A roadmap of problem frames research

It has been a decade since Michael Jackson introduced problem frames to the software engineering community. Since then, he has published further work addressing problem frames as well as presenting several keynote addresses. Other authors have researched problem frames, have written about their experiences and have expressed their opinions. It was not until 2004 that an opportunity presented itself for researchers in the field to gather as a community. The first International Workshop on Advances and Applications of Problem Frames (IWAAPF'04) was held at the International Conference on Software Engineering in Edinburgh on 24th May 2004. This event attracted over 30 participants: Jackson delivered a keynote address, researchers presented their work and an expert panel discussed the challenges of problem frames. Featuring in this special issue are two extended papers from the workshop, an invited contribution from Jackson in which he positions problem frames in the context of the software engineering discipline, and this article, where we provide a review of the literature

Kernel-based high-dimensional histogram estimation for visual tracking

©2008 IEEE. Personal use of this material is permitted. However, permission to reprint/republish this material for advertising or promotional purposes or for creating new collective works for resale or distribution to servers or lists, or to reuse any copyrighted component of this work in other works must be obtained from the IEEE. This material is presented to ensure timely dissemination of scholarly and technical work. Copyright and all rights therein are retained by authors or by other copyright holders. All persons copying this information are expected to adhere to the terms and constraints invoked by each author's copyright. In most cases, these works may not be reposted without the explicit permission of the copyright holder.Presented at the 15th IEEE International Conference on Image Processing, October 12–15, 2008, San Diego, California, U.S.A.DOI: 10.1109/ICIP.2008.4711862We propose an approach for non-rigid tracking that represents objects by their set of distribution parameters. Compared to joint histogram representations, a set of parameters such as mixed moments provides a significantly reduced size representation. The discriminating power is comparable to that of the corresponding full high dimensional histogram yet at far less spatial and computational complexity. The proposed method is robust in the presence of noise and illumination changes, and provides a natural extension to the use of mixture models. Experiments demonstrate that the proposed method outperforms both full color mean-shift and global covariance searches

Landmark Guided Probabilistic Roadmap Queries

A landmark based heuristic is investigated for reducing query phase run-time of the probabilistic roadmap (\PRM) motion planning method. The heuristic is generated by storing minimum spanning trees from a small number of vertices within the \PRM graph and using these trees to approximate the cost of a shortest path between any two vertices of the graph. The intermediate step of preprocessing the graph increases the time and memory requirements of the classical motion planning technique in exchange for speeding up individual queries making the method advantageous in multi-query applications. This paper investigates these trade-offs on \PRM graphs constructed in randomized environments as well as a practical manipulator simulation.We conclude that the method is preferable to Dijkstra's algorithm or the ${\rm A}^*$ algorithm with conventional heuristics in multi-query applications.Comment: 7 Page

Technology roadmap: solar photovoltaic energy - 2014 edition

Solar power enhances energy diversity and hedges against price volatility of fossil fuels, thus stabilising costs of electricity generation in the long term, argues this report. Overview Solar energy is widely available throughout the world and can contribute to reduced dependence on energy imports. As it entails no fuel price risk or constraints, it also improves security of supply. Solar power enhances energy diversity and hedges against price volatility of fossil fuels, thus stabilising costs of electricity generation in the long term. Solar PV entails no greenhouse gas (GHG) emissions during operation and does not emit other pollutants (such as oxides of sulphur and nitrogen); additionally, it consumes no or little water. As local air pollution and extensive use of fresh water for cooling of thermal power plants are becoming serious concerns in hot or dry regions, these benefits of solar PV become increasingly important. Key findings: Since 2010, the world has added more solar photovoltaic (PV) capacity than in the previous four decades. Total global capacity overtook 150 gigawatts (GW) in early 2014 The geographical pattern of deployment is rapidly changing. While a few European countries, led by Germany and Italy, initiated large-scale PV development, since 2013, the People’s Republic of China has led the global PV market, followed by Japan and the United States PV system prices have been divided by three in six years in most markets, while module prices have been divided by five This roadmap envisions PV’s share of global electricity reaching 16% by 2050, a significant increase from the 11% goal in the 2010 roadmap Achieving this roadmap’s vision of 4 600 GW of installed PV capacity by 2050 would avoid the emission of up to 4 gigatonnes (Gt) of carbon dioxide (CO2) annually This roadmap assumes that the costs of electricity from PV in different parts of the world will converge as markets develop, with an average cost reduction of 25% by 2020, 45% by 2030, and 65% by 2050, leading to a range of USD 40 to 160/MWh, assuming a cost of capital of 8% To achieve the vision in this roadmap, the total PV capacity installed each year needs to rise from 36 GW in 2013 to 124 GW per year on average, with a peak of 200 GW per year between 2025 and 2040 The variability of the solar resource is a challenge. All flexibility options – including interconnections, demand-side response, flexible generation, and storage –need to be developed to meet this challenge Appropriate regulatory frameworks – and well-designed electricity markets, in particular – will be critical to achieve the vision in this roadmap Levelised cost of electricity from new-built PV systems and generation by sector

Decoupled Sampling-Based Motion Planning for Multiple Autonomous Marine Vehicles

There is increasing interest in the deployment and operation of multiple autonomous marine vehicles (AMVs) for a number of challenging scientific and commercial operational mission scenarios. Some of the missions, such as geotechnical surveying and 3D marine habitat mapping, require that a number of heterogeneous vehicles operate simultaneously in small areas, often in close proximity of each other. In these circumstances safety, reliability, and efficient multiple vehicle operation are key ingredients for mission success. Additionally, the deployment and operation of multiple AMVs at sea are extremely costly in terms of the logistics and human resources required for mission supervision, often during extended periods of time. These costs can be greatly minimized by automating the deployment and initial steering of a vehicle fleet to a predetermined configuration, in preparation for the ensuing mission, taking into account operational constraints. This is one of the core issues addressed in the scope of the Widely Scalable Mobile Underwater Sonar Technology project (WiMUST), an EU Horizon 2020 initiative for underwater robotics research. WiMUST uses a team of cooperative autonomous ma- rine robots, some of which towing streamers equipped with hydrophones, acting as intelligent sensing and communicat- ing nodes of a reconfigurable moving acoustic network. In WiMUST, the AMVs maintain a fixed geometric formation through cooperative navigation and motion control. Formation initialization requires that all the AMVs start from scattered positions in the water and maneuver so as to arrive at required target configuration points at the same time in a completely au- tomatic manner. This paper describes the decoupled prioritized vehicle motion planner developed in the scope of WiMUST that, together with an existing system for trajectory tracking, affords a fleet of vehicles the above capabilities, while ensuring inter- vehicle collision and streamer entanglement avoidance. Tests with a fleet of seven marine vehicles show the efficacy of the system planner developed.Peer reviewe