Multilevel Modeling Strategy Research Articles

Dynamic testing and modeling of span interaction in high-speed railway girder bridges

This paper presents the results of an extensive experimental campaign conducted on high-speed railway girder bridges along the Rome-Florence railway line. The campaign includes material characterization and in-situ dynamic tests, incorporating vibration signals from both ambient-induced activities and train passages. The study focuses on the modeling and simulation procedures necessary for analyzing existing railway girder bridges, considering the dynamic interaction between adjacent simple supported spans. The degree of coupling caused by railroad equipment can lead to interaction phenomena, such as vibrations corresponding to mode shapes encompassing multiple spans, observed along the bridge. A multilevel modeling strategy is proposed, starting with a single span to identify the most accurate and computationally efficient approaches (frame-based, shell-based, or mixed). Subsequently, full-scale and reduced-order models of the entire structures are developed, considering the connections between rails, superstructure, and piers, to study the interaction between adjacent spans. Three case studies are presented to demonstrate the general validity of the proposed approaches, comparing the numerical results with experimental outcomes obtained from the in-situ tests.

Spatio-Temporal Distribution of Colorectal Cancer Incidence in Córdoba, Argentina.

To study the trend of colorectal cancer (CRC) incidence, considering its spatiotemporal distribution and its association with the level of urbanisation in Córdoba, Argentina (2004-2014). An ecological and longitudinal study was conducted in the province of Córdoba (the second most populated of the country) using annual data for the period 2004-2014. Age-standardised incidence rates (ASIR) (standard national and world population) by sex were calculated for Córdoba and its 26 departments for CRC using the provincial tumour registry database. Joinpoint regression models were adjusted to provincial ASIRs. Departments ASIRs were mapped in quintiles. The departments were grouped into three strata according to urbanisation: High (n1=6, >107,000 people); Intermediate (n2=13, 33,000-107,000 people); and Low (n3=7, <33,000 people). The spatio-temporal correlation analysis of the departments' rates was fulfilled using the multilevel modelling strategy. ASIRs of CRC in Córdoba province were 30.9 ±1.5 and 24.3 ±1.5 cases/100,000 for men and women, respectively. During 2004-2014, ASIRs tended to decrease (annual per cent change: -0.6; CI95% -1.8, 0.6). Maps reflected different geospatial patterns by sex. CRC incidence in males was higher than in females in all strata (high urbanisation, incidence rate ratios (IRR): 1.66; intermediate, IRR: 1.59; and low, IRR: 1.40). There was a significant downward temporary variation in the most populous departments (3% per year). CRC presents a non-random spatial pattern across the territory with a decreasing temporal variation in the most populous departments. Differential incidence and temporospatial tendency burden in Córdoba involve sex and urbanisation. Men continue to be the population at the greatest risk; this pattern is more noticeable in most urban settings.

Quantifying the groundwater total contamination risk using an inclusive multi-level modelling strategy

This paper investigates aggregated risks in aquifers, where risk exposures may originate from different contaminants e.g. nitrate-N (NO3–N), arsenic (As), boron (B), fluoride (F), and aluminium (Al). The main goal is to develop a new concept for the total risk problem under sparse data as an efficient planning tool for management through the following methodology: (i) mapping aquifer vulnerability by DRASTIC and SPECTR frameworks; (ii) mapping risk indices to anthropogenic and geogenic contaminants by unsupervised methods; (iii) improving the anthropogenic and geogenic risks by a multi-level modelling strategy at three levels: Level 1 includes Artificial Neural Networks (ANN) and Support Vector Machines (SVM) models, Level 2 combines the outputs of Level 1 by unsupervised Entropy Model Averaging (EMA), and Level 3 integrates the risk maps of various contaminants (nitrate-N, arsenic, boron, fluoride, and aluminium) modelled at Level 2. The methodology offers new data layers to transform vulnerability indices into risk indices and thereby integrates risks by a heuristic scheme but without any learning as no measured values are available for the integrated risk. The results reveal that the risk indexing methodology is fit-for-purpose. According to the integrated risk map, there are hotspots at the study area and exposed to a number of contaminants (nitrate-N, arsenic, boron, fluoride, and aluminium).

Quantifying the Groundwater Total Contamination Risk Using a Multi-Level Modelling Strategy

Quantifying the Groundwater Total Contamination Risk Using a Multi-Level Modelling Strategy

The volume and outcome relationship for thyroidectomy in England.

