Machine learning and robust MPC for frequency regulation with heat pumps

With the increased amount of volatile renewable energy sources connected to the electricity grid, there is an increased need for frequency regulation. On the demand side, frequency regulation services can be offered by buildings that are equipped with electric heating or cooling systems, by exploiting the thermal inertia of the building. Existing approaches for tapping into this potential typically rely on a first-principles building model, which in practice can be expensive to obtain and maintain. Here, we use the thermal inertia of a buffer storage instead, reducing the model of the building to a demand forecast. By combining a control scheme based on robust Model Predictive Control, with heating demand forecasting based on Artificial Neural Networks and online correction methods, we offer frequency regulation reserves and maintain user comfort with a system comprising a heat pump and a storage tank. We improve the exploitation of the small thermal capacity of buffer storage by using affine policies on uncertain variables. These are chosen optimally in advance, and modify the planned control sequence as the values of uncertain variables are discovered. In a three day experiment with a real multi-use building we show that the scheme is able to offer reserves and track a regulation signal while meeting the heating demand of the building. In additional numerical studies, we demonstrate that using affine policies significantly decreases the cost function and increases the amount of offered reserves and we investigate the suboptimality in comparison to an omniscient control system.Comment: 13 pages, 12 figures, 1 table, submitted to IEEE Transactions on Control Systems Technolog

Generation of four iPSC lines from four patients with Leigh syndrome carrying homoplasmic mutations m.8993T > G or m.8993T > C in the mitochondrial gene MT-ATP6.

We report the generation of four human iPSC lines (8993-A12, 8993-B12, 8993-C11, and 8993-D7) from fibroblasts of four patients affected by maternally inherited Leigh syndrome (MILS) carrying homoplasmic mutations m.8993T > G or m.8993T > C in the mitochondrial gene MT-ATP6. We used Sendai viruses to deliver reprogramming factors OCT4, SOX2, KLF4, and c-MYC. The established iPSC lines expressed pluripotency markers, exhibited a normal karyotype, were capable to form cells of the three germ layers in vitro, and retained the MT-ATP6 mutations at the same homoplasmic level of the parental fibroblasts

North Sea Wrecks - An interdisciplinary approach towards understanding the risks posed by wrecks containing munitions in the North Sea

Shipwrecks and dumped munitions continue to be a major hazard in the North Sea. Research within the EU Interreg project North Sea Wrecks (NSW), in cooperation with DLR, is generating new insights into the status of wrecks, the potential leakage of pollutants from munitions loads and the effects of contamination on exposed marine organisms in the North Sea environment. Further, historical documents are compared to models and visual inspections of the wreck. Samples of water, sediment and organisms are being analysed. Combining the results of these different fields of research allows for a better understanding of the environmental risks deriving from these wrecks. The extended article will detail the wreck of the SMS Mainz as a case study

Linking formal child care characteristics to children's socioemotional well-being: A comparative perspective

Most research on formal child care and children’s outcomes has focused on single countries. We, however, contend that policy context may moderate the association between formal child care characteristics and children’s socioemotional well-being. We examined this by comparing the Netherlands, Finland and the UK; three countries that differ regarding family policies. Of these three countries, Finland was recently ranked highest (ranked 1st) with regards to quality of child care in a recent analysis by the Economist ,followed by the UK (ranked 3rd) and then the Netherlands (ranked 7th) .We hypothesized that children who attend child - care settings in countries with higher- uality formal child- are provision would generally show better socioemotional outcomes. Data from the comparative ‘F amilies 24/7’ survey were used, including 990 parents with children aged 0–12. We distinguished between two age groups in our analysis. Results indicated that, compared to the UK, longer hours in formal care were less beneficial in the Netherlands. Furthermore, spen ding time in formal care during nonstandard hours was more harmful for children in Finland compared to the UK. Lastly, receiving care from multiple caregivers was more disruptive for British children than for Dutch children. No differences were found between Finland and the Netherlands

Social and health epidemiology of immigrants in Germany: past, present and future

Razum O, Wenner J. Social and health epidemiology of immigrants in Germany: past, present and future. Public Health Reviews. 2016;37(1): 4.Germany has experienced different forms of immigration for many decades. At the end of and after the Second World War, refugees, displaced persons and German resettlers constituted the largest immigrant group. In the 1950s, labor migration started, followed by family reunification. There has been a constant migration of refugees and asylum seekers reaching peaks in the early 1990s as well as today. Epidemiological research has increasingly considered the health, and the access to health care, of immigrants and people with migration background. In this narrative review we discuss the current knowledge on health of immigrants in Germany. The paper is based on a selective literature research with a focus on studies using representative data from the health reporting system. Our review shows that immigrants in Germany do not suffer from different diseases than non-immigrants, but they differ in their risk for certain diseases, in the resources to cope with theses risk and regarding access to treatment. We also identified the need for differentiation within the immigrant population, considering among others social and legal status, country of origin and duration of stay. Though most of the studies acknowledge the need for differentiation, the lack of data currently rules out analyses accounting for the existing diversity and thus a full understanding of health inequalities related to migration to Germany

Circadian clock mechanism driving mammalian photoperiodism.

