346 research outputs found
Multi-dimensional Conversation Analysis across Online Social Networks
With the advance of the Internet, ordinary users have created multiple
personal accounts on online social networks, and interactions among these
social network users have recently been tagged with location information. In
this work, we observe user interactions across two popular online social
networks, Facebook and Twitter, and analyze which factors lead to retweet/like
interactions for tweets/posts. In addition to the named entities, lexical
errors and expressed sentiments in these data items, we also consider the
impact of shared user locations on user interactions. In particular, we show
that geolocations of users can greatly affect which social network post/tweet
will be liked/ retweeted. We believe that the results of our analysis can help
researchers to understand which social network content will have better
visibility.Comment: Datasets will be anonymized and published at:
http://akcora.wordpress.com/2013/12/24/pointer-for-datasets
Risks of Friendships on Social Networks
In this paper, we explore the risks of friends in social networks caused by
their friendship patterns, by using real life social network data and starting
from a previously defined risk model. Particularly, we observe that risks of
friendships can be mined by analyzing users' attitude towards friends of
friends. This allows us to give new insights into friendship and risk dynamics
on social networks.Comment: 10 pages, 8 figures, 3 tables. To Appear in the 2012 IEEE
International Conference on Data Mining (ICDM
Blockchain: A Graph Primer
Bitcoin and its underlying technology Blockchain have become popular in
recent years. Designed to facilitate a secure distributed platform without
central authorities, Blockchain is heralded as a paradigm that will be as
powerful as Big Data, Cloud Computing and Machine learning. Blockchain
incorporates novel ideas from various fields such as public key encryption and
distributed systems. As such, a reader often comes across resources that
explain the Blockchain technology from a certain perspective only, leaving the
reader with more questions than before. We will offer a holistic view on
Blockchain. Starting with a brief history, we will give the building blocks of
Blockchain, and explain their interactions. As graph mining has become a major
part its analysis, we will elaborate on graph theoretical aspects of the
Blockchain technology. We also devote a section to the future of Blockchain and
explain how extensions like Smart Contracts and De-centralized Autonomous
Organizations will function. Without assuming any reader expertise, our aim is
to provide a concise but complete description of the Blockchain technology.Comment: 16 pages, 8 figure
Profiling user interactions on online social networks.
Over the last couple of years, there has been signi_cant research e_ort in mining user behavior on online social networks for applications ranging from sentiment analysis to marketing. In most of those applications, usually a snapshot of user attributes or user relationships are analyzed to build the data mining models, without considering how user attributes and user relationships can be utilized together.
In this thesis, we will describe how user relationships within a social network can be further augmented by information gathered from user generated texts to analyze large scale dynamics of social networks. Speci_cally, we aim at explaining social network interactions by using information gleaned from friendships, pro_les, and status posts of users. Our approach pro_les user interactions in terms of shared similarities among users, and applies the gained knowledge to help users in understanding the inherent reasons, consequences and bene_ts of interacting with other social network users
Profiling user interactions on online social networks.
Over the last couple of years, there has been signi_cant research e_ort in mining user behavior on online social networks for applications ranging from sentiment analysis to marketing. In most of those applications, usually a snapshot of user attributes or user relationships are analyzed to build the data mining models, without considering how user attributes and user relationships can be utilized together.
In this thesis, we will describe how user relationships within a social network can be further augmented by information gathered from user generated texts to analyze large scale dynamics of social networks. Speci_cally, we aim at explaining social network interactions by using information gleaned from friendships, pro_les, and status posts of users. Our approach pro_les user interactions in terms of shared similarities among users, and applies the gained knowledge to help users in understanding the inherent reasons, consequences and bene_ts of interacting with other social network users
Synthesis and Characterization of Diblock Copolymer Templated Iron Oxide Nanoparticles
Templating ordered assemblies of magnetic oxide nanoparticles within self-assembled diblock copolymers of varying morphologies is an important problem with a wide applicability such as in electromagnetics, optical devices, metal catalysts, medicine and biology. In this thesis, the effects of different polymer structures on particle ordering and resultant magnetic properties have been investigated using various microstructure and magnetic characterization tools.
Ring-opening metathesis polymerization (ROMP) of norbornene and functionalized norbornene monomers has been used to synthesize diblock copolymers of narrow polydispersities using Grubbs' catalyst. These block copolymers can be used as templates to form inorganic nanoparticles. In this research, the structural and
physical understanding of the inorganic-copolymer system was studied by small-angle neutron and x-ray scattering techniques and transmission electron microscopy. Synthesis of -FeO nanoparticles has been achieved within novel
block copolymers of (norbornene)-b-(deuterated norbornene dicarboxylic) acid and (norbornene methanol)-(norbornene dicarboxylic acid). The polymer morphologies were controlled by varying the volume fractions of the constituent blocks. The pure norbornene based diblock copolymer morphologies were demonstrated by electron microscopy for the first time. Spherical, cylindrical and lamellar morphologies of these novel diblock copolymers were
reported. The block ratios of the synthesized polymers were determined using gel permeation chromatography - light scattering, elemental analysis and UV-VIS spectroscopy. Solution phase doping
and submersion of thin films in metal salt solutions were employed as metal doping methods and the observed nanoparticle structures were compared to those of the undoped copolymer morphologies. This
project reports on the types of templating structures and dispersion of the nanoparticles. The effects of particle interactions on the microphase separation and magnetic properties were also investigated. The knowledge gained from understanding the templating mechanism in block copolymer / iron oxide
nanocomposites can be applied to other similar systems for a variety of biological and catalyst applications
Tuning the Mechanical Properties in Model Nanocomposites: Influence of the Polymer-Filler Interfacial Interactions
This paper presents a study of the polymer-filler interfacial effects on
filler dispersion and mechanical reinforcement in Polystyrene (PS) / silica
nanocomposites by direct comparison of two model systems: un-grafted and
PS-grafted silica dispersed in PS matrix. The structure of nanoparticles has
been investigated by combining Small Angle Neutron Scattering (SANS)
measurements and Transmission Electronic Microscopic (TEM) images. The
mechanical properties were studied over a wide range of deformation by
plate/plate rheology and uni-axial stretching. At low silica volume fraction,
the particles arrange, for both systems, in small finite size non-connected
aggregates and the materials exhibit a solid-like behavior independent of the
local polymer/fillers interactions suggesting that reinforcement is dominated
by additional long range effects. At high silica volume fraction, a continuous
connected network is created leading to a fast increase of reinforcement whose
amplitude is then directly dependent on the strength of the local
particle/particle interactions and lower with grafting likely due to
deformation of grafted polymer.Comment: Journal Polymer Science (2011
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