3,779 research outputs found
Discovering the Impact of Knowledge in Recommender Systems: A Comparative Study
Recommender systems engage user profiles and appropriate filtering techniques
to assist users in finding more relevant information over the large volume of
information. User profiles play an important role in the success of
recommendation process since they model and represent the actual user needs.
However, a comprehensive literature review of recommender systems has
demonstrated no concrete study on the role and impact of knowledge in user
profiling and filtering approache. In this paper, we review the most prominent
recommender systems in the literature and examine the impression of knowledge
extracted from different sources. We then come up with this finding that
semantic information from the user context has substantial impact on the
performance of knowledge based recommender systems. Finally, some new clues for
improvement the knowledge-based profiles have been proposed.Comment: 14 pages, 3 tables; International Journal of Computer Science &
Engineering Survey (IJCSES) Vol.2, No.3, August 201
CHORUS Deliverable 2.1: State of the Art on Multimedia Search Engines
Based on the information provided by European projects and national initiatives related to multimedia search as well as domains experts that participated in the CHORUS Think-thanks and workshops, this document reports on the state of the art related to multimedia content search from, a technical, and socio-economic perspective.
The technical perspective includes an up to date view on content based indexing and retrieval technologies, multimedia search in the context of mobile devices and peer-to-peer networks, and an overview of current evaluation and benchmark inititiatives to measure the performance of multimedia search engines.
From a socio-economic perspective we inventorize the impact and legal consequences of these technical advances and point out future directions of research
Supply Side Optimisation in Online Display Advertising
On the Internet there are publishers (the supply side) who provide free contents (e.g., news) and services (e.g., email) to attract users. Publishers get paid by selling ad displaying opportunities (i.e., impressions) to advertisers. Advertisers then sell products to users who are converted by ads. Better supply side revenue allows more free content and services to be created, thus, benefiting the entire online advertising ecosystem. This thesis addresses several optimisation problems for the supply side. When a publisher creates an ad-supported website, he needs to decide the percentage of ads first. The thesis reports a large-scale empirical study of Internet ad density over past seven years, then presents a model that includes many factors, especially the competition among similar publishers, and gives an optimal dynamic ad density that generates the maximum revenue over time. This study also unveils the tragedy of the commons in online advertising where users' attention has been overgrazed which results in a global sub-optimum. After deciding the ad density, the publisher retrieves ads from various sources, including contracts, ad networks, and ad exchanges. This forms an exploration-exploitation problem when ad sources are typically unknown before trail. This problem is modelled using Partially Observable Markov Decision Process (POMDP), and the exploration efficiency is increased by utilising the correlation of ads. The proposed method reports 23.4% better than the best performing baseline in the real-world data based experiments. Since some ad networks allow (or expect) an input of keywords, the thesis also presents an adaptive keyword extraction system using BM25F algorithm and the multi-armed bandits model. This system has been tested by a domain service provider in crowdsourcing based experiments. If the publisher selects a Real-Time Bidding (RTB) ad source, he can use reserve price to manipulate auctions for better payoff. This thesis proposes a simplified game model that considers the competition between seller and buyer to be one-shot instead of repeated and gives heuristics that can be easily implemented. The model has been evaluated in a production environment and reported 12.3% average increase of revenue. The documentation of a prototype system for reserve price optimisation is also presented in the appendix of the thesis
Opinion mining and sentiment analysis in marketing communications: a science mapping analysis in Web of Science (1998–2018)
Opinion mining and sentiment analysis has become ubiquitous in our society, with
applications in online searching, computer vision, image understanding, artificial intelligence and
marketing communications (MarCom). Within this context, opinion mining and sentiment analysis
in marketing communications (OMSAMC) has a strong role in the development of the field by
allowing us to understand whether people are satisfied or dissatisfied with our service or product
in order to subsequently analyze the strengths and weaknesses of those consumer experiences. To
the best of our knowledge, there is no science mapping analysis covering the research about opinion
mining and sentiment analysis in the MarCom ecosystem. In this study, we perform a science
mapping analysis on the OMSAMC research, in order to provide an overview of the scientific work
during the last two decades in this interdisciplinary area and to show trends that could be the basis
for future developments in the field. This study was carried out using VOSviewer, CitNetExplorer
and InCites based on results from Web of Science (WoS). The results of this analysis show the
evolution of the field, by highlighting the most notable authors, institutions, keywords,
publications, countries, categories and journals.The research was funded by Programa Operativo FEDER Andalucía 2014‐2020, grant number “La
reputación de las organizaciones en una sociedad digital. Elaboración de una Plataforma Inteligente para la
Localización, Identificación y Clasificación de Influenciadores en los Medios Sociales Digitales (UMA18‐
FEDERJA‐148)” and The APC was funded by the same research gran
Data-driven Job Search Engine Using Skills and Company Attribute Filters
According to a report online, more than 200 million unique users search for
jobs online every month. This incredibly large and fast growing demand has
enticed software giants such as Google and Facebook to enter this space, which
was previously dominated by companies such as LinkedIn, Indeed and
CareerBuilder. Recently, Google released their "AI-powered Jobs Search Engine",
"Google For Jobs" while Facebook released "Facebook Jobs" within their
platform. These current job search engines and platforms allow users to search
