TY - JOUR A1 - Maleki, Maniya A1 - Mohammadi, Mahdieh T1 - Velocity and pressure functions of an oscillating flow in a circular Hele-Shaw cell JF - Iranian Journal of Physics Research N2 - In this study, we have investigated the form of velocity and pressure functions of a fluid oscillating between two parallel glass sheets that form a circular Hele-Shaw cell. The flow has been considered to be radial, incompressible and laminar. The time-dependent Navier-Stokes equation has been solved in cylindrical coordinates using Fourier transform, and the oscillating flow velocity across the thickness of the cell has been obtained at different times. The flow velocity function in the unsteady state is related to the vertical component of the coordinates in the form of parabolic functions and also to the inverse of the radial component. The time dependence appears as a simple harmonic with a frequency equal to the oscillation frequency. The velocity of the flow is maximum at the middle of the cell along its height and gradually decreases from the middle towards the top or bottom plane and reaches zero. Pressure does not depend on the height and changes logarithmically with the radius. The dependence of pressure on time is also a simple harmonic with the external frequency, but it has a phase shift with respect to the velocity. Y1 - 2023 U6 - https://doi.org/10.47176/ijpr.22.1.81304 VL - 22 IS - 1 SP - 113 EP - 120 PB - Physics Society of Iran ER - TY - JOUR A1 - Lachowski, Krzysztof A1 - Hammermeister, Florian A1 - Halenz, Bastian A1 - Lieckefett, Florian A1 - Götze, Thomas A1 - Prill, Robert A1 - Becker, Roland T1 - The Patellostabilometer: A New Device for Quantification of Mediolateral Patella Displacement JF - Sensors N2 - Mediolateral patella displacement is of interest for diagnostics and clinically relevant research questions. Apart from manual testing, no standardized method is currently available. Proper quantification of patella mobility is necessary to better understand pathologies at the patellofemoral joint. Patella mobility was assessed in 25 healthy individuals using a Patellostabilometer, a new prototype instrument for quantification of the mediolateral patella displacement. The participants underwent measurements of the mediolateral displacement three times using the Patellostabilome- ter. A maximal force of 10 N was applied for patella movement. Additionally, leg length and circumference of the knee, upper- and lower-leg were measured. Lateral patella displacement of 18.27 ± 3.76 mm (range 15.85–20.64 mm, interquartile range (IQR) of 4.79) was measured. The medial patella displacement showed 24.47 ± 6.59 mm (range 19.29–29.76 mm, IQR of 10.47). The test–retest measurement error was 2.32 ± 1.76 mm (IQR of 2.38 mm), with five outliers. There was greater test–retest variability between the measurements of the medial displacement compared to the lateral one. The test–retest variability reached 7% of the patella displacement. Other parameters provided no significant correlations. Based on the natural patellofemoral mobility, a precise and clinically relevant quantification of patella mobility is allowed. Y1 - 2023 UR - https://www.mdpi.com/1424-8220/23/3/1274 U6 - https://doi.org/https://doi.org/10.3390/s23031274 IS - 23 (3) PB - MDPI ER - TY - JOUR A1 - Rizun, Nina A1 - Revina, Aleksandra A1 - Edelmann, Noella T1 - Application of Text Analytics in Public Service Co-Creation: Literature Review and Research Framework JF - DG.O 2023: The 24th Annual International Conference on Digital Government Research N2 - The public sector faces several challenges, such as a number of external and internal demands for change, citizens' dissatisfaction and frustration with public sector organizations, that need to be addressed. An alternative to the traditional top-down development of public services is co-creation of public services. Co-creation promotes collaboration between stakeholders with the aim to create better public services and achieve public values. At the same time, data analytics has been fuelled by the availability of immense amounts of textual data. Whilst both co-creation and TA have been used in the private sector, we study existing works on the application of Text Analytics (TA) techniques on text data to support public service co-creation. We systematically review 