Model Theory Research Articles

The cycles agroecosystem model: Fundamentals, testing, and applications

Models of the soil–plant-atmosphere continuum are repositories of knowledge and gears in analytical and decision support tools applied to agroecosystems. In this paper, we present the Cycles agroecosystem model theory along with test cases and applications. Cycles combines innovations for simulating soil hydrology and biogeochemistry, including carbon and nitrogen saturation theory, with a modular software architecture. These elements enable simulating monoculture or polyculture crop sequences and associated management practices, containerizing for applications that require high-performance computing, and data assimilation at runtime. A comparison of simulated and measured daily evapotranspiration (ET) obtained with the eddy covariance method for maize (Zea mays L.) and shrub willow (Salix spp.) shows that Cycles represents well meteorological and vegetation controls of ET (root mean square error or RMSE = 0.75 mm d-1). Cycles accurately simulated differences of 150 mm in growing season ET between these two plant communities. Comparisons of modeled versus measured soil water content under soybean (Glycine max [L.] Merr.) in southeastern Pennsylvania for six soil layers at 0.1-m increments showed accurate representation of water depletion and recharge (RMSE of 0.027–0.011 m3 m−3). Simulations of growth and nitrogen uptake of wheat (Triticum aestivum L.) in eastern Washington also highlight the model’s skill simulating processes that affect water and nutrient fluxes simultaneously. To highlight Cycles’ suitability for incorporation in high performance computing applications, we present a coupling of Cycles with an autonomous crop sequence builder (Cycles-A) in the Chesapeake Bay watershed. This system automatically identified areas for double cropping and selected the optimum combination of annual crops across the watershed. The Cycles model innovations and agroecosystem framing continue advancing the premise of making models not only dynamic knowledge repositories but useful tools for research and landscape management.

A Conceptual Design Method based on C-K Theory and Large Language Models

A Conceptual Design Method based on C-K Theory and Large Language Models

Enhancing User Experience on Social Media Platforms: A Flow Theory-Based Approach

In recent years, social media platforms, such as Facebook and Twitter have seen rapid growth and are favored by users of all ages. However, in the age of information overload, the quality of interactions on social media platforms varies significantly, leading to negative feelings among users and affecting their overall experience and loyalty. This study takes the Flow theory as its starting point and investigates the needs of social media users at various stages of the flow experience. We propose modifications to the flow theory model with the aim of enhancing user experience and satisfaction. Firstly, based on literature review, we identify micro-level issues of the product, propose hypotheses, and construct validation experiments in the context of social media. The experiment collects Electrodermal Activity (EDA) and heart rate variability (HRV) data of 31 participants using a multi-channel physiological instrument and collects their emotional experience data using the Pleasure-Arousal-Dominance (PAD) scale. Results indicate that a combined textual-graphical interface layout is superior to other layouts in positively inducing flow and emotional experiences. Positive content tonality is more effective at eliciting positive flow and emotional experiences than negative or neutral content. Video presentations have a stronger sense of immersion and emotional expression, making them more conducive to inducing flow experiences and positive emotional feedback. This study, grounded in user psychology, provides a theoretical framework based on flow and emotional experiences for social media product design, quantitatively examining the positive psychological activities of users when using social media.

Validation of a French Version of the Visual Function and Corneal Health Status Instrument and Correlation With Vision and Glare Measurements in Fuchs Endothelial Corneal Dystrophy.

To validate a French version of the Visual Function and Corneal Health Status (V-FUCHS) instrument in Fuchs endothelial corneal dystrophy (FECD) and to correlate questionnaire scores with objective measurements of best-corrected visual acuity (BCVA) and intraocular straylight. The original V-FUCHS 15-item instrument was designed to assess VA and glare in patients with FECD. It was translated from English to French and back translated to English by independent translators. The questionnaire was administered on 2 occasions (4 weeks apart), and BCVA, modified Krachmer grade, and straylight were measured. Construct validity, internal consistency, test-retest reliability, and predictive validity were assessed. A total of 159 subjects, aged 41 to 86 years, were prospectively recruited from July 2019 to October 2020 and classified into 6 groups: mild, moderate, or advanced FECD; unilateral or bilateral Descemet membrane endothelial keratoplasty for FECD; and healthy controls (n = 35). Construct validity was confirmed by item response theory model. Cronbach alpha demonstrated excellent internal consistency (VA: 0.91, glare: 0.88), and intraclass correlations showed good test-retest reliability (VA: 0.75 and glare: 0.82). Significant correlations were observed between both VA and glare factors and the modified Krachmer grade, BCVA, and straylight. The proposed French version of the V-FUCHS instrument provides a valid and reliable tool for the assessment of visual disability in patients with FECD. This questionnaire bridges the gap between self-reported FECD symptoms and objective clinical measurements, which may prove useful to optimize the timing of surgery and to assess postoperative improvement in symptoms.

