Optimization of double drive pulse pumping in Ne-like Ge x-ray lasers

Pumping of the Ne-like Ge x-ray laser with two 100 ps duration pulses (a prepulse and main pulse) is investigated using a fluid and atomic physics code coupled to a 3D ray tracing postprocessor code. The modeling predicts the optimum ratio of the irradiance of the two pulses for the maximum x-ray laser output resulting from the balance between the relative lower electron density gradients and wider gain region which is produced with a larger prepulse and the higher peak gain coefficients produced with a small prepulse. With a longer pulse interval between prepulse and main pulse, a relatively lower optimum pulse ratio is found. The threshold irradiance of the main driving pulse with a prepulse required to make an order of magnitude enhancement of laser output compared to irradiation without a prepulse is also found at 3-4x10(13) W/cm(2) for Ne-like Ge. (C) 1998 American Institute of Physics

The Effects of UV Exposure on the Antioxidant Enzyme Systems of Anemones

Superoxide dismutase (SOD), catalase (CAT) and glutathione peroxidase (GSH-Px) which are housekeeping enzymes protect cells from harmful side effects of reactive oxygen species (ROS). Anemonia sulcata var. smaragdina andAnemonia rustica are widely distributed along the Turkish coastlines of Aegean Sea. Recent studies showed that the environmental stresses such as elevated temperature, ultraviolet light, pathogen infection and decreased salinity might cause well known bleaching effects in Anemonia species. The effect of UV-light on antioxidant enzyme activities such as SOD, CAT, GSH-Px, protein levels and secondary pigments were determined in A. sulcata var. smaragdina and A. rustica. SOD, CAT, GSH-Px activities, protein levels and secondary pigments of these morphotypes were observed in both tentacles and columns separately. According to studies on bleaching, the elevated UV radiation may cause this bleaching event as a stress factor. However, in the present study no bleaching event was observed in anemone samples even they are exposed to 5 hours UV-exposure. Moreover, UV exposure did not change antioxidant systems remarkably. However, many investigations are still needed for obtaining the complete picture of the effects of UV-light on cellular pathways of cnidarian–algal symbiosis

Estimating the chance of success in IVF treatment using a ranking algorithm

In medicine, estimating the chance of success for treatment is important in deciding whether to begin the treatment or not. This paper focuses on the domain of in vitro fertilization (IVF), where estimating the outcome of a treatment is very crucial in the decision to proceed with treatment for both the clinicians and the infertile couples. IVF treatment is a stressful and costly process. It is very stressful for couples who want to have a baby. If an initial evaluation indicates a low pregnancy rate, decision of the couple may change not to start the IVF treatment. The aim of this study is twofold, firstly, to develop a technique that can be used to estimate the chance of success for a couple who wants to have a baby and secondly, to determine the attributes and their particular values affecting the outcome in IVF treatment. We propose a new technique, called success estimation using a ranking algorithm (SERA), for estimating the success of a treatment using a ranking-based algorithm. The particular ranking algorithm used here is RIMARC. The performance of the new algorithm is compared with two well-known algorithms that assign class probabilities to query instances. The algorithms used in the comparison are Naïve Bayes Classifier and Random Forest. The comparison is done in terms of area under the ROC curve, accuracy and execution time, using tenfold stratified cross-validation. The results indicate that the proposed SERA algorithm has a potential to be used successfully to estimate the probability of success in medical treatment. © 2015, The Author(s)

Large-area semi-transparent light-sensitive nanocrystal skins

Cataloged from PDF version of article.We report a large-area, semi-transparent, light-sensitive nanocrystal skin (LS-NS) platform consisting of single monolayer colloidal nanocrystals. LS-NS devices, which were fabricated over areas up to 48 cm(2) using spray-coating and several cm-squares using dip-coating, are operated on the principle of photogenerated potential buildup, unlike the conventional charge collection. Implementing proof-of-concept devices using CdTe nanocrystals with ligand removal, we observed a substantial sensitivity enhancement factor of similar to 73%, accompanied with a 3-fold faster response time (<100 ms). With fully sealed nanocrystal monolayers, LS-NS is found to be highly stable under ambient conditions, promising for low-cost large-area UV/visible sensing in windows and facades of smart buildings. (C) 2012 Optical Society of Americ

Information-Theoretic Active Learning for Content-Based Image Retrieval

We propose Information-Theoretic Active Learning (ITAL), a novel batch-mode active learning method for binary classification, and apply it for acquiring meaningful user feedback in the context of content-based image retrieval. Instead of combining different heuristics such as uncertainty, diversity, or density, our method is based on maximizing the mutual information between the predicted relevance of the images and the expected user feedback regarding the selected batch. We propose suitable approximations to this computationally demanding problem and also integrate an explicit model of user behavior that accounts for possible incorrect labels and unnameable instances. Furthermore, our approach does not only take the structure of the data but also the expected model output change caused by the user feedback into account. In contrast to other methods, ITAL turns out to be highly flexible and provides state-of-the-art performance across various datasets, such as MIRFLICKR and ImageNet.Comment: GCPR 2018 paper (14 pages text + 2 pages references + 6 pages appendix

Optoelectronic switches based on diffusive conduction

Cataloged from PDF version of article.We study the process of diffusive conduction that we use in our optoelectronic switches to achieve rapid optical switching (on a picosecond time scale). We present the characteristic Green's function of the diffusive conduction derived for arbitrary initial conditions. We also report the series solutions of the diffusive conduction obtained for different boundary conditions (V=0 and del V=0 along the device contact lines) in different device geometries (rectangular and circular mesas). Using these analytical results, we investigate the effect of boundary conditions on the switching operation and the steady state behavior in optical links. We demonstrate the feasibility of using such diffusive conductive optoelectronic switches to establish optical links in return-to-zero and non-return-to-zero coding schemes. For multichannel optical switching, we discuss possible use of a single optoelectronic switch to accommodate multiple channels at once, with > 100 optical channels (with a 2000 mm(-2) channel density and 50 GHz, leading to a 5 Tb/s aggregate transmission in principle. This approach of using multiple parallel channels on a single switch is completely opposite to the traditional idea of arraying many switches. This proposed scheme eliminates the need for on-chip switch integration and the need for the alignment of the optical channels to the integrated individual switches. (c) 2006 American Institute of Physics

Probing scalar-pseudoscalar mixing in the CP violating MSSM at high-energy e+e−e^+e^- colliders

We study the production processes $e^+e^-\to H^0_iZ$, $H^0_iH^0_j$ and $H^0_i\nu_e\overline \nu_e$ in the context of the CP violating MSSM. In a given channel we show that the cross-section for all i (=1,2,3) can be above 0.1 fb provided M_{H_{2,3}}\la 300 GeV. This should be detectable at a Next Linear Collider and would provide evidence for scalar-pseudoscalar mixing.Comment: 17 pages, RevTex, 4 ps figures, figure 4 changed, minor modifications to text, version to appear in PR