University of Bucharest
  • Bucharest, District 5, Romania
Recent publications
Software engineering education is a field in which innovation is constantly taking place, especially in terms of the methods used to achieve the competencies and learning objectives to be taught. The Internet of Things is a relatively new area that offers accessible but complex SE challenges that the authors believe are an excellent example for inclusion in the educational process. Over the course of two academic years, we have explored the integration between SE and the Internet of Things with the additional goal of building an open-source application repository to foster academic research and enhance industrial tools.
Purpose: Sperm DNA fragmentation (SDF) has been associated with male infertility and poor outcomes of assisted reproductive technology (ART). The purpose of this study was to investigate global practices related to the management of elevated SDF in infertile men, summarize the relevant professional society recommendations, and provide expert recommendations for managing this condition. Materials and methods: An online global survey on clinical practices related to SDF was disseminated to reproductive clinicians, according to the CHERRIES checklist criteria. Management protocols for various conditions associated with SDF were captured and compared to the relevant recommendations in professional society guidelines and the appropriate available evidence. Expert recommendations and consensus on the management of infertile men with elevated SDF were then formulated and adapted using the Delphi method. Results: A total of 436 experts from 55 different countries submitted responses. As an initial approach, 79.1% of reproductive experts recommend lifestyle modifications for infertile men with elevated SDF, and 76.9% prescribe empiric antioxidants. Regarding antioxidant duration, 39.3% recommend 4-6 months and 38.1% recommend 3 months. For men with unexplained or idiopathic infertility, and couples experiencing recurrent miscarriages associated with elevated SDF, most respondents refer to ART 6 months after failure of conservative and empiric medical management. Infertile men with clinical varicocele, normal conventional semen parameters, and elevated SDF are offered varicocele repair immediately after diagnosis by 31.4%, and after failure of antioxidants and conservative measures by 40.9%. Sperm selection techniques and testicular sperm extraction are also management options for couples undergoing ART. For most questions, heterogenous practices were demonstrated. Conclusions: This paper presents the results of a large global survey on the management of infertile men with elevated SDF and reveals a lack of consensus among clinicians. Furthermore, it demonstrates the scarcity of professional society guidelines in this regard and attempts to highlight the relevant evidence. Expert recommendations are proposed to help guide clinicians.
Lattice structures are a unique class of architected materials characterized by their array of spatial periodic unit cells. These structures can be designed and engineered to provide a range of desired mechanical properties. Their excellent energy absorption properties make lattice structures well-suited for the design of shoe soles. Leveraging the geometric complexity of additively manufactured parts, the mechanical properties of architected materials, and accurate non-intrusive medical data, this research proposes an algorithmic modeling approach for designing customized lattice shoe soles. By integrating conformal and functionally graded lattices with various unit cell types placed throughout the structure based on plantar pressure data, the flexibility of the sole can be controlled locally in areas with high plantar pressure. This can help reduce ground reaction forces during walking and standing, minimizing negative effects on foot health and increasing comfort for the wearer. We leveraged volumetric modeling techniques for error-free Boolean operations and reliable geometry smoothing. In this manner, our algorithm generates an STL file that contains a watertight mesh, ready to be imported into the slicing software.
We propose to expand the conversation around moral enhancement from direct brain-altering methods to include technological means of modifying the environments and media through which agents can achieve moral improvement. Virtual Reality (VR) based enhancement would not bypass a person’s agency, much less their capacity for reasoned reflection. It would allow agents to critically engage with moral insights occasioned by a technologically mediated intervention. Users would gain access to a vivid ‘experience machine’ that allows for embodied presence and immersion in a virtual world that meaningfully replicates relevant aspects of real life. We explore how VR can train empathy and foster moral growth in complex ways that would be inaccessible even for traditional moral education. Virtual Reality Perspective Taking is a unique medium for making empathy more reflective.
