Graph functional dependencies: Analysis and translation to PG-schema

The theory of functional and template dependencies

Armstrong databases for functional and inclusion dependencies

Functional dependencies (FDs) and candidate keys are essential for table decomposition,database normalization, and data cleansing. In this paper, we present FDTool, a commandline Python application to discover minimal FDs in tabular datasets and infer equivalent attributesets and candidate keys from them. The runtime and memory costs associated withseven published FD discovery algorithms are given with an overview of their theoretical foundations.We conclude that FD_Mine is the most efficient FD discovery algorithm when appliedto datasets with many rows (> 100,000 rows) and few columns (< 14 columns). This putsit in a special position to rule mine clinical and demographic datasets, which often consistof long and narrow sets of participant records. The structure of FD Mine is described andsupplemented with a formal proof of the equivalence pruning method used. FDTool is are-implementation of FD Mine with additional features added to improve performance andautomate typical processes in database architecture. The experimental results of applyingFDTool to 12 datasets of different dimensions are summarized in terms of the number ofFDs checked, the number of FDs found, and the time it takes for the code to terminate. Wefind that the number of attributes in a dataset has a much greater effect on the runtime andmemory costs of FDTool than does row count. The last section explains in detail how theFDTool application can be accessed, executed, and further developed.

The Percus-Yevick integral equation has been solved for hard spherocylinders, using an algorithm introduced in a previous paper. The pair correlation function (PCF) and the direct correlation function have been obtained and the dependence of these functions on the elongation as well on the numerical density is presented. Some of the spherical harmonic coefficients corresponding to the PCF are also shown and compared with Monte Carlo simulations. The best agreement is obtained for intermediate elongations, corresponding to molecules such as Cl2 and for the first harmonic coefficient. The variation of the PCF of selected orientations with density is similar to that of hard spheres. Nevertheless, the variation for each orientation with elongation is more complicated trending to the hard sphere limit in different ways.

Functional dependencies (FDs) specify the intended data semantics while violations of FDs indicate deviation from these semantics. In this paper, we study a data cleaning problem in which the FDs may not be completely correct, e.g., due to data evolution or incomplete knowledge of the data semantics. We argue that the notion of relative trust is a crucial aspect of this problem: if the FDs are outdated, we should modify them to fit the data, but if we suspect that there are problems with the data, we should modify the data to fit the FDs. In practice, it is usually unclear how much to trust the data versus the FDs. To address this problem, we propose an algorithm for generating non-redundant solutions (i.e., simultaneous modifications of the data and the FDs) corresponding to various levels of relative trust. This can help users determine the best way to modify their data and/or FDs to achieve consistency.

© 2017 ACM. Functional dependencies are a popular extension to Haskell's typeclass system because they provide fine-grained control over type inference, resolve ambiguities and even enable type-level computations. Unfortunately, several aspects of Haskell's functional dependencies are ill-understood. In particular, the GHC compiler does not properly enforce the functional dependency property, and rejects well-typed programs because it does not know how to elaborate them into its core language, System F C . This paper presents a novel formalization of functional dependencies that addresses these issues:We explicitly capture the functional dependency property in the type system, in the form of explicit type equalities. We also provide a type inference algorithm and an accompanying elaboration strategy which allows all well-typed programs to be elaborated into System F C .

One of the challenges post-COVID-19 is reducing the negative impacts on quality of life, performance, and independence in activities of daily living. Assessing functional dependence in adults one year after acute infection can help to understand the long-term consequences, evaluate the impact on quality of life, plan rehabilitation and healthcare, identify the most vulnerable groups, measure the socioeconomic impact, and support public policies and clinical decisions. Objectives: The objectives of this study are as follows: (a) to assess the prevalence of functional dependence in Brazilian adults with COVID-19; (b) to analyze the association between the study variables; and (c) to determine the factors associated with functional dependence. Methods: This was an observational, cross-sectional study with 987 adults (18 to 59 years old) living in the State of Paraná (Brazil) hospitalized for COVID-19 between March and December 2020. Data were collected by telephone 12 months after the acute infection using an instrument to retrieve sociodemographic and health information, and a functional dependence scale to assess dependence before COVID-19 retrospectively (using participant recall information) and at the time of the interview. Data were analyzed using penalized logistic regression after imputing missing data. Data were analyzed using penalized logistic regression after imputing missing data. Results: Functional dependence after COVID-19 was 5.0% and was associated with low levels of education, not having a partner, living with someone, not owning a home, experiencing job changes, requiring care, obesity, smoking, multimorbidity, ICU admission in the acute phase, use of invasive ventilation, or having Long COVID. Individuals who required care or used invasive ventilation support were, respectively, 9.3 and 6.5 times more likely to develop dependence after COVID-19. Despite adjustment for multiple factors, the magnitude of the observed effects warrants cautious interpretation, as unmeasured or residual confounding effects may still be present. Sample recall bias due to collection after 12 months and the presence of the alpha variant without COVID-19 vaccination coverage may limit data generalization. Conclusions: The results highlight the need to emphasize the public health implications of identifying functional dependence. In this vein, it is necessary to implement preventive measures, identify and monitor more vulnerable groups, plan rehabilitation programs, and develop public health policies.

