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Found 6407 publications

The coupled cluster method and entanglement in three fermion systems

Gábor Sárosi János Pipek Péter Lévay Szilvia Nagy

Publication Name: Journal of Mathematical Physics

Publication Date: 2017-01-01

Volume: 58

Issue: 1

Page Range: Unknown

Description:

The Coupled Cluster (CC) and full CI expansions are studied for three fermions with six and seven modes. Surprisingly the CC expansion is tailor made to characterize the usual stochastic local operations and classical communication (SLOCC) entanglement classes. It means that the notion of a SLOCC transformation shows up quite naturally as a one relating the CC and CI expansions, and going from the CI expansion to the CC one is equivalent to obtaining a form for the state where the structure of the entanglement classes is transparent. In this picture, entanglement is characterized by the parameters of the cluster operators describing transitions from occupied states to singles, doubles, and triples of non-occupied ones. Using the CC parametrization of states in the seven-mode case, we give a simple formula for the unique SLOCC invariant I. Then we consider a perturbation problem featuring a state from the unique SLOCC class characterized by I. For this state with entanglement generated by doubles, we investigate the phenomenon of changing the entanglement type due to the perturbing effect of triples. We show that there are states with real amplitudes such that their entanglement encoded into configurations of clusters of doubles is protected from errors generated by triples. Finally we put forward a proposal to use the parameters of the cluster operator describing transitions to doubles for entanglement characterization. Compared to the usual SLOCC classes, this provides a coarse grained approach to fermionic entanglement.

Open Access: Yes

DOI: 10.1063/1.4974510

Automated multi-stream spiral-wound heat exchanger design and optimization

Chenglin Chang Zekun Yang Shuhao Zhang Ting Pan Nan Zhang Robin Smith

Publication Name: Applied Thermal Engineering

Publication Date: 2026-01-30

Volume: 284

Issue: Unknown

Page Range: Unknown

Description:

Spiral-wound heat exchangers (SWHEs) offer high heat transfer efficiency and compact design advantages, making them well-suited for services in process industries. Accelerating the application of SWHEs demands design methodologies that avoid extensive user manipulations and complex solution procedures. This study develops a novel incremental-based heat transfer framework for the automated design of single-phase SWHEs, which simultaneously optimizes multi-stream allocation across activated tube layers and exchanger geometries. At each increment, energy balances are enforced for all streams using local heat transfer coefficients and areas. On the tube-side, flow distribution is optimized by permitting variable split heat capacities and mass flow rates within tube layers while ensuring pressure balance for each stream at the bundle outlet. New correlations for shell-side flow regimes are introduced into the proposed sizing model to link discrete tube-layer selections with their corresponding cross-sectional areas throughout the optimization process. The capability of the proposed framework is demonstrated through four case studies, including model validation, two-stream and multi-stream SWHE design, and application to an industrial-scale heat exchanger network (HEN). Rigorous Aspen EDR-CoilWound simulations validate the proposed model and design results, with the HEN case exhibiting only a 2.95 % deviation from the target duty. In Case Study 2, SWHE results in a 24.29 % reduction in required heat transfer area. Case Studies 3 and 4 demonstrate that SWHE configurations can achieve 31.8 %–40.7 % reductions in exchanger volume, attributable to their superior compactness relative to conventional shell-and-tube heat exchangers (STHEs). Benchmarking against detailed STHE designs further clarifies optimal deployment strategies and highlights residual limitations of SWHE technology.

Open Access: Yes

DOI: 10.1016/j.applthermaleng.2025.128914

Nonlinearity in the finite element simulations

Miklós Kuczmann

Publication Name: Przeglad Elektrotechniczny

Publication Date: 2010-12-20

Volume: 86

Issue: 12

Page Range: 83-86

Description:

The paper presents the four possible nonlinear schemes to solve nonlinear static magnetic field problems and eddy current field problems by the fixed point technique while using the polarization formulation to linearize the nonlinear curve of the constitutive law of ferromagnetic materials. The finite element method (FEM) has been chosen as a numerical tool to present the applicability of the technique.

