Functional Model Research Articles

An energy model for harmonic functions with junctions

We consider an energy model for harmonic graphs with junctions and study the regularity properties of minimizers and their free boundaries.

Thin Film Resistance Gating by Redox Charge Exchange: Evidence for a Quantum Transition State.

Field effect transistors (FETs) and related devices have enabled tremendous advances in electronics, as well as studies of fundamental phenomena. FETs are classically actuated as fields charge/discharge materials, thereby modifying their resistance. Here, we develop charge exchange transistors (CETs) that comprise thin films whose resistance is modified by quantum charge exchange processes, e.g., redox and bonding. We first use CETs to probe the metallocene-thin film interaction during cyclic voltammetry. Remarkably, CETs reveal transient resistance peaks associated with charge transfer during both oxidation and reduction. Our data combined with kinetics and density functional theory modeling are consistent with a multistep redox pathway, including the formation/destruction of a quantum transition state that overlaps molecule + thin film band states. As a further proof-of-principle demonstration, we also use CETs to monitor n-alkanethiol self-assembly on thin Au films in real-time. CETs exhibit monotonic resistance increase consistent with previously reported fast-then-slow kinetics attributed to thiol-thin film bond formation (charge localization) and etching and/or molecule reorganization.

A selective discussion on oxo-bridged diiron (III,III) centers in chemistry related to bio-functional activity

Diiron (III, III) oxo- bridged core is playing significant role in various biologically active compounds. Several synthetic diiron compounds are prepared which are the structural and functional models of these bio active centers. Extensive study over these compounds helps us to gain an idea about the mechanistic pathways adopted in the bio active centers. In vivo studies are highly expensive and critical. Analysis of these complexes outside the bio-environment is comparatively simple but give us an idea about the mechanistic overview of the metal centers which guide us for further proceedings.

"Ectomycorrhizal exploration type" could be a functional trait explaining the spatial distribution of tree symbiotic fungi as a function of forest humus forms.

In European forests, most tree species form symbioses with ectomycorrhizal (EM) and arbuscular mycorrhizal (AM) fungi. The EM fungi are classified into different morphological types based on the development and structure of their extraradical mycelium. These structures could be root extensions that help trees to acquire nutrients. However, the relationship between these morphological traits and functions involved in soil nutrient foraging is still under debate.We described the composition of mycorrhizal fungal communities under 23 tree species in a wide range of climates and humus forms in Europe and investigated the exploratory types of EM fungi. We assessed the response of this tree extended phenotype to humus forms, as an indicator of the functioning and quality of forest soils. We found a significant relationship between the relative proportion of the two broad categories of EM exploration types (short- or long-distance) and the humus form, showing a greater proportion of long-distance types in the least dynamic soils. As past land-use and host tree species are significant factors structuring fungal communities, we showed this relationship was modulated by host trait (gymnosperms versus angiosperms), soil depth and past land use (farmland or forest).We propose that this potential functional trait of EM fungi be used in future studies to improve predictive models of forest soil functioning and tree adaptation to environmental nutrient conditions.

Density functional model of threshold voltage shifts at High-K/Metal gates

A density functional analysis of oxide dipole layers used to set the threshold voltages in high-K/metal CMOS gate stacks is given in terms of the band alignments and chemical trends of these component oxide layers. The oxides SrO, La2O3, HfO2 and Al2O3 are found to have similar band gaps and form a ‘staircase’ of band alignments, allowing them to shift the metal electrode Fermi level in both n-type and p-type directions. This analysis supersedes previous largely empirical models based on metal oxide ion densities or electronegativity scales.