Empowering Unvaccinated Youth: Feasibility, Acceptability, and Efficacy of a COVID-19 Serious Game-Based Intervention.

Objective: To evaluate a serious game-based intervention's feasibility, acceptability, and efficacy in encouraging coronavirus disease (COVID-19) vaccination among 11-14-year-olds in the United States and assess participant experiences. Materials and Methods: The study, grounded in social cognitive theory and health belief model, recruited and engaged 32 English-speaking parent-child dyads with unvaccinated youths via snowball sampling and social media outreach. These dyads were randomly assigned to either the COVID-19 serious game-based intervention group (n = 16) or a usual caregroup (n = 16). The study measured beliefs, self-efficacy, and intentions regarding vaccination using surveys before and after the intervention, with follow-up at 2 months to evaluate vaccine uptake. Semistructured interviews provided insights into the gaming experience and study process. Results: All 32 eligible parent-youth dyads (16 in each group) completed the study with full participation. Most participants were Black or African American fathers, making up 75% and 81.3% of the intervention and control groups, respectively. The intervention impacted vaccine uptake, with 75% of the intervention group vaccinating their children compared with 37.5% of the control group [χ2(1, n = 32) = 4.57, P = 0.033]. Key factors for vaccine uptake included parents' motivation and youths' perceived susceptibility, with correlations of r(30) = 0.66, P = 0.006, and r(30) = 0.55, P = 0.029, respectively. The intervention reshaped youth perceptions about self and community protection. Participants expressed overall satisfaction with both the intervention and the study process. Conclusions: The intervention was found to be feasible and acceptable, with potential for integration into youth vaccination strategies to support COVID-19 vaccine decision-making.

Simultaneous inversion of four physical parameters of hydrate reservoir for high accuracy porosity estimation

AbstractEstimation of the porosity of a hydrate reservoir is essential for its exploration and development. However, the estimation accuracy was usually less certain in most previous studies that simply assumed that there is a linear relationship between the porosity and single‐elastic wave velocities or other rock physical parameters, thus affecting the evaluation of the reserves. In the three‐phase Biot‐type equations that are fundamental to model a hydrate‐bearing reservoir, porosity, alongside hydrate saturation, mineral constituent proportions and hydrate–grain contact factor, is non‐linearly responded by density, compressional and shear wave velocities. To improve porosity estimation, we propose to invert simultaneously four‐parameter (porosity, hydrate saturation, mineral constituent proportions and hydrate–grain contact factor) using an iteratively nonlinear interior‐point optimization algorithm to solve a nonlinear objective function that is a summation of the squared misfits between the well log and three‐phase Biot‐type equation–modelled density, compressional and shear wave velocities. A test in Mount Elbert gas hydrate research well was conducted for the case of a gas hydrate stratigraphic test well where elastic wave velocities, density, porosity and mineral composition analysis data are available. The four‐parameter inversion yielded a lower root mean square error for porosity (0.0245) across the entire well‐logging section compared to previous estimations from the linear relationship, post‐stacked and pre‐stacked seismic traces as well as the pore‐filling effective medium theory model applied to other well cases. Additionally, the other three parameters demonstrated good agreement with well logs. Inversion tests conducted at three additional hydrate sites also produced accurate results. Consequently, the new method surpasses previous approaches in porosity estimation accuracy.

