Contributions in Merlin

Designing software architectures that exhibit a good trade-off between multiple quality attributes is hard. Even with a given functional design, many degrees of freedom in the software architecture (e.g. component deployment or server configuration) span a large design space. In current practice, software architects try to find good solutions manually, which is time-consuming, can be error-prone and can lead to suboptimal designs.We propose an automated approach guided by architectural tactics to search the design space for good solutions. Our approach applies multi-objective evolutionary optimization to software architectures modelled with the Palladio Component Model. Software architects can then make well-informed trade-off decisions and choose the best architecture for their situation.To validate our approach, we applied it to the architecture models of two systems, a business reporting system and an industrial control system from ABB. The approach was able to find meaningful trade-offs leading to significant performance improvements or costs savings. The novel use of tactics decreased the time needed to find good solutions by up to 80\%.

This study aims to explore a control architecture that enables the control of a soft and flexible octopus-like arm for an object reaching task. Inspired by the division of functionality between the central and peripheral nervous systems of a real octopus, we discuss that the important factor of the control is not to regulate the arm muscles one by one but rather to control them globally with appropriate timing, and we propose an architecture equipped with a recurrent neural network (RNN). By setting the task environment for the reaching behavior, and training the network with an incremental learning strategy, we evaluate whether the network is then able to achieve the reaching behavior or not. As a result, we show that the RNN can successfully achieve the reaching behavior, exploiting the physical dynamics of the arm due to the timing based control.

Several countries have implemented bonus taxes for corporate executives in response to the financial crisis of 2007-2010. Using a principal-agent model, this paper analyzes how bonus taxes affect the agent's effort, compensation package, tax revenue and social welfare. We show that, contrary to its intention, a bonus tax may even increase the bonus rate and decrease the fixed salary. In addition, a bonus tax can induce the principal to pay higher bonuses even though the agent's effort always decreases. Finally, a bonus tax decreases social welfare unless the social planner places a sufficiently high weight on tax revenue.

Nowadays, even with the existence of many Cloud Providers (CP) in the market, it is still impossible to see CPs who guarantee, or at least offer, an SLA specification to Cloud Users (CU) interests: not just offering percentage of availability, but also guaranteeing specific performance parameters for a certain Cloud application. Due to (I) the huge size of CPs' IT infrastructures and (2) the high complexity with multiple inter-dependencies of resources (physical or virtual), the estimation of specific SLA parameters to compose Service Level Objectives (SLOs) with trustful Key Performance Indicators (KPis) tends to be inaccurate. This paper proposes the initial design and preliminary approach tor an SLA Support System for CC (SLACC) in order to estimate in a formalized methodology - based on available CC infrastructure parameters - what CPs will be able to offer/accept as SLOs or KP!s and, as a consequence, which increasing levels ofSLA specificity for their customers can be reached.

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The concept of value co-creation and its notion of the customer as co-creator of value have gained much academic interest, notably in marketing and operations research. While several competing perspectives have been conceptually discussed in literature, research on the practical implications of value co-creation is scarce. Using the example of sales-oriented advisory, we show gaps between existing co-creation concepts and current practice in five problem areas. We develop four general solution perspectives on the advisor-client encounter as guidelines to overcome these gaps and discuss design requirements of their technological instantiations in advisory support systems. We present exemplary implementations of such systems in two domains: travel counseling and financial advisory. Revealing the practical implications of value co-creation on advisory encounters, these examples also demonstrate that the solution perspectives have to be implemented quite differently for individual domains.