Evidence for a preformed Cooper pair model in the pseudogap spectra of a Ca10(Pt4As8)(Fe2As2)5 single crystal with a nodal superconducting gap

For high-Tc superconductors, clarifying the role and origin of the pseudogap is essential for understanding the pairing mechanism. Among the various models describing the pseudogap, the preformed Cooper pair model is a potential candidate. Therefore, we present experimental evidence for the preformed Cooper pair model by studying the pseudogap spectrum observed in the optical conductivity of a Ca10(Pt4As8)(Fe2As2)5 (Tc = 34.6 K) single crystal. We observed a clear pseudogap structure in the optical conductivity and observed its temperature dependence. In the superconducting (SC) state, one SC gap with a gap size of {\Delta} = 26 cm-1, a scattering rate of 1/{\tau} = 360 cm-1 and a low-frequency extra Drude component were observed. Spectral weight analysis revealed that the SC gap and pseudogap are formed from the same Drude band. This means that the pseudogap is a gap structure observed as a result of a continuous temperature evolution of the SC gap observed below Tc. This provides clear experimental evidence for the preformed Cooper pair model.Comment: 15 pages, 4 figure

Application of Recent Developments in Deep Learning to ANN-based Automatic Berthing Systems

Previous studies on Artificial Neural Network (ANN)-based automatic berthing showed considerable increases in performance by training ANNs with a set of berthing datasets. However, the berthing performance deteriorated when an extrapolated initial position was given. To overcome the extrapolation problem and improve the training performance, recent developments in Deep Learning (DL) are adopted in this paper. Recent activation functions, weight initialization methods, input data-scaling methods, a higher number of hidden layers, and Batch Normalization (BN) are considered, and their effectiveness has been analyzed based on loss functions, berthing performance histories, and berthing trajectories. Finally, it is shown that the use of recent activation and weight initialization method results in faster training convergence and a higher number of hidden layers. This leads to a better berthing performance over the training dataset. It is found that application of the BN can overcome the extrapolated initial position problem

Exploring Customers’ Preferences for Online Games

Online content providers who use the Internet to distribute content experience an extremely competitive business environment. To survive in this environment, they have started charging a fee for the content that they provide. However, there have been very few success stories in commercializing online content. Although one of few success stories is the online game, it still has customers’ psychological resistance against paying a high fee for playing games. To pay back their high R&D or development costs quickly, many online game producers have a tendency to assign high prices to their online games. Without examining customers’ perceived prices for online games, many online game producers have tended to decide prices from their perspectives. Although many online game-related research works have focused on psychological and technical aspects, very few works have examined online gamers’ preferences carefully. This study aims at exploring online gamers’ preference by measuring their WTP (Willingness To Pay) for online games

OASIS: Online Application for the Survival Analysis of Lifespan Assays Performed in Aging Research

Aging is a fundamental biological process. Characterization of genetic and environmental factors that influence lifespan is a crucial step toward understanding the mechanisms of aging at the organism level. To capture the different effects of genetic and environmental factors on lifespan, appropriate statistical analyses are needed.We developed an online application for survival analysis (OASIS) that helps conduct various novel statistical tasks involved in analyzing survival data in a user-friendly manner. OASIS provides standard survival analysis results including Kaplan-Meier estimates and mean/median survival time by taking censored survival data. OASIS also provides various statistical tests including comparison of mean survival time, overall survival curve, and survival rate at specific time point. To visualize survival data, OASIS generates survival and log cumulative hazard plots that enable researchers to easily interpret their experimental results. Furthermore, we provide statistical methods that can analyze variances among survival datasets. In addition, users can analyze proportional effects of risk factors on survival.OASIS provides a platform that is essential to facilitate efficient statistical analyses of survival data in the field of aging research. Web application and a detailed description of algorithms are accessible from http://sbi.postech.ac.kr/oasis

Clinical relevance of ground glass opacity in 105 patients with miliary tuberculosis

SummaryBackgroundAfter the application of chest computed tomography (CT), ground glass opacity (GGO) was introduced as one of major accompanying findings of miliary tuberculosis (MT) in addition to miliary nodules. However, little is known about whether GGO is associated with the clinical manifestations and outcomes of MT. Therefore, the present study examined the clinical relevance of GGO in patients with MT.MethodsChest radiographs and CT scans of MT patients were retrospectively reviewed. Clinical manifestations and outcomes were compared in terms of the extent of GGO revealed by chest CT.ResultsConfirmed 105 MT patients were included. GGO was observed in 70 (67%) patients. MT patients with an extent of GGO >50% (n = 21) had symptoms of shorter duration, more frequent dyspnea, and more pronounced changes in the levels of acute phase reactants. Miliary nodules were less discernible on CT in those with an extent of GGO >50%. MT patients with an extent of GGO >50% were significantly associated with a longer hospital stay (p = 0.02) and with acute respiratory failure (p < 0.001) than those with an extent of GGO ≤50%. However, mortality among MT patients was not associated with the extent of GGO.ConclusionMT patients with an extent of GGO >50% had more rapidly progressive manifestations and a greater potential for delayed diagnosis and poorer prognosis. Nevertheless, mortality was not higher in confirmed MT patients with an extent of GGO >50% than in those with an extent of GGO ≤50%

