We examine whether having previously been self-employed is a negative signal on the job market. In a UK field experiment where two applications of otherwise equally qualified individuals were sent out in response to the same vacancies in human resource management, we find that entrepreneurs systematically receive fewer responses than non-entrepreneurs. Empirical studies that treat market wages as the opportunity cost of remaining self-employed are therefore likely to overestimate alternative earnings to entrepreneurship.

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The paper details the research and corresponding implementation and testing steps of the FLEXOP demonstrator aircraft. Within the EU funded project an unmanned demonstrator aircraft is built to validate the mathematical modelling, flight control design and implementation side of active flutter mitigation. In order to validate the different methods and tools developed in this project, a flight test campaign is planned, in which the design and manufacturing of stiff wings (-0), are compared with very flexible wings (-1) with active flutter control, to see the overall benefit vs. risk of such technology. The mathematical models of the aircraft are first developed using FEM and CFD tools, what are later reduced by model order reduction techniques. The high-fidelity models are updated using Ground Vibration Test results. Manufacturing tolerances and variations in aircraft parameters are captured by systematic modelling of parametric and dynamic uncertainties. Both the simulation environment and the control design framework use different modelling fidelity, what are described within the paper. Reduced models are developed using two distinctive methods, respecting the control design needs: top-down balanced LPV reduction and bottom-up structure preserving methods. Based on the reduced order models various control design techniques have been elaborated by the consortium partners. In particular DLR developed and implemented a modal control method using H2 optimal blends for inputs and outputs. University of Bristol developed structured H-infinity optimal control methods, while SZTAKI proposed a worst-case gain optimal method structured controller synthesis method handling parametric and complex uncertainties. After the brief introduction of hardware-in-the-loop test setup and the description of mission scenarios the implementation issues of the baseline and flutter controllers are discussed. DLR and SZTAKI flutter controllers are evaluated in a hybrid software-/ hardware-in-the-loop test setup as at this stage of development the latter can not tolerate the estimated delay of the hardware system but their comparison is advantageous before future developments. Recommendations on active flutter mitigation methods are given based on the experience of synthesis and implementation of these controllers. Flight test results will follow these experiments, once the flight testing of the flutter wing commences.

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We examine sources of consistent regulatory decisions in a model where regulators respond to mixed incentives, including career concerns. In the reference case, regulators act as 'public servants' who strive to make the socially optimal decision, given limited information and the opportunity to observe the prior decision of another regulator. The addition of career concerns, such as a desire to avoid controversy or to implement a future employer's preferred policy, tends to reduce the degree of differentiation in sequentially taken decisions, hence increasing consistency. Therefore, it is possible to observe that the self-interested career concerns of regulators give rise to consistency in regulatory decision making. This type of consistency might lead to substantial deviations from optimal regulatory policies.

The idea of the EU funded FLEXOP project is to raise efficiency of a currently existing wing by derivative solution with higher aspect ratio at no excess structural weight. In order to enable such a resulting highly flexible wing the project goal is to develop methods for active suppression of flutter and passive load alleviation. The developed methods will be tested and validated with a UAV flutter demonstrator. The demonstrator is a 7m wingspan, 65kg MTOW UAV equipped with a jet engine. It features three different wing pairs. The first wing is a stiff design reference case, which is flown to get the baseline measurements for comparison. The second one is a wing designed very flexible specifically for active flutter control. The third wing is aeroelastically tailored for gust load alleviation. The paper describes the results of the aeroelastically tailored wing compared to the baseline reference wing.

Fixed-wing eVTOL UAV are unmanned aerial vehicles with electric powertrains capable of both hover and fast wing-borne forward flight. The high power consumption of the electric powertrains during vertical flight is in conflict with the usage of high energy density batteries. This study suggests dual battery architectures assembled from both high energy and high power battery types and with different complexity levels to overcome this problem. A modelling approach on the fidelity level of conceptual aircraft is presented. In an exemplary study with different aircraft types, the battery architectures' impact on aircraft performance is examined. With a single battery architecture as baseline, the results show improvements in endurance of 10 to 20% as a retrofit solution with current battery technology.

This paper describes the con¦guration selection process in the FP7 project ACFA (Active Control for Flexible Aircraft) 2020 in view of the Advisory Council for Aeronautics Research in Europe (ACARE) aims. The design process challenges and the comparison of a blended wing body (BWB) aircraft with a wide body carry-through wing box (CWB) con¦guration are described in detail. Furthermore, the interactions between the conceptual design and structural design using multidisciplinary design optimization (MDO) to rapidly generate and adapt structural models to design changes and provide early feedback of mass and center of gravity values for these nontraditional con¦gurations are discussed. Comparison of the two concepts determined that the developed all-lifting BWB airframe has the potential for a signi¦cant reduced fuel consumption compared to the CWB.