Principal Assumption Research Articles

How do babies come to know what babies know?

Elizabeth Spelke's What Babies Know is a scholarly presentation of core knowledge theory and a masterful compendium of empirical evidence that supports it. Unfortunately, Spelke's principal theoretical assumption is that core knowledge is simply the innate product of cognitive evolution. As such, her theory fails to explicate the developmental mechanisms underlying the emergence of the cognitive systems on which that knowledge depends.

Insight into the dynamics of bioconvective Walter’s-B nanofluid flow subjected to Cattaneo–Christov heat flux and activation energy

In order to study the implementation of the generalized magnetohydrodynamic (MHD) bioconvective aspects of the Walter’s-B fluid flows over a convectively heated stretched sheet in the presence of activation energy and numerous boundary conditions, the non-homogeneous nanofluid flow model is used. Here, the nonlinear differential equations illustrating the current nanofluid flow model of non-Newtonian fluid explicitly include the concentration of both motile microbes and solid nanoparticles. Furthermore, the associated temperature, impact of thermal radiation and the Cattaneo–Christov heat flux model are discussed. The similarity transformations are formally displayed to transfer the consequential reduction in the mathematical complexity of the existing physical situation by converting partial differential equations (PDEs) into a nonlinear associated framework of ordinary differential equations (ODEs). Furthermore, the homotopy analysis method (HAM) through the MATLAB tool is used to numerically solve the dimensionless similarity equations. The results are extremely well demonstrated. In this manner, the significant engineering procedures are more accurately and entirely estimated before being reported. The results of the fixed physical factors of velocity, temperature, concentration, and microbe concentration profiles are effectively demonstrated through multiple types of illustrations and comprehensive explanations. The principal assumption is that the greater significance of the bioconvection Lewis and Peclet numbers can lead to a drop in the microbe concentration profile. It is observed that the concentration profile is reduced with the greater value of the concentration relaxation parameter.

On alternative strain rate analysis for direct impact method

The direct impact method provides a higher sample deformation rate in comparison with the classical Split Hopkinson Pressure Bar method. The principal assumption of strain rate calculation for the direct impact method is constancy of velocity of the impacted face of the specimen during the impact. This assumption delivers reliable results for materials with relatively low yield strength and hardening rate. The present study proposes an alternative procedure for calculation of the specimen strain rate in order to improve accuracy of the direct impact method for wide range of metals and alloys. The proposed procedure is based on the assumption that the transmitted pulse can be splitted into parts, one of which corresponds to stress and the other to strain rate. The procedure has been validated by finite element analysis and the semi-analytical modelling of the direct impact tests of pure copper C101 and additively manufactured Inconel 718 alloy. The proposed method qualitatively changes the shape of the stress-strain curve by adding an unloading area. The numerically estimated accuracy of the method is limited by 4.5% for Inconel 718 and 0.6% for copper C101. The proposed alternative analysis of the strain rate for a direct impact has a number of advantages over the classical methods and can be used in the study of various materials in a wide range of strain rate.

The effectiveness of weighted least squares means and variance adjusted based fit indices in assessing local dependence of the rasch model: Comparison with principal component analysis of residuals.

Local independence is a principal assumption of applying latent variable models. Violations of this assumption might be stemmed from dimensionality (trait dependence) and statistical independence of item responses (response dependence). The purpose of this study is to evaluate the sensitivity of weighted least squares means and variance adjusted (WLSMV) based global fit indices to violations of local independence in Rasch models, and compare those indices to principal component analysis of residuals (PCAR) that is widely used for Rasch models. Dichotomous Rasch model is considered in this simulation study. The results show that WLSMV-based fit indices could detect trait dependence, but are to be limited with regard to response dependence. Additionally, WLSMV-based fit indices have advantages over the use of PCAR since WLSMV-based global fit indices are consistent regardless of sample size and test length. Though it is not recommended to apply exact benchmarks for those indices, they would provide practitioners with a method for evaluating the degree to which assumption violation is problematic for their data diagnostic purpose.

Sensitivity analyses for the principal ignorability assumption using multiple imputation.

