Rigid Set Research Articles

Estudiando la corporalidad en el gimnasio: reflexiones prácticas para las ciencias sociales

The study of the body has led to more than five decades of varied and prolific production by social scientists. However, their theoretical and methodological approaches have been as diverse as these investigations. This article, using concrete examples, reflects on the theoretical and methodological implications applied to the study of the body and corporality in the gyms, and aims to show that there is not a rigid set of embodied practices or one type of gym users; on the contrary, they can vary depending on multiple factors such as economic, cultural, or geographical context. It concludes with the author's opinion that Physical Cultural Studies offers an excellent set of tools to investigate the physical and subjective aspects of gym practices.

Simulation of formation waviness on working surfaces rings of roller bearings during centerless grinding operations

In the article was investigated the formation of waviness on working surfaces rings of roller bearings, which causes the appearance of noise and vibration in the bearing units of machines and mechanisms. To establish patterns of appearance of waviness were used some principles of systems theory and mathematic simulation; in particular the establishments of transfer functions, finding the equation of dynamics, usage of Laplace transformations to solve differential equations, building locus diagrams and others.For the purpose of analysis, centerless grinding system, with some simplifications was considered as a linear, continuous, closed dynamic system. On the basis of this was compiled flow-chart of plunge centerless grinding model on rigid shoes, and was found the transfer function. The solution of the system’s characteristic equation revealed influence of waviness on the ground surface and the regeneration process of this waviness on the locus diagram of displacement vector of the workpiece’s center.As the investigation, result established a regularity of change of waviness harmonics depending on the geometry of rigid shoes setting. Management of waviness surface bodies of revolution on centerless grinding operations is an important prerequisite for getting optimum quality parameters of working surfaces of the roller bearing rings and as a result effect on exploitation properties of the bearing, such as noise, durability, and reliability. Using the results of this research will allow choosing such geometry of setting grinding on rigid shoes, which predictably increases or decreases the parameters of a particular harmonic of waviness.

Tropicalization of the moduli space of stable maps

Let $X$ be an algebraic variety and let $S$ be a tropical variety associated to $X$. We study the tropicalization map from the moduli space of stable maps into $X$ to the moduli space of tropical curves in $S$. We prove that it is a continuous map and that its image is compact and polyhedral. Loosely speaking, when we deform algebraic curves in $X$, the associated tropical curves in $S$ deform continuously; moreover, the locus of realizable tropical curves inside the space of all tropical curves is compact and polyhedral. Our main tools are Berkovich spaces, formal models, balancing conditions, vanishing cycles and quantifier elimination for rigid subanalytic sets.

A robust framework for tracking simultaneously rigid and non-rigid face using synthesized data

This paper presents a robust framework for simultaneously tracking rigid pose and non-rigid animation of a single face with a monocular camera. Our proposed method consists of two phases: training and tracking. In the training phase, using automatically detected landmarks and the three-dimensional face model Candide-3, we built a cohort of synthetic face examples with a large range of the three axial rotations. The representation of a face’s appearance is a set of local patches of landmarks that are characterized by Scale Invariant Feature Transform (SIFT) descriptors. In the tracking phase, we propose an original approach combining geometric and appearance models. The purpose of the geometric model is to provide a SIFT baseline matching between the current frame and an adaptive set of keyframes for rigid parameter estimation. The appearance model uses nearest synthetic examples of the training set to re-estimate rigid and non-rigid parameters. We found a tracking capability up to 90° of vertical axial rotation, and our method is robust even in the presence of fast movements, illumination changes and tracking losses. Numerical results on the rigid and non-rigid parameter sets are reported using several annotated public databases. Compared to other published algorithms, our method provides an excellent compromise between rigid and non-rigid parameter accuracies. The approach has some potential, providing good pose estimation (average error less than 4° on the Boston University Face Tracking dataset) and landmark tracking precision (6.3 pixel error compared to 6.8 of one of state-of-the-art methods on Talking Face video).

Abortion: taking the debate seriously.

