Body Of Theory Research Articles

Development of a Large-Aperture Coordinate Precision Measurement Instrument Using Differential Geometric Error Weighting

The accuracy of traditional measuring machines is affected by the measuring range and sensitive geometric errors, and it is not possible to combine large caliber and high-precision measurements. This study proposes a differential geometric error-weighting method for designing a high-precision, large-diameter measuring machine. The machine utilized a zero-Abbe arm structure and applied the rigid body theory and small-angle hypothesis to model geometric errors. Weights were calculated for 23 geometric errors, identifying eight sensitive ones. A picometer-precision laser interferometer (quDIS) with a theoretical positioning accuracy of 0.2 nm/mm and standard flat rulers are used to ensure highly accurate positioning of the Y-axis/Z-axis of the measuring platform and reduce the straightness of both axes by approximately 75%, with radial and axial runout of the rotary table under 100 nm. The development and design method of the high-precision measuring machine proposed in this study is applicable to large-diameter high-precision flexible measurement, and the accurate control of measuring machine movement accuracy is realized by calculating the geometric error weights.

The nonlinear behavior of generic tail fins for small wind turbines

This paper describes analysis and measurements of the yaw response of tail fins for small wind turbines. It is based on an extension of unsteady slender body theory (USBT) to cover non-slender fins and high angles of incidence, both of which make the theory nonlinear. We provide three main additions to the substantial literature on linearized USBT for tail fins. First, USBT is extended to high angles by modeling the nonlinear vortex dynamics. Second, the restriction to slender bodies is removed by modeling the chordwise load variation. Third, we consider the effect of time-varying wind speed. The extended theory is compared to wind tunnel measurements of the yaw behavior of delta, elliptical, and rectangular tail fins without a rotor and nacelle. The fins were released from initial yaw angles of −40° and −80°; the latter is of sufficient magnitude to show the importance of the nonlinear yaw dynamics. Generally good agreement was found between the theory and measurements, and the theory was shown to be more accurate than a “polar” or quasi-steady model which uses only the lift and drag of a delta planform. Of the three planforms, the rectangular one showed the lowest accuracy in terms of frequency but the damping was accurately predicted. Overall, the results demonstrate the importance of nonlinearity in the response of a yawing tail fin, particularly for the higher aspect ratio fins at large yaw angles.

De-Hydration and Remodeling of Biological Materials: Swelling Theory for Multi-Domain Bodies

Biological materials always exhibit heterogeneous physical properties, both mechanical and chemical, which give them a rich phenomenology that poses significant challenges in the developing of effective models. The Flory–Rehner theory revolutionized our understanding of the dynamics of the liquid-polymers coupling in soft swollen gels, recognizing polymers as elastic networks stretched by the presence of liquid. Despite its foundational role, applying this theory to bodies with non uniform physical properties requires further improvements. This article proposes a unified approach to address mechano-diffusion challenges in multi-domain bodies, that is in material bodies made of regions having different chemo-mechanical properties, and focuses on the dehydration and remodeling of biological-like materials. Drawing inspiration from natural systems, we integrate principles from nonlinear mechanics and swelling theories; in particular, what is specifically new is the idea of applying the notion of the multiplicative decomposition of the strain–developed for plasticity–to model the swelling properties of a body made of two or more materials. The article gives a systematic presentation of the subject, and guides readers through key concepts and practical insights, aiming to provide a robust framework for modeling chemo-mechanical interactions. Moreover, it paves the way for the modeling of heterogenous bodies having spatially-varying properties.