PurposeThe delivery of surgical care in England has seen a momentum towards centralisation within larger volume hospitals and surgical teams. The aim of this study was to investigate outcomes in England in relationship to hospital and surgeon annual volumes for total thyroidectomy.MethodsData were extracted from the Hospital Episodes Statistics (HES) database for England. A 6-year period (April 2012–March 2018 inclusive) for all adult admissions for thyroidectomy was used in the analysis. The primary outcome measure used was a length of hospital stay greater than 2 days or an emergency readmission within 30 days following surgery. This was used as a proxy for surgical complications. A multilevel modelling strategy was used to adjust for hierarchy and potentially confounding.ResultsData for 22,823 total thyroidectomies across 144 hospital trusts were used for analysis. For total thyroidectomy, larger volume surgeons had reduced levels of post-surgical complications; length of stay > 2 and > 4 days; emergency readmission at 30 days; and hypoparathyroidism, vocal cord palsy, stridor, and tracheostomy at 1-year post-surgery. Larger hospital volume was associated with lower levels of emergency readmission at 30 days and hypoparathyroidism at 1 year.ConclusionsThere is significant correlation between surgeon volume and clinical outcome for total thyroidectomy. The relationship was approximately linear, and a low-volume threshold could not be defined.Supplementary InformationThe online version contains supplementary material available at 10.1007/s00423-021-02223-8.

Alexithymia explains atypical spatiotemporal dynamics of eye gaze in autism

Recognition of emotional facial expressions is considered to be atypical in autism. This difficulty is thought to be due to the way that facial expressions are visually explored. Evidence for atypical visual exploration of emotional faces in autism is, however, equivocal. We propose that, where observed, atypical visual exploration of emotional facial expressions is due to alexithymia, a distinct but frequently co-occurring condition. In this eye-tracking study we tested the alexithymia hypothesis using a number of recent methodological advances to study eye gaze during several emotion processing tasks (emotion recognition, intensity judgements, free gaze), in 25 adults with, and 45 without, autism. A multilevel polynomial modelling strategy was used to describe the spatiotemporal dynamics of eye gaze to emotional facial expressions. Converging evidence from traditional and novel analysis methods revealed that atypical gaze to the eyes is best predicted by alexithymia in both autistic and non-autistic individuals. Information theoretic analyses also revealed differential effects of task on gaze patterns as a function of alexithymia, but not autism. These findings highlight factors underlying atypical emotion processing in autistic individuals, with wide-ranging implications for emotion research.

Role of informal institutions in the relationship between social capital and international entrepreneurial entry

Purpose. The goal of the current study is to gain an understanding of how various informal institutional elements such as trust and corruption control affect the relationship between entrepreneurial ventures’ social capital and their ability to reach the worldwide market. Design/Methodology/Approach. The paper draws on internationalization and social capital data from the Global Entrepreneurship Monitor (GEM), which includes 482,257 observations from 44 countries between 2003-2013, with a focus on early-stage entrepreneurs (as defined by the TEA index) who are involved in significant international entrepreneurial entry. A multi-level modelling strategy is employed for analyzing the various hypotheses by using STATA. Findings. Possessing a high level of social capital makes it easier to start a business at the international stage. And further, informal institutional variables, i.e., trust and control of corruption, positively moderate the association between social capital and international entrepreneurial entry; thus, societies where honesty prevails and corruption is controlled facilitate better international entrepreneurial entry. Limitations/Implications. The study is based on informal institutions, i.e., the variable trust taken from the World Value Survey (WVS) and the variable control of corruption by using a large sample size and multi-level modelling from World Governance Indicators, which demonstrates the importance of institutions as systems of shared meanings and noncodified standards. However, there are a number of other informal institutional indicators to examine that could have an impact on the relationship at the individual level. Implications from a theoretical perspective explain advancement of the institutional perspective as a conceptual framework for explaining international entrepreneurial activity and, further, the study empirically validates the significance of informal institutional environmental factors in the context of international entrepreneurship. Originality/Value. With the increasing interest of scholars in using the institutional approach and the availability of limited empirical studies in light of informal institutions, using a multi-level approach the current study empirically investigates the role of trust and control of corruption in the context of social capital and international entrepreneurship. Keywords: social capital, internationalization, international entrepreneurship, informal institutions