Taking domain knowledge into account is a long-standing issue in AI, especially nowadays where huge amounts of data are collected in the hope of delivering new in-sights and value. Let us consider the following scenario. Let D(y, x1, &#x2026; ,x<inf>n</inf>) be a dataset, Alice a data scientist, Bob a domain expert and <tex>$y$</tex> &#x003D; <tex>$f$</tex> (x1, &#x2026; , xn) a function known by Bob from his background knowledge. We are interested in the following simple yet crucial questions for Alice: how to define the satisfaction of f in D and how difficult is it to measure that satisfaction? It turns out that those problems are related to functional dependencies (FDs) and especially FD measurements used to quantify their satisfaction in a dataset such as the g3 indicator. In this paper, we examine the computation of g3 with crisp FDs (aka. exact FDs) and a large class of non-crisp FDs replacing strict equality by more flexible predicates. Interestingly, it is known that the computation of g3 with crisp FDs is polynomial but turns out to be NP-Hard for non-crisp FDs. In this paper, we propose different exact and approximate solutions for the computation of g3 for both types. First, for crisp FDs with very large datasets, we propose solutions based on uniform and stratified random sampling. Second, for non-crisp FDs we present a detailed computation pipeline with various computation optimizations, including approximation algorithms and adaptations of recent developments in sublinear algorithms for NP-Hard problems. We also propose an in-depth experimental study of the algorithms presented in terms of time performances and approximation accuracy. All the algorithms are also made available through FASTG3, an open-source Python library designed to be intuitive and efficient thanks to an underlying C++ implementation.

The adverse impacts of lead and cadmium exposure on health outcomes have been reported in the past. Few studies have been conducted on the relationship between lead and cadmium exposures and disability. We evaluated whether lead and cadmium exposures were associated with functional dependence including the total number of disabilities, activities of daily living (ADL), instrumental activities of daily living (IADL), leisure and social activities (LSA), lower extremity mobility (LEM), and general physical activities (GPA) in an elderly population. A total of 5513 eligible subjects were enrolled in the study from the National Health and Nutrition Examination Survey 2001-2006. Serum lead and cadmium exposure assessments were performed using atomic absorption spectrometry. Functional dependence was assessed by 19 structured questions. The relationships between lead and cadmium exposures and functional dependence were investigated using by multivariable linear regression models. Q2, Q3, and Q4 of lead exposure were significantly associated with the total number of disabilities, with β coefficients of - 0.62 (95% CI - 0.99, - 0.24), - 0.64 (95% CI - 1.02, - 0.26), and - 0.81 (95% CI - 1.19, - 0.42), respectively. This relationship remained significant in males. Furthermore, we analyzed the relationships between lead and cadmium exposure quartiles and various functional dependence metrics, and we determined that lead content was significantly associated with decreased ADL, LEM, and GPA (p < 0.05) and cadmium content was inversely associated with ADL (p < 0.05). Our study demonstrated a strong relationship between exposure to lead and cadmium and functional dependence in an elderly population.

