Reverse Engineering of Self-Propelled Anguilliform Swimmers

2008 ◽  
Vol 58 ◽  
pp. 203-211
Author(s):  
Stefan Kern ◽  
Philippe Chatelain ◽  
Petros Koumoutsakos

Biological mimesis pertains usually to the translation of a natural form or mechanism into an engineering design. Mimesis however can also apply to the design process itself as one may employ the principles of natural evolution to the optimization of engineering problems. As an exemplary case study for this approach, we present the application of an Evolutionary Strategy to the optimization of anguilliform swimming. This investigation uses three-dimensional simulations of the flow past a self-propelled body. The motion of the body is not specified a priori but is instead the result of a reverse engineering process. This procedure helps us identify systematically the links between swimming kinematics and biological function. Three distinct objectives are considered: the swimming efficiency, the burst swimming speed, and the acoutic far field signature. We focus on the acoustic and dynamic features, and in particular, we extract phaseshift information for motion controllers..

2020 ◽  
Vol 14 (3) ◽  
Author(s):  
Miguel Nobre Castro ◽  
Tariq Rahman ◽  
Kristen Faith Nicholson ◽  
John Rasmussen ◽  
Shaoping Bai ◽  
...  

Abstract Passive arm-assistive devices play an important role in the rehabilitation of patients with neuromuscular disorders or injuries by overcoming their motor deficit. Routine human activities such as feeding are not possible without the aid provided by one of these devices or by a caregiver. In this study, a body-powered assistive device was designed for feeding purposes using a compact spherical scissors mechanism and zero-free-length (ZFL) springs (rubber bands) to leverage the patient's residual biceps and healthy triceps function. This partially balanced and lightweight orthosis was also projected to accommodate the spring attachment points closer to the elbow joint center. The performance of the prototype was evaluated on a young adult with bilateral amyoplasia of the biceps due to arthrogryposis who could not initially reach the superior anterior aspect of the close-to-torso region of the reachable three-dimensional (3D) workspace (RWS). That was accomplished by measuring the anatomical RWS of the patient before and while wearing the device. The results show that the patient, with the assistance provided by the device, was able to attain positions in the frontal close-to-torso region of the body that included reaching her mouth, thus enabling independent feeding.


2012 ◽  
Vol 20 (04) ◽  
pp. 1250021 ◽  
Author(s):  
LOUIS KOVALEVSKY ◽  
PIERRE LADEVÈZE ◽  
HERVÉ RIOU ◽  
MARC BONNET

This paper proposes an extension of the variational theory of complex rays (VTCR) to three-dimensional linear acoustics, The VTCR is a Trefftz-type approach designed for mid-frequency range problems and has been previously investigated for structural dynamics and 2D acoustics. The proposed 3D formulation is based on a discretization of the amplitude portrait using spherical harmonics expansions. This choice of discretization allows to substantially reduce the numerical integration work by taking advantage of well-known analytical properties of the spherical harmonics. It also permits (like with the previous 2D Fourier version) an effective a priori selection method for the discretization parameter in each sub-region, and allows to estimate the directivity of the pressure field by means of a natural definition of rescaled amplitude portraits. The accuracy and performance of the proposed formulation are demonstrated on a set of numerical examples that include results on an actual case study from the automotive industry.


Resonance ◽  
2020 ◽  
Vol 1 (3) ◽  
pp. 267-278
Author(s):  
Müge Turan

Ventriloquism, Edison’s playback, and the sound film base their appeal to spectators primarily on the tension between the two-dimensional image and three-dimensional sound, between space and surface, as well as between body and voice. My focus is on the disembodied voice in cinema, the voice with no body attached. The meanings attached to the unaccommodated or unlocatable voices in various kinds of ventriloquism seem to produce just such a suspension. The opening of the connection between a voice and a body as its source reminds us of the voice as a partial object in the writings of Jacques Lacan, as well as Rick Altman’s model of ventriloquism, in which whoever controls sound in film is a ventriloquist who “uses” the body, manipulating it as if it were a puppet. This notion becomes fascinatingly complicated when applied to The Exorcist (1973, William Friedkin). The Exorcist stages the battle between the forces of sound and image, body and voice, elevating it to a terrifying good-versus-evil theological level. This battle extends the diegetic narrative to become a battle between two actors (the voice actor and the actor seen on screen) trying to share one body, a split between two personalities. The film is an exceptional case study that allows us to examine the ways in which cinema contributes to and mediates the ventriloquial act, as well as the roles of the visual, aural, and tactile perceptual channels and their relation to each other in the cinematic experience, in particular in the horror genre.


