Bayesian Incentive Compatibility via Fractional Assignments

Very recently, Hartline and Lucier studied single-parameter mechanism design problems in the Bayesian setting. They proposed a black-box reduction that converted Bayesian approximation algorithms into Bayesian-Incentive-Compatible (BIC) mechanisms while preserving social welfare. It remains a major open question if one can find similar reduction in the more important multi-parameter setting. In this paper, we give positive answer to this question when the prior distribution has finite and small support. We propose a black-box reduction for designing BIC multi-parameter mechanisms. The reduction converts any algorithm into an eps-BIC mechanism with only marginal loss in social welfare. As a result, for combinatorial auctions with sub-additive agents we get an eps-BIC mechanism that achieves constant approximation.Comment: 22 pages, 1 figur

Separating the Kinetic and Sorption Parameters of Mixed Chlorinated Solvents in Contact with Granular Iron

Chlorinated solvents and nitroaromatic solvents in drinking-water supplies are an important concern for public health. Granular iron, the most common medium in permeable reactive barriers (PRBs), is very effective at removing organic chemicals, such as chlorinated solvents and nitroaromatic compounds, from groundwater. In an effort to improve barrier designs, studies have been undertaken to examine the iron surface, as well as the reaction kinetics of granular iron. The development of the kinetic iron model (KIM) in 2009, which was derived specifically for PRB settings, made it possible for the first time to assess the simultaneous contributions of sorption and reaction to contaminant degradation rates in iron PRBs, providing a new tool to improve PRB design. This work extended the previous studies that used the KIM by applying the kinetic model to study the effects of iron aging on the reaction kinetics of chlorinated solvents and nitroaromatic solvents. It was found that over time and exposure to water and oxidizing organics, iron tended to lose sorption sites associated with the highest reactivities , but gained reactive sorption capacity to sites with lower reactivity. In the short term, the increasing sorption capacity led to overall faster reaction rates than were observed with new iron. The results also indicated that the KIM parameters were more than simple fitting parameters. As expected, the nitroaromatic compounds tested (4ClNB and 4AcNB) reacted faster than the chlorinated solvents tested (PCE and TCE). Analysis of the data with the KIM indicated the rate differences were due to the surface reaction rate constant, not sorption. This result matched expectations based on earlier studies of these classes of organic chemicals. To test the accuracy of the estimated kinetic and sorption parameters, determined with novel methods in this work, a one dimensional transport model with Langmuir sorption and KIM kinetics was developed to generate synthetic data sets. The model was prepared with the ability to assess intra- and interspecies competition between TCE and PCE in the column experiments. Synthetic data were analyzed with the methods used to interpret the laboratory data and accurate estimates of the input parameters were calculated, validating the methodology. Finally, the activation energy of the 4-chloronitrobenzene reacting with two types of granular iron, Connelly iron and QMP, in batch reactors was obtained to assess the role of mass transfer in controlling the kinetics. Previous work had indicated that mass transfer was not rate controlling with Connelly iron, but QMP was a texturally different form of granular iron that needed further testing. QMP exhibited slower reaction rates compare to Connelly iron. Based on the estimated activation energies (Ea) of the reduction reactions, the reaction mechanism(s) for 4ClNB transformation on Connelly iron and QMP iron were both electron transfer controlled, and the result also suggest that the different transformation rates were therefore related to phases on the solid surface

Finite Temperature Phase Diagram in Rotating Bosonic Optical Lattice

Finite temperature phase boundary between superfluid phase and normal state is analytically derived by studying the stability of normal state in rotating bosonic optical lattice. We also prove that the oscillation behavior of critical hopping matrix directly follows the upper boundary of Hofstadter butterfly as the function of effective magnetic field.Comment: 10 pages, 2 figure

Teaching EFL in Digital Age

Since the beginning of the 21st century, science and technology have been developing and innovating continuously, and people have entered the digital era. Digitalization is an important trend of global economic development. The popularization of digital technology makes it a trend that digital technology can assist EFL teaching. In the current EFL teaching, how to apply advanced digital technology to EFL classroom and how to carry out teaching activities better with digital equipment has become a hot issue for EFL teachers. This study introduces several main auxiliary teaching techniques in the digital age and puts forward some specific strategies for EFL teaching, in order to further improve the teaching level of EFL courses so as to meet students’ personalized development needs

tourrGui: A gWidgets GUI for the Tour to Explore High-Dimensional Data Using Low-Dimensional Projections

This paper describes a graphical user interface (GUI) for the tourr package in R. The tour is a dynamic graphical method for viewing multivariate data. The GUI allows users to interact with a tour in order to explore the data for structures like clustering, outliers, nonlinear dependence. Users can pause the tour, choose a subset of variables, color points by other variables, and switch between several different types of tours

Macrophage migration inhibitory factor (MIF) family in arthropods : Cloning and expression analysis of two MIF and one D-dopachrome tautomerase (DDT) homologues in Mud crabs, Scylla paramamosain

Acknowledgements This research was supported by grants from the National Natural Science Foundation of China (Nos. 31172438 and U1205123), the Natural Science Foundation of Fujian Province (No. 2012J06008 and 201311180002) and the projects-sponsored by SRF. TW received funding from the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland) funded by the Scottish Funding Council (grant reference HR09011) and contributing institutions.Peer reviewedPostprin