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Federated Learning’s Role in Next-Gen TV Ad Optimization

Computers, Materials & Continua 2025年第1期82卷 675-712页

作者： Gabriela Dobrita Simona-Vasilica Oprea Adela Bâra Department of economic Informatics and Cybernetics Bucharest University of Economic StudiesBucharest010374Romania

In the rapidly evolving landscape of television advertising,optimizing ad schedules to maximize viewer engagement and revenue has become *** methods often operate in silos,limiting the potential insights gained from broader data analysis due to concerns over privacy and data *** article introduces a novel approach that leverages Federated Learning(FL)to enhance TV ad schedule optimization,combining the strengths of local optimization techniques with the power of global Machine Learning(ML)models to uncover actionable insights without compromising data *** combines linear programming for initial ads scheduling optimization with ML—specifically,a K-Nearest Neighbors(KNN)model—for predicting ad spot *** into account the diversity and the difficulty of the ad-scheduling problem,we propose a prescriptivepredictive approach in which first the position of the ads is optimized(using Google’s OR-Tools CP-SAT)and then the scheduled position of all ads will be the result of the optimization ***,this output becomes the target of a predictive task that predicts the position of new entries based on their characteristics ensuring the implementation of the scheduling at large scale(using KNN,Light Gradient Boosting Machine and Random Forest).Furthermore,we explore the integration of FL to enhance predictive accuracy and strategic insight across different broadcasting networks while preserving data *** FL approach resulted in 8750 ads being precisely matched to their optimal category placements,showcasing an alignment with the intended diversity ***,there was a minimal deviation observed,with 1133 ads positioned within a one-category variance from their ideal placement in the original dataset.

关键词： Ad scheduling prescriptive-predictive approach federated learning KNN

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Detecting Malicious Uniform Resource Locators Using an Applied Intelligence Framework

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Computers, Materials & Continua 2024年第6期79卷 3827-3853页

作者： Simona-Vasilica Oprea Adela Bara Department of economic Informatics and Cybernetics Bucharest University of Economic StudiesBucharest010572Romania

The potential of text analytics is revealed by Machine Learning(ML)and Natural Language Processing(NLP)*** this paper,we propose an NLP framework that is applied to multiple datasets to detect malicious Uniform Resource Locators(URLs).Three categories of features,both ML and Deep Learning(DL)algorithms and a ranking schema are included in the proposed *** apply frequency and prediction-based embeddings,such as hash vectorizer,Term Frequency-Inverse Dense Frequency(TF-IDF)and predictors,word to vector-word2vec(continuous bag of words,skip-gram)from Google,to extract features from ***,we apply more state-of-the-art methods to create vectorized features,such as ***,feature engineering that is specific to URL structure is deployed to detect scams and other *** framework assessment,four ranking indicators are weighted:computational time and performance as accuracy,F1 score and type error *** the computational time,we propose a new metric-Feature Building Time(FBT)as the cutting-edge feature builders(like doc2vec or GloVe)require more *** applying the proposed assessment step,the skip-gram algorithm of word2vec surpasses other feature builders in ***,eXtreme Gradient Boost(XGB)outperforms other *** this setup,we attain an accuracy of 99.5%and an F1 score of 0.99.

关键词： Detecting malicious URL classifiers text to feature deep learning ranking algorithms feature building time

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A NECESSARY AND A SUFFICIENT CONDITION FOR THE EXISTENCE OF THE POSITIVE RADIAL SOLUTIONS TO HESSIAN EQUATIONS AND SYSTEMS WITH WEIGHTS

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Acta Mathematica Scientia 2017年第1期37卷 47-57页

作者： Dragos-Patru COVEI Department of Applied Mathematics The Bucharest University of Economic StudiesBucharest 010374Romania

In this article, we consider the existence of positive radial solutions for Hessian equations and systems with weights and we give a necessary condition as well as a sufficient condition for a positive radial solution to be large. The method of proving theorems is essentially based on a successive approximation technique. Our results complete and improve a work published recently by Zhang and Zhou（existence of entire positive k-convex radial solutions to Hessian equations and systems with weights. Applied Mathematics Letters,Volume 50, December 2015, Pages 48–55）.