In the context of clinical trials, there is interest in the treatment effect for subpopulations of patients defined by intercurrent events, namely disease-related events occurring after treatment initiation that affect either the interpretation or the existence of endpoints. With the principal stratum strategy, the ICH E9(R1) guideline introduces a formal framework in drug development for defining treatment effects in such subpopulations. Statistical estimation of the treatment effect can be performed based on the principal ignorability assumption using multiple imputation approaches. Principal ignorability is a conditional independence assumption that cannot be directly verified; therefore, it is crucial to evaluate the robustness of results to deviations from this assumption. As a sensitivity analysis, we propose a joint model that multiply imputes the principal stratum membership and the outcome variable while allowing different levels of violation of the principal ignorability assumption. We illustrate with a simulation study that the joint imputation model-based approaches are superior to naive subpopulation analyses. Motivated by an oncology clinical trial, we implement the sensitivity analysis on a time-to-event outcome to assess the treatment effect in the subpopulation of patients who discontinued due to adverse events using a synthetic dataset. Finally, we explore the potential usage and provide interpretation of such analyses in clinical settings, as well as possible extension of such models in more general cases.

Multiply Robust Estimation of Causal Effects under Principal Ignorability

AbstractCausal inference concerns not only the average effect of the treatment on the outcome but also the underlying mechanism through an intermediate variable of interest. Principal stratification characterizes such a mechanism by targeting subgroup causal effects within principal strata, which are defined by the joint potential values of an intermediate variable. Due to the fundamental problem of causal inference, principal strata are inherently latent, rendering it challenging to identify and estimate subgroup effects within them. A line of research leverages the principal ignorability assumption that the latent principal strata are mean independent of the potential outcomes conditioning on the observed covariates. Under principal ignorability, we derive various nonparametric identification formulas for causal effects within principal strata in observational studies, which motivate estimators relying on the correct specifications of different parts of the observed-data distribution. Appropriately combining these estimators yields triply robust estimators for the causal effects within principal strata. These triply robust estimators are consistent if two of the treatment, intermediate variable and outcome models are correctly specified, and moreover, they are locally efficient if all three models are correctly specified. We show that these estimators arise naturally from either the efficient influence functions in the semiparametric theory or the model-assisted estimators in the survey sampling theory. We evaluate different estimators based on their finite-sample performance through simulation and apply them to two observational studies.

Influence of Choices of Statistical Models on Neural Spike Trend

The Center for Neural Interface Design of the Biodesign Insti- tute at Arizona State University conducted an experiment to investigate how the central nervous system controls hand orientation and movement di- rection during reach-to-grasp movements. ANOVA (Analysis of Variance), a conventional data analysis widely used in neural science, was performed to categorized dierent neural activities. Some preliminary studies on data analysis methods have shown that the principal assumption of ANOVA is violated and some characteristics of data are missing from taking the ra- tio of recorded data. To compensate the deciency of ANOVA, ANCOVA (Analysis of covariance) is introduced in this paper. By considering neural ring counts and temporal intervals respectively, we expect to extract more useful information for determining the correlations among dierent types of neurons with motor behavior. Comparing to ANOVA, ANCOVA can be one step further to identify which direction or orientation is favored during which epoch. We nd that a considerable number of neurons are involved in movement direction, hand orientation, or both combined, and some are signicant in more than one epoch, which indicates there exists a network with unknown pathways connecting neurons in motor cortex throughout the entire movement. For the future studies we suggest to integrate this study into neural networking in order to simulate the whole reach-to-grasp process.

Психологічні особливості саморегуляції керівників установ виконання покарань Державної кримінально-виконавчої служби України

The article addresses the problem of a current trend in foreign and domestic psychological science which is self-regulation among professionals working under extreme conditions. Self regulation in risk situations plays a crucial role in making decisions and choosing strategies of behavior under conditions of uncertainty, which is not only a rational process implemented by cognitive mechanisms but also an emotional process including people’s attitudes toward a situation. A set of extreme professions includes service of managers in the penitentiary service, which is associated with emotionally intense social activity and involves a constant presence of pronounced negative stressors. Studying the problem of self-regulation related to the interaction of managers with the socium of extreme nature focuses on answering the key question: What psychological and situational factors contribute to a sufficient level of self-regulation for successful activities under stress conditions? To analyze the system of self-regulation among managers in the penitentiary service we conducted a research using 6 standardized psychodiagnostic technique: Behaviour Self-Regulation Style (V. I. Morosanova, E. M. Konoz); Burnout Assessment, adapted by A. A. Rukavishnikov; Personal Aggressiveness and Propensity to Conflicts (E. P. Ilyin and P. A. Kovalev); Rapid Evaluation of Management Potential (N. P. Fetiskin, V. V. Kozlov, G. M. Manuylov); Evaluation of Communicative and Organizational Aptitudes (V. V. Sinyavsky and B. A. Fedorishin); Orientation Styles of Professional Communication (N. P. Fetiskin, V. V. Kozlov, G. M. Manuylov). The principal assumption in this research was that the structure of individual features of self-regulation (a self-regulation style) and its levels was determined by one’s personal characteristics and professional-environmental factors. The study objectives were: to identify the relationship between the level of self-regulation, overall mental state, and management potential in managers involved in extreme activity (working in the penitentiary service); to reveal psychological factors for optimization of managerial competencies under extreme conditions of professional activity; and to identify main difficulties and competence deficiencies for subsequent corrective and psychotherapeutic interventions. The research conducted enabled us: to study in details the peculiarities of self-regulation, overall mental state, and management potential among managers in the penitentiary system; and to determine which system components require intentional development in order to mitigate deficiencies and to increase the effectiveness of managers. Key words: self-regulation; manager; professional competence; extreme profession; penitentiary service.