75 of the 979 papers that focus directly or indirectly on the application of TA in the context of public service development. In our review, we analyze the TA techniques, the public service they support, public value outcomes, and the co-creation phase they are used in. Our findings indicate that the TA implementation for co-creation is still in its early stages and thus still limited. Our research framework promotes the concept and stimulates the strengthening of the role of Text Analytics techniques to support public sector organisations and their use of co-creation process. From policy-makers' and public administration managers' standpoints, our findings and the proposed research framework can be used as a guideline in developing a strategy for the designing co-created and user-centred public services. Y1 - 2023 UR - https://dl.acm.org/doi/10.1145/3598469.3598471 U6 - https://doi.org/10.1145/3598469.3598471 SP - 12 EP - 22 PB - Association for Computing Machinery ER - TY - JOUR A1 - Guterding, Daniel T1 - Sparse Modeling Approach to the Arbitrage-Free Interpolation of Plain-Vanilla Option Prices and Implied Volatilities JF - Risks N2 - We present a method for the arbitrage-free interpolation of plain-vanilla option prices and implied volatilities, which is based on a system of integral equations that relates terminal density and option prices. Using a discretization of the terminal density, we write these integral equations as a system of linear equations. We show that the kernel matrix of this system is, in general, ill-conditioned, so that it cannot be solved for the discretized density using a naive approach. Instead, we construct a sparse model for the kernel matrix using singular value decomposition (SVD), which allows us not only to systematically improve the condition number of the kernel matrix, but also determines the computational effort and accuracy of our method. In order to allow for the treatment of realistic inputs that may contain arbitrage, we reformulate the system of linear equations as an optimization problem, in which the SVD-transformed density minimizes the error between the input prices and the arbitrage-free prices generated by our method. To further stabilize the method in the presence of noisy input prices or arbitrage, we apply an 𝐿1-regularization to the SVD-transformed density. Our approach, which is inspired by recent progress in theoretical physics, offers a flexible and efficient framework for the arbitrage-free interpolation of plain-vanilla option prices and implied volatilities, without the need to explicitly specify a stochastic process, expansion basis functions or any other kind of model. We demonstrate the capabilities of our method in a number of artificial and realistic test cases. Y1 - 2023 UR - https://www.mdpi.com/2227-9091/11/5/83 U6 - https://doi.org/https://doi.org/10.3390/risks11050083 IS - 11 (5) PB - MDPI AG ER - TY - JOUR A1 - Stannarius, Ralf A1 - Harth, Kirsten T1 - The structure of disintegrating defect clusters in smectic C freely suspended films JF - Soft Matter N2 - Disclinations or disclination clusters in smectic C freely suspended films with topological charges larger than one are unstable. They disintegrate, preferably in a spatially symmetric fashion, into single defects with individual charges of +1, which is the smallest positive topological charge allowed in polar vector fields. While the opposite process of defect annihilation is well-defined by the initial defect positions, disintegration starts from a singular state and the following scenario including the emerging regular defect patterns must be selected by specific mechanisms. We analyze experimental data and compare them with a simple model where the defect clusters adiabatically pass quasi-equilibrium solutions in one-constant approximation. It is found that the defects arrange in geometrical patterns that correspond very closely to superimposed singular defect solutions, without additional director distortions. The patterns expand by affine transformations where all distances between individual defects scale with the same time-dependent scaling factor proportional to the square-root of time. Y1 - 2023 UR - https://pubs.rsc.org/en/content/articlelanding/2023/sm/d3sm00808h U6 - https://doi.org/https://doi.org/10.1039/d3sm00808h IS - 19 SP - 