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101.
The research field “Modeling business information systems” has a long tradition in the scientific discipline of Business and Information Systems Engineering (BISE). The present paper highlights research shaping the research field, discusses challenges impairing the development of the research field in the coming years, and outlines elements of a future research agenda.  相似文献   
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The main objective of the European Water Framework Directive (WFD) is the achievement of a good ecological and chemical status of the water environment (water bodies). This status corresponds to the limit value of Germany's Working Group of the Federal States on Water Problems Issues (LAWA) for water quality class II (3 mg/l total nitrogen). The rivers in the intensively cropped Upper Ems River basin (northwestern Germany) show total nitrogen concentrations in excess of 5–10 mg/l. Hence, the objective of our study was to find a land use and land management scenario that would reduce the total nitrogen concentration to meet the WFD requirements for good ecological and chemical status. We developed consecutive land use and management scenarios on the basis of policy instruments such as the support of agro-environmental measures by Common Agricultural Policy and regional landscape development programs. The model simulations were done by using the Soil and Water Assessment Tool (SWAT). Results of SWAT scenario calculations showed that drastic measures, which are unrealistic from a socio-economic point of view, would be needed to achieve the water quality target in the basin (reduction of arable land from 77.2% to 46% [13% organic farming], increase of pasture from 4% to 15%, afforestation from 10% to 21%, increase of protected wetlands from 0% to 9%, etc.). The example shows additionally that the achievement of the WFD targets is only possible with a consideration of regional landscape and land use distinctions. A related problem yet to be addressed is the general lack of measured water quality data with which to calibrate and validate water quality models such as SWAT. This adds considerable uncertainty to already complicated and uncertainty situations. Thus, improved strategies for water quality monitoring, and data accessibility must be established.  相似文献   
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The existence of a shared understanding about a collaborative work process among all involved actors is one prerequisite for its successful implementation. The development of a shared understanding is facilitated when the actors make explicit their individual views and create externalizations that can be used as subjects of discourse. Instruments supporting externalization and discourse about collaborative work need to provide adequate forms of representation and guide actors in implementing these reflection and alignment processes. Appropriate guidance can facilitate the construction of a shared understanding for actors not accustomed to such processes. This paper introduces a methodology that offers structural and procedural guidance by adopting diagrammatical conceptual modeling techniques. This methodology has been evaluated extensively in a multiple case study. A combination of interaction analysis of the modeling process and ex-post assessment of the actors’ perceptions has been used to evaluate the adequacy of the proposed methodology with respect to the pursued objectives. The results confirm that the modeling methodology and the proposed guidance measures appropriately support the process of constructing a shared understanding about collaborative work processes.  相似文献   
107.
Empirical Evaluation of Fair Use Flat Rate Strategies for Mobile Internet   总被引:1,自引:1,他引:1  
The fair use flat rate is a promising tariff concept for the mobile telecommunication industry. Similar to classical flat rates it allows unlimited usage at a fixed monthly fee. Contrary to classical flat rates it limits the access speed once a certain usage threshold is exceeded. Due to the current global roll-out of the LTE (Long Term Evolution) technology and the related economic changes for telecommunication providers, the application of fair use flat rates needs a reassessment. We therefore propose a simulation model to evaluate different pricing strategies and their contribution margin impact. The key input element of the model is provided by so-called discrete choice experiments that allow the estimation of customer preferences.  相似文献   
108.
Saving Accounts versus Stocks and Bonds in Household Portfolio Allocation   总被引:1,自引:0,他引:1  
We study the structure of household portfolios of financial wealth by analyzing both the determinants of total financial wealth and the choice between risky (stocks and bonds) and riskfree assets (saving accounts). The econometric specification is a generalized trivariate Tobit model, estimated on a cross section of 3,077 households in the Netherlands in 1988. We account for endogeneity of financial wealth and for selectivity due to nonreporting. Results show that the level of financial wealth and the marginal tax rate are major determinants of the allocation between riskfree and risky assets.  相似文献   
109.
This paper is based on the traditional Austrian Theory of Capital which deals with expected values of future returns of investments over various periods of time. The longer the time period that elapses between the beginning of a production process and its end, the higher the (expected) productivity must be due to positive time preferences of individuals. This paper focuses on the uncertainty of future returns and on uncertainty preferences, instead. Based on the Hayekian idea of the dispersion of knowledge in society, it will be shown that there is a systematic relationship between the structure of capital and uncertainty. This result will be derived for a production process characterized by complete vertical integration and one which is not completely vertically integrated. The distinction between these two settings is crucial, if one accepts the distinction between an individual and a social period of production and the planning horizon which are introduced in this paper.  相似文献   
110.
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