for jobs based on general narrow filters such as job title, date posted,
experience level, company and salary. However, they have severely limited
filters relating to skill sets such as C++, Python, and Java and company
related attributes such as employee size, revenue, technographics and
micro-industries. These specialized filters can help applicants and companies
connect at a very personalized, relevant and deeper level. In this paper we
present a framework that provides an end-to-end "Data-driven Jobs Search
Engine". In addition, users can also receive potential contacts of recruiters
and senior positions for connection and networking opportunities. The high
level implementation of the framework is described as follows: 1) Collect job
postings data in the United States, 2) Extract meaningful tokens from the
postings data using ETL pipelines, 3) Normalize the data set to link company
names to their specific company websites, 4) Extract and ranking the skill
sets, 5) Link the company names and websites to their respective company level
attributes with the EVERSTRING Company API, 6) Run user-specific search queries
on the database to identify relevant job postings and 7) Rank the job search
results. This framework offers a highly customizable and highly targeted search
experience for end users.Comment: 8 pages, 10 figures, ICDM 201
Real-time Bidding for Online Advertising: Measurement and Analysis
The real-time bidding (RTB), aka programmatic buying, has recently become the
fastest growing area in online advertising. Instead of bulking buying and
inventory-centric buying, RTB mimics stock exchanges and utilises computer
algorithms to automatically buy and sell ads in real-time; It uses per
impression context and targets the ads to specific people based on data about
them, and hence dramatically increases the effectiveness of display
advertising. In this paper, we provide an empirical analysis and measurement of
a production ad exchange. Using the data sampled from both demand and supply
side, we aim to provide first-hand insights into the emerging new impression
selling infrastructure and its bidding behaviours, and help identifying
research and design issues in such systems. From our study, we observed that
periodic patterns occur in various statistics including impressions, clicks,
bids, and conversion rates (both post-view and post-click), which suggest
time-dependent models would be appropriate for capturing the repeated patterns
in RTB. We also found that despite the claimed second price auction, the first
price payment in fact is accounted for 55.4% of total cost due to the
arrangement of the soft floor price. As such, we argue that the setting of soft
floor price in the current RTB systems puts advertisers in a less favourable
position. Furthermore, our analysis on the conversation rates shows that the
current bidding strategy is far less optimal, indicating the significant needs
for optimisation algorithms incorporating the facts such as the temporal
behaviours, the frequency and recency of the ad displays, which have not been
well considered in the past.Comment: Accepted by ADKDD '13 worksho
CHORUS Deliverable 2.2: Second report - identification of multi-disciplinary key issues for gap analysis toward EU multimedia search engines roadmap
After addressing the state-of-the-art during the first year of Chorus and establishing the existing landscape in
multimedia search engines, we have identified and analyzed gaps within European research effort during our second year.
In this period we focused on three directions, notably technological issues, user-centred issues and use-cases and socio-
economic and legal aspects. These were assessed by two central studies: firstly, a concerted vision of functional breakdown
of generic multimedia search engine, and secondly, a representative use-cases descriptions with the related discussion on
requirement for technological challenges. Both studies have been carried out in cooperation and consultation with the
community at large through EC concertation meetings (multimedia search engines cluster), several meetings with our
Think-Tank, presentations in international conferences, and surveys addressed to EU projects coordinators as well as
National initiatives coordinators. Based on the obtained feedback we identified two types of gaps, namely core
technological gaps that involve research challenges, and “enablers”, which are not necessarily technical research
challenges, but have impact on innovation progress. New socio-economic trends are presented as well as emerging legal
challenges
Exploring acceptance of autonomous vehicle policies using KeyBERT and SNA: Targeting engineering students
This study aims to explore user acceptance of Autonomous Vehicle (AV)
policies with improved text-mining methods. Recently, South Korean policymakers
have viewed Autonomous Driving Car (ADC) and Autonomous Driving Robot (ADR) as
next-generation means of transportation that will reduce the cost of
transporting passengers and goods. They support the construction of V2I and V2V
communication infrastructures for ADC and recognize that ADR is equivalent to
pedestrians to promote its deployment into sidewalks. To fill the gap where
end-user acceptance of these policies is not well considered, this study
applied two text-mining methods to the comments of graduate students in the
fields of Industrial, Mechanical, and Electronics-Electrical-Computer. One is
the Co-occurrence Network Analysis (CNA) based on TF-IWF and Dice coefficient,
and the other is the Contextual Semantic Network Analysis (C-SNA) based on both
KeyBERT, which extracts keywords that contextually represent the comments, and
double cosine similarity. The reason for comparing these approaches is to
balance interest not only in the implications for the AV policies but also in
the need to apply quality text mining to this research domain. Significantly,
the limitation of frequency-based text mining, which does not reflect textual
context, and the trade-off of adjusting thresholds in Semantic Network Analysis
(SNA) were considered. As the results of comparing the two approaches, the
C-SNA provided the information necessary to understand users' voices using
fewer nodes and features than the CNA. The users who pre-emptively understood
the AV policies based on their engineering literacy and the given texts
revealed potential risks of the AV accident policies. This study adds
suggestions to manage these risks to support the successful deployment of AVs
on public roads.Comment: 29 pages with 11 figure
情報検索における意味的ギャップの解消 : トピックモデルを用いた先進的画像探索
Tohoku University徳山豪課
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