Uncertainty and the design of building subsystems—A dynamic programming approach

This paper discusses the general problem of designing building subsystems which include probabilistic demands thus producing a stochastic problem. This class of problem, if linear, can be readily solved using classical stochastic linear programming. It is shown that the problem may be formulated as a stochastic dynamic program. A problem of designing the HVAC subsystem is formulated and solved as a dynamic program. Comparisons are made between the two methods. It is shown that dynamic programming is the more powerful method both in terms of obtaining the solution and in its post-optimality analysis. It is suggested that dynamic programming is a suitable technique for a wide range of building and architectural design problems.     

A genetic engineering approach to genetic algorithms

We present an extension to the standard genetic algorithm (GA), which is based on concepts of genetic engineering. The motivation is to discover useful and harmful genetic materials and then execute an evolutionary process in such a way that the population becomes increasingly composed of useful genetic material and increasingly free of the harmful genetic material. Compared to the standard GA, it provides some computational advantages as well as a tool for automatic generation of hierarchical genetic representations specifically tailored to suit certain classes of problems.     

Holonic transport scheduling with teletruck

TELETRUCK is a multiagent-based dispatch support system developed in close collaboration with forwarders and transport engineers. The system supports dispatch officers in route planning, fleet management, and driver scheduling. TELETRUCK allows for dynamic planning and online optimization of transport orders based on an integration with modern telecommunication facilities. The TELETRUCK approach uses holonic agents, i.e., agents composed of subagents that act in a corporated way, in order to achieve a flexible, structured resource management in the planning process. A brief overview is given of the current implementation status of the TELETRUCK application prototype. Communication, coordination, and resource control distinguishing holonic from common multiagent systems are discussed. The underlying algorithms and protocols are described. Future extensions of the approach for intermodal and intercompany transport planning are discussed aiming at a smooth integration of modern transport and telecommunication networks.     

Study of carbon erosion under ion bombardment at high temperature: Application to the thermal protection system of Solar Probe+

Solar Probe+ (SP+) will employ a combination of in situ measurements and imaging to achieve the mission’s primary scientific goal: to understand how the Sun’s corona is heated and how the solar wind is accelerated. The Solar Probe+ thermal protection system (TPS) can be a carbon-carbon (C-C) composite shield, reaching temperatures of 1600-2100 K and submitted to radiation effects including physical sputtering, chemical erosion, sublimation and radiation-enhanced sublimation (RES). In this study, different numerical codes were used to describe the behaviour of a carbon-based thermal protection system. The physical sputtering yield of carbon by hydrogen and helium ions is less than 2%. The maximum implantation yield of ions is more than 85% and the implantation depth is around 100 nm for hydrogen and 150 nm for helium. This could have a great influence on the material properties and its chemical erosion, characterized by the production of hydrocarbons (acetylene and methane) and consequently the degradation of the composite and the pollution of the measurement of the onboard instruments. Finally, an experimental study is also done on polycrystalline graphite to observe the various erosion mechanisms of the material under extreme conditions.     

Forense Chemie

Ohne Zusammenfassung     

Referate

Ohne Zusammenfassung     

Unexpected discoveries and S-invention of design requirements: important vehicles for a design process

Designers, during a conceptual design process, do not just synthesize solutions that satisfy initially given requirements, but also invent design issues or requirements that capture important aspects of the given problem. How do they do this? What becomes the impetus for the invention of important issues or requirements? So-called ‘unexpected discoveries', the acts of attending to visuo-spatial features in sketches which were not intended when they were drawn, are believed to contribute to it. The purpose of the present research is to verify this hypothesis. Analysing the cognitive processes of a practising architect in a design session, we found that in about a half of his entire design process there were bi-directional relations between unexpected discoveries and the invention of issues or requirements. Not only did unexpected discoveries become the driving force for the invention of issues or requirements, but also the occurrence of invention, in turn, tended to cause new unexpected discoveries. This has provided empirical evidence for two anecdotal views of designing. First, designing is a situated act; designers invent design issues or requirements in a way situated in the environment in which they design. We call inventions of this sort situated-invention (S-invention). Secondly, a design process progresses in such a way that the problem-space and the solution-space co-evolve. Further, this has brought a pedagogical implication as well as an insight about an important aspect of learning by experience in design.     

Referate

Ohne ZusammenfassungIn die Zusammenstellung der Referate sind auch die Originalmitteilungen nochmals aufgenommen und durch Kursiv-Typen der Seitenzahlen kenntlich gemacht.     

Milch und K?se

Ohne Zusammenfassung