Fast particle-mesh code for Milgromian dynamics

Context. Modified Newtonian dynamics (MOND) is a promising alternative to dark matter. To further test the theory, there is a need for fluid- and particle-dynamics simulations. The force in MOND is not a direct particle-particle interaction, but derives from a potential for which a nonlinear partial differential equation (PDE) needs to be...

Mean value first principle engine model for predicting dynamic behaviour of two-stroke marine diesel engine in various ship propulsion operations

Analysis of ship propulsion system performance is often performed using detailed hydrodynamic models to assess load changes, which are subsequently compared to static engine limits, or by detailed engine models that are rarely integrated with sufficiently detailed propulsion models for load change estimation. To investigate the dynamic engine...

Effects of adverse sea conditions on propulsion and manoeuvring performance of low-powered ocean-going cargo ship

Current EEDI (Energy Efficiency Design Index) regulations striving to reduce the installed engine power on new ships for a low EEDI may lead to underpowered ships having insufficient power when operating in adverse sea conditions. In this paper, the operational safety of a low-powered ocean-going cargo ship operating in adverse sea conditions...

A machine learning approach for propeller design and optimization: Part II

We propose and analyse an optimization method that uses a machine learning approach to solve multi-objective, constrained propeller optimization problems. The method uses an online learning strategy where explainable supervised classifiers learn the location of the Pareto front and advise search strategies. The classifiers are trained with...

A machine learning approach for propeller design and optimization: Part I

This paper introduces a machine learning approach for optimizing propellers. The method aims to improve the computational cost of optimization by reducing the number of evaluations required to find solutions. This is achieved by directing the search towards design clusters with good performance, i.e. high propulsive efficiency and low...

Integration of solid oxide fuel cell and internal combustion engine for maritime applications

The current literature on solid oxide fuel cell and internal combustion engine (SOFC-ICE) integration is focused on the application of advanced combustion technologies operating as bottoming cycles to generate a small load share. This integration approach can pose challenges for ships such as restricted dynamic capabilities and large space...

Cross-wind from linear and angular satellite dynamics: The GOCE perspective on horizontal and vertical wind in the thermosphere

The decay of satellite orbits has been used extensively to obtain thermospheric density measurements. With the introduction of accelerometers in spacecraft, the spatial resolution of these data could be increased. At the same time, the direction of the measured acceleration provides a measure for the direction of the incoming flow, and therefore...

Dynamic modelling of a direct internal reforming solid oxide fuel cell stack based on single cell experiments

Direct internal reforming enables optimal heat integration and reduced complexity in solid oxide fuel cell (SOFC)systems, but thermal stresses induced by the increased temperature gradients may inflict damage to the stack. Therefore, the development of adequate control strategies requires models that can accurately predict the temperature...

Absolute and relative orbit determination for the CHAMP/GRACE constellation

Precise orbit determination was investigated for a satellite constellation comprised of two different missions, the CHAllenging Minisatellite Payload (CHAMP) satellite and the Gravity Recovery And Climate Experiment (GRACE) twin satellites. The orbital planes of these two missions aligned closely during March to May 2005, allowing precise...

Characterization of Thermospheric Vertical Wind Activity at 225- to 295-km Altitude Using GOCE Data and Validation Against Explorer Missions

Recently, the horizontal and vertical cross wind at 225- to 295-km altitude were derived from linear acceleration measurements of the Gravity field and steady-state Ocean Circulation Explorer satellite. The vertical component of these wind data is compared to wind data derived from the mass spectrometers of the Atmosphere Explorer C and E and...

Scalable Incremental Building with Dynamic Task Dependencies

Incremental build systems are essential for fast, reproducible software builds. Incremental build systems enable short feedback cycles when they capture dependencies precisely and selectively execute build tasks efficiently. A much overlooked feature of build systems is the expressiveness of the scripting language, which directly influences the...

The semantics of name resolution in Grace

Grace is a dynamic object oriented programming language<br/>designed to aid programming education. We present a formal<br/>model of and give an operational semantics for its object<br/>model and name resolution algorithm. Our main contributions <br/>are a systematic model of Grace’s name resolution using<br/>scope graphs, relating linguistic...

Scopes describe frames: A uniform model for memory layout in dynamic semantics

Semantic specifications do not make a systematic connection between the names and scopes in the static structure of a program and memory layout, and access during its execution. In this paper we introduce a systematic approach to the alignment of names in static semantics and memory in dynamic semantics, building on the scope graph framework...

DynSem: A DSL for Dynamic Semantics Specification

The formal definition the semantics of a programming language and its implementation are typically separately defined, with the risk of divergence such that properties of the formal semantics are not properties of the implementation. In this paper, we present DynSem, a domain-specific language for the specification of the dynamic semantics of...

Dynsem: A DSL for dynamic semantics specification

The formal semantics of a programming language and its implementation are typically separately defined, with the risk of divergence such that properties of the formal semantics are not properties of the implementation. In this paper, we present DynSem, a domain-specific language for the specification of the dynamic semantics of programming...

Human hand modelling: Kinematics, dynamics, applications

An overview of mathematical modelling of the human hand is given. We consider hand models from a specific background: rather than studying hands for surgical or similar goals, we target at providing a set of tools with which human grasping and manipulation capabilities can be studied, and hand functionality can be described. We do this by...

Stratego/XT 0.17. A Language and Toolset for Program Transformation

Preprint of paper published in: Science of Computer Programming (Elsevier), 72 (1-2), 2008; doi:10.1016/j.scico.2007.11.003 Stratego/XT is a language and toolset for program transformation. The Stratego language provides rewrite rules for expressing basic transformations, programmable rewriting strategies for controlling the application of rules...

Aiming at a 1-cm orbit for low earth orbiters: Reduced-dynamic and kinematic precise orbit determination

The computation of high-accuracy orbits is a prerequisite for the success of Low Earth Orbiter (LEO) missions such as CHAMP, GRACE and GOCE. The mission objectives of these satellites cannot be reached without computing orbits with an accuracy at the few cm level. Such a level of accuracy might be achieved with the techniques of reduced-dynamic...