Anhedonia as a potential transdiagnostic phenotype with immune-related changes in recent onset mental health disorders

BackgroundChronic low-grade inflammation is observed across mental disorders and is associated with difficult-to-treat-symptoms of anhedonia and functional brain changes – reflecting a potential transdiagnostic dimension. Previous investigations have focused on distinct illness categories in those with enduring illness, with few exploring inflammatory changes. We sought to identify an inflammatory signal and associated brain function underlying anhedonia among young people with recent onset psychosis (ROP) and recent onset depression (ROD). MethodResting-state functional magnetic resonance imaging, inflammatory markers, and anhedonia symptoms were collected from N=108 (M age=26.2[SD 6.2]years; Female =50) participants with ROP (n=53) and ROD (n=55) from the EU-FP7-funded PRONIA study. Time-series were extracted using the Schaefer atlas, defining 100 cortical regions of interest. Using advanced multimodal machine learning, an inflammatory marker model and functional connectivity model were developed to classify an anhedonic group, compared to a normal hedonic group. ResultsA repeated nested cross-validation model using inflammatory markers classified normal hedonic and anhedonic ROP/ROD groups with a balanced accuracy (BAC) of 63.9%, and an area under the curve (AUC) of 0.61. The functional connectivity model produced a BAC of 55.2% and an AUC of 0.57. Anhedonic group assignment was driven by higher levels of Interleukin-6, S100B, and Interleukin-1 receptor antagonist, and lower levels of Interferon gamma, in addition to connectivity within the precuneus and posterior cingulate. ConclusionWe identified a potential transdiagnostic anhedonic subtype that was accounted for by an inflammatory profile and functional connectivity. Results have implications for anhedonia as an emerging transdiagnostic target across emerging mental disorders.

Method of successive approximation in mathematical modelling of geotechnical mechanics problems

The purpose of this work was to develop a mathematical model by the results of mathematical modeling of the problem of loading a circular cross-sectional roadway under the action of hydrostatic pressure. Instead of finite element method, it proposed to solve this problem by method of successive approximation, which assumes finding a solution in vicinity of one point in the domain of definition in a multiplicative form where the product functions are one-dimensional functions of parameters. Such representation advantageously differs from classical representation of approximation results by visualization and convenience and by possibility to investigate function sensitivity to the parameter variation. The obtained model provides errors of 5-7%. The results of qualitative comparison of volumetric functions of the tangential stress intensity obtained by the successive approximation method with the representation of numerical results of solving the chosen classical problem presented. Mathematical models of the tangential stresses intensity function in vicinity of a roadway in analytical form are obtained. It is proposed to use this method for representing mathematical models in analytical form and determining function sensitivity to the parameter variation in the problems of geotechnical mechanics. The effectiveness of the method increases when analyzing results of multiparametric problems.

The time course of motor and cognitive decline in older adults and their associations with brain pathologies: a multicohort study

Many studies have reported that impaired gait precedes cognitive impairment in older people. We aimed to characterise the time course of cognitive and motor decline in older individuals and the association of these declines with the pathologies of Alzheimer's disease and related dementias. This multicohort study used data from three community-based cohort studies (Religious Orders Study, Rush Memory and Aging Project, and Minority Aging Research Study, all in the USA). The inclusion criteria for all three cohorts were no clinical dementia at the time of enrolment and consent to annual clinical assessments. Eligible participants consented to post-mortem brain donation and had post-mortem pathological assessments and three or more repeated annual measures of cognition and motor functions. Clinical and post-mortem data were analysed using functional mixed-effects models. Global cognition was based on 19 neuropsychological tests, a hand strength score was based on grip and pinch strength, and a gait score was based on the number of steps and time to walk 8 feet and turn 360°. Brain pathologies of Alzheimer's disease and related dementias were assessed at autopsy. From 1994 to 2022, there were 1570 eligible cohort participants aged 65 years or older, 1303 of whom had cognitive and motor measurements and were included in the analysis. Mean age at death was 90·3 years (SD 6·3), 905 (69%) participants were female, and 398 (31%) were male. Median follow-up time was 9 years (IQR 5-11). On average, cognition was stable from 25 to 15 years before death, when cognition began to decline. By contrast, gait function and hand strength declined during the entire study. The combinations of pathologies of Alzheimer's disease and related dementias associated with cognitive and motor decline and their onsets of associations varied; only tau tangles, Parkinson's disease pathology, and macroinfarcts were associated with decline of all three phenotypes. Tau tangles were significantly associated with cognitive decline, gait function decline, and hand function decline (p<0·0001 for each); however, the association with cognitive decline persisted for more than 11 years before death, but the association with hand strength only began 3·57 years before death and the association with gait began 3·49 years before death. By contrast, the association of macroinfarcts with declining gait function began 9·25 years before death (p<0·0001) compared with 6·65 years before death (p=0·0005) for cognitive decline and 2·66 years before death (p=0·024) for decline in hand strength. Our findings suggest that average motor decline in older adults precedes cognitive decline. Macroinfarcts but not tau tangles are associated with declining gait function that precedes cognitive decline. This suggests the need for further studies to test if gait impairment is a clinical proxy for preclinical vascular cognitive impairment. National Institutes of Health.

