Marian Pompiliu I Cristescu

Prof. Dr. Marian Pompiliu I Cristescu

Finance & Accounting, Lucian Blaga University of Sibiu, Sibiu, Romania
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Research Focus & Metrics

Academic Career Length

12Years (2015-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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14 November 2022 in Mathematics
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Marian Pompiliu I CristescuMarian Pompiliu I Cristescu
Marian Pompiliu I Cristescu
Raluca Andreea NerișanuRaluca Andreea Nerișanu
Raluca Andreea Nerișanu
Dumitru Alexandru MaraDumitru Alexandru Mara
Dumitru Alexandru Mara
Simona OpreaSimona Oprea
Simona Oprea
(1) Background: Since the current crises that has inevitably impacted the financial market, market prediction has become more crucial than ever. The question of how risk managers can more accurately predict the evolution of their portfolio, while taking into consideration systemic risks brought on by a systemic crisis, is raised by the low rate of success of portfolio risk-management models. Sentiment analysis on natural language sentences can increase the accuracy of market prediction because financial markets are influenced by investor sentiments. Many investors also base their decisions on information taken from newspapers or on their instincts. (2) Methods: In this paper, we aim to highlight how sentiment analysis can improve the accuracy of regression models when predicting the evolution of the opening prices of some selected stocks. We aim to accomplish this by comparing the results and accuracy of two cases of market prediction using regression models with and without market news sentiment analysis. (3) Results: It is shown that the nonlinear autoregression model improves its goodness of fit when sentiment analysis is used as an exogenous factor. Furthermore, the results show that the polynomial autoregressions fit better than the linear ones. (4) Conclusions: Using the sentiment score for market modelling, significant improvements in the performance of linear autoregressions are showcased.

17 March 2020 in Entropy
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SCSebastian Ion Ceptureanu
Sebastian Ion Ceptureanu
Eduard Gabriel CeptureanuEduard Gabriel Ceptureanu
Eduard Gabriel Ceptureanu
Marian Pompiliu I CristescuMarian Pompiliu I Cristescu
Marian Pompiliu I Cristescu
GDGurjeet Dhesi
Gurjeet Dhesi
This paper investigates the effects of social media on entrepreneurial opportunity recognition. Combining the internal and external approaches of opportunity recognition, the study analyzes how social media influences the entrepreneurs in discovering new entrepreneurial opportunities. Structural equation modeling was used in this study, using the variance-based partial least squares (PLS)–structural equation modeling (SEM), on a sample of 354 entrepreneurs. We concluded that social media directly and positively influences entrepreneurial opportunity recognition while entrepreneurial alertness (internal approach) and social networks (external approach) partially mediates its indirect effects on entrepreneurial opportunity recognition. The study contributes to the existing literature by bringing new insights into the entrepreneurial opportunity recognition process by focusing on a poorly represented factor in the literature, social media.

22 February 2023 in IEEE Access
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Simona OpreaSimona Oprea
Simona Oprea
Adela BaraAdela Bara
Adela Bara
AAAnca Ioana Andreescu
Anca Ioana Andreescu
Marian Pompiliu I CristescuMarian Pompiliu I Cristescu
Marian Pompiliu I Cristescu
Digitalization advances in many fields due to its clear advantages and facilities especially in pandemic times when crowds are to be avoided. E-voting is gaining importance as voting using laptops, mobile phones or tablets is more practical. Hence, human counting which leads to unintentional errors or fraud could be eliminated. Furthermore, software applications can reduce the costs of the classic election process and physical infrastructure. In this paper, we propose to identify the most critical specifications of an e-voting application, find a solution for elections in universities and compare our solution with others. The goal is to propose a conceptual architecture using encrypted functions and two stages: voting and validation, separating layers and roles, that is based on blockchain tables and innovative interactions between actors (voters and voting committee) and the two software components (web application and database). For replicability, the conceptual architecture is depicted and formalized using several Unified Modeling Language (UML) diagrams. Furthermore, in order to provide proof of concept, the initial steps in implementing the proposed solution are showcased.