Fault Diagnosis of Maritime Equipment Using an Intelligent Fuzzy Framework

The task of automatically and intelligently diagnosing faults in marine equipment is of great significance due to the numerous duties that shipboard professionals must handle. Incorporating automated and intelligent systems on ships allows for more efficient equipment monitoring and better decision-making. This approach has attracted considerable interest in both academia and industry because of its potential for economic savings and improved safety. Several fault diagnosis methods are documented in the literature, often involving mathematical and control theory models. However, due to the inherent complexity of some processes, not all characteristics are precisely known, making mathematical modeling highly challenging. As a result, fault diagnosis often depends on data or heuristic information. Fuzzy logic theory is particularly well suited for processing this type of information. Therefore, this paper employs fuzzy models to diagnose faults in a marine pneumatic servo-actuated valve. The fuzzy models used in fault diagnosis are obtained from the data. These fuzzy models are identified for the normal operation of the marine pneumatic servo-actuated valve, and for each fault, predicting the system’s outputs from the inputs and outputs of the process. The proposed fault diagnosis framework analyzes the discrepancy signals between the outputs of the fuzzy models and the actual process outputs. These discrepancies, known as residuals, help in detecting and isolating equipment faults. The fault isolation process uses an intelligent decision-making approach to determine the specific fault in the system. This method is applied to diagnose abrupt faults in a marine pneumatic servo-actuated valve. The approach presented was used to detect and diagnose three very important faults in the operation of a marine pneumatic servo-actuated valve. The three faults were correctly detected and isolated, and no errors were detected in this detection and isolation process.

Co-creation and evaluation of an algorithm for the development of a mobile application for wound care among new graduate nurses: A mixed methods study.

Chronic wounds are a growing concern due to aging populations, sedentary lifestyles and increasing rates of obesity and chronic diseases. The impact of such wounds is felt worldwide, posing a considerable clinical, environmental and socioeconomic challenge and impacting the quality of life. The increasing complexity of care requires a holistic approach, along with extensive knowledge and skills. The challenge experienced by health-care professionals is particularly significant for newly graduate nurses, who face a gap between theory and practice. Digital tools, such as mobile applications, can support wound care by facilitating more precise assessments, early treatment, complication prevention and better outcomes. They also aid in clinical decision-making and improve healthcare delivery in remote areas. Several mobile applications have emerged to enhance wound care. However, there are no applications dedicated to newly graduate nurses. The aim of this study was to co-create and evaluate an algorithm for the development of a wound care mobile application supporting clinical decisions for new graduate nurses. The development of this mobile application is envisioned to improve knowledge application and facilitate evidence-based practice. This study is part of a multiphase project that adopted a pragmatic epistemological approach, using the 'Knowledge-to-Action' conceptual model and Duchscher's Stages of Transition Theory. Following a scoping review, an expert consensus, and stakeholder meetings, this study was pursued through a sequential exploratory mixed methods design carried out in two phases. In the initial phase, 21 participants engaged in semi-structured focus groups to explore their needs regarding clinical decision support in wound care, explore their perceptions of the future mobile application's content and identify and categorize essential components. Through descriptive analysis, five overarching themes emerged, serving as guiding principles for conceptual data model development and refinement. These findings confirmed the significance of integrating a comprehensive glossary complemented by photos, ensuring compatibility between the mobile application and existing documentation systems, and providing quick access to information to avoid burdening work routines. Subsequently, the algorithm was created from the qualitative data collected. The second phase involved presenting an online SurveyMonkey® questionnaire to 34 participants who were not part of the initial phase to quantitatively measure the usability of this algorithm among future users. This phase revealed very positive feedback regarding the usability [score of 6.33 (±0.19) on a scale of 1-7], which reinforces its quality. The technology maturation process can now continue with the development of a prototype and subsequent validation in a laboratory setting.

Agelessness is possible under the disposable soma theory but system complexity makes it unlikely

Although demographic studies have failed to find evidence of aging in certain animal species, classic evolutionary theories of aging struggle to explain how evolution could favor agelessness in such cases. Here, we develop mathematical models of the disposable soma theory to identify conditions in which agelessness would be evolutionarily favored. For any given type of damage that could accumulate and cause age-accelerating mortality risk, we find that evolution could select for its complete removal if the mortality risk it poses is severe enough and its repair does not pose too large of a penalty to reproduction. Environmental factors such as extrinsic mortality and the form of population density-dependent regulation also play a large role in determining the optimal rate of aging and whether agelessness should be evolutionarily favored. However, in a system with multiple sources of damage and multiple independent repair processes, avoiding aging is rarely evolutionarily favorable. Pleiotropic repair processes, such as those that could be present in asexual fissioning organisms, make agelessness more likely but do not guarantee it. Our results indicate that agelessness could be favored by evolution in narrow contexts but that multiple types of damage and repair make agelessness unlikely to arise in sufficiently complex organisms.

