Hyper-K\"ahler Fourfolds Fibered by Elliptic Products

Every fibration of a projective hyper-K\"ahler fourfold has fibers which are Abelian surfaces. In case the Abelian surface is a Jacobian of a genus two curve, these have been classified by Markushevich. We study those cases where the Abelian surface is a product of two elliptic curves, under some mild genericity hypotheses.Comment: 8 pages, EPIGA published versio

The Foundation of Hallyu – K-Pop's Coming of Age

We are still, collectively struggling to come to terms with Hallyu, Korean Wave. This is seen in the multitude of contrasting perspective that have been applied by journalists and academics alike since the turn of the new millennium. This article explores the various different approaches, argues for new theoretical paradigms, and explores, as a case study, how foundations for K-Pop as Korean Wave were built in the years before the term itself, Hallyu, was created

Numerical solution of a three-dimensional cubic cavity flow by using the Boltzmann equation

A three-dimensional cubic cavity flow has been analyzed for diatomic gases by using the Boltzmann equation with the Bhatnagar-Gross-Krook (B-G-K) model. The method of discrete ordinate was applied, and the diffuse reflection boundary condition was assumed. The results, which show a consistent trend toward the Navier-Stokes solution as the Knudson number is reduced, give us confidence to apply the method to a three-dimensional geometry for practical predictions of rarefied-flow characteristics. The CPU time and the main memory required for a three-dimensional geometry using this method seem reasonable

Said and the Mythmaking of Auerbach\u27s Mimesis

In her article Said and the Mythmaking of Auerbach\u27s Mimesis Hyeryung Hwang revisits critical debates on Edward W. Said\u27s unwitting participation in the mythmaking of Erich Auerbach\u27s Mimesis and analyzes the degree to which critical discourse overlook what Said actually wanted to revive, namely the spirit of philological methodology. Hwang argues that before Said worked on Mimesis, the book already acquired a sort of myth. Hwang attempts to go beyond the commonly held understanding of philology and suggest it as a methodology for historical synthesis whose dialectical tension between texts and history amounts to the synthesis of fact and truth

Core crush criterion to determine the strength of sandwich composite structures subjected to compression after impact

In this study a core crush criterion is proposed to determine the residual strength of impacted sandwich structures. The core of the sandwich is made of a Nomex Honeycomb core and the faces are laminated and remain thin. The mechanism of failure of this kind of structure under post-impact compressive loading is due to interaction between three mechanical behaviors: geometrical nonlinearity due to the skin’s neutral line off-set in the dent area, nonlinear response of the core and damages to the skins. For the type of sandwich analysed in this study, initially the core crushes at the apex of the damage. Using a finite element discrete modelling of the core previously proposed by the authors, the load corresponding to the crushing of the first cell can be computed and it gives the value of the residual strength for our criterion. Some geometric and material hypotheses are assumed in the damaged area mainly based on nondestructive inspection (NDI). The criterion is then applied to tests modelled by Lacy and Hwang [Lacy TE, Hwang Y. Numerical modelling of impact-damaged sandwich composites subjected to compression after impact loading. Compos Struct 2003;61:115–128]. It is shown that the criterion allows a good prediction of the tests except in the case of very small dents. Several sensitivity studies on the assumptions were made and it is shown that using this approach, the criterion is robust

Group Testing with Pools of Fixed Size

In the classical combinatorial (adaptive) group testing problem, one is given two integers $d$ and $n$, where $0\le d\le n$, and a population of $n$ items, exactly $d$ of which are known to be defective. The question is to devise an optimal sequential algorithm that, at each step, tests a subset of the population and determines whether such subset is contaminated (i.e. contains defective items) or otherwise. The problem is solved only when the $d$ defective items are identified. The minimum number of steps that an optimal sequential algorithm takes in general (i.e. in the worst case) to solve the problem is denoted by $M(d, n)$. The computation of $M(d, n)$ appears to be very difficult and a general formula is known only for $d = 1$. We consider here a variant of the original problem, where the size of the subsets to be tested is restricted to be a fixed positive integer $k$. The corresponding minimum number of tests by a sequential optimal algorithm is denoted by $M^{\lbrack k\rbrack}(d, n)$. In this paper we start the investigation of the function $M^{\lbrack k\rbrack}(d, n)$