Multi-Hazard Assessment of Bridges in Case of Hazard Chain: State of Play and Application to Vehicle-Pier Collision Followed by Fire

This study focuses on multi-hazard analysis for bridges, following a two-tier approach. First, it identifies relevant open issues and recent literature developments in the field, presenting data in a meaningful manner, with specific focus on the issues related with the analysis of hazard chain scenario treated as low probability-high consequence events. Second, it describes a practically useful and sufficiently generic approach for efficient computational investigation of hazard-chain scenarios in highway bridges. Following that, the applicability of the approach is exemplified in an appealing and commonly encountered in real-life hazard-chain scenario, in which a multilevel modeling strategy is adopted to assess the structural response under hazard chain scenarios of a highway viaduct. Among the considered scenarios is the impact of a heavy vehicle (tank truck) on the bridge pier, and the fire spread following the collision due to the presence of inflammable material. The bridge structure is a typical 189m long multi-span composite highway viaduct. The impact is modelled with a non-linear transient dynamic analysis that accounts the inertial effect of the global structure, while the fire modelling is performed with non-linear quasi static dynamic analysis focusing on local behavior with a sub-structured model. Then different impact and fire scenarios are considered, including different impact velocities of the truck.

Trends in Pain Prevalence among Adults Aged 50 and Older across Europe, 2004 to 2015.

Objectives: We examine recent trends in pain prevalence among adults aged 50+ across Europe. Methods: Data for 15 countries from the Survey of Health, Ageing, and Retirement in Europe are examined for two periods: 2004-2011 and 2013-2015. Trends are shown descriptively, using a multilevel modeling strategy controlling for covariates, and modeled on a country-specific basis. Results: Population-level pain prevalence ranges from about 30% to about 60% depending on the country and year. Pain is more prevalent in women and generally increases with age. There is an increase in prevalence over time, net of age, and other predictors. Prevalence increased with an annual average of 2.2% between 2004 and 2011 and 5.8% between 2013 and 2015, in fully adjusted models. Discussion: Trends in pain prevalence have implications for disability, healthcare utilization, productivity, and population health. These findings are not optimistic but align with other population-wide studies, suggesting a global trend of rising pain prevalence.

State variation in the drug felony lifetime ban on Temporary Assistance for Needy Families: Why the modified ban matters

The drug felony lifetime ban on Temporary Assistance for Needy Families (TANF) affects thousands of individuals with felony drug convictions in the United States. Federal law allows states to choose to opt out or modify the full ban. Prior research has treated the ban as a binary outcome, characterizing anything but a full ban as a sign of state reform of this harsh collateral consequence. We argue that modified versions of the ban, which simultaneously allow greater access to public aid while also monitoring and sanctioning recipient behavior, have been overlooked but pose important theoretical and empirical challenges to this narrative. To address this gap, we analyze state discretion in the implementation of the drug felony lifetime ban on TANF receipt between 1997 and 2010 utilizing a multilevel multinomial modeling strategy. Results reveal that distinct patterns of state-level factors are associated with each form of the ban, highlighting the need to treat modified bans as unique policy choices in their own right. Our study informs the understanding of state implementation of collateral consequences that straddle both the penal and welfare systems in the United States.

MultiLevel Modeling of Space–Time Variations: Exploring Landslide Voting Patterns at United States Presidential Elections, 1992–2016

Much has been written about the polarization of the American electorate and its reflection in its legislatures, but less about its spatial polarization, which Bishop has argued has taken place in parallel with the ideological and behavioral polarization. The extent of that polarization can be assessed, he argues, by identifying the number of landslide counties, those won at presidential elections by margins of 20 percentage points or more. This paper uses a multilevel modeling strategy to explore changes in the number and extent of those landslide counties over the period 1992–2016, relative to both the location of the counties and their population composition. It shows that a county’s population composition was a major determinant of whether it returned a landslide for either party’s candidate at any election—with a clear change in direction over the period for counties according to their level of affluence—but this was by no means the sole determinant. Holding constant those variations there were additional geographies that were more place‐ than people‐specific.

