Different Degree Of Complexity Research Articles

Computer-aided designed 3D-printed polymeric scaffolds for personalized reconstruction of maxillary and mandibular defects: a proof-of-concept study

PurposeTo investigate the potential reconstruction of complex maxillofacial defects using computer-aided design 3D-printed polymeric scaffolds by defining the production process, simulating the surgical procedure, and explore the feasibility and reproducibility of the whole algorithm.MethodsThis a preclinical study to investigate feasibility, reproducibility and efficacy of the reconstruction algorithm proposed. It encompassed 3 phases: (1) scaffold production (CAD and 3D-printing in polylactic acid); (2) surgical simulation on cadaver heads (navigation-guided osteotomies and scaffold fixation); (3) assessment of reconstruction (bone and occlusal morphological conformance, symmetry, and mechanical stress tests).ResultsSix cadaver heads were dissected. Six types of defects (3 mandibular and 3 maxillary) with different degree of complexity were tested. In all case the reconstruction algorithm could be successfully completed. Bone morphological conformance was optimal while the occlusal one was slightly higher. Mechanical stress tests were good (mean value, 318.6 and 286.4 N for maxillary and mandibular defects, respectively).ConclusionsOur reconstructive algorithm was feasible and reproducible in a preclinical setting. Functional and aesthetic outcomes were satisfactory independently of the complexity of the defect.

Методология прогнозирования и стратегии управления социальными рисками

The article deals with the problem of forecasting social risks. Before proceeding to the consideration of this issue, the author analyzes the concept of social risks, notes that there is no universal definition of social risks, identifies the main approaches to its interpretation, considers various factors contributing to the emergence of social risks and the main possible strategies for solving problems associated with the emergence of social risks. The article pays attention to the international experience of risk management. After that, the author proceeds to the consideration of the main methods of forecasting social risks, noting that the diversity of risks and factors that generate them implies the use of different methods. The diversity of methods is also due to the fact that social risks can arise at different levels of social reality, characterized by a different degree of complexity. In conclusion, the author states that the institutionalization of risk management activities indicates that modern societies are fully "risk societies".

Making movies of children's cortical electrical potentials: A practical procedure for dynamic source localization analysis with validating simulation

Dipole source localization analysis (DSLA) of brain's event-related electrical potentials (ERPs) often presumes time constraints potentially too rigid to capture complex neural dynamics. We present a practical procedure (dynamically-guided DSLA) combining in a novel way well-established off-the-shelf modeling (Independent Component Analysis, and proprietary software modules running on MATLAB, such as FASTICA and EEG-Lab DIPFIT) with the cognitive modeling simulation framework tool known as Adaptive Control of Thought-Rational (ACT-R). The integration of these multiple methods can narrow down the time-windows of interest for DSLA more flexibly. As a demonstration, we used dynamically-guided DSLA to re-analyze cluster-level ERPs from a visual target detection task involving the participation of 26 preschool children. The key analytic features were dynamic ERP movies vis-à-vis validating ACT-R simulation of comparison adult data for the same task. Spatial topography for the six estimated sources did not differ significantly in children's and adult simulated data, which generally showed high fit (predicted R2 > 0.97). A control comparison using the static DSLA showed discrepant fits for two sources, suggesting that dynamic DSLA may offer higher discriminant reliability. Given its high validity, flexibility and relative user-friendliness, dynamically-guided DSLA seems useful for assessing developmental homology and may be suitable for a variety of clinical and experimental applications specifically involving neurodevelopmental data. Statement of SignificanceAccurately determining the location of neural activity observed via electroencephalogram remains a well-known challenge. Under a variety of conditions, conventional dipole source localization analysis methodologies can result in underqualified data. In this work we present a novel process, known as dynamically-guided DSLA, which demonstrates how pre-existing tools can be appropriated to facilitate the examination and analysis of neurological activity in preschool-aged children. Because the effects exerted by a stimulus or event on EEG signals can be linked to behaviors and actions, at different levels of physical mechanisms of different degree of complexity, this neuroimaging tool offers the opportunity to cut across multiple layers of physical systems underlying cognitive and emotional functions, and therefore can be leveraged to reach invaluable insights. We highlight how the proposed technique can help link the electrophysiology to underlying physical alteration (e.g., neurodevelopmental disease); and how the proposed combination of methodologies can help "reverse engineer" physical defects or anomalies (and their locations) to quantify the EEG measurements in terms of dynamic interactive physical phenomena (movie of topographically mapped brain activity), as opposed to just giving a number against a disease or identifying a brain location.

