The Right Mutation Strength for Multi-Valued Decision Variables

The most common representation in evolutionary computation are bit strings. This is ideal to model binary decision variables, but less useful for variables taking more values. With very little theoretical work existing on how to use evolutionary algorithms for such optimization problems, we study the run time of simple evolutionary algorithms on some OneMax-like functions defined over $\Omega = \{0, 1, \dots, r-1\}^n$. More precisely, we regard a variety of problem classes requesting the component-wise minimization of the distance to an unknown target vector $z \in \Omega$. For such problems we see a crucial difference in how we extend the standard-bit mutation operator to these multi-valued domains. While it is natural to select each position of the solution vector to be changed independently with probability $1/n$, there are various ways to then change such a position. If we change each selected position to a random value different from the original one, we obtain an expected run time of $\Theta(nr \log n)$. If we change each selected position by either $+1$ or $-1$ (random choice), the optimization time reduces to $\Theta(nr + n\log n)$. If we use a random mutation strength $i \in \{0,1,\ldots,r-1\}^n$ with probability inversely proportional to $i$ and change the selected position by either $+i$ or $-i$ (random choice), then the optimization time becomes $\Theta(n \log(r)(\log(n)+\log(r)))$, bringing down the dependence on $r$ from linear to polylogarithmic. One of our results depends on a new variant of the lower bounding multiplicative drift theorem.Comment: an extended abstract of this work is to appear at GECCO 201

Uniaxial pressure dependencies of the phase boundary of TlCuCl_3

We present a thermal expansion and magnetostriction study of TlCuCl_3, which shows a magnetic-field induced transition from a spin gap phase to a Neel ordered phase. Using Ehrenfest relations we derive huge and strongly anisotropic uniaxial pressure dependencies of the respective phase boundary, e.g. the transition field changes by about $\pm 185$ GPa depending on the direction of uniaxial pressure.Comment: 2 pages, e figures; presented at SCES200

Magnetoelastic Coupling in the Spin-Dimer System TlCuCl3_3

We present high-resolution measurements of the thermal expansion and the magnetostriction of TlCuCl$_{3}$ which shows field-induced antiferromagnetic order. We find pronounced anomalies in the field and temperature dependence of different directions of the lattice signaling a large magnetoelastic coupling. The phase boundary is extremely sensitive to pressure, e.g. the transition field would change by about +/- 185$%/GPa under uniaxial pressure applied along certain directions. This drastic effect can unambiguously be traced back to changes of the intradimer coupling under uniaxial pressure. The interdimer couplings remain essentially unchanged under pressure, but strongly change when Tl is replaced by K.Comment: 4 pages with 4 figures include

The effect of dietary supplementation on Salmonella typhimurium colonization in the turkey crop

The pre-harvest use of supplements to reduce the incidence of crop contamination in turkeys was investigated. As opposed to other studies that used a carbohydrate or lactic acid bacteria supplementation prior to slaughter in extended feed withdrawal times, this study challenged poults before their natural nocturnal fast to determine the effects of supplementation on Salmonella challenge during grow-out. Three-week-old turkey poults, on a 2.5% lactose and Lactobacillus acidophilus (1x10⁹ organisms/liter) drinking water supplement from day of hatch, were orally challenged with 1.7x10⁸ naldixic-acid resistant Salmonella enterica serovar Typhimurium strain 4232. Crop ingesta and tissue were collected at timepoints 0.5, 4, 8, and 24 hours post challenge. Crop ingesta and crop wall tissue were separately weighed and pulverized in a stomacher. Ten-fold serial dilutions were made in peptone water and plated on XLT 4 media. An immunohistochemical staining procedure was used to explore the effects of supplementation on invasion, clearance, and multiplication of Salmonella typhimurium in vivo. Results from this study indicate that lactose and L. acidophilus supplementation did not reduce S. typhimurium colonization after challenge

Optimal Tableaux Method for Constructive Satisfiability Testing and Model Synthesis in the Alternating-time Temporal Logic ATL+

We develop a sound, complete and practically implementable tableaux-based decision method for constructive satisfiability testing and model synthesis in the fragment ATL+ of the full Alternating time temporal logic ATL*. The method extends in an essential way a previously developed tableaux-based decision method for ATL and works in 2EXPTIME, which is the optimal worst case complexity of the satisfiability problem for ATL+ . We also discuss how suitable parametrizations and syntactic restrictions on the class of input ATL+ formulae can reduce the complexity of the satisfiability problem.Comment: 45 page

Single-Element Beamforming using Multi-Mode Antenna Patterns

Recently, multi-mode antennas have been studied for communication as well as localization purposes. In this work, the capabilities provided by a single planar multi-mode radiator as a steerable multi-port antenna are explored. As an original contribution, the radiation characteristics of individual groups of modes of the single radiator are combined to optimize beamforming performance. Three possible codebook realizations are studied and compared. A new optimization criterion, gain by element factor, is introduced

In-situ probes for antenna array calibration

A novel calibration network for patch antennas is proposed. We introduce magnetically coupled in-situ probes, which excite the fundamental patch mode. In that way, finite array effects and mutual coupling can be detected, providing the opportunity for online calibration. The specific advantages of the approach are demonstrated for linearly polarized patch antennas. Measurement results of a single patch with the integrated probes agree with simulation. A two by two antenna array with in-situ probes is simulated to demonstrate the calibration accuracy in theory

Testing black hole no-hair theorem with OJ287

We examine the ability to test the black hole no-hair theorem at the 10% level in this decade using the binary black hole in OJ287. In the test we constrain the value of the dimensionless parameter q that relates the scaled quadrupole moment and spin of the primary black hole: q2 = -q 2 . At the present we can say that q = 1 \pm 0.3 (one), in agreement with General Relativity and the no-hair theorems. We demonstrate that this result can be improved if more observational data is found in historical plate archives for the 1959 and 1971 outbursts. We also show that the predicted 2015 and 2019 outbursts will be crucial in improving the accuracy of the test. Space-based photometry is required in 2019 July due the proximity of OJ287 to the Sun at the time of the outburst. The best situation would be to carry out the photometry far from the Earth, from quite a different vantage point, in order to avoid the influence of the nearby Sun. We have considered in particular the STEREO space mission which would be ideal if it has a continuation in 2019 or LORRI on board the New Horizons mission to Pluto.Comment: 14 pages, 14 figure