Empirically based minimalistic model for representing seasonal phytoplankton dynamics

Supported by chl a satellite data in the North Atlantic (and phytoplankton division rates computed from that data), the disturbance-recovery hypothesis for the initiation of phytoplankton blooms posits that the change in chl a concentration is proportional to the relative change in the phytoplankton division rate. We used this hypothesis, introduced by Behrenfeld, as a principal model assumption and constructed a non-autonomous ordinary differential equation model for seasonally varying chl a concentrations. Our quantitative comparison between model simulations and in situ measurements of chl a and primary production collected from a Swedish fjord was 2-fold: first, using approximate Bayesian computations, we found distributions of values for the 3 model parameters that best described the chl a data. Then, we validated our model by comparing the simulated (not fitted) division rate to the division rate determined from the data. Our minimalistic model was able to capture (1) the yearly trend in the chl a concentration, (2) the pattern of growth and decline in the phytoplankton division rate, and (3) the decreasing trend in the relative change of the division rate exhibited in the data for several individual years. Moreover, the modeling efficiency was positive (between 0.3 and 0.9 with an average of 0.63) for all 11 yr included in this study. We conclude that the change in chl a concentration being proportional to the relative change in the division rate is a possible explanation for the bloom dynamics in the Gullmar fjord. In addition, our work provides a simple and empirically based differential equation for representing yearly dynamics of primary production, e.g. for generating ecological hypotheses using models of other trophic levels.

Impacts of Situational Factors on Consumers’ Adoption of Mobile Payment Services: A Decision-Biases Perspective

ABSTRACT The academic community has accumulated rich knowledge on key mobile payment service (MPS) characteristics that significantly influence consumer adoption. However, a principal assumption underlying the extant literature is that consumers work within a rational decision-making paradigm when making MPS adoption decisions. There is little MPS adoption research that empirically tests consumer adoption behavior from the alternative decision-biases perspective. Our findings demonstrate that MPS adoption behavior is a result of interactions between MPS characteristics and situational factors (i.e., purchase intention and time pressure). Further, our findings suggest that consumers’ decisions on MPS adoption do not necessarily adhere to rational behavior expectations and there are boundaries to conditions where rational MPS adoption decisions apply. Lastly, our findings reveal that situational factors interactively influence MPS adoption decisions.

On the Crack Quasi-Static Growth

The theoretical model of quasi-static crack growth in the elastic-plastic material under load variation in a wide range. Small-scale yielding is principal assumption and main restriction of proposed theory. The model of crack growth provides for continues and interrelated both the crack propagation and plastic deformation development. The nonlinear first-order differential equation describes the quasi-static process of crack growth. In dimensionless form this equation invariant in respect to geometrical configuration and material. The critical size of the plastic zone is proposed as the characteristics of material resistance which is directly connected with the fracture toughness, but more convenient in practical applications of invariant equation. The demonstration of solution is performed for the double cantilever beam that widely used as the standard (DCB) sample for measurement of the mode-I interlaminar fracture toughness. he short analysis of some properties of solution of the invariant equation and its application is done.

ОСОБЕННОСТИ ПСИХОЛОГИЧЕСКОГО КОМПОНЕНТА ГЕСТАЦИОННОЙ ДОМИНАНТЫ, ВНУТРИСЕМЕЙНЫХ ОТНОШЕНИЙ И РОДИТЕЛЬСКИХ УСТАНОВОК У ЖЕНЩИН В СВЯЗИ С ВОЗРАСТОМ И СТАТУСОМ (БЕРЕМЕННЫЕ И НЕ БЕРЕМЕННЫЕ)