We extend known results on chordal graphs and distance-hereditary graphs to much larger graph classes by using only a common metric property of these graphs. Specifically, a graph is called \(\alpha _i\)-metric (\(i\in \mathcal {N}\)) if it satisfies the following \(\alpha _i\)-metric property for every vertices u, w, v and x: if a shortest path between u and w and a shortest path between x and v share a terminal edge vw, then \(d(u,x)\ge d(u,v) + d(v,x)-i\). Roughly, gluing together any two shortest paths along a common terminal edge may not necessarily result in a shortest path but yields a “near-shortest” path with defect at most i. It is known that \(\alpha _0\)-metric graphs are exactly ptolemaic graphs, and that chordal graphs and distance-hereditary graphs are \(\alpha _i\)-metric for \(i=1\) and \(i=2\), respectively. We show that an additive O(i)-approximation of the radius, of the diameter, and in fact of all vertex eccentricities of an \(\alpha _i\)-metric graph can be computed in total linear time. Our strongest results are obtained for \(\alpha _1\)-metric graphs, for which we prove that a central vertex can be computed in subquadratic time, and even better in linear time for so-called \((\alpha _1,\varDelta )\)-metric graphs (a superclass of chordal graphs and of plane triangulations with inner vertices of degree at least 7). The latter answers a question raised in (Dragan, IPL, 2020). Our algorithms follow from new results on centers and metric intervals of \(\alpha _i\)-metric graphs. In particular, we prove that the diameter of the center is at most \(3i+2\) (at most 3, if \(i=1\)). The latter partly answers a question raised in (Yushmanov & Chepoi, Mathematical Problems in Cybernetics, 1991).
The chapter presents a synthesis of the evolution of technical education in Romania. The first attempts from the beginning of the nineteenth century to found an engineering education are presented, starting with the School of Surveying and Civil Engineers in Moldova (1813) and Wallachia (1818). Later these schools evolved into a French form of engineering schools. Thus, in 1851, the School of Bridges and Roads was founded in Bucharest with a curriculum similar to that of engineering schools in France. This can be considered the first technical university in Romania. The evolution of this school is presented in detail, the transformations undergone in the second half of the nineteenth century due to significant political (establishment of the Kingdom of Romania) and economic (influence of the first industrial revolution on the Romanian economy) transformations. The establishment of the universities of Iasi (1860) and Bucharest (1864) also had a great influence on engineering education, especially in the fields of chemical and electrotechnical engineering. The political changes after the First World War (the union of Transylvania with Romania) radically transformed the Romanian technical education. The National School of Bridges and Roads in Bucharest was transformed into the Polytechnic School of Bucharest (1920), the Politehnica din Timisoara was founded (1920) and the ‘Gheorghe Asachi’ Polytechnic School was founded (1937). This period of higher technical education in Romania can be regarded as a stage of growth, when the level reached could bear comparison to technologically developed countries. After the end of the Second World War the Romanian educational system is changing from the ground up, using the Soviet system as a model. As regards the higher technical education, in 1948, there were three polytechnics in Romania (in Bucharest, Timișoara, and Iași) which trained engineers in all relevant fields. These three universities are developing strongly, expanding the number of faculties covering all fields of engineering. At the same time, new technical universities were established in Cluj Napoca, Galati and Brasov, as well as some specialized technical universities (Technical Military Academy, Technical University of Construction, Institute of Oil and Gas, Coal Institute). At the same time, new universities were founded (Craiova, Sibiu, Constanta, Suceava, Resita, Bacau, Pitesti, Petrosani, Ploiesti) where technical faculties were also included. A new stage in the development of technical education began after the change of political regime in 1989, when state or private universities were established or re-established in the vast majority of large cities in Romania, which also included faculties with a technical profile. An overview of these universities, which also include technical faculties, is presented at the end of the chapter.
This chapter is about biomedical engineering in the country. The opening preamble introduces this realm, a relatively new, multidisciplinary, and multiphysics area of science, education, research, and technology devoted to solving problems in the medicine and biology parts of physics. The following section is devoted to the outstanding forefathers of biomedical engineering and the education and achievements that boded this industry in the country. The third section concerns biomedical schools, technology, and engineering in the interwar decades, from private initiatives to state-ruled education, institutions, and industry. Section four concerns biomedical engineering, education, and research in the post-war and contemporary periods. A birds’ eye view reference timeline presents the organizations, committees, national chapters, and bodies of bioengineering.