6109 EP - 6115 PB - Royal Society of Chemistry ER - TY - JOUR A1 - Xu, Han-Xiang A1 - Shimizu, Makoto A1 - Guterding, Daniel A1 - Otsuki, Junya A1 - Jeschke, Harald O. T1 - Pressure evolution of electronic structure and magnetism in the layered van der Waals ferromagnet CrGeTe3 JF - Physical Review B N2 - Layered van der Waals ferromagnets, which preserve their magnetic properties down to exfoliated monolayers, are fueling an abundance of fundamental research and nanoscale device demonstration. CrGeTe3 is a prime example of this class of materials. Its temperature-pressure phase diagram features an insulator-to-metal transition and a significant increase in ferromagnetic Curie-Weiss temperatures upon entering the metallic state. We use density functional theory to understand the magnetic exchange interactions in CrGeTe3 at ambient and elevated pressures. We calculate Heisenberg exchange couplings, which provide the correct ferromagnetic ground state and explain the experimentally observed pressure dependence of magnetism in CrGeTe3. Furthermore, we combine density functional theory with dynamical mean-field theory to investigate the effects of electronic correlations and the nature of the high-pressure metallic state in CrGeTe3. Y1 - 2023 U6 - https://doi.org/https://doi.org/10.1103/PhysRevB.108.125142 IS - Vol. 108 PB - American Physical Society ER - TY - JOUR A1 - Klopp, Christoph A1 - Trittel, Torsten A1 - Harth, Kirsten A1 - Stannarius, Ralf T1 - Coalescence of biphasic droplets embedded in free standing smectic A films JF - Soft Matter N2 - We investigate micrometer-sized flat droplets consisting of an isotropic core surrounded by a nematic rim in freely suspended smectic A liquid-crystal films. In contrast to purely isotropic droplets which are characterized by a sharp edge and no long-range interactions, the nematic fringe introduces a continuous film thickness change resulting in long-range mutual attraction of droplets. The coalescence scenario is divided in two phases. The first one consists in the fusion of the nematic regions. The second phase involves the dissolution of a thin nematic film between the two isotropic cores. The latter has many similarities with the rupture of thin liquid films between droplets coalescing in an immiscible viscous liquid. Coalescence of biphasic droplets in free-standing smectic films is controlled in part by the rupture of a thin nematic membrane separating the isotropic droplet cores. Y1 - 2023 UR - https://pubs.rsc.org/en/content/articlelanding/2024/sm/d3sm01549a U6 - https://doi.org/10.1039/d3sm01549a SN - 1744-683X VL - 20 IS - 5 SP - 1036 EP - 1046 PB - Royal Society of Chemistry ER - TY - JOUR A1 - Nagel, Michael A1 - Schminder, Christian ED - Erich Schmidt Verlag, T1 - Sachbezogenes Verhandeln als Methode im Zielbildungsprozess von innovationsorientierten Public Private Partnerships. JF - Ideen- und Innovationsmanagement Y1 - 2023 U6 - https://doi.org/10.37307/j.2198-3151.2022.02.07 SN - 2198-3151 IS - 2 SP - 72 EP - 77 PB - Erich Schmidt Verlag GmbH & Co ER - TY - JOUR A1 - Johannsen, Andreas T1 - ERP-Einführung - Bewertung einer Standardimplementierungsmethode für SAP Business One JF - ERP Management Y1 - 2023 SN - 1860-6725 SP - 19 EP - 22 PB - GITO Verlag ER - TY - JOUR A1 - Kuznetsov, Arthur A1 - Frorip, Aleksandr A1 - Sünter, Alar A1 - Kasvand, Nensi A1 - Korsakov, Vadim A1 - Konoplev, Georgii A1 - Stepanova, Oksana A1 - Rusalepp, Linda A1 - Anton, Dea A1 - Püssa, Tõnu A1 - Roasto, Mati A1 - Abramova, Liubov A1 - Kozin, Andrey A1 - Toom, Lauri A1 - Hirsch, Sören A1 - Mukhin, Nikolay ED - mdpi, T1 - Fast Protein and Metabolites (Nucleotides and Nucleosides) Liquid Chromatography Technique and Chemical Sensor for the Assessment of Fish and Meat Freshness JF - Chemosensors N2 - Fast protein and metabolite liquid chromatography (FPLMC) was introduced years ago to enable the easy separation of high-molecular compounds such as proteins from small molecules and the identification of the low-molecular substances. In this paper, the method is applied for the rapid evaluation of freshness and monitoring the aging of animal meat and fish. A novel chromatographic sensor was developed with a deep UV LED-based photometric detection unit (255–265 nm), an original flow cuvette and registration scheme; the processing of a chromatogram