13,178 research outputs found
GR@PPA 2.7 event generator for / collisions
The GR@PPA event generator has been updated to version 2.7. This distribution
provides event generators for ( or ) + jets ( 4 jets), +
jets ( 2 jets) and QCD multi-jet ( 4 jets) production processes at
and collisions, in addition to the four bottom quark
productions implemented in our previous work (GR@PPA\_4b). Also included are
the top-pair and top-pair + jet production processes, where the correlation
between the decay products are fully reproduced at the tree level. Namely,
processes up to seven-body productions can be simulated, based on ordinary
Feynman diagram calculations at the tree level. In this version, the GR@PPA
framework and the process dependent matrix-element routines are separately
provided. This makes it easier to add further new processes, and allows users
to make a choice of processes to implement. This version also has several new
features to handle complicated multi-body production processes. A systematic
way to combine many subprocesses to a single base-subprocess has been
introduced, and a new method has been adopted to calculate the color factors of
complicated QCD processes. They speed up the calculation significantly.Comment: 21 pages, no figur
Design-Simulation-Optimization Package For A Generic 6-DOF Manipulator With A Spherical Wrist
Robot manipulators are built to meet certain predetermined performance requirements. The question of whether the robot will have the desired functionality (e.g. dexterity, accuracy, reliability, speed, etc.) needs to be answered before the robot is actualThis is an Author's Original Manuscript of an Article submitted for consideration in the Systems Analysis Modelling Simulation copyright Taylor & Francis; Systems Analysis Modelling Simulation is available online at http://www.tandfonline.com/http://www.tandfonline.com/doi/abs/10.1080/0232929031000150337#.VFpIMWNNfH
Modern Particle Physics Event Generation with WHIZARD
We describe the multi-purpose Monte-Carlo event generator WHIZARD for the
simulation of high-energy particle physics experiments. Besides the
presentation of the general features of the program like SM physics, BSM
physics, and QCD effects, special emphasis will be given to the support of the
most accurate simulation of the collider environments at hadron colliders and
especially at future linear lepton colliders. On the more technical side, the
very recent code refactoring towards a completely object-oriented software
package to improve maintainability, flexibility and code development will be
discussed. Finally, we present ongoing work and future plans regarding
higher-order corrections, more general model support including the setup to
search for new physics in vector boson scattering at the LHC, as well as
several lines of performance improvements.Comment: 7 pages; contribution to the proceedings of the conference "ACAT 2014
(Advanced Computing and Analysis Techniques in physics)", Prague, Czech
Republic, September 201
Les Houches Guidebook to Monte Carlo Generators for Hadron Collider Physics
Recently the collider physics community has seen significant advances in the
formalisms and implementations of event generators. This review is a primer of
the methods commonly used for the simulation of high energy physics events at
particle colliders. We provide brief descriptions, references, and links to the
specific computer codes which implement the methods. The aim is to provide an
overview of the available tools, allowing the reader to ascertain which tool is
best for a particular application, but also making clear the limitations of
each tool.Comment: 49 pages Latex. Compiled by the Working Group on Quantum
ChromoDynamics and the Standard Model for the Workshop ``Physics at TeV
Colliders'', Les Houches, France, May 2003. To appear in the proceeding
Cusp Points in the Parameter Space of Degenerate 3-RPR Planar Parallel Manipulators
This paper investigates the conditions in the design parameter space for the
existence and distribution of the cusp locus for planar parallel manipulators.
Cusp points make possible non-singular assembly-mode changing motion, which
increases the maximum singularity-free workspace. An accurate algorithm for the
determination is proposed amending some imprecisions done by previous existing
algorithms. This is combined with methods of Cylindric Algebraic Decomposition,
Gr\"obner bases and Discriminant Varieties in order to partition the parameter
space into cells with constant number of cusp points. These algorithms will
allow us to classify a family of degenerate 3-RPR manipulators.Comment: ASME Journal of Mechanisms and Robotics (2012) 1-1
Reducing the Barrier to Entry of Complex Robotic Software: a MoveIt! Case Study
Developing robot agnostic software frameworks involves synthesizing the
disparate fields of robotic theory and software engineering while
simultaneously accounting for a large variability in hardware designs and
control paradigms. As the capabilities of robotic software frameworks increase,
the setup difficulty and learning curve for new users also increase. If the
entry barriers for configuring and using the software on robots is too high,
even the most powerful of frameworks are useless. A growing need exists in
robotic software engineering to aid users in getting started with, and
customizing, the software framework as necessary for particular robotic
applications. In this paper a case study is presented for the best practices
found for lowering the barrier of entry in the MoveIt! framework, an
open-source tool for mobile manipulation in ROS, that allows users to 1)
quickly get basic motion planning functionality with minimal initial setup, 2)
automate its configuration and optimization, and 3) easily customize its
components. A graphical interface that assists the user in configuring MoveIt!
is the cornerstone of our approach, coupled with the use of an existing
standardized robot model for input, automatically generated robot-specific
configuration files, and a plugin-based architecture for extensibility. These
best practices are summarized into a set of barrier to entry design principles
applicable to other robotic software. The approaches for lowering the entry
barrier are evaluated by usage statistics, a user survey, and compared against
our design objectives for their effectiveness to users
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