Reconceptualizing Context: A Multilevel Model of the Context of Reception and Second‐Generation Educational Attainment

This paper seeks to return scholarly attention to a core intellectual divide between segmented and conventional (or neo‐)assimilation approaches, doing so through a theoretical and empirical reconsideration of contextual effects on second‐generation outcomes. We evaluate multiple approaches to measuring receiving country contextual effects and measuring their impact on the educational attainment of the children of immigrants. We demonstrate that our proposed measures better predict second‐generation educational attainment than prevailing approaches, enabling a multilevel modeling strategy that accounts for the structure of immigrant families nested within different receiving contexts.

Maximum energy conversion from human motion using piezoelectric flex transducer: A multi-level surrogate modeling strategy

Conventional engineering design optimization requires a large amount of expensive experimental tests from prototypes or computer simulations, which may result in an inefficient and unaffordable design process. In order to overcome these disadvantages, a surrogate model may be used to replace the prototype tests. To construct a surrogate model of sufficient accuracy from limited number of tests/simulations, a multi-level surrogate modeling strategy is introduced in this article. First, a chosen number of points determined by optimal Latin Hypercube Design of Experiments are used to generate global-level surrogate models with genetic programming and the fitness landscape can be explored by genetic algorithms for near-optimal solutions. Local-level surrogate models are constructed then from the extended-optimal Latin Hypercube samples in the vicinity of global optimum on the basis of a much smaller number of chosen points. As a result, an improved optimal design is achieved. The efficiency of this strategy is demonstrated by the parametric optimization design of a piezoelectric flex transducer energy harvester. The optimal design is verified by finite element simulations and the results show that the proposed multi-level surrogate modeling strategy has the advantages of faster convergence and more efficiency in comparison with the conventional single-single level surrogate modeling technique.

Property Rights Regimes, Technological Innovation, and Foreign Direct Investment

We argue that democratic institutions influence property rights in attracting foreign direct investment (FDI) by providing: (1) a coherent logic to the property rights regime that is created in a state and (2) a legitimate way to manage conflicts that arise in dynamic economies. We expect that the marginal effect of property rights in attracting FDI has increased over time with the rate of technological dynamism. We test this using a non-nested multilevel modeling strategy with random coefficients on data from 1970 to 2009. Our results demonstrate that the effect of property rights on attracting FDI is contingent on democratic institutions and that this effect becomes more pronounced over time. This effect holds for both developing and developed countries across all regions.

Mindfulness-based Intervention in Elementary School Students With Anxiety and Depression: A Series of n-of-1 Trials on Effects and Feasibility.

Mindfulness-based interventions constitute a promising option to address anxiety and depression in elementary school students. This study evaluated the effect of a mindfulness-based intervention on anxiety and depression in elementary school students with a diagnosis of anxiety or depression disorder. A single-subject experimental A-B-A design was used. Participants were three elementary school students from grades three and four, along with their teacher. Anxiety and depression were measured on 10 occasions at baseline, during the intervention, and at follow-up. Primary hypotheses were tested using a univariate single case multilevel modeling strategy and visual analysis. Following intervention, 2 participants reported improvements on anxiety and depression, while their teachers reported deteriorating scores on these variables. Results from this n-of-1 trial design is consistent with other work suggesting caution with regard to the overall impact and efficacy of mindfulness-based interventions as a universal treatment option for youth. Future research is warranted.

Environmental stressors, socioeconomic factors, and alcohol-related problems among Argentinian college students

Introduction. The relationship between alcohol consumption, individual characteristics, and alcohol-related problems may vary according to environmental characteristics in certain populations. Objective. To explore the existence of a hierarchical structure in the links between environmental stressors, individual socioeconomic factors, regular alcohol consumption, use of other substances, and alcohol-related problems in Argentinian university students. Method. With a correlational design and data from a random sample of students from a public university (N = 1578, 58% female), we used a multilevel modeling strategy as follows: alcohol-related problems; regular alcohol consumption (quantity/frequency) as fixed effect, use of other psychoactive substances, sociodemographic factors (individual socioeconomic status, age, and gender); and environmental stressors as random effects (index of overcrowding as an indicator of poverty and reported crime as an indicator of violence in the neighborhood). Results. The rate of overcrowding proved to be the best Level 2 predictor for the alcohol-related problems model. Socioeconomic status, quantity and frequency of consumption, use of other substances, and age directly predicted alcohol-related problems (Level 1). Gender was neither a direct predictor nor a moderator of the links. Discussion and conclusion. At least one environmental stressor (neighborhood poverty) partly explains the variability observed in alcohol-related problems. The quantity and frequency of alcohol consumption and the use of other psychoactive substances were the strongest predictors of alcohol-related problems.

