Audio Event Detection using Weakly Labeled Data

Acoustic event detection is essential for content analysis and description of multimedia recordings. The majority of current literature on the topic learns the detectors through fully-supervised techniques employing strongly labeled data. However, the labels available for majority of multimedia data are generally weak and do not provide sufficient detail for such methods to be employed. In this paper we propose a framework for learning acoustic event detectors using only weakly labeled data. We first show that audio event detection using weak labels can be formulated as an Multiple Instance Learning problem. We then suggest two frameworks for solving multiple-instance learning, one based on support vector machines, and the other on neural networks. The proposed methods can help in removing the time consuming and expensive process of manually annotating data to facilitate fully supervised learning. Moreover, it can not only detect events in a recording but can also provide temporal locations of events in the recording. This helps in obtaining a complete description of the recording and is notable since temporal information was never known in the first place in weakly labeled data.Comment: ACM Multimedia 201

Ursinus College Alumni Journal, Winter 1947

An auspicious beginning for a worthwhile project • President\u27s page • Committees plan new position at college • Status of the war memorial campaign • 964 students enrolled at Ursinus • Miss Moll resumes duties at Ursinus • General Arnold Founders\u27 Day speaker • Three faculty promotions, one appointment announced • New gymnasium nearing completion • Questionnaires outstanding from 900 alumni • Sports: football, soccer, hockey • The shape of things to come? • The attack on illiteracy in British Guiana • News around town • News about ourselves • Faculty members complete laboratory manual • Necrologyhttps://digitalcommons.ursinus.edu/alumnijournal/1029/thumbnail.jp

Gravitational Microlensing of a Reverberating Quasar Broad Line Region - I. Method and Qualitative Results

The kinematics and morphology of the broad emission line region (BELR) of quasars are the subject of significant debate. The two leading methods for constraining BELR properties are microlensing and reverberation mapping. Here we combine these two methods with a study of the microlensing behaviour of the BELR in Q2237+0305, as a change in continuum emission (a "flare") passes through it. Beginning with some generic models of the BELR - sphere, bicones, disk - we slice in velocity and time to produce brightness profiles of the BELR over the duration of the flare. These are numerically microlensed to determine whether microlensing of reverberation mapping provides new information about the properties of BELRs. We describe our method and show images of the models as they are flaring, and the unlensed and lensed spectra that are produced. Qualitative results and a discussion of the spectra are given in this paper, highlighting some effects that could be observed. Our conclusion is that the influence of microlensing, while not strong, can produce significant observable effects that will help in differentiating the properties of BELRs.Comment: 17 pages, 14 low resolution figures, 1 table, accepted for MNRAS. v2: Corrected velocities p16, 8 to 0.08, 9 to 0.0

Ursinus College Alumni Journal, May 1952

President\u27s page • Dr. Paisley honored as layman-of-the-year • Dr. Creese to deliver commencement address • New students enroll for second semester • Dr. Lachman presents bust of Washington • Anne Hughes speaks at Ursinus Color Day • Jeanne Careless is Queen of the May • Summer sessions to open June 9, July 21 • F.B.I. applications • Alumni Day is Saturday, May 31, 1952 • Alumni to entertain seniors at dinner • Nominating committee names candidates • Philadelphia alumni group to reorganize • New York alumni to meet May 7 • Next journal to be mailed November 1952 • Webb enjoys Olympics • Rusty Garlock stars on court for Guam • S. S. Laucks president of York Bar Association • Women\u27s Club enjoys busy spring season • Miss Omwake accepts position at Yale • Bill Daniels returns from work in China • Lt. Col. Bare in Korea • Incidents in the life of a missionary • Sports review: Matmen win 3, lose 4; Alumni asked for Ursinus trophies; Veteran team aims at successful 1952 baseball; Courtmen end season with 7 wins, 10 losses; Badminton team tallies 3 wins, 3 losses; Tennis team faces strong opposition; Mermaids win 3, lose 4; 1952 track prospects look promising; Girls end successful basketball season • Alumni placement at Ursinus • News about ourselves • Necrologyhttps://digitalcommons.ursinus.edu/alumnijournal/1044/thumbnail.jp

About AGN ionization echoes, thermal echoes, and ionization deficits in low redshift Lyman-alpha blobs

