Make No Big Plans

In the face of ‘derivative architecture’, artificial commercial speculation that was a feature of the previous economic boom, Michelle Provoost and Wouter Vanstiphout of Crimson Architectural Historians call for a new understanding of the real city and its actual needs, basing interventions on observations rooted in society and spatial structures.     

Succinctness of regular expressions with interleaving,intersection and counting

In this paper, we study the succinctness of regular expressions (REs) extended with interleaving, intersection and counting operators. We show that in a translation from REs with interleaving to standard regular expressions a double exponential size increase cannot be avoided. We also consider the complexity of translations to finite automata. We give a tight exponential lower bound on the translation of REs with intersection to NFAs, and, for each of the three classes of REs, we show that in a translation to a DFA a double exponential size increase cannot be avoided. Together with known results, this gives a complete picture of the complexity of translating REs extended with interleaving, intersection or counting into (standard) regular expressions, NFAs, and DFAs.     

Solving the mobile mapping van problem: A hybrid metaheuristic for capacitated arc routing with soft time windows

Creating digital maps often requires driving around the streets in a so-called “mapping van”. Tele Atlas, the world leading supplier of maps and map data, uses a fleet of such vehicles to take pictures of streets and road signs. Minimising the number of days that a vehicle needs to traverse all streets in a given region gives rise to a capacitated arc routing problem. A specific characteristic of this problem, however, is the fact that taking pictures in the direction of the sun should be avoided as much as possible. This requirement adds soft time windows to the problem.In this paper we solve the mobile mapping van problem by transforming it into a vehicle routing problem with soft time windows. We then apply a hybrid metaheuristic, consisting of a local search phase to decrease the number of days and an iterated local search phase to minimise the time window violations. An exact linear programming solver is embedded to calculate the ideal starting time of the vehicle in each street.Our method is tested on academic and real-life problem instances and shown to be effective.     

Converter-connected distributed generation units with integrated harmonic voltage damping and harmonic current compensation function

The steadily growing share of converter-connected distributed generators, combined with a large amount of nonlinear and unbalanced loads connected to the electric power system, has led to a degraded power quality. Both harmonic voltage and harmonic current distortion may cause many unfavourable effects on the power system. However, the converter-connected distributed generators can be redesigned to have a positive effect on the distortion of the grid voltage. Two different approaches can be discerned. At the one hand, distributed generation units can be controlled to synthesize a resistive load for harmonic voltage components. This approach is called harmonic voltage damping. At the other hand, if the polluting current of an adjacent nonlinear load is measured and added to the control loop, the converter-connected distributed generator is able to compensate all harmonic current components of the nonlinear load. This approach is referred to as harmonic current compensation. In this paper, a control strategy for a converter-connected distributed generator is extended with a harmonic voltage damping function and a harmonic current compensation function. Experimental tests show that the voltage distortion of the grid voltage can be significantly improved.     

Guidelines for the Application of NAD(P)H Regenerating Glucose Dehydrogenase in Synthetic Processes

Glucose dehydrogenase (GDH) is frequently used for the reduction of NAD⁺ and NADP⁺ in bench‐ and industrial‐scale syntheses because the coenzyme regenerating system GDH is easy to apply, robust and relatively inexpensive. To optimize the application of this long known coenzyme regeneration system we investigated the commonly applied Bacillus GDH and characterized this enzyme by its kinetic features in the presence of substrates and products at pH 6.4 and 8.0. Three substrates/products were found to inhibit GDH considerably: (i) the reaction product glucono‐1,5‐lactone, (ii) the reduced coenzyme NAD(P)H and (iii) the oxidized coenzyme NAD(P)⁺. The inhibition of GDH under several process conditions was modeled using the determined kinetic constants. It was found that the GDH regeneration system is strongly inhibited by the usually applied conditions. This study provides the rate equation of the GDH reaction and simulations of this coenzyme regenerating system leading to an improved prediction and, thus, to a faster scale‐up and increased efficiency of NAD(P)H‐dependent synthetic processes.