Effect of proton irradiation on the fluctuation-induced magnetoconductivity of FeSe1−xTex thin films

The influence of proton irradiation on the fluctuation-induced magnetoconductivity of high quality FeSe1−xTex (x=0.4, 0.55) (FST) thin films has been investigated. The measurements were performed with magnetic fields up to 13 T applied in the two main crystal directions. The results were interpreted in terms of the Ginzburg–Landau approach for three-dimensional materials under a total-energy cutoff. The analysis shows that properly-tuned proton irradiation does not appreciably affect fundamental superconducting parameters like the Tc value, the upper critical fields or the anisotropy. This has important consequences from the point of view of possible applications due to the enhancement of vortex pinning induced by irradiation.YSK was supported by the NRF grant funded by the Ministry of Science, ICT and Future Planning (No. NRF-2015M2B2A9028507 and NRF-2016R1A2B4012672). TP was supported by the NRF grant funded by the Ministry of Science, ICT and Future Planning of Korea (No. 2012R1A3A2048816). JM acknowledges support by project FIS2016-79109-P (AEI/FEDER, UE) and by the Xunta de Galicia (project AGRUP 2015/11). SL was supported by the Global Research Network program through the NRF funded by the Ministry of Science and ICT & Future Planning (NRF-2014S1A2A2028361)S

Universality Class Of A Spinor Bose–Einstein Condensate Far From Equilibrium

Scale Invariance And Self-Similarity In Physics Provide A Unified Framework For Classifying Phases Of Matter And Dynamical Properties Near Equilibrium In Both Classical And Quantum Systems. This Paradigm Has Been Further Extended To Isolated Many-Body Quantum Systems Driven Far From Equilibrium, For Which The Physical Observables Exhibit Dynamical Scaling With Universal Scaling Exponents. Universal Dynamics Appear In A Wide Range Of Scenarios, Including Cosmology, Quark–gluon Matter, Ultracold Atoms And Quantum Spin Magnets. However, How The Universal Dynamics Depend On The Symmetry Of The Underlying Hamiltonian In Non-Equilibrium Systems Remains An Outstanding Challenge. Here We Report On The Classification Of Universal Coarsening Dynamics In A Quenched Two-Dimensional Ferromagnetic Spinor Bose Gas. We Observe Spatio-Temporal Scaling Of Spin Correlation Functions With Distinguishable Scaling Exponents That Characterize Binary And Diffusive Fluids. The Universality Class Of The Coarsening Dynamics Is Determined By The Symmetry Of The Order Parameter And The Dynamics Of The Topological Defects, Such As Domain Walls And Vortices. Our Results Categorize The Universality Classes Of Far-From-Equilibrium Quantum Dynamics Based On The Symmetry Properties Of The System

Temperature dependence of the superconducting energy gaps in Ca9.35La0.65(Pt-3 As-8)(Fe2As2)(5) single crystal

We measured the optical reflectivity R(ω) for an underdoped (Ca0.935La0.065)10(Pt3As8)(Fe2As2)5 single crystal and obtained the optical conductivity σ1(ω) using the K-K transformation. The normal state σ1(ω) at 30 K is well fitted by a Drude-Lorentz model with two Drude components (ωp1 = 1446 cm-1 and ωp2 = 6322 cm-1) and seven Lorentz components. Relative reflectometry was used to accurately determine the temperature dependence of the superconducting gap at various temperatures below Tc. The results clearly show the opening of a superconducting gap with a weaker second gap structure; the magnitudes for the gaps are estimated from the generalized Mattis-Bardeen model to be Δ1 = 30 and Δ2 = 50 cm-1, respectively, at T = 8 K, which both decrease with increasing temperature. The temperature dependence of the gaps was not consistent with one-band BCS theory but was well described by a two-band (hence, two gap) BCS model with interband interactions. The temperature dependence of the superfluid density is flat at low temperatures, indicating an s-wave full-gap superconducting state. © The Author(s) 2018.1