Transition Scheme Research Articles

EURAD state-of-the-art report: development and improvement of numerical methods and tools for modeling coupled processes in the field of nuclear waste disposal

The Strategic Research Agenda (SRA; https://www.ejp-eurad.eu/publications/eurad-sra) of the European Joint Programme on Radioactive Waste Management (EURAD; https://www.ejp-eurad.eu/) describes the scientific and technical domains and sub-domains and knowledge management needs of common interest between EURAD participant organizations. Theme number 7 is entitled “Performance assessment, safety case development and safety analyses.” A list of research and development priorities and activities of common interest to be addressed within EURAD for theme 7 have been established. Amongst others, the Understanding and modelling of multi-physical Thermo-Hydro-Mechanical-Chemical coupled processes (THMC) occurring in radioactive waste disposal is a major and permanent issue to support optimization of design and safety case abstraction. To tackle this challenge a research work package entitled “DONUT: Development and improvement of numerical methods and tools for modelling coupled processes” has been conducted within the EURAD join programming initiative. The purpose of this work package is to improve/develop methods or numerical tools in order to go a step further in development of (i) relevant, performant and cutting-edge numerical methods that can easily be implemented in existing or new tools, in order to carry out high-performance computing to facilitate the study of highly coupled processes in large systems, (ii) numerical scale transition schemes for coupled processes, (iii) innovative numerical methods to carry out uncertainty and sensitivity analyses. In this paper the work carried out within the DONUT work package is put in perspective regarding the existing concept and literature on the field. It does not pretend to be exhaustive but rather to put emphasis on particular issues tackled during the project.

Attribute-Based Designated Combiner Transitive Signature Scheme

Transitive signatures allow any entity to obtain a valid signature of (i,k) by combining signatures of (i,j) and (j,k). However, the traditional transitive signature scheme does not offer fine-grained control over the combiner. To address this issue, we propose a formal definition of the attribute-based designated combiner transitive signature (ABDCTS) and its security model, where only entities whose inherent attributes meet the access policy can combine signatures. By introducing the fine-grained access control structure, control over the combiner is achieved. To demonstrate the feasibility of our primitive, this paper presents the first attribute-based designated combiner transitive signature scheme. Under an adaptive chosen-message attack, we prove its security based on the one-more CDH problem and the co-CDH problem, and that its algorithms have robustness.

Mathematical principles of mechanical movements

The article proves that kinematic and dynamic theories in classical mechanics by I. Newton, considered a mathematical model of body displacement, are based on the laws of arithmetic progression (or linear function), trigonometry and quadratic function (equation). It is shown that formulas, equations of motion and graphs of dependencies in these theories are mathematical mechanisms that implement the relationship between uniformly varying mechanical quantities and quantities that implement (modify) changes. It is shown that the transition of a uniform change of one value to an accelerated (progressive) change occurs according to the scheme of transition of a linear function into a quadratic equation. It is shown that the formula of an arithmetic progression (linear function) is created by moving from variables in a quadratic equation to a time variable, and from changing and changing parameters to the coordinate, velocity and acceleration of the progression. In order for the content of the article to correspond to the topic, priority was given to mathematical initiatives (prerequisites, originals) of all the problems under consideration.

Caregivers' burden of care during emergency department care transitions among older adults: a mixed methods cohort study.

Improving care transitions for older adults can reduce emergency department (ED) revisits, and the strain placed upon caregivers. We analyzed whether caregivers felt a change in burden following a care transition, and what may be improved to reduce it. This mixed-methods observational study nested within LEARNING WISDOM included caregivers of older patients who experienced an ED care transition. Burden was collected with the brief Zarit Burden Interview (ZBI-12), and caregivers also commented on the care transition. A qualitative coding scheme of patient care transitions was created to reflect themes important to caregivers. Comments were randomly analyzed until saturation and themes were extracted from the data. We followed both the SRQR and STROBE checklists. Comments from 581 caregivers (mean age (SD) 64.5 (12.3), 68% women) caring for patients (mean age (SD) 77.2 (7.54), 48% women) were analyzed. Caregivers overwhelmingly reported dissatisfaction and unmet service expectations, particularly with home care and domestic help. Communication and follow-up from the ED emerged as an area for improvement. Caregivers who reported an increased level of burden following a patient's care transition had significantly higher ZBI scores than caregivers who self-reported stable burden levels. Caregivers with increasing, stable, and improved levels of subjective burden all reported areas for improvement in the care transition process. Themes centering on the capacity to live at home and inadequate communication were most frequently mentioned and may represent serious challenges to caregivers. Addressing these challenges could improve both caregiver burden and ED care transitions.