Current strategies using 3D organoids to establish in vitro maternal-embryonic interaction.

The creation of robust maternal-embryonic interactions and implantation models is important for comprehending the early stages of embryonic development and reproductive disorders. Traditional two-dimensional (2D) cell culture systems often fail to accurately mimic the highly complex in vivo conditions. The employment of three-dimensional (3D) organoids has emerged as a promising strategy to overcome these limitations in recent years. The advancements in the field of organoid technology have opened new avenues for studying the physiology and diseases affecting female reproductive tract. This review summarizes the current strategies and advancements in the field of 3D organoids to establish maternal-embryonic interaction and implantation models for use in research and personalized medicine in assisted reproductive technology. The concepts of endometrial organoids, menstrual blood flow organoids, placental trophoblast organoids, stem cell-derived blastoids, and in vitro-generated embryo models are discussed in detail. We show the incorportaion of organoid systems and microfluidic technology to enhance tissue performance and precise management of the cellular surroundings. This review provides insights into the future direction of modeling maternal-embryonic interaction research and its combination with other powerful technologies to interfere with this dialogue either by promoting or hindering it for improving fertility or methods for contraception, respectively. The merging of organoid systems with microfluidics facilitates the creation of sophisticated and functional organoid models, enhancing insights into organ development, disease mechanisms, and personalized medical investigations.

We Accept: Bit-by-bit Constitution

Abstract In “We Accept: The Constitution of Airbnb”, published in 2020, I drew on Gunther Teubner’s systems theoretical approach, including to digitalisation and societal constitutionalism, to rethink Airbnb as an auto-constitutionalising domain. This dynamic process, the paper proceeded to suggest, instantiates a structural change, what can be described, in systems theoretical terms, as a “co-evolution” of multiple social systems through structural couplings. It renders observable an “emergence” of a general model of functioning – terms of use and engagement – epitomised by a reconceptualisation of the “social contract” as a network of “standard form contracts” or “contracts of adhesion”, and of an increasingly dominant mode of subjectivation: the standard formation or auto-constitution of subjects as adherents. In this new contribution, I continue this processing of social systems theory and Teubner’s work, this time through a deconstruction and reconstruction of Internet communication. Through this recursive illustration of social systems theory and Teubner’s work, the paper develops a social systems theoretical account of “process”, “constitution”, and “structural change”.

Development of innovative processes in the field of agriculture of the Republic of Kazakhstan

Agriculture remains an important component of Kazakhstan's development, creating a significant part of the country's GDP. However, it still requires finding new opportunities to increase the efficiency of its functioning. Thus, the purpose of the work was to analyse the possibility of developing agriculture in the Republic of Kazakhstan, namely, with the help of innovations. The main method used in writing the article can be considered modelling, taking into account the number of models of functioning of state regulation in the country built in the work to improve innovation processes in the country. Other methods include analysis, induction, comparison, and others. This paper substantiates the need to improve state regulation in the field of innovation in agriculture of the Republic of Kazakhstan, and also describes the likely directions of development in this direction. In connection with the existing shortcomings in the management system, models of state support for enterprises in the agricultural sector were developed and proposed for the development of innovation in the industry. The presented models provide the possibility of using modern tools for regulating processes, taking into account a systematic approach, which ensures the coordination of actions of the relevant authorities to ensure both private and national interests. The main difference between the models proposed in the work and those existing in the Republic of Kazakhstan is the presence of a single centre that is fully responsible for the development of agriculture at the local and national levels, and ensures the achievement of an increase in innovation in it. Thus, the work allows re-evaluating the existing methods of agricultural development, and also brings new knowledge to the formation of the principles of public administration

New combination of methods for supporting a simplified set-based design approach

AbstractThis work presents a Set-Based Design inspired approach for generation, evaluation and reduction of a solution space of alternative product concepts. Also, the aspect of how to implement the process in an industrial environment was investigated. The hypothesis, confirmed by case studies, is that it can be done using existing methods like Enhanced functional modelling, brainwriting, the Gallery method, Axiomatic Design, causal diagrams and Pugh matrices. The method can be successfully introduced in a timeframe of a few working days and support development engineers in the concept design phase.

