Analysis of accidental iceberg impacts with large passenger vessels

The number of collisions between ships and ice are increasing with the increase of ships sailing in Arctic areas. It is necessary to research on large passenger ships subjected to iceberg impact, since it may cause huge human life loss. The method to design ice going ship nowadays is presented. The conventional design of ship structures is carried out in the ULS format. But the design of ship-iceberg impact scenario should fall into ALS design, due to its rare and large load property. ULS design for ship-iceberg collision will yield over-designed structures. The method to get the design ice load according to IACS Polar Class rules is introduced. The design method is based on simplified method and it doesn t take the ship-iceberg collision into consideration. For engineering calculations it is common to decouple the collision event into external and internal mechanics. The basic ideas about splitting the impact process into these two parts is introduced. Some numerical simulation cases in Liu s paper are also presented to give a more clear introduction. The internal mechanics depends on the relative strength of the ship structures and Iceberg, so it is necessary to establish an accurate ice material model. The most important mechanical and physical properties of ice are described. The material model for iceberg developed by Liu is also presented. The numerical simulation using this ice material is also presented to show that this ice material model is validated. The major work in this master thesis is to establish an FE model for both ship structures and ice floe, and then run impact simulations in Ls-Dyna. The establishment of FE model of ship structures and Ice floe is introduced in detail. The impact analysis setup in Ls-Dyna prepost is also presented. Some key points about how to get appropriate numerical simulation results are presented for anyone who wants to do this kind of analysis again. The simulation results are presented in detail. Basically, the ship is designed with enough resistance against ice floe impact load. The ship can crush the ice completely without being significant damaged. One simulation was run using rigid material, and the ship shell was easily penetrated. The damage pattern of the ship structures is analyzed for this simulation. Some simulations were run with an error, which makes the ice uncrushable. In these cases, the ice floe will cause significant deformation on the ship shell but not penetrate it. The results are also presented to make a comparison with the crushed ice

Controlling contagion processes in activity driven networks

The vast majority of strategies aimed at controlling contagion processes on networks consider the connectivity pattern of the system either quenched or annealed. However, in the real world, many networks are highly dynamical and evolve, in time, concurrently with the contagion process. Here, we derive an analytical framework for the study of control strategies specifically devised for a class of time-varying networks, namely activity-driven networks. We develop a block variable mean-field approach that allows the derivation of the equations describing the coevolution of the contagion process and the network dynamic. We derive the critical immunization threshold and assess the effectiveness of three different control strategies. Finally, we validate the theoretical picture by simulating numerically the spreading process and control strategies in both synthetic networks and a large-scale, real-world, mobile telephone call data set

Cosmic variance of the local Hubble flow in large-scale cosmological simulations

The increasing precision in the determination of the Hubble parameter has reached a per cent level at which large-scale cosmic flows induced by inhomogeneities of the matter distribution become non-negligible. Here, we use large-scale cosmological N-body simulations to study statistical properties of the local Hubble parameter as measured by local observers. We show that the distribution of the local Hubble parameter depends not only on the scale of inhomogeneities, but also on how one defines the positions of observers in the cosmic web and what reference frame is used. Observers located in random dark matter haloes measure on average lower expansion rates than those at random positions in space or in the centres of cosmic voids, and this effect is stronger from the halo rest frames compared to the cosmic microwave background (CMB) rest frame. We compare the predictions for the local Hubble parameter with observational constraints based on Type Ia supernova (SNIa) and CMB observations. Due to cosmic variance, for observers located in random haloes we show that the Hubble constant determined from nearby SNIa may differ from that measured from the CMB by ±0.8 per cent at 1σ statistical significance. This scatter is too small to significantly alleviate a recently claimed discrepancy between current measurements assuming a flat Λ cold dark matter (ΛCDM) model. However, for observers located in the centres of the largest voids permitted by the standard ΛCDM model, we find that Hubble constant measurements from SNIa would be biased high by 5 per cent, rendering this tension non-existent in this extreme case

統合失調症患者死後脳におけるTP53に焦点をあてた発現変動遺伝子解析

Tohoku University修士（医科学）修士論文あるいは修士論文要旨 (Summary of Thesis(MR))thesi

Constraints on the shapes of galaxy dark matter haloes from weak gravitational lensing

