The preservation, storage, and handling of black-and-white photographic records

The subject of this article is the preservation of processed blackand- white photographic records in libraries. Since silver gelatin photographic films and papers have been around for about a century, and since by far the largest number of black-and-white photographic images are silver gelatin images, knowledge of the properties of these records is extensive. Factors that may affect their stability are, for the most part, well known.published or submitted for publicatio

Deterministic multi-mode photonic device for quantum information processing

We propose the implementation of a light source, which can deterministically generate a rich variety of multi-mode quantum states. The desired states are encoded in the collective population of different ground hyperfine states of an atomic ensemble and converted to multi-mode photonic states by excitation to optically excited levels followed by cooperative spontaneous emission. Among our examples of applications, we demonstrate how two-photon entangled states can be prepared and implemented in a protocol for reference frame free quantum key distribution and how one-dimensional as well as higher-dimensional cluster states can be produced.Comment: 5 pages, 4 figure

Atomic spin squeezing in an optical cavity

We consider squeezing of one component of the collective spin vector of an atomic ensemble inside an optical cavity. The atoms interact with a cavity mode, and the squeezing is obtained by probing the state of the light field that is transmitted through the cavity. Starting from the stochastic master equation, we derive the time evolution of the state of the atoms and the cavity field, and we compute expectation values and variances of the atomic spin components and the quadratures of the cavity mode. The performance of the setup is compared to spin squeezing of atoms by probing of a light field transmitted only once through the sample.Comment: 8 pages, 2 figure

Pricing exotic options using strong convergence properties?

In finance, the strong convergence properties of discretisations of stochastic differential equations (SDEs) are very important for the hedging and valuation of exotic options. In this paper we show how the use of the Milstein scheme can improve the convergence of the multi-level Monte Carlo method, so that the computational cost to achieve an accuracy of O(e) is reduced to O($\epsilon^{−2}$) for a Lipschitz payoff. The Milstein scheme gives first order strong convergence for all 1−dimensional systems (one Wiener process). However, for processes with two or more Wiener processes, such as correlated portfolios and stochastic volatility models, there is no exact solution for the iterated integrals of second order (Lévy area) and the Milstein scheme neglecting the Lévy area gives the same order of convergence as the Euler-Maruyama scheme. The purpose of this paper is to show that if certain conditions are satisfied, we can avoid the calculation of the Lévy area and obtain first convergence order by applying an orthogonal transformation. We demonstrate when the conditions of the 2−Dimensional problem permit this and give an exact solution for the orthogonal transformation. We present examples of pricing exotic options to demonstrate that the use of both the orthogonal Milstein scheme and the Multi-level Monte Carlo give a substantial reduction in the computation cost

How Effective is European Merger Control?

This paper applies a novel methodology to a unique dataset of large concentrations during the period 1990-2002 to assess merger control’s effectiveness. By using data gathered from several sources and employing different evaluation techniques, we analyze the economic effects of the European Commission’s (EC) merger control decisions and distinguish between blockings, clearances with commitments (either behavioral or structural), and outright clearances. We run an event study on merging and rival firms’ stocks to quantify the profitability effects of mergers and merger control decisions. We back up our results and methodology by using alternative measures for the merger’s profitability effects based on balance sheet data and obtain consistent results. Our findings suggest that outright blockings solve the competitive problems generated by the merger. Remedies are not always effective in solving the market power concerns, at least not on average. Nevertheless, both structural (divestitures) and behavioral remedies do help restore effective competition when correctly applied to anticompetitive mergers during the first investigation phase. Yet, they are on the whole ineffective or even detrimental when applied after the second investigation phase. Finally, remedies - especially behavioral ones - seem to constitute a rent transfer from merging firms to rivals when mistakenly applied to pro-competitive mergers

Transport- reaction modeling of marine gas hydrate deposits- global results

We have developed a multi-1D numerical model of gas hydrate formation and dissolution processes in anoxic marine sediments and, by this model, we have estimated the new global gas hydrate inventory (BURWICZ E. B. et al., 2011). The reaction-transport model contains various chemical compounds (solid organic carbon, dissolved methane, inorganic carbon, and sulfates, gas hydrates, and free methane gas). The rates of POC degradation, anaerobic methane oxidation, sulfate reduction, and methanogenesis are kinetically controlled. Gas hydrate stability zone (GHSZ) is defined as a combination of pressure, temperature, and (to a smaller degree) salinity conditions. The lower boundary of the GHSZ is defined as the intersection of gas hydrate and methane gas solubilities. The diffusion equations are solved using a fully-implicit finite-differences method, while all transport processes are resolved by a Semi-Lagrangian scheme. Global input data sets (1°x1° resolution) were compiled from various oceanographic, geological and geophysical sources. The entire model was implemented in Matlab

EU Merger Remedies: A Preliminary Empirical Assessment

Mergers that substantially lessen competition are challenged by antitrust authorities. Instead of blocking anticompetitive transitions straight away, authorities might choose to negotiate with the merging parties and allow the transactions to proceed with modifications that restore or preserve the competition in the involved markets. We study a sample of 167 mergers that were under the European Commission’s scrutiny from 1990 to 2002. We use an event study methodology to identify the potential anticompetitive effects of mergers as well as the remedial provisions on these transactions. Stock market reactions around the day of the merger’s announcement provide information on the first question, whereas the stock market reactions around the commission’s final decision day convey information about the outcome of the bargaining process between the authority and the merging parties. We first classify mergers according to their effects on competition and then we develop hypotheses on the effects that remedies are supposed to achieve depending on the merger’s competitive outcome. We isolate several stylized facts. First, we find that remedies were not always appropriately imposed. Second, the market seems to be able to predict remedies’ effectiveness when applied in phase I. Third, the market also seems able to produce a good prior to phase II’s clearances and prohibitions, but not to remedies. This can be due either to a measurement problem or related to the increased merging firms’ bargaining power during the second phase of the merger review

Is the Event Study Methodology Useful for Merger Analysis? A Comparison of Stock Market and Accounting Data

Using a sample of 167 mergers during the period 1990-2002 involving 544 firms either as merging firms or competitors, we contrast a measure of the merger’s profitability based on event studies with one based on accounting data. We find positive and significant correlations between them when using a long window around the announcement date and, for rivals, in case of anticompetitive mergers