Alexander Semenov

Alexander Semenov
University of Florida | UF · Department of Industrial and Systems Engineering

PhD

About

68
Publications
14,697
Reads
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345
Citations
Citations since 2016
51 Research Items
308 Citations
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20162017201820192020202120220204060

Publications

Publications (68)
Article
The “post-Soviet space” consists of countries with a substantial fraction of the world’s population; however, unlike many other regions, its social media network landscape is still somewhat underexplored. This study aims to fill this gap. To this purpose, we use anonymised data on user friendships at VK.com (also known as VKontakte and, informally,...
Article
Full-text available
This paper examines how alternative food networks (AFNs) cultivate engagement on a social media platform. Using the method proposed in Kar and Dwivedi (2020) and Berente et al. (2019), we contribute to theory through combining exploratory text analysis with model testing. Using the theoretical lens of relationship cultivation and social media engag...
Preprint
Full-text available
This paper presents a comprehensive survey of methods which can be utilized to search for solutions to systems of nonlinear equations (SNEs). Our objectives with this survey are to synthesize pertinent literature in this field by presenting a thorough description and analysis of the known methods capable of finding one or many solutions to SNEs, an...
Preprint
Full-text available
This paper presents a comprehensive survey of methods which can be utilized to search for solutions to systems of nonlinear equations (SNEs). Our objectives with this survey are to synthesize pertinent literature in this field by presenting a thorough description and analysis of the known methods capable of finding one or many solutions to SNEs, an...
Article
Background: There is a limited amount of data on the safety profile of the COVID-19 vector vaccine Gam-COVID-Vac (Sputnik V). Previous infodemiology studies showed that social media discourse could be analyzed to assess the most concerning adverse events (AE) caused by drugs. Objective: We aimed to investigate mild AEs of Sputnik V based on a part...
Article
The monitoring of data streams with a network structure have drawn increasing attention due to its wide applications in modern process control. In these applications, high-dimensional sensor nodes are interconnected with an underlying network topology. In such a case, abnormalities occurring to any node may propagate dynamically across the network...
Article
Full-text available
According to recent estimates, one bitcoin transaction consumes as much energy as 1.5 million Visa transactions. Why is bitcoin using so much energy? Most of the energy is used during the bitcoin mining process, which serves at least two significant purposes: a) distributing new cryptocurrency coins to the cryptoeconomy and b) securing the Bitcoin...
Preprint
Full-text available
Determination of price of an artwork is a fundamental problem in cultural economics. In this work we investigate what impact visual characteristics of a painting have on its price. We construct a number of visual features measuring complexity of the painting, its points of interest, segmentation-based features, local color features, and features ba...
Article
Full-text available
We consider a network-based framework for studying causal relationships in financial markets and demonstrate this approach by applying it to the entire U.S. stock market. Directed networks (referred to as “causal market graphs”) are constructed based on publicly available stock prices time series data during 2001–2020, using Granger causality as a...
Preprint
Full-text available
Citizen science and machine learning should be considered for monitoring the coastal and ocean environment due to the scale of threats posed by climate change and the limited resources to fill knowledge gaps. Using data from the annotation activity of citizen scientists in a Swedish marine project, we constructed Deep Neural Network models to predi...
Article
Full-text available
Multipartite entity resolution aims at integrating records from multiple datasets into one entity. We derive a mathematical formulation for a general class of record linkage problems in multipartite entity resolution across many datasets as a combinatorial optimization problem known as the multidimensional assignment problem. As a motivation for ou...
Article
Contextual bandit techniques have recently been used for generating personalized user recommendations in situations where collaborative filtering based algorithms may be inefficient. They are often used in cases when input data are dynamically changing as new users and content items, such as news, constantly change. Contextual bandit methods sequen...
Chapter
We analyzed the Bitcoin difficulty data and noticed that the difficulty has been around the level of \(10^{13}\) for three years (H2 2018–H1 2021). Our calculation showed about \(10^{28}\) hashes have been generated during bitcoin mining around the world for securing the addition of 703,364 blocks to the Bitcoin blockchain. We introduced a concept...
