327 research outputs found
The Nature of the Stable Soft X-ray Emissions in Several Types of Active Galactic Nuclei Observed by Suzaku
To constrain the origin of the soft X-ray excess phenomenon seen in many
active galactic nuclei, the intensity-correlated spectral analysis, developed
by Noda et al. (2011b) for Markarian 509, was applied to wide-band (0.5-45 keV)
Suzaku data of five representative objects with relatively weak reflection
signature. They are the typical bare-nucleus type 1 Seyfert Fairall 9, the
bright and typical type 1.5 Seyfert MCG-2-58-22, 3C382 which is one of the
X-ray brightest broad line radio galaxies, the typical Seyfert-like radio loud
quasar 4C+74.26, and the X-ray brightest radio quiet quasar MR2251-178. In all
of them, soft X-ray intensities in energies below 3 keV were tightly correlated
with that in 3-10 keV, but with significant positive offsets. These offsets,
when calculated in finer energy bands, define a stable soft component in 0.5-3
keV. In each object, this component successfully explained the soft excess
above a power-law fit. These components were interpreted in several alternative
ways, including a thermal Comptonization component which is independent of the
dominant power-law emission. This interpretation, considered physically most
reasonable, is discussed from a viewpoint of Multi-Zone Comptonization, which
was proposed for the black hole binary Cygnus X-1 (Makishima et al. 2008).Comment: 18 pages, 12 figures, 7 table
Performance improvement of JPEG2000 steganography using QIM
This paper presents a modified QIM-JPEG2000 steganography which improves the previous JPEG2000 steganography using quantization index modulation (QIM). Since after-embedding changes on file size and PSNR by the modified QIM-JPEG2000 are smaller than those by the previous QIM-JPEG2000, the modified QIM-JPEG2000 should be more secure than the previous QIM-JPEG2000.4th International Conference on Intelligent Information Hiding and Multimedia Signal Processing (IIH-MSP 2008), 15-17, August, 2008, Harbin, Chin
Lossless data hiding using bit-depth embedding for JPEG2000 compressed bit-stream
We have proposed a reversible information hiding for binary images. In this paper, we presents a lossless data hiding method for JPEG2000 compressed data based on the reversible information hiding. In JPEG2000 compression, wavelet coefficients of an image are quantized,therefore, the least significant bit plane (LSB) can be extracted. The proposed method recovers the quantized wavelet coefficients of cover images from stego images. To realize this, we embed not only secret data and the JBIG2 bit-stream of a part of the LSB plane but also the bit-depth of the quantized coefficients on some code-blocks.Experimental results demonstrate the feasibility of application of the proposed method to image alteration detection for JPEG2000 compressed data.2008 International Conference on Intelligent Information Hiding and Multimedia Signal Processing, 15-17 Aug. 2008, Harbin, Chin
Tissue factor pathway inhibitor-2 suppresses the production of active matrix metalloproteinase-2 and is down-regulated in cells harboring activated ras oncogenes
AbstractA human placenta cDNA expression library was screened for genes inducing flat reversion when transfected into a v-K-ras-transformed NIH3T3 cell line, DT. One such gene was found to encode a Kunitz-type serine protease inhibitor, tissue factor pathway inhibitor-2 (TFPI-2). While the TFPI-2 mRNA can be detected in normal human fibroblasts (MRC-5), it is down-regulated in MRC-5 cells expressing an activated H-ras oncogene and in the human fibrosarcoma cell line, HT1080. Restored expression of the TFPI-2 gene in HT1080 cells resulted in the suppression of matrix invasion activity in vitro with concomitant decrease in the relative amount of active matrix metalloproteinase-2 secreted from the cells. When DT cells were cultured in the presence of conditioned medium and extracellular matrix prepared from TFPI-2-transfected HT1080 cells, increased attachment and flat reversion were observed. These results suggest that TFPI-2 may be required for the maintenance of the integrity of extracellular matrix in normal tissues and its down-regulation as a result of oncogene activation may contribute to the malignant phenotypes of tumor cells
Mathematical aspects of the Digital Annealer's simulated annealing algorithm
The Digital Annealer is a CMOS hardware designed by Fujitsu Laboratories for
high-speed solving of Quadratic Unconstrained Binary Optimization (QUBO)
problems that could be difficult to solve by means of existing general-purpose
computers. In this paper, we present a mathematical description of the
first-generation Digital Annealer's Algorithm from the Markov chain theory
perspective, establish a relationship between its stationary distribution with
the Gibbs-Boltzmann distribution, and provide a necessary and sufficient
condition on its cooling schedule that ensures asymptotic convergence to the
ground states
Improved Characteristics in Organic Thin-Film Solar Cells Based on Conducting Polymer : Fullerene Composites
Fabrication of Organic Photovoltaic Cells with Interpenetrating Heterojunction of Conducting Polymer and C_60 by Spray Method
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