Disability among long-term methamphetamine (MA) users is multifactorial. This study examined the additive adverse impact of human immunodeficiency virus (HIV) infection, a common comorbidity in MA users, on functional dependence. A large cohort of participants (N = 798) stratified by lifetime MA-dependence diagnoses (ie, MA+ or MA-) and HIV serostatus (ie, HIV+ or HIV-) underwent comprehensive baseline neuromedical, neuropsychiatric, and functional research evaluations, including assessment of neurocognitive symptoms in daily life, instrumental and basic activities of daily living, and employment status. Independent, additive effects of MA and HIV were observed across all measures of functional dependence, independent of other demographic, psychiatric, and substance-use factors. The prevalence of global functional dependence increased in the expected stepwise fashion across the cohort, with the lowest rates in the MA-/HIV- group (29%) and the highest rates in the MA+/HIV+ sample (69%). The impact of HIV on MA-associated functional dependence was moderated by nadir CD4 count, such that polysubstance use was associated with greater disability among those HIV-infected persons with higher but not lower nadir CD4 count. Within the MA+/HIV+ cohort, functional dependence was reliably associated with neurocognitive impairment, lower cognitive reserve, polysubstance use, and major depressive disorder. HIV infection confers an increased concurrent risk of MA-associated disability, particularly among HIV-infected persons without histories of immune compromise. Directed referrals, earlier HIV treatment, and compensatory strategies aimed at counteracting the effects of low cognitive reserve, neurocognitive impairment, and psychiatric comorbidities on functional dependence in MA+/HIV+ individuals may be warranted.

Introduction. The Road Traffic Safety Strategy in the Russian Federation for 2018-2023 includes the tasks of reducing an accident rate, among which the problem of accidents outside built-up areas is highlighted. The accidents outside built-up areas are characterized with high severity of consequences. The analysis of accident factors is necessary for the development of methods to improve road safety by preventing road accidents.Determining functional dependence is necessary for the development of information road safety management systems.The article is devoted to the study of the influence of precipitation amount on the change in the risk of road accidents.Materials and methods. The study applied a relative risk analysis, which is calculated by comparing observed variables of two groups: total rainfall data (climatic frequencies) and accident sampling (frequency at time of accident).The study bases on the data of road accidents with victims and material damage that have been registered on the А-322 road (Barnaul – Rubtsovsk – the state border with the Republic of Kazakhstan) during the period from 2012 to 2017.Results. A graph functional dependence and piece wise linear functional dependency were obtained. As the result of approximation, functional dependencies in the form of third-order polynomial function were found.Practical importance. The obtained functional dependencies can be used in the management system to assess the current risk of road accidents on roads outside build-up areas. The regularity of the influence of precipitation on the risk of road accidents can be used to implement accident prevention measures at the stage of road design and operation.Originality. The study contains new results on the nonlinear form of the functional dependence of the amount of precipitation on the risk of road accidents.

BackgroundIn patients undergoing hemodialysis, functional dependence has increasingly been recognized as a critical factor influencing both quality of life and clinical outcomes. This study evaluates the combined effect of the Geriatric Nutritional Risk Index (GNRI) and Modified Creatinine Index (mCI) on predicting functional dependence in patients undergoing maintenance hemodialysis (MHD).MethodsWe conducted a cross-sectional survey at the Second Affiliated Hospital of Soochow University from June to December 2023. The study involved 208 MHD patients whose functional status was assessed using Katz and Lawton-Brod questionnaires. Patients were classified into either a normal functional group or a functional dependence group based on their scores. GNRI and mCI were categorized using cut-off values of 98.0 and 21.63 mg·kg− 1·d− 1, respectively. Logistic regression analysis was used to evaluate the risk factors and develop predictive models. The accuracy of these models was assessed through receiver operating characteristic (ROC) curves.ResultsFunctional dependence was observed in 110 patients (52.9%). The functional dependence group exhibited significantly higher age, prevalence of diabetes, and pulse pressure, but lower diastolic blood pressure, serum creatinine, serum albumin, cholesterol, GNRI, and mCI compared to the normal functional group (all P < 0.05). Logistic regression highlighted significant differences in the risk of functional dependence among the four groups based on GNRI and mCI thresholds (P < 0.05). The area under the curve (AUC) for the combined GNRI and mCI model was 0.708 (95% CI 0.638–0.778, P < 0.001), indicating superior predictive capability over the individual indices (GNRI alone AUC = 0.657, mCI alone AUC = 0.682).ConclusionGNRI and mCI, when used in combination, provide a more effective prediction of functional dependence in MHD patients than when used separately.