26 February 2024 in IEEE Access
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Adela BaraAdela Bara
Adela Bara
Irina GeorgescuIrina Georgescu
Irina Georgescu
Simona OpreaSimona Oprea
Simona Oprea
Marian Pompiliu I CristescuMarian Pompiliu I Cristescu
Marian Pompiliu I Cristescu
In this paper, we mainly investigate three variables from the price volatility point of view: Brent crude oil, S&P500 and Bitcoin (BTCUSD), aiming to underline the impact of price volatility. Brent crude oil accounts for two-thirds of the oil market. Its price volatility has a significant impact on environmental, transportation, mobility, economic and social aspects that affect sustainability. This paper conducts an extensive examination of the forecasting capabilities of various GARCH (Generalized Autoregressive Conditional Heteroskedasticity) models, identifying the most suitable GARCH model for estimating Value at Risk (VaR) for Brent crude oil price. The assessment of VaR for different GARCH models is carried out using Kupiec’s Probability of Failure (POF) test and Christoffersen’s test. This study leverages Brent crude oil data spanning from 2019 to 2023. Additionally, to prove the robustness of the GARCH models, we further consider the West Texas Intermediate (WTI) and Dubai oil prices that are the dominant in the U.S and Asian market. The investigation identifies the TGARCH(1,1) Skewed Student model as the optimal choice among 9 models considered for VaR estimation. The results show that TGARCH Skewed Student model surpasses the other models in the study, proving its superiority in forecasting Brent crude oil price volatility and facilitating VaR estimation. A VaR of 0.044 with a 95% confidence level means that there is a 95% chance that the portfolio will not lose more than 4.4% of its value. By incorporating skewness in addition to volatility asymmetry, the Skewed GARCH-type models provide a more realistic representation of the underlying return distribution. Furthermore, the most appropriate GARCH-type model for WTI crude oil is EGARCH(1,1) Skewed Student, with a VaR coverage of 0.39. The most appropriate GARCH-type model for Dubai crude oil is TGARCH(1,1) Skewed Student, with a VaR coverage of 0.17. Both WTI oil and Dubai crude oil have a coverage that exceeds 5%, implying a more conservative approach to estimating potential losses. Furthermore, the unidirectional causalities BTCUSD→BRENT and BTCUSD→S&P500 are identified. The results of the current research have practical implications for both importing and exporting countries, policy makers and investors. For companies in the oil sector, VaR informs operational decisions, such as production levels, capital expenditure and inventory management, by providing insights into market risk. Moreover, understanding the risks associated with oil aids in long-term strategic planning.

30 November 2023 in Mathematics
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Marian Pompiliu I CristescuMarian Pompiliu I Cristescu
Marian Pompiliu I Cristescu
Dumitru Alexandru MaraDumitru Alexandru Mara
Dumitru Alexandru Mara
Raluca Andreea NerișanuRaluca Andreea Nerișanu
Raluca Andreea Nerișanu
CLCulda Lia
Culda Lia
IMIonela Maniu
Ionela Maniu
This study investigates the complex interplay between public sentiment, as captured through news titles and descriptions, and the stock prices of three major tech companies: Microsoft (MSFT), Tesla (TSLA), and Apple (AAPL). Leveraging advanced analytical methods including Pearson correlation, wavelet coherence, and regression analysis, this research probes the degree to which stock-price fluctuations can be attributed to the polarity of media sentiment. The methodology combines statistical techniques to assess sentiment’s predictive power for stock opening and closing prices, while wavelet coherence analysis unveils the temporal dynamics of these relationships. The results demonstrate a significant correlation between sentiment polarity and stock prices, with description polarity affecting Microsoft’s opening prices, title polarity influencing Tesla’s opening prices, and a positive impact of title polarity on Apple’s closing prices. However, Tesla’s stock showed no significant coherence, indicating a potential divergence in how sentiment affects stock behavior across companies. The study highlights the importance of sentiment analysis in forecasting stock-market trends, revealing not only direct correlations but also lagged influences on stock prices. Despite its focus on large-cap tech firms, this research provides a foundational understanding of sentiment’s financial implications, suggesting further investigation into smaller firms and other market sectors.

19 October 2023 in Information
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Marian Pompiliu I CristescuMarian Pompiliu I Cristescu
Marian Pompiliu I Cristescu
Dumitru Alexandru MaraDumitru Alexandru Mara
Dumitru Alexandru Mara
CLCulda Lia
Culda Lia
Raluca Andreea NerișanuRaluca Andreea Nerișanu
Raluca Andreea Nerișanu
Adela BaraAdela Bara
Adela Bara
Simona OpreaSimona Oprea
Simona Oprea
This study explores the potential of data science software solutions like Customer Relationship Management Software (CRM) for increasing the revenue generation of businesses. We focused on those businesses in the accommodation and food service sector across the European Union (EU). The investigation is contextualized within the rising trend of data-driven decision-making, examining the potential correlation between data science applications and business revenues. By employing a comprehensive evaluation of Eurostat datasets from 2014 to 2021, we used both univariate and multivariate analyses, assessing the percentage of companies that have e-commerce sales across the EU countries, focusing on the usage of big data analytics from any source and the use of CRM tools for marketing purposes or other activities. Big data utilization showed a clear, positive relationship with enhanced e-commerce sales. However, CRM tools exhibited a dualistic impact: while their use in marketing showed no significant effect on sales, their application in non-marketing functions had negative effects on sales. These findings underscore the potential role of CRM and data science solutions in enhancing business performance in the EU’s accommodation and food service industry.