The presentation of the history of the Romanian energy system is structured in four stages: before the First World War (1882–1918); between the two World Wars (1918–1950); from the Second World War to 1990; after year 1990. For every stage the text presents separately the components of the energy system: general energy, thermoenergetics, hydroenergetics, nuclear energetics, energy resources, renewable energy and electroenergetics. The thermoelectric power plants the hydroelectric power plants and the high-tension power lines of Romania were made almost entirely by Romanian construction and assembly trusts with Romanian specialists and Romanian workforce. Thermoelectric power plant projects, hydroelectric projects and electrical installation projects were realized by the design institutes of Romanian in collaboration with equipment suppliers and beneficiaries. Energy equipment was mostly imported until 1950, then, for the most part, they were produced by the Romanian industry.
In this Chapter the history of the Romanian automobile industry is presented from its beginnings till today. The first Romanian motor car was the steam car built in 1880 by Dumitru Văsescu during his studies at École Centrale in Paris. On the Romanian territory, the production of automobiles powered by internal combustion engine started in 1909 in Arad, at the Marta factory, branch of the Astra Company (at that time in Austro—Hungarian Empire). A remarkable invention of the Romanian George (Gogu) Constantinescu was the first automatic transmission in the world based on his, sonic torque converter”. In 1924, the engineer Ioan A. Dimitriu patented in Paris the car with dual control, absolute priority worldwide. In 1925, the first Laboratory for the psychological testing of public transport drivers was set up in Bucharest, the 3rd in the world after those established in 1921 in France and Germany. Aurel Persu built the first aerodynamic car worldwide recognized. He presented his invention at the Romanian Academy under the title “The correct aerodynamic car”. The only car factory in Romania between the two WW was the “Ford-Romania” plant, in Bucharest. The first Ford car made here was the “1935” model, Ford V8 Sedan. After the WW II, in 1946, at the “Malaxa” factories, which later became “23 August”, a small car was designed by engineer Petre Carp. In 1947, the “Tractorul” Factory from Brașov, former IAR, starts its production, at first with a single model, IAR 22 (copy of the Hannomag model), a universal type tractor. Over the years, almost 40 models were produced at this factory from the smallest, of 26 HP, for vegetable growing and viticulture, to those of 360 HP, for land improvement works, constructions, embankments etc. In 1954, at the “Steagul Roșu—Red Flag” Plants in Brașov, later called the “Truck Factory”, began the production of the SR 101 truck, followed by SR-131 Carpați and SR-113 Bucegi. In 1971, the first heavy trucks came into production, according to Romanian projects, SR 132 for transport in heavy conditions, AB 45–116 A a dump truck with a payload of 4.5 t, 7AB-1 truck with a payload of 7 t, then (in 1978) the Diesel—electric DAC dump truck of 100 t. In 1956, in Bucharest, the production of buses and trolleybuses started under the brand “Tudor Vladimirescu—TV”, later called “Autobuzul”. There were designed and manufactured numerous types of buses (simple or articulated urban, interurban, coaches), trolleybuses (simple or articulated), minibuses and vans. In 1957, at the Mechanical Plant from Câmpulung—Muscel, in Argeș County, started the manufacturing process of IMS 57, a 100% Romanian off-road car. From 1964 it began the production of M 461 model, which, due to its performances comparable to those of the most prestigious models at that time, had a remarkable success outside Romania. ARO 240, a new off-road car model, was launched in 1966. It will generate the ARO 24 family, with 5 basic models and over 60 constructive variants. On September 6, 1966, the CEO of Régie Nationale des Usines Renault, Pierre Dreyfus, signed in Bucharest the contract granting to the Romanian party the manufacturing license of the Renault 12 model. From 1969, the Colibași plant starts the production of the Dacia 1300 car. In 1979, the Dacia 1310 model was designed starting from this first variant; it underwent numerous re-stylings and was produced until 2004. In 1976, the Romanian—French Joint Company OLTCIT S.A. was established, aiming at the manufacture and sale of small city cars. From the 29th of September 1999, Renault became the