6616810
Robust tracking and structure from motion with sample based uncertainty representation
Geometric reconstruction of the environment from images is critical in autonomous mapping and robot navigation. Geometric reconstruction involves feature tracking, i.e., locating corresponding image features in consecutive images, and structure from motion (SFM), i.e., recovering the 3D structure of the environment from a set of correspondences between images. Although algorithms for feature tracking and structure from motion are well-established, their use in practical mobile robot applications is still difficult because of occluded features, non-smooth motion between frames, and ambiguous patterns in images. We show how a sampling-based representation can be used in place of the traditional Gaussian representation of uncertainty. We show how sampling can be used for both feature tracking and SFM and we show how they are combined in this framework. The approach is exercised in the context of a mobile robot navigating through an outdoor environment with an omnidirectional camera.
20074175
First results in omni-directional visual servoing
In this paper, we describe a visual servoing system developed as a human-robot interface to drive a mobile robot toward any chosen target. An omni-directional camera is used to get the 360° of field of view and an efficient tracking technique is developed to track the target. The use of the omni-directional geometry eliminates many of the problems common in visual tracking and makes the use of visual servoing a practical alternative for robot-human interaction. The experiments demonstrate that it is an effective and robust way to guide a robot. In particular, the experiments show robustness of the tracker to loss of template, vehicle motion, and change in scale and orientation.
3198403
Supporting reconfigurable object distribution for customized web applications
In current practice, Web applications are tightly coupled with the platforms that a particular service provider intends to support and the execution scenario envisioned at the design time. The resulting applications do not adapt well to all clients and runtime execution contexts. The goal of our research is to develop methods and software to support recon-figurable distributed applications which can be customized to specific requirements. We view a Web application as a composition of actors, i.e. distributed active objects, and apply techniques of generative programming to develop a virtual application framework which separates the logic of objects from aspects relevant to object distribution on different platforms. We describe ActorSpec, a specification system allowing programmers to express desired object distribution and assisting application generators to produce highly customized versions of an application. The resulting flexibility facilitates the development of customizable Web applications on an increasingly complex Web infrastructure.
14604279
Towards Context-Aware Web Applications
In order to guarantee certain levels of QoS, a Web application needs to adapt itself to different execution contexts. However, because of the lack of coordination support in Web platforms, service providers respond to the challenge by simply providing multiple versions of a Web application, one for each context. We argue this top-down approach is neither efficient nor scalable: developing a context-specific application requires considerable effort and expertise while the ever-changing Internet never stops generating interesting contexts which can be exploited for better deployment. As an alternative, we propose a three-layer, bottomup approach to building context-aware Web applications. At the bottom layer, we characterize a context-specific Web application with a particular component distribution plan which provides details for composing individual objects. In the middle layer, recursively defined configurations provide a bridge which relates high-level context features to low-level component distribution properties, where a configuration is a combination of configurations and/or component distribution properties. At the top level, a context management system selects desirable configurations according to the execution contexts.
16065953
An adaptive programming framework for Web applications
Web applications service a gamut of users with a mix of static and dynamic resources: requests come from different devices running different Web agents (typically, Web browsers) with different capabilities. In a majority of such interactions, services are embedded in an HTML page and displayed on a Web browser. Consequently, Web application development has been tightly coupled with the platforms that a particular site intends to support; application developers have been asked to decide "where to run what" at design time to develop services using location-specific technologies and interweave them with static resources. Such difficulties stem from lack of adequate infrastructural support for platform-agnostic development and deployment framework. This paper presents the design and implementation of a framework for Web application development which hides the heterogeneity of the Internet and the underlying interaction model. It has been meticulously designed such that it is non-intrusive and requires little change to the existing Web infrastructure. The framework is built on top of a programming model that provides a uniform view across different platforms and thus hides the heterogeneity and distributivity of the Internet. Adaptive deployment involves placement specification and compiler translation. The uniformity gives rise to rapid prototyping and development, thereby reducing costs and improving productivity. The adaptiveness enables QoS aware service provisioning.
31774598
Supporting Reconfigurable Object Distribution for Customizable Web Applications
Web applications are tightly coupled with the platforms that a particular service provider intends to support and the execution scenario envisioned at the design time Consequently, the resulting applications do not adapt well to all clients and runtime execution contexts The goal of our research is to develop methods and software to support reconfigurable distributed applications which can be customized to specific requirements Thinking in terms ofsoftware product line engineering [2], we need a product line for a given Web application, each instance of which is for a specific execution platform and context To achieve such a product line, we have to satisfy two requirements: universal accessibility and context-dependent component distribution.
35476596
A software engineering process on group collaboration of software project documents
We propose a software process that involves with the group collaboration of software project documents, which include documents for requirements, specifications, analysis, design and testing. In many software projects, there are less or no efforts to maintain a central repository of documents created and maintained by group members. We propose a process to allow all group members to contribute their documents to a Web directory, which can be located in either a Web server as a Web site or in a local directory of the members' own computers. As an illustration of the usefulness of this process, we present an example of applying it to the group collaboration of a class of graduate students in IT.