Author(s):  
Marelvy Camacaro ◽  
Alberto Colina ◽  
Mihai Zissu

La presente investigación se realizó con el objetivo de analizar las variables cinemáticas que se manifiestan en la técnica del pateo en el fútbol a partir de criterios de eficiencia biomecánicos. Fue una investigación de nivel descriptivo, con un diseño de campo, basado en un estudio de caso con una atleta de 15 años. Se utilizó el método videográfico tridimensional (3D) con los enfoques: cuantitativo (programa “Human v 5.0”) y cualitativo (escala Likert). Se cuantificaron las variables cinemáticas mediante pre y pos test. Se establecieron criterios de eficiencia para optimizar variables biomecánicas en las fases: Preparatoria y Pateo. Así, se orientó el entrenamiento de la adolescente en función de fortalezas y debilidades identificadas desde la perspectiva biomecánica, lo que permitió optimizar la técnica de los miembros inferiores, dominante y no dominante. Entre otros resultados, destacó el aumento de sincronización y consecuente mejoría del patrón temporal de movimiento lo que facilitó la coordinación de impulso parcial, y por ende la transferencia de energía del cuerpo hacia el balón, incidiendo positivamente en la velocidad resultante, trayectoria y precisión del balón con lo cual aumentó la frecuencia del gol, hecho que incidió en el rendimiento y perfil de la joven, destacándose en la posición lateral con un manejo eficiente del balón por ambos perfiles. The present investigation was carried out with the objective of analyzing the kinematic variables that are manifested in the kicking technique in soccer based on biomechanical efficiency criteria. It was a descriptive level investigation, with a field design, based on a case study with a 15-year-old athlete. The three-dimensional (3D) videographic method was used with the approaches: quantitative (“Human v 5.0” program) and qualitative (Likert scale). Kinematic variables were quantified by pre and posttest. Efficiency criteria were established to optimize biomechanical variables in the phases: Preparatory and Kicking. Thus, the adolescent's training was oriented according to the strengths and weaknesses identified from the biomechanical perspective, which allowed optimizing the technique of the dominant and non-dominant lower limbs. Among other results, the increase in synchronization and consequent improvement in the temporal pattern of movement stood out, which facilitated the coordination of partial impulse, and therefore the transfer of energy from the body to the ball, positively influencing the resulting speed, trajectory and precision of the ball which increased the frequency of the goal, a fact that affected the performance and profile of the young woman, standing out in the lateral position with an efficient handling of the ball by both profile.


Author(s):  
O. Faroon ◽  
F. Al-Bagdadi ◽  
T. G. Snider ◽  
C. Titkemeyer

The lymphatic system is very important in the immunological activities of the body. Clinicians confirm the diagnosis of infectious diseases by palpating the involved cutaneous lymph node for changes in size, heat, and consistency. Clinical pathologists diagnose systemic diseases through biopsies of superficial lymph nodes. In many parts of the world the goat is considered as an important source of milk and meat products.The lymphatic system has been studied extensively. These studies lack precise information on the natural morphology of the lymph nodes and their vascular and cellular constituent. This is due to using improper technique for such studies. A few studies used the SEM, conducted by cutting the lymph node with a blade. The morphological data collected by this method are artificial and do not reflect the normal three dimensional surface of the examined area of the lymph node. SEM has been used to study the lymph vessels and lymph nodes of different animals. No information on the cutaneous lymph nodes of the goat has ever been collected using the scanning electron microscope.


