4,404 research outputs found
Autonomous rendezvous targeting techniques for national launch system application
The rendezvous targeting techniques that can be utilized to achieve autonomous guidance for delivering a cargo to Space Station Freedom (SSF) using the National Launch System's (NLS) Heavy Lift Launch Vehicle (HLLV) and the on-orbit Cargo Transfer Vehicle (CTV) are described. This capability is made possible by advancements in autonomous navigation (Global Positioning System - GPS) on-board the CTV and SSF as well as the new generation flight computers. How the HLLV launch window can be decoupled from the CTV phasing window is described. The performance trades that have to be made to determine the length of the launch window and the phasing window between the CTV and SSF are identified and recommendations made that affect mission timelines
Workshop on Drought and Desertification: Report on the Workshop and Recommendations
The Workshop on Drought and Desertification was held in Israel from 26 to 30 May 1997. Forty-four participants from Africa, Asia, and Europe took part in the Workshop, which was sponsored by WMO. Three foreign experts provided in-depth analysis on drought and drought preparedness—Dr. O. Brunini (Campinas, Brazil), Prof. S. Mei (CAAS, Beijing, China), and Dr. D. Wilhite (University of Nebraska, USA), in addition to the Israeli lecturers. Presentations by lecturers and discussions were conducted under the following four main headings: 1. Drought and Desertification Definitions. 2. Drought Causes and Management Response. 3. Drought Monitoring and Mitigation. 4. Assessing Drought Impact and the Development of a Rational Policy
Workshop on Drought and Desertification: Report on the Workshop and Recommendations
The Workshop on Drought and Desertification was held in Israel from 26 to 30 May 1997. Forty-four participants from Africa, Asia, and Europe took part in the Workshop, which was sponsored by WMO. Three foreign experts provided in-depth analysis on drought and drought preparedness—Dr. O. Brunini (Campinas, Brazil), Prof. S. Mei (CAAS, Beijing, China), and Dr. D. Wilhite (University of Nebraska, USA), in addition to the Israeli lecturers. Presentations by lecturers and discussions were conducted under the following four main headings: 1. Drought and Desertification Definitions. 2. Drought Causes and Management Response. 3. Drought Monitoring and Mitigation. 4. Assessing Drought Impact and the Development of a Rational Policy
A plan for spacecraft automated rendezvous
An automated rendezvous approach has been developed that utilizes advances in technology to reduce real-time/near real-time flight operations support personnel to an acceptable level that is near the minimum without jeopardizing the success of the mission. The on-board flight targeting uses a rule-based system to select the pursuit vehicle phasing orbits and uses precise navigation updates from the pursuit/target spacecraft made possible by the global positioning system receivers/processors on both spacecraft to adjust the phasing orbits and achieve rendezvous. The ascent-to-orbit targeting for the pursuit vehicle has been successfully decoupled from the on-orbit orbit transfer phasing targeting. Typical launch window data have been developed for the heavy lift launch vehicle and cargo transfer vehicle for a Space Station Freedom rendezvous mission
Introduction: Home Fronts, Gender War and Conflict
Introduction to special edition of Womens History Review special edition on Gender War and Conflic
Brexit and Information Communication & Technology (ICT): Shaping ICT priorities
Information Communication and Technology (ICT) is fundamental to the delivery and support of all aspects of society in addition to significantly contributing directly to each nation’s GDP. This briefing captures key actions and requirements for the domain in the light of the UK’s decision to exit the EU. It is based on the views of ICT and other professionals from the UK and internationally. It makes the case that the UK Government needs to work overtly with a wide range of ICT experts to ensure that laws are optimized for the ICT domain and that there are targeted policies and funding strategies to support and grow the ICT domain through this change. In addition, it raises the significance of international cooperation in particular to meet environmental and ICT ethical challenges
Developing an R&D agenda to sustain the digital evidence base through time
The RecordDNA international multi-disciplinary network is exploring the question ‘In the digital era what is the concept of the record and what implications are there for the usability of the evidence base in the future?’ This is a grand challenge that requires a range of research and collaborative partnerships to sustain the shifting evidence base through time. This document sets out the case for a formalised research agenda. All of the data presented has been gathered from the RecordDNA workshops and crowdsourcing activities
RecordDNA: In the digital era what is the concept of record?
We all require access to original, authentic, usable records. However, a major issue facing society is the extent to which the concept of the digital record has been challenged and, furthermore, to what extent the digital evidence base is at risk because we do not have all the tools to maintain and sustain it through time. Rethinking the digital evidence base raises many questions. McLeod and Lomas have debated and researched the notions of fixity for well over a decade. This presentation provides the complex perspectives produced during the delivery of RecordDNA an international research network https://recorddna.wordpress.com/
Michel CORBIN, Prière et raison de la foi. Introduction à l'oeuvre de Saint Anselme de Cantorbery, Paris, Les Ed. du Cerf, Paris 1992, 476 pp., 14 x 20. [RECENSIÓN]
Enhancing Perception of Complex Sculptural Forms using Interactive Real-time Ray tracing
This paper looks at experiments into using real-time ray tracing to significantly enhance shape perception of complex three-dimensional digitally created structures. The author is a computational artist whose artistic practice explores the creation of intricate organic three-dimensional forms using simulation of morphogenesis. The generated forms are often extremely detailed, comprising tens of millions of cellular primitives. This often makes depth perception of the resulting structures difficult. His practice has explored various techniques to create presentable artefacts from the data, including high resolution prints, animated videos, stereoscopic installations, 3D printing and virtual reality.
The author uses ray tracing techniques to turn the 3D data created from his morphogenetic simulations into visible artefacts. This is typically a time-consuming process, taking from seconds to minutes to create a single frame. The latest generation of graphics processing units offer dedicated hardware to accelerate ray tracing calculations. This potentially allows the generation of ray traced images, including self-shadowed complex structures and multiple levels of transparency, from new viewpoints at frame rates capable of real-time interaction. The author presents the results of his experiments using this technology with the aim of providing significantly enhanced perception of his generated three-dimensional structures by allowing user-initiated interaction to generate novel views, and utilizing depth cues such as stereopsis, depth from motion and defocus blurring.
The intention is for these techniques to be usable to present new exhibitable works in a gallery context
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