Particular Frame Of Reference Research Articles

A shear and elongational decomposition approach of the rate-of-deformation tensor for non-Newtonian flows with mixed kinematics

We propose a novel approach for non-Newtonian viscoelastic steady flows based on a decomposition of the rate-of-deformation tensor which here, in a simplified version, leads to an anisotropic generalised Newtonian fluid-like model with separated treatment of kinematics pertaining to shear and extensional flows. Care is taken to assure that the approach is objective and does not introduce spurious effects due to dependence on a specific reference frame. This is done by separating the rate-of-deformation tensor into shear and elongational components, with the local scalar shear and elongation rates being the second invariant of each tensor separately, and by modifying the method used to separate the rate-of-deformation tensor so that it becomes independent of superimposed rigid rotations, thus satisfying the principle of material indifference. We assess the model with two test cases: planar contraction flow, often employed to evaluate numerical methods or constitutive equations and for which experimentally observed corner vortex enhancement and pressure drop increase are seldom found in numerical simulations; and flow past confined or unconfined cylinders, for which experiments indicate a drag increase due to elasticity and most predictions give a drag decrease. With our anisotropic model, incorporating additional elongational-flow-related terms, large vortices and accentuated pressure drop coefficients can be predicted for the contraction problem and enhanced drag coefficient for the cylinder problems. This is the first work where problems of non-Newtonian fluid mechanics are solved numerically with separation of strain rate into shear and elongational components.

Diens van barmhartigheid of diakonaat – hoe belangrik is ’n naam?

Churches hold different views regarding the office of deacon and role of deacons in the church. Churches also use different terms for their social ministries. This lack of a common language regarding the church’s diaconal ministry often creates confusion in the ecumenical discourse on the diaconate of the church. This article explores the hypothesis that the conceptualisation of a church’s diaconal ministry is influenced by a specific frame of reference, be it a historical perspective, a specific theology or tradition. In this case study of the Dutch Reformed Church (DRC) it is shown how a specific historical and theological understanding of diaconal ministry determines not only this church’s preference for the term ‘service of compassion’ but also its diaconal praxis. The article concludes with a suggestion to the DRC to consider the use of the concept diakonia in contemplation of more active participation in ecumenical disourses regarding the diaconate of the church.Intradisciplinary and/or interdisciplinary implications: The article describes how a specific historical and theological understanding of diaconal ministry determines not only the DRC’s preference for the term ‘service of compassion’ but also its diaconal praxis. The suggestion to more actively participate in developing a common understanding of diakonia ecumenically has implications for the DRC’s ecclesiology, as well as its missional and social ministries.

Regulatory Annexation: Extending Broadcast Media Regulation to Social Media and Internet Content

This article considers the regulation of social media usage in Nigeria and Africa, drawing from ideas on critical political economy, securitization, and state–citizen distrust. Using a methodology that combines policy analysis, case studies, and qualitative reading of social media texts, it introduces for the first time the concept of regulatory annexation. This is the extension of standards, principles, and sanctions originally meant for one particular frame of reference to another. I establish the concept by drawing from case studies on broadcast media regulation to show that this is being mapped onto the emerging regulation of social media and Internet content in what I describe as the politics of regulation. I argue that regulatory annexation bears significant implications for the control of the entire media architecture and our understanding of new media regulation in the wider sense, both now and in the future.

A Qualitative Case Study on Deconstructing Presence for Young Adults and Older Adults

Abstract In this paper, we present the results of an exploratory qualitative case study on presence experienced by groups of young adults and older adults during their use of an interactive virtual reality application mixing realistic and fantasy elements. In contrast to most previous studies, we do not focus on a set of predetermined factors but instead adopt an open-ended qualitative approach to identify emerging factors from the users' experiences. We then analyze these factors against the place illusion/plausibility illusion (PI/PSI) framework of Skarbez, Neyret, et al. (2017) to investigate whether PI and PSI, as well as their contributing factors, can be separated. According to our findings, a user can experience PI and PSI independently from each other; however, they often appeared intermixed when investigated on the scope of the whole experience. Breaks in presence, as well as breaks in plausibility, could mostly, but not entirely, be attributed to immersion and coherence factors, respectively. An interesting finding is that both participant groups turned out to have two subgroups interpreting their experience with a particular frame of reference of differing expectations. These frames of reference affected not only PSI, as expected, but PI as well, suggesting that coherence could be a contributing factor to both PI and PSI. Our contribution adds to the relatively small body of research investigating the separation of PI and PSI. Our exploratory findings can be utilized as directions for designing future confirmatory studies.