Calculation of the Activation Energy of Electrical ε2‐Conductivity of Weakly Compensated Semiconductors

A model of tunneling (jumping) migration of charge carriers near their mobility edge in the upper band of neutral states of majority hydrogen‐like impurities is proposed to calculate the energy of thermal activation of electrical ‐conductivity of weakly compensated semiconductors. The difference from the known Hubbard model consists in the scheme of interimpurity transitions of charge carriers and in the method of calculating the position of their tunnel mobility edge. The drift mobility edge of free charge carriers corresponds to the thermal ionization energy of majority impurities , which is located near the c‐band bottom or the v‐band top in n‐ and p‐type semiconductors, respectively, and is due to the overlap of excited states of electrically neutral majority impurities. The position of the tunnel mobility edge for ‐conductivity is determined by taking into account the Coulomb interaction of the majority impurities in the charge states and . It is assumed that doping and compensating impurities form a single simple nonstoichiometric cubic lattice in a crystal matrix. The calculations of the activation energy on the insulator side of the insulator–metal concentration phase transition for weakly compensated p‐Si:B, n‐Si:P, and n‐Ge:Sb crystals quantitatively agree with known experimental data.

A diffusive‐discrete crack transition scheme for ductile fracture at finite strain

SummaryThis study presents a diffusive‐discrete crack transition scheme for stably conducting ductile fracture simulations within a finite strain framework. In the developed scheme, the crack initiation and propagation processes are determined according to an energy minimization problem based on crack phase‐field theory, and the predicted diffusive path is transformed to a discrete representation using the finite cover method during the staggered iterative scheme. In particular, for stably conducting ductile fracture simulations, three computational techniques, the staggered iterative configuration update technique, the subincremental damage update technique, and the crack opening stabilization technique, are introduced. The first and second techniques can be used regardless of whether discrete cracks are considered, and the third technique is specialized for diffusive‐discrete crack transition schemes. Accordingly, ductile fracture simulations with the developed scheme rarely encounter troublesome problems such as oscillations in the displacement field and severe distortion of finite elements that can lead to divergence of calculations. After the crack phase‐field model for ductile fractures is formulated and discretized, the numerical algorithms for realizing the diffusive‐discrete crack transition while maintaining computational stability are explained. Several representative numerical examples are presented to demonstrate the performance and capabilities of the developed approach.

Sustainability certification for renewable hydrogen: An international survey of energy professionals

Hydrogen produced from renewable energy is being promoted to decarbonise global energy systems. To support this energy transition, standards, certification, and labelling schemes (SCLs) aim to differentiate hydrogen products based on their system-wide carbon emissions and method of production characteristics. However, being certified as low-carbon, clean, or green hydrogen does not guarantee broader sustainability across economic, environmental, social, or governance dimensions. Through an international survey of energy-sector and sustainability professionals (n = 179), we investigated the desirable sustainability features for renewable hydrogen SCLs and the perceived advantages and disadvantages of sustainability certification. Our mixed-method study revealed general accordance on the feasible inclusion of diverse sustainability criteria in SCLs, albeit with varying degrees of perceived essentiality. Within the confines of the data, some differences in viewpoints emerged based on respondents’ geographical and supply chain locations, which were associated with the sharing of costs and benefits. Qualitatively, respondents found the idea of SCL harmonisation attractive but weighed this against the risks of duplication, complicated administrative procedures, and contradictory regulation. The implications of this research centre on the need for further studies to inform policy recommendations for an overarching SCL sustainability framework that embodies the principles of harmonisation in the context of multistakeholder governance.

Smart Mobility and Sensor Based-BRT Crusade, the Challenge for Auto Mechanics and Technicians in Africa

African countries with no globally recognized auto manufacturing factories are flooded with the most modern automobiles as soon as they are commercialized in the absence of commensurate skilled local auto mechanics across the continent. In the wake of the Bus Rapid Transit (BRT) scheme in Abuja Nigeria, the first set of luxurious buses purchased ended up as junks within a short period of operation largely due to lack of technician competency. The continuous patronage of a few multinational workshop garages like Toyota, Honda, Kia Motors, etc is hindering the transport agencies from breaking even. This paper is therefore aimed at evaluating the state of bus auto-mechanics and technicians in Nigeria for sustainable hybrid buses for effective BRT in the country. Google search engine was used to source secondary data from dedicated transport and energy-related sites like National Research Council (NRC) Agora Verkehrswende and GIZ, Smart city study, USDoT, and Africa Transport Solution, for the current paradigm shift in automobile energy management. Participatory surveys were carried out in two major motor mechanic villages that house over two hundred (200) workshops. The study reveals that there is a yawning gap between the societal ideal auto-mechanic expectations and the operational woe realities. This work becomes very relevant in view of global urbanization and the crusade for Hybrid Bus Rapid Transit (HBRT) in urban mobility as a panacea to COP28 carbon emission reduction. It is recommended that policymakers in urban transportation at all levels should ensure the certification and re-training of the motor mechanics to be able to maintain those imported modern buses while investing in ITS-based road infrastructure for sustainable BRT in their country

