Minimax estimation of linear and quadratic functionals on sparsity classes

For the Gaussian sequence model, we obtain non-asymptotic minimax rates of estimation of the linear, quadratic and the L2-norm functionals on classes of sparse vectors and construct optimal estimators that attain these rates. The main object of interest is the class s-sparse vectors for which we also provide completely adaptive estimators (independent of s and of the noise variance) having only logarithmically slower rates than the minimax ones. Furthermore, we obtain the minimax rates on the Lq-balls where 0 < q < 2. This analysis shows that there are, in general, three zones in the rates of convergence that we call the sparse zone, the dense zone and the degenerate zone, while a fourth zone appears for estimation of the quadratic functional. We show that, as opposed to estimation of the vector, the correct logarithmic terms in the optimal rates for the sparse zone scale as log(d/s^2) and not as log(d/s). For the sparse class, the rates of estimation of the linear functional and of the L2-norm have a simple elbow at s = sqrt(d) (boundary between the sparse and the dense zones) and exhibit similar performances, whereas the estimation of the quadratic functional reveals more complex effects and is not possible only on the basis of sparsity described by the sparsity condition on the vector. Finally, we apply our results on estimation of the L2-norm to the problem of testing against sparse alternatives. In particular, we obtain a non-asymptotic analog of the Ingster-Donoho-Jin theory revealing some effects that were not captured by the previous asymptotic analysis.Comment: 32 page

The Impact of QMM on Social Relations in Fort-Dauphin

My interest in this subject began with a general desire to understand how Malagasy society adapts to “outsiders.” We learned throughout the semester about the various external forces that have shaped the culture of the island since the arrival of the first people here thousands of years ago. At first, my ideas were focused more on the experiences of people immigrating to Madagascar. I observed very particular patterns: immigrants of certain ethnicities fill specific socioeconomic niches in specific geographic areas, and with varying reception from the Malagasy community. I came to realize, however, that similar patterns take place even between Malagasy. While many aspects of Malagasy culture are common to all parts of the island, there are definite distinctions between ethnic groups. Regional identity has been an important facet of Malagasy culture throughout history and remains so today

Ocean shrimp report 1979 season

Statewide Pacific ocean shrimp, Pandalus jordani, landings totaled 2,237.7 mt (4,922,857 lb), down 3,745 mt (8,240,386 lb) from the 1978 catch of 5,983.3 mt (13,163,243 lb). The 1979 landings are the lowest since 1976 when 1,545.5 mt (3,400,191 lb) were landed. Area A (Eureka-Crescent City)landings dropped to 1,842.5 mt (4,053,605 lb) from 5,046.3 mt (11,101,895 lb) landed during the previous season. No landings were made in Area B-1 (Fort Bragg). Only 2.0 mt (4,385 lb) were reported caught in Area B-2 (Bodega Bay). Record landings of 393.1 mt (864,867 lb) were made in Area C (Morro Bay-Avila), surpassing the previous record of 90.4 mt (199,000 lb) landed in 1953. In Area A a record 71 vessels, 34 double-rigged and 37 single-rigged, shrimped during the season. Average catch per hour was a low .15 mt (338 lb) and .22 mt (490 1b) for single-rig and double-rig vessels, respectively. In Area C average catch per hour was .23 mt (508 lb) and .42 mt (924 lb) for single-rig and double-rig vessels, respectively. Area A shrimp catches were dominated by 1-year-old shrimp throughout most of the season. The age composition in Area C shifted predominately from 2-year-old shrimp in May and June to predominately 1-year-old shrimp in July, August, October, and November. Area A was closed for one month from July 15 to August 15 because closure criteria of less than .16 mt (350 lb) per hour for two consecutive weeks was met and year class composition exceeded 70% of 1-year-old shrimp. The season was closed October 14 when the catch per hour criterion was exceeded again. (18pp.