Spatial and temporal change determined co-occurrence networks stability and community assembly processes of epipelagic seawater microbial community in the Nordic Sea

The Nordic Sea has a vital impact on the global climate change, occupies a significant status in the physical oceanography research, on account of its intersection of complex ocean currents. To explore the influence of seasonal and spatial heterogeneity in its epipelagic seawater on the microbial community structure, a total of 54 seawater samples from 18 stations and 3 water layers (0 m, 50 m, 100 m) were collected in the summer of 2017 and the autumn of 2018 from the Norwegian Sea, the Greenland Sea and the vicinity of Jan Mayen Island in the Nordic Sea. Alpha- and Beta- diversity analysis showed that significant differences were found between characteristic bacterial groups in detached or mixed currents of corresponding seasons, as endemic OTUs with seasonal and ocean current characteristics which revealed the existence of spatiotemporal patterns of microbial communities in the Nordic Sea. Moreover, co-occurrence networks were conducted to show different degree of complexity and stability of microbial community response to spatiotemporal dynamic changes. Furthermore, the flow and collision between ocean currents do have an impact on the community assembly processes by affecting the migration and dispersal of microbial communities. This study reflects the response of microbial communities to the spatiotemporal dynamics and reveals the microbial community assembly mechanisms under complex hydrological condition represented in the Nordic Sea.

Confidence and Communication Preferences on Weather Forecasts among University Students in Spain

Abstract Weather forecasts affect many persons’ lives and are used by the general public on a daily basis. However, they are not perfect, and there is an uncertainty associated with the current weather forecasts; users should be aware of this uncertainty. Previous research analyzes the perceptions, uses, and interpretations of uncertainty of Spanish undergraduate students. This study continues with this research line, but we investigate the degree of confidence and communication preferences of students enrolled in three meteorology-related subjects taught at two universities in Spain. We evaluated to what extent students trust in the current weather forecasts and analyzed how students are aware of the uncertainty associated with the forecasts considering different lead times. In addition, we assessed how students value the forecast of several weather elements as well as the students’ preferences for deterministic versus nondeterministic forecasts under two weather situations, with different degree of complexity in the forecast communication. A Google Form questionnaire was developed to address these issues. The survey was conducted in 2018/19, and 101 participants anonymously filled out the survey. Participants were enrolled in three different subjects taught in the degree in marine sciences at the University of Alicante and the degrees in environmental sciences and physics at the University of Valencia. Results show that students have a well-formed opinion of weather forecasts, both for confidence and in relation to the trend found in the current weather forecasts toward less accurate forecasts for larger lead times. For students’ preferences for deterministic versus nondeterministic forecasts, a significant majority of participants prefer weather forecasts that incorporate some uncertainty; a minority prefer single-valued (deterministic) forecasts. In comparing our results with those found in previous studies in different countries and contexts, similar outcomes are observed in general, but some differences are highlighted as well.

Demand‐oriented performance assessment using models of different degree of complexity

AbstractThis paper presents a procedure for evaluating performance objectives expressed in terms of the intended exceedance rate of a certain level of seismic demand. With the purpose of keeping the computational effort at a manageable level, the procedure relies on the use of structural models of different degree of complexity: a simplified predictor model that allows conducting hundreds of response history analyzes in a small computational time, and a sophisticated reference model able to realistically simulate overall system response. The former is used for the purposes of identifying a reduced set of ground motions for evaluating the performance objective of interest, which are then used as the input motions in the latter to estimate the level of demand with the specified exceedance rate and obtain additional insight into understanding the system in case performance needs to be improved. By introducing an intermediate structure‐specific predictor model, the so‐called demand‐oriented assessment is able to provide results that are more accurate than those obtained from intensity‐based assessments, while significantly reducing the computational effort associated to rigorous probabilistic seismic demand analysis.

