684 research outputs found
The pion form factor from first principles
We calculate the electromagnetic form factor of the pion in quenched lattice
QCD. The non-perturbatively improved Sheikoleslami-Wohlert lattice action is
used together with the improved current. We calculate form
factor for pion masses down to . We compare the mean square
radius for the pion extracted from our form factors to the value obtained from
the 'Bethe Salpeter amplitude'. Using (quenched) chiral perturbation theory, we
extrapolate our results towards the physical pion mass.Comment: 5 pages, 2 figures; proceedings of Hadron03, Aschaffenburg, German
Seaweed as feed supplement (OK-Net EcoFeed Practice Abstract)
• Effectivity might differ depending on the seaweed type, harvest season and processing method. Brown and red seaweed species may be better than green.
• Several commercial seaweed products can be used, and it is important to ask for documentation of effect before relying on e.g. effect on diarrhoea.
• High levels of macro and micro minerals have to be taken into account when composing diets with seaweed.
• Many seaweed extracts are available, which may not be suitable for organic production
Starfish as feedstuff (OK-Net Ecofeed Practice Abstract)
• Starfish should be harvested, at the earliest, three months before spawning to have highest protein and lowest ash content.
• High calcium levels limit the inclusion level of starfish meal in piglets’ diets to around 5%.
• Starfish meal is not organically certified but can still be used because it is not of agricultural origin.
• Starfish meal is already commercially available in Denmark.
• Diets can be optimized regarding amino acids and with lower crude protein
Marketing orientation and strategies in the Netherlands
This paper introduces a general, formal treatment of dynamic constraints, i.e., constraints on the state changes that are allowed in a given state space. Such dynamic constraints can be seen as representations of "real world" constraints in a managerial context. The notions of transition, reversible and irreversible transition, and transition relation will be introduced. The link with Kripke models (for modal logics) is also made explicit. Several (subtle) examples of dynamic constraints will be given. Some important classes of dynamic constraints in a database context will be identified, e.g. various forms of cumulativity, non-decreasing values, constraints on initial and final values, life cycles, changing life cycles, and transition and constant dependencies. Several properties of these dependencies will be treated. For instance, it turns out that functional dependencies can be considered as "degenerated" transition dependencies. Also, the distinction between primary keys and alternate keys is reexamined, from a dynamic point of view.
Evaluation of Cognitive Architectures for Cyber-Physical Production Systems
Cyber-physical production systems (CPPS) integrate physical and computational
resources due to increasingly available sensors and processing power. This
enables the usage of data, to create additional benefit, such as condition
monitoring or optimization. These capabilities can lead to cognition, such that
the system is able to adapt independently to changing circumstances by learning
from additional sensors information. Developing a reference architecture for
the design of CPPS and standardization of machines and software interfaces is
crucial to enable compatibility of data usage between different machine models
and vendors. This paper analysis existing reference architecture regarding
their cognitive abilities, based on requirements that are derived from three
different use cases. The results from the evaluation of the reference
architectures, which include two instances that stem from the field of
cognitive science, reveal a gap in the applicability of the architectures
regarding the generalizability and the level of abstraction. While reference
architectures from the field of automation are suitable to address use case
specific requirements, and do not address the general requirements, especially
w.r.t. adaptability, the examples from the field of cognitive science are well
usable to reach a high level of adaption and cognition. It is desirable to
merge advantages of both classes of architectures to address challenges in the
field of CPPS in Industrie 4.0
Mobilizing the Temporary Organization: The Governance Roles of Selection and Pricing
Many marketing transactions between buyers and suppliers involve short-term collaborations or so-called temporary organizations. Such organizations have considerable value-creation potential but also face challenges, as evidenced by their mixed performance records. One particular challenge involves relationship governance, and in this respect, temporary organizations represent a conundrum: On the one hand, they pose significant governance problems due to the need to manage numerous independent specialists under time constraints. On the other hand, temporary organizations lack the inherent governance properties of other organizational forms such as permanent organizations. The authors conduct an empirical study of 429 business-to-business construction projects designed to answer two specific questions: First, how are particular selection and pricing strategies deployed in response to monitoring and coordination problems? Second, does the joint alignment between the two mechanisms and their respective attributes help mitigate cost overruns? The authors follow a formal hypothesis test with a series of in-depth interviews to explore and to gain insight into the validity of the key constructs, explanatory mechanisms, and outcomes. Managerially, the authors answer the long-standing question of how to mobilize a temporary organization. Theoretically, they develop an augmented “discriminating alignment” heuristic for relationship management involving multiple governance mechanisms and attributes.acceptedVersio
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