Research on the risk assessment of the power grid enterprises’ agency power purchase business in China: A hybrid multi-attribute decision-making framework based on FUCOM-F and GRA-MARCOS

To steadily promote the reform of sales electricity prices, China has innovatively proposed to carry out grid enterprises’ agency power purchase business (GEAPPB) as a transitional scheme for industrial and commercial users to enter the power market in the future. However, because the GEAPPB covers a wide range of users and involves complex business processes, the risks throughout the process of the GEAPPB will affect the organization and operation of the business. This paper proposes a GEAPPB risk assessment technique. First, a risk evaluation index system containing 10 indicators is designed based on the characteristics and development process of GEAPPB. Second, a risk assessment model based on the fuzzy full consistency method (FUCOM-F) and gray relational analysis (GRA)-improved MARCOS is constructed. Finally, seven grid enterprises in China are taken as examples to verify the validity and scientificity of the model. The results show that improving the accuracy of power forecasting, optimizing the agency power purchase strategy, and strengthening demand response management are the key schemes to reduce the risk of GEAPPB. Compared with the other three evaluation models, the proposed model has good applicability and effectiveness for the risk evaluation of GEAPPB.

Development of transition schemes and optimization measures between normal slab track and ladder-type sleeper track

Severe vibrations and deterioration of track system are often observed due to the sudden change in support stiffness between normal slab track (NST) and damping track. To improve the dynamic performance of both the train and track system when a train runs on the transition zone between the NST and the damping track, we focused on the ladder-type sleeper track (LS track) and developed several optimized transition schemes. Firstly, a train-LS track coupled dynamics mode is developed, and it was verified using field testing. Afterward, using the dynamic responses of train and track systems in the transition zone between the NST and the resilient-fastener slab track (RFS track) as a reference, the shortcomings of the traditional transition scheme are identified, and the optimal transition scheme is developed by comparison of the proposed multiple schemes. Finally, the device for suppressing track vibration (DSTV) is installed on the longitudinal sleeper to alleviate the vibration of the LS track and improve the overall stability of the vehicle and track system during the transition zone. The results indicate that the optimal transition scheme proposed in this study lead to significant improvements in the dynamic performance of both the vehicle and LS track.

Aero-ZnS prepared by physical vapor transport on three-dimensional networks of sacrificial ZnO microtetrapods.

Aeromaterials represent a class of increasingly attractive materials for various applications. Among them, aero-ZnS has been produced by hydride vapor phase epitaxy on sacrificial ZnO templates consisting of networks of microtetrapods and has been proposed for microfluidic applications. In this paper, a cost-effective technological approach is proposed for the fabrication of aero-ZnS by using physical vapor transport with Sn2S3 crystals and networks of ZnO microtetrapods as precursors. The morphology of the produced material is investigated by scanning electron microscopy (SEM), while its crystalline and optical qualities are assessed by X-ray diffraction (XRD) analysis and photoluminescence (PL) spectroscopy, respectively. We demonstrate possibilities for controlling the composition and the crystallographic phase content of the prepared aerogels by the duration of the technological procedure. A scheme of deep energy levels and electronic transitions in the ZnS skeleton of the aeromaterial was deduced from the PL analysis, suggesting that the produced aerogel is a potential candidate for photocatalytic and sensor applications.

