72,197 research outputs found
Numerical simulation of the stress-strain state of the dental system
We present mathematical models, computational algorithms and software, which
can be used for prediction of results of prosthetic treatment. More interest
issue is biomechanics of the periodontal complex because any prosthesis is
accompanied by a risk of overloading the supporting elements. Such risk can be
avoided by the proper load distribution and prediction of stresses that occur
during the use of dentures. We developed the mathematical model of the
periodontal complex and its software implementation. This model is based on
linear elasticity theory and allows to calculate the stress and strain fields
in periodontal ligament and jawbone. The input parameters for the developed
model can be divided into two groups. The first group of parameters describes
the mechanical properties of periodontal ligament, teeth and jawbone (for
example, elasticity of periodontal ligament etc.). The second group
characterized the geometric properties of objects: the size of the teeth, their
spatial coordinates, the size of periodontal ligament etc. The mechanical
properties are the same for almost all, but the input of geometrical data is
complicated because of their individual characteristics. In this connection, we
develop algorithms and software for processing of images obtained by computed
tomography (CT) scanner and for constructing individual digital model of the
tooth-periodontal ligament-jawbone system of the patient. Integration of models
and algorithms described allows to carry out biomechanical analysis on
three-dimensional digital model and to select prosthesis design.Comment: 19 pages, 9 figure
Challenging the Computational Metaphor: Implications for How We Think
This paper explores the role of the traditional computational metaphor in our thinking as computer scientists, its influence on epistemological styles, and its implications for our understanding of cognition. It proposes to replace the conventional metaphor--a sequence of steps--with the notion of a community of interacting entities, and examines the ramifications of such a shift on these various ways in which we think
Modular synthesis of discrete controllers
This paper presents supervisory control theory in a process-algebraic setting, and proposes a way of synthesising modular supervisors that guarantee nonblocking. The framework used includes the possibility of hiding actions which results in nondeterminism. As modularity crucially depends on the process equivalence used, the paper studies possible equivalences and points out that, in order to be consistent with respect to the nonblocking property and to supervisor synthesis, a conflict-preserving equivalence must be used. It applies the results to synthesise nonblocking modular supervisors for a manufacturing system
The communication processor of TUMULT-64
Tumult (Twente University MULTi-processor system) is a modular extendible multi-processor system designed and implemented at the Twente University of Technology in co-operation with Oce Nederland B.V. and the Dr. Neher Laboratories (Dutch PTT). Characteristics of the hardware are: MIMD type, distributed memory, message passing, high performance, real-time and fault tolerant. A distributed real-time operating system has been realized, consisting of a multi-tasking kernel per node, inter process communication via typed messages and a distributed file system. In this paper first a brief description of the system is given, after that the architecture of the communication processor will be discussed. Reduction of the communication overhead due to message passing will be emphasized.\ud
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One-Chip Solution to Intelligent Robot Control: Implementing Hexapod Subsumption Architecture Using a Contemporary Microprocessor
This paper introduces a six-legged autonomous robot managed by a single
controller and a software core modeled on subsumption architecture. We begin by
discussing the features and capabilities of IsoPod, a new processor for
robotics which has enabled a streamlined implementation of our project. We
argue that this processor offers a unique set of hardware and software
features, making it a practical development platform for robotics in general
and for subsumption-based control architectures in particular. Next, we
summarize original ideas on subsumption architecture implementation for a
six-legged robot, as presented by its inventor Rodney Brooks in 1980s. A
comparison is then made to a more recent example of a hexapod control
architecture based on subsumption. The merits of both systems are analyzed and
a new subsumption architecture layout is formulated as a response. We conclude
with some remarks regarding the development of this project as a hint at new
potentials for intelligent robot design, opened by a recent development in
embedded controller market
The Fraunhofer Quantum Computing Portal - www.qc.fraunhofer.de - A web-based Simulator of Quantum Computing Processes
Fraunhofer FIRST develops a computing service and collaborative workspace
providing a convenient tool for simulation and investigation of quantum
algorithms. To broaden the twenty qubit limit of workstation-based simulations
to the next qubit decade we provide a dedicated high memorized Linux cluster
with fast Myrinet interconnection network together with a adapted parallel
simulator engine. This simulation service supplemented by a collaborative
workspace is usable everywhere via web interface and integrates both hardware
and software as collaboration and investigation platform for the quantum
community. The beta test version realizes all common one, two and three qubit
gates, arbitrary one and two bit gates, orthogonal measurements as well as
special gates like Oracle, Modulo function, Quantum Fourier Transformation and
arbitrary Spin-Hamiltonians up to 31 qubits. For a restricted gate set it
feasible to investigate circuits with up to sixty qubits. URL:
http://www.qc.fraunhofer.d
A new Slow Control and Run Initialization Byte-wise Environment (SCRIBE) for the quality control of mass-produced CMS GEM detectors
The CMS collaboration aims at improving the muon trigger and tracking
performance at the HL-LHC by installing new Gas Electron Multiplier (GEM)
chambers in the endcaps of the CMS experiment. Construction and commissioning
of GEM chambers for the first muon endcap stations is ramping up in several
laboratories using common quality control protocols. The SCRIBE framework is a
scalable and cross-platform webbased application for the RD51 Scalable Readout
System (SRS) that controls data acquisition and analyzes data in near real
time. It has been developed mainly to simplify and standardize measurements of
the GEM chamber response uniformities with x-rays across all production sites.
SCRIBE works with zero suppression of raw SRS pulse height data. This has
increased acquisition rates to 5 kHz for a CMS GEM chamber with 3072 strips and
allows strip-by-strip response comparisons with a few hours of data taking.
SCRIBE also manages parallel data reconstruction to provide near real-time
feedback on the chamber response to the user. Preliminary results on the
response performance of the first mass-produced CMS GEM chambers commissioned
with SCRIBE are presented
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