Understanding Embodiment and Existentialism in Contemporary Chinese Dance

This paper employs the theoretical framework of phenomenology of the body to explore embodiment and existentialism in contemporary Chinese dance. With the backdrop of the current status and influence of Chinese contemporary dance in the realm of dance arts, it analyzes the unique forms and techniques of bodily expression in Chinese contemporary dance, attempting to explore how personal emotions, inner experiences, and spiritual states are conveyed through bodily expression in Chinese contemporary dance. The paper utilizes case analysis and observational research methods to delve into the cognition of bodily expression and identity construction in Chinese contemporary dance, as well as how the body is used to reflect on the cognition and positioning of Chinese traditional and modern cultural identities, exploring the diversity and changes in Chinese cultural identity. Finally, by applying Merleau-Ponty's phenomenology of the body theory, it deeply analyzes the significance and existentialism of bodily expression in contemporary Chinese dance, experiencing and understanding the relationship between bodily subjectivity and self through dance. Through these studies, we can gain a deeper understanding of the complexity and diversity of bodily expression in contemporary Chinese dance, enabling dancers to reassess their ability to express emotions, as well as the application and insights of Merleau-Ponty's phenomenology of the body therein.

Theories for Understanding the Effect of Impact Assessment and Project Evaluation on the Practice of Science

We examine the phenomenon of impact assessment in the practice of scientific research, paying attention to the context in which project evaluation is used in federally funded research on plant health in the United States. Our analysis, which is derived from systems theory, carries out a particular view of the research process. For the purposes of this review, our use of the term systems theory references the body of interdisciplinary work that deals with the organization and function of complex structures in nature and human society. Key concepts in this body of theory are that both the components and the interactions among components are important in understanding behavior and that, frequently, systems are seen to be hierarchical in structure. The aim of our analysis is to bring to the attention of the plant health community several concepts from the social sciences that might help in understanding how researchers have responded to the increased expectations from funders to provide project evaluations and impact assessments. We generate a synthesis of these theories, which have not previously been used in a unified way, to explain choices in response to newly imposed goals. Although our analysis is motivated by a specific disciplinary focus on plant health, the issues we discuss are general. Thus, we hope the review is useful to a wide range of scientists, science program managers, and policymakers.

AstroSLAM: Autonomous monocular navigation in the vicinity of a celestial small body—Theory and experiments

We propose AstroSLAM, a standalone vision-based solution for autonomous online navigation around an unknown celestial target small body. AstroSLAM is predicated on the formulation of the SLAM problem as an incrementally growing factor graph, facilitated by the use of the GTSAM library and the iSAM2 engine. By combining sensor fusion with orbital motion priors, we achieve improved performance over a baseline SLAM solution and outperform state-of-the-art methods predicated on pre-integrated inertial measurement unit factors. We incorporate orbital motion constraints into the factor graph by devising a novel relative dynamics—RelDyn—factor, which links the relative pose of the spacecraft to the problem of predicting trajectories stemming from the motion of the spacecraft in the vicinity of the small body. We demonstrate AstroSLAM’s performance and compare against the state-of-the-art methods using both real legacy mission imagery and trajectory data courtesy of NASA’s Planetary Data System, as well as real in-lab imagery data produced on a 3 degree-of-freedom spacecraft simulator test-bed.

The starting vortices generated by bodies with sharp and straight edges in a viscous fluid

A two-dimensional body that moves suddenly in a viscous fluid can instantly generate vortices at its sharp edges. Recent work using inviscid flow theory, based on the Birkhoff–Rott equation and the Kutta condition, predicts that the ‘starting vortices’ generated by the sharp and straight edges of a body – i.e. the vortices formed immediately after motion begins – can be one of three distinct self-similar types. We explore the existence of these starting vortices for a flat plate and two symmetric Joukowski aerofoils immersed in a viscous fluid, using high-fidelity direct numerical simulations (DNS) of the Navier–Stokes equations. A lattice Green's function method is employed and simulations are performed for chord Reynolds numbers ranging from 5040 to 45 255. Vortices generated at the leading and trailing edges of the flat plate show agreement with the derived inviscid theory, for which a detailed assessment is reported. Agreement is also observed for the two symmetric Joukowski aerofoils, demonstrating the utility of the inviscid theory for arbitrary bodies. While this inviscid theory predicts an abrupt transition between the starting-vortex types, DNS shows a smooth transition. This behaviour occurs for all Reynolds numbers and is related to finite-time effects – there is a maximal time for which the (self-similar) starting vortices exist. We confirm the inviscid prediction that the leading-edge starting vortex of a flat plate can be suppressed dynamically. This has implications for the performance of low-speed aircraft such as model aeroplanes, micro air vehicles and unmanned air vehicles.