Development of a capillary temperature control system for capillary electrophoresis instruments designed for spaceflight applications.

Capillary temperature control during capillary electrophoresis (CE) separations is key for achieving accurate and reproducible results with a broad array of potential methods. However, the difficulty of enabling typical fluid temperature control loops on portable instruments has meant that active capillary temperature control of in situ CE systems has frequently been overlooked. This work describes construction and test of a solid-state device for capillary temperature control that is suitable for inclusion with in situ instruments, including those designed for space missions. Two test articles were built, a thermal mass model (TMM) and a functional model (FM). The TMM demonstrated that temperature gradients could be limited using the proposed control scheme, and that our thermal modeling of the system can be relied on for future adaptations of physical geometries of the system. The FM demonstrated CE analytical performance while under active temperature control and that the device was compatible with the harsh thermal-vacuum environments that might be encountered during space flight.

A hybrid prognostic & health management framework across multi-level engineering systems with scalable convolution neural networks and adjustable functional regression models

With the rapid development of sensor technology and mechatronics integration, there are emerging demands for achieving prognostic and health management (PHM) within a general framework across multi-level engineering systems. However, current PHM frameworks are mainly supported either by field data or degradation models, which are always limited in inadequate robustness to systematically increase operational availability and reduce maintenance costs. For extending the scalability and flexibility of PHM services, this paper proposes a novel hybrid framework that integrates the scalable convolution neural network (SCNN) with the adjustable functional regression model (AFRM) through a modified linear filter. This proposed framework first establishes a data-driven SCNN with scalable time sequences and kernel sizes to enhance the remaining useful life (RUL) generalization. Then, enabled by an adjustable semi-parametric degradation process model, AFRM with flexible lifetime distributions is designed to evaluate time-to-failure (TTF) in real time. Finally, a modified Kalman filter has been explored to coordinate data-driven RUL results with model-based TTF values to schedule predictive maintenance (PdM). High-accuracy prediction, multi-level systems, high-flexibility evaluation are thus encompassed within the hybrid progressive modification. The proposed framework has been practically validated through multi-level studies including the component-level bearings, subsystem-level engines, and system-level machines. Results demonstrate that our hybrid PHM framework achieves significant improvements in prediction accuracy, evaluation adaptability, and scheduling effectiveness.

On the convergence of gradient descent for robust functional linear regression

Functional data analysis offers a set of statistical methods concerned with extracting insights from intrinsically infinite-dimensional data and has attracted considerable amount of attentions in the past few decades. In this paper, we study robust functional linear regression model with a scalar response and a functional predictor in the framework of reproducing kernel Hilbert spaces. A gradient descent algorithm with early stopping is introduced to solve the corresponding empirical risk minimization problem associated with robust loss functions. By appropriately selecting the early stopping rule and the scaling parameter of the robust losses, the convergence of the proposed algorithm is established when the response variable is bounded or satisfies a moment condition. Explicit learning rates with respect to both estimation and prediction error are provided in terms of regularity of the regression function and eigenvalue decay rate of the integral operator induced by the reproducing kernel and covariance function.