Open Access: Yes

DOI: DOI not available

Modeling of railway transition zones under dynamic loading

Edina Koch Peter Hudacsek

Publication Name: Icsmge 2017 19th International Conference on Soil Mechanics and Geotechnical Engineering

Publication Date: 2017-01-01

Volume: 2017-September

Issue: Unknown

Page Range: 1369-1372

Description:

Transition zones of railway tracks are intended to provide a smooth transition of the riding train, minimizing the effect of the discontinuities that exist along the track. When a train rides from an embankment onto a stiff structure, such as a bridge, tunnel or culvert, an abrupt change in the support stiffness occurs possibly inducing differential settlements. This in long term can yield to the degradation of the tracks and foundations in the transition zones. The differential settlement is especially problematic for high speed rail infrastructure as the "bump" at the transition is accentuated at high speeds. A number of techniques have been proposed or implemented to provide gradual stiffness transition at the problem zones, such as methods to ensure gradually changing pad stiffness, application of long sleepers or installation of auxiliary rails in the transition zone. The problems associated with the transition zones require a complex analysis. For efficient modeling of the mechanisms resulting in gradual line deteriorations in the transition zones the understanding of the 3D and dynamic effects associated with the problem seems to be essential. To enhance our understanding regarding the problem a 3D numerical model has been developed and presented for time domain analysis.

Open Access: Yes

DOI: DOI not available

Damping determination by the half power bandwidth method for a rectangular flat plate with bitumen damping layer application

Dániel Feszty Balázs Vehovszky Marcell Treszkai

Publication Name: Journal of Vibroengineering

Publication Date: 2021-08-01

Volume: 23

Issue: 5

Page Range: 1267-1277

Description:

Damping Loss Factor (DLF) is an important input parameter in Statistical Energy Analysis (SEA) simulations, therefore its accurate determination via measurement is crucial from simulation accuracy point of view. This paper presents a methodology for the accurate measurement of DLF via the Half Power Bandwidth Method (HPBM) for three test cases: A) a rectangular steel plate, b) the same plate with viscoelastic bitumen sheets imposed on the middle of plate and c) the same plate with the viscoelastic bitumen sheets placed randomly. The aim of the different bitumen layer applications was to develop a methodology for representing them in Statistical Energy Analysis, since this simulation technique takes into account only the coverage of the damping layers but not their distribution over a panel. Measurement of the DLF in random locations on the plate gave the appropriate parameters for the simulation. Measurement results were then applied in SEA simulations, which showed good agreement with the experimental results in all test cases, with the maximum difference of only 2 dB.

Open Access: Yes

DOI: 10.21595/jve.2021.21938

Adoptive T-cell therapies for persistent COVID-19 in immunocompromised patients: Comparison of IFN-γ virus-specific T-cell therapy and CD45RA+ T-cell depleted donor lymphocyte infusion

Dóra Mathiász Nóra Meggyesi János Sinkó Gabriella Bekő Botond Lakatos Andrea Ceglédi Hajnalka Andrikovics István Vályi-Nagy Bálint Gergely Szabó Szabolcs Tasnády Borisz Rabán Petrik Judit Bogyó Katalin Dobos Laura Giba-Kiss Orsolya Kis Gottfried Miskolczi Noémi Németh Ilona Bobek László Gopcsa János Szlávik Péter Reményi Marienn Réti Zsuzsanna Várnai Anikó Szilvási

Publication Name: Geroscience

Publication Date: 2026-01-01

Volume: Unknown

Issue: Unknown

Page Range: Unknown

Description:

Advanced age, comorbidities, and immunocompromised states remain major risk factors for severe or persistent COVID-19 despite vaccination and antivirals, underscoring the need for innovative treatments such as adoptive T-cell therapy (ATT). In this prospective single-center study, we evaluated the safety, feasibility, and efficacy of two ATT approaches in immunocompromised patients with high-risk or persistent SARS-CoV-2 infection: interferon-γ cytokine capture system virus-specific T cells (IFN-γ CCS VST, n = 12; median age 59) and CD45RA + T-cell depleted donor lymphocyte infusion (CD45RA+ TCD DLI, n = 11; median age 46). Most patients (73.9%) had undergone prior hematopoietic stem cell transplantation (HSCT). Both treatments were safe, with no adverse events observed. One-year overall survival (OS) did not differ significantly between groups (p = 0.8907 overall; p = 0.5907 in HSCT recipients). However, CD45RA+ TCD DLI showed a trend toward improved 1-year COVID-19–free survival (p = 0.058) and significantly better survival among HSCT recipients (p = 0.0362). Viral clearance was achieved in most patients (90.9% vs. 83.3%). Immunomonitoring revealed distinct immune dynamics: between weeks 5–8, IFN-γ CCS VST promoted naïve T-cell expansion with broad cytokine elevation, while CD45RA+ TCD DLI expanded memory T cells with a more restricted cytokine profile. IFN-γ CCS VST also elicited stronger in vivo expansion of SARS-CoV-2–specific CD4 + and CD8 + T cells. In summary, both ATT approaches are safe and effective in immunocompromised patients with persistent COVID-19. CD45RA+ TCD DLI, which can be generated from convalescent donors as an off-the-shelf product, may provide a practical strategy for pandemic preparedness and treatment of vulnerable patients with immune senescence.