El síndrome confusional agudo es un problema frecuente en el adulto mayor, incrementado por patologías agudas. Objetivos: Determinar la frecuencia del síndrome confusional agudo en adultos mayores no críticos hospitalizados en un servicio de emergencia e identificar factores asociados. Diseño: Estudio transversal. Lugar: Servicio de Emergencia del Hospital Nacional Edgardo Rebagliati Martins, Lima, Perú. Participantes: Pacientes de 60 años o más. Intervenciones: Siguiendo normas de buenas prácticas clínicas, se entrevistó entre mayo y agosto 2010 a paciente/cuidador de 172 pacientes de 60 años o más, hospitalizados en salas de emergencia; se revisó la historia clínica. Principales medidas de resultados: Detectar síndrome confusional agudo mediante el Confussion Assessment Method. Resultados: La frecuencia de síndrome confusional agudo fue 34,9%, según categoría de adulto mayor: enfermo 6%, frágil 28%, complejo 58% (p&amp;lt;0,001). Se encontró antecedente de demencia en 30% de pacientes con síndrome confusional, deterioro cognitivo previo en 45%, síndrome confusional previo en 40,2%, dependencia funcional parcial 46% y total 39%, deterioro cognitivo moderado 27% y severo 40%. El 41,7% de pacientes con síndrome confusional presentó deshidratación moderadasevera (p=0,001) y 20% sepsis, como diagnósticos de ingreso (p=0,003). Las patologías de ingreso más frecuentes fueron infecciosas, cardiovasculares y metabólicas. No se encontró diferencia significativa en sexo, grado de instrucción, estado civil, pluripatología, hospitalización previa, polifarmacia, estado nutricional, presencia de sonda urinaria o nasogástrica, destino al egreso de emergencia ni estancia hospitalaria. Conclusiones: Existe alta frecuencia de síndrome confusional agudo en adultos mayores hospitalizados en servicios de emergencia, siendo factores asociados la demencia, deterioro cognitivo previo, confusión previa, dependencia funcional, categoría geriátrico complejo, deshidratación moderada-severa y sepsis.

Population aging has increased the prevalence of chronic diseases and geriatric syndromes, including functional dependence, defined as the decrease in performing Basic Activities of Daily Living (BADL). This phenomenon is associated with greater vulnerability, deterioration of quality of life and greater demand for health resources. To determine the degree of functional dependence in adults over 65 years of age treated at HGZ/MF No. 12. A descriptive, observational, and cross-sectional study was conducted in HGZ/MF No. 12 in 366 older adults aged 65 years ≥using the Barthel Index from January 2025 to December 2025. A total of 366 adults over 65 years of age were studied, of which 52.5% were female, the predominant age group was 65 to 74 years (60.4%). 54.1% had functional dependence, with a mild degree predominating (33.3%). A statistically significant association was found between age and functional dependence (p &lt; 0.001). Functional dependence is common in older adults treated at the first level of care, with mild degrees predominating. Systematic evaluation using instruments such as the Barthel Index allows patients with functional impairment to be identified in a timely manner. Keywords: functional dependence, older adults, Barthel index.

BackgroundFunctional dependence (FD) and vitamin D deficiency are common conditions in older adults. However, little is known about the relationship between FD and serum vitamin D status in centenarians. The current study was designed to evaluate the prevalence of FD and examine its relationship with serum vitamin D status among centenarians in China.Subjects and methodsA cross-sectional study of a large sample of Chinese centenarians including 180 men and 822 women was conducted from June 2014 to December 2016. Home interviews, physical examinations, and blood analyses were performed in 958 centenarians following standard procedures. FD was evaluated using the Barthel index of activities of daily living (ADL). Serum 25-hydroxyvitamin D (25OHD) concentrations were measured as a marker of vitamin D status.ResultsThe prevalence of centenarians with FD was 71.2%. Vitamin D deficiency, lack of tea consumption, lack of outdoor activities, visual impairment, and fracture were predictors of FD. Centenarians in the lowest quartile of serum 25OHD concentration had an approximately threefold greater likelihood of FD than those in the highest quartile in multiple logistic regression models (OR =2.88; 95% CI 1.75–4.73; P<0.001). The multivariable OR with a 1 ng/mL decrease in serum 25OHD concentration was 1.06 (95% CI 1.04–1.08; P<0.001) for FD.ConclusionSerum 25OHD levels have important associations with FD in Chinese centenarians. Future research could focus on the value of intervening in the case of low serum 25OHD levels through vitamin D supplementation and improving ADL in the older population.