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Choenni, S. (author), Bruggeman, B. (author)Research and development in database technology evolves in several directions, which are not necessarily divergent. A number of these directions might be promising for military information systems as well. In this paper, we discuss the potentials of multi-media databases and data mining. Both directions focus on the handling of a vague...report 2000
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Delil, A.A.M. (author)The rationale behind the CIMEX-3 experiment is explained. It is justified (supported by many references) why such an experiment shall be carried out, by discussing its historical background, its objectives and its preliminary configuration. It is shown that CIMEX-3 is not intended only as an experiment to get a better knowledge of the physics of...report 2000
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Choenni, S. (author), Blanken, H. (author)Physical database design can be marked as a crucial step in the overall design process of databases. The outcome of physical database design is a physical schema which describes the storage and access structures of the stored database. The selection of an efficient physical schema is an NP-complete problem. A significant number of efforts has...report 2000
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Schippers, H. (author), Bandinelli, M. (author), Bertoncini, F. (author), Sensani, S. (author)The design of antennas on spacecraft and aircraft as well as the prediction of Radar Cross Sections of fighter aircraft require the geometrical modelling and electro-magnetic analysis of antennas and scattering objects. The electro-magnetic analysis can be performed by means of classical computational methods, which are based on the Stratton-Chu...report 2000
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Prins, J.J.M. (author)Sloshsat FLEVO is a mini satellite for the study of liquid dynamics and liquid management problems in space. The behavior of water in an instrumented tank in the satellite will be monitored to help understand how sloshing affects the attitude and orbit control of space vehicles. The micro-gravity disturbance by liquid in a tank is determined as...report 2000
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Delil, A.A.M. (author)Multiphase flow, the simultaneous flow of the different phases (states of matter) gas, liquid and solid, strongly depends on the level and direction of gravitation, since these influence the spatial distribution of the phases, having different densities. Many investigations concern behaviour of liquid-solid flows (e.g. in mixing, crystal growing...report 2000
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Verhoef, W. (author)The estimation of biophysical parameters of vegetation canopies from optical remote sensing data is very important for the study of land surface processes. Traditionally, this has been realised mostly by means of spectral indices, e.g. the normalised difference vegetation index (NDVI), which is derived from spectral reflectances or radiances in...report 2000
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Verhoef, W. (author)Lifting has been recognised as an effective numerical technique to realise linear transformations to digital data in integer-to-integer form, which guarantees perfect reversibility. When applied to decorrelate digital hyperspectrai images in the spectral and spatial domains, lifting can be applied to accomplish lossless data compression....report 2000
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Wubben, F.J.M. (author), Vogels, M.E.S. (author), ten Have, H.B.G. (author)In the Netherlands, noise exposure forecasting is based on the assumption that lateral track dispersion, for both take-off and landing, can be represented by a symmetrical probability distribution. Radar track observations at Amsterdam Airport Schiphol (AAS) show that the actual track dispersion is certainly not symmetrical. As a result,...report 2000
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Elsenaar, A. (author)Flow separation and vorticity generation are closely connected. When the flow leaves the trailing edge of a wing, a vorticity layer is formed, directly related to the lift of the wing and carrying streamwise vorticity. Boundary layers, in which the viscous flow very close to the wing surface is confined, carry vorticity in crosswise direction,...report 2000
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Wanhill, R.J.H. (author), Koolloos, M.F.J. (author)Aircraft structures are susceptible to fatigue and corrosion damage, notably at joints. There may be interactions between fatigue and corrosion, especially as aircraft age. Longitudinal lap splices from several types of transport aircraft pressure cabins were disassembled and investigated for Multiple Site Damage (MSD) fatigue cracking and...report 2000
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Kogenhop, O. (author)The main object of this report is to investigate whether it is possible to determine the propagation lifetime for complicated gas turbine components by performing crack growth calculations. Therefore a certain calculation course/strategy is necessary, which will be shown in this report. As a case study the present 2"''-stage fan disc of a Pratt ...report 2000
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Hoekstra, J.M. (author), Ruigrok, R. (author), van Gent, R.N.W.H. (author), Visser, J. (author), Gijsbers, B. (author)NLR has investigated the feasibility of Free Flight concepts with airbome separation during several years of research in collaboration with NASA, the FAA and the RLD (Dutch Civil Aviation Authorities). Issues that have been addressed are: • conflict detection & resolution methods • complex conflict geometries • pilot workload • pilot...report 2000
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Hagmeijer, R. (author), de Boer, A. (author), Tinga, T. (author), ten Hoeve, H.J. (author)An overview of the activities on integrated analysis of gas turbine components at the National Aerospace Laboratory NLR in the Netherlands is presented. Key elements are the multidisciplinary frame-work including Engine System Performance, Fluid Dynamics Analysis, Heat Flow Analysis, Stress Analysis and Life Assessment, and a complementary...report 2000
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Everdij, M.H.C. (author), Blom, H.A.P. (author)Piecewise Deterministic Markov Processes (PDPs) are known as the largest class of Markov processes virtually describing all continuous-time processes not involving difftisions. In general the state space of a PDP is of hybrid type, i.e. a tensor product of a discrete set and a continuousvalued space. Since Stochastic Petri Nets have proven to be...report 1999
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- Verhoef, W. (author) report 1998
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Demmenie, E.A. (author), de Bruin, A.C. (author), Klaver, E. (author)Pressure waves, that are generated when a high speed train enters a tiinnel, can cause annoyance to train passengers (rapid pressure fluctuations acting on the train) and for people living near the tunnel (micro-pressure wave). To improve train passenger comfort the effect of various pressure relieving measures (i.e. shafts and porous walls)...report 1998
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Schoonmade, M. (author)Liquid sloshing in partially filled tanks is an extensive subject, with scientific, numerical and engineering interest. An important application is in vehicle dynamics, such as in space vehicles, gaining importance from foreseen space station activities. When liquid is not settled by a strong body force, as is in the case in many space...report 1997
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de Brouwer, M.G.A. (author), Verduijn, F.F. (author), Donkers, J.W. (author)The rapidly approaching third millennium will start with a permanent manned presence in space. Continuous operations of the International Space Station, followed by eventually unavoidable manned travels to the Moon and Mars, require near-closed loop systems to support essential aspects of life: breathing, drinking and eating. Recycling decreases...report 1997
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Delil, A.A.M. (author)Future (commercial) satellites will require accurate propellant gauging systems, in order to meet the end-of-life reorbiting requirement and the need for replacement planning. A capacitivc Gauging Sensor Unit is currently being developed for the Meteosat Second Generation spacecraft. Its measurement principle is based on the difference of the...report 1997