Time-machines construct in f(ℛ, 𝒜, Aμν Aμν ) and f(ℛ) modified gravity theories

In this paper, our objective is to explore a time-machine space-time formulated in general relativity, as introduced by Li (Phys. Rev. D 59, 084016 (1999)), within the context of modified gravity theories. We consider Ricci-inverse gravity of all Classes of models, i.e., (i) Class-I: f(ℛ, 𝒜) = (ℛ + κℛ2 + β 𝒜), (ii) Class-II: f(ℛ, Aμν Aμν ) = (ℛ + κℛ2 + γ Aμν Aμν ) model, and (iii) Class-III: f(ℛ, 𝒜, Aμν Aμν ) = (ℛ + κℛ2 + β𝒜 + δ𝒜2 + γ Aμν Aμν ) model, where Aμν is the anti-curvature tensor, the reciprocal of the Ricci tensor, Rμν , 𝒜 = gμν Aμν is its scalar, and β, κ, γ, δ are the coupling constants. Moreover, we consider f(ℛ) modified gravity theory and investigate the same time-machine space-time. In fact, we show that Li time-machine space-time serve as valid solutions both in Ricci-inverse and f(ℛ) modified gravity theories. Thus, both theory allows the formation of closed time-like curves analogue to general relativity, thereby representing a possible time-machine model in these gravity theories theoretically.

Value-Positivity for Matrix Games

Matrix games are the most basic model in game theory, and yet robustness with respect to small perturbations of the matrix entries is not fully understood. In this paper, we introduce value positivity and uniform value positivity, two properties that refine the notion of optimality in the context of polynomially perturbed matrix games. The first concept captures how the value depends on the perturbation parameter, and the second consists of the existence of a fixed strategy that guarantees the value of the unperturbed matrix game for every sufficiently small positive parameter. We provide polynomial-time algorithms to check whether a polynomially perturbed matrix game satisfies these properties. We further provide the functional form for a parameterized optimal strategy and the value function. Finally, we translate our results to linear programming and stochastic games, where value positivity is related to the existence of robust solutions. Funding: This research was supported by Fondation CFM pour la Recherche, the H2020 European Research Council [Grant ERC-CoG-863818 (ForM-SMArt)], the Austrian Science Fund [Grant 10.55776/COE12], ANID Chile [Grant ACT210005], and Agence Nationale de la Recherche [Grant ANR-21-CE40-0020].

Mistakes in Thinking about Cognitive Science and How to Reduce Them.

This article allows readers to assess their ability to detect errors in thinking in seven case histories of psychologists' thoughts about cognitive science. It explains the nature of the errors and shows that some of them reflect faulty reasoning. It presents a "model method" to improve reasoning. It is based on the theory of mental models, which gives a general account of how individuals think, both deductively and indicatively, and which postulates that individuals construct mental models of possibilities in the world. The model method enhances both the accuracy and speed of reasoning. The article concludes with some general reflections on the role of knowledge of meanings, the world, and context in thinking.

Particle damping equivalent method based on force chain for high frequency vibration reduction: Mechanism analysis and experimental verification

A particle damping equivalent method based on force chain is newly proposed for simulating the behavior of particle damper (PD) with higher accuracy. Compared with other existing equivalent methods, this method considers the contact between particles and evaluates the particle motion state. Firstly, the particle damping equivalent method based on the theory of force chain and contact model is proposed, and the simulation process of the equivalent method is described. Then, this equivalent method is adopted to simulate the high frequency vibration of pipe installed with PD using SAP2000 software. The simulated vibration response exhibits excellent agreement with experimental results, validating the effectiveness of the proposed equivalent method. Finally, based on the calculation results, it is observed that the particle motion state of the PD in the experiment is quasi-static. This further shows that the particle chain in the damper under high frequency vibration can ignore the wave propagation behavior, which aligns with the assumption of the particle contact model.