RESEARCH OF THE INERTIAL DEVIATION MEASUREMENT SYSTEM UAV CARGO FROM ZERO POINT

Inertial measurement units (IMUs) can consist of one or more sensors that collect data designed to measure inertial motions in a specific frame of reference. Acceleration, rotational speed are examples of data that can be obtained from the sensors contained in the IMU. IMUs can be found in a variety of smart devices, medical rehabilitation, general robotics, UAV control and navigation enhancement systems, sports devices, and virtual reality systems. Some engineering solutions and displacement sensors have a number of limitations, such as systems that do not have a clear initial reference point. In such systems, it is difficult to track deviations from the starting point. However, the acceleration of a moving object is usually easy to measure, so the given deflection of the object can easily be obtained using the integral of the acceleration. To solve such problems, a distance measurement system based on a microelectromechanical system (MEMS) accelerometer has been developed. The hardware structure of the system includes a data measurement module and integrated data collection and data processing modules. Due to the physical properties of the sensor, such a system can be used in a small space, with large overloads and other adverse conditions. This article describes a system calibration method and proposes a deviation tracking algorithm based on acceleration integration. Fixed output error caused by sensor mounting position is analyzed. The analysis shows that if this factor is not taken into account, the error will lead to a serious error. The experiment of measurement of the deviation from the zero point is carried out on a horizontal, flat surface, and the calculation results show that the average accuracy of the deviation measurement of this system can reach 99.05%. The results of the experiment indicate the feasibility of the system in the conditions of short-term free fall and the validity of the data processing algorithm. The accuracy of the distance measurement system can meet most engineering needs.

Flexible control of grid-connected renewable energy systems inverters under unbalanced grid faults

The sustainable energy opportunity of the future lies in the renewable energy-based distributed Power Generation systems (DPGSs). However, there are different concerns and integration issues that surround them. To increase the rate at which renewable energy can be used, this paper focuses on an integrated utility grid system. A novel strategy to control the grid side inverter is developed for a DPGS when considering an unbalanced grid. First, an analysis of the consequences of the occurrence of a fault on the grid is performed. Secondly, a control strategy is proposed to ensure the operation of the DPGS connected to the grid even if the latter is unbalanced. The proposed approach consists in developing control loops for each of the three symmetrical sequences in a specific reference frame to ensure the operation of the grid-connected DPGS even during asymmetrical grid voltage fault. The found results are promising in terms of the guarantee of service continuity during faulty conditions.

Topological hydrodynamic modes and holography

We study topological modes in relativistic hydrodynamics by weakly breaking the conservation of energy momentum tensor. Several systems have been found to have topologically nontrivial crossing nodes in the spectrum of hydrodynamic modes and some of them are only topologically nontrivial with the protection of reflection symmetries in two directions. The nontrivial topology for all these systems is further confirmed from a calculation of the topological invariant. Associated transport properties and second order effects have also been studied for these systems. The nonconservation terms of the energy momentum tensor could come from an external effective symmetric tensor matter field or a gravitational field which could be generated by a specific noninertial reference frame transformation from the original inertial reference frame. Finally we introduce a possible holographic realization of one of these systems. We propose a new method to calculate the holographic Ward identities for the energy momentum tensor without calculating out all components of the Green functions and match the Ward identities of both sides.

Do Physical Education Teachers Use Socioconstructivist Communication Patterns in Their Classes?