majority owner of SC AUTOMOBILE DACIA SA. On June the 2nd, 2004, Dacia Logan was the first law cost car launched in Paris at a price of only 5000 Euros. The best-selling model of the Dacia brand on the Western market was Sandero (2008). In 2010, Dacia presented the first SUV in the history of the brand—the Duster model. In 2016, the Easy-R robotic transmission was introduced on the Logan and Sandero models while in the spring of 2017, the Duster 4 × 2 model equipped with the EDC dual-clutch automatic transmission was launched. On September the 12th, 2007, Ford Motor Company acquired SC Automobile Craiova S.A. The production of Ford B-Max, the first European motor car equipped with an advanced connectivity system—SYNC, with voice commands in several languages and with an emergency assistance function, started in Craiova, in 2012. At the beginning of October 2017, began the production of the SUV model “Ford EcoSport”. The Renault Group set up Renault Technologie Roumanie which is its most important research and development center for automotive engineering outside France. Also, in Bucharest operates Renault Design Central Europe which is the first and only design center of Renault in Romania and South-Eastern Europe. Over 600 companies are active in Romania in the domain of automotive components production, most of which being subsidiaries of international holdings. At the end of this chapter, some priority trends in the development of the automotive industry are presented.
This study aimed to exploit two invasive plant species to develop a novel, multifunctional, bioactive wound dressing based on a microporous cellulosic sponge (CS) from Gleditsia triacanthos pods and functionalizing them with Phytolacca americana fruit extract. The CS was functionalized, lyophilized, and characterized by Attenuated total reflectance–Fourier transform infrared spectroscopy, X-ray diffraction, scanning electron microscopy, contact angle, water absorption, and retention capacity. In addition, two parameters were evaluated in temporal dynamics: controlled release of phenolic compounds and antioxidant activities. The hemolytic index, blood clotting kinetics, lactate dehydrogenase release, and wound scratch assays proved their hemo- and biocompatibility, as well as their ability to promote cell proliferation and migration promoting-activity and to inhibit microbial growth. Furthermore, the obtained spongious material exhibited an anti-inflammatory effect by modulating the macrophages’ secretion profile of IL-6 and IL-10. In conclusion, the microporous cellulosic sponge obtained from G. triacanthos could be used as a vehicle to ensure the controlled release of bioactive principles with pro-wound healing activities extracted from invasive plants. Graphical abstract
The objectives of the study are to analyze the future of direct taxation of the digital economy in the field of corporate income tax. Digitalization has grown steadily, spreading to all areas, especially the economic sector, i.e. the economic activity carried out by taxpayers. In this context of development of the digital economy not only at a national level, but also at the European or global level, there is a need to analyze which state is responsible for taxing the profits obtained through the digital economy. The main research tools were the legal provisions on direct taxation, the literature analyzing and interpreting this field, and the identification of conclusions from the specific practice of taxpayers who have encountered problems, have asked the same questions or perhaps have found the answers necessary for this research. The implications of the study are both theoretical and practical. The topic aims to analyze a modern direct taxation mechanism. On the other hand, companies and countries will be able to determine where the tax has to be paid by the taxpayer.
Chalcones are α,β-unsaturated ketones with great structural diversity and various applications. A chalcone produced by condensation of 2-acetylpyridine with 2-naphthaldehyde (L) was employed for synthesis of two mononuclear complexes: [Eu(L)(hfac)3(H2O)]·0.5CHCl3 and [Tb(L)(hfac)3], where hfac is the hexafluoroacetylacetonate anion. The chalcone and complexes were structurally characterized by single-crystal X-ray diffraction. The chalcone acts as a chelating bidentate ligand. Luminescent properties of the ligand L and the complexes were investigated in the solid state. For these heteroleptic mononuclear complexes, the emission of the Eu(III) and Tb(III) ions was influenced by the excitation wavelength.
