1,841,755 research outputs found
PRISMA-RT (benchmark)database
No full textPRISMA-RT database is een collectieve meldingsdatabase waarbij radiotherapie-instellingen data van meldingsanalyses benchmarken.
In 2008 is de vereniging PRISMA-RT, een samenwerking van Nederlandse radiotherapie instellingen opgericht. PRISMA-RT is een acroniem voor Prevention, Recovery and Information System for Monitoring and Analyses in RadioTherapy. Alle leden van de PRISMA-RT hebben een meldingscommissie die multidisciplinair is samengesteld. Het melden van procesafwijkingen wordt digitaal gedaan door alle professionals betrokken bij het radiotherapie proces. Het PRISMA proces bevat 7 stappen: verzamelen, selectie en onderzoek, beschrijving voorval, classificatie, invoering, interpretatie en training. Iedere (bijna)-incidentmelding wordt geanalyseerd middels een boomachtige structuur (incident oorzakenboom) en waarbij onderliggende oorzaken worden geïdentificeerd.
Alleen de basisoorzaken codes en collectieve contextvariabelen worden gebruikt in de benchmarkdatabase en deze zijn door alle leden in te zien. De rest van de meldingsdata (van de leden) is niet zichtbaar. Periodiek worden er geanonimiseerde benchmarkanalyses opgesteld door het expertteam van de vereniging en projecten geïnitieerd op basis van de benchmarkdata
PRISMA 2001, The Kernel
Get PDFPRISMA is�een macrosector-model van de Nederlandse economie, geijkt op het CPB-model Athena. Het is geschikt voor analyses voor de middellange en lange termijn. Meerwaarde van het model is het onderscheiden van grootteklassen en de module die�aantallen ondernemers verklaart. Actueel gebruik�van het�model is�analyse van economische effecten van R&D-subsidies, analyse van economische effecten van administratieve lasten, en�het vaststellen van drie scenario's voor de middellangetermijn�met betrekking tot de ontwikkeling van het MKB en het aantal ondernemers. Dit rapport geeft een uitgebreide beschrijving.
PRISMA - Formation Flying Project Close to Launnch
No full textThe PRISMA project is a technical demonstration mission for formation flying and rendezvous in
space. The mission can be considered as an in-obit test-bed where different experiments
involving Guidance, Navigation and Control (GNC) algorithms, sensors and actuators can be
tested. The project is also a demonstration mission for two novel propulsion technologies. The
project consists of two satellites, of which one is manoeuvring relative to the other, using
different sensors and algorithms.
The project is run by Swedish Space Corporation (SSC) with important contributions from the
German Aerospace Center (DLR), the French Space Agency (CNES) and the Technical
University of Denmark (DTU). The project started in beginning of 2005. The satellites are now
basically on the launch pad, scheduled for launch on June 15, 2010 from the Russian site Yasny.
The ground segment, consisting of a Mission and Operations Control Centre in Solna, Sweden,
has been established and is ready for launch
GPS-Based Real-Time Navigation for the PRISMA Formation Flying Mission
No full textThe paper addresses the design, implementation and validation of the on-board navigation system for the PRISMA technology demonstration mission. The objective of the navigation system is to provide in real-time absolute and relative orbit information for the PRISMA space segment which consists of two satellites flying in formation in Low Earth Orbit. The key drivers for the design of the navigation system are the accuracy requirements on the absolute and relative orbit determination which amount to 2 m and 0.1 m respectively (3D, r.m.s.). Furthermore, a high level of robustness and flexibility imposed by the numerous formation flying scenarios is required during the mission lifetime of about eight months. The paper focuses on the description of the navigation software architecture and algorithms. In contrast to earlier approaches that typically separate the GPS-based navigation task into the independent reconstruction of absolute and relative states, here a single reduced-dynamic Kalman filter has been developed which processes pseudorange and carrier-phase data from both spacecraft in order to exploit the full GPS measurements information at all times. Emphasis is given to the validation of the software via real-world simulations. The flight application is executed on a LEON2 processor in order to evaluate the orbit determination performance in real-time using a representative PRISMA flight hardware
PRISMA - An Autonomous Formation Flying Mission
No full textPRISMA is an ongoing satellite project comprising two satellites. The project constitutes an in-orbit test bed for Guidance, Navigation and Control (GNC) algorithms and sensors for advanced closed-loop formation flying and rendezvous. The satellites will be launched in a low earth orbit and carry out a series of maneuvering experiments and sensor experiments during a mission time of 8-10 months. Autonomous formation flying in decimeter precision will be demonstrated using relative GPS and Formation Flying RF metrology instruments. Vision based methods using a modified star camera will demonstrate autonomous homing and rendezvous from hundreds of kilometers down to close proximity. Proximity operations based on GPS or optical information shall be demonstrated all the way down to almost physical contact. A new environmentally friendly, non-toxic chemical propulsion system as well as a new MEMS microthruster system will be flight demonstrated
Preparation, Handover, and Conduction of PRISMA Mission Operations at GSOC
No full textThe experimental satellite project PRISMA was initiated in 2005 by Sweden, France, Denmark, and Germany, with the Swedish Space Cooperation (SSC) as the project lead. The purpose was the demonstration of necessary techniques and the validation of the respective sensor technology for future missions that involve close formation flight and rendezvous in space. At that time, the German Aerospace Center DLR was not only involved in providing satellite GPS hardware and navigation software components but also as one of the experimenters for GPS-based navigation and autonomous formation flight. The idea of also conduction a part of the flight operations phase from Germany came into discussion at the end of 2009, with the purpose of sharing mission operations cost. This was agreed by Sweden and Germany shortly before launch of the two PRISMA satellites, which took place in June 2010. Nine months later, mission operations were handed over from SSC’s control center in Solna, Stockholm, to the German Space Operations Center (GSOC) in Oberpfaffenhofen, Germany. After successful operations by GSOC, the re-hand over of the mission back to Solna was performed in August 2011.
The baseline concept for the German PRISMA ground segment foresaw cloning of the Swedish ground segment developed by SSC at GSOC to minimize the development and test effort, but specific adaptations were needed to integrate PRISMA into GSOC’s multimission environment. Furthermore, the original station network, which consisted only of the Kiruna ground station in North Sweden, was extended by two additional DLR ground stations in Weilheim, Germany, and in Inuvik, Canada. That extension proved especially beneficial to the shift concept.
Another important aspect was the training of the German operations personnel in a short time. This was realized by training on the job concept, which kept the additional workload for teaching and training on acceptable levels and at the same time supported the Swedish flight operations team during their operations phase.
This paper gives an overview of the GSOC ground segment and the flight operations activities. It reflects the challenges with regard to personnel and to the technical implementation of PRISMA flight operations at GSOC with limited available time. It also summarizes the lessons learned after five months of successful flight operations
Membuat benda berbentuk prisma dengan aneka bahan.
No full textBuku ini berisi petunjuk-petunjuk mengenai cara merancang dan membuat aneka benda bebentuk prisma menggunakan berbagi bahan.iv, 60 hlm.: ilus.; 21 cm
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