Purpose: This study aims to identify socioconstructivist communication patterns used by physical education teachers and their evolution after participating in a training intervention. Method: The authors analyzed 812 units (messages containing constructivist discursive strategies) employed by two physical education teachers in two teaching modules using observational methodology. The data were analyzed by polar coordinate analysis. Results: In the pretraining phase, Teacher 1 presents two discursive patterns with questions–answers–literal incorporation of student-answers into the teachers’ communication, and another formed by praise questions. Teacher 2 generated praise-questions only. In the posttraining phase, Teacher 1 maintains one of the initial patterns and generates another consisting of questions-incorporation of students’ actions into the teacher’s communication. Teacher 2 incorporates two new patterns composed of information demands that are associated with the use of a specific frame of reference, or meta-statement. Discussion: The use of polar coordinate analysis revealed the presence of communication patterns and their evolution. Conclusion: The training intervention has resulted in changes in the communicative patterns of teachers. The custom-made instrument has allowed knowing the discursive strategies

Du macro-outillage tranchant utilisé en percussion lancée dans les premières phases de l’Acheuléen européen ? Le cas de l’US4 de Bois-de-Riquet (Lézignan-la-Cèbe, Hérault, France)

Level US4 of the Bois-de-Riquet archeological site represents a mudslide type deposit dating to the early Middle Pleistocene. It has yielded a rich lithic assemblage made from basalt, aplite and quartz, whose components represent all of the operating chains of production: cores, flakes, hammers, worked cobbles and blocks, as well as a biface. The latter, associated with the production of large flakes, testifies to the first phases of the European Acheulian. This article presents the analysis of part of the macro-tools made from basalt. The methodology is based on a techno-morpho-functional and traceological analysis of the artefacts, coupled with the creation of a specific experimental frame of reference. These approaches allow us to distinguish among five tool types. Three groups of tools present a transverse opposition between their cutting edges and gripping zones, while the other two groups present an oblique opposition. These functional structures refer to different gestures. However, the size and weight characteristics of the artefacts, as well as the angle of the cutting edges, allow us to propose a mode of action in direct launched percussion. This hypothesis was experimentally tested on wood and fresh bone to verify, on the one hand, the effectiveness of these tools for these activities and, on the other hand, to analyze the damage produced on the cutting edges and compare it to the archeological tools. The data obtained experimentally support the hypothesis that launched percussion was used in these five groups of sharp-edged macro-tools. We discuss the implications of these results for the characterization of the first phases of the European Acheulean. Indeed, beyond the presence of a biface, the production of massive flakes as tool supports may be perceived as a technological innovation in Europe, possibly characterizing an evolution of cognitive order. At the same time, the use of these sharp tools in launched percussion could indicate that hominins were exploiting their environments in new ways. Finally, this article brings new elements of reflection to the debate on the origins of the European Acheulean.

Practical Algorithms on Lunar Reference Frame Transformations for Korea Pathfinder Lunar Orbiter Flight Operation

This technical paper deals the practical transformation algorithms between several lunar reference frames which will be used for Korea pathfinder lunar orbiter (KPLO) flight operation. Despite of various lunar reference frame definitions already exist, use of a common transformation algorithm while establishing lunar reference frame is very important for all members related to KPLO mission. This is because use of slight different parameters during frame transformation may result significant misleading while reprocessing data based on KPLO flight dynamics. Therefore, details of practical transformation algorithms for the KPLO mission specific lunar reference frames is presented with step by step implementation procedures. Examples of transformation results are also presented to support KPLO flight dynamics data user community which is expected to give practical guidelines while post processing the data as their needs. With this technical paper, common understandings of reference frames that will be used throughout not only the KPLO flight operation but also science data reprocessing can be established. It is expected to eliminate, or at least minimize, unnecessary confusion among all of the KPLO mission members including: Korea Aerospace Research Institute (KARI), National Aeronautics and Space Administration (NASA) as well as other organizations participating in KPLO payload development and operation, or further lunar science community world-wide who are interested in KPLO science data post processing.

From Dublin descriptors to implementation in Bachelor labs

A description of the implementation of a completely renewed setup for Physics Bachelor labs is given. The renewed setup made use of the latest educational research insights and is described from the general Dublin descriptors and the CALOHEE assessment and National domain specific reference frame up to the concrete learning objectives that we aim for in the Bachelor practicals. A choice between more open and closed labs is discussed. This study makes use of educational design research and therefore mostly tests design principles. In general, the design principles behind the renewed setup have worked and students have been given a need to perform each step in the research process. Despite the courses becoming more challenging, students’ results have gone up. We attribute this to specific types of iterations within the closed practicals and on the alternation between closed and open labs. Overall, most students attained the experimental skills that we aimed for and by the end of the practicals in year 2 most students also obtained the most relevant CALOHEE dimension of ‘Experimental design and scientific inquiry’, designed to assess students after year 3. The remaining obstacles are identified and suggestions for future improvements are given.