with the sensor takes approximately 15 min. Strict isochronism between the elution of ATP metabolites, mainly hypoxanthine (Hx) and inosine monophosphate (IMP), and the time of maturation of meat or fish, was discovered. A new freshness index H* = [Hx]/[IMP] was introduced, which is proportional to the instrumental delay time in the FPMLC chromatograms: the H* index < 0.5 indicates the presence of inosine monophosphate (IMP) and the high quality of the meat or fish. Reasonably strong correlations were revealed between data obtained by FPMLC and total volatile basic nitrogen TVB-N (for fish) or volatile fatty acids VFA (for meat) content. Moreover, putative nucleotide salvage and an increase in the concentration of IMP were observed in fish after heat treatment using the FPMLC sensor and NMR technique. Y1 - 2023 UR - https://www.mdpi.com/2227-9040/11/1/69 U6 - https://doi.org/10.3390/chemosensors11010069 SN - 2227-9040 IS - 1/2023 / Band 11 PB - MDPI ER - TY - JOUR A1 - Mikhailov, Ivan Igorevich A1 - Lamkin, I. A. A1 - Degterev, Aleksandr A1 - Degtereva, Mariya A1 - Pavlova, Marina A1 - Kurachkina, Marharyta A1 - Tarasov, S. A. A1 - Kuzmina, Ulyana T1 - Фоточувствительные структуры с каскадными концентраторами излучения на основе коллоидных квантовых точек халькогенидов металлов JF - Journal of the Russian Universities Radioelectronics N2 - The problem of increasing the efficiency of existing photodetectors and creating their new types attracts much research attention. Among new photodetector types are photosensitive structures based on cascade concentrators, whose operational principle involves the absorption of optical radiation followed by its reemission at a longer wavelength and radiation concentration onto a highly efficient small-area photodetector. The absorption and re-emission spectra of each cascade layer depend on the characteristics of the material used. Сolloidal quantum dots are among the most promising materials for cascade layers due to their manufacturing technology, which provides for accurate control over the photoluminescence maximum position. It seems highly relevant to develop and to study photosensitive structures with cascade concentrators of various shapes based on CdS, CdSe/ZnS, and PbS colloidal quantum dots. Aim . To develop photosensitive structures with a wide-range sensitivity spectrum based on concentrators containing arrays of metal chalcogenide CQDs and to study their characteristics. Materials and methods . Cascade photosensitive structures were manufactured based on layers made of polymethyl methacrylate and layers of colloidal quantum dots embedded in a polystyrene matrix. Results . Three-layer concentrators were manufactured with different colloidal quantum dots in each concentrator layers. A 22 % increase in the output power was observed for a three-layer cascade structure based on different cascade layer materials compared to a similar structure using a single layer concentrator. Conclusion . The conducted studies showed an increase in the efficiency of photosensitive structures with a cascade concentrator based on colloidal quantum dots of various types (CdS, CdSe/ZnS, and PbS) in the cascade layers. T2 - Photo-sensitive Structures with Cascade Radiation Concentrators Based on Colloidal Quantum Dots of Metal Chalcogenides Y1 - 2023 U6 - https://doi.org/10.32603/1993-8985-2023-26-2-78-88 SN - 2658-4794 VL - 26 IS - 2 SP - 78 EP - 88 PB - Saint Petersburg Electrotechnical University ER - TY - RPRT A1 - Reimann, Christoph A1 - Shetty, Darshan A1 - Klecha, Dominik A1 - Munaf, Jasmin A1 - Boateng, Newell T1 - Absence of external resources in Germany BT - An analysis about the deglobalization of resources in Germany based on the case studies oil and gas and rare earths N2 - This scientific paper deals with the question of to what extent the deglobalization of raw materials will have an impact on Germany. For this purpose, a general understanding of the terms “globalization” and “deglobalization” will be provided. In addition, the drivers and challenges of (de)globalization are explained in more detail. The question was then examined based on specific case studies, which are decisive for today's prosperity and are predominantly imported. This includes gases, oils, and rare earths. The paper distinguishes between the effects of a