Voluntarily induced abortion has been under permanent dispute and legal regulations, because societies invariably condemn extramarital pregnancies. In recent decades, a measure of societal tolerance has led to decriminalize and legalize abortion in accordance with one of two models: a more restricted and conservative model known as therapeutic abortion, and the model that accepts voluntary abortion within the first trimester of pregnancy. Liberalization of abortion aims at ending clandestine abortions and decriminalizes the practice in order to increase reproductive education and accessibility of contraceptive methods, dissuade women from interrupting their pregnancy and, ultimately, make abortion a medically safe procedure within the boundaries of the law, inspired by efforts to reduce the incidence of this practice. The current legal initiative to decriminalize abortion in Chile proposes a notably rigid set of indications which would not resolve the three main objectives that need to be considered: 1) Establish the legal framework of abortion; 2) Contribute to reduce social unrest; 3) Solve the public health issue of clandestine, illegal abortions. Debate must urgently be opened to include alternatives in line with the general tendency to respect women's decision within the first trimester of pregnancy.

Effect of reduced visual acuity on precision of two-dimensional tracing movements

PurposeWe intended to assess consequences of reduced visual acuity for performance in a natural simple motor task (tracing) using objective kinematic performance measures. Specifically, we intended to elucidate the kind of relationship between the task performance and best corrected binocular visual acuity and to determine the threshold of visual acuity when task performance starts to deteriorate. MethodsNinety-five individuals with different best corrected visual acuity participated in the study (age 49±12 years, mean±SD, 27 men and 68 women). The participants manually traced maze-like visual patterns of different spatial complexity presented on the screen of a portable notebook computer using Clinical Kinematic Assessment Tool software. Tracing error was computed as performance measure in each trial with a spatial pattern matching technique – rigid point set registration method. ResultsThe segmented linear regression analysis showed that the relation between visual acuity and tracing errors was best described with a regression function having a break point between two data segments. Tracing performance was unaffected by values of visual acuity below 0.2 on logMAR scale, but when logMAR values increased above this critical limit (i.e. when visual acuity is further reduced), tracing errors linearly increased. The rate of the increase of the tracing error correlated with the complexity of visual stimulus shape. ConclusionTesting of fine motor functions with objective kinematic measures during visuomotor tasks may help differentiating between actual effects of reduced visual acuity on eye–hand coordination in individuals with similar levels of impairment of visual acuity.

Aeroelastic behavior of a flag in ground effect

The aeroelastic behavior of a flexible plate subjected to a uniform axial flow is investigated in the presence of a rigid plane set parallel to the plate. It is shown that the ground effect reduces the flutter inflow velocity and strengthens the possibility of using the flag for extracting energy from winds and currents. The numerical analysis is carried out assuming that both the unsteady potential incompressible flow and the plate can be described with 2D models, i.e., a lumped vortex panel method and a nonlinear Euler–Bernoulli beam model, respectively, without losing the essential features of the fluid–structure interaction. Asymmetry of post-critical behavior (limit-cycle oscillations) and sensitivity of the results to the main flag parameters (distance from the ground, mass ratio and damping) are also considered, including also the energy distribution over the identified proper orthogonal modes. The investigated reduction of the flutter velocity in ground effect has been also confirmed with experimental tests relative to a polypropylene flag with and without the rigid panel mimicking the presence of the ground.

Multi-camera parallel tracking and mapping with non-overlapping fields of view

A novel real-time pose estimation system is presented for solving the visual simultaneous localization and mapping problem using a rigid set of central cameras arranged such that there is no overlap in their fields-of-view. A new parameterization for point feature position using a spherical coordinate update is formulated which isolates system parameters dependent on global scale, allowing the shape parameters of the system to converge despite the scale remaining uncertain. Furthermore, an initialization scheme is proposed from which the optimization will converge accurately using only the measurements from the cameras at the first time step. The algorithm is implemented and verified in experiments with a camera cluster constructed using multiple perspective cameras mounted on a multirotor aerial vehicle and augmented with tracking markers to collect high-precision ground-truth motion measurements from an optical indoor positioning system. The accuracy and performance of the proposed pose estimation system are confirmed for various motion profiles in both indoor and challenging outdoor environments, despite no overlap in the camera fields-of-view.

