A Simulation Framework for Heterogeneous Agents

We introduce a generic simulation framework suitable for agent-based simulations featuring the support of heterogeneous agents, hierarchical scheduling, and flexible specification of design parameters. One key aspect of this framework is the design specification: we use a format based on the Extendible Markup Language (XML) that is simple-structured yet still enables the design of flexible models. Another issue in agent-based simulations, especially when ready-made components are used, is the heterogeneity arising from both the agents' implementations and the underlying platforms. To tackle such obstacles, we introduce a wrapper technique for mapping the functionality of agents living in an interpreter-based environment to a standardized JAVA interface, thus facilitating the task for any control mechanism (like a simulation manager) because it has to handle only one set of commands for all agents involved. Again, this mapping is made by an XML-based definition format. We demonstrate the technique by applying it to a simple sample simulation of two mass marketing firms operating in an artificial consumer environment.     

Integrating skills into multi-agent systems

Currently, an important topic of robotic research is the design and development of multi-agent robot systems (MASs). In these a number of autonomous robots cooperate and coordinate themselves in order to pursue given goals. The agents of an MAS not only have to work autonomously or in cooperation with other agents, but in dynamic, relatively unstructured environments. Therefore, the agents require agent-specific but flexible skills to cope with their tasks and the environment's variability. On the other hand, the actions to be performed by agents in an MAS have to meet certain requirements imposed by the MAS's structure. The representation of actions has to support planning, inter-agent communication, task negotiation etc. In this paper, we describe a method of combining the agent-specific nature of skills with the requirements for a general action knowledge representation inherent to MASs, by presenting elementary operations (EOs) that provide an appropriate interface.     

Influence of Powder Morphology and Chemical Composition on Metallic Foams produced by SlipReactionFoamSintering (SRFS)‐ Process

The SlipReactionFoamSintering (SRFS)‐ process is a metallurgical method to produce open‐cell metallic foams of iron based materials, steels and nickel based materials. In this process several chemical reactions take place. Through the most influential parameter, the morphology of the metallic powder, different properties of the foam can be adjusted, such as the viscosity of the slip, the cell structure and the mechanical properties. Several examples are presented in this paper. Moreover, the thermal conductivity of three foams is measured with the transient‐heat‐source‐technique.     

„Medizinische Notwendigkeit“: Herausforderungen eines unscharfen Begriffs

Definition of the problem

“Medical necessity” (MedN) is the central regulatory concept for decisions about which services are covered by German statutory health insurance. Despite its seeming objectivity and dependence on physicians’ expert judgment, the concept is by no means clearly defined.

Arguments

In this first of five planned papers on the conceptual analysis of MedN from the perspectives of philosophy and ethics of medicine, law, and (social) medicine, the focus lies on systemizing ongoing controversies.

Conclusion

Our goal is to come up with a so far missing foundation for detailed debates. We aim to clarify MedN’s conceptual structure, function, contextuality, and ambiguities as well as the fundamental limits of conceptual investigations for the normative questions at issue of regulating medical services.

     

Preference-inconsistent recommendations: An effective approach for reducing confirmation bias and stimulating divergent thinking?

The Web is a perfect backdrop for opinion formation as a multitude of different opinions is publicly available. However, the different opinions often remain unexploited: Learners prefer preference-consistent over preference-inconsistent information, a phenomenon called confirmation bias. Two experiments were designed to test whether technologies such as recommender systems can be used to overcome this bias. The role of preference-inconsistent recommendations was explored by comparing their influence to a condition with preference-consistent recommendations and to a control condition without recommendations. In Study 1, preference-inconsistent recommendations led to a reduction of confirmation bias and to a more moderate view of the controversial topic of neuro-enhancement. In Study 2, we found that preference-inconsistent recommendations stimulated balanced recall and divergent thinking. Together these studies showed that preference-inconsistent recommendations are an effective approach for reducing confirmation bias and stimulating divergent thinking. In conclusion, future research and practical implications are discussed.     

Study of Lewis acid catalyzed chemical bromination and bromoalkylation of multi-walled carbon nanotubes

Chemical functionalization of carbon nanotubes (CNT) with nucleophiles requires introduction of electrophilic reactive sites on the CNTs. This can, for instance, be accomplished by the chemical bromination procedure with elemental bromine and a set of Lewis acids (BBr₃, BF₃ × Et₂O, AlBr₃, FeBr₃, ZnBr₂, TiBr₄, SiBr₄, SnBr₄, VBr₃) or a radical starter like dibenzoylperoxide (DBPO) in appropriate solvents at varied temperature. The present approach to electrophilic sites relies on the well-known electrophilic aromatic substitution or addition of bromine with aromatic structural units. In addition to the use of bromine, the introduction of haloalkyl groups was also investigated here using bis-electrophiles or haloalcohols and Brønsted acids. The advantages and drawbacks of the studied reaction conditions, the obtained degree of bromination as analyzed by X-ray photoelectron spectroscopy (XPS) and the amount of introduced bromine that can be substituted by a nucleophile are presented and discussed.     

Assessment of physical strain in younger and older subjects using heart rate and scalings of perceived exertion

Physical strain is usually evaluated physiologically by using the heart rate (HR) or psychologically using scaled perceived exertion (PE). In order to explore the relationship between these approaches, we compared the series of both measurements taken simultaneously during work on a bicycle ergometer. A total of 29 participants aged between 27 and 41, 42 and 56, and 57 and 71 years took part in 28 minutes of cycling with systematically increased and decreased load as well as in 7 hours of continuous cycling with low to medium exertion, interrupted by brief peak loads at high to very high exertion levels. Results revealed that, while both measurements are suitable to capture physical strain, HR is not as specific as PE. The older participants further perceived comparable physical loads as more demanding as the younger participants. With an aging workforce, results have potential implications for the organisation of work places.