Introduction to the GaLA Conf 2018 Special Issue

Introduction to the IJSG Special Issue dedicated to the best papers of Games and Learning Alliance Conference (GaLA Conf) 2017, Lisbo

Radiopurity of Micromegas readout planes

Micromesh Gas Amplification Structures (Micromegas) are being used in an increasing number of Particle Physics applications since their conception fourteen years ago. More recently, they are being used or considered as readout of Time Projection Chambers (TPCs) in the field of Rare Event searches (dealing with dark matter, axions or double beta decay). In these experiments, the radiopurity of the detector components and surrounding materials is measured and finely controlled in order to keep the experimental background as low as possible. In the present paper, the first measurement of the radiopurity of Micromegas planes obtained by high purity germanium spectrometry in the low background facilities of the Canfranc Underground Laboratory (LSC) is presented. The obtained results prove that Micromegas readouts of the microbulk type are currently manufactured with radiopurity levels below 30 microBq/cm2 for Th and U chains and ~60 microBq/cm2 for 40K, already comparable to the cleanest detector components of the most stringent low background experiments at present. Taking into account that the studied readouts were manufactured without any specific control of the radiopurity, it should be possible to improve these levels after dedicated development.Comment: 15 pages, 2 figure

Current-voltage characteristic and stability in resonant-tunneling n-doped semiconductor superlattices

We review the occurrence of electric-field domains in doped superlattices within a discrete drift model. A complete analysis of the construction and stability of stationary field profiles having two domains is carried out. As a consequence, we can provide a simple analytical estimation for the doping density above which stable stable domains occur. This bound may be useful for the design of superlattices exhibiting self-sustained current oscillations. Furthermore we explain why stable domains occur in superlattices in contrast to the usual Gunn diode.Comment: Tex file and 3 postscript figure

Shopping For Privacy: How Technology in Brick-and-Mortar Retail Stores Poses Privacy Risks for Shoppers

As technology continues to rapidly advance, the American legal system has failed to protect individual shoppers from the technology implemented into retail stores, which poses significant privacy risks but does not violate the law. In particular, I examine the technologies implemented into many brick-and-mortar stores today, many of which the average everyday shopper has no idea exists. This Article criticizes these technologies, suggesting that many, if not all of them, are questionable in their legality taking advantage of their status in a legal gray zone. Because the American judicial system cannot adequately protect the individual shopper from these questionable privacy practices, I call upon the Federal Trade Commission, the de facto privacy regulator in the United States, to increase its policing of physical retail stores to protect the shopper from any further harm

Editorial, Vol. 5, No. 3

IJSG September 2018 Editorial - Vol. 5, No.

Acceleration of Randomized Kaczmarz Method via the Johnson-Lindenstrauss Lemma

The Kaczmarz method is an algorithm for finding the solution to an overdetermined consistent system of linear equations Ax=b by iteratively projecting onto the solution spaces. The randomized version put forth by Strohmer and Vershynin yields provably exponential convergence in expectation, which for highly overdetermined systems even outperforms the conjugate gradient method. In this article we present a modified version of the randomized Kaczmarz method which at each iteration selects the optimal projection from a randomly chosen set, which in most cases significantly improves the convergence rate. We utilize a Johnson-Lindenstrauss dimension reduction technique to keep the runtime on the same order as the original randomized version, adding only extra preprocessing time. We present a series of empirical studies which demonstrate the remarkable acceleration in convergence to the solution using this modified approach

JOINT DEVELOPMENT OF HYDROCARBON RESOURCES IN THE SOUTH CHINA SEA. Towards Strengthening Regional Cooperation in the Spratly Islands.

The complexity of the South China Sea (SCS) disputes matched with the tremendous exploitation potential of hydrocarbon resources have stunted the development of economic activities in the Spratly Islands for many years. The challenge facing the international community in this regard borders on how to manage or resolve the disputes in such manner that economic growth is not impeded, and the marine environment is protected and preserved. This thesis therefore argues that Law of the Sea has set the framework for cooperation over hydrocarbon resources in the Spratly Islands. This thesis also argues that the provisions of Article 123 of UNCLOS read together with paragraph 3 of Articles 74 and 83 of UNCLOS require all coastal States to cooperate in implementing a joint development agreement when seeking to exploit in disputed maritime areas, and to refrain from unilateral actions that may jeopardize or hamper the interest of States at the final delimitation

Bibliografia prac astronoma i historyka nauk ścisłych Piotra Flina (1945–2018)

The bibliography presents the list of publications by Piotr Flin (1945–2018), an astronomer and exact sciences historian.Niniejsze opracowanie przedstawia spis dwustu pięćdziesięciu (w tym dwustu czterdziestu trzech odrębnych) publikacji śp. Piotra Flina i spis trzech prac doktorskich, których był promotorem. Przedstawiany spis publikacji nie rości sobie pretensji do bycia kompletną bibliografią prac tego Autora. Z uwagi na specyfikę opracowania, publikacje współautorskie wymienione są w porządku czasowym, a nie alfabetycznym współautorów. Dodatkowo, w porównaniu ze standardowym stylem zapisu bibliografii przyjętym w czasopiśmie, na końcu każdego rekordu bibliograficznego w nawiasach kwadratowych pojawia się data opublikowania; podanie takiej daty jest zgodne z konwencją przyjętą w portalu SAO/NASA Astrophysics Data System (i jego wzbogaconej kopii: „Science Archive Facility” w European Southern Observatory). Zgodnie z konwencją przyjętą we wspomnianych portalach w spisie publikacji uwzględnione zostały także dwie recenzje monografii współautorskiej P. Flina