BARET: Balanced Attention Based Real Image Editing Driven by Target-Text Inversion

Image editing approaches with diffusion models have been rapidly developed, yet their applicability are subject to requirements such as specific editing types (e.g., foreground or background object editing, style transfer), multiple conditions (e.g., mask, sketch, caption), and time consuming fine-tuning of diffusion models. For alleviating these limitations and realizing efficient real image editing, we propose a novel editing technique that only requires an input image and target text for various editing types including non-rigid edits without fine-tuning diffusion model. Our method contains three novelties: (I) Target-text Inversion Schedule (TTIS) is designed to fine-tune the input target text embedding to achieve fast image reconstruction without image caption and acceleration of convergence. (II) Progressive Transition Scheme applies progressive linear interpolation between target text embedding and its fine-tuned version to generate transition embedding for maintaining non-rigid editing capability. (III) Balanced Attention Module (BAM) balances the tradeoff between textual description and image semantics. By the means of combining self-attention map from reconstruction process and cross-attention map from transition process, the guidance of target text embeddings in diffusion process is optimized. In order to demonstrate editing capability, effectiveness and efficiency of the proposed BARET, we have conducted extensive qualitative and quantitative experiments. Moreover, results derived from user study and ablation study further prove the superiority over other methods.

Effectiveness and efficiency of support schemes in promoting renewable energy sources in the Spanish electricity market

This research paper delves into the central mechanisms implemented in Spain to foster the adoption of clean energy projects. The study scrutinizes various mechanisms established from 2005 onwards, evaluating their efficacy in achieving the desired outcome of supporting clean energy project implementation. The aim is to comprehensively assess the associated costs, effectiveness, and attainment of renewable energy objectives stemming from implementing diverse support schemes. This paper explores the effectiveness of feed-in tariffs and feed-in premium mechanisms in promoting the integration of new renewable energy generation into the power system. However, the Spanish experience suggests that exhaustive planning control is imperative to prevent excessive support costs that could jeopardize the entire market and cause a significant rise in final energy costs. The research studies the support schemes and associated market distortion and presents the roadmap from regulated tariffs to a “total market” for wind and solar energy. The findings demonstrate that, under proper supervision and planning, a transitional retribution scheme effectively promotes renewable energy plant integration. Finally, the analysis examines the need to regulate the excess benefits that non-emitting power sources receive in a marginal price market, as this can lead to market imbalances and a substantial increase in final costs. These plans serve as a crucial tool in achieving the decarbonization objectives of the European Power System.

Fractional-Differential Models of the Time Series Evolution of Socio-Dynamic Processes with Possible Self-Organization and Memory

This article describes the solution of two problems. First, based on the fractional diffusion equation, a boundary problem with arbitrary values of derivative indicators was formulated and solved, describing more general cases than existing solutions. Secondly, from the consideration of the probability schemes of transitions between states of the process, which can be observed in complex systems, a fractional-differential equation of the telegraph type with multiples is obtained (in time: β, 2β, 3β, … and state: α, 2α, 3α, …) using orders of fractional derivatives and its analytical solution for one particular boundary problem is considered. In solving edge problems, the Fourier method was used. This makes it possible to represent the solution in the form of a nested time series (one in time t, the second in state x), each of which is a function of the Mittag-Leffler type. The eigenvalues of the Mittag-Leffler function for describing states can be found using boundary conditions and the Fourier coefficient based on the initial condition and orthogonality conditions of the eigenfunctions. An analysis of the characteristics of time series of changes in the emotional color of users’ comments on published news in online mass media and the electoral campaigns of the US presidential elections showed that for the mathematical expectation of amplitudes of deviations of series levels from the size of the amplitude calculation interval (“sliding window”), a root dependence of fractional degree was observed; for dispersion, a power law with a fractional index greater than 1.5 was observed; and the behavior of the excess showed the presence of so-called “heavy tails”. The obtained results indicate that time series have unsteady non-locality, both in time and state. This provides the rationale for using differential equations with partial fractional derivatives to describe time series dynamics.

Scaling up innovation: European Innovation Council

The European Innovation Council (EIC) was launched in March 2021 and aims to help advance breakthrough innovations. To do so it has a funding budget of over €10 billion between 2021 and 2027. The EIC Board comprises entrepreneurs, researchers, investors, company representatives, along with other members of the innovation community, and is responsible for the EIC’s strategy, work programme and its implementation. Available funding is overseen by EIC Programme Managers who are experts in their field and aim to make innovations a reality by nurturing an environment where breakthroughs can truly blossom. The 2023 work programme includes three funding schemes; each designed to fit a particular project idea. Through the EIC Pathfinder scheme, €343 million is available to multifaceted research groups to facilitate innovative research. Candidates for this scheme are typically visionary scientists, entrepreneurial researchers, research performing organisations, start-ups, high-tech SMEs and groups and individuals with an interest in technology research and development. For research teams grants of up to €4 million are available to support technologies in the early stages of development. New technologies are supported and prepared for market by the EIC Transition scheme. Providing they can demonstrate that research results arising from Pathfinder and European Research Council Proof of Concept projects can be transformed into pioneering technologies and new businesses, applicants can access funding worth €128.3 million. If successful, applicants gain the opportunity to further develop their idea, produce a business plan and bring their innovation to market.