Towards an ontology of struggle: The Marxist-Humanist theory of social transformation in the work of Raya Dunayevskaya

This article outlines Dunayevskaya’s original but underappreciated contribution to Marxism as a body of theory and practice. Focusing specifically on her Marxist-Humanist ‘ontology of struggle’ in its various dimensions, it draws out her engagement with Marx such that a new, vitalised account of social transformation is elaborated. From her critique of labour and state capitalism to her account of the dual movement between practice and theory, to her attentiveness to the ‘voices from below’ and to the ‘new passions and forces that develop in the bosom of society’, a theory is elaborated that expands the traditional Marxian dialectic to the struggles of racialised groups, women and other minorities. In so doing, it offers a basis from which to re-appraise liberatory politics, and to renew the emancipatory thrust of Marx’s writings.

Deep Domain Adaptation With Max-Margin Principle for Cross-Project Imbalanced Software Vulnerability Detection

Software vulnerabilities (SVs) have become a common, serious, and crucial concern due to the ubiquity of computer software. Many AI-based approaches have been proposed to solve the software vulnerability detection (SVD) problem to ensure the security and integrity of software applications (in both the development and testing phases). However, there are still two open and significant issues for SVD in terms of i) learning automatic representations to improve the predictive performance of SVD, and ii) tackling the scarcity of labeled vulnerability datasets that conventionally need laborious labeling effort by experts. In this paper, we propose a novel approach to tackle these two crucial issues. We first exploit the automatic representation learning with deep domain adaptation for SVD. We then propose a novel cross-domain kernel classifier leveraging the max-margin principle to significantly improve the transfer learning process of SVs from imbalanced labeled into imbalanced unlabeled projects. Our approach is the first work that leverages solid body theories of the max-margin principle, kernel methods, and bridging the gap between source and target domains for imbalanced domain adaptation (DA) applied in cross-project SVD . The experimental results on real-world software datasets show the superiority of our proposed method over state-of-the-art baselines. In short, our method obtains a higher performance on F1-measure, one of the most important measures in SVD, from 1.83% to 6.25% compared to the second highest method in the used datasets.

서예를 활용한 마음 치료 방안 연구

Calligraphy has been emphasized as an art that goes beyond mere functional acquisition, but expressing one’s temperament, character, personality, and emotions. It has evolved from the human nature theory that calligraphy represents one’s heart, establishes a close relationship between calligraphy and emotions, leads to the theory that calligraphy reflects one’s personality. Through the calligraphy theory and narrative activities, clinical experiments have shown that the calligraphy therapy plays a complementary role in treatment of adult diseases, depression, mental disorders, dementia, and autism, and effectively alleviates those symptoms. Therefore, this paper aims to explore therapeutic approaches by examining the relationship between calligraphy and mind, comparing from the stage before holding the brush to the stage at the end of the calligraphy writing with the mind-study methodology of pausing, breathing, observing, recognizing, putting down, and discovering grace. Therefore, this paper examined the process of preparing calligraphy, the process of writing by Phil-bub, the psychological effect according to the calligraphy, and the psychological purification effect through letters, sentences, and famous phrases, which are the contents of calligraphy. It confirmed that calligraphy can serve as an intervention technique in mind therapy beyond its aspects of discipline theory of body and mind. Engaging in calligraphy involves experiences of pause in the process of organizing one’s surroundings and gathering one’s mind before writing It enhances attention through breath control while using Mo-phil, finds peace of mind through concentration during overlapping strokes, and increases sense of accomplishment. Calligraphy is not only good for self-esteem recovery and strengthening immune system but also maximizing physiological activities, and promoting brain function. practicing calligraphy significantly contributes to health promotion.