Can Subsidy Policies Achieve Fuel Cell Logistics Vehicle (FCLV) Promotion Targets? Evidence from the Beijing-Tianjin-Hebei Fuel Cell Vehicle Demonstration City Cluster in China

Fuel cell logistics vehicle (FCLV) plays a pillar role in achieving carbon neutrality in the freight sector. Due to high costs and imperfect infrastructure, millions of subsidies are granted to develop FCLV and fulfill promotion targets set by the government. To examine the effectiveness of this action, the study proposes a tripartite evolutionary game theory (EGT) model to simulate the interactions between local governments, private investors, and consumers, and explores the fulfillment of promotion targets in the Beijing-Tianjin-Hebei fuel cell vehicle demonstration city cluster. The obtained results show that: (i) the FCLV promotion targets of demonstration cities except Tangshan could be substantially achieved under the current subsidy; (ii) purchase subsidies for consumers can help achieve promotion targets at a faster pace, while construction subsidies for investors have a limited incentive effect, so more non-financial incentives need to be provided to investors, such as innovative operating models and priority approval of land for hydrogen refueling station construction; (iii) a comparison of subsidies in different cities reveals that Beijing's subsidies are the most efficient and that there is an optimal allocation between consumers and private investors that allows for the faster accomplishment of promotion targets without increasing the fiscal burden.

Correlation of a single-item measure of financial toxicity with overall score.

351 Background: Financial toxicity (FT) refers to the financial burden experienced by patients due to direct and indirect costs associated with their medical care. It has been linked to higher symptom burden, poorer clinical outcomes, quality of life, and psychological well-being and has been shown to extend beyond diagnosis and treatment. Despite the availability of validated tools to measure FT, no single-item screening measure has been validated yet. In the context where time constraints are the most cited reason for patients declining FT surveys, it is crucial to develop efficient tools that allow us to routinely screen patients for FT at different stages of their care. We, therefore, sought to establish item 12 (“My illness has been a financial hardship to my family and me”) of the Comprehensive Score for Financial Toxicity (COST) measure as a well-functioning screening item for FT. Methods: In this secondary analysis of 579 patients who completed a survey on financial toxicity screening preferences, items 1-11 were scored (including reversing 7 items per the version 2 scoring guidelines), with lower scores indicating worse FT. Analyses focused on establishing a correlation with the total score as well as examining item properties. Item 12 was also reverse scored, so lower scores mean greater hardship. Results: Item 12 had an item-total correlation of r = 0.63 (adjusted item-total correlation = .531). Similarly, a linear model with item 12 score as a predictor and total score as the outcome showed that increases of 1 point on item 12 is associated with around 3 total points on the full scale (b = 3.35, p < .001, adjusted R 2 = 0.28. Finally, item analysis with the graded-response item response theory (IRT) model showed very good discrimination (a = 2.10) for item 12, indicating that it can reliably distinguish between low and high FT in patients. IRT results also showed that the item functions as a nearly binary item with responses of “quite a bit” and “very much” corresponding to a high probability of high FT, while responses of “somewhat,” “a little bit,” and “not at all” corresponding to a high probability of low FT. Conclusions: This is the first validation of a single-item screening measure for RT. Overall, these results illustrate that item 12 is a good candidate for a single-item screener, with “quite a bit” and “very much” responses indicating a high likelihood of high FT.

A wee exploration of techniques for risk assessments of extreme events

AbstractAssessing the behaviour of extreme events in univariate and multivariate settings entails many challenges, from the need to capture different sources of non-stationarity to adequately extrapolate into the tail of the distribution and compute probabilities of extreme events associated with high-dimensional vectors. Motivated by these common issues, we use a combination of methods from extreme-value theory, dimensionality reduction, non-parametric statistics, copula theory, and bootstrap model averaging to provide estimates of risk measures associated with environmental extremes. The work is tailored to the four data challenges presented in the EVA (2023) Conference Data Challenge competition, and the methods introduced here represent the approach taken by the Wee Extremes group.

