TY  - JOUR
A1  - Neumann, I.
A1  - Stoffel, Dominik
A1  - Hartje, Hendrik
A1  - Kunz, Wolfgang
T1  - Cell replication and redundancy elimination during placement for cycle time optimization
Y1  - 1999
ER  - 
TY  - JOUR
A1  - Kuznetsov, Sergey P.
A1  - Neumann, Eireen
A1  - Pikovskij, Arkadij
A1  - Sataev, I. G.
T1  - Critical point of tori collision in quasiperiodically forced systems
N2  - We report on a type of scaling behavior in quasiperiodically forced systems. On the parameter plane the critical point appears as a terminal point of the tori-collision bifurcation curve; its location is found numerically with high precision for two basic models, the forced supercritical circle map and the forced quadratic map. The hypothesis of universality, based on renormalization group arguments, is advanced to explain the observed scaling properties for the critical attractor and for the parameter plane arrangement in the neighborhood of the criticality.
Y1  - 2000
ER  - 
TY  - JOUR
A1  - Frübing, Peter
A1  - Kremmer, Alexander
A1  - Neumann, Werner
A1  - Gerhard, Reimund
A1  - Guy, I. L.
T1  - Dielectric relaxation in piezo-, pyro- and ferroelectric polyamide 11
N2  - Ferroelectric polyamide 11 films were prepared by melt-quenching, cold-drawing and electrical poling. Their ferroelectricity was studied by means of dielectric-hysteresis measurements. A remnant polarisation of up to 35 mC/m(2) and a coercive field of 75 MV/m were obtained. The piezoelectric d(33) coefficient and the pyroelectric coefficient of the films are reduced by annealing just below the melting region, but remain at about 3 pC/N and 8 muC/(m(2)K), respectively, during further heat treatment. Differential scanning calorimetry (DSC), dielectric relaxation spectroscopy (DRS) and thermally stimulated depolarisation (TSD) were applied for investigating the conformational changes induced by melt-quenching, cold-drawing and annealing. The results indicate that the cold-drawn film mainly consists of a rigid amorphous phase which exhibits considerably lower conductivity, no glass transition and consequently no dielectric a relaxation. Instead, an a, relaxation is found, which is related to chain motions in regions of the rigid amorphous phase where the amide-group dipoles are not perfectly ordered. Annealing removes imperfectly ordered structures, but does not affect the ferroelectric polarisation. Therefore, it may be concluded that essentially the a, relaxation causes the thermally non-stable part of the piezo- and pyroelectricity in polyamide 11
Y1  - 2004
ER  - 
TY  - GEN
A1  - Frieler, Katja
A1  - Levermann, Anders
A1  - Elliott, J.
A1  - Heinke, J.
A1  - Arneth, A.
A1  - Bierkens, M. F. P.
A1  - Ciais, Philippe
A1  - Clark, D. B.
A1  - Deryng, D.
A1  - Doell, P.
A1  - Falloon, P.
A1  - Fekete, B.
A1  - Folberth, Christian
A1  - Friend, A. D.
A1  - Gellhorn, C.
A1  - Gosling, S. N.
A1  - Haddeland, I.
A1  - Khabarov, N.
A1  - Lomas, M.
A1  - Masaki, Y.
A1  - Nishina, K.
A1  - Neumann, K.
A1  - Oki, T.
A1  - Pavlick, R.
A1  - Ruane, A. C.
A1  - Schmid, E.
A1  - Schmitz, C.
A1  - Stacke, T.
A1  - Stehfest, E.
A1  - Tang, Q.
A1  - Wisser, D.
A1  - Huber, V.
A1  - Piontek, Franziska
A1  - Warszawski, L.
A1  - Schewe, Jacob
A1  - Lotze-Campen, Hermann
A1  - Schellnhuber, Hans Joachim
T1  - A framework for the cross-sectoral integration of multi-model impact projections
BT  - land use decisions under climate impacts uncertainties
T2  - Earth system dynamics
N2  - Climate change and its impacts already pose considerable challenges for societies that will further increase with global warming (IPCC, 2014a, b). Uncertainties of the climatic response to greenhouse gas emissions include the potential passing of large-scale tipping points (e.g. Lenton et al., 2008; Levermann et al., 2012; Schellnhuber, 2010) and changes in extreme meteorological events (Field et al., 2012) with complex impacts on societies (Hallegatte et al., 2013). Thus climate change mitigation is considered a necessary societal response for avoiding uncontrollable impacts (Conference of the Parties, 2010). On the other hand, large-scale climate change mitigation itself implies fundamental changes in, for example, the global energy system. The associated challenges come on top of others that derive from equally important ethical imperatives like the fulfilment of increasing food demand that may draw on the same resources. For example, ensuring food security for a growing population may require an expansion of cropland, thereby reducing natural carbon sinks or the area available for bio-energy production. So far, available studies addressing this problem have relied on individual impact models, ignoring uncertainty in crop model and biome model projections. Here, we propose a probabilistic decision framework that allows for an evaluation of agricultural management and mitigation options in a multi-impact-model setting. Based on simulations generated within the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), we outline how cross-sectorally consistent multi-model impact simulations could be used to generate the information required for robust decision making.

