192 research outputs found
Relay-Linking Models for Prominence and Obsolescence in Evolving Networks
The rate at which nodes in evolving social networks acquire links (friends,
citations) shows complex temporal dynamics. Preferential attachment and link
copying models, while enabling elegant analysis, only capture rich-gets-richer
effects, not aging and decline. Recent aging models are complex and heavily
parameterized; most involve estimating 1-3 parameters per node. These
parameters are intrinsic: they explain decline in terms of events in the past
of the same node, and do not explain, using the network, where the linking
attention might go instead. We argue that traditional characterization of
linking dynamics are insufficient to judge the faithfulness of models. We
propose a new temporal sketch of an evolving graph, and introduce several new
characterizations of a network's temporal dynamics. Then we propose a new
family of frugal aging models with no per-node parameters and only two global
parameters. Our model is based on a surprising inversion or undoing of triangle
completion, where an old node relays a citation to a younger follower in its
immediate vicinity. Despite very few parameters, the new family of models shows
remarkably better fit with real data. Before concluding, we analyze temporal
signatures for various research communities yielding further insights into
their comparative dynamics. To facilitate reproducible research, we shall soon
make all the codes and the processed dataset available in the public domain
Comparative Study of Zinc Oxide Nanostructures Synthesized by Oxidization of Zinc Foil and Zinc Powder
ZnO is one of the most promising semiconductor material in the UV range due to its wide band gap (3.37 eV) and large exciton binding energy (60 meV). So a study of the nature of oxidation of Zn in order to synthesize ZnO is very essential. Here we have tried to study the oxidation behavior of Zinc foil and Zinc powder by oxidizing them in muffle furnace and then carrying out analysis to know if nanostructure is formed or not using SEM, EDX studies along with XRD and DSC/TG. Nanostructures of ZnO were found to grow only at temperatures above 600oC. The surface of the Zn foil is filled with nanostructures of ZnO like nanowires and nanoribbons whereas these structures are not seen in the case of ZnO powder when both the Zn foil and powder were oxidized in the furnace in air in the temperature range 500-600oC. Some indication of probable formation of nanostructure can be seen in sample oxidized at 800o C
Understanding the Impact of Early Citers on Long-Term Scientific Impact
This paper explores an interesting new dimension to the challenging problem
of predicting long-term scientific impact (LTSI) usually measured by the number
of citations accumulated by a paper in the long-term. It is well known that
early citations (within 1-2 years after publication) acquired by a paper
positively affects its LTSI. However, there is no work that investigates if the
set of authors who bring in these early citations to a paper also affect its
LTSI. In this paper, we demonstrate for the first time, the impact of these
authors whom we call early citers (EC) on the LTSI of a paper. Note that this
study of the complex dynamics of EC introduces a brand new paradigm in citation
behavior analysis. Using a massive computer science bibliographic dataset we
identify two distinct categories of EC - we call those authors who have high
overall publication/citation count in the dataset as influential and the rest
of the authors as non-influential. We investigate three characteristic
properties of EC and present an extensive analysis of how each category
correlates with LTSI in terms of these properties. In contrast to popular
perception, we find that influential EC negatively affects LTSI possibly owing
to attention stealing. To motivate this, we present several representative
examples from the dataset. A closer inspection of the collaboration network
reveals that this stealing effect is more profound if an EC is nearer to the
authors of the paper being investigated. As an intuitive use case, we show that
incorporating EC properties in the state-of-the-art supervised citation
prediction models leads to high performance margins. At the closing, we present
an online portal to visualize EC statistics along with the prediction results
for a given query paper
Citation sentence reuse behavior of scientists: A case study on massive bibliographic text dataset of computer science
Our current knowledge of scholarly plagiarism is largely based on the
similarity between full text research articles. In this paper, we propose an
innovative and novel conceptualization of scholarly plagiarism in the form of
reuse of explicit citation sentences in scientific research articles. Note that
while full-text plagiarism is an indicator of a gross-level behavior, copying
of citation sentences is a more nuanced micro-scale phenomenon observed even
for well-known researchers. The current work poses several interesting
questions and attempts to answer them by empirically investigating a large
bibliographic text dataset from computer science containing millions of lines
of citation sentences. In particular, we report evidences of massive copying
behavior. We also present several striking real examples throughout the paper
to showcase widespread adoption of this undesirable practice. In contrast to
the popular perception, we find that copying tendency increases as an author
matures. The copying behavior is reported to exist in all fields of computer
science; however, the theoretical fields indicate more copying than the applied
fields
Eco Beach Cleaner
Trash and litter left on beaches can endanger the life of coastal animals, like turtles and birds, and also damagetourism industries by diminishing the natural beauty of beaches. To solve this problem, most coastal areas employmanual labor, volunteer work, or large zambonini-like machines to pick of trash. However, these operations are veryexpensive and time-consuming. In order to efficiently stop the increasingly negative impact of trash debris on coastalecosystems, forms of mechanized, autonomous trash collection and disposal need to be utilized. Developing a robot that cantransverse sandy terrain, pick up small trash debris, dispose of contained trash debris, and avoid large objects and theocean all while functioning autonomously presents a variety of technical challenges. The invention is predicated upon thelater developed concept of raking or combing the sand to a degree of continuity and thoroughness that will assureremoval of not only larger sized debris, but also the bulk of smaller pieces such as broken glass, nails and the like,without necessitating or involving the removal or displacement with the debris, of any consequential quantitiesof the beach sand itself. This paper present the controlling and monitoring of the solar power device which is capable ofpicking up the miscellaneous litter which accumulates on the beach and collects all the litter after filltering the sand to aself attached trash box
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