Pregnancy is a special period of a woman’s development, characterized by the acceptance of the new social role and changes in behavioral patterns based on parental attitudes, representations of motherhood, and social expectations. This study aims to analyze age differences in the types of psychological component of the gestational dominant (PСGD) and parental attitudes of women in different states (pregnant and non-pregnant). The principal assumption is that the age and the current state have a profound effect and determine different types of PСGD. Additionally, the associations between types of PCGD and parental attitudes are analyzed. The research sample consists of 436 women aged from 18 to 40, divided into two sub-groups: pregnant women (203) and non-pregnant women with a child not older than five (233). Methods: «Parental Attitude Research Instrument» (РARI) and questionnaire «Types of psychological component of the gestational dominant»; ANOVA, t-test, correlation and cluster analysis were used as statistical methods. The main conclusion is that differences in parental attitudes and types of PCGD mainly depend on the women’s age. Younger women (not older than 21) have more negative emotions linked with the intra-family relations (relationship with their husband) and the child’s upbringing. In addition, younger women perceive depression as the central psychological component of the gestational dominant. Regardless of the age, emotional characteristics of the family relations correlate with more adaptive types of PCGD, while non-adaptive types of PСGD are mainly associated with the emotions concerning interaction with the child.

Prediction of cutting force by using ANFIS

The aim of this research is to develop a model to predict the cutting forces of a turning operation. This paper focuses on to design a monitoring system that can recognize cutting force on the basis of cutting parameters like spindle speed, feed and depth of cut by using adaptive neuro-fuzzy inference system (ANFIS). Cutting force is one of the important characteristic variables to be watched and controlled in the cutting processes to determine tool life and surface roughness of the work piece. The principal assumption was that the cutting forces increase due to the wearing of the tool. So, ANFIS model is used to express the cutting force signal. In this paper, ANFIS is used to predict the cutting force. The correlation coefficient (R) and average percentage error found in this modeling are 0.9976 and 2.59% respectively. The predicted cutting force values derived from ANFIS were compared with experimental data. The comparison indicates that the ANFIS achieved very satisfactory accuracy. The correlation coefficient (R) and average percentage error found in this modeling are 0.9976 and 2.59% respectively. The prediction accuracy of ANFIS reached is as high as 97%.

Statistical primer: basics of survival analysis for the cardiothoracic surgeon.

Survival analysis incorporates various statistical methods specific to data on time until an event of interest. While the event is often death, giving rise to the phrase 'survival analysis', the event might also be, for example, a reoperation. As such, it is sometimes referred to as 'time-to-event analysis'. Censoring sets survival analysis apart from other analyses: at the end of the follow-up period, not all subjects have experienced the event of interest, and some subjects may drop out of the study prior to completion. Survival data for a group of subjects is usually visualized by the Kaplan-Meier estimator, representing the probability of a subject remaining free of the event during follow-up. There are several methods to compare survival between the study groups, for example, treatment arms, including the log-rank test and the Cox proportional hazards model. The log-rank test is an unadjusted non-parametric method, whereas the Cox proportional hazards model allows comparison while adjusting for multiple covariates. A principal assumption of the Cox proportional hazards model is that the relative hazard stays constant over time-the so-called proportionality. Specific methods exist for comparison of survival with the general population. This article describes the fundamental concepts every cardiothoracic surgeon should be aware of when analysing survival data and are illustrated with a clinical example.

Basic Principles for the Construction of Dynamic Models of the Planetary Gears Used in Drilling Rigs

Questions regarding the construction of discrete dynamical models are considered, using as an example 2K-N planetary gears with different types of stop couplings and their analytic dynamic models are presented. The principal assumption adopted in the creation of dynamic models of the types of simple planetary gears used in drilling rigs involves the supposition that the motion of the planetary wheel may be decomposed into two types of rotation, first, about the natural axis and, second, about the common axis of the reducing gear (carrier). An evaluation of the assumption is given.

Empirical Low-Rank Approximation for Seismic Noise Attenuation

The low-rank approximation method is one of the most effective approaches recently proposed for attenuating random noise in seismic data. However, the low-rank approximation approach assumes that the seismic data has low rank for its $f-x$ domain Hankel matrix. This assumption is seldom satisfied for the complicated seismic data. Besides, the low-rank approximation approach is usually implemented in local windows in order to satisfy the principal assumption required by the algorithm itself. When implemented in local windows, the rank is even more difficult to choose because the seismic data is highly nonstationary in both time and spatial dimensions and the optimal rank for different local windows is not consistent with each other. In order to preserve enough useful energy, one needs to set a relatively large rank when implementing the low-rank approximation method, which makes the traditional method incapable of attenuating enough noise. Considering such difficulties described above, we propose an empirical low-rank approximation approach. We adaptively decompose the input data into several components that have truly low ranks via empirical mode decomposition. An interpretation of the proposed empirical low-rank approximation method is that we empirically decompose a multi-dip seismic image that is not of low rank into multiple single-dip seismic images that are low-rank individually. We use both synthetic and field data examples to demonstrate the superior performance of the proposed approach over traditional alternatives.