Perceived Self-Control Effort, Subjective Vitality, and General Affect in an Associative Structure.

A crucial assumption of the recently developed schema model of self-control is that people’s perceived self-control efforts are related to the experience of lowered subjective vitality. In the present study, this assumption was tested. It was also examined whether perceived self-control effort is related to a diffuse affective experience (i.e., subjective vitality, general positive affect, and general negative affect as a combined factor) or is discretely related to subjective vitality, general positive affect, and general negative affect. Based on the previous literature, it was expected that the latter would better fit the data. In a survey study, university students (N = 501) completed standardized measures of their perceived self-control effort, subjective vitality, general positive affect, and general negative affect with regard to a specific frame of reference (i.e., during the current day and the last 2 days). Bivariate correlations and confirmatory factor analyses revealed the expected relationships, meaning that perceived self-control effort was negatively related to subjective vitality and that the statistical model with three distinct affective variables fit the data better than the model with subjective vitality, positive affect, and negative affect incorporated into one common factor. It was concluded that the findings are in line with the schema model of self-control.

Echoes from the Great Divide: On the Faltering Philosophical Dialogue between Africa and the West

Even in the field of comparative or cross-cultural philosophy, distinctive contributions by African philosophers are often side-lined – that is, relegated to niche publications. Why is it so hard for African philosophers to draw their Western colleagues (other than specialists in African philosophy) into a real dialogue? An attempt is made to describe the field of tension; it is shown that some of the reflexes that manifest themselves in it reveal not just the attachment to specific perspectives or frames of reference, but also implicit ideas about the nature of the “philosophical game”. On the Western side, motives constitutive of practical or traditional life are either ignored or tacitly equated with attempts to realize goals that can be best understood from a reflexive point of view. In this way, the concrete conditions of any human activity, including intellectual activity, are lost from view. This critical lesson has been spelt out by a number of philosophers (Maurice Blondel being one of them), but is seldom taken to heart. As a result, it becomes difficult to penetrate beyond conceptual differences. It will also be maintained that while many African philosophers question intellectualist attitudes, they do not always do so in a way that invites discussion on the central, or basic, issues.

Spatial variability and possible cause analysis of regional precipitation complexity based on optimized sample entropy

AbstractSample entropy can be used to investigate the complexity of precipitation series. However, the randomness of similar tolerance selection may lead to inaccurate results. To solve this problem, the distinction degree theory was introduced to optimize the similar tolerance of sample entropy, and a specific reference frame for the optimization process was provided. The optimized sample entropy was used to study the spatial differences in precipitation complexity and the possible causes from the perspective of the monthly precipitation (MP) and extreme daily precipitation (EDP) in Heilongjiang Province, China. The results demonstrated that the MP and EDP in Heilongjiang Province both had unsteady complex fluctuation characteristics and the optimal similar tolerances of the sample entropy were 0.24 and 0.13 times the standard deviation, respectively. The complexity of the EDP was higher than that of the MP, and their fluctuation ranges were 1.641–2.268 and 0.433–0.870, respectively. The complexity of the MP in the study area could be spatially represented as a basic pattern, which gradually decreased from east to west. The spatial distribution pattern of the EDP complexity indicated that the northern part was higher than the southern part. Altitude was the common influencing factor of the MP and EDP complexities, and it had a greater impact on the spatial pattern of the EDP complexity. Potential factors influencing the spatial difference in MP complexity also included changes in precipitation intensity, water area and residential and industrial land areas. Except for altitude, industrial economic development level may also affect the complexity of the EDP. The results may improve the application of sample entropy in climate system complexity measurements and could provide guiding significance for revealing the spatial variation of precipitation complexity.

