1,589 research outputs found

    The structure of the central disk of NGC 1068: a clumpy disk model

    Get PDF
    NGC 1068 is one of the best studied Seyfert II galaxies, for which the blackhole mass has been determined from the Doppler velocities of water maser. We show that the standard α\alpha-disk model of NGC 1068 gives disk mass between the radii of 0.65 pc and 1.1 pc (the region from which water maser emission is detected) to be about 7x107^7 M_\odot (for α=0.1\alpha=0.1), more than four times the blackhole mass, and a Toomre Q-parameter for the disk is \sim0.001. This disk is therefore highly self-gravitating and is subject to large-amplitude density fluctuations. We conclude that the standard α\alpha-viscosity description for the structure of the accretion disk is invalid for NGC 1068. In this paper we develop a new model for the accretion disk. The disk is considered to be composed of gravitationally bound clumps; accretion in this clumped disk model arises because of gravitational interaction of clumps with each other and the dynamical frictional drag exerted on clumps from the stars in the central region of the galaxy. The clumped disk model provides a self-consistent description of the observations of NGC 1068. The computed temperature and density are within the allowed parameter range for water maser emission, and the rotational velocity in the disk falls off as r0.35r^{-0.35}.Comment: To appear in Ap

    Pengakuan, Pengukuran, Pengungkapan dan Pelaporan Pendapatan Berdasarkan PSAK No.23 pada PT. Pegadaian (Persero)

    Full text link
    Pendapatan adalah penghasilan yang timbul selama dalam aktivitas normal entitas dan dikenal dengan bermacam-macam sebutan yang berbeda seperti penjualan, penghasilan jasa (fees), bunga, dividen dan royalti. Dalam dunia bisnis pendapatan adalah jumlah uang yang diterima oleh Perusahaan dari aktivitasnya, kebanyakan dari penjualan produk atau jasa kepada pelanggan. Penelitian ini dilakukan pada PT. Pegadaian, sebuah Perusahaan yang bergerak dalam bidang jasa keuangan yang kegiatan utamanya adalah menyalurkan uang pinjaman atas dasar hukum gadai. Tujuan penelitian ini adalah untuk menganalisis pengakuan, pengukuran, pengungkapan dan pelaporan pendapatan berdasarkan PSAK No. 23 pada PT. Pegadaian. Metode yang digunakan adalah metode penelitian kualitatif, yaitu analisis deskriptif. Hasil penelitian menunjukkan, pengakuan pendapatan pada PT. Pegadaian diakui berdasarkan akrual basis dinama pendapatan diakui pada saat diperoleh barang atau jasa. Pengkururan pendapatan dicatat sebesar penerimaan kas yang diterima atau sebesar nilai wajar imbalan yang diberikan untuk memperolah pendapatan tersebut. Pengungkapan dan pelaporan pendapatan dilakukan berdasarkan pos masing-masing pendapatan. Pengakuan, pengukuran, pengungkapan dan pelaporan pendapatan pada PT. Pegadaian telah sesuai dengan PSAK No.23. Kata kunci: pendapatan, pengakuan, pengukuran, pengungkapan, pelapora

    Efficient Optimization for Rank-based Loss Functions

    Full text link
    The accuracy of information retrieval systems is often measured using complex loss functions such as the average precision (AP) or the normalized discounted cumulative gain (NDCG). Given a set of positive and negative samples, the parameters of a retrieval system can be estimated by minimizing these loss functions. However, the non-differentiability and non-decomposability of these loss functions does not allow for simple gradient based optimization algorithms. This issue is generally circumvented by either optimizing a structured hinge-loss upper bound to the loss function or by using asymptotic methods like the direct-loss minimization framework. Yet, the high computational complexity of loss-augmented inference, which is necessary for both the frameworks, prohibits its use in large training data sets. To alleviate this deficiency, we present a novel quicksort flavored algorithm for a large class of non-decomposable loss functions. We provide a complete characterization of the loss functions that are amenable to our algorithm, and show that it includes both AP and NDCG based loss functions. Furthermore, we prove that no comparison based algorithm can improve upon the computational complexity of our approach asymptotically. We demonstrate the effectiveness of our approach in the context of optimizing the structured hinge loss upper bound of AP and NDCG loss for learning models for a variety of vision tasks. We show that our approach provides significantly better results than simpler decomposable loss functions, while requiring a comparable training time.Comment: 15 pages, 2 figure