WASP-1: A lithium- and metal-rich star with an oversized planet

In this paper we present our results of a comprehensive spectroscopicanalysis of WASP-1, the host star to the exoplanet WASP-1b. We derive T_eff = 6110 +/- 45 K, log g = 4.28 +/- 0.15, and [M/H] = 0.23 +/- 0.08, and also a high abundance of lithium, log n(Li) = 2.91 +/- 0.05. These parameters suggests an age for the system of 1-3 Gyr and a stellar mass of 1.25-1.35 M_sun. This means that WASP-1 has properties very similar to those of HD 149026, the host star for the highest density planet yet detected. Moreover, their planets orbit at comparable distances and receive comparable irradiating fluxes from their host stars. However, despite the similarity of WASP-1 with HD 149026, their planets have strongly different densities. This suggests that gas-giant planet density is not a simple function of host-star metallicity or of radiation environment at ages of ~2 Gyr.Comment: Accepted for publication in MNRAS. 6 pages, 4 figure

Cavity ringdown laser absorption spectroscopy and time-of-flight mass spectroscopy of jet-cooled silver silicides

The cavity ringdown technique has been employed for the first spectroscopic characterization of the AgSi molecule, which is generated in a pulsed laser vaporization plasma reactor. A total of 20 rovibronic bands between 365 and 385 nm have been measured and analyzed to yield molecular properties for the X, B, and C 2Sigma states of AgSi. A time-of-flight mass spectrometer simultaneously monitors species produced in the molecular beam and has provided the first direct evidence for the existence of polyatomic silver silicides. Comparison of the AgSi data to our recent results for the CuSi diatom reveals very similar chemical bonding in the two coinage metal silicides, apparently dominated by covalent interactions

Preparation of the SPS as LHC injector

A major project (SLI) for the preparation the SPS in its role as the final link in the injector chain to the LHC was launched one year ago [1,2]. The major areas of work include the upgrade of the RF and the injection systems, together with the provision of a new extraction channel to serve ring 2 of the LHC. In addition, studies have been made on the ability of the SPS to meet the stringent trans verse and longitudinal beam requirements of the LHC. This has lead to several other programmes of work including upgrades to the beam instrumentation, the transverse damper and the shielding of over 8 00 inter-magnet pumping ports to reduce the impedance of the machine. The planning of the project is influenced by the continued operation of LEP and the proposed new long base-line neutrino facility (NGS). In addition, during the machine upgrades, the SPS must continue to deliver high quality proton beams to the fixed-target experimental community and for an extensive range of experimental detect or test beams. The major areas of work to complete the upgrade will be explained, together with the present status of the project and the future planning

Inside out: Characterising Cybercrimes Committed Inside and Outside the Workplace

This comparison of cybercrime offenders within and outside the workplace reveals they display very different types of offending behaviour, involving different demographics, initiation pathways, and types of offence. The Cambridge Computer Crime Database (CCCD) is a database of open source information about cybercrime arrests and prosecutions in the United Kingdom. This study analyses data from the CCCD spanning nine years, from 1 January 2010 to 31 December 2018. Insiders are more likely to be older, and commit less-technical offences, primarily data and system breaches. They are less likely to offend with others, the offences are less likely to be international in nature, and they are less likely to receive a custodial sentence. Most alleged offenders are men, but women are more likely to offend within their occupation than outside the workplace. Of those that offend in the workplace, the largest group consists of police officers or police staff. This is likely to reflect differences in the type of organisations that pursue criminal action against insiders. We draw on a strain theory framework to argue that these findings accord with different kinds of strain and differing reactions to strain. The data for crimes outside the workplace support a `subcultural' pattern of adaptation to strain, with offenders tending to be younger, male and linked to co-offenders. The findings relating to insiders support an opportunity model of crime, with inter-workplace variation in opportunities, working cultures and sources of strain present in different workplaces.This work was supported by the UK Engineering and Physical Sciences Research Council (EPSRC) [grant EP/M020320/1]

The production of surface-active material by marine phytoplankton cultures

The production of surface-active materials (surfactants) by axenic cultures of five marine diatoms, a dinoflagellate, and a coccolithophorid (all grown in uniform culture conditions) was determined by measuring the volume and stability of the foam produced by shaking...