A Traceable Universal Designated Verifier Transitive Signature Scheme

A transitive signature scheme enables anyone to obtain the signature on edge (i,k) by combining the signatures on edges (i,j) and (j,k), but it suffers from signature theft and signature abuse. The existing work has solved these problems using a universal designated verifier transitive signature (UDVTS). However, the UDVTS scheme only enables the designated verifier to authenticate signatures, which provides a simple way for the signer to deny having signed some messages. The fact that the UDVTS is not publicly verifiable prevents the verifier from seeking help arbitrating the source of signatures. Based on this problem, this paper proposes a traceable universal designated verifier transitive signature (TUDVTS) and its security model. We introduce a tracer into the system who will trace the signature back to its true source after the verifier has submitted an application for arbitration. To show the feasibility of our primitive, we construct a concrete scheme from a bilinear group pair (G,GT) of prime order and prove that the scheme satisfies unforgeability, privacy, and traceability.

An ESOCVF-FLL Based Frequency Adaptive Two Loop Control Scheme for Seamless Transition of Microgrid Under Weak Grid Conditions

An ESOCVF-FLL Based Frequency Adaptive Two Loop Control Scheme for Seamless Transition of Microgrid Under Weak Grid Conditions

How connected is withholding capacity to electricity, fossil fuel and carbon markets? Perspectives from a high renewable energy consumption economy

As one kind of market power, withholding capacity infects the electricity, fossil fuel, and carbon markets. Withholding capacity is closely related to renewable energy consumption and is affected by major events. Considering major events and renewable energy consumption, we investigate the transmission mechanism between electricity, fossil fuel, carbon markets, and withholding capacity. Withholding capacity is characterized by time- and frequency-varying and event-triggered. We design a research framework to extract the dynamics of major events from time-frequency domains. The paper attempts to cover extreme scenarios (i.e., climate policy, extreme weather, public health, and global conflict) that exacerbate withholding capacity to the limits. This paper is the first to introduce the information spillover, exploring the transmission mechanism between withholding capacity and renewable energy consumption via time-frequency and major events perspectives. The results illustrate that (i) major events significantly affect the connectedness of withholding capacity to the electricity, fossil fuel, and carbon markets when renewable energy consumption is high; (ii) major events accelerate the shift in the transmission mechanism of withholding capacity from medium- and long-term to short-term timescales. Renewable energy consumption and major events challenge risk management. These findings contribute to designing structural and transitional emergency schemes in the low-carbon electricity market.

Robust conservative scheme and nonlinear solver for phase transitions in heterogeneous permafrost

In this paper we study computational schemes to simulate freezing and thawing in permafrost modeled by a nonlinear heat equation with constitutive properties resembling those in the well known Stefan problem but featuring distinct challenges. The models are discretized with low order conservative discretization and fully implicit time stepping. We explore the challenges due to the nonsmooth nature of the temperature–enthalpy relationship and the domain heterogeneity, with focus on the solver and the use of enthalpy as a primary variable in contrast to the temperature variable used commonly in applications literature. We prove and demonstrate the convergence of our algorithms in realistic physical scenarios.

Morphological variability of verbs in the methodological and aplicational contexts

Abstract The goal of our contribution is to find an adequate methodological platform for describing and explaining the so-called inter-paradigmatic transition of Slovak verbs from the conjugation prototype česať (“to comb”, 1483 lexemes) to the conjugation prototype chytať (“to catch”). This transition is not linear and smooth. We understand the description of the given phenomenon as the construction of a linguistic model – a “transition scheme” – based on systemic linguistics (specifically, functional and structural linguistics). This platform, with the concepts of function, norm, system, center, and periphery, is compatible with the cognitive concepts of prototype and continuum, which we include in the construction of the model as certain components of the user and practical dimensions. From the point of view of formal morphology, we rely most on the description system of Slovak conjugation by M. Sokolová (2019). We drew material from the Orthographic and Grammatical Dictionary and verified the occurrence of variants on the set of corpora Omnia Slovaca IV consisting of the Slovak National Corpus, specialized corpora and web corpora. We conclude that the goal of the analyzed cross-paradigmatic movement is not the transition of verbs from the prototype česať to the prototype chytať, but rather the optimal balance of definite and indefinite forms of each verb with regard to the defined conjugation prototype under the simultaneous interaction of pragmatic, frequency and phonological factors.