Analysis of Match Performance of Full-backs from Selected European Soccer Leagues

The aim of the present study was the analysis of match activities of full-backs from selected European national soccer leagues. The study sample comprised 30 full-backs playing in the autumn round of the 2014/15 season from five European national top-tier leagues: English Premier League, Spanish Primera Division, German Bundesliga, Russian Priemjer Liga and Italian Serie A. The performance of full-backs (left-back and right-back) from each selected team was analyzed using a professional match analysis system OptaPro which tracks every possible type of ball touch and on the ball action in match covered by a rigid set of definitions. The data for analysis included the total number of passes, total number of crosses, and total number of ball touches performed by the full- backs in three zones of the pitch: attack, midfield and defense. The study results showed that the full-backs from the Spanish Primera Division executed the highest number of passes and crosses as well as ball touches in the attack zone. They also performed the lowest number of passes in the midfield and defense zones, in which the highest percentage of passes was achieved by the full-backs from the German league teams. The study indicates that in modern soccer defenders must possess a high level of offensive skills that can be necessary in the last stage of a team's attack.

Finite rigid sets and homologically nontrivial spheres in the curve complex of a surface

Aramayona and Leininger have provided a "finite rigid subset" 𝔛(Σ) of the curve complex [Formula: see text] of a surface [Formula: see text], characterized by the fact that any simplicial injection [Formula: see text] is induced by a unique element of the mapping class group Mod(Σ). In this paper we prove that, in the case of the sphere with n ≥ 5 marked points, the reduced homology class of the finite rigid set of Aramayona and Leininger is a Mod(Σ)-module generator for the reduced homology of the curve complex [Formula: see text], answering in the affirmative a question posed in [1]. For the surface [Formula: see text] with g ≥ 3 and n ∈ {0, 1} we find that the finite rigid set 𝔛(Σ) of Aramayona and Leininger contains a proper subcomplex X(Σ) whose reduced homology class is a Mod(Σ)-module generator for the reduced homology of [Formula: see text] but which is not itself rigid.

Information Theoretic Shape Matching.

In this paper, we describe two related algorithms that provide both rigid and non-rigid point set registration with different computational complexity and accuracy. The first algorithm utilizes a nonlinear similarity measure known as correntropy. The measure combines second and high order moments in its decision statistic showing improvements especially in the presence of impulsive noise. The algorithm assumes that the correspondence between the point sets is known, which is determined with the surprise metric. The second algorithm mitigates the need to establish a correspondence by representing the point sets as probability density functions (PDF). The registration problem is then treated as a distribution alignment. The method utilizes the Cauchy-Schwarz divergence to measure the similarity/distance between the point sets and recover the spatial transformation function needed to register them. Both algorithms utilize information theoretic descriptors; however, correntropy works at the realizations level, whereas Cauchy-Schwarz divergence works at the PDF level. This allows correntropy to be less computationally expensive, and for correct correspondence, more accurate. The two algorithms are robust against noise and outliers and perform well under varying levels of distortion. They outperform several well-known and state-of-the-art methods for point set registration.

The Canonical Debate Today: Crossing Disciplinary and National Boundaries

The Canonical Debate Today: Crossing Disciplinary and National Boundaries

Deformation events in the Gridino zone, Belomorian Province, Fennoscandian Shield: relationships between mafic dike swarms and eclogite-bearing mélange

Relationships between reference mafic dikes and deformations in the Gridino zone, Belomorian province, Fennoscandian Shield, make it possible to subdivide the deformations into three groups: pre-dike, synmagmatic, and post-dike. The Neoarchaean eclogite-bearing mélange was formed by disintegration of large eclogite slices in the course of ductile flow, which was associated with synkinematic granitoid magmatism and metamorphism varying from the granulite to amphibolite facies. Exotic blocks, including those of eclogites, are distributed in the TTG gneisses as layers and lenses, whose thicknesses range from a few to a few hundred metres and which are conformable with the foliation. Ductile flow brought the rock complexes to the depth level where brittle–ductile deformations were possible. As a result, certain parts of the mélange were deformed in a more rigid setting. A number of mafic dike swarms were emplaced into relatively cold rocks in an extensional environment in the earliest Palaeoproterozoic. The dikes cut across all earlier structures and are thus an important benchmark for distinguishing Neoarchaean and Palaeoproterozoic processes. Post-dike (~1.9 Ga) tectonic activity was associated with local deformations and discrete metamorphic retrogression to amphibolite facies. None of them significantly affected the pre-existing regional structure.

