3,079 research outputs found
ON THE DIVISOR PRODUCTS AND PROPER DIVISOR PRODUCTS SEQUENCES
Let n be a positive integer, Pd(n) denotes the product of all positive divisors of n, qd(n) denotes the product of all proper divisors of n
A NUMBER THEORETIC FUNCTION AND ITS MEAN VALUE PROPERTY
Let p be a prime, n be any positive integer, a(n,p) denotes the power of p in the factorization of n!
Enhancing Recommendation Interpretability with Tags: A Neural Variational Model
Recommender systems are widely used for assisting consumers finding interested products, and providing suitable explanations for recommendation is particularly important for enhancing consumers’ trust and satisfaction with the system. Tags can be used to annotate different types of items, yet their potential for providing interpretability is not well studied previously. Therefore, it is worthy to study how to leverage tags to enhance recommendation systems in terms of both interpretability and accuracy. This paper proposes a novel model that seamlessly fuse topic model and recommendation model, where the topic model can analyze tags to infer understandable topics, and the recommendation model can conduct accurate and interpretable recommendations based on these topics. We develop variational auto-encoding method to take advantage of neural networks to infer model parameters. Experiments on real-world datasets illustrate that the proposed method can not only achieve great recommendation performance, but also provide interpretability for the recommendation results
Strong Optical and UV Intermediate-Width Emission Lines in the Quasar SDSS J232444.80-094600.3: Dust-Free and Intermediate-Density Gas at the Skin of Dusty Torus ?
Emission lines from the broad emission line region (BELR) and the narrow
emission line region (NELR) of active galactic nuclei (AGNs) are extensively
studied. However, between these two regions emission lines are rarely detected.
We present a detailed analysis of a quasar SDSS J232444.80-094600.3 (SDSS
J23240946), which is remarkable for its strong intermediate-width emission
lines (IELs) with FWHM 1800 \kmps. The IEL component is presented in
different emission lines, including the permitted lines \lya\ 1216,
\civ\ 1549, semiforbidden line \ciii\ 1909, and forbidden
lines \oiii\ 4959, 5007. With the aid of photo-ionization
models, we found that the IELs are produced by gas with a hydrogen density of
, a distance to the central
ionizing source of pc, a covering factor of CF 6\%, and a
dust-to-gas ratio of times of SMC. We suggest that the strong IELs
of this quasar are produced by nearly dust-free and intermediate-density gas
located at the skin of the dusty torus. Such strong IELs, served as a useful
diagnose, can provide an avenue to study the properties of gas between the BELR
and the NELR
Empirical Tm modeling in the region of Guangxi
Abstract:This paper presents three strategies for modeling the regional empirical Tm (the weighted mean temperature of the atmosphere) to obtain more accurate determinations in a regional empirical model that is better adapted to the geographical and climatic characteristics of the applied area. The proposed models utilize data from four radiosonde stations in Guangxi, at Nanning, Guilin, Wuzhou and Baise, over an 11 month period (from Jan. to Nov. of 2011). The experimental results demonstrated the following: (1) there is no significant difference between monthly and annual regression results at each site; (2) it is more reasonable and feasible to use the proposed regional Hybrid model for the area far away from the radiosonde site; (3) from the analysis of the possible temperature conditions, the precision of the proposed regional Hybrid model is higher than that of the well-known Bevis formula and of some other existing models and can reach an accuracy within 1mm for the GPS-derived PWV estimates for the applied region
Identification of a New -ray-emitting narrow-line Seyfert 1 Galaxy, at Redshift
We report on the identification of a new -ray-emitting narrow-line
Seyfert 1 (NLS1) galaxy, SDSS J122222.55+041315.7, which increases the number
of known objects of this remarkable but rare type of active galactic nuclei
(AGN) to seven. Its optical spectrum, obtained in the Sloan Digital Sky
Survey-Baryon Oscillation Spectroscopic Survey, reveals a broad H
emission line with a width (FWHM) of 1734104 km s. This, along with
strong optical Fe II multiplets [] and a weak [O III] emission line, makes the object a typical NLS1. On the other hand, the
source exhibits a high radio brightness temperature, rapid infrared
variability, and a flat X-ray spectrum extending up to 200 keV. It is
associated with a luminous -ray source detected significantly with {\it
Fermi}/LAT. Correlated variability with other wavebands has not yet been
tested. The spectral energy distribution can be well modelled by a one-zone
leptonic jet model. This new member is by far the most distant
-ray-emitting NLS1, at a redshift of .Comment: 5 pages, published on MNRA
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