We study the shapes of galaxy dark matter haloes by measuring the anisotropy of the weak gravitational lensing signal around galaxies in the second Red-sequence Cluster Survey (RCS2). We determine the average shear anisotropy within the virial radius for three lens samples: all galaxies with 19<m_r'<21.5, and the `red' and `blue' samples, whose lensing signals are dominated by massive low-redshift early-type and late-type galaxies, respectively. To study the environmental dependence of the lensing signal, we separate each lens sample into an isolated and clustered part and analyse them separately. We also measure the azimuthal dependence of the distribution of physically associated galaxies around the lens samples. We find that these satellites preferentially reside near the major axis of the lenses, and constrain the angle between the major axis of the lens and the average location of the satellites to =43.7 deg +/- 0.3 deg for the `all' lenses, =41.7 deg +/- 0.5 deg for the `red' lenses and =42.0 deg +/- 1.4 deg for the `blue' lenses. For the `all' sample, we find that the anisotropy of the galaxy-mass cross-correlation function =0.23 +/- 0.12, providing weak support for the view that the average galaxy is embedded in, and preferentially aligned with, a triaxial dark matter halo. Assuming an elliptical Navarro-Frenk-White (NFW) profile, we find that the ratio of the dark matter halo ellipticity and the galaxy ellipticity f_h=e_h/e_g=1.50+1.03-1.01, which for a mean lens ellipticity of 0.25 corresponds to a projected halo ellipticity of e_h=0.38+0.26-0.25 if the halo and the lens are perfectly aligned. For isolated galaxies of the `all' sample, the average shear anisotropy increases to =0.51+0.26-0.25 and f_h=4.73+2.17-2.05, whilst for clustered galaxies the signal is consistent with zero. (abridged)Comment: 28 pages, 23 figues, accepted for publication in A&

MUD: Towards a Large-Scale and Noise-Filtered UI Dataset for Modern Style UI Modeling

The importance of computational modeling of mobile user interfaces (UIs) is undeniable. However, these require a high-quality UI dataset. Existing datasets are often outdated, collected years ago, and are frequently noisy with mismatches in their visual representation. This presents challenges in modeling UI understanding in the wild. This paper introduces a novel approach to automatically mine UI data from Android apps, leveraging Large Language Models (LLMs) to mimic human-like exploration. To ensure dataset quality, we employ the best practices in UI noise filtering and incorporate human annotation as a final validation step. Our results demonstrate the effectiveness of LLMs-enhanced app exploration in mining more meaningful UIs, resulting in a large dataset MUD of 18k human-annotated UIs from 3.3k apps. We highlight the usefulness of MUD in two common UI modeling tasks: element detection and UI retrieval, showcasing its potential to establish a foundation for future research into high-quality, modern UIs

Cluster Lenses

Clusters of galaxies are the most recently assembled, massive, bound structures in the Universe. As predicted by General Relativity, given their masses, clusters strongly deform space-time in their vicinity. Clusters act as some of the most powerful gravitational lenses in the Universe. Light rays traversing through clusters from distant sources are hence deflected, and the resulting images of these distant objects therefore appear distorted and magnified. Lensing by clusters occurs in two regimes, each with unique observational signatures. The strong lensing regime is characterized by effects readily seen by eye, namely, the production of giant arcs, multiple-images, and arclets. The weak lensing regime is characterized by small deformations in the shapes of background galaxies only detectable statistically. Cluster lenses have been exploited successfully to address several important current questions in cosmology: (i) the study of the lens(es) - understanding cluster mass distributions and issues pertaining to cluster formation and evolution, as well as constraining the nature of dark matter; (ii) the study of the lensed objects - probing the properties of the background lensed galaxy population - which is statistically at higher redshifts and of lower intrinsic luminosity thus enabling the probing of galaxy formation at the earliest times right up to the Dark Ages; and (iii) the study of the geometry of the Universe - as the strength of lensing depends on the ratios of angular diameter distances between the lens, source and observer, lens deflections are sensitive to the value of cosmological parameters and offer a powerful geometric tool to probe Dark Energy. In this review, we present the basics of cluster lensing and provide a current status report of the field.Comment: About 120 pages - Published in Open Access at: http://www.springerlink.com/content/j183018170485723/ . arXiv admin note: text overlap with arXiv:astro-ph/0504478 and arXiv:1003.3674 by other author