Conexiones de Galois, transformaciones de Chu y enlaces

In this paper we characterize bonds , as defined by Wille, by employing a less rigid set of axioms thus enabling the definition of the category BOND . Since bonds generalize Chu mappings we present a faithful functor between CHU and BOND . Moreover, we propose the Galois morphisms generalizing bonds; this allows us to define the category MGI . Lastly, we suggest a general method to construct categories of adjunctions from any given category. The category of adjunctions generated from the category of order-preserving Galois connections, named MGP , turns out to be equivalent to the category MGI .

Maxillary advancement with rigid external distractor device and mandibular setback in a severe Class III adult patient

Class III skeletal malocclusion, which is one of the most complainable anomaly by patients can be the result of mandibular prognathism and/or maxillary deficiency. With the advancements in surgical techniques and knowledge, today bimaxillary surgical procedures are frequently used to correct this anomaly so that only mandibular set back operations had been performed in the past. Distraction osteogenesis or callus distraction, which is a process of bone regeneration between the surfaces of vascularized bone segments separated by gradual distraction is a method of bone generation without using bone or soft-tissue grafts. The purpose of this report is to present the orthodontic-orthognathic treatment of a patient with severe Class III skeletal malocclusion having ankylosing spondylitis with the use of a rigid external distraction and mandibular set back technique.

Patient safety and surgical innovation–complementary or mutually exclusive?

Safety vs. innovationSafety and innovation are not and need not be antago-nists, but synonyms. If innovation is driven by safety, wecan hopefully accelerate the rate of innovation desper-ately needed in medicine.In the surgical microcosm, it is not infrequent to hearthe voices of surgical conservatism question innovation:why change the current device or method? It is provento work, it is vetted by years of clinical research, andshould therefore be chosen–because it’s safer. There’snothing wrong with that thought process, is there?There is no doubt that safety is the cornerstone of ourpractice. However, caution and prudence should not bedeterrents for innovation. On the contrary, if youngersurgeons or trainees have the luxury of being attractedto innovation, it is only because their mentors use estab-lished methods and strategies. This creates a setting ofsafety and security in which younger surgeons arerooted. The established surgical practice needs to be oneof absolute focus on safety; only then can the youngergeneration be comfortable enough with the currenttechnologies to look into its shortcomings.Just like creating a safe household and offering chil-dren a rigid set of ground rules and education, anchor-ing residents in safety is a critical initial step. But atsome point, your children will need to experience theirown life. And if you hamper that, your kids will neversurpass you… The role of mentors is therefore to teachand give trainees the tools to practice surgery safely.This will allow them to recreate the same environmentof absolute attention to safety for their own patients.Surgical curriculums are aimed at training residents toreach this stage, not to surpass it. It is good, but not goodenough. Once surgical training has been appropriatelyachieved, it is also the role of mentors to push trainees toventure out further and not fall asleep in the safe mode.They should be encouraged to keep searching. If we wantour field to evolve, we owe it to ourselves, to our patients,and to our trainees not to stop at simply reproducing whatwe have learned, but to improve it.It is thus our role, as teachers, to encourage a mindsetof innovation in medical students and residents, and givethem the tools to pursue innovation safely.Finding unmet needs in surgical practice?Innovation and surgery can be two facets to the sameperson, the same career. However, since the times of il-lustrious surgeon/inventors who could bring their inven-tions directly from the lab to the operating room, thingshave changed. Just like surgeons pursuing basic researchdon’t inject the stem cells they grow in their lab in thepatient they care for on the floor, clinical practice is not aplace to carelessly experience with innovation. And currentrules and regulations ensure that fact thoroughly. However,clinical practice is a unique set for identification of unmeetclinical needs. The surgeon has the unique “privilege” ofwitnessing the shortcomings of current treatments andtheir impact on patients. It is her or his duty to use this“privilege” to improve care. The best innovation, and thesafest innovation, is the one grounded in real problemsolving needs. Only if we identify problems worth solv-ing, will we develop solutions worth pursuing. And assurgeons, these solutions often take the shape of de-vices, which is exactly what medtech innovation is:Medical or surgical technology (Medtech) innovationrefers the process whereby scientific discoveries, whichcould solve clinical problems, are driven forward acrossthe translational gap into a device used in clinical prac-tice [1,2].Training to innovateSo you’ve identified an unmet need. Maybe invented asolution… Now what?Navigating the requirement of medical technology de-velopment is actually only getting more and more com-plex: what regulatory pathway is required in the US forthe device to be FDA cleared or approved, or CE marked

