Approximately Truthful Multi-Agent Optimization Using Cloud-Enforced Joint Differential Privacy

Multi-agent coordination problems often require agents to exchange state information in order to reach some collective goal, such as agreement on a final state value. In some cases, it is feasible that opportunistic agents may deceptively report false state values for their own benefit, e.g., to claim a larger portion of shared resources. Motivated by such cases, this paper presents a multi-agent coordination framework which disincentivizes opportunistic misreporting of state information. This paper focuses on multi-agent coordination problems that can be stated as nonlinear programs, with non-separable constraints coupling the agents. In this setting, an opportunistic agent may be tempted to skew the problem's constraints in its favor to reduce its local cost, and this is exactly the behavior we seek to disincentivize. The framework presented uses a primal-dual approach wherein the agents compute primal updates and a centralized cloud computer computes dual updates. All computations performed by the cloud are carried out in a way that enforces joint differential privacy, which adds noise in order to dilute any agent's influence upon the value of its cost function in the problem. We show that this dilution deters agents from intentionally misreporting their states to the cloud, and present bounds on the possible cost reduction an agent can attain through misreporting its state. This work extends our earlier work on incorporating ordinary differential privacy into multi-agent optimization, and we show that this work can be modified to provide a disincentivize for misreporting states to the cloud. Numerical results are presented to demonstrate convergence of the optimization algorithm under joint differential privacy.Comment: 17 pages, 3 figure

Nature of the first excited state of He-4

We study the first excited state of He4 in a microscopic {H3+p,He3+n} cluster model, including H3 and He3 distortions. The phenomenological 1S0 H3+p scattering phase shift is well reproduced. We localize a complex pole of the S-matrix between the H3+p and He3+n thresholds. The corresponding resonance parameters are E_r=93 keV position relative to H3+p, and Gamma=390 keV width. A pole search is also performed in an extended R-matrix method, and a resonance is found with parameters E_r=114 keV and Gamma=392 keV. The R-matrix approach gives several additional poles, some of which may be connected with an enhanced threshold effect.Comment: 13 pages, 2 figure

The bearable lightness of being

How are philosophical questions about what kinds of things there are to be understood and how are they to be answered? This paper defends broadly Fregean answers to these questions. Ontological categories-such as object, property, and relation-are explained in terms of a prior logical categorization of expressions, as singular terms, predicates of varying degree and level, etc. Questions about what kinds of object, property, etc., there are are, on this approach, reduce to questions about truth and logical form: for example, the question whether there are numbers is the question whether there are true atomic statements in which expressions function as singular terms which, if they have reference at all, stand for numbers, and the question whether there are properties of a given type is a question about whether there are meaningful predicates of an appropriate degree and level. This approach is defended against the objection that it must be wrong because makes what there depend on us or our language. Some problems confronting the Fregean approach-including Frege's notorious paradox of the concept horse-are addressed. It is argued that the approach results in a modest and sober deflationary understanding of ontological commitments

8Be Nuclear Data Evaluation

An R-matrix analysis of experimental nuclear data on the reactions 4He(alpha,alpha), 4He(alpha,p), 4He(alpha,d), 7Li(p,alpha), 7Li(p,p), 7Li(p,n), 7Be(n,p), 6Li(d,alpha), 6Li(d,p), 6Li(d,n) and 6Li(d,d), leading to the 8Be intermediate state, has been completed in the last two years. About 4700 data points from 69 experimental references are included. The excitation energy above the 8Be ground state is 25-26 MeV for all reactions except 4He(alpha,alpha) and 7Be(n,p). The data for the reactions 4He(alpha,alpha) and 6Li(d,d) do not fit well, but the other reactions fit with a chi^2/(point) of less than the overall value of 7.9. Most of the 19 resonances found in the R-matrix analysis correspond to resonances formerly known from experiment. Evaluated integrated 4He(alpha,p), 4He(alpha,d), 7Li(p,alpha), 7Li(p,n), 7Be(n,p), 6Li(d,alpha), 6Li(d,p) and 6Li(d,n) reaction cross-sections are presented. Evaluated cross-section and angular dependence files in ENDF format were prepared for the twelve reactions p 7Li, n 7Be, d 6Li -> alpha 4He, p 7Li, n 7Be, d 6Li. Maxwellian averaged temperature-dependent cross-sections in NDI format were prepared for the six reactions 7Li(p,alpha), 7Li(p,n), 7Be(n,p), 6Li(d,alpha), 6Li(d,p) and 6Li(d,n).Comment: Published in proceedings of International Conference on Nuclear Data for Science and Technology (ND2004), Santa Fe, NM, 26 September - 1 October 2004, LaTeX, 4 pages, 8 encapsulated postscript figure

Phase-change materials handbook

Handbook describes relationship between phase-change materials and more conventional thermal control techniques and discusses materials' space and terrestrial applications. Material properties of most promising phase-change materials and purposes and uses of metallic filler materials in phase-change material composites are provided

Who drove the boom in euro-denominated bond issues?

We make use of micro-level data for over 45,000 private bonds issued by over 5000 firms from 22 countries in 1990-2006 to analyze the impact that the launch of the EMU had on the currency denomination of the bond issues. To our knowledge, ours is the first systematic analysis of issue at the micro level. The use of the micro data allows us to distinguish between the response to the advent of the euro by new and seasoned bond issuers, and to condition on other issue characteristics. We find that the impact on new issuers is larger than on seasoned issuers and that most of the increase in the euro-denominated bond issuance was along the "extensive" margin. Insofar as new entrants to the bond market will define the overall currency composition in the long run, these results imply that aggregate studies might be underestimating the euro effect. We also find that to a large extent the increase in euro issuance was "at the expense" of U.S. dollar issuance, suggesting that the euro competes with the U.S. dollar as a currency of choice for international financial transactions.Bond market ; Euro

Towards a simplified taxonomy of Capsella bursa-pastoris (L.) Medik. (Brassicaceae)

Capsella bursa-pastoris (L.) Medik. is a species with a cosmopolitan distribution which shows considerable morphological variation. Numerous authors have recognised widely differing numbers of varieties, microspecies or other infraspecific subdivisions (segregates) of this species. In an attempt to clarify this situation, we grew British material of the species under controlled conditions through to the F) generation to remove environmental variation, and assessed the plants on the basis of a range of morphological criteria, namely leaf shape, capsule size and also length of time taken to flower. Analysis of these characteristics consistently produced four basic groups, which had been previously described. Herbarium specimens could also nearly always be assigned to one of these groups. Limited chromosome counts suggest that two of these groups are diploid and two are tetraploid. We suggest this fourfold division into broad groups reflects the major genetic separations within the species, but that there is also considerable phenotypic plasticity shown by C. bursapastoris in response to factors such as shade or trampling. These four groups appear to differ in their geographic.al distribution in Britain. KEYWORDS: Shepherd's Purse, morphological variation, leaf characters, capsule characters, chromosom