KNOWLEDGE ACQUISITION AND EXPERTISE EVALUATION*

The knowledge acquisition phase of knowledge engineering is related to the phenomenology of domain expertise. The relationship between knowledge extraction and meta-knowledge (knowledge about what we know and how we reason) is stressed. Two knowledge extraction techniques for hard-to-trace expert reasoning are introduced. The nature of geographical knowledge and expertise is examined and related to the process of building spatial theory.     

Wärmestrom,Massenstrom und Volumstrom

Zusammenfassung Ausgehend von der Gleichung eines mit einem Massenstromm=v mitgeführten WärmestromesL=m i wird gezeigt, daß der Wärmestrom nur dann willkürfrei angegeben werden kann, wenn der Massenstrom im Mittel verschwindet, da die spezifische Enthalpiei nur bis auf eine Konstante bestimmt ist. Auch bei abgeglichenem Massenstromm=0 herrscht eine dem mittleren Austauschwärmestrom proportionale mittlere Windgeschwindigkeitv senkrecht zur Zählfläche, wobei in der Luftv/L=2 mm sec^–1/cal cm^–2 min^–1 ist.

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Summary Proceeding from the equation of a heat fluxL=m i carried along by a mass fluxm=v, it is shown that the heat flux can only be given without arbitrary assumptions, if the mass flux disappears in the mean, since the specific enthalpyi is determined only up to a constant. Also for a balanced mass fluxm=0 there exists an average wind velocityv normal to the surface of reference, which is proportional to the mean heat exchange flux, whereby for airv/L=2 mm sec^–1/cal cm^–2 min^–1.

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Résumé Partant de l'équation d'un flux de chaleurL=m i entraîné dans un courant de massem=v, on montre qu'il ne peut être dêterminé sans arbitraire que lorsque le courant de masse disparaît en moyenne, puisque l'enthalpiei spécifique n'est déterminée qu'à une constante près. Même par courant de massem=0 neutralisé, il existe une vitesse moyenne de ventv normale à la surface envisagée, proportionnelle au flux moyen d'échange turbulent de chaleur, avecv/L=2 mm sec^–1/cal cm^–2 min^–1 dans l'air.

     

Zur Darstellung der spektralen Verteilung der Strahlungsenergie

Zusammenfassung Durch passende Umformung und Darstellung desPlanckschen Strahlungsgesetzes wird eine anschauliche Rechtfertigung für die in der Meteorologie übliche Trennung der Strahlungsströme in kurz- und langwellige versucht. Es zeigt sich, daß die Trennung zwischen 2 und 7 gemacht werden muß, da in diesem Bereich relativ wenig meteorologisch bedeutsame Strahlung vorkommt.

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Summary An attempt is made to justify, by conveniently transforming and representingPlancks radiation law, the separation of radiation into a short-wave and a long-ware flux as is usual in meteorology. It is shown that the separation must be made between 2 and 7 in this range occurring only relatively few radiation of meteorological importance.

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Résumé Par une transformation convenable de la loi de rayonnement dePlanck, l'auteur tente de justifier la distinction faite en météorologie entre le rayonnement à courte et à longue longueur d'onde. Il constate que la séparation doit se faire entre 2 et 7 , puisque dans cet intervalle le rayonnement n'a que peu d'importance du point de vue météorologique.

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Mit 4 Textabbildungen.     

Untersuchungen am zugefrorenen Bodensee

Zusammenfassung Für den Winter 1962/63 wird ein überblick über den Gang der Luft- und Wassertemperaturen für den Bodensee, den Beginn und den Verlauf der inversen Temperaturschichtung sowie über Ergebnisse von Eisbeobachtungen gegeben. Die Richtungen der im ?stlichen Obersee beobachteten Str?mungen werden mit ?lteren Ergebnissen verglichen. Als Ursache der Entstehung von Str?mungen wird die Windbewegung angesehen. Die Ergebnisse von Messungen des Sauerstoffgehaltes und des Phosphatgehaltes bewiesen neben der bestehenden thermischen auch eine qualitative Schichtung des Wasserk?rpers. Staatliches Institut für Seenforschung und Seenbewirtschaftung, Langenargen am Bodensee (Direktion: Dr. W. Nümahn) Für Hilfe bei den Messungen und für die überlassung verschiedener Werte aus seiner noch nicht ver?ffentlichten Dissertation danke ich HerrnW. Brettschneider, Geographisches Institut der Universit?t Bonn, Abt. Klimatologie und Hydrologie. Ferner unterstützten mich Herr Regierungs-OberbauinspektorHerr, Eismeister in Konstanz, mit Daten aus seinen Eisbeobachtungen, Herr DiplommeteorologeWaibel, Wetterwarte Friedrichshafen, mit Daten aus Messungen der Windst?rke, der Windrichtung und der Tagestemperaturen, sowie das Eidgen?ssische Amt für Wasserwirtschaft in Bern mit Abflussdaten des Rheins.     

