15,718 research outputs found
A model for a flywheel automatic assistedmanual transmission
This paper is focused on the model and dynamical analysis of a flywheel assisted transmis- sion aiming at reducing the torque gap during gear shift manoeuvres. A completely passive device, consisting of a planetary gear set mounting a flywheel on the sun gear shaft, allows to continuously connect the engine to the load shaft. Depending on the operating condi- tions, it can either absorb energy from the engine or deliver the previously stored kinetic energy to the wheels when the clutch is disengaged, thus allowing better vehicle performances and/or ride comfort through a suitable coordinated control of engine and clutc
Discrete Element Study Mixing in an Industrial Sized Mixer
The mixing quality as function of the operating time is one major parameter to be considered for the design of industrial sized mixers. Different mixer types with different operating principles can be found for different special tasks, and the question about the proper quantity that quantifies mixing is still open.\ud
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Computer simulations based on the Discrete Element Method (DEM) provide a close,\ud
detailed look inside the mixing device and process and thus a better understanding of the particle flow in the mixer. Therefore such simulations can be used for an improvement of the mixer design or operating conditions.\ud
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DEM simulations allow the “online”- and “inline”-measurement of the mixing quality over time. But in mixers with a complex design it is not only interesting at which time a certain mixing quality is reached. It is also interesting to analyse which part of the mixing (either location in the device or process conditions) are of special importance due to a strong effect on the mixing process.\ud
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Therefore, a time- and space-dependent analysis was developed, using several approaches for mixing-quality that can be found in literature. More explicitly, the particle numbers, the number of contacts between different particle-types, and the generalized mean mixing index (GMMI) have been examined. All have their regimes of reasonable use that will be discussed - the most promising approaches will be compared
Market study of financial mechanism for climate risk management in the livestock sector in Guatemala
This document presents the market study results to identify relevant information, characteristics, and conditions of an enabling environment for climate resilience financial services in livestock in the Peten, Izabal, Jalapa, Jutiapa, and Santa Rosa departments of Guatemala. It was developed by YAPU Solutions as a consultancy deliverable for the Alliance Bioversity International and the International Center for Tropical Agriculture (CIAT) and is part of the Livestock, Climate, and System Resilience initiative of the CGIAR portfolio
Towards a Formalism-Based Toolkit for Automotive Applications
The success of a number of projects has been shown to be significantly
improved by the use of a formalism. However, there remains an open issue: to
what extent can a development process based on a singular formal notation and
method succeed. The majority of approaches demonstrate a low level of
flexibility by attempting to use a single notation to express all of the
different aspects encountered in software development. Often, these approaches
leave a number of scalability issues open. We prefer a more eclectic approach.
In our experience, the use of a formalism-based toolkit with adequate notations
for each development phase is a viable solution. Following this principle, any
specific notation is used only where and when it is really suitable and not
necessarily over the entire software lifecycle. The approach explored in this
article is perhaps slowly emerging in practice - we hope to accelerate its
adoption. However, the major challenge is still finding the best way to
instantiate it for each specific application scenario. In this work, we
describe a development process and method for automotive applications which
consists of five phases. The process recognizes the need for having adequate
(and tailored) notations (Problem Frames, Requirements State Machine Language,
and Event-B) for each development phase as well as direct traceability between
the documents produced during each phase. This allows for a stepwise
verification/validation of the system under development. The ideas for the
formal development method have evolved over two significant case studies
carried out in the DEPLOY project
A Complete and Recursive Feature Theory
Various feature descriptions are being employed in logic programming
languages and constrained-based grammar formalisms. The common notational
primitive of these descriptions are functional attributes called features. The
descriptions considered in this paper are the possibly quantified first-order
formulae obtained from a signature of binary and unary predicates called
features and sorts, respectively. We establish a first-order theory FT by means
of three axiom schemes, show its completeness, and construct three elementarily
equivalent models. One of the models consists of so-called feature graphs, a
data structure common in computational linguistics. The other two models
consist of so-called feature trees, a record-like data structure generalizing
the trees corresponding to first-order terms. Our completeness proof exhibits a
terminating simplification system deciding validity and satisfiability of
possibly quantified feature descriptions.Comment: Short version appeared in the 1992 Annual Meeting of the Association
for Computational Linguistic
A strategy-based framework for assessing the flood resilience of cities – the Hamburg case study
Climate change and continuous urbanization contribute to an increased urban vulnerability towards flooding. Only relying on traditional flood control measures is recognized as inadequate, since the damage can be catastrophic if flood controls fail. The idea of a flood-resilient city – one which can withstand or adapt to a flood event without being harmed in its functionality – seems promising.
But what does resilience actually mean when it is applied to urban environments exposed to flood risk, and how can resilience be achieved? This paper presents a heuristic framework for assessing the flood resilience of cities, for scientists and policy-makers alike. It enriches the current literature on flood resilience by clarifying the meaning of its three key characteristics – robustness, adaptability and transformability – and identifying important components to implement resilience strategies. The resilience discussion moves a step forward, from predominantly defining resilience to generating insight into “doing” resilience in practice. The framework is illustrated with two case studies from Hamburg, showing that resilience, and particularly the underlying notions of adaptability and transformability, first and foremost require further capacity-building among public as well as private stakeholders. The case studies suggest that flood resilience is currently not enough motivation to move from traditional to more resilient flood protection schemes in practice; rather, it needs to be integrated into a bigger urban agenda
Technologieintensive Dienstleister: Neue Gründungswelle in der Branche
Unternehmensgründungen in technologieund wissensintensiven Branchen gewinnen weiter an Bedeutung für die Gründungsdynamik in Deutschland. Ihr Anteil an allen Gründungen hat 1999 gegenüber dem Vorjahr um zwei Prozentpunkte auf 15% zugenommen. Insbesondere die Zahl der Gründungen bei Telekommunikationsund EDV-Dienstleistern ist deutlich gestiegen. Technologie- und wissensintensive Unternehmensgründungen leisten daher einen bedeutenden Beitrag zum Strukturwandel hin zu einer wissensintensiven Unternehmensstruktur
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