Using an illustrative future land use pattern, we discuss the trade-off between potential gains in crop production and associated losses in natural carbon sinks in the new multiple crop-and biome-model setting. In addition, crop and water model simulations are combined to explore irrigation increases as one possible measure of agricultural intensification that could limit the expansion of cropland required in response to climate change and growing food demand. This example shows that current impact model uncertainties pose an important challenge to long-term mitigation planning and must not be ignored in long-term strategic decision making.
T3  - Zweitveröffentlichungen der Universität Potsdam : Mathematisch-Naturwissenschaftliche Reihe - 457 
KW  - global food demand
KW  - water availability
KW  - elevated CO2
KW  - future
KW  - carbon
KW  - system
KW  - productivity
KW  - agriculture
KW  - emissions
KW  - scarcity
Y1  - 2018
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:517-opus4-407968
ER  - 
TY  - JOUR
A1  - Frieler, Katja
A1  - Levermann, Anders
A1  - Elliott, J.
A1  - Heinke, Jens
A1  - Arneth, A.
A1  - Bierkens, M. F. P.
A1  - Ciais, Philippe
A1  - Clark, D. B.
A1  - Deryng, D.
A1  - Doell, P.
A1  - Falloon, P.
A1  - Fekete, B.
A1  - Folberth, Christian
A1  - Friend, A. D.
A1  - Gellhorn, C.
A1  - Gosling, S. N.
A1  - Haddeland, I.
A1  - Khabarov, N.
A1  - Lomas, M.
A1  - Masaki, Y.
A1  - Nishina, K.
A1  - Neumann, K.
A1  - Oki, T.
A1  - Pavlick, R.
A1  - Ruane, A. C.
A1  - Schmid, E.
A1  - Schmitz, C.
A1  - Stacke, T.
A1  - Stehfest, E.
A1  - Tang, Q.
A1  - Wisser, D.
A1  - Huber, Veronika
A1  - Piontek, Franziska
A1  - Warszawski, Lila
A1  - Schewe, Jacob
A1  - Lotze-Campen, Hermann
A1  - Schellnhuber, Hans Joachim
T1  - A framework for the cross-sectoral integration of multi-model impact projections
BT  - land use decisions under climate impacts uncertainties
JF  - Earth system dynamics
N2  - Climate change and its impacts already pose considerable challenges for societies that will further increase with global warming (IPCC, 2014a, b). Uncertainties of the climatic response to greenhouse gas emissions include the potential passing of large-scale tipping points (e.g. Lenton et al., 2008; Levermann et al., 2012; Schellnhuber, 2010) and changes in extreme meteorological events (Field et al., 2012) with complex impacts on societies (Hallegatte et al., 2013). Thus climate change mitigation is considered a necessary societal response for avoiding uncontrollable impacts (Conference of the Parties, 2010). On the other hand, large-scale climate change mitigation itself implies fundamental changes in, for example, the global energy system. The associated challenges come on top of others that derive from equally important ethical imperatives like the fulfilment of increasing food demand that may draw on the same resources. For example, ensuring food security for a growing population may require an expansion of cropland, thereby reducing natural carbon sinks or the area available for bio-energy production. So far, available studies addressing this problem have relied on individual impact models, ignoring uncertainty in crop model and biome model projections. Here, we propose a probabilistic decision framework that allows for an evaluation of agricultural management and mitigation options in a multi-impact-model setting. Based on simulations generated within the Inter-Sectoral Impact Model Intercomparison Project (ISI-MIP), we outline how cross-sectorally consistent multi-model impact simulations could be used to generate the information required for robust decision making.
 Using an illustrative future land use pattern, we discuss the trade-off between potential gains in crop production and associated losses in natural carbon sinks in the new multiple crop-and biome-model setting. In addition, crop and water model simulations are combined to explore irrigation increases as one possible measure of agricultural intensification that could limit the expansion of cropland required in response to climate change and growing food demand. This example shows that current impact model uncertainties pose an important challenge to long-term mitigation planning and must not be ignored in long-term strategic decision making.
Y1  - 2015
U6  - https://doi.org/10.5194/esd-6-447-2015
SN  - 2190-4979
SN  - 2190-4987
VL  - 6
IS  - 2
SP  - 447
EP  - 460
PB  - Copernicus
CY  - Göttingen
ER  -