FEATURES OF USING INTERACTIVE TECHNOLOGIES FOR IMPLEMENTING PERSONALIZED LEARNING IN BIOLOGY AND ECOLOGY CLASSES IN THE 10th GRADE

application of interactive technologies to realize personalized learning in biology and ecology classes in the 10th grade. This methodology comprises three main stages: organizational-preparatory, technological, and concluding. Pedagogical conditions are justified for the effective implementation of the respective methodology, including creating a success-oriented situation, organizing a positive psychological microclimate, gearing up for work, motivating students’ cognitive activities, equipping the classroom, providing visualization aids for the lesson, selecting effective methods of communication and instructional interaction, discussing the action algorithm during work, reviewing assessment criteria, reflection, and summarizing.Based on the above, a functional model for the implementation of the developed methodology is proposed. On the basis of the above, a functional model for the formation of a successful student in education, who will achieve high levels of academic achievement in biology and ecology when using personalized learning with interactive technology, is proposed. The functional model for the formation of a successful student in education, who will achieve high levels of academic achievement in biology and ecology when using personalized learning with interactive technology, is based on a scientific approach to organizing the educational process.The main goal of this model is the effective implementation of personalized learning with the use of interactive technologies, which allows for the formation of a successful student on the basis of student-centeredness, which is the driving force behind raising the level of academic achievement in biology and ecology.

USING SOLAR ENERGY AS NON-CONVENTIONAL ALTERNATIVE ENERGY IN SMALL AND MEDIUM-SIZED FARMS (Part II)

Considering that every day the sun generates more energy than the planet needs for daily consumption, harnessing solar energy represents one of the future solutions for clean, sustainable energy, obviously with the technological limitations related to the ability to transform this energy into electricity. The paper presents a functional model of equipment that allows the capture of solar energy using special panels, which can rotate both horizontally and vertically according to the sun, so that the incidence of rays with the radiating surface of the panels is maximum and the yields obtained at different angles of inclination in the vertical plane at 60, respectively in the horizontal plane at 0o.

UTILIZAREA ENERGIEI SOLARE CA SURSĂ ALATERNATIVĂ NECONVENŢIONALĂ DE ENERGIE ÎN FERMELE DE DIMENSIUNI MICI ŞI MEDII

Solar energy represents a future solution for clean, sustainable energy, because the sun generates much more energy every day than it is necessary for daily consumption, unlike fossil fuels. The only limitation related to this renewable resource is the ability to transform this energy into electricity. The paper presents a functional model of equipment that allows the capture of solar energy using special panels, which can rotate according to the sun, so that the incidence of rays with the radiating surface of the panels is maximum, and the yields obtained at different angles of inclination (in the vertical plane: 30 and 45, and in the horizontal plane: 0 to be maximum.

ASPECTE PRIVIND UTILIZAREA ENERGIEI SOLARE ÎN FERMELE MICI ŞI MEDII

Considering that every day the sun generates more energy than the planet needs for daily consumption, harnessing solar energy represents one of the future solutions for clean, sustainable energy, obviously with the technological limitations related to the ability to transform this energy into electricity. The paper presents a functional model of equipment that allows the capture of solar energy using special panels, which can rotate both horizontally and vertically according to the sun, so that the incidence of rays with the radiating surface of the panels is maximum and the yields obtained at different angles of inclination in the vertical plane at 60, respectively in the horizontal plane at 0o.

Deriving Dependently-Typed OOP from First Principles

The expression problem describes how most types can easily be extended with new ways to produce the type or new ways to consume the type, but not both. When abstract syntax trees are defined as an algebraic data type, for example, they can easily be extended with new consumers, such as print or eval , but adding a new constructor requires the modification of all existing pattern matches. The expression problem is one way to elucidate the difference between functional or data-oriented programs (easily extendable by new consumers) and object-oriented programs (easily extendable by new producers). This difference between programs which are extensible by new producers or new consumers also exists for dependently typed programming, but with one core difference: Dependently-typed programming almost exclusively follows the functional programming model and not the object-oriented model, which leaves an interesting space in the programming language landscape unexplored. In this paper, we explore the field of dependently-typed object-oriented programming by deriving it from first principles using the principle of duality. That is, we do not extend an existing object-oriented formalism with dependent types in an ad-hoc fashion, but instead start from a familiar data-oriented language and derive its dual fragment by the systematic use of defunctionalization and refunctionalization. Our central contribution is a dependently typed calculus which contains two dual language fragments. We provide type- and semantics-preserving transformations between these two language fragments: defunctionalization and refunctionalization. We have implemented this language and these transformations and use this implementation to explain the various ways in which constructions in dependently typed programming can be explained as special instances of the general phenomenon of duality.