    Comment on “The Thermosolutal Instability of Compressible Hall Plasma I”

    Get PDF

    Prevalence of cardiac autonomic dysfunction in patients with metabolic syndrome: a cross-sectional, observational study

    Get PDF
    Background: Cardiovascular autonomic neuropathy (CAN) is a distinguished disorder associated with diabetes mellitus and metabolic syndrome. The pathogenesis of CAN in patients with metabolic syndrome still remains unclear. This study was undertaken to assess the prevalence of cardiac autonomic dysfunction in patients with metabolic syndrome and to correlate different parameters of metabolic syndrome with cardiac autonomic dysfunction.Methods: In this cross-sectional observational study, total 100 consecutive cases meeting the inclusion criteria and attending the Department of Medicine in Vardhman Mahavir Medical College and Safdarjung Hospital, New Delhi were enrolled. 50 subjects who satisfied the IDF criteria of metabolic syndrome were taken as cases and remaining 50 subjects (age and gender matched) who did not satisfy the IDF criteria were taken as controls. Comparison of categorical variables was made using chi-square or Fisher’s exact test. P-value <0.05 was considered as statistically significant.Results: Majority of study population (i.e., 42%) belonged to the age group of 41-50 years. Overall prevalence of cardiac autonomic dysfunction (CAD) was 25%. Prevalence of CAD among cases and controls was 38% and 12%, respectively. Overall distribution of various parameters like waist circumference, fasting blood glucose, blood pressure, HDL-C and serum triglycerides was assessed in all subjects with respect to CAD. Statistically significant association of these parameters was seen with CAD (p-value ≤0.01).Conclusions: In this study, strong association was found between CAD and central obesity, impaired fasting glucose, high blood pressure and dyslipidemia. Thus, the metabolic disorders are good predictors of CAD

    Applying the Dark Target Aerosol Algorithm with Advanced Himawari Imager Observations During the KORUS-AQ Field Campaign

    Get PDF
    For nearly 2 decades we have been quantitatively observing the Earth's aerosol system from space at one or two times of the day by applying the Dark Target family of algorithms to polar-orbiting satellite sensors, particularly MODIS and VIIRS. With the launch of the Advanced Himawari Imager (AHI) and the Advanced Baseline Imagers (ABIs) into geosynchronous orbits, we have the new ability to expand temporal coverage of the traditional aerosol optical depth (AOD) to resolve the diurnal signature of aerosol loading during daylight hours. The KoreanUnited States Air Quality (KORUS-AQ) campaign taking place in and around the Korean peninsula during MayJune 2016 initiated a special processing of full-disk AHI observations that allowed us to make a preliminary adoption of Dark Target aerosol algorithms to the wavelengths and resolutions of AHI. Here,we describe the adaptation and show retrieval results from AHI for this 2-month period. The AHI-retrieved AOD is collocated in time and space with existing AErosol RObotic NETwork stations across Asia and with collocated Terra and Aqua MODIS retrievals. The new AHI AOD product matches AERONET, and the standard MODIS product does as well, and the agreement between AHI and MODIS retrieved AOD is excellent, as can be expected by maintaining consistency in algorithm architecture and most algorithm assumptions. Furthermore, we show that the new product approximates the AERONET-observed diurnal signature. Examining the diurnal patterns of the new AHI AOD product we find specific areas over land where the diurnal signal is spatially cohesive. For example, in Bangladesh the AOD in-creases by 0.50 from morning to evening, and in northeast China the AOD decreases by 0.25. However, over open ocean the observed diurnal cycle is driven by two artifacts, one associated with solar zenith angles greater than 70t hat may be caused by a radiative transfer model that does not properly represent the spherical Earth and the other artifact associated with the fringes of the 40 degree glint angle mask. This opportunity during KORUS-AQ provides encouragement to move towards an operational Dark Target algorithm for AHI. Future work will need to re-examine masking including snow mask, reevaluate assumed aerosol models for geosynchronous geometry, address the artifacts over the ocean, and investigate size parameter retrieval from the over-ocean algorithm

    The rectus sling to prevent loop colostomy retraction: a case series

    Get PDF
    Diverting stomas are being used increasingly in the management of rectal cancer, particularly with low anterior resection following neoadjuvant therapy. We describe a simple anchorage method for loop colostomy using a rectus fascial sling. This has been used successfully in fifteen patients with no complications or evidence of significant spill over of faecal contents into the efferent loop
    corecore