Sensitivity of Chaotic Dynamics Prediction to Observation Noise

Abstract Recent advances in nonlinear time-series prediction demonstrated the ability of recurrent neural network to forecast chaotic time series on a multi-step horizon, outperforming previous approaches. Researches considered chaotic systems with different degree of complexity, but the analysis was mainly limited to the noise-free case. In this work, we extend the analysis to a noisy environment, in order to fill the gap between deterministic and real-world time series. We consider four archetypal deterministic chaotic systems each with different levels of additive noise, representing the observation uncertainty always affecting practical applications. A time series of solar irradiance is also taken into account as a real-world case study. Various neural architectures, including feed-forward and recurrent networks, are adopted as predictors. LSTM cells are used as recurrent neurons, with a special focus on the training approach. As in the noise-free case, LSTM trained without the traditional teacher forcing, i.e., with a training that replicates the forecasting conditions, proved to be the best architecture. The experiments on the archetypal systems also shows that the error due to the model identification is negligible if compared to the one caused by a small observation noise. In other words, system identification and predictions are well distinct tasks.

Different Degree of Complexity in Multiparticle Production at the LHC Energies With the Transition From Soft to Hard Processes: Hint of Possible Sources

Different Degree of Complexity in Multiparticle Production at the LHC Energies With the Transition From Soft to Hard Processes: Hint of Possible Sources

Метонимический триггер в эвфемии

The paper examines the specific role that metonymic concepts play in the semantics of euphemisms. It is shown that metonymic concepts are basic structures that underlie metaphoric concepts the meaning of euphemisms is modelled on. Such metonymic conceptual structures (metonymic triggers) constitute patterns that may generate numerous metaphoric concepts of different degree of complexity. The findings of our research testify to the fact that it is possible to single out two ways of the metonymic conceptual actualization within the framework of metaphoric concepts. In the first case gradual metaphoric complication of the metonymic concept results in the weakening of the euphemistic potential of a word or a phrase. This transformation may be accompanied by the specification of the conceptual focus though in most cases the focus is preserved. In the second case metaphoric complication of a simple metonymic concept triggers the enhancing of the euphemistic potential of a language unit. As a result, it may function in a wider range of communicative situations. The research shows that the two models are actualized differently in classical euphemy and in modern politically correct discourse. Whereas in traditional euphemistic spheres both models are common, in politically correct discourse it is the first pattern that is especially productive.

Summary of the Modern Wheel Slip Controller Principles

<span lang="EN-GB">Railway traction vehicles need to transfer high tractive effort from wheels to rails. The task is complicated because the maximum transferable force continuously changes during the train run, and the change can lead to the high wheels slip velocity or slippage. The effects are undesirable and must be prevented if it is possible or at least limited by slip controllers. There have been several slip controllers developed based on different principles with different degree of complexity and efficiency. The paper summarises principles of the slip control methods and brings their overview with the simulation of their behaviour.</span>

Form and function of negation in German and Indonesian: Searching for equivalent construction of meaning

This study analysed form and function of negation in German including the complexity of negation construction in German and its equivalence in Indonesian language. This study was qualitative in nature, describing the nature of negation in German and Indonesian language in two books: Carolin Philipps’ German novel, Traume Wohnen Überall, and Liliawati Kurnia’s translation into Indonesian, Mimpi Selalu Indah as an instance of the negation realization in texts. The validity of the data was determined by experts’ judgment and the reliability of the data by interrater and intrarater estimation. The data were analysed by using a correspondential method with a referential sorting technique involving reference to negation construction as a determiner, and a distributional method with an element distribution technique and a marker reading technique. The analysis indicates that there are six negation forms with respective meanings in German characterized by semantic similarity along with grammatical differences in the negation constructions in German and Indonesian. The findings show that German negation construction is considerably more complex. However, the different degree of complexity does not substantially influence the meaning making process in both languages; rather. tend to be mutually complementary. The findings of this study inform the way in which the meaning transfer of German-Indonesian and Indonesian-German should be made regardless of the complex negation in German.

