5,044 research outputs found
Feed-forward and its role in conditional linear optical quantum dynamics
Nonlinear optical quantum gates can be created probabilistically using only
single photon sources, linear optical elements and photon-number resolving
detectors. These gates are heralded but operate with probabilities much less
than one. There is currently a large gap between the performance of the known
circuits and the established upper bounds on their success probabilities. One
possibility for increasing the probability of success of such gates is
feed-forward, where one attempts to correct certain failure events that
occurred in the gate's operation. In this brief report we examine the role of
feed-forward in improving the success probability. In particular, for the
non-linear sign shift gate, we find that in a three-mode implementation with a
single round of feed-forward the optimal average probability of success is
approximately given by p= 0.272. This value is only slightly larger than the
general optimal success probability without feed-forward, P= 0.25.Comment: 4 pages, 3 eps figures, typeset using RevTex4, problems with figures
resolve
Scenarios and enhanced, strategies, Case study The Hague Region, the Netherlands
In the PLUREL Analysis report on The Hague Region (Aalbers et al 2009), the region is described with respect to history, landuse, planning context, actors and their strategies regarding developments in the urban fringe. Three strategies are described in more depth. In the current phase of the research, these strategies are assessed with respect to their performance in governance
Pan-European backcasting exercise, enriched with regional perspective, and including a list of short-term policy options
This deliverable reports on the results of the third and final pan-European stakeholder meeting and secondly, on the enrichment with a Pilot Area and regional perspective. The main emphasis is on backcasting as a means to arrive at long-term strategies and short-term (policy) actions
Geweld in \'n evangelie van liefde: Die Evangelie van Johannes se perspektief op geweld teen Jesus en sy dissipels
Violence in a gospel of love: The perspective of the
Gospel of John on violence against Jesus and his disciples
This article is the first of two articles in which violence in the Gospel of John is discussed. In these articles strong techniques of vilification in the Gospel are pointed out, according to which the status of the opposing group is radically discredited by the Jews on the one hand, and the followers of Jesus on the other hand. In the first article violence and vilification by the Jews, or disciples of Moses against the followers and disciples of Jesus are investigated. It is argued that the central issue of the conflict revolves around the
question: Where is God\'s presence to be found? Among the Jews or among the followers of Jesus? The conflict and violence in John could be understood against the backdrop of this important question.HTS Theological Studies/Teologiese Studies Vol. 64 (4) 2008: pp. 1793-181
Flight-based chemical characterization of biomass burning aerosols within two prescribed burn smoke plumes
Biomass burning represents a major global source of aerosols impacting direct radiative forcing and cloud properties. Thus, the goal of a number of current studies involves developing a better understanding of how the chemical composition and mixing state of biomass burning aerosols evolve during atmospheric aging processes. During the Ice in Clouds Experiment-Layer Clouds (ICE-L) in the fall of 2007, smoke plumes from two small Wyoming Bureau of Land Management prescribed burns were measured by on-line aerosol instrumentation aboard a C-130 aircraft, providing a detailed chemical characterization of the particles. After ~2–4 min of aging, submicron smoke particles, produced primarily from sagebrush combustion, consisted predominantly of organics by mass, but were comprised primarily of internal mixtures of organic carbon, elemental carbon, potassium chloride, and potassium sulfate. Significantly, the fresh biomass burning particles contained minor mass fractions of nitrate and sulfate, suggesting that hygroscopic material is incorporated very near or at the point of emission. The mass fractions of ammonium, sulfate, and nitrate increased with aging up to ~81–88 min and resulted in acidic particles. Decreasing black carbon mass concentrations occurred due to dilution of the plume. Increases in the fraction of oxygenated organic carbon and the presence of dicarboxylic acids, in particular, were observed with aging. Cloud condensation nuclei measurements suggested all particles >100 nm were active at 0.5% water supersaturation in the smoke plumes, confirming the relatively high hygroscopicity of the freshly emitted particles. For immersion/condensation freezing, ice nuclei measurements at −32 °C suggested activation of ~0.03–0.07% of the particles with diameters greater than 500 nm
Field trials and test results of portable DVB-T systems with transmit delay diversity
This paper describes work carried out by Brunel University and Broadreach Systems (UK) to quantify the advantages that can be achieved if Transmit Diversity is applied to systems employing the DVB standard. The techniques investigated can be applied to standard receiver equipment without modification. An extensive and carefully planned field trial was performed during the winter of 2007/2008 in Uxbridge (UK) to validate predictions from theoretical modeling and laboratory simulations. The transmissions were performed in the 730 MHz frequency band with a DVB-T transmitter and a mean power of 18.4dBW. Transmit delay diversity has been observed to deliver significant reception improvement in automotive and indoor- non line of sight situations
From Linear Optical Quantum Computing to Heisenberg-Limited Interferometry
The working principles of linear optical quantum computing are based on
photodetection, namely, projective measurements. The use of photodetection can
provide efficient nonlinear interactions between photons at the single-photon
level, which is technically problematic otherwise. We report an application of
such a technique to prepare quantum correlations as an important resource for
Heisenberg-limited optical interferometry, where the sensitivity of phase
measurements can be improved beyond the usual shot-noise limit. Furthermore,
using such nonlinearities, optical quantum nondemolition measurements can now
be carried out at the single-photon level.Comment: 10 pages, 5 figures; Submitted to a Special Issue of J. Opt. B on
"Fluctuations and Noise in Photonics and Quantum Optics" (Herman Haus
Memorial Issue); v2: minor change
Optimal investment and proportional reinsurance with risk constraint
In this paper, we investigate the problem of maximizing the expected exponential utility for an insurer. In the problem setting, the insurer can invest his/her wealth into the market and he/she can also purchase the proportional reinsurance. To control the risk exposure, we impose a value-at-risk constraint on the portfolio, which results in a constrained stochastic optimal control problem. It is difficult to solve a constrained stochastic optimal control problem by using traditional dynamic programming or Martingale approach. However, for the frequently used exponential utility function, we show that the problem can be simplified significantly using a decomposition approach. The problem is reduced to a deterministic constrained optimal control problem, and then to a finite dimensional optimization problem. To show the effectiveness of the approach proposed, we consider both complete and incomplete markets; the latter arises when the number of risky assets are fewer than the dimension of uncertainty. We also conduct numerical experiments to demonstrate the effect of the risk constraint on the optimal strategy
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