Robust methodology of automatic design for automobile panel drawing die based on multilevel modeling strategy

The automation and robustness have always been the focal points in the design system for stamping die. A robust methodology of automatic design based on multilevel modeling strategy is presented in this paper for automobile panel drawing die by analyzing and eliminating the factors that lead to design failure. The inherent attribute of geometry is blamed for the failure, which is defined as “ambiguous modeling failure (AMF) caused by orientation attribute.” The methodology is aimed at guaranteeing the remodel robustness and improving the automation level of die design, which is discussed under three aspects: structure modeling, die checking, and parameter managing. (1) The multilevel modeling strategy is designed to guarantee the robustness of structure modeling through treating AMFs in advance, intensively and hierarchically by redefining the modeling procedure and building two control units. (2) Automatic check of die structure is expected to drastically promote design efficiency, which will ensure checking correctness and reduce checking cost compared with manual work. (3) The well-managed parameters facilitate the invocation of parameters for the users, which make the die alterations more convenient and faster. Finally, an automated design system for automobile panel drawing die is developed on top of CATIA V5 to verify the methodology, which can accomplish the main structures, layout of standard parts, and check of die structure automatically. Experimental results and feedback from the design office together indicate that the system can improve design efficiency and design quality dramatically.

Democracy and child health in developing countries

The rise of democracy across the world brought with it expectations that governments would be more attentive and responsive to the welfare of the people, creating better services and better health. Indeed, a considerable body of scholarship finds that democracy has significant, direct effects on multiple measures of well-being, particularly life expectancy and infant mortality. Despite several recent critiques, the paramount theme is that democracy is good for health. This study contributes to this literature by assessing the relationship between democracy and child diarrhea and malnutrition across 52 developing countries. Using a multilevel modeling strategy, the analysis examines the country-level effects of democracy and development on child health, while simultaneously taking into account wealth, education, and other household characteristics at the individual level. Contrary to much previous scholarship, democracy does not exhibit a significant association with diarrhea or malnutrition. Instead, gross domestic product (GDP) per capita and improved sanitation and water have substantial effects on child health at the country level. At the individual level, household wealth and maternal education have the largest health-enhancing impact on child diarrhea and malnutrition. Furthermore, the size and strength of the relationship between wealth and health does not vary by political regime. These results demonstrate the enduring importance of socioeconomic status regardless of political context, and they support a small but growing literature that calls the democracy–health link into question.

The impact of performance funding on institutional performance over time: evidence from South Korean universities

Performance funding for higher education has gained popularity in many countries, but its impact on institutional performance remains unclear. This study investigates the impact of performance funding on the institutional performance of Korean universities over time. The institutional performance indicators used include graduates’ employment rate, student retention rate, financial aid per student, expenditure per student, and faculty-to-student ratio. Using longitudinal data of 160 4-year universities from 2008 to 2013, we employed a multilevel growth modeling strategy. The results indicate that institutions with more funding through the Education Capacity Enhancement Program sustained higher employment rate, retention rate, and faculty-to-student ratio in 2013, while employment and retention rates of less-funded institutions grew faster over time after controlling for 2008 status and institutional characteristics. This evidence demonstrates that the performance funding program in Korea encouraged institutions to focus on the most important performance indicators, resulting in a funding effect and a motivational effect. We suggest policy implications for the future development of performance funding as well as appropriate use of performance indicators.

Does regulation make political parties more popular? A multi-level analysis of party support in Europe

This article examines the relationship between party regulation, trust in political parties and partisanship in 24 European democracies in 2010. It tests two rival hypotheses, one suggesting that the regulation of political parties improves party support among electorates, and the other arguing the opposite case that regulation weakens support for parties. These hypotheses are tested using a multi-level modelling strategy that controls for a number of variables that might account for trust in parties and partisanship at the individual level. The evidence suggests that heavy regulation of political parties is associated with low levels of trust in parties and fewer partisans in these countries. This finding persists even in the presence of a variety of control variables. The analysis uses cross-sectional data and so definitive causal relationships cannot be fully identified, but the data implies that regulation by the state in the context of a severe economic recession could be having the effect of stifling support for political parties and weakening civil society.