Gay men, leisure space and South African cities: the case of Cape Town

In response to the current paucity of geographical research into post-apartheid development of gay leisure space, the paper focuses on the nature and extent of gay leisure space development in De Waterkant, South Africa’s first “gay village”, located in the Cape Town CBD periphery. Despite a new liberal constitutional environment, the gay spaces generated in post-apartheid De Waterkant are not inclusive of most gay South Africans. On the contrary, the legacy of apartheid race, gender and class inequality persists, generating a wealthy, White, male leisure space enclave. As a consequence, De Waterkant’s potential to function as a site of identity formation, development and re-affirmation, seen in many gay villages found in other Western societies, appears unlikely.     

South East Europe electricity roadmap – modelling energy transition in the electricity sectors

One of the most important challenges for the South East Europe region will be replacing more than 30% of its presently installed fossil fuel generation capacity by the end of 2030, and more than 95% by 2050 if its age structure is considered. This requires a strong policy framework to incentivise new investments in a region currently lacking investors, but also presents an opportunity to shape the electricity sector over the long term according to the broader energy transition strategy of the EU and the Energy Community. The aim of this paper is to assess what type of long-term pathways exist for electricity sector development in the region if they follow the energy transition process of the EU. In this model-based scenario assessment, long term electricity sector futures are explored using a set of interlinked electricity models evaluating the level of renewable energy investment required in the region to reach a deep decarbonization target, assuming emission reduction above 94% by 2050 compared to 1990 in line with the long term market integration and climate policy goals of the EU. It also explores what are the most important system wide impacts of the high deployment of renewable energy concerning generation adequacy and security of supply.

Key policy insights

• Energy policies in the South East Europe (SEE) region, both at the national and regional level, should focus on enabling renewable energy integration, as this will be a key component of the future energy mix.

• EU and Energy Community policies should be incorporated into national energy planning to ensure that SEE countries embark on the energy transition process at an early stage.

• Stranded costs should be carefully considered in decision-making on new fossil-fuel generation and gas network investment in order to avoid lock-in to carbon intensive technologies.

• If consistent decarbonization policy prevails, with a significant and persistent CO2 price signal, the role of natural gas remains transitory in the region.

• The SEE region offers relatively cheap decarbonization options: the power sector can reduce GHG emissions above 94% by 2050 in the modelled scenarios.

     

A post-IR IRSL chronology and dust mass accumulation rates of the Nosak loess-palaeosol sequence in northeastern Serbia

In the Middle Danube Basin, Quaternary deposits are widely distributed in the Vojvodina region where they cover about 95% of the area. Major research during the last two decades has been focused on loess deposits in the Vojvodina region. During this period, loess in the Vojvodina region has become one of the most important Pleistocene European continental climatic and environmental records. Here we present the dating results of 15 samples taken from the Nosak loess-palaeosol sequence in northeastern Serbia in order to establish a chronology over the last three glacial–interglacial cycles. We use the pIRIR₂₉₀ signal of the 4–11 μm polymineral grains. The calculated ages are within the error limits partially consistent with the proposed multi-millennial chronostratigraphy for Serbian loess. The average mass accumulation rate for the last three glacial–interglacial cycles is 265 g m⁻² a⁻¹, which is in agreement with the values of most sites in the Carpathian Basin. Our results indicate a highly variable deposition rate of loess, especially during the MIS 3 and MIS 6 stages, which is contrary to most studies conducted in Serbia where linear sedimentation rates were assumed.