Author(s):  
D. L. Callahan

Modern polishing, precision machining and microindentation techniques allow the processing and mechanical characterization of ceramics at nanometric scales and within entirely plastic deformation regimes. The mechanical response of most ceramics to such highly constrained contact is not predictable from macroscopic properties and the microstructural deformation patterns have proven difficult to characterize by the application of any individual technique. In this study, TEM techniques of contrast analysis and CBED are combined with stereographic analysis to construct a three-dimensional microstructure deformation map of the surface of a perfectly plastic microindentation on macroscopically brittle aluminum nitride.The bright field image in Figure 1 shows a lg Vickers microindentation contained within a single AlN grain far from any boundaries. High densities of dislocations are evident, particularly near facet edges but are not individually resolvable. The prominent bend contours also indicate the severity of plastic deformation. Figure 2 is a selected area diffraction pattern covering the entire indentation area.


Author(s):  
Pramukti Dian Setianingrum ◽  
Farah Irmania Tsani

Backgroud: The World Health Organization (WHO) explained that the number of Hyperemesis Gravidarum cases reached 12.5% of the total number of pregnancies in the world and the results of the Demographic Survey conducted in 2007, stated that 26% of women with live births experienced complications. The results of the observations conducted at the Midwife Supriyati Clinic found that pregnant women with hyperemesis gravidarum, with a comparison of 10 pregnant women who examined their contents there were about 4 pregnant women who complained of excessive nausea and vomiting. Objective: to determine the hyperemesis Gravidarum of pregnant mother in clinic. Methods: This study used Qualitative research methods by using a case study approach (Case Study.) Result: The description of excessive nausea of vomiting in women with Hipermemsis Gravidarum is continuous nausea and vomiting more than 10 times in one day, no appetite or vomiting when fed, the body feels weak, blood pressure decreases until the body weight decreases and interferes with daily activities days The factors that influence the occurrence of Hyperemesis Gravidarum are Hormonal, Diet, Unwanted Pregnancy, and psychology, primigravida does not affect the occurrence of Hyperemesis Gravidarum. Conclusion: Mothers who experience Hyperemesis Gravidarum feel nausea vomiting continuously more than 10 times in one day, no appetite or vomiting when fed, the body feels weak, blood pressure decreases until the weight decreases and interferes with daily activities, it is because there are several factors, namely, hormonal actors, diet, unwanted pregnancy, and psychology.


2020 ◽  
Vol 26 ◽  
Author(s):  
Cristian Muresanu ◽  
Siva G. Somasundaram ◽  
Sergey V. Vissarionov ◽  
Liliya V. Gavryushova ◽  
Vladimir N. Nikolenko ◽  
...  

Background: From the evidence of failed injection-based growth factor therapies, it has been proposed that a naturally triggered uninterrupted blood circulation of the growth factors would be superior. Objective: We seek to stimulate discussions and more research about the possibility of using the already available growth factors found in the prostate gland and endometrium by starting a novel educable physiology, known as biological transformations controlled by the mind. Methods: We summarized the stretch-gated ion channel mechanism of the cell membrane, and offer several practical methods that can be applied by anyone, in order to stimulate and enhance the blood circulation of the growth factors from the seminal fluid to sites throughout the body. This details the practical application of our earlier published studies about biological transformations. Results: A previously reported single-patient case study has been extended, adding more from his personal experiences continually improving this novel physiological training and extending the ideas from our earlier findings in detail. Conclusion: The biological transformation findings demonstrate the need additional research to establish the benefits of these natural therapies to repair and rejuvenate tissues affected by various chronic diseases or aging processes.


2021 ◽  
pp. 002087282096742
Author(s):  
Emmison Muleya

Successful social reintegration is critical if we are to reduce recidivism and crime in general. This voice of people article presents a background case for why effective offender reintegration services are key in South Africa, and the Eastern Cape in particular, through an example of the Offender Reintegration programme rendered by the National Institute of Crime Prevention and Reintegration of Offenders (NICRO). Apart from the paucity of literature on offender reintegration, very few voices from people working directly with these former offenders are ever heard. Therefore, this article seeks to address this gap by contributing to the body of knowledge on offender social reintegration.


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