Grocery retailing in Poland: Structural changes and foreign direct investment

The development of the Polish food retailing sector is very interesting. With the transition from a socialist to a market economy, structural change in the retailing sector has been especially rapid and the new open markets in Poland have attracted foreign investors throughout the economy in general and in the foodretailing sector in particular. This article describes and analyses the major trends in Polish food retailing. It is organised as follows. The structure of food retailing is described and explained in Section 2, first at the store-type level and then at the firm level. How the powerful concentration process in food retailing has affected the marketing chain is also discussed. Inward foreign direct investment (FDI) in Polish food retailing is covered in Section 3. Given the special importance of FDI in the Polish economy during the transition process, an analysis is carried out of the determinants of FDI in retailing within a cross-country dataset and with a particularly detailed look at FDI in Poland. The results are summarised in Section 5. --

Grocery retailing in Germany: Situation, development and pricing strategies

Like many other industrialised countries Germany has experienced a powerful concentration process in food retailing. There are some issues, however, which make Germany a special case in Europe and among industrialised countries in general. This holds true in terms of market structure and concentration, market development and pricing strategies. The market share of hard discounters like Aldi and Lidl has grown continuously in recent decades and the market share of discounters in general has reached a magnitude that is well above that found in other European countries. This has led to robust price competition in German food retailing. Along with this development, it has been very difficult for inward foreign direct investment (FDI) to gain ground in the German food retailing industry. One example was the market entry by Wal-Mart which, given its initial ambitious goals, was not successful. On the other hand, German hard discounters have strongly affected outward FDI by other German food retailers. In the process of expanding into other markets abroad, these companies have had a positive impact on exporting by the German food industry. This article describes and analyses these major trends in German food retailing in detail. It is organised as follows. The structure of food retailing is described and explained in Section 2. Section 3 deals with the importance of inward and outward FDI in German food retailing. It is discussed in both sections how increased concentration in food retailing affects the marketing chain. Price competition is intense in Germany, and studies of food pricing strategies have used scanner data. Therefore a special case study in Section 4 is the analysis of food pricing strategies in Germany based on scanner-data evidence. The analysis shows that the pricing behaviour of food retailers is characterised by the every-day-low-pricing (EDLP) strategies of discounters and the high-lowpricing (HiLo) strategies of their major competitors. The main elements of pricing policies are indicative of firms' market power: repeated price discounts for major food brands, frequent changes of loss leaders, the dominant role of psychological pricing, and a strong price rigidity for all other foods which are not on special offer. --

Exploring the Monero Peer-to-Peer Network

As of September 2019, Monero is the most capitalized privacy- preserving cryptocurrency, and is ranked tenth among all cryptocurren- cies. Monero’s on-chain data privacy guarantees, i.e., how mixins are selected in each transaction, have been extensively studied. However, de- spite Monero’s prominence, the network of peers running Monero clients has not been analyzed. Such analysis is of prime importance, since po- tential vulnerabilities in the peer-to-peer network may lead to attacks on the blockchain’s safety (e.g., by isolating a set of nodes) and on users’ privacy (e.g., tracing transactions flow in the network). This paper provides the first step study on understanding Monero’s peer- to-peer (P2P) network. In particular, we deconstruct Monero’s P2P pro- tocol based on its source code, and develop a toolset to explore Monero’s network, which allows us to infer its topology, size, node distribution, and node connectivity. During our experiments, we collected 510 GB of raw data, from which we extracted 21,678 IP addresses of Monero nodes distributed in 970 autonomous systems. We show that Monero’s network is highly centralized — 13.2% of the nodes collectively maintain 82.86% of the network connections. We have identified approximately 2,758 ac- tive nodes per day, which is 68.7% higher than the number reported by the MoneroHash mining pool. We also identified all concurrent outgoing connections maintained by Monero nodes with very high probability (on average 97.98% for nodes with less than 250 outgoing connections, and 93.79% for nodes with more connections)