The need for stronger commitment to laparoscopy in technically complex procedures: a differential benefit-based appraisal

Background: The aim of the present study is to evaluate the differential benefit of laparoscopic over open technique according to the technical difficulty of the procedures and to define - according to this parameter - the strength of commitment to minimally invasive approach. Material and Methods: 936 MILS resections performed between 2005 and 2018 were stratified according to technical complexity (Low, Intermediate and High difficulty) and to approach (MILS or open) and then matched in a 1:1 ratio using propensity scores to obtain three pairs of groups (Pair 1:Low-MILS and Low-Open, including 274 cases respectively; Pair 2: Int-MILS and Int-Open, including 237 patients respectively; Pair 3: High-MILS and High-Open, including 226 patients respectively). Blood loss, postoperative morbidity and time for functional recovery were chosen as outcome indicators to calculate the differential benefit among pairs. Results: Within pairs, preoperative characteristics of patients and disease were comparable between MILS and open approach. MILS approach resulted in a statistically significant lower blood loss, reduced morbidity, reduced and shorter time for functional recover and length of stay within all pairs. Reflecting different degree of complexity, procedures showed significantly different blood loss, morbidity, rate of conversion and time for functional recovery among different Pairs. The evaluation of the differential benefit showed a greater advantage of laparoscopic approach in High degree procedures compared with Intermediate and Low degree, both in terms of blood loss (-250 mL and -200 mL respectively) and morbidity rate (-5.7% and -4.1% respectively). Conclusion: The favorable biological scenario associated with laparoscopic approach allows to obtain significant benefits in the setting of technically complex procedures, constituting the prerequisite for an adequate surgical outcome. The commitment towards MILS approach should be therefore stronger in this setting, where - overcome the limit of technical challenges - the advantage of laparoscopy seems to be enhanced.

A stepwise learning curve to define the standard for technical improvement in laparoscopic liver resections: complexity-based analysis in 1032 procedures.

The objective of this study is to define the learning curve in a series of procedures grouped according to their complexity calculated by difficulty index to define a standard for technical improvement. 1032 laparoscopic liver resections performed in a single tertiary referral center were stratified by difficulty scores: low difficulty (LD, n = 362); intermediate difficulty (ID, n = 332), and high difficulty (HD, n = 338). The learning curve effect was analyzed using the cumulative sum (CUSUM) method taking into consideration the expected risk of conversion. The ratio of laparoscopic/total liver resections increased from 5.8% (2005) to 71.1% (2018). The CUSUM analysis per group showed that the average value of the conversion rate was reached at the 60th case in the LD Group and at the 15th in the ID and HD groups. The evolution from LD to ID and HD procedures occurred only when learning curve in LD resections was concluded. Reflecting different degree of complexity, procedures showed significantly different blood loss, morbidity, and conversions among groups. A standard educational model-stepwise and progressive-is mandatory to allow surgeons to define the technical and technological backgrounds to deal with a specific degree of difficulty, providing a help in the definition of indications to laparoscopic approach in each phase of training.

Response spectrum analysis of frame structures: reliability-based comparison between complete quadratic combination and damping-adjusted combination

In the framework of seismic design of structures, response spectrum analysis (RSA) is the most commonly used approach in practice. The most popular combination rule is the complete quadratic combination (CQC) which is also prescribed by the most of seismic design codes and is based on the assumptions that the seismic acceleration is a white noise process and the peak factor ratios associated to the total and modal responses are unitary. Recently, the damping adjusted combination (DAC) rule has been developed for base-isolated structures to overcome the aforementioned simplified assumptions. Although it has been proved that the simplifications about peak factors lead to noticeable errors in the case of base-isolated structures, the accuracy gain of DAC with respect to CQC in the case of fixed-base structures is still unknown. Therefore, the paper presents an in-depth study on the RSA of three-dimensional frame structures, aimed to evaluate the accuracy of the above methods. Two reference classes of frame structures having different degree of complexity are considered. Average interstorey drift and floor torsion responses, obtained from a set of Time History Analyses are compared with those of the modal combination rules. Lognormal joint probability density functions of the predictive errors from CQC and DAC are finally evaluated for a reliability assessment of the two combination rules under bidirectional seismic excitations.

Modeling of Rayleigh-Taylor mixing using single-fluid models.

Turbulence mixing models of different degree of complexity are investigated for Rayleigh-Taylor mixing flows with reference to high-resolution implicit large eddy simulations. The models considered, in order of increasing complexity, comprise the (i) two-equation K-L, (ii) three-equation K-L-a, (iii) four-equation K-L-a-b, and (iv) Besnard-Harlow-Rauenzahn (BHR-2). The above models are implemented in the same numerical framework to minimize the computational uncertainty. The impact of the various approximations represented by the different models is investigated for canonical one-dimensional (1D) Rayleigh-Taylor mixing and for the more complex (2D on average) case of the tilted-rig experiment, aiming to understand the balance between accuracy and complexity. The results provide guidance on the relative merits of various turbulence models over a variety of conditions.

