced facilitation of selective central processes during actual task demands.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In topological mapping, perceptual aliasing can cause different places to appear indistinguishable to the robot. In case of severely corrupted or non-available odometry information, topological mapping is difficult as the robot is challenged with the loop-closing problem; that is to determine whether it has visited a particular place before. In this article we propose to use neighbourhood information to disambiguate otherwise indistinguishable places. Using neighbourhood information for place disambiguation is an approach that neither depends on a specific choice of sensors nor requires geometric information such as odometry. Local neighbourhood information is extracted from a sequence of observations of visited places. In experiments using either sonar or visual observations from an indoor environment the benefits of using neighbourhood clues for the disambiguation of otherwise identical vertices are demonstrated. Over 90% of the maps we obtain are isomorphic with the ground truth. The choice of the robot’s sensors does not impact the results of the experiments much.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The application of computer-aided design and manufacturing (CAD/CAM) techniques in the clinic is growing slowly but steadily. The ability to build patient-specific models based on medical imaging data offers major potential. In this work we report on the feasibility of employing laser scanning with CAD/CAM techniques to aid in breast reconstruction. A patient was imaged with laser scanning, an economical and facile method for creating an accurate digital representation of the breasts and surrounding tissues. The obtained model was used to fabricate a customized mould that was employed as an intra-operative aid for the surgeon performing autologous tissue reconstruction of the breast removed due to cancer. Furthermore, a solid breast model was derived from the imaged data and digitally processed for the fabrication of customized scaffolds for breast tissue engineering. To this end, a novel generic algorithm for creating porosity within a solid model was developed, using a finite element model as intermediate.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In this paper we describe the dynamic simulation of an 18 degrees of freedom hexapod robot with the objective of developing control algorithms for smooth, efficient and robust walking in irregular terrain. This is to be achieved by using force sensors in addition to the conventional joint angle sensors as proprioceptors. The reaction forces on the feet of the robot provide the necessary information on the robots interaction with the terrain. As a first step we validate the simulator by implementing movement control by joint torques using PID controllers. As an unexpected by-product we find that it is simple to achieve robust walking behaviour on even terrain for a hexapod with the help of PID controllers and by specifying a trajectory of only a few joint configurations.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Adult education plays an important role in global economic development and features prominently in debates about changing requirements of post-industrial knowledge societies. This dominant technical-instrumental understanding of adult education in public discourse masks the transformative function of certain types of adult education - that is, the possibilities of adult education to improve social justice issues such as workers’ rights, human rights, civic participation in governance and socially just development. Given the increasing social stratification between and within the North and South in the global era, the potential of adult education to effect social change has been rediscovered by organisations within global civil society, namely international non-governmental organisations (INGOs). The broad objective of this research was to carry out an in-depth qualitative case study of a human rights advocacy program provided by a Northern INGO predominantly operating within the global South. The study analyses how participants see this program in terms of its potential to contribute to progressive social change in their home communities across the Asia-Pacific region. The following questions guided the study: 1. To what extent does this adult education program challenge existing systems of domination and marginalisation? 2. How did completion of the program affect participants’ views of their abilities to facilitate social action within their communities? Data sources for this research were interviews with 19 participants and staff and questionnaires from 28 participants of the program from a variety of countries in the Asia-pacific region. The gap in the literature that this study addressed is that existing empirical research sidelines the analysis of the globalisation, adult education, and social change nexus from a perspective that takes the marginalised other seriously, tending instead to mirror the material subjugation of the South in discursive practices. Social change is highly context-specific and strategies to advance it depend on the way in which people understand their reality and are affected by adverse social conditions. The present study employed a postcolonial framework that provided a holistic approach to analysing adult education for social change inclusive of material, political, and social conditions and the interplay between these from the local to the global level. The program convincingly exemplified an example of adult education for counter-hegemonic resistance against the dominant neoliberal discourse. It achieved this by enabling participants, based on Freirian pedagogical principles, to locate the problem of social change and frame their strategies to address it within mutually constitutive local and global developments and the discourses that describe them. It provided the underpinning knowledge and skills for effective advocacy and created opportunities to build networks between various stakeholders. At minimum, most advocates accord their participation in the program a supporting role in enhancing their ability to examine causes for social injustices and ways to address these. Some advocates even regarded their program participation as fundamental in understanding these issues. Almost all participants reported an increased skill-set that enabled them to become more effective advocates.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Electronic services are a leitmotif in ‘hot’ topics like Software as a Service, Service Oriented Architecture (SOA), Service oriented Computing, Cloud Computing, application markets and smart devices. We propose to consider these in what has been termed the Service Ecosystem (SES). The SES encompasses all levels of electronic services and their interaction, with human consumption and initiation on its periphery in much the same way the ‘Web’ describes a plethora of technologies that eventuate to connect information and expose it to humans. Presently, the SES is heterogeneous, fragmented and confined to semi-closed systems. A key issue hampering the emergence of an integrated SES is Service Discovery (SD). A SES will be dynamic with areas of structured and unstructured information within which service providers and ‘lay’ human consumers interact; until now the two are disjointed, e.g., SOA-enabled organisations, industries and domains are choreographed by domain experts or ‘hard-wired’ to smart device application markets and web applications. In a SES, services are accessible, comparable and exchangeable to human consumers closing the gap to the providers. This requires a new SD with which humans can discover services transparently and effectively without special knowledge or training. We propose two modes of discovery, directed search following an agenda and explorative search, which speculatively expands knowledge of an area of interest by means of categories. Inspired by conceptual space theory from cognitive science, we propose to implement the modes of discovery using concepts to map a lay consumer’s service need to terminologically sophisticated descriptions of services. To this end, we reframe SD as an information retrieval task on the information attached to services, such as, descriptions, reviews, documentation and web sites - the Service Information Shadow. The Semantic Space model transforms the shadow's unstructured semantic information into a geometric, concept-like representation. We introduce an improved and extended Semantic Space including categorization calling it the Semantic Service Discovery model. We evaluate our model with a highly relevant, service related corpus simulating a Service Information Shadow including manually constructed complex service agendas, as well as manual groupings of services. We compare our model against state-of-the-art information retrieval systems and clustering algorithms. By means of an extensive series of empirical evaluations, we establish optimal parameter settings for the semantic space model. The evaluations demonstrate the model’s effectiveness for SD in terms of retrieval precision over state-of-the-art information retrieval models (directed search) and the meaningful, automatic categorization of service related information, which shows potential to form the basis of a useful, cognitively motivated map of the SES for exploratory search.