关键词： existence Keller-Osserman condition k-Hessian equation and system

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How the Investor’s Risk Preferences Influence the Optimal Allocation in a Credibilistic Portfolio Problem

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Journal of Systems Science and Information 2019年第4期10卷 317-329页

作者： Irina GEORGESCU Jani KINNUNEN Department of economic Cybernetics Academy of Economic StudiesBucharestRomania Abo Akademi University Tuomiokirkkotori 3Turku 20500Finland

A classical portfolio theory deals with finding the optimal proportion in which an agent invests a wealth in a risk-free asset and a probabilistic risky asset. Formulating and solving the problem depend on how the risk is represented and how, combined with the utility function defines a notion of expected utility. In this paper the risk is a fuzzy variable and the notion of expected utility is defined in the setting of Liu’s credibility theory. Thus, the portfolio choice problem is formulated as an optimization problem in which the objective function is a credibilistic expected utility. Different approximation calculation formulas for the optimal allocation of the credibilistic risky asset are proved. These formulas contain two types of parameters: Various credibilistic moments associated with fuzzy variables(expected value, variance, skewness and kurtosis) and the risk aversion, prudence and temperance indicators of the utility function.

关键词： prudence temperance credibilistic expected utility

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A three-stage approach for resilience-constrained scheduling of networked microgrids

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Journal of Modern Power Systems and Clean Energy 2019年第4期7卷 705-715页

作者： Saeed TEIMOURZADEH Osman Bulent TOR Mahmut Erkut CEBECI Adela BARA Simona Vasilica OPREA Engineering ProcurementResearch and Analysis(EPRA)Electric Energy Co.AnkaraTurkey Department of economic Informatics and Cybernetics Faculty of CyberneticsStatistics and Economic InformaticsBucharest University of Economic Studies(BUES)BucharestRomania

This paper deals with optimal scheduling of networked microgrids(NMGs)considering resilience *** proposed scheme attempts to mitigate the damaging impacts of electricity interruptions by effectively exploiting NMG capabilities.A three-stage framework is *** Stage 1,the optimal scheduling of NMGs is studied through determining the power transaction between the NMGs and upstream network,the output power of distributed energy resources(DERs),commitment status of conventional DERs as well as demand-side *** Stage 2,the decisions made at Stage 1 are realized considering uncertainties pertaining to renewable generation,market price,power consumption of loads,and unintentional islanding of NMGs from the upstream network and *** 3 deals with uncertainties of unintentional islanding of each MG from the rest of islanded NMGs and *** problem is formulated as a mixed-integer linear programming problem and its effectiveness is assured by simulation studies.

关键词： Networked microgrid(NMG) Distributed energy resource(DER) Power system resilience Point estimate method

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CVaR-based stochastic wind-thermal generation coordination for Turkish electricity market

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Journal of Modern Power Systems and Clean Energy 2019年第5期7卷 1307-1318页

作者： Aycan AYDOGDU Osman Bulent TOR Ali Nezih GUVEN Department of Electrical and Electronics Engineering Middle East Technical UniversityAnkara 06800Turkey The bucharest University of economic studies BucharestRomania

Uncertainties in wind power forecasting,dayahead and imbalance prices for the next day possess a great deal of risks for the profit of generation companies participating in a day-ahead electricity *** companies are exposed to imbalance penalties in the balancing market for unordered mismatches between associated day-ahead power schedule and real-time *** of wind and thermal power plants alleviates the risks raised from wind *** paper proposes a novel optimal coordination strategy by balancing wind power forecasting deviations with thermal units in the Turkish day-ahead electricity *** main focus of this study is to provide an optimal trade-off between the expected profit and the risk under wind uncertainty through conditional value at risk(CVa R)*** problem is formulated as a two-stage mixed-integer stochastic programming problem,where scenario-based wind power approach is used to handle the stochasticity of the wind *** programming approach is utilized to attain the commitment status of thermal *** of the coordination with different day-ahead bidding strategies and trade-off between expected profit and CVa R are examined with comparative scenario studies.

关键词： Conditional value at risk(CVaR) Windthermal coordination Electricity market Wind power Thermal power

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Probability of informed trading during the COVID‑19 pandemic:the case of the Romanian stock market

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Financial Innovation 2023年第1期9卷 889-915页

作者： Cosmin Octavian Cepoi Victor Dragotă Ruxandra Trifan Andreea Iordache Department of Money and Banking and CEFIMO Faculty of Finance and BankingBucharest University of Economic StudiesBucharestRomania Department of Finance and CEFIMO Faculty of Finance and BankingBucharest University of Economic StudiesBucharestRomania Doctoral School of Finance Faculty of Finance and BankingBucharest University of Economic StudiesBucharestRomania