Вычислительные алгоритмы моделирования одномерных обводов через k наперед заданных точек

In this paper have been proposed theoretical bases for formation one-dimensional contours of the first order smoothness, passing through k in advance given points, including requirements to the contour in general, and the contour’s arcs in particular, as well as representations for tangents in extreme and intermediate contour sections, which determine the contour arc shape. Based on this theoretical material have been developed computational algorithms for simulation of closed (A5, A6) and open (A1-A4) contours according to postulated conditions, which allow form irregular composite curves and surfaces with different degree of complexity, docked together on the first order smoothness. The proposed computational algorithms can also be used to construct contours of higher orders smoothness using arcs of the same ratio curves. For analytical description of computational algorithms for one-dimensional contours simulation is used the mathematical apparatus of BN-calculation (Balyuba – Naidysh point calculation). The obtained algorithms have been presented in a point form, which is a symbolic form. For transition from point equations to a system of parametric equations, it is necessary to perform a coordinate-by-coordinate calculation, which can be presented geometrically as population of projections on the global coordinate system’s axes. As an example has been presented a computational algorithm that provides the use a system of parametric equations instead of symbolic point recording. The proposed algorithms have been successfully used for computer modeling and prediction for the impact of geometric shape imperfections on the strength and stability of engineering structures’ thin-walled shells. In particular, a numerical study method for a stress-strain state of steel vertical cylindrical reservoirs with regard to imperfections of theirs geometric shapes has been proposed.

Estimating Junior School-Age Children’s Mastery of Complex Movements Applying Parametric Teaching

After realizing the fact that learning new movements and actions is efficient only in the case when the child is capable of applying the movement or action learnt under new conditions, when the skill acquired is remembered and retained for long the authors (Schmidt, 1988, 1991; Schmidt, Lee, 1999; Skurvydas, 1998; Skurvydas, Gedvilas, 2000) have singled out and defined the parametric teaching of movements. Therefore the following research problem arises: is the parametric method of teaching effective in teaching children of junior school-age to perform complex movements and actions, as well as to retain them for long and apply them under new conditions. The aim of the research was to establish and estimate the efficiency of the parametric method and mastery in teaching children of the junior school age the accuracy of movements, retaining power and creativity of the complex movements learnt. With a view to find out the efficiency of parametric teaching a pedagogical experiment with junior schoolchildren (n = 67) aged 8—10 years was carried out. During all teaching stages the program of the movements taught was applied in the period of 7—8 weeks. In this period the observation of the development of mastering new movements in the standard teaching group and in that of parametric teaching took place. During the following 2 months the efficiency of standard and parametric teaching applied was observed, i. e. the ability to retain the movements learnt for as long as possible. We can conclude that the more relatively complicated movements and actions are taught the less difference between efficiency of standard teaching and parametric teaching is found: when teaching complicated accuracy requiring movements using both standard and parametric methods, development and level of mastering are adequate; when teaching complicated locomotive movements, the children of standard teaching group master the movements more rapidly; when teaching complicated high accuracy requiring combinations of locomotive movements under standard and variable conditions, the indices of development of mastering did not differ essentially. The children of standard and parametric teaching groups retained and reproduced (after 1 and 2 months) complicated movements of different degree of complexity in a different way: the children who had been taught under variable conditions markedly better retained and reproduced both complicated locomotive and complicated locomotive movements requiring accuracy; the children of parametric teaching groups who had been taught the same movements and their combinations under conditions of change in parameters of high degree, better retained and reproduced the movements than the children of other parametric teaching groups. The efficiency of standard and parametric teaching of complicated movements for children’s abilities to retain them for a longer period of time, reproduce and apply them in new circumstances — creativity of movements — depends on the character of the circumstances changed: the children of parametric teaching groups in new circumstances by a long way better retained and reproduced movements previously learnt which were complicated locomotive ones when structure of a movement was altering and necessity to make a choice existed.Keywords: parametric teaching, teaching children under standard and variable conditions, junior school-age (8—10 years).