Local Structure and Optical Studies of Mn2+ Doped L-histidine-4- nitrophenolate 4-nitrophenol Single Crystal

Background: The zero-field splitting parameters of Mn2+ doped L-histidine-4- nitrophenolate 4-nitrophenol single crystals are evaluated Methods: The superposition model and perturbation theory are used to obtain zero-field splitting parameters for Mn2+ ion-doped LHPP single crystals. The optical spectra of the system are computed using the crystal field parameters from the superposition model as input into the crystal field analysis program. Results: The evaluated zero field splitting parameters are in good match with the experimental values when local distortion is taken into account. The experimental finding that the Mn2+ ion enters the L-histidine-4-nitrophenolate 4-nitrophenol lattice at the interstitial position is supported by the theoretical result. Conclusion: It is found that the calculated and experimental band positions agree fairly well. Thus, the theoretical study supports the experimental observation.

The Feasibility of Asynchronous Rotation via Thermal Tides for Diverse Atmospheric Compositions

The equilibrium rotation rate of a planet is determined by the sum of torques acting on its solid body. For planets with atmospheres, the dominant torques are usually the gravitational tide, which acts to slow the planet’s rotation rate, and the atmospheric thermal tide, which acts to spin up the planet. Previous work demonstrated that rocky planets with thick atmospheres may produce strong enough thermal tides to avoid tidal locking, but a study of how the strength of the thermal tide depends on atmospheric properties has not been done. In this work, we use a combination of simulations from a global climate model and analytic theory to explore how the thermal tide depends on the shortwave and longwave optical depth of the atmosphere, the surface pressure, and the absorbed stellar radiation. We find that for planets in the habitable zones of M stars only high-pressure but low-opacity atmospheres permit asynchronous rotation owing to the weakening of the thermal tide at high longwave and shortwave optical depths. We conclude that asynchronous rotation may be very unlikely around low-mass stars, which may limit the potential habitability of planets around M stars.

The acceptance of social media as a channel of communication and livestock information for sheep farmers

Abstract The development of technology and information in the Industry 4.0 era, especially the internet, is experiencing very rapid progress. Searching for information through new media will increase human resource capacity and work efficiency. Using technology acceptance model (TAM) theory, this study aims to identify social media usage as a communication and information medium and analyze the influence between constructs in social media acceptance. A cross-sectional survey was used in this study design. A structured questionnaire from previous related studies was used as the instrument. One hundred and eleven sheep farmers from several villages in Sukabumi, West Java groups, participated in this survey. Stratified sampling was adopted to select and interview the respondents. The findings show that social media usage as a channel for communication and livestock information is quite adequate. Many farmers already use WhatsApp and YouTube. However, only a few farmers use Facebook and Instagram. The results of the TAM analysis (limited to only the WhatsApp application) indicate that perceived ease of use positively influences perceived usefulness (PU). A positive relationship is also shown between PU and behavioral intention to use. The theoretical implication is that this study proves how social media adopts in disseminating messages and seeking information. Regarding managerial implications, the findings suggest that stakeholders in the agricultural industry across the value chain could enhance their services by fostering a broader ecosystem of social media applications.

Evaluation of habitat suitability and migratory paths of an endangered raptor, Steppe Eagle (Aquila nipalensis) in Iran

Understanding habitat suitability, the environmental variables limiting the distribution of species, and migratory paths are important issues for conservation of threatened bird species. Identifying areas important for birds and their overlap with conservation areas (CAs) can guide conservation managers in establishing new CAs. The Steppe Eagle (Aquila nipalensis) is a globally endangered winter visitor raptor in Iran. We used 164 occurrence records of Steppe Eagles and data on 12 environmental variables in Iran as input to ensemble modeling and electrical circuit theory models to identify, respectively, potential wintering areas and migratory paths between those wintering areas. Our results revealed that elevation, distance to rodents, mean diurnal range, distance to villages, and distance to cities were the most influential variables for habitat suitability in Iran. Potential wintering areas identified by our models were mainly located in the north and south of Iran and migratory paths connected these areas through the central plains. CAs covered about one-fifth of potential wintering areas. Conservation of the species within potential wintering areas and the migratory paths from northern to southern Iran is necessary for the survival of this endangered species in its entire distribution. Therefore, wildlife managers should pay increased attention to non-protected parts of potential wintering areas in order to establish new CAs and protect migration paths against threats. Our results pave the way for proper planning for the conservation of threatened raptors in Iran, particularly Steppe Eagle.