Preprint
Full-text available
We study the recent metaheuristic search algorithm for the multidimensional assignment problem (MAP) using fitness landscape theory. The analyzed algorithm performs a very large-scale neighborhood search on a set of feasible solutions to the problem. We derive properties of the landscape graphs that represent these very large-scale search algorithm...
Preprint
Full-text available
Multipartite entity resolution aims at integrating records from multiple datasets into one entity. We derive a mathematical formulation for a general class of record linkage problems in multipartite entity resolution across many datasets as a combinatorial optimization problem known as the multidimensional assignment problem. As a motivation for ou...
Chapter
Catastrophic and urgent events, such as the COVID-19 pandemic, are known not only to polarize societies and induce selfish, individualistic behavior, but might also motivate altruistic behavior. We have analyzed COVID-19 perception using data collected from the Polish-language Internet from 15.01-30.06.2020, equaling 930,319 tweets. Deploying metho...
Conference Paper
We analyzed the Bitcoin difficulty data and noticed that the difficulty has been around the level of \(10^{13}\) for three years (H2 2018 - H1 2021). Our calculation showed about \(10^{28}\) hashes have been generated during bitcoin mining around the world for securing the addition of 703,364 blocks to the Bitcoin blockchain. We introduced a concep...
Preprint
Background: There is a limited amount of data on the COVID-19 vector vaccine Gam-COVID-Vac (Sputnik V) safety profile. Previous infodemiology studies showed that social media discourse could be analyzed to assess the most concerning adverse events (AE) caused by drugs. Objective: We aimed to investigate mild AEs of Sputnik V based on a participator...
Preprint
BACKGROUND There is limited data on the COVID-19 vector vaccine Gam-COVID-Vac (Sputnik V) safety profile. Previous infodemiology studies showed that social media discourse could be mined to assess the most concerning adverse events (AEs) of drugs. OBJECTIVE We aimed to investigate mild AEs of Sputnik V based on Telegram participatory trial in Russ...
Article
Identifying the native language of a person by their text written in English (L1 identification) plays an important role in such tasks as authorship profiling and identification. With the current proliferation of misinformation in social media, these methods are especially topical. Most studies in this field have focused on the development of super...
Chapter
Full-text available
Blockchain technologies disrupt industries by enabling decentralized and transactional data sharing across a network of untrusted participants, among others. Initial Coin Offerings (ICOs) are a novel form of crowdfunding through which hundreds of blockchain-enabled businesses manage to raise billions of dollars in total only in United States. Howev...
Chapter
Full-text available
Blockchain technologies provide means to develop services that are secure, transparent and efficient by nature. Unsurprisingly, the emerging business opportunities has gained a lot of interest that is realized in form of successful Initial Coin Offerings (ICOs) that are able to raise billions of USD through crowdfunding campaign. In this explorator...
Preprint
Reliable analysis and forecasting of the spread of COVID-19 pandemic and its impacts on global finance and World's economies requires application of econometrically justified and robust methods. At the same time, statistical and econometric analysis of financial and economic markets and of the spread of COVID-19 is complicated by the inherent poten...
Article
Full-text available
With the advent of modern communications systems, much attention has been put on developing methods for securely transferring information between constituents of wireless sensor networks. To this effect, we introduce a mathematical programming formulation for the key management problem, which broadly serves as a mechanism for encrypting communicati...
Article
Full-text available
Advising and mentoring Ph.D. students is an increasingly important aspect of the academic profession. We define and interpret a family of metrics (collectively referred to as “a-indices”) that can potentially be applied to “ranking academic advisors” using the academic genealogical records of scientists, with the emphasis on taking into account not...
Chapter
We analyze a network constructed from tokens developed on Ethereum platform. We collect a large data set of ERC-20 token prices; the total market capitalization of the token set is 50.2 billion \((10^{9})\) US dollars. The token set includes 541 tokens; each one of them has a market capitalization of 1 million US dollars or more. We construct and a...
Chapter
We consider new models of activation/influence propagation in networks based on the concept of double thresholds: a node will “activate” if at least a certain minimum fraction of its neighbors are active and no more than a certain maximum fraction of neighbors are active. These models are more flexible than standard threshold models as they allow t...
