380,881 research outputs found
Ergodicity and entropy in sequence spaces
The infinite permutations of possible moves in a game, or positions on a game
board, form a one-sided sequence space. We are working with a probability
measure on the space of measurable subsets of the sequence space. We are
studying a shift transformation on this space, which is measure preserving.
We explore conditions under which the shift transformation is ergodic and
calculate the entropy of the shift that is associated with the steady state of the
game where applicable. These concepts are exemplified by the games Rock,
Paper, Scissors and Monopoly. We then create new games and study how the
properties of ergodicity and entropy change with respect to different aspects of
the games
Critical behavior and magnetocaloric effect in Tsai-type 2/1 and 1/1 quasicrystal approximants
Stable Tsai-type quinary 1/1 and 2/1 approximant crystals (ACs) with chemical
compositions Au56.25Al10Cu7In13Tb13.75 and Au55.5Al10Cu7In13Tb14.5,
respectively, exhibiting ferromagnetic (FM) long-range orders were successfully
synthesized and studied for their magnetic properties and magnetocaloric
effect. The 1/1 and 2/1 ACs primarily differ in their long-range atomic
arrangement and rare earth (RE) distribution, with the latter approaching
quasiperiodic order while still preserving periodicity. Analyses based on the
scaling principle and Kouvel-Fisher (KF) relations suggested mean-field-like
behavior near Curie temperatures in both compounds. From magnetization
measurements and the Maxwell equation, a magnetic entropy change of -4.3 and
-4.1 J/K mol Tb were derived under a magnetic field change of 7 T for the 1/1
and 2/1 ACs, respectively. The results indicated a prominent role of
intra-cluster magnetic interactions on critical behavior and magnetic entropy
of the Tsai-type compounds
Runtime Verification of Self-Adaptive Systems with Changing Requirements
To accurately make adaptation decisions, a self-adaptive system needs precise
means to analyze itself at runtime. To this end, runtime verification can be
used in the feedback loop to check that the managed system satisfies its
requirements formalized as temporal-logic properties. These requirements,
however, may change due to system evolution or uncertainty in the environment,
managed system, and requirements themselves. Thus, the properties under
investigation by the runtime verification have to be dynamically adapted to
represent the changing requirements while preserving the knowledge about
requirements satisfaction gathered thus far, all with minimal latency. To
address this need, we present a runtime verification approach for self-adaptive
systems with changing requirements. Our approach uses property specification
patterns to automatically obtain automata with precise semantics that are the
basis for runtime verification. The automata can be safely adapted during
runtime verification while preserving intermediate verification results to
seamlessly reflect requirement changes and enable continuous verification. We
evaluate our approach on an Arduino prototype of the Body Sensor Network and
the Timescales benchmark. Results show that our approach is over five times
faster than the typical approach of redeploying and restarting runtime monitors
to reflect requirements changes, while improving the system's trustworthiness
by avoiding interruptions of verification.Comment: 18th Symposium on Software Engineering for Adaptive and Self-Managing
Systems (SEAMS 2023
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