The annual photoperiod cycle provides the critical environmental cue synchronizing rhythms of life in seasonal habitats. In 1936, Bünning proposed a circadian-basis for photoperiodic synchronization. Here, light-dark cycles entrain a circadian rhythm of photosensitivity, and the expression of summer or winter biology depends on whether light coincides with the phase of high photosensitivity. Formal studies support the universality of this so-called coincidence timer, but we lack understanding of the mechanisms involved. Here we show in mammals that coincidence timing takes place in the pars tuberalis of the pituitary, through a melatonin-dependent flip-flop switch between circadian transcriptional activation and repression. Long photoperiods produce short night-time melatonin signals, leading to induction of the circadian transcription factor BMAL2, in turn triggering summer biology through the eyes absent / thyrotrophin (EYA3 / TSH) pathway. Conversely, short photoperiods produce long melatonin signals, inducing circadian repressors including DEC1, in turn suppressing BMAL2 and the EYA3/TSH pathway, triggering winter biology. These actions are associated with progressive genome-wide changes in chromatin state, elaborating the effect of the circadian coincidence timer. Hence, circadian clock interactions with pituitary epigenetic pathways form the basis of the mammalian coincidence timer mechanism. Our results constitute a blueprint for circadian-based seasonal timekeeping in vertebrates

Die Vereinbarkeitsfrage für Männer: Welche Auswirkungen haben Elternzeiten und Teilzeitarbeit auf die Stundenlöhne von Vätern?

Studien zeigen, dass sich viele Väter in Deutschland wünschen, mehr Zeit mit ihren Kindern zu verbringen, dies aufgrund von langen Arbeitszeiten jedoch oft nicht umsetzen können. Elternzeit und Teilzeitarbeit könnten Optionen sein, die Vätern eine bessere Vereinbarkeit von Familie und Beruf ermöglichen. Arbeitsmarkttheorien legen jedoch nahe, dass die Inanspruchnahme solcher Maßnahmen mit Lohneinbußen verbunden ist. Dementsprechend entscheiden sich derzeit viele Väter gegen diese Möglichkeiten zur Vereinbarkeit von Familie und Beruf, da sie finanzielle Einbußen und Karrierenachteile befürchten. Um zu überprüfen, inwieweit diese Erwartungen empirisch fundiert sind, untersucht diese Arbeit daher den Einfluss von Elternzeit und Teilzeitarbeit auf die Stundenlöhne von Vätern. Fixed Effects-Analysen auf Basis des Sozio-oekonomischen Panels (SOEP) 1991-2013 und Familien in Deutschland (FiD) 2010-2013 zeigen, dass Teilzeitarbeit mit Lohneinbußen verbunden ist. Eine Elternzeit wirkt sich hingegen nicht auf die Löhne von Vätern aus - unabhängig davon, ob Väter nur die beiden für sie reservierten Partnermonate oder eine längere Elternzeit in Anspruch nehmen. Die Ergebnisse deuten somit darauf hin, dass die gesetzliche Elternzeit Vätern einen Rahmen bietet, in dem sie sich stärker in ihren Familien engagieren können, ohne berufliche Nachteile zu erfahren.As previous research shows, many German fathers would like to spend more time with their children, but long working hours often restrict their opportunities to do so. Parental leave and part-time work could help fathers to reconcile work and family. Yet, labor market theories predict that using such family-friendly policies may lead to wage penalties. Hence, many fathers decide against using such policies because they fear that parental leave or part-time work will lead to financial penalties and career disadvantages. This article evaluates this concern by empirically examining the effect of parental leave and part-time work on fathers’ hourly wages. Using data from the German Socio-Economic Panel (SOEP) 1991-2013 and Families in Germany (FiD) 2010-2013, results from fixed-effects regression analyses show that part-time work is associated with wage penalties, but parental leave is not - irrespective of whether fathers only took the two months fathers’ quota or longer parental leaves. The results hence indicate that the German parental leave legislation enables fathers to spend more time with their children while protecting them from wage penalties at work

Aldehydes phase shift the Gonyaulax clock

Aliphatic aldehydes ranging in chain length from one to four carbon atoms have a significant phase shifting effect upon the circadian rhythm of bioluminescence (glow) in the dinoflagellate ( Gonyaulax polyedra . Cells exposed for two hours to 18 mM acetaldehyde starting at about circadian time 12 experience a permanent phase delay of up to about 12 h. The phase response curve relationship with acetaldehyde is presented, as well as the relationship between concentration and phase delay for the four aldehydes studied. Reactions of aldehydes which may be implicated are discussed. The possibility that sulfhydryl reagents generally may perturb circadian systems is suggested.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47121/1/360_2004_Article_BF00689855.pd