Abstract

This paper presents a Field Programmable Gate Array (FPGA) based implementation of Acceleration Velocity Obstacle based Collision Avoidance for an omni-directional robot with acceleration constraint. Specifically a parallel architecture for collision avoidance is proposed that portrays the advantages of FPGA implementation over the sequential implementation for same processor or clock speed. FPGA based robotics is seen to gain popularity due to low cost, portability, seamless interface to hardware and most importantly due to inherent parallelism enshrined in various robotic algorithms. FPGA realization of the algorithm in a simulation test bed vindicates its efficacy and comparison with sequential implementation is also highlighted. The paper proposes three different architectures for the implementation of the proposed algorithm viz. sequential architecture; a resource constrained pipelined architecture and a hybrid pipeline parallel architecture. The performances of those three architectures have been evaluated.

Abstract

This paper proposes a robust approach for image based floor detection and segmentation from sequence of images or video. In contrast to many previous approaches, which uses a priori knowledge of the surroundings, our method uses combination of modified sparse optical flow and planar homography for ground plane detection which is then combined with graph based segmentation for extraction of floor from images. We also propose a probabilistic framework which makes our method adaptive to the changes in the surroundings. We tested our algorithm on several common indoor environment scenarios and were able to extract floor even under challenging circumstances. We obtained extremely satisfactory results in various practical scenarios such as where the floor and non floor areas are of same color, in presence of textured flooring, and where illumination changes are steep.

Abstract

We present a probabilistic method of finding the next best viewpoint that maximizes the chances of finding an object in a known environment for an indoor mobile robot. We make use of the information that is available to a robot in the form of potential locations to search for an object. Extraction of these potential locations and their representation for exploration is explained. This work primarily focuses on placing the robot at its best location in the environment to detect, recognize an object and hence do object search. With experiments done on the exploration, object recognition individually we show the robustness of this approach for object search task. We analyse and compare our method with two other strategies for localizing the object empirically and show unequivocally that the strategy based on the probabilistic formalism in general performs better than the other two.

Abstract

A semiconductor ring laser is designed so as to work as an inverted integrator coupling three of such integrators an all-optical Delta Sigma Modulator is designed. The phenomenon of injection locking and switching is used.

Abstract

On the run towards making a photonic processor, which uses the photons of visible light rather than electric current to perform digital computations we propose all optical digital logic gate library consisting of NOR, OR, AND, XOR, and two compound gates. These gates which are designed using semiconductor ring lasers (SRL) are analyzed and modeled by developing rate equations. This digital library can be used in any CAD tool developed to design integrated photonics components. The phenomenon of injection locking is used for the realization of logic gates.

Abstract

espite the advancement in the information extraction area, the task of identifying associated relations among named entities within a text document remains a significant challenge. Existing automated approaches lack human precision and they also struggle to handle erroneous documents. In this paper, we propose a crowdsourcing-based approach to improve the accuracy of the generated relations from the existing extraction techniques. Our idea is to gather judgments on the extracted relations of an article from the interested users. By contributing, the users in return remember the facts related to a document. This paper presents the complete design of the approach along with a user study done with twelve participants. Results show that the users rated the proposed system positively and were willing to contribute their time and energy for the task.

Abstract

A set of tools that demostrate the concept of a re-narration web, that aims to add alternative, target specific narrations of web documents as an extension of the web protocol with the intent of assisting a process of content dissemination and access that is inclusive of non-literate people.

Abstract

We propose Alipi, a distributed and participatory approach for re-narrating web pages for the purpose of rendering the content more accessible. This model supports alternative descriptions for a web page or parts of it via rewriting or re-narration for a given target audience by volunteers. The goal is to render the Web accessible to people across varied abilities, age, economic situation, language and geographic locations. We present the motivation, architecture and prototype implementation of Alipi.

Abstract

Workflows are ubiquitous in educational ERP and process management. The question we address in this paper is how to specify and design verifiable workflows for educational processes. To specify workflows, we borrow a simple algebraic notation from computer science. We illustrate the use of this notation through a series of typical workflow examples. We show how an algebraic specification is more expressive than a graphical specification. We then show how these algebraic specifications may be represented in the Scribble specification language, which has in built tools for verification.

Abstract

Content creation and management is an inevitable part of teaching a course. This paper describes a novel way of handling this problem using Org-mode, a recently created text based information management tool being used within the Emacs user community. We list certain desirable features, specially for the purposes of computer science courses, such as support for collaborative development and literate programming. We show how Org-mode compares favourably over other approaches like wikis and other content and course management systems. We describe why the combination of Org-mode and version control is suitable for creating and publishing content quickly, with minimum overhead in a collaborative manner.