Calibration of the LIGO displacement actuators via laser frequency modulation

We present a frequency modulation technique for calibration of the displacement actuators of the LIGO 4-km-long interferometric gravitational-wave detectors. With the interferometer locked in a single-arm configuration, we modulate the frequency of the laser light, creating an effective length variation that we calibrate by measuring the amplitude of the frequency modulation. By simultaneously driving the voice coil actuators that control the length of the arm cavity, we calibrate the voice coil actuation coefficient with an estimated 1-sigma uncertainty of less than one percent. This technique enables a force-free, single-step actuator calibration using a displacement fiducial that is fundamentally different from those employed in other calibration methods.Comment: 10 pages, 5 figures, submitted to Classical and Quantum Gravit

Household Demand for Broadband Internet Service

As part of the Federal Communications Commission (“FCC”) National Broadband Report to Congress, we have been asked to conduct a survey to help determine consumer valuations of different aspects of broadband Internet service. This report details our methodology, sample and preliminary results. We do not provide policy recommendations. This draft report uses data obtained from a nationwide survey during late December 2009 and early January 2010 to estimate household demand for broadband Internet service. The report combines household data, obtained from choices in a real market and an experimental setting, with a discrete-choice model to estimate the marginal willingness-to-pay (WTP) for improvements in eight Internet service characteristics.

A progress report on using bolometers cooled by adiabatic demagnetization refrigeration

For sensitive detection of astronomical continuum radiation in the 200 micron to 3 mm wavelength range, bolometers are presently the detectors of choice. In order to approach the limits imposed by photon noise in a cryogenically cooled telescope in space, bolometers must be operated at temperatures near 0.1 K. Researchers report progress in building and using bolometers that operate at these temperatures. The most sensitive bolometer had an estimated noise equivalent power (NEP) of 7 x 10(exp 017) W Hz(exp -1/2). Researchers also briefly discuss the durability of paramagnetic salts used to cool the bolometers

Determination of CKM phases through rigid polygons of flavor SU(3) amplitudes

Some new methods for the extraction of CKM phases $\alpha$ and $\gamma$ using flavor SU(3) symmetry have been suggested through the construction of rigid polygons in the complex plane with sides equal to the decay amplitudes of B mesons into two mesons belonging to the light (charmless) pseudoscalar octet. These rigid polygons incorporate all the possible amplitude triangles and, being overdetermined, also serve as consistency checks and in estimating the rates of some decay modes. The same techniques also lead to numerous useful amplitude triangles when octet-singlet mixing has been taken into account and nearly physical $\eta,\eta'$ are used.Comment: A few detailed explanations added, some rearrangement of sections and a few minor changes in notation. 19 pages, 1 PostScript figure, uses psfig.st

Weak Coupling Phase from Decays of Charged B Mesons to πK\pi K and ππ\pi\pi

The theory of $CP$ violation based on phases in weak couplings in the Cabibbo-Kobayashi-Maskawa (CKM) matrix requires the phase $\gamma \equiv {\rm Arg~} V^*_{ub}$ (in a standard convention) to be nonzero. A measurement of $\gamma$ is proposed based on charged $B$ meson decay rates to $\pi^+ K^0$, $\pi^0 K^+$, $\pi^+ \pi^0$, and the charge-conjugate states. The corresponding branching ratios are expected to be of the order of $10^{-5}$. (submitted to Physical Review Letters)Comment: LaTeX, 8 pages, 2 figures (not included, available upon request), TECHNION-PH-94-7, EFI-94-14, UdeM-LPN-TH-94-19

Tooth Contact Shift in Loaded Spiral Bevel Gears

An analytical method is presented to predict the shifts of the contact ellipses of spiral bevel gear teeth under load. The contact ellipse shift is the motion of the tooth contact position from the ideal pitch point to its location under load. The shifts are due to the elastic motions of the gear and pinion supporting shafts and bearings. The calculations include the elastic deflections of the gear shafts and the deflections of the four shaft bearings. The method assumes that the surface curvature of each tooth is constant near the unloaded pitch point. Results from these calculations will help designers reduce transmission weight without seriously reducing transmission performance

Detecting and characterizing lateral phishing at scale

We present the first large-scale characterization of lateral phishing attacks, based on a dataset of 113 million employee-sent emails from 92 enterprise organizations. In a lateral phishing attack, adversaries leverage a compromised enterprise account to send phishing emails to other users, benefit-ting from both the implicit trust and the information in the hijacked user's account. We develop a classifier that finds hundreds of real-world lateral phishing emails, while generating under four false positives per every one-million employee-sent emails. Drawing on the attacks we detect, as well as a corpus of user-reported incidents, we quantify the scale of lateral phishing, identify several thematic content and recipient targeting strategies that attackers follow, illuminate two types of sophisticated behaviors that attackers exhibit, and estimate the success rate of these attacks. Collectively, these results expand our mental models of the 'enterprise attacker' and shed light on the current state of enterprise phishing attacks

What can we learn from antique ornithology?

Ornithology has a venerable history. Worldwide, birds are both culturally important and one of the most salient reminders of the natural world, and beyond their regular appearances in folklore, literature and art they were among the first subjects of natural history from the classical world to the Renaissance. The study of birds remained a fixture of inquiry through the scientific revolution: Philosophical Transactions of the Royal Society, the oldest scientific journal still published, included ornithological method papers in its very first volume (Boyle 1666), and as scientific practice developed ornithological research kept pace. A growing interest in the diversity and systematics of birds ultimately led to the formation of dedicated ornithological societies and journals in the second half of the nineteenth century. First were the Society of German Ornithologists (Deutsche Ornithologen-Gesellschaft) in 1850 and the British Ornithologists’ Union in 1858; their respective journals ‘Journal für Ornithologie’ (now ‘Journal of Ornithology’) and ‘Ibis’ followed in 1853 and 1859. In America, the American Ornithologists’ Union was founded in 1883 with its journal ‘Auk’ beginning the same year, followed by the Wilson Ornithological Society (1886) and Cooper Ornithological Club (1893) and their journals shortly thereafter. The Royal Australasian Ornithologists’ Union (now part of BirdLife Australia) was founded in 1901, along with its journal ‘Emu’. Amazingly, all these publications are still extant, and digital versions of much of their content are now available back to their first issues. In common with other branches of science, ornithological research has exploded in recent decades, and with this plethora of new work, it is tempting to disregard the older corpus of knowledge, under the assumption that it has either been superseded or is too far removed from modern practice to be useful. However, with over 10 000 extant bird species worldwide and the avifauna of many regions still rarely studied, we would encourage the ornithological community to not overlook earlier literature. In this note, we illustrate the potential interest and value of older studies using three diverse articles published in a single journal issue 100 years ago: volume nineteen of Emu

LIGO End-to-End simulation Program

A time-domain simulation program has been developed to provide an accurate description of interferometric gravitational wave detectors. This is being utilized to build a model of LIGO with the aim of aiding in the shakedown and integration of the interferometer subsystems, and ultimately the optimization of detector sensitivity