Caudate nucleus‐dependent navigational strategies are associated with increased use of addictive drugs

This study aimed to investigate the relationship between navigational strategies and the use of abused substances in a sample of healthy young adults. Navigational strategies were assessed with the 4-on-8 virtual maze (4/8VM), a task previously shown to dissociate between hippocampal-dependent spatial navigational strategies and caudate nucleus-dependent stimulus-response navigational strategies. Spatial strategies involve learning the spatial relationships between the landmarks in an environment, while response learning strategies involve learning a rigid set of stimulus-response type associations, e.g., see the tree, turn left. We have shown that spatial learners have increased gray matter and fMRI activity in the hippocampus compared with response learners, while response learners have increased gray matter and fMRI activity in the caudate nucleus. We were interested in the prevalence of use of substances of abuse in spatial and response learners because of the evidence that people who score high on traits such as novelty seeking, sensation seeking, reward seeking, and impulsivity, are more cue-responsive and more likely to use substances of abuse. Since response learners show increased activity and gray matter in the caudate nucleus of the striatum, which is a brain area involved in addiction, we hypothesized that response learners would have a greater use of abused substances than spatial learners. Fifty-five young adults were tested on the 4/8VM and completed a time-line follow-back assessment of drug and alcohol use. We found that response learners had smoked a significantly greater number of cigarettes in their lifetime than spatial learners, were more likely to have used cannabis, and had double the lifetime alcohol consumption. We discuss the possible relationship between substance abuse and response strategies as well as the implications for the hippocampus, risks of neurological and psychiatric disorders, and healthy cognition. © 2013 The Authors. Hippocampus Published by Wiley Periodicals, Inc.

The woman in the 360 Mirror: What Not To Wear and the feminist construction of reality

Abstract In the last decade, ‘makeover’ reality television has become popular. Feminist scholars in particular have focused on this genre, analysing the ways in which makeover programmes reinforce specific definitions of femininity, class, and sexuality. Academics have been especially critical of the show What Not To Wear, arguing that female guests are demoralized by hosts who prescribe a rigid set of rules for dressing. Many feminist writers perceive the subjects of each week’s episode as unwilling, insecure women who yield their individuality to the dictates of the programme’s stylists. We contend these articles ignore one of the basic tenets of feminist research: the subject must be given agency and allowed to define her experience in her own words. We argue feminists should start from the presumption that these women know how they feel and mean what they say, and even allow them to participate in exploring the meaning of the makeover. To this end, we closely examined several episodes of What Not To Wear that focus on making over highly educated women (several of whom exhibit high levels of gender consciousness) in order to explore how these women understand and interpret their experiences. Also, we interviewed an actual participant in the programme and discussed these issues with her. What results is a more nuanced analysis of what women experience when they are told ‘what not to wear’, in which the subjects smoothly integrate the aspects of the makeover that resonate positively with their sense of self, and leave the rest behind.

Simulation of the Head-On Collision between Heavy Truck and Rigid Guardrail

This paper mainly studied the collision between heavy truck and rigid guardrail. The integral finite element models were established via respectively building the finite element model of truck and rigid guardrail and setting parameters of head-on collision. Then the paper did relative simulation and calculation, and analyzed the curves of vehicle speed, accelerated speed and energy in collision process. The whole process above used LS-DYNA to calculate, ANSYS to do pretreatment and LSPREPOST to do post-treatment in order to test collision safety. Compared with relative documents, the established model is basically correct and accords with the regular pattern of collision simulation.

Non-existence of prescribable conformally equivariant dilatation in space

In this paper, we study the prescribable conformally equivariant dilatations for orientation preserving quasiconformal homeomorphisms. The complex dilatation is a prescribable conformally equivariant dilatation in R. A Schottky set is a subset of the unit sphere S whose complement is the union of at least three disjoint open balls. By using the result of Bonk, Kleiner, and Merenkov that there are rigid Schottky sets of positive measure in each dimension at least 3, we prove that it is not possible to have a prescribable conformally equivariant dilatation in R, where n ≥ 3.