Open Access: Yes

DOI: 10.1007/s11357-025-02050-5

Travel Demand Increment Due to the Use of Autonomous Vehicles

Balázs Horváth Dilshad Mohammed

Publication Name: Sustainability Switzerland

Publication Date: 2023-06-01

Volume: 15

Issue: 11

Page Range: Unknown

Description:

Advanced technology available in promising fully autonomous vehicles (AVs) will encourage people to travel more than they have up to now using their regular vehicles. It is believed that the disadvantages of manually driven vehicles, such as driving fatigue, stressful feelings, aging physical skills deterioration, and other unwanted effects, will vanish once AVs are employed. For this purpose, this study presents the results of a large questionnaire performed in Győr, Hungary, about the public perception and acceptance of AVs. In addition, assessing the impact of using such technology on increasing travel demand when people can alter their mode of transport to an AV. The study demonstrates that respondents’ prior knowledge of AVs plays a crucial role in generating a greater number of trips when they are able to use AVs. Furthermore, it has also been found that providing further awareness and education to the population about the meaning of the term autonomous vehicles and widening their insights about the new features provided by these vehicles will result in a higher number of trips. Eventually, this information will act as a considerable indicator to provide a prior understanding of the possible challenges that may impact the sustainability of future transport systems.

Open Access: Yes

DOI: 10.3390/su15118937

Anchoring Bias in Generative AI: A Comparative Analysis of Large Language Models in a Pricing Scenario

Boglárka Eisingerné Balassa Réka Koteczki

Publication Name: 2025 IEEE 16th International Conference on Cognitive Infocommunications Coginfocom 2025

Publication Date: 2025-01-01

Volume: Unknown

Issue: Unknown

Page Range: 115-120

Description:

Generative artificial intelligence systems are increasingly appearing in decision-support processes, so it is essential to address the extent to which these models are prone to human-like cognitive biases. This study investigates whether anchoring bias can be detected in large language models in a simulated market decision-making situation where the AI's task was to determine the launch price of a new smartwatch. In the experimental setup, five different generative AI models (GPT-4o, GPT-4.5, Gemini 2.5 Pro, Grok 3 Beta, Sonar) were tested with low and high numerical anchor values. For each model, 20 runs were performed under both conditions (a total of 200 queries), and the results were analyzed using an independent sample t-test and an anchoring index. Based on the results, the GPT-4o model showed significant anchoring bias (AnI=13.12%), while in the case of GPT-4.5, this was more moderate (AnI =5.67%). The responses of the other models were completely consistent, with a standard deviation of 0 and no changes observed between different anchoring conditions. The hypothesis tests confirmed that the anchoring effect is not universally characteristic, but rather a model-dependent behavioral peculiarity. The study contributes to the measurement of bias sensitivity in artificial intelligence and to the development of a possible future behavioral benchmark. The practical significance of the research is that it draws attention to the fact that individual models may be sensitive to irrelevant numerical contexts, which can lead to biased results in business decisions. Therefore, for companies, not only language performance but also this type of bias profile may be an important consideration when selecting and deploying generative AI systems.

Open Access: Yes

DOI: 10.1109/CogInfoCom66819.2025.11200816

A discrete bacterial memetic evolutionary algorithm for the traveling salesman problem

Péter Földesi Boldizsár Tüu-Szabó Laszlo T. Koczy

Publication Name: 2016 IEEE Congress on Evolutionary Computation CEC 2016

Publication Date: 2016-11-14

Volume: Unknown

Issue: Unknown

Page Range: 3261-3267

Description:

This paper presents a Discrete Bacterial Memetic Evolutionary Algorithm (DBMEA) for the Traveling Salesman Problem. This algorithm combines the very efficient bacterial evolutionary algorithm with 2-opt and 3-opt local searches. Our approach was tested on TSPLIB and other VLSI benchmark problems. In this paper our computational results (minimal tour lengths, run times) are compared with other efficient TSP solver algorithms (Lin-Kernighan, Concorde). We will show that in significant number of the published benchmark problems the optimal tour was not found by the Concorde algorithm and the Lin-Kernighan heuristic because this approaches use an approximation substituting distances of points by the closest integer values. We suggest the substitution of the benchmark result set by the real optima calculated by the new DBMEA algorithm and the use of DBMEA heuristic as more precise for the solution of TSP and other NP-hard optimization problems.

Open Access: Yes

DOI: 10.1109/CEC.2016.7744202