Chapter
The aim of this study is to quantitatively assess perception of protests around COVID-19 in Germany from the late July till the end of August 2020 in the Internet media by infodemiological approach. To this end we investigate Google searches, Twitter and Telegram posts, and selection of news articles via EventRegistry. We focus on narratives around...
Article
Full-text available
Abstract The goal of this study is to demonstrate how network science and graph theory tools and concepts can be effectively used for exploring and comparing semantic spaces of word embeddings and lexical databases. Specifically, we construct semantic networks based on word2vec representation of words, which is “learnt” from large text corpora (Goo...
Chapter
We formulate and solve the problem of optimizing the structure of an information propagation network between multiple agents. In a given space of interests (e.g., information on certain targets), each agent is defined by a vector of their desirable information, called filter, and a vector of available information, called source. The agents seek to...
Chapter
Deep neural networks have emerged as an effective machine learning tool successfully applied for many tasks, such as misinformation detection, natural language processing, image recognition, machine translation, etc. Neural networks are often applied to binary or multi-class classification problems. In these settings, cross-entropy is used as a los...
Preprint
With the advent of modern communications systems, much attention has been put on developing methods for securely transferring information between constituents of wireless sensor networks. To this effect, we introduce a mathematical programming formulation for the key management problem, which broadly serves as a mechanism for encrypting communicati...
Article
Full-text available
This paper continues our effort initiated in [9] to study Multicast Communication Networks, modeled as bilevel hierarchical clustering problems, by using mathematical optimization techniques. Given a finite number of nodes, we consider two different models of multicast networks by identifying a certain number of nodes as cluster centers, and at the...
Conference Paper
Most recommender algorithms are designed to suggest relevant items, but suggesting these items does not always result in user satisfaction. Therefore, the efforts in recommender systems recently shifted towards serendipity, but generating serendipitous recommendations is difficult due to the lack of training data. To the best of our knowledge, ther...
Conference Paper
Full-text available
This paper applies structuration theory (ST) and service dominant logic (SDL) as lenses to study different uses of information systems (IS). We argue that resources provided by IS may be combined and reproduced by appropriating them for different purposes than the design purposes of the IS. The study provides empirical data and analysis to showcase...
Article
Background The emerging research on nurturing the growth of online communities posits that it is in part attributed to network effects, wherein every increase in the volume of user-generated content increases the value of the community in the eyes of its potential new members. The recently introduced metric engagement capacity offers a means of qua...
Article
Full-text available
This paper addresses the challenge of strategically maximizing the influence spread in a social network, by exploiting cascade propagators termed “seeds”. It introduces the Seed Activation Scheduling Problem (SASP) that chooses the timing of seed activation under a given budget, over a given time horizon, in the presence/absence of competition. The...
Conference Paper
The purpose of this paper is to explore the participation of main actors in Facebook. The engagement shows different degrees of participation that directly affect the brand image and reputation. This research applies Situational Crisis Communication Theory (SCCT) to interaction in the social media. It provides possibilities for decision makers to m...
Conference Paper
More and more businesses use social media to advertise their services. Such businesses typically maintain online social network accounts and regularly update their pages with advertisement messages describing new products and promotions. One recent trend in such businesses’ activity is to offer incentives to individual users for re-posting the adve...
Conference Paper
Full-text available
Social media sites have appeared during the last 10 years and their use has exploded all over the world. Twitter is a microblogging service that has currently 320 million user profiles and over 100 million daily active users. Many celebrities and leading politicians have a verified profile on Twitter, including Justin Bieber, president Obama, and t...
Article