The problem of the structure and the soil plastic environment interaction in the conditions of dynamic evolutionary processes

Dynamic influences are one of the important factors affecting project decisions during the construction of buildings and structures. In the case of dynamic analysis, the range of possible variations in structural response is very difficult to determine. The complexity is determined not only by the parameters of the load itself (intensity, the law of change over time), but also by the characteristics of the research object (their values and change over time), which is an interconnected system of the structure and the soil base. Dynamic factors of influence can include periodic vibration or shock loads, the effects of explosions that cause a sharp change in pressure on the structure of the building, seismic fluctuations, etc. In many cases, the load is the result of stress waves propagating in the soil base. These factors can act on the natural environment long-term, relatively short-term, short-term and instantaneous. Therefore, the development of refined approaches for assessing the stress-strain state of structures during the interaction of the structure and the soil environment under the conditions of dynamic evolutionary processes remains an actual task today. In order to effectively find a solution to the dynamics problems, it is necessary to possess the entire set of analysis tools, to clearly present the rules and limits of their application. The ability to correctly assess the engineering and geological conditions of the construction site, the properties of the soils, the joint work of these soils with the foundations and structures of the building has always been and remains the basis of reliable and effective engineering design. The given statement of the problem is a theoretical basis to build the numerical approaches to the study of the vibrational processes of heterogeneous spatial bodies during their contact interaction with an elastic-plastic medium. The paper considers the modeling aspects of the structure and the soil elastic-plastic environment interaction under the conditions of dynamic evolutionary processes. The basic geometric and physical equations of the elasticity theory for heterogeneous circular and prismatic spatial bodies are given. In the range of solving the dynamics problem, the peculiarities of the mathematical model implementation, regarding the representation of the variation of kinetic energy as part of the equations of dynamic equilibrium of linear and nonlinear mechanical systems, are considered.

Role Reversals and Permeable Bodies in the Modern Robinsonade: From Postcolonialism to Ecocriticism

This essay argues that the particular lens of Bakhtinian body theory as developed for the Robinsonade by Rebecca Weaver-Hightower will help to shed light on a process observable over the past fifty years, in which colonial and postcolonial authors first embraced and then quickly abandoned the technique of role reversal in drafting their castaway stories. Enamoured of its comedic potential, Adrian Mitchell wrote Man Friday (1973). Derek Walcott was somewhat more circumspect in his Pantomime (1978), based on the realisation that role reversal demands the ascription of univocal roles and identities, something he did not see in evidence in the creolised world of the Caribbean. Later colonial and postcolonial writers such as J. M. Coetzee and Patrick Chamoiseau were then at pains to avoid questions of identity altogether, making epistemology and discourse their preferred topics. By the beginning of the twenty-first century, however, the clichéd identities formerly applied to Indigenous peoples (physical strength, close connection to nature) could be brought to bear on the idea of nature itself, thus making animal Robinsonades such as Life of Pi (2001) and The Red Turtle (2016) tremendous successes that could forgo the messiness of human affairs and simply champion the everlasting superiority of nature over civilisation as an expression of contemporary environmental preoccupations.

Active Inference and Social Actors: Towards a Neuro-Bio-Social Theory of Brains and Bodies in Their Worlds

Although research including biological concepts and variables has gained more prominence in sociology, progress assimilating the organ of experience, the brain, has been theoretically and technically challenging. Formal uptake and assimilation have thus been slow. Within psychology and neuroscience, the traditional brain, which has made brief appearances in sociological research, is a “bottom–up” processor in which sensory signals are passed up the neural hierarchy where they are eventually cognitively and emotionally processed, after which actions and responses are generated. In this paper, we introduce the Active Inference Framework (AIF), which casts the brain as a Bayesian “inference engine” that tests its “top–down” predictive models against “bottom–up” sensory error streams in its attempts to resolve uncertainty and make the world more predictable. After assembling and presenting key concepts in the AIF, we describe an integrated neuro-bio-social model that prioritizes the microsociological assertion that the scene of action is the situation, wherein brains enculturate. Through such social dynamics, enculturated brains share models of the world with one another, enabling collective realities that disclose the actions afforded in those times and places. We conclude by discussing this neuro-bio-social model within the context of exemplar sociological research areas, including the sociology of stress and health, the sociology of emotions, and cognitive cultural sociology, all areas where the brain has received some degree of recognition and incorporation. In each case, sociological insights that do not fit naturally with the traditional brain model emerge intuitively from the predictive AIF model, further underscoring the interconnections and interdependencies between these areas, while also providing a foundation for a probabilistic sociology.