Using data from the bucharest Stock Exchange,we examine the factors influencing the probability of informed trading(PIN)during February—October 2020,a COVID-19 pandemic *** on an unconditional quantile regression approach,we show that PIN exhibit asymmetric dependency with liquidity and trading ***,building a customized database that contains all insider transactions on the bucharest Stock Exchange,we reveal that these types of orders monotonically increase the infor-mation asymmetry from the 50th to the 90th quantile throughout the PIN ***,we bring strong empirical evidence associating the level of information asym-metry to the level of fake news related to the COVID-19 *** novel result suggests that during episodes when the level of PIN is medium to high(between 15 and 50%),any COVID-19 related news classified as misinformation released during the lockdown period,is discouraging informed traders to place buy or sell orders condi-tioned by their private information.

关键词： PIN COVID-19 Market microstructure Insider trading

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Vulnerability to Earthquake Hazard:bucharest Case Study,Romania

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International Journal of Disaster Risk Science 2017年第2期8卷 182-195页

作者： Iuliana Armas Dragos Toma-Danila Radu Ionescu Alexandru Gavris Department of Geomorphology-Pedology-Geomatics Faculty of GeographyUniversity of Bucharest National Institute for Earth Physics Department of Tourism and Geography Bucharest University of Economic Studies

Recent seismic events show that urban areas are increasingly vulnerable to seismic damage,which leads to unprecedented levels of *** are complex systems and as such their analysis requires a good understanding of the interactions between space and the socioeconomic variables characteristic of the inhabitants of urban *** is a clear need to develop and test detailed models that describe the behavior of these interactions under seismic *** article develops an overall vulnerability index to seismic hazard based on a spatial approach applied to bucharest,Romania,the most earthquake-prone capital in the European *** methodology relies on:(1) spatial post-processed socioeconomic data from the2011 Romanian census through multicriteria analysis;and(2) analytical methods(the Improved Displacement Coefficient Method and custom-defined vulnerability functions)for estimating damage patterns,incorporated in a GIS *** computed vulnerability indices for the128 census tracts of the *** sensitivity assessment tested the robustness of spatially identified patterns of building vulnerability in the face of uncertainty in model *** results show that useful seismic vulnerability indices can be obtained through interdisciplinaryapproaches that enhance less detailed datasets,which leads lead to better targeted mitigation efforts.

关键词： bucharest Romania Seismic loss estimation Seismic risk Spatial multicriteria analysis Vulnerability index

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Risk Premiums and Financial Stability

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Journal of Modern Accounting and Auditing 2011年第8期7卷 792-798页

作者： Bogdan Moinescu academy of economic studies Bucharest Romania

The collective revelation of credit institutions as regards the imminence of specific risks materialising, which often follows long periods of underestimating probable losses, can trigger a broad-based financial deleveraging via an overly high upsurge in banks＇ risk premiums vis-a-vis the dynamics of fundamentals underlying loan repayment capability. In this context, this paper seeks to investigate the banking sector＇s internal mechanisms that might bring about a negative spiral of credit risk by building a model for the interaction between the increase of the risk premium and that of net interest income and provisioning rate. Statistical results confirm that a higher risk premium is one of the major determinants of credit default in Romania and its excessive widening could affect financial stability in Romania.

关键词： risk premium financial stability negative spirals of credit risk financial deleveraging CDS (credit default swap) spread

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Knowledge Management and Customer Relationship Management for Accounting Services Companies

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Chinese Business Review 2013年第6期12卷 435-442页

作者： Mirela Elena Nichita Marcel Vulpoi Georgiana Toader bucharest academy of economic studies Bucharest Romania bucharest academy of economic studies Bucharest Romania SC Vulpoi & Toader Management SRL Bucharest Romania

By combining the abilities to respond directly to customer requests and to provide the customer with a highly interactive, customized experience, companies have a greater ability today to establish nurture and sustain long-term customer relationships than ever before. The ultimate goal is to transform these relationships into greater profitability by increasing repeat purchase rates and reducing customer acquisition costs. Customer relationship management （CRM） has a significant potential to leverage an organization＇s performance, but it does not come without a clear sense of destination and typically without pain. For the research methodology we use the database of customers of a Romanian accounting services company Vulpoi ＆ Toader Management SRL, which is an important player in this market. The goal of our paper is to find out the link between knowledge management （KM） and CRM for this company and how these ＂innovations＂ contribute to increasing the value of the business.

关键词： knowledge management (KM) customer relationship management (CRM) accounting profit value ofbusiness

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