A complexity-based and stepwise learning curve in 607 laparoscopic liver resections: a single surgeon analysis to define a standard for technical improvement

Importance: The standard educational path to complete the learning curve in laparoscopic liver resections (LLR) should be defined taking into account the degree of surgical complexity, to maintain an adequate profile of safety until its completion. Objective: To define a single surgeon learning curve in a series of procedures grouped according to their complexity calculated by difficulty index to define a standard for technical improvement. Design: 607 LLR performed by a single surgeon (2005-2017) were stratified by difficulty scores: Low-Difficulty (LD, n=227); Intermediate-Difficulty (ID, n=197) and High-Difficulty (HD, n=183). The learning curve effect was analyzed in the three Groups using the Cumulative Sum (CUSUM) method taking into consideration the expected risk of conversion. Results: Along with increasing numerosity and complexity of cases, the ratio laparoscopic/total liver resections increased from 5.8% (2005) to 72.8% (2017). The CUSUM analysis per group showed that the average value of the conversion rate was reached at the 50th case in the LD Group and at the 15th in the ID and HD groups. The evolution from LD to ID and HD procedures occurred only when learning curve in LD resections was concluded. Reflecting different degree of complexity, procedures showed significantly different blood loss, morbidity and conversions among groups. Conclusion: A standard educational model - stepwise and progressive - is mandatory to allow surgeons to define the technical and technological background to deal with a specific degree of difficulty, providing an help in the definition of indications to laparoscopic approach in each phase of training.

Bigleaf-An R package for the calculation of physical and physiological ecosystem properties from eddy covariance data.

We present the R package bigleaf (version 0.6.5), an open source toolset for the derivation of meteorological, aerodynamic, and physiological ecosystem properties from eddy covariance (EC) flux observations and concurrent meteorological measurements. A ‘big-leaf’ framework, in which vegetation is represented as a single, uniform layer, is employed to infer bulk ecosystem characteristics top-down from the measured fluxes. Central to the package is the calculation of a bulk surface/canopy conductance (Gs/Gc) and a bulk aerodynamic conductance (Ga), with the latter including formulations for the turbulent and canopy boundary layer components. The derivation of physical land surface characteristics such as surface roughness parameters, wind profile, aerodynamic and radiometric surface temperature, surface vapor pressure deficit (VPD), potential evapotranspiration (ET), imposed and equilibrium ET, as well as vegetation-atmosphere decoupling coefficients, is described. The package further provides calculation routines for physiological ecosytem properties (stomatal slope parameters, stomatal sensitivity to VPD, bulk intercellular CO2 concentration, canopy photosynthetic capacity), energy balance characteristics (closure, biochemical energy), ancillary meteorological variables (psychrometric constant, saturation vapor pressure, air density, etc.), customary unit interconversions and data filtering. The target variables can be calculated with a different degree of complexity, depending on the amount of available site-specific information. The utilities of the package are demonstrated for three single-level (above-canopy) eddy covariance sites representing a temperate grassland, a temperate needle-leaf forest, and a Mediterranean evergreen broadleaf forest. The routines are further tested for a two-level EC site (tree and grass layer) located in a Mediterranean oak savanna. The limitations and the ecophysiological interpretation of the derived ecosystem properties are discussed and practical guidelines are given. The package provides the basis for a consistent, physically sound, and reproducible characterization of biometeorological conditions and ecosystem physiology, and is applicable to EC sites across vegetation types and climatic conditions with minimal ancillary data requirements.

Chaos based nonlinear analysis to study cardiovascular responses to changes in posture

Cardiovascular responses to changes in posture have been the focus of numerous investigations in the past. Analysis of ECG and arterial blood pressure (ABP) data for different postures, obtained from ‘Physionet’ was done from a new perspective of analyzing nonlinear time series having multifractal features. Multifractal detrended fluctuation analysis (MFDFA) and also the cross-correlation between ECG and BP with another technique Multifractal detrended cross-correlation analysis (MFDXA) reveals ECG and ABP time series of different subjects to be multifractal in nature with different degree of complexity. Different degree of auto and cross-correlation for both ECG and ABP signals is also observed for all subjects.Further significant information obtained from the cross-correlation parameters obtained from MFDXA analysis is very important and relevant particularly for understanding the dynamics of orthostatic stress.