An alternative potential method for mixed steady‐state elastic oscillation problems

We consider an alternative approach to investigate three‐dimensional exterior mixed boundary value problems (BVPs) for the steady‐state oscillation equations of the elasticity theory for isotropic bodies. The unbounded domain occupied by an elastic body, , has a compact boundary surface , which is divided into two disjoint parts, the Dirichlet part and the Neumann part , where the displacement vector (the Dirichlet‐type condition) and the stress vector (the Neumann‐type condition) are prescribed, respectively. Our new approach is based on the classical potential method and has several essential advantages compared with the existing approaches. We look for a solution to the mixed BVP in the form of a linear combination of the single‐layer and double‐layer potentials with densities supported on the Dirichlet and Neumann parts of the boundary, respectively. This approach reduces the mixed BVP under consideration to a system of boundary integral equations, which contain neither extensions of the Dirichlet or Neumann data nor the Steklov–Poincaré‐type operator involving the inverse of a special boundary integral operator, which is not available explicitly for arbitrary boundary surface. Moreover, the right‐hand sides of the resulting boundary integral equations system are vector functions coinciding with the given Dirichlet and Neumann data of the problem in question. We show that the corresponding matrix integral operator is bounded and coercive in the appropriate ‐based Bessel potential spaces. Consequently, the operator is invertible, which implies unconditional unique solvability of the mixed BVP in the class of vector functions belonging to the Sobolev space and satisfying the Sommerfeld–Kupradze radiation conditions at infinity. We also show that the obtained matrix boundary integral operator is invertible in the ‐based Besov spaces and prove that under appropriate boundary data a solution to the mixed BVP possesses ‐Hölder continuity property in the closed domain with , where is an arbitrarily small number.

Sex, Gender, and Devotional Desire: Refiguring Bodily Identities in Gauḍīya Vaiṣṇava Discourse

Many of the debates among theorists of the body in feminist and gender studies center on the gendered body and its relation to the sexed body, with the validity of the sex/gender distinction itself a topic of contention. On the one hand, feminist advocates of social constructionism tend to distinguish between sex and gender, in which sex (male or female) is identified with the biological body as a “natural” datum and gender (masculine or feminine) is a second-order sociocultural construction that is superimposed as an ideological superstructure on this “natural” base. On the other hand, feminist advocates of sexual difference such as Judith Butler call into question the sex/gender distinction and insist that the sexed body, like gender, is socially constructed. This article brings these contemporary feminist interlocutors into conversation with sixteenth-century Gauḍīya Vaiṣṇava authorities who developed a distinctive discourse of embodiment in which they frame the categories of sex and gender in relation to devotional desire in their ontological theories of bodily identities. The Gauḍīya discourse of embodiment explodes notions of the relationship between embodiment, personhood, materiality, and gender on both the human and divine planes and challenges prevailing body theories by positing bodies beyond matter, personhood beyond matter, and gender beyond sex.

On some questions of the theory of the human body

The subject of medical science is human health. Health is a property of the body. This can only be understood within the framework of a theoretical model. To date, such models do not exist; one of the attempts to create it was the theory of functional systems by P.K. Anokhin, however, it was not completed. At the same time, there are no theoretical models of simpler organisms than humans. Moreover, there is no methodology for creating such models. Empirical approaches implemented in private medical sciences, such as physiology, anatomy, cytology, etc., can in no way become the basis for the formation of a theoretical model of the body, without which understanding health is impossible. This article proposes a framework for developing a model of the human body.