Instantaneous Decentralized Poker

We present efficient protocols for amortized secure multiparty computation with penalties and secure cash distribution, of which poker is a prime example. Our protocols have an initial phase where the parties interact with a cryptocurrency network, that then enables them to interact only among themselves over the course of playing many poker games in which money changes hands. The high efficiency of our protocols is achieved by harnessing the power of stateful contracts. Compared to the limited expressive power of Bitcoin scripts, stateful contracts enable richer forms of interaction between standard secure computation and a cryptocurrency. We formalize the stateful contract model and the security notions that our protocols accomplish, and provide proofs using the simulation paradigm. Moreover, we provide a reference implementation in Ethereum/Solidity for the stateful contracts that our protocols are based on. We also adopt our off-chain cash distribution protocols to the special case of stateful duplex micropayment channels, which are of independent interest. In comparison to Bitcoin based payment channels, our duplex channel implementation is more efficient and has additional features

Using rapid scan EPR to improve the detection limit of quantitative EPR by more than one order of magnitude

X band rapid scan EPR was implemented on a commercially available Bruker ELEXSYS E580 spectrometer. Room temperature rapid scan and continuous wave EPR spectra were recorded for amorphous silicon powder samples. By comparing the resulting signal intensities the feasibility of performing quantitative rapid scan EPR is demonstrated. For different hydrogenated amorphous silicon samples, rapid scan EPR results in signal to noise improvements by factors between 10 and 50. Rapid scan EPR is thus capable of improving the detection limit of quantitative EPR by at least one order of magnitude. In addition, we provide a recipe for setting up and calibrating a conventional pulsed and continuous wave EPR spectrometer for rapid scan EP

Inferring short-term volatility indicators from Bitcoin blockchain

In this paper, we study the possibility of inferring early warning indicators (EWIs) for periods of extreme bitcoin price volatility using features obtained from Bitcoin daily transaction graphs. We infer the low-dimensional representations of transaction graphs in the time period from 2012 to 2017 using Bitcoin blockchain, and demonstrate how these representations can be used to predict extreme price volatility events. Our EWI, which is obtained with a non-negative decomposition, contains more predictive information than those obtained with singular value decomposition or scalar value of the total Bitcoin transaction volume

Short Paper: An Exploration of Code Diversity in the Cryptocurrency Landscape

Interest in cryptocurrencies has skyrocketed since their introduction a decade ago, with hundreds of billions of dollars now invested across a landscape of thousands of different cryptocurrencies. While there is significant diversity, there is also a significant number of scams as people seek to exploit the current popularity. In this paper, we seek to identify the extent of innovation in the cryptocurrency landscape using the open-source repositories associated with each one. Among other findings, we observe that while many cryptocurrencies are largely unchanged copies of Bitcoin, the use of Ethereum as a platform has enabled the deployment of cryptocurrencies with more diverse functionalities

Compensating for source directivity in immersive wave experimentation

ISSN:0001-4966ISSN:1520-852

Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal

Measurement of the flavour composition of dijet events in pp collisions at root s=7 TeV with the ATLAS detector

This paper describes a measurement of the flavour composition of dijet events produced in pp collisions at √s=7 TeV using the ATLAS detector. The measurement uses the full 2010 data sample, corresponding to an integrated luminosity of 39 pb−1. Six possible combinations of light, charm and bottom jets are identified in the dijet events, where the jet flavour is defined by the presence of bottom, charm or solely light flavour hadrons in the jet. Kinematic variables, based on the properties of displaced decay vertices and optimised for jet flavour identification, are used in a multidimensional template fit to measure the fractions of these dijet flavour states as functions of the leading jet transverse momentum in the range 40 GeV to 500 GeV and jet rapidity |y|<2.1. The fit results agree with the predictions of leading- and next-to-leading-order calculations, with the exception of the dijet fraction composed of bottom and light flavour jets, which is underestimated by all models at large transverse jet momenta. The ability to identify jets containing two b-hadrons, originating from e.g. gluon splitting, is demonstrated. The difference between bottom jet production rates in leading and subleading jets is consistent with the next-to-leading-order predictions