The “hamburger” story; or on Anglicisms in Polish

Abstract The paper makes an attempt to analyse the forms of co-functioning of world languages, taking into account the fact that popular prestigious languages exert influence upon a number of less popular ones, thereby dictating the forms of their further development. Thus, the thesis that media-favoured languages used by politically salient super-powers effectively influence the expressions accepted in a number of “less successful” languages is identified, evidenced and diagnosed. Furthermore, the latter part of the paper stresses the issues concerning the observation that English, recognized as the most prominent donor language, creates many forms of description generally used in many other languages to denote and define similar forms of experiences. Research aimed at discovering the ways in which English influences recipient languages, in this case Polish, was carried out. Our principal assumption was that there exist at least two types of numerous contacts between a donor and recipient language: ones that can be called external (when the donor language mostly influences the recipient one) and ones possibly labelled as internal (when various, normally observed forms of co-operation between the two languages can be traced). As in both cases some semantic bonds can be found, the subsequent research describes said bonds, naming them and uncovering the nature of such co-existence. The results of the research indicate clear forms of semantic co-existence showing that numerous borrowings and loanwords found in the recipient language are widely verbalized and deeply ingrained in the cultural linguistic interdependencies.

Rural Migration in the Developing Economy and its Reflection on the Urban Structure (with Reference to Kurdistan Region)

Indeed ,a lot of common lines bringing different experiences of the developing countries (in respect to rural migration) that are closed to each other, however each experience has its special characteristics which are not necessarily congruent to other experiences as has really been taken place during 1980s in Kurdistan region. To deal with practical aspects ofurbanization in Kurdistan region, a simple questionnaire conducted in two urban areas; Sulaimany (city) and Koya (town). The questions were immediately related to the prospected causes and consequences of migration and urban localization. The research directed to test (qualitatively with reference to the questionnaire results) a principal assumption ;( aversion of migration and urban attractions, both of them resulted in a dichotomous process of settlement). In so far this paper concentrated on the following subjects; One – Rural centrifugal forces of migration. Two –Governmental Obligatory and Urban centripetal forcesof migration. Three- Urbanization and immigration consequences. Four – Towards a sound urbanization in the developing economy. Lastly, the paper concluded that after a long and sluggish rural migration in Iraq during 1950s, 1960s and 1970s governmental obligatory forces in the second half of 1980s represented the most decisive and profoundly determinants of the rural migration in the IKRand this , as a basic consequence, entails a chronic restless to reside between the village and the city.

In support of the Matrix Language Frame Model: Evidence from Igbo-English intrasentential code-switching

ABSTRACTThis article explores the morphosyntactic features of mixed nominal expressions in a sample of empirical Igbo-English intrasentential code-switching data (i.e. codeswitching within a bilingual clause) in terms of the Matrix Language Frame (MLF) Model. Since both Igbo and English differ in the relative order of head and complement within the nominal argument phrase, the analysed data seem appropriate for testing the veracity of the principal assumption underpinning the MLF Model: the notion that the two languages (in our case Igbo and English) participating in code-switching do not both contribute equally to the morphosyntactic frame of a mixed constituent. As it turns out, the findings provide both empirical and quantitative support for the basic theoretical view that there is a Matrix Language (ML) versus Embedded Language (EL) hierarchy in classic code-switching as predicted by the MLF Model because both Igbo and English do not simultaneously satisfy the roles of the ML in Igbo-English code-switching.

Study of Local Matching-Based Facial Recognition Methods Using Thermal Infrared Imagery

This paper shows a comparative study among different local matching-based methods for thermal infrared face recognition. The principal assumption of this work is that the thermal face corresponds to the diffuse energy emission captured by an infrared camera, where the thermal signature is unique for each subject and it can be addressed as a texture descriptor with thermal images. Local matching-based methods find inter-class differences that improve the face recognition rate in thermal spectrum. Specifically, this work considers four methods: Local Binary Pattern (LBP), Local Derivative Pattern (LDP), Weber Linear Descriptor (WLD) and Histograms of Oriented Gradients Descriptors (HOG). The methods are evaluated and compared using the UCHThermalFace database, that considers real-world conditions and unconstrained environments, such as indoor and outdoor setups, natural variations in illumination, facial expression, pose, accessories, occlusions, and background. Results indicate that HOG variants followed by LBP method achieved the best recognition rates for face recognition systems.