ENGLISH-A COMPARATIVE STUDY OF VARIANCES IN THE NATURE OF HUMAN DISPOSITION IN GHAZALIAN THEORY OF SOUL AND FREUDIAN PSYCHOANALYSIS

The present study aims at providing the venue to the mystical insights of Ghazalian theory of soul to be integrated into the study of Freudian psychoanalysis, with its principal emphasis on the variances between them. Moreover, the foundational belief of this research proceeds from the assumption that although Freudian psychoanalytic theory has enriched the world with its insightful psychological interpretations, correspondingly appropriate appraisals result from analyzing Ghazalian theory of soul. This study adopts the descriptive and analytic methodology to investigate the variances in both the models and has been developed according to the guidelines provided by Zepetnek’s (1998) theory of comparative literature. The findings of the study reveal that despite certain profound similarities in Ghazlain theory of soul and Freudian psychoanalysis, there exist some variances arising out of specific settings and distinct frames of reference in which these theories are produced. This analytical approach may lead to an alternative critical agenda for the better understanding of human mind.

Picture and text: on the “iconography” of sacred spaces in middle-Byzantine ekphraseis

Abstract The present contribution engages with two representative examples of middle-Byzantine ekphraseis, Photios’ description of the Virgin of the Pharos and Leo VI’s account of the church founded by Stylianos Zautzes. It aims at showing how these texts suggest modes of viewing the sacred space and decoration that pose, more than settle, questions about images and pictures, their intended function, significance and impact within their specific cultural frames of reference. Far from being neutral and disengaged, these verbal representations have a specific agenda, which inflects the audience’s perception and interpretation of the decorated church space. Comparisons with coeval monumental evidence are also offered, in order to analyze textual and visual developments in parallel.

The retrospective pretest–posttest design redux: On its validity as an alternative to traditional pretest–posttest measurement

We revisit the merits of the retrospective pretest–posttest (RPP) design for repeated-measures research. The underutilized RPP method asks respondents to rate survey items twice during the same posttest measurement occasion from two specific frames of reference: “now” and “then.” Individuals first report their current attitudes or beliefs following a given intervention, and next they are prompted to think back to a specific time prior to the given intervention and rate the item again retrospectively. The design addresses many of the validity concerns that plague the traditional pretest–posttest design. Particularly when measuring noncognitive constructs, the RPP design allows participants to gauge the degree of change that they experience with greater awareness and precision than a traditional approach. We review the undesirable features of traditional designs and highlight the benefits of the retrospective approach. We offer examples from two recent, original studies and conclude with the recommendation that the RPP design be employed more broadly. We also conclude with a discussion of important directions for future examination of this design.

Comparing Masculinities – True Grit (1968, 1969, 2010)

Abstract By studying three different versions of an American Western narrative, the novel True Grit and its cinematographic adaptations, the essay starts with the plurality of masculinities embodied within the genre to outline the specific reference points, frames, and tertia comparationis that organize and structure these and other male narratives in the 20th and 21st century. While the narrative of True Grit is all about comparing men, each version centers upon a different concept these comparisons are directed toward: a nostalgic imagination of a noble masculine society gone by; a family narrative where men evolve as children, fathers, and potential husbands; a threatening masculinity representing the dark ‘other’ side of civilization. While taking a plurality of masculinities for granted, this essay aims to identify common frames and narratives of masculinities that allow for structuring the future field of comparative masculinity studies.

Coordinate references for the indoor/outdoor seamless positioning

Abstract. Indoor positioning technologies are being developed rapidly, and seamless positioning which connected indoor and outdoor space is a new trend. The indoor and outdoor positioning are not applying the same coordinate system and different indoor positioning scenes uses different indoor local coordinate reference systems. A specific and unified coordinate reference frame is needed as the space basis and premise in seamless positioning application. Trajectory analysis of indoor and outdoor integration also requires a uniform coordinate reference. However, the coordinate reference frame in seamless positioning which can applied to various complex scenarios is lacking of research for a long time. In this paper, we proposed a universal coordinate reference frame in indoor/outdoor seamless positioning. The research focus on analysis and classify the indoor positioning scenes and put forward the coordinate reference system establishment and coordinate transformation methods in each scene. And, through some experiments, the calibration method feasibility was verified.

THE SUSTAINABLE BRAND EQUITY MODEL. A RETAIL STUDY MEASURING SUSTAINABLE BRAND EQUITY

THE SUSTAINABLE BRAND EQUITY MODEL. A RETAIL STUDY MEASURING SUSTAINABLE BRAND EQUITY