Does the intensity of a social conflict affect political division? Traditionally, social cleavages are seen as the underlying cause of political conflicts. It is clear, however, that a violent conflict itself can shape partisan, social, and national identities. In this paper, we ask whether social conflicts unite or divide the society by studying t...
Conference Paper
Full-text available
Online social networks have become an essential part of our daily life, and an increasing number of users are using multiple online social networks simultaneously. We hypothesize that the integration of data from multiple social networks could boost the performance of recommender systems. In our study, we perform cross-social network collaborative...
Article
Full-text available
Online pro-health social networks facilitating smoking cessation through web-assisted interventions have flourished in the past decade. In order to properly evaluate and increase the impact of this form of treatment on society, one needs to understand and be able to quantify its reach, as defined within the widely-adopted RE-AIM framework. In the o...
Conference Paper
Full-text available
In this article, we describe an analysis of social network data set that was collected from the Live Journal (LJ) site during autumn 2013. Initially, we collected 114 politically active LJ user profiles, and friends of their friends using the graph search, i.e. those users who are two hops away from those on the original list. A graph was formed fr...
Article
New electronic forms of political communication have become increasingly popular in countries with weak democratic institutions. The effectiveness of these new forms of association in altering political behavior, however, remains uncertain even in developed democratic regimes. This paper investigates connections between regional variation in electo...
Conference Paper
Full-text available
The purpose of this paper is to gain understanding of what factors cause rapid issue spread in social media, to help predict issue growth. The frequency graphics of two issues, Arctic Sunrise and U.S. capitol shooting, were compared to investigate rapidity of spread on Twitter. Next, a qualitative model was applied to explain the differences found....
Article
This paper describes a hierarchical, three-level modelling framework for monitoring social media. Immediate social reality is modelled through the first level of the models. They represent various virtual communities at social media sites and adhere to the social world models of the sites, i.e., the "site ontologies". The second-level model is a te...
Article
This paper describes traces of user activity around a alleged online social network profile of a Boston Marathon bombing suspect, after the tragedy occurred. The analyzed data, collected with the help of an automatic social media monitoring software, includes the perpetrator's page saved at the time the bombing suspects' names were made public, and...
Conference Paper
The disparity between healthcare systems in developed countries and underdeveloped countries is huge, particularly due to the fact that the healthcare infrastructure of former is based on a sophisticated technological infrastructure. Efforts are being made worldwide to bridge this disparity and make healthcare services affordable even to the most r...
Conference Paper
Nowadays, WWW contains a number of social media sites, which are growing rapidly. One of the main features of social media sites is to allow to its users creation and modification of contents of the site utilizing the offered WWW interfaces. Such contents are referred to as user generated contents and their type varies from site to site. Social med...
Article
Social media sites have appeared to the cyber space during the last 5-7 years and have attracted hundreds of millions of users. The sites are often viewed as instances of Web 2.0 technologies and support easy uploading and downloading of user generated contents. This content contains valuable real time information about the state of affairs in vari...
Conference Paper
Full-text available
This paper describes the architecture and a partial implementation of a system designed for the monitoring and analysis of communities at social media sites. The main contribution of the paper is a novel system architecture that facilitates long-term monitoring of diverse social networks existing and emerging at various social media sites. It consi...
Conference Paper
There are over 300 known school shooting cases in the world and over ten known cases where the perpetrator(s) have been prohibited to perform the attack at the last moment or earlier. Interesting from our point of view is that in many cases the perpetrators have expressed their views in social media or on their web page well in advance, and often a...
Article
Full-text available
Surprisingly cruel mass murders and attacks have been witnessed in the educational institutions of the Western world since the 1970s. These are often referred to as 'school shootings'. There have been over 300 known incidents around the world and the number is growing. Social network sites (SNSs) have enabled the perpetrators to express their views...

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