1,573 research outputs found
Dissecting Photometric Redshift for Active Galactic Nucleus Using XMM- and Chandra-COSMOS Samples
In this paper, we release accurate photometric redshifts for 1692 counterparts to Chandra sources in the central square degree of the Cosmic Evolution Survey (COSMOS) field. The availability of a large training set of spectroscopic redshifts that extends to faint magnitudes enabled photometric redshifts comparable to the highest quality results presently available for normal galaxies. We demonstrate that morphologically extended, faint X-ray sources without optical variability are more accurately described by a library of normal galaxies (corrected for emission lines) than by active galactic nucleus (AGN) dominated templates, even if these sources have AGN-like X-ray luminosities. Preselecting the library on the bases of the source properties allowed us to reach an accuracy σ_(Δz/(1+z(spec))~0.015 with a fraction of outliers of 5.8% for the entire Chandra-COSMOS sample. In addition, we release revised photometric redshifts for the 1735 optical counterparts of the XMM-detected sources over the entire 2 deg^2 of COSMOS. For 248 sources, our updated photometric redshift differs from the previous release by Δz > 0.2. These changes are predominantly due to the inclusion of newly available deep H-band photometry (H_(AB) = 24 mag). We illustrate once again the importance of a spectroscopic training sample and how an assumption about the nature of a source together, with the number and the depth of the available bands, influences the accuracy of the photometric redshifts determined for AGN. These considerations should be kept in mind when defining the observational strategies of upcoming large surveys targeting AGNs, such as eROSITA at X-ray energies and the Australian Square Kilometre Array Pathfinder Evolutionary Map of the Universe in the radio band
Performance Study of the Running Times of well known Pattern Matching Algorithms for Signature-based Intrusion Detection Systems
Intrusion detection system (IDS) is the basic component of any network defense scheme. Signature based intrusion detection techniques are widely used in networks for fast response to detect threats. One of the main challenges faced by signature-based IDS is that every signature requires an entry in the database, and so a complete database might contain hundreds or even thousands of entries. Each packet is to be compared with all the entries in the database. This can be highly resource-consuming and doing so will slow down the throughput and making the IDS vulnerable. Since pattern matching computations dominate in the overall performance of a Signature-based IDS, efficient pattern matching algorithms should be used which use minimal computer storage and which minimize the searching response time. In this paper we present a performance study of the running times of different well known pattern matching algorithms using multiple sliding windows approach.
DOI: 10.17762/ijritcc2321-8169.150613
Tablet misoprostol as a cervical priming agent prior to surgical abortion
Background: Every effort to promote effective contraceptive methods as well as emergency contraception is being made, still there would be a need and place for termination of pregnancy. Objective of present study was to evaluate and to know the efficacy and adverse effects of tablet misoprostol 400 micro gram as a cervical priming agent administered either by oral or vaginal route, 3 hours before MTP.Methods: Prospective randomized not blinded study carried out for two years at Government Tertiary care level hospital, OBG Department, Mangalore on 100 women with gestational age up to 12 weeks requesting for surgical abortion.Results: In both the groups there was no significant statistical difference with respect to age (p=0.44), parity and gestational age (p=0.59). With respect to baseline cervical dilatation significant statistical difference was not observed in both the groups. Baseline dilatation of the cervix was 8.0 mm versus 8.2 mm (p value=0.55). Baseline cervical dilatation was ≥7mm in 90% of women when tab misoprostol was given by oral route and 94% with vaginal route. There was no significant statistical difference with respect to side effects (p value>0.05) except nausea (p=0.01) found in both the groups. Gastro Intestinal side effects were more in oral misoprostol group, but it was not statistically significant.Conclusions: Oral route is an effective alternative to vaginal route. Oral route is preferred over vaginal route because women can do self-administration at home and there was no internal examination discomfort
Wess-Zumino Terms in Supersymmetric Gauge Theories
The Wess-Zumino term is constructed for supersymmetric QCD with two colors
and flavors, and is shown to correctly reproduce the anomalous Ward identities.
Supersymmetric QCD is also shown not to have topologically stable skyrmion
solutions because of baryon flat directions, which allow them to unwind. The
generalization of these results to other supersymmetric theories with quantum
modified constraints is discussed.Comment: 4 pages (revtex
Ultrasoft Renormalization in Non-Relativistic QCD
For Non-Relativistic QCD the velocity renormalization group correlates the
renormalization scales for ultrasoft, potential and soft degrees of freedom.
Here we discuss the renormalization of operators by ultrasoft gluons. We show
that renormalization of soft vertices can induce new operators, and also
present a procedure for correctly subtracting divergences in mixed
potential-ultrasoft graphs. Our results affect the running of the
spin-independent potentials in QCD. The change for the NNLL t-tbar cross
section near threshold is very small, being at the 1% level and essentially
independent of the energy. We also discuss implications for analyzing
situations where mv^2 ~ Lambda_QCD.Comment: 31 pages, 11 fig
Ultra-thin titanium nitride films for refractory spectral selectivity
We demonstrate a selectively emitting optical Fabry-P\'erot resonator based
on a few-nm-thin continuous metallic titanium nitride film, separated by a
dielectric spacer from an optically thick titanium nitride back-reflector,
which exhibits excellent stability at 1070 K against chemical degradation,
thin-film instabilities and melting point depression. The structure paves the
way to the design and fabrication of refractory thermal emitters using the
well-established processes known from the field of multilayer and rugate
optical filters. We demonstrate that a few-nanometer thick films of titanium
nitride can be stable under operation at temperatures exceeding 1070 K. This
type of selective emitter provides a means towards near-infrared thermal
emission that could potentially be tailored to the accuracy level known from
rugate optical filters.Comment: 16 pages, 6 figure
Unitarity and the color confinement
We discuss how confinement property of QCD results in the rational
unitarization scheme and how unitarity saturation leads to appearance of a
hadron liquid phase at very high temperatures.Comment: 10 pages, no figire
- …