A Mobile Application Recommender System Based on User's Reviwes

, M.Sc. Thesis Sharif University of Technology Mossein, Mobasher (Author) ; Heydarnoori, Abbas (Supervisor)

Abstract

The ever increasing growth of smart phones and their applications have led to the emergence of various platforms, i.e. online stores, for distributing them among users and providing a way for customers and developers to interact with each other. In recent years, these stores have turned into an important form of software repositories, which brought out new challenges for researchers. One of these challenges is the task of searching for suitable applications and providing simple access to them for users. Pervious work has focused on the relationships between users and applications’ contents. Among the shortcomings of these approaches, is not considering users’ reviews of applications and what...

Dwarf galaxies in the Coma cluster - II. Spectroscopic and photometric fundamental planes

, Article Monthly Notices of the Royal Astronomical Society ; Volume 420, Issue 4 , March , 2012 , Pages 2835-2850 ; 00358711 (ISSN) Kourkchi, E ; Khosroshahi, H. G ; Carter, D ; Mobasher, B ; Sharif University of Technology

2012

Abstract

We present a study of the Fundamental Plane (FP) for a sample of 71 dwarf galaxies in the core of the Coma cluster in the magnitude range -21 < M I < -15. Taking advantage of the high-resolution DEIMOS spectrograph on Keck II for measuring the internal velocity dispersion of galaxies and high-resolution imaging of the Hubble Space Telescope (HST)/ACS, which allows an accurate surface brightness modelling, we extend the FP of galaxies to luminosities of ~1 mag fainter than all the previous studies of the FP in the Coma cluster. We find that the scatter about the FP depends on the faint-end luminosity cut-off, such that the scatter increases for fainter galaxies. The residual from the FP...

Dwarf galaxies in the coma cluster - I. Velocity dispersion measurements

, Article Monthly Notices of the Royal Astronomical Society ; Volume 420, Issue 4 , March , 2012 , Pages 2819-2834 ; 00358711 (ISSN) Kourkchi, E ; Khosroshahi, H. G ; Carter, D ; Karick, A. M ; Mármol Queraltó, E ; Chiboucas, K ; Tully, R. B ; Mobasher, B ; Guzmán, R ; Matković, A ; Gruel, N ; Sharif University of Technology

2012

Abstract

We present the study of a large sample of early-type dwarf galaxies in the Coma cluster observed with DEIMOS on the Keck II to determine their internal velocity dispersion. We focus on a subsample of 41 member dwarf elliptical galaxies for which the velocity dispersion can be reliably measured, 26 of which were studied for the first time. The magnitude range of our sample is -21 < M R < -15mag. This paper (Paper I) focuses on the measurement of the velocity dispersion and their error estimates. The measurements were performed using penalized pixel fitting (ppxf) and using the calcium triplet absorption lines. We use Monte Carlo bootstrapping to study various sources of uncertainty in our...