The Influence of the Microwave Power on Josephson Microwave Absorption in High- Temperature Superconductors

The influence of the microwave power on the internal Josephson Junction System (JJS) in granular high T$\text{}_{c}$, superconductors was investigated using EPR methodology. Josephson Microwave Absorption signal was used to monitor local temperature of the Josephson Junction System while the bulk sample temperature was measured by a thermocouple. The effect of the JJS overheating is discussed as the consequence of an interaction between JJS, microwave field and the bulk sample

High-Pressure Microwave Study of YBa2\text{}_{2}Cu3\text{}_{3}O7−δ\text{}_{7-δ}-Pb(Sc0.5\text{}_{0.5}Ta0.5\text{}_{0.5})O3\text{}_{3} Composite

The ferroelectric relaxor Pb(Sc$\text{}_{0.5}$Ta$\text{}_{0.5}$)O$\text{}_{3}$-superconductor YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-δ}$ 50% in weight composite exhibits the onset critical temperature T$\text{}_{c}$=95 K. High pressure studies yield the factor dT$\text{}_{c}$/dp of 1.0 K/GPa, close to the value observed for a pure YBa$\text{}_{2}$Cu$\text{}_{3}$O$\text{}_{7-δ}$ compound. The microwave absorption studies show the significant role of the intergrain weak links

Hybrid Metaheuristics for Multi-objective combinatorial optimization

Many real-world optimization problems can be modelled as combinatorial optimization problems. Often, these problems are characterized by their large size and the presence of multiple, conflicting objectives. Despite progress in solving multi-objective combinatorial optimization problems exactly, the large size often means that heuristics are required for their solution in acceptable time. Since the middle of the nineties the trend is towards heuristics that “pick and choose” elements from several of the established metaheuristic schemes. Such hybrid approximation techniques may even combine exact and heuristic approaches. In this chapter we give an overview over approximation methods in multi-objective combinatorial optimization. We briefly summarize “classical” metaheuristics and focus on recent approaches, where metaheuristics are hybridized and/or combined with exact methods