Amir et al. (CPM 2017) introduce the approximate string cover problem (ACP) motivated by applications including molecular biology, coding, automata theory, formal language theory and combinatorics. A cover of a string T is a string C for which every letter of T lies within some occurrence of C. The input of the ACP consists of a string T and the goal is to find a string C of length less than the length of T that covers a string \(T'\), which is as close to T as possible (under some predefined distance). Amir et al. study this problem for the Hamming distance and show that it is NP-hard. In this paper we continue the work of Amir et al. and show the following results for the cover length relaxation of the ACP. After observing that the NP-hardness proof by Amir et al. (CPM 2017, TCS 2019) suffers from several lapses, we propose an amendment to the proof. We then introduce an approximation algorithm for a variant of the ACP, in which we aim to maximize the length of the input string minus the distance to the string covered by the approximate cover returned by the algorithm. This problem is naturally as hard as the ACP. We prove an asymptotic approximation ratio of \(\mathcal {O}(\sqrt{|T|})\), where |T| is the size of the input string. Finally, we present an FPT algorithm with respect to the alphabet size and the size of the cover based on a dynamic programming framework.
The model analyzed in this paper has its origins in the description of composites made by a hosting medium containing a periodic array of inclusions coated by a thin layer consisting of sublayers of two different materials. This two-phase coating material is such that the external part has a low diffusivity in the orthogonal direction, while the internal one has high diffusivity along the tangential direction. In a previous paper (Amar in IFB 21:41–59, 2019), by means of a concentration procedure, the internal layer was replaced by an imperfect interface. The present paper is concerned with the concentration of the external coating layer and the homogenization, via the periodic unfolding method, of the resulting model, which is far from being a standard one. Despite the fact that the limit problem looks like a classical Dirichlet problem for an elliptic equation, in the construction of the homogenized matrix and of the source term, a very delicate analysis is required.
This research investigates the evolving nexus between sustainability practices and firm market value, with a specific focus on the rapidly growing Fintech sector. As concerns about environmental, social, and governance (ESG) issues continue to gain prominence, understanding the implications of sustainability efforts on firm performance becomes crucial. This study proposes an empirical exploration of how sustainability initiatives, embedded in ESG scores, undertaken by Fintech firms influence their market valuations. Moreover, the investigation contrasts the findings for the Fintech firms against those for their counterpart Technology firms for the period between 2011 and 2021. The results show that Technology firms are better valued than their Fintech counterparts, which might reflect a perception of higher risk for the later. By employing panel econometric techniques in the system-GMM setting, the paper finds that capital market investors include ESG factors in their valuation of Fintech and Techinology companies, but the environmental and governance-related initiatives at corporate level are most important in this process. The study seeks to contribute to both the theoretical understanding of the sustainability-market value relationship and the practical insights relevant to Fintech firms and their stakeholders.
The initial idealistic perspective associated with the concept of globalization has turned into a bleak evidence in the present, which has taken on the appearance of a disharmonious liberalism in which it is possible to observe a common worldwide increase in economic and social inequalities. The current international economic crises – characterized by a common inflationary growth – have led to a re-evaluation of the principles of the autarkic economy, economically self-sufficient and relatively independent from the external environment: an approach to which economists attribute the term “deglobalization” (Ajami, 2022; Ho, 2022; Paul, 2023). These foregoing points a duty – also in business economics – to review the models proposed over time in search of new hybrid patterns oriented towards a common social vocation, suggested as a dual attention to both internal (facing the aspects regarding the going concern accounting principle) and external (relevant to the economic and social sustainability of its main stakeholders). Therefore, the article assumes as a research question the declination of the new corporate hybrid patterns and the related “competitive advantage” drivers, among which Diversity Management assumes a decisive role in the pursuit of fair and sustainable progress.
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8,698 members
Octavian D. Pavel
  • Department of Organic Chemistry, Biochemistry and Catalysis
Nicolae Cotfas
  • Faculty of Physics
Florentina Hristea
  • Department of Computer Science
Surugiu Camelia
  • Faculty of Administration and Business
90 Panduri Street, 050663, Bucharest, District 5, Romania
Head of institution
Marian Preda
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