loss of these resources on Germany, if the deglobalization takes place slowly and planned or unplanned and fast. The effects are then considered at three different levels: at the government level, at the corporate level, and at the population level. At the corporate level, the focus was primarily on the largest German industries. Each of the case studies ends with possible hypothetical scenarios that do not have to happen but could happen in the worst case. The scenarios show how bad things can get and provide an answer to the scientific question of how deglobalization in the case study could affect Germany. KW - Natürliche Ressourcen KW - Globalisierung KW - Fallstudie Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:522-opus4-28928 ER - TY - JOUR A1 - Baecker, Christoph A1 - Alabbadi, Osama A1 - Yogiputra, Georgius Pradipta A1 - Tien Dung, Nguyen T1 - Threats provided by artificial intelligence that could disrupt the democratic system N2 - This research paper examines the potential consequences of AI technology on democratic systems. The study focuses on two main areas: the weakening of the media and the emergence of "smart dictatorship." The paper examines the ways in which AI can be used to supervise, manipulate, and frustrate the media, thereby weakening its role as a check on government and corporate power. The study also explores how AI technology can be used to create an "omnidirectional monitoring" society, where individuals are constantly monitored and controlled through the use of "panopticon" techniques and "social bots". This can lead to the emergence of a "postdemocratic" society, characterized by growing inequality, dehumanization, and the manipulation of information on online media platforms. The research methodology adopted in the study is qualitative, using expert interviews with three experts who discussed the overall use of AI and its disruptive effects on democracy, such as the creation of fake news, filter bubbles, and algorithm bias. In conclusion, this research highlights the need for increased awareness and regulation of AI technology to ensure its responsible use and to protect democratic values. KW - Künstliche Intelligenz KW - Demokratie KW - Wertordnung Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:522-opus4-28988 PB - Technische Hochschule Brandenburg ER - TY - THES A1 - Garzón Gil, Zahira A1 - Ingabire, Noella Arlette A1 - Kibathi, Patrick T1 - Disruption of Africa's education systems and economic development due to overpopulation N2 - Education lies at the foot of economic growth and human development. However, an increase in population tends to put a strain on existing education systems, especially in Africa where most countries are characterized by slow economic development, rapid population growth rates and a median age just shy of 20 years. Due to the slow rate of economic growth, many African countries lack the financial capability to provide proper education for their ever-growing populations or even already overpopulated regions, many of which have people who have reached the appropriate school-going age. This leads to a series of disruptive impacts on the education systems resulting in a people who are poorly or improperly educated, and thus are not equipped with the necessary skills required for the vast technical, professional and ever modernizing high-skill job markets such as construction, economic and technical professions, teaching occupations and so on, all of which drive economic growth and development. Therefore, we can see that rapid population growth, if left unchecked, may lead to overpopulation scenarios which could have a negative disruptive impact on education and human development, both of which are important factors necessary for economic growth. Key words: Population, education, Africa, poverty, economy, development. KW - Übervölkerung KW - Afrika KW - Armut KW - Demographie Y1 - 2023 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:kobv:522-opus4-28909 EP - 21 Seiten ER - TY - CHAP A1 - Weretecki, Patrick A1 - Kristal, Samuel T1 - Brand Value Co-Creation bei der Deutschen Telekom- Das (neu) entdeckte Potential der regionalen Marketingkommunikation T2 - Marketing-Management : Konzepte - Instrumente - Unternehmensfallstudien / Philip Kotler, Kevin Lane Keller, Alexander Chernev, Marc Oliver Opresnik ; Übersetzung: Anke Harrer, Oberschleißheim - 16. aktualisierte Aufl. - München: Pearson, 2023 Y1 - 2024 SN - 978-3-86894-443-3 SP - 363 EP - 368 PB - Pearson ER - TY - CHAP A1 - Markgraf, Klaus T1 - Entwicklung eines Tools zur spezifischen, lastgangbasierten Eigenverbrauchsoptimierung mittels PV-Leistungsprognose T2 - Konferenz: 18. Symposium Energieinnovation, 2024, Graz/Austria N2 - The German government's initiative to cover 80% of the gross electricity supply with renewable energies by 2050 brings considerable ecological benefits, but also poses several challenges. One of these challenges is the growing number of photovoltaic systems (PV systems), which, due to their high feed-in power, already pose a risk to the security of the electricity distribution grid during long periods of sunny weather. To counteract this, active research is being carried out in the field of PV power forecasting. This research is primarily aimed at providing the grid operator with a predicted power output, which enables a longer planning horizon and thus increases the operational grid security. However, the considerable annual electricity consumption of private households and the increasing spread of PV systems for self-consumption show that the energy behavior of households, especially self-consumption, also influences grid security. Additionally, households have an incentive to boost their self-consumption because the cost of drawing each kilowatt-hour from the grid is substantially higher than the compensation received for injecting an equivalent amount of energy back into the grid. However, as of now, there is no software available that easily enables households to tailor the usage patterns of their electrical appliances according to a photovoltaic (PV) forecast. The project described here aims to close this gap by creating such software. Various PV forecasting models are used and tested for their suitability for this purpose. A self-generated optimization process is implemented in this project to optimize the consumer configuration based on the PV forecasts. The here-developed tool enables the user to enter parameters for his PV system and the specific load profiles of his electrical appliances. Based on this data, the optimization algorithm determines a consumption plan with a forecast horizon until the end of the next day that maximizes the user's self-consumption. To validate the tool, the optimization process is carried out over a period of 60 days using a predefined scenario and the results are compared with a scenario in which the electrical appliances are intuitively operated at midday. The analysis of these results ultimately shows the potential impact of such a tool on the economic efficiency of private households and the supply stability. Y1 - 2024 U6 - https://doi.org/10.6084/m9.figshare.25610976 SP - 1 EP - 10 ER - TY - JOUR A1 - Ayalon, Inbal A1 - Avisar, Dror A1 - Jechow, Andreas A1 - Levy, Oren T1 - Corals nitrogen and carbon isotopic signatures alters under Artificial Light at Night (ALAN) JF - The Science of The Total Environment N2 - This study examines the impact of Artificial Light at Night (ALAN) on two coral species, Acropora eurystoma and Pocillopora damicornis, in the Gulf of Aqaba/Eilat Red Sea, assessing their natural isotopic responses to highlight changes in energy and nutrient sourcing due to sensory light pollution. Our findings indicate significant disturbances in photosynthetic processes in Acropora eurystoma, as evidenced by shifts in δ13C values under ALAN, pointing to alterations in carbon distribution or utilization. In Pocillopora damicornis, similar trends were observed, with changes in δ13C and δ15N values suggesting a disruption in its nitrogen cycle and feeding strategies. The study also uncovers species-specific variations in heterotrophic feeding, a crucial factor in coral resilience under environmental stress, contributing to the corals' fixed carbon budget. Light measurements across the Gulf demonstrated a gradient of light pollution which possess the potential of affecting marine biology in the region. ALAN was found to disrupt natural diurnal tentacle behaviors in both coral species, crucial for prey capture and nutrient acquisition, thereby impacting their isotopic composition and health. Echoing previous research, our study underscores