Dulong-Petit’s law and Boltzmann’s theoretical proof from the Kinetic Theory of Gases

The main aspect that we will address in this work is the introductory presentation of the empirical law of the specific heats of material bodies, published by Dulong and Petit on April 12, 1819, in the magazine Comptes Rendus. The analytical demonstration of this law appeared for the first time in 1866 in the Doctoral Thesis of the Austrian physicist Ludwig Boltzmann, according to the research carried out by Cássio C. Laranjeiras and presented in his Doctoral Thesis in 2002. In the introduction we discussed how Dulong’s law and Petit played a key role in the subsequent development of a new physics (Quantum Mechanics), when Max Planck changed his research program from electrodynamics to thermodynamics, evidenced in the book: Black Body Theory and the Quantum Discontinuity, 1894-1912, published by Thomas Khun in 1978. Between 1900 and 1912, we observed that fundamental works published by Albert Einstein, Henri Poincaré and Peter Debye explained the mathematical relationship of this empirical law based on Planck’s hypothesis of the quantum of action of blackbody radiation. Despite the controversy over the authorship of the law, whether it would have been formulated in advance by Arago, we agree with Robert Fox that it was the results of Dulong and Petit’s experiments that led to the formulation of the law.

Experimental study on damage of slope under drying and wetting cycle based on DC electric method.

In order to investigate the seepage law and crack development characteristics of dump slopes, as well as the impact on slope stability during drying and wetting cycles, a simulation test slope system was constructed in a rainfall environment, specifically designed to mimic the engineering conditions of dump slope. The apparent resistivity response formula for the seepage and crack development processes was derived based on the three-phase medium theory of rock-soil bodies and Maxwell's conductivity formula. The geoelectric field characteristics pertaining to slope damage and the corresponding patterns of alteration were comprehensively investigated. The results demonstrate a negative correlation between resistivity and slope water content, with resistivity increasing as cracks develop and decreasing with water infiltration. The progression of crack formation in a rainfall environment on a dump slope can be categorized into three stages: The initial phase involves the saturation of the slope as water content increases. Subsequently, the second phase entails the initiation and expansion of capillary zones, along with the formation of dominant waterways. Lastly, the third phase encompasses the formation and expansion of cracks within the dumping site. The occurrence of sudden changes and abnormal fluctuations in apparent resistivity within a saturated slope signifies the presence of cracks and weak surfaces, leading to gradual and irreversible damage. This phenomenon serves as an indicator of slope damage and can be utilized for the early prediction of slope instability.

Efficient convergent boundary integral methods for slender bodies

The interaction of fibers in a viscous (Stokes) fluid plays a crucial role in industrial and biological processes, such as sedimentation, rheology, transport, cell division, and locomotion. Numerical simulations generally rely on slender body theory (SBT), an asymptotic, nonconvergent approximation whose error blows up as fibers approach each other. Yet convergent boundary integral equation (BIE) methods which completely resolve the fiber surface have so far been impractical due to the prohibitive cost of layer-potential quadratures in such high aspect-ratio 3D geometries. We present a high-order Nyström quadrature scheme with aspect-ratio independent cost, making such BIEs practical. It combines centerline panels (each with a small number of poloidal Fourier modes), toroidal Green's functions, generalized Chebyshev quadratures, HPC parallel implementation, and FMM acceleration. We also present new BIE formulations for slender bodies that lead to well conditioned linear systems upon discretization. We test Laplace and Stokes Dirichlet problems, and Stokes mobility problems, for slender rigid closed fibers with (possibly varying) circular cross-section, at separations down to 1/20 of the slender radius, reporting convergence typically to at least 10 digits. We use this to quantify the breakdown of numerical SBT for close-to-touching rigid fibers. We also apply the methods to time-step the sedimentation of 512 loops with up to 1.65 million unknowns at around 7 digits of accuracy.

Managing the Farm

Abstract “Management” is routinely understood by agricultural historians as an exercise in rational expertise, targeted at driving ever more efficient, “businesslike” practices on the farm. However, insights from critical management studies suggest that farm management, as a body of theory and as a form of practice, may be grounded in something less savory than epistemological superiority or the ability to improve farming practice. This article explores how the meaning of farm management changed substantially over the course of the twentieth and early twenty-first centuries, from a pragmatic approach for empowering individual farmers to a more abstract set of theories offering a chimera of control.