Introducing modern agroforestry to students as the next generation of decision makers in ecosystem management

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Agroforestry in Germany : from traditional to modern applications

Paper presented at the 13th North American Agroforesty Conference, which was held June 19-21, 2013 in Charlottetown, Prince Edward Island, Canada.In Poppy, L., Kort, J., Schroeder, B., Pollock, T., and Soolanayakanahally, R., eds. Agroforestry: Innovations in Agriculture. Proceedings, 13th North American Agroforestry Conference, Charlottetown, Prince Edward Island, Canada, June 19-21, 2013.Agroforestry (AF) has a long history also in temperate climatic zones (e.g. grassland fruit orchards / "Streuobstwiesen" in southern Germany or wind brakes in northern Germany). However, due to the immense industrialization of the agricultural sector during the last decades those traditional land use systems were pushed to the fringes and were often not further promoted. On the other hand, modern agriculture also in most parts of Germany is progressively facing major ecological problems: i) loss of biodiversity, ii) soil erosion, and iii) eutrophication, including nitrate leaching. Furthermore, as all European member states should strive to a 20% share of renewable energy by 2020 (i.e., an equivalent of ca. 17.5 million ha of land dedicated to only produce energy crops), an additional pressure on farmland biodiversity as well as on soil and water resources can be expected. Within this context, information on most important and actual running AF activities in Germany, including contact addresses for further details are presented. All German_s AF activities were recently gathered in a newly formed AF working group (www.agroforst.org) to further promote AF on a national but also within the European AF association EURAF on the EU member state level (www.agroforestry.eu).Norbert P. Lamersdorf ; Soil Science of Temperate Ecosystems, Bu_sgen-Institute, University of G�ttingen, B�sgenweg 2, D-37077 G�ttingen, Germany

Context-Aware Computation Offloading for Mobile Cloud Computing: Requirements Analysis, Survey and Design Guideline

AbstractAlong with the rise of mobile handheld devices the resource demands of respective applications grow as well. However, mobile devices are still and will always be limited related to performance (e.g., computation, storage and battery life), context adaptation (e.g., intermittent connectivity, scalability and heterogeneity) and security aspects. A prominent solution to overcome these limita- tions is the so-called computation offloading, which is the focus of mobile cloud computing (MCC). However, current approaches fail to address the complexity that results from quickly and constantly changing context conditions in mobile user scenarios and hence developing effective and efficient MCC applications is still challenging. Therefore, this paper first presents a list of re- quirements for MCC applications together with a survey and classification of current solutions. Furthermore, it provides a design guideline for the selection of suitable concepts for different classes of common cloud-augmented mobile applications. Finally, it presents open issues that developers and researchers should be aware of when designing their MCC-approach

Context-based Cooperation in Mobile Business Environments – Managing the Distributed Execution of Mobile Processes

Realistic requirements of mobile business applications often exceed the capabilities of their respective local environments. In order to overcome such restrictions of specific mobile devices, services, and resources, this contribution introduces the concept of context-based cooperation. It is based on mobile processes which enable applications to cross boundaries of individual systems and thereby allow combining both mobile and stationary resources in order to realize highly dynamic individual applications. This contribution presents an approach for realizing context-based cooperation built upon on a respective context management infrastructure and execution environment. It also identifies specific requirements and proposes related enhancements for mobile business applications

A Reputation-Based Approach to Self-Adaptive Service Selection

Service-orientation provides concepts and tools for flexible composition and management of largescale distributed software applications. The automated run-time management of such loosely coupled software systems, however, poses still major challenges and is therefore an active research area, including the use of novel computing paradigms. In this context, the dynamic and adaptive selection of best possible service providers is an important task, which can be addressed by an appropriate middleware layer that allows considering different service quality aspects when managing the adaptive execution of distributed service workflows dynamically. In such an approach, service consumers are enabled to delegate the adaptive selection of service providers at run-time to the execution infrastructure. The selection criteria used are based on the cost of a service provision and the continuous, dynamic evaluation of reputations of providers, i.e. maintained track records of meeting the respective service commitments. This paper discusses the design and operating principle of such an automatic service selection middleware extension. Its ability to balance different quality criteria for service selection, such as service cost vs. the reliability of provision, is empirically evaluated based on a multi-agent platform approach