Computing the output distribution and selection probabilities of a stack filter from the DNF of its positive Boolean function

Many nonlinear filters used in practise are stack filters. An algorithm is presented which calculates the output distribution of an arbitrary stack filter S from the disjunctive normal form (DNF) of its underlying positive Boolean function. The so called selection probabilities can be computed along the way.Comment: This is the version published in Journal of Mathematical Imaging and Vision, online first, 1 august 201

Adaptive Computer Vision: Online Learning for Object Recognition

Bekel H, Bax I, Heidemann G, Ritter H. Adaptive Computer Vision: Online Learning for Object Recognition. In: Rasmussen CE, Bülthoff HH, Giese MA, Schölkopf B, eds. Pattern Recognition. Proceedings. Lecture notes in computer science. Vol 3175. Berlin: Springer-Verlag; 2004: 447-454.The "life" of most neural vision systems splits into a one-time training phase and an application phase during which knowledge is no longer acquired. This is both technically inflexible and cognitively unsatisfying. Here we propose an appearance based vision system for object recognition which can be adapted online, both to acquire visual knowledge about new objects and to correct erroneous classification. The system works in an office scenario, acquisition of object knowledge is triggered by hand gestures. The neural classifier offers two ways of training: Firstly, the new samples can be added immediately to the classifier to obtain a running system at once, though at the cost of reduced classification performance. Secondly, a parallel processing branch adapts the classification system thoroughly to the enlarged image domain and loads the new classifier to the running system when ready

From images via symbols to contexts: using augmented reality for interactive model acquisition

Systems that perform in real environments need to bind the internal state to externally perceived objects, events, or complete scenes. How to learn this correspondence has been a long standing problem in computer vision as well as artificial intelligence. Augmented Reality provides an interesting perspective on this problem because a human user can directly relate displayed system results to real environments. In the following we present a system that is able to bootstrap internal models from user-system interactions. Starting from pictorial representations it learns symbolic object labels that provide the basis for storing observed episodes. In a second step, more complex relational information is extracted from stored episodes that enables the system to react on specific scene contexts

Backlash Against Democracy: The Regulation of Civil Society in Africa

This paper builds on TrustAfrica funded research regarding the legislative environment for non-governmental organizations. The first section of this paper provides a brief overview of the recent history of state-civil society relations in Africa. The second section examines the current trend in repressive NGO legislation in Zambia, Ethiopia, and Zimbabwe, which include: (1) barriers to entry; (2) barriers to operational activity and free speech; and (3) barriers to resources. The third and final section frames this trend within the history of democratization in Africa and identifies new directions for research and analysis

Egranary as a Digital Resource in Uganda: Preliminary Findings

In this paper, we address preliminary findings from a digital literacy study on the use the portable digital library, eGranary, currently being conducted in a rural Ugandan school. The eGranary system is an intranet that comprises a 750Gb harddrive with specialized browsing software, which can be attached to a PC or a local area network. It contains approximately 10 million educational documents, including Wikipedia, which can be searched like the internet (see www.egranary.org). Drawing on theories of new literacies and identities, the two research questions we are addressing in our current project are as follows: (i) how does eGranary function as a placed resource in Ugandan society? (ii) to what extent do identities shift as teachers learn from and contribute to global knowledge production? These research questions are centrally concerned with the innovative use of educational resources to promote social inclusion in poorly resourced regions of the world.\u

Software support for manufacturing operations in Belgian SMEs: one size fits all?

Manufacturing companies face a big challenge to bridge the gap between their business and manufacturing processes. The urge to increase efficiency makes it necessary to align the business and manufacturing processes. Small and Medium-sized Enterprises (SMEs) experience several barriers to adopt software support for manufacturing operations. This paper gives an overview of a research study conducted in Belgian SMEs. The research studied the current adoption of software support for manufacturing operations and the barriers that SMEs experience to invest in this type of software. The study is concluded with a number of considerations to enable the adoption of software support for manufacturing operations by SMEs

Safeguarding Massive MIMO Aided HetNets Using Physical Layer Security

This paper exploits the potential of physical layer security in massive multiple-input multiple-output (MIMO) aided two-tier heterogeneous networks (HetNets). We focus on the downlink secure transmission in the presence of multiple eavesdroppers. We first address the impact of massive MIMO on the maximum receive power based user association. We then derive the tractable upper bound expressions for the secrecy outage probability of a HetNets user.We show that the implementation of massive MIMO significantly improves the secrecy performance, which indicates that physical layer security could be a promising solution for safeguarding massive MIMO HetNets. Furthermore, we show that the secrecy outage probability of HetNets user first degrades and then improves with increasing the density of PBSs