the need to consider each species' ecological and physiological contexts when assessing the impacts of anthropogenic changes. The findings offer important insights into the complexities of marine ecosystems under environmental stress and highlight the urgency of developing effective mitigation strategies. Y1 - 2024 U6 - https://doi.org/10.1016/j.scitotenv.2024.170513 IS - 920 PB - Elsevier ER - TY - JOUR A1 - Trittel, Torsten A1 - Puzyrev, Dmitry A1 - Stannarius, Ralf T1 - Platonic solids bouncing on a vibrating plate JF - Physical Review E N2 - The energy transfer between bouncing particles and rigid boundaries during impacts is crucially influenced not only by restitution coefficients of the material but also by particle shapes. This is particularly important when such particles are mechanically agitated with vibrating plates. Inertial measurement units are able to measure all acceleration and rotational velocity components of an object and store these data for subsequent analysis. We employ them to measure the dynamics of cubes and icosahedra on vibrating plates to study the efficiency of energy transfer into the individual degrees of freedom (DOFs) of the excited object. The rotational DOFs turn out to be much less excited than the vertical translational motion. Most remarkably, there is only little difference between the two Platonic solids in both the absolute energies and the energy partition ratios. Y1 - 2024 U6 - https://doi.org/10.1103/PhysRevE.109.034903 VL - 109 IS - 3 PB - American Physical Society ER - TY - JOUR A1 - Kristal, Samuel A1 - Weretecki, Patrick T1 - Social first? Not always! Brand co-creation through regional marketing at Deutsche Telekom JF - Transfer: Zeitschrift für Kommunikation & Markenmanagement N2 - Deutsche Telekom, one of the world's leading integrated telecommunications companies, has recently shifted its focus in event marketing to prioritize more personal co-creational communication on regional occasions, rather than largescale events. This paper outlines the three-part LAW-principle that Deutsche Telekom follows in its brand communication in Germany, providing examples for each of the three pillars. The co-creation resulting from brand communication is changing the role of marketing and brand practitioners. They are now required to negotiate with various stakeholders. Y1 - 2024 VL - 70 IS - 1 SP - 67 EP - 71 PB - New Business Verlag ER - TY - JOUR A1 - Catalano, Francesco A1 - Nasello, Laura A1 - Guterding, Daniel T1 - Quantum Computing Approach to Realistic ESG-Friendly Stock Portfolios JF - Risks N2 - Finding an optimal balance between risk and returns in investment portfolios is a central challenge in quantitative finance, often addressed through Markowitz portfolio theory (MPT). While traditional portfolio optimization is carried out in a continuous fashion, as if stocks could be bought in fractional increments, practical implementations often resort to approximations, as fractional stocks are typically not tradeable. While these approximations are effective for large investment budgets, they deteriorate as budgets decrease. To alleviate this issue, a discrete Markowitz portfolio theory (DMPT) with finite budgets and integer stock weights can be formulated, but results in a non-polynomial (NP)-hard problem. Recent progress in quantum processing units (QPUs), including quantum annealers, makes solving DMPT problems feasible. Our study explores portfolio optimization on quantum annealers, establishing a mapping between continuous and discrete Markowitz portfolio theories. We find that correctly normalized discrete portfolios converge to continuous solutions as budgets increase. Our DMPT implementation provides efficient frontier solutions, outperforming traditional rounding methods, even for moderate budgets. Responding to the demand for environmentally and socially responsible investments, we enhance our discrete portfolio optimization with ESG (environmental, social, governance) ratings for EURO STOXX 50 index stocks. We introduce a utility function incorporating ESG ratings to balance risk, return and ESG friendliness, and discuss implications for ESG-aware investors. Y1 - 2024 UR - http://dx.doi.org/10.3390/risks12040066 U6 - https://doi.org/10.3390/risks12040066 SN - 2227-9091 VL - 12 IS - 4 SP - 1 EP - 12 PB - MDPI ER -