Die Reifegradmodellierung ist ein in Praxis und Wissenschaft anerkanntes Instrument, das in jüngster auch Zeit im Zusammenhang mit nachhaltiger IKT diskutiert wird. Parallel dazu ist der Durchdringungsgrad betrieblicher Umweltinformationssysteme im betrieblichen Alltag überschaubar, die BUI bleibt nach wie vor mit verschiedenen Problemen konfrontiert. Daher soll der Versuch unternommen werden, über die Entwicklung eines Reifegradmodells für das IT-gestützte Umweltmanagement die Anreize für Unternehmen zu erhöhen und so BUIS vermehrt zum Einsatz zu bringen. Ziel dabei ist es, das Umweltmanagement langfristig von einem eher passiven, wenig integrierten und oftmals als kostspielig angesehenen Status hin zu einem strategischen Instrument zu entwickeln, dessen Potential mit Hilfe des Reifegradmodells systematisiert ausgeschöpft werden kann. Die Entwicklung von Reifegradmodellen wird mit Hilfe eines Vorgehensmodells skizziert. Da die Entwicklung eines Reifegradmodells für das Umweltmanagement im Allgemeinen ein sehr umfangreiches Unterfangen darstellt, wird im Anschluss daran die Anwendung zunächst auf den konkreten Fall des Energiemanagements beschränkt und die geplante Umsetzung innerhalb eines Unternehmensnetzwerks skizziert.

The increasingly use of wireless networks and mobile technologies has raised the desire not only to have a good quality access to the network, but also to seamlessly change the network when moving. Various handover algorithmus have been proposed to handle this situation. Unfortunately, many of these algorithms have been only evaluated in simulative environments using simplified models and network assumptions. They do not take the wide range of mobile devices with varying system parameters and capabilities into account which are offered on the market. For the practical deployment, handover algorithms are required which adapt to various device parameters and network characteristics. In this paper we present a fuzzy-based vertical handover decision algorithm which adjusts itself to the given device parameters and network capabilities. Starting with a discussion on the requirements to vertical handover, we present the algorithm and describe how it is activated during the various phases of the handover process. Thereafter we present several experiments which evaluate the accuracy of the handover decision, the quality of service guarantees for the application, and the resource consumption.

Maturity assessment modelling is a recognised instrument in both academic and business domains which has recently become the focus of discussion in connection with sustainable information and communication technology. At the same time, the acceptance of Corporate Environmental Information Systems (CEMIS) in the corporate world remains modest, and CEMIS continue to be confronted with various problems. Against this background, a maturity assessment model for IT-supported environmental management will be developed with the aim of incentivising companies to deploy CEMIS and thus increase its usage in the corporate domain. The long-term goal is to fundamentally shift the status of environmental management so that it is no longer viewed as being passive, non-integrated and often costly, but rather as being a strategic instrument whose potential can be systematically exploited with the help of a maturity assessment model. The development of maturity assessment models will first be illustrated with the help of a process model. As the development of a maturity assessment model for environmental management in general represents an extremely comprehensive undertaking, application of the model developed here will be explored in the limited context of energy management and planned implementation within a corporate network.

The increasing use of wireless networks has raised the desire to have not only a stable and good quality access to the network, but also to seamlessly change the network when moving. Various handover algorithms have been proposed to handle this situation. Unfortunately, many of these handover algorithms have only been evaluated by simulations. They do not take the wide range of mobile devices with varying system parameters into account. For the practical deployment, handover algorithms are required that adapt to various device parameters and network characteristics. In this paper we present a fuzzy-based vertical handover decision algorithm which adjusts itself to the given device and network capabilities. Starting with a discussion of handover requirements we present the algorithm and describe how it is activated in the handover process. Finally we present several experiments which evaluate the accuracy of the handover decision, the quality of service guarantees for the application, and the resource consumption.

Monomorphic lemurs of Madagascar allow us to investigate whether there are behavioural mechanisms that compensate for sex-specific differences in the costs of maintenance and reproduction in arboreal primates. Food selection of the pair-living Lepilemur ruficaudatus was studied in relation to food chemistry, and travel distances were measured as possible indications of differential investment in ranging activities (possibly related to the defence of territories and/or mating opportunities). Fourteen females and 14 males were radio-tracked for a total of 365 half-nights (from dusk to midnight or from midnight to dawn) at different times of the year (birth, lactation and weaning, pre-mating, post-mating). When based on monthly means, the two sexes did not differ in nightly travel distances. Food selection of females and males did not differ in relation to the chemical composition of leaves, but fruits consumed by females had lower fibre contents than fruits consumed by males. Even though other behavioural data are fragmentary, little evidence exists for behavioural mechanisms in L. ruficaudatus to compensate for the different energetic costs of females and males.

We characterize the spatial organization of red-tailed sportive lemurs ( Lepilemur ruficaudatus ) as a key aspect of their social organization and social system. Sportive lemurs are small (<1000 g), nocturnal and folivorous primates endemic to Madagascar. We studied a population of 57 individually-marked individuals in Kirindy Forest, western Madagascar, between 1995 and 2001. We radio-tracked 20 males and 26 females of the marked population to obtain detailed information on the size and location of their home ranges. Census data and morphometric measurements provided complementary data sets. Males and females occupied small (<1 ha) home-ranges. Long-term records from 9 individuals revealed home-range stability over several years. In 4 cases home ranges overlapped extensively with that of one member of the opposite sex; in 2 cases, a spatial association of 1 male and 2 females occurred. However, home ranges overlapped very little with neighboring individuals of both sexes. During the study period, spatially associated individuals used on average 5.6 sleeping trees within 117 days, but they spent on average only about every fourth night together. The data suggest that home ranges in red-tailed sportive lemurs are exclusively used by pairs or trios and that the modal social organization of red-tailed sportive lemurs is pair-living.