We report the discovery of 14 Lyα blobs (LABs) at z ∼ 0.3, existing at least 4–7 billion years later in the Universe than all other LABs known. Their optical diameters are 20–70 kpc, and GALEX data imply Lyα luminosities of (0.4–6.3) × 1043 erg s−1. Contrary to high-z LABs, they live in low-density areas. They are ionized by AGN, suggesting that cold accretion streams as a power source must deplete between z = 2 and 0.3. We also show that transient AGN naturally explain the ionization deficits observed in many LABs. Their Lyα and X-ray fluxes decorrelate below ≲106 years because of the delayed escape of resonantly scattering Lyα photons. High Lyα luminosities do not require currently powerful AGN, independent of obscuration. Chandra X-ray data reveal intrinsically weak AGN, confirming the luminous optical nebulae as impressive ionization echoes. For the first time, we also report mid-infrared thermal echoes from the dusty tori. We conclude that the AGN have faded by three to four orders of magnitude within the last 104–5 years, leaving fossil UV, optical and thermal radiation behind. The host galaxies belong to the group of previously discovered Green Bean galaxies (GBs). Gemini optical imaging reveals smooth spheres, mergers, spectacular outflows and ionization cones. Because of their proximity and high flux densities, GBs are perfect targets to study AGN feedback, mode switching and the Lyα escape. The fully calibrated, co-added optical FITS images are publicly available

Ursinus College Alumni Journal, November 1955

Program for new dormitories underway • Business, the alumnus, and the cost of higher education • Campbell Soup Company establishes fund • James Hirst named to honor society • 18th annual performance announced of the Messiah • Attendance increases in the Ursinus College Evening School • Some notes from the Dean\u27s office • Registrar\u27s report on fall enrollment • Ursinus forum 1955-1956 • Max C. Putney \u2718 author of The Man of Galilee • South Jersey alumni honor Dr. McClure • Binder named Dean at Thiel College • Berks County alumni hold clam bake • Dr. Sherman A. Eger \u2725 describes new operation for high blood pressure • James J. Herron \u2732 elected vice-president of Dun & Bradstreet, Inc. • Alumni eligible for Fulbright scholarships • Ursinus Women\u27s Club • Committee to review alumni constitution • A Fulbrighter in Japan • 1955 Loyalty Fund report • Sick transit - or - She perks no more • Curtain Club presents The Madwoman of Chaillot • Class of \u2756 elects permanent alumni officers • Mrs. Snyder new preceptress at Duryea Hall • G. E. reports on its corporate alumnus program • Regional alumni groups plan student trip • Warren K. Hess \u2731 addresses state school directors • 51\u27ers quartet meet after four years • History art collection • Sports review: Soccer report; Facts about the coaching staff; Alumni varsity basketball game • News about ourselves • Weddings • Births • Necrologyhttps://digitalcommons.ursinus.edu/alumnijournal/1054/thumbnail.jp

A dust-parallax distance of 19 megaparsecs to the supermassive black hole in NGC 4151

The active galaxy NGC 4151 has a crucial role as one of only two active galactic nuclei for which black hole mass measurements based on emission line reverberation mapping can be calibrated against other dynamical methods. Unfortunately, effective calibration requires an accurate distance to NGC 4151, which is currently not available. Recently reported distances range from 4 to 29 megaparsecs (Mpc). Strong peculiar motions make a redshift-based distance very uncertain, and the geometry of the galaxy and its nucleus prohibit accurate measurements using other techniques. Here we report a dust-parallax distance to NGC 4151 of $D_A = 19.0^{+2.4}_{-2.6}$ Mpc. The measurement is based on an adaptation of a geometric method proposed previously using the emission line regions of active galaxies. Since this region is too small for current imaging capabilities, we use instead the ratio of the physical-to-angular sizes of the more extended hot dust emission as determined from time-delays and infrared interferometry. This new distance leads to an approximately 1.4-fold increase in the dynamical black hole mass, implying a corresponding correction to emission line reverberation masses of black holes if they are calibrated against the two objects with additional dynamical masses.Comment: Authors' version of a letter published in Nature (27 November 2014); 8 pages, 5 figures, 1 tabl

The Lick AGN Monitoring Project 2011: Spectroscopic Campaign and Emission-Line Light Curves

In the Spring of 2011 we carried out a 2.5 month reverberation mapping campaign using the 3 m Shane telescope at Lick Observatory, monitoring 15 low-redshift Seyfert 1 galaxies. This paper describes the observations, reductions and measurements, and data products from the spectroscopic campaign. The reduced spectra were fitted with a multicomponent model in order to isolate the contributions of various continuum and emission-line components. We present light curves of broad emission lines and the AGN continuum, and measurements of the broad H-beta line widths in mean and root-mean square (rms) spectra. For the most highly variable AGNs we also measured broad H-beta line widths and velocity centroids from the nightly spectra. In four AGNs exhibiting the highest variability amplitudes, we detect anticorrelations between broad H-beta width and luminosity, demonstrating that the broad-line region "breathes" on short timescales of days to weeks in response to continuum variations. We also find that broad H-beta velocity centroids can undergo substantial changes in response to continuum variations; in NGC 4593 the broad H-beta velocity shifted by ~250 km/s over a one-month duration. This reverberation-induced velocity shift effect is likely to contribute a significant source of confusion noise to binary black hole searches that use multi-epoch quasar spectroscopy to detect binary orbital motion. We also present results from simulations that examine biases that can occur in measurement of broad-line widths from rms spectra due to the contributions of continuum variations and photon-counting noise.Comment: 33 pages, 28 figures, accepted for publication in ApJ Supplement Serie

The Lick AGN Monitoring Project 2011: Reverberation Mapping of Markarian 50

The Lick AGN Monitoring Project 2011 observing campaign was carried out over the course of 11 weeks in Spring 2011. Here we present the first results from this program, a measurement of the broad-line reverberation lag in the Seyfert 1 galaxy Mrk 50. Combining our data with supplemental observations obtained prior to the start of the main observing campaign, our dataset covers a total duration of 4.5 months. During this time, Mrk 50 was highly variable, exhibiting a maximum variability amplitude of a factor of 4 in the U-band continuum and a factor of 2 in the H-beta line. Using standard cross-correlation techniques, we find that H-beta and H-gamma lag the V-band continuum by tau_cen = 10.64(-0.93,+0.82) and 8.43(-1.28,+1.30) days, respectively, while the lag of He II 4686 is unresolved. The H-beta line exhibits a symmetric velocity-resolved reverberation signature with shorter lags in the high-velocity wings than in the line core, consistent with an origin in a broad-line region dominated by orbital motion rather than infall or outflow. Assuming a virial normalization factor of f=5.25, the virial estimate of the black hole mass is (3.2+-0.5)*10^7 solar masses. These observations demonstrate that Mrk 50 is among the most promising nearby active galaxies for detailed investigations of broad-line region structure and dynamics.Comment: Accepted for publication in ApJ Letters. 6 pages, 4 figure

Do reverberation mapping analyses provide an accurate picture of the broad line region?

WM acknowledges the University of Southampton‘s Institute for Complex Systems Simulation and the Engineering and Physical Sciences Research Council for the PhD student that funded his research. CK and NSH acknowledge support by the Science and Technology Facilities Council grant ST/M001326/1. JHM is supported by the Science and Technology Facilities Council under grant ST/N000919/1. KH acknowledges support from STFC grant ST/R000824/1.Reverberation mapping (RM) is a powerful approach for determining the nature of the broad-line region (BLR) in active galactic nuclei. However, inferring physical BLR properties from an observed spectroscopic time series is a difficult inverse problem. Here, we present a blind test of two widely used RM methods: MEMEcho (developed by Horne) and CARAMEL (developed by Pancoast and collaborators). The test data are simulated spectroscopic time series that track the Hα emission line response to an empirical continuum light curve. The underlying BLR model is a rotating, biconical accretion disc wind, and the synthetic spectra are generated via self-consistent ionization and radiative transfer simulations. We generate two mock data sets, representing Seyfert galaxies and QSOs. The Seyfert model produces a largely negative response, which neither method can recover. However, both fail “gracefully”, neither generating spurious results. For the QSO model both CARAMEL and expert interpretation of MEMEchoś output both capture the broadly annular, rotation-dominated nature of the line-forming region, though MEMEcho analysis overestimates its size by 50%, but CARAMEL is unable to distinguish between additional inflow and outflow components. Despite fitting individual spectra well, the CARAMEL velocity-delay maps and RMS line profiles are strongly inconsistent with the input data. Finally, since the Hα line-forming region is rotation dominated, neither method recovers the disc wind nature of the underlying BLR